Endocrine surgery  is a surgical sub-speciality focusing on surgery of the  endocrine glands , including the thyroid gland, the parathyroid glands, the adrenal glands, glands of the endocrine pancreas, and some neuroendocrine glands. [ 1 ]


Surgery of the  thyroid gland  constitutes the bulk of endocrine surgical procedures worldwide. This may be done for a variety of conditions, help ranging from benign  multinodular goiter  to  thyroid cancer . In the United Kingdom it was developed as a separate specialty from general surgery by Richard Welbourne and John Lynn, surgeons at what was then the 'Royal Postgraduate Medical School' and is now the  Hammersmith Hospital  and contains the Department of Thyroid and Endocrine Surgery staffed by consultant surgeons Professor Fausto Palazzo, Professor Neil Tolley and Miss Aimee Di Marco.
Operations involve removal of the thyroid gland ( thyroidectomy ) either as a part of the gland (lobectomy or hemithyroidectomy), or the whole gland (total thyroidectomy). Incomplete resections (sub-total or near total thyroidectomy) are also infrequently performed, but are disfavored by most surgeons [ citation needed ] .


Removal of the parathyroid gland(s) is referred to as  parathyroidectomy  and is most commonly performed for  primary hyperparathyroidism .  Parathyroidectomy is also performed to treat tertiary hyperparathyroidism arising from chronic  kidney failure .


Adrenalectomy , the surgical removal of the adrenal gland, is performed to treat conditions including  Conn syndrome ,  pheochromocytoma , and  adreno-cortical cancer .


Diseases of the endocrine pancreas occur very infrequently; these include  insulinomas ,  gastrinomas  etc. Surgery for these conditions range from simple tumor enucleation to more larger resections.


Endocrine surgery is generally well developed. Endocrine surgery has developed as a sub-specialty surgical category because of the technical nature of these operations and the associated risks of operating in the neck. In  Surgery: Basic Science and Clinical Evidence , the book the efficacy prior research: [ 2 ]


Surgeons and physicians have advanced endocrine surgery by careful description of unusual patients and families with endocrine syndromes...Surgeons have also improved techniques for preparation for surgery and methods...


In the 1970s, a specialty training program at  Hammersmith Hospital  was the primary location for early work in training a large number of surgeons. [ 3 ]  It is well established that complications are much less common if performed by surgeons who do at least 100 thyroid operations per year. In the United Kingdom most thyroid surgery is performed by surgeons doing less than 20 thyroid operations per year. [ citation needed ]  Permanent damage to both voice box nerves is an extreme rarity and needs in most cases a permanent tracheostomy.  Data on the outcomes of all surgeons performing endocrine surgery in the UK is publicly available via the ' British Association of Endocrine and Thyroid Surgeons ' website.


Some surgical teams leave wound drains in place after surgery to the thyroid gland. [ 4 ]  There is no strong evidence that wound drains improve outcomes following surgery and there is low-quality evidence that wound drains increase the length of time a person stays in the hospital following thyroid surgery. [ 4 ]


Endoscopic endonasal surgery  is a  minimally invasive technique  used mainly in  neurosurgery  and   otolaryngology . A neurosurgeon or an otolaryngologist, using an  endoscope  that is entered through the nose, fixes or removes brain defects or tumors in the anterior  skull base . Normally an otolaryngologist performs the initial stage of surgery through the  nasal cavity  and  sphenoid bone ; a neurosurgeon performs the rest of the surgery involving drilling into any cavities containing a neural organ such as the  pituitary gland . The use of endoscope was first introduced in Transsphenoidal Pituitary Surgery by R Jankowsky, J Auque, C Simon et al. in 1992 G (Laryngoscope. 1992 Feb;102(2):198-202).


Antonin Jean Desomeaux, a urologist from Paris, was the first person to use the term, endoscope. [ 1 ]
However, the precursor to the modern endoscope was invented in the 1800s when a physician in Frankfurt, Germany by the name of  Philipp Bozzini , developed a tool to see the inner workings of the body. [ 2 ]  Bozzini called his invention a Light Conductor, or Lichtleiter in German, and later wrote about his experiments on live patients with this device that consisted of an eyepiece and a container for a candle. [ 1 ]  Following Bozzini's success, The University of Vienna starting using the device to test its practicality in other forms of medicine. After Bozzini's device received negative results from live human trials, it had to be discontinued. However,  Maximilian Nitze  and Joseph Leiter used the invention of the light bulb by Thomas Edison to make a more refined device similar to modern day endoscopes. This iteration was used for urological procedures, and eventually otolaryngologists began to use Nitze and Leiter's device for  eustachian tube  manipulation and removal of foreign bodies. [ 2 ]  The endoscope made its way to the US when Walter Messerklinger began teaching David Kennedy at Johns Hopkins Hospital. [ citation needed ]


The  transsphenoidal  and intracranial approaches to pituitary tumors began in the 1800s but with little success. Gerard Guiot popularized the transphenoidal approach which later became part of the neurosurgical curriculum, however he himself discontinued the use of this technique because of inadequate sight. [ 1 ]  In the late 1970s, the endoscopic endonasal approach was used by neurosurgeons to augment microsurgery which allowed them to view objects out of their line of sight. Another surgeon,  Axel Perneczky , is considered to be a pioneer of the use of an endoscope in neurosurgery. Perneczky said that endoscopy, "improved appreciation of micro-anatomy not apparent with the microscope." [ 1 ]


The surgery was pioneered in Algeria by  Bouyoucef Kheireddine  and  Faiza Lalam . [ 3 ] [ 4 ]


The endoscope consists of a glass fiber bundle for cold light illumination, a mechanical housing, and an optics component with four different views: 0 degree for straight forward, 30 degrees for forward plane, 90 degrees for lateral view, and 120 degrees for retrospective view. [ 5 ]  For endoscopic endonasal surgery, rigid rod-lens endoscopes are used for better quality of vision, since these endoscopes are smaller than the normal endoscope used  colonoscopies . [ 2 ]  The endoscope has an eyepiece for the surgeon, but it is rarely used because it requires the surgeon to be in a fixed position. Instead, a video camera broadcasts the image to a monitor that shows the surgical field. [ citation needed ]


Several specialties need to be involved to determine the complete surgical plan. These include: an Endocrinologist, a Neuroradiologist, an Ophthalmologist, a Neurosurgeon, and an Otolaryngologist.


An endocrinologist is only involved in preparation for an endoscopic endonasal surgery, if the tumor is located on the pituitary gland. The tumor is first treated  pharmacologically  in two ways: controlling the levels of  hormones  that the  pituitary gland  secretes and reducing the size of the tumor. If this approach does not work, the patient is referred to surgery. The main types of  pituitary adenomas  are:


A neuroradiologist takes images of the defect so that the surgeon is prepared on what to expect before surgery. This includes identifying the  lesion  or  tumor , controlling the effects of the medical therapy, defining the spatial situation of the lesions, and verifying the removal of the lesions. [ 5 ]   The lesions associated with endoscopic endonasal surgery include:


Some  suprasellar  tumors invade the  chiasmatic cistern , causing impaired vision. In these cases, an ophthalmologist maintains optic health by administering pre-surgical treatment, advising proper surgical techniques so that the optic nerve is not in danger, and managing post-surgery eye care. Common problems include: [ citation needed ]


The transnasal approach is used when the surgeon needs to access the roof of the nasal cavity, the  clivus , or the  odontoid . This approach is used to remove  chordomas ,  chondrosarcoma , inflammatory lesions of the clivus, or  metastasis  in the cervical spine region. The anterior  septum  or posterior septum is removed so that the surgeon can use both sides of the nose. One side can be used for a microscope and the other side for a surgical instrument, or both sides can be used for surgical instruments. [ 2 ]


This approach is the most common and useful technique of endoscopic endonasal surgery and was first described in 1910 concurrently by  Harvey Cushing  and  Oskar Hirsch . [ 6 ] [ 7 ]  This procedure allows the surgeon to access the sellar space, or  sella turcica . The sella is a cradle where the pituitary gland sits. Under normal circumstances, a surgeon would use this approach on a patient with a pituitary adenoma. The surgeon starts with the transnasal approach prior to using the transsphenoidal approach. This allows access to the sphenoid ostium and sphenoid sinus. The sphenoid  ostium  is located on the anterosuperior surface of the sphenoid sinus. The anterior wall of the sphenoid sinus and the sphenoid  rostrum  is then removed to allow the surgeon a panoramic view of the surgical area. [ 2 ]  This procedure also requires the removal of the posterior  septum  to allow the use of both nostrils for tools during surgery. There are several triangles of blood vessels traversing this region, which are just very delicate areas of blood vessels that can be deadly if injured. [ 2 ] [ 8 ]  A surgeon uses stereotactic imaging and a micro Doppler to visualize the surgical field.


The invention of the angled endoscope is used to go beyond the  sella  to the suprasellar (above the sellar) region. This is done with the addition of four approaches. First the transtuberculum and  transplanum  approaches are used to reach the suprasellar  cistern . The lateral approach is then used to reach the medial  cavernous sinus  and  petrous apex . Lastly, the inferior approach is used to reach the superior  clivus .  Endoscopic endonasal transclival approaches are often described according to which segment of the  clivus  is involved in the approach, with the  clivus  typically divided into three regions. [ 9 ]  Depending on which segment of the  clivus  is involved in the surgical approach, different neurovascular structures are placed at risk. The upper third lies inferior to the dorsum sellae and posterior clinoid processes and superior to the petrous apex, the middle third lies at the level of the petrous segments of the internal carotid artery (ICA), and the inferior third extends from the jugular tubercle to the foramen magnum. [ 9 ]  It is important that the Perneczky triangle is treated carefully. This triangle has optic nerves, cerebral arteries, the  third cranial nerve , and the  pituitary stalk . Damage to any of these could provide a devastating post-surgical outcome. [ 2 ] [ 10 ]


The transpterygoidal approach enters through the posterior edge of the  maxillary sinus   ostium  and posterior wall of the maxillary sinus. This involves penetrating three separate sinus cavities: the  ethmoid sinus , the  sphenoidal sinus , and the maxillary sinus. Surgeons use this method to reach the  cavernous sinus , lateral  sphenoid sinus , infra  temporal fossa ,  pterygoid fossa , and the  petrous apex . Surgery includes a uninectomy (removal of the osteomeatal complex), a medial maxillectomy (removal of maxilla), an ethmoidectomy (removal of ethmoid cells and/or ethmoid bone), a sphenoidectomy (removal of part of sphenoid), and removal of the maxillary sinus and the palatine bone. The posterior septum is also removed at the beginning to allow use of both nostrils. [ 2 ]


This approach makes a surgical corridor from the  frontal sinus  to the  sphenoid sinus . This is done by the complete removal of the  ethmoid  bone, which allows a surgeon to expose the roof of the ethmoid, and the medial orbital wall. This procedure is often successful in the removal of small  encephaloceles  of the ethmoid  osteomas  of the  ethmoid sinus  wall or small  olfactory  groove  meningiomas . However, with larger tumors or lesions, one of the other approaches listed above is required. [ 2 ]


For removal of a small tumor, it is accessed through one nostril. However, for larger tumors, access through both nostrils is required and the posterior nasal  septum  must be removed. Then the surgeon slides the endoscope into the nasal  choana  until the sphenoid  ostium  is found. Then the mucosa around the ostium is cauterized for microadenomas and removed completely for macroadenomas. Then the endoscope enters the ostium and meets the sphenoid  rostrum  where the  mucosa  is retracted from this structure and is removed from the  sphenoid sinus  to open the surgical pathway. At this point, imaging and Doppler devices are used to define the important structures. Then the floor of the  sella turcica  is opened with a high speed drill being careful to not pierce the  dura mater . Once the dura is visible, it is cut with microscissors for precision. If the tumor is small, the tumor can be removed by an  en bloc  procedure, which consists of cutting the tumor into many sections for removal. If the tumor is larger, the center of the tumor is removed first, then the back, then the sides, then top of the tumor to make sure that the  arachnoid membrane  does not expand into the surgical view. This will happen if the top part of the tumor is taken out too early. After tumor removal, CSF leaks are tested for with fluorescent dye, and if there are no leaks, the patient is closed. [ 2 ]


This technique is the same as to the sellar region. However the   tuberculum sellae  is drilled into instead of the sella. Then an opening is made that extends halfway down the sella to expose the dura, and the  intercavernous sinuses  is exposed. When the  optic chiasm ,  optic nerve , and  pituitary gland  are visible, the pituitary gland and optic chasm are pushed apart to see the  pituitary stalk . An  ethmoidectomy  is performed, [ 2 ]  the dura is then cut, and the tumor is removed. These types of tumors are separated into two types:


When there is a tumor, injury, or some type of defect at the skull base whether the surgeon used an endoscopic or open surgical method, the problem still arises of providing separation of the  cranial cavity  and cavity between the sinuses and nose to prevent  cerebrospinal fluid  leakage through the opening referred to as a defect. [ 11 ]


For this procedure, there are two ways to start: with a free graft repair or with a vascularized flap repair. The free grafts use secondary material like  cadaver  flaps or titanium mesh to repair the skull base defects, which is very successful (95% without CSF leaks) with small CSF fistulas or small defects. [ 12 ]   The local or regional vascularized flaps are pieces of tissue relatively close to the surgery site that have been mostly freed up but are still attached to the original tissue. These flaps are then stretched or maneuvered onto the desired location. When technology advanced and larger defects could be fixed endoscopically, more and more failures and leaks started to occur with the free graft technique. The larger defects are associated with a wider dural removal and an exposure to high flow CSF, which could be the reason for failure among the free graft. [ 12 ]


This surgery is turned from a very serious surgery into a minimally invasive one through the nose with the use of the endoscope. For instance  craniopharyngiomas  (CRAs) are starting to be removed via this method. Dr. Paolo Cappabianca described the perfect CRA for this surgery to be a median lesion with a solid parasellar component (beside the sellar) or encasement of the main neuromuscular structures that are localized in the subchiasmatic (below the  optic chiasm ) and retrochiasmatic (behind the optic chiasm) regions. He also says that when these conditions are met, endoscopic endonasal surgery is a valid surgical option. [ 13 ]  For a case study on large adenomas, the doctors showed that out of 50 patients, 19 had complete tumor removal, 9 had near complete removal, and 22 had partial removal. The partial removal came from the tumors extending into more dangerous areas. They concluded that endoscopic endonasal surgery was a valid option for surgery if the patients used pharmacological therapy after surgery. [ 14 ]  Another study showed that with endoscopic endonasal surgery 90% of  microadenomas  could be removed, and that 2/3 of normal  macroadenomas  could be removed if they did not go into the  cavernous sinus , which means fragile blood vessel triangles would have to be dealt with so only 1/3 of those patients recovered. [ 15 ]  Endoscopic endonasal approach has been shown even among young patients to be superior to traditional microscopic transsphenoidal surgery. [ 16 ]


The newer 3-D technique is gaining ground as the ideal way to do surgery because it gives the surgeon a better understanding of the spatial configuration of what they are seeing on a computer screen. Dr. Nelson Oyesiku at Emory University helped develop the 3-D technique. In an article he helped write, he and the other authors compared the effects of the 2-D technique vs the 3-D technique on patient outcome. It showed that the 3-D endoscopy gave the surgeon more depth of field and stereoscopic vision and that the new technique did not show any significant changes in patient outcomes during or after surgery. [ 17 ]


In a case study from 2013, they compared the open vs endoscopic techniques for 162 other studies that contained 5,701 patients. [ 18 ]   They only looked at four tumor types: the olfactory groove  meningiomas  (OGM), tuberculum sellae meningiomas (TSM),  craniopharyngiomas  (CRA), and clival  chordomas  (CHO). They looked at gross total resection and  cerebrospinal fluid  (CSF) leaks, neurological death, post-operative visual function, post operative  diabetes insipidus , and post-operative obesity. The study showed that there was a greater chance of CSF leaks with endoscopic endonasal surgery. The visual function improved more with endoscopic surgery for TSM, CRA, and CHO patients. Diabetes insipidus occurred more in open procedure patients. The endoscopic patients showed a higher recurrence rate. In another case study on CRAs, [ 19 ]  they showed similar results with the CSF leaks being more of a problem in endoscopic patients. Open procedure patients showed a higher rate of post operative seizures as well. Both of these studies still suggest that despite the CSF leaks, that the endoscopic technique is still an appropriate and suitable surgical option. Otologic surgery, which is traditionally performed via an open approach using a microscope, may also be performed endoscopically, and is called  Endoscopic Ear Surgery  or EES. [ citation needed ]


Donald Stuart Gann  (1932 – February 3, 2020) was an American  trauma surgeon . He chaired surgical departments at  Case Western Reserve University ,  Brown University ,  Johns Hopkins School of Medicine , and the  University of Maryland School of Medicine . He was a past president of the  Biomedical Engineering Society  and the  American Association for the Surgery of Trauma  [ Wikidata ] .


Gann was born in 1932 [ 1 ]  in  Baltimore  to educator Beatrice Gann and physician Mark Gann. He was raised on  Eutaw Street  in Baltimore and  Catonsville, Maryland . Gann attended  Baltimore Polytechnic Institute  until leaving in 11th grade to attend college at the age of 16. He double majored in physics and philosophy at  Dartmouth College , graduating with  magna cum laude  and  Phi Beta Kappa  honors in 1952. Gann completed a medical degree at  Johns Hopkins School of Medicine  in 1956. He conducted a residency in surgery at Johns Hopkins University and an assistant residency at  MedStar Union Memorial Hospital . [ 2 ]  Gann trained under  Vernon Benjamin Mountcastle  in neurosurgery before shifting to endocrine surgery. [ 3 ]


In 1967, Gann was the first chair of the biomedical engineering department at  Case Western Reserve University . In 1970, he became a professor of biomedical engineering and associate professor of surgery. In 1974, Gann became a professor of  emergency medicine  and director of the division of emergency medicine. From 1979 to 1988, Gann was chair of the new department of surgery at  Brown University  and was the second surgeon in chief of  Rhode Island Hospital . He led the division of surgical  critical care  at the  University of Maryland Medical Center  from 1992 to 2000. He held other positions at  University of Maryland School of Medicine  (UMMS) including section chief of  trauma surgery  and critical care, and  endocrine surgery . He retired from UMMS in 2010. [ 2 ]


Gann and physiologist Dan Darlington founded Shock Therapeutics Biotechnologies Inc. based on a patent for treating  hemorrhagic shock . [ 2 ]


He was the president of the  Biomedical Engineering Society  (1971–1972) and of the  American Association for the Surgery of Trauma  [ Wikidata ]  from 1987 to 1988. [ 2 ]


Gann was a  Quaker . He was married to nurse practitioner Gail Burgan. He had three sons and a daughter. He died on February 3, 2020, at his  Brooklandville, Maryland , residence. Gann was 87. [ 2 ]


Gann was a member of the  American Association of Endocrine Surgeons ,  American College of Surgeons , Halsted Society,  Endocrine Society , and the Southern Surgical Association. [ 2 ]


Parathyroidectomy  is the  surgical  removal of one or more of the (usually) four  parathyroid glands . This procedure is used to remove an  adenoma  or  hyperplasia  of these glands when they are producing excessive  parathyroid hormone  (PTH):  hyperparathyroidism . The glands are usually four in number and located adjacent to the posterior surface of the  thyroid gland , but their exact location is variable. When an elevated PTH level is found, a  sestamibi scan  or an  ultrasound  may be performed in order to confirm the presence and location of abnormal parathyroid tissue.


The main indication for parathyroidectomy is primary hyperparathyroidism, a condition in which one or more of the parathyroid glands produce excessive parathyroid hormone. Not all cases of primary hyperparathyroidism require surgery, but it is recommended if the condition causes significant symptoms or if it affects the kidneys ( nephrocalcinosis ) or bone health ( osteoporosis ), and also in people under 50 even if they do not have symptoms. [ 1 ]  It is not always possible to anticipate if a parathyroid tumor is  malignant  (i.e. capable of invading other tissues or  spreading elsewhere ). Any suspicion of parathyroid carcinoma is therefore also an indication for surgery. [ 1 ]


Parathyroidectomy may also be required in secondary hyperparathyroidism. This situation arises mainly in people with severe  chronic kidney disease  in which the parathyroid glands are overactive to compensate for the low calcium and vitamin D levels often present in CKD. In many cases, the parathyroid hormone production improves when these abnormalities are treated with medication. A small proportion, however, have persistently raised hormone levels six months after treatment has started, thought to be autonomous production of hormone by the glands and loss of feedback mechanisms. In this situation surgical parathyroidectomy may be required, especially if calcium and phosphate levels remain elevated, there is calcium deposition in the wall of blood vessels ( calciphylaxis  in severe cases) or there is worsening bone disease. In people on  dialysis , parathyroidectomy can improve their survival. It does appear that the procedure may be underused. [ 2 ]


The  operation  requires a  general anesthetic  (unconscious and pain free) or a  local anesthetic  (pain free). The surgeon makes an incision around an inch long in the neck just under the  larynx  ( Adam's apple ), and locates the offending parathyroid glands. Preoperative testing using  sestamibi scanning  can help identify the location of glands. It can also be used to limit the extent of surgical exploration when used in conjunction with intraoperative PTH hormone monitoring. [ 3 ]   The particular problem or disease process will determine how many of the parathyroid glands are removed. Some parathyroid tissue must be left in place to help prevent  hypoparathyroidism .


Recovery after the operation tends to be swift. The  PTH  level is back to normal within 10–15 minutes, and can be confirmed by intraoperative rapid assessment during the operation.  However, the remaining parathyroid glands may take hours to several weeks to return to their normal functioning levels (as they may have become dormant).  Calcium supplements are therefore often required to prevent symptoms of  hypocalcemia  and to restore lost bone mass. [ 4 ]


The patient is placed in a semi-Fowler position and the neck is extended. An abbreviated Kocher incision is made and the platysma muscle is dissected horizontally. The strap muscles are released off of the thyroid gland. Then the thyroid gland is mobilized and the parathyroid arterial blood supply is suture ligated. The entire parathyroid adenoma is identified and dissected out. Intraoperative PTH monitoring can begin at this time and will show falling PTH levels if the entire adenoma has been resected. [ 5 ]


While mild hypocalcemia is common after partial parathyroidectomy, some people experience persistently prolonged low calcium levels. This is called  hungry bone syndrome . Despite the reactivation of unresected parathyroid glands producing normal to elevated levels of PTH, serum calcium continues to be low. The balance between calcium influx and efflux within the bone continues to be disrupted, favoring the former. The bone is said to be "hungry" as it consumes minerals without regard to PTH; calcium, magnesium, and phosphate continue to be deposited into the bones, resulting in hypocalcemia, hypomagnesemia, and hypophosphatemia. Prolonged calcium supplementation may be required. Hungry bone syndrome is particularly common in people who are on long-term regular dialysis. [ 2 ] [ 6 ]


Pinealectomy  is a  surgical procedure  in which the  pineal gland  is removed. It is performed only in rare cases, where a  pineocytoma  or a  pineal gland cyst  has become life-threatening. [ citation needed ]


This  surgery  article is a  stub . You can help Wikipedia by  expanding it .


A  thyroidectomy  is an operation that involves the  surgical  removal of all or part of the  thyroid gland .  In  general surgery , endocrine or head and neck surgeons often perform a thyroidectomy when a patient has thyroid  cancer  or some other condition of the thyroid  gland  (such as  hyperthyroidism ) or goiter. Other indications for surgery include cosmetic (very enlarged thyroid), or symptomatic obstruction (causing difficulties in swallowing or breathing). Thyroidectomy is a common surgical procedure that has several potential complications or sequelae including: temporary or permanent change in voice, temporary or permanently low calcium, need for lifelong thyroid hormone replacement, bleeding, infection, and the remote possibility of airway obstruction due to bilateral vocal cord paralysis.  Complications are uncommon when the procedure is performed by an experienced surgeon. [ citation needed ]


The thyroid produces several  hormones , such as  thyroxine  (T4),  triiodothyronine  (T3), and  calcitonin . After the removal of a thyroid, patients usually take a prescribed oral synthetic thyroid hormone— levothyroxine  (Synthroid)—to prevent  hypothyroidism . Less extreme variants of thyroidectomy include:


A thyroidectomy should not be confused with a  thyroidotomy  ( thyrotomy ), which is a cutting into ( ‑otomy ) the thyroid, not a removal ( ‑ectomy , literally “out-cutting”) of it. A thyroidotomy can be performed to get access for a  median laryngotomy , or to perform a  biopsy . (Although technically a biopsy involves removing some tissue, it is more frequently categorized as an  ‑otomy  than an  ‑ectomy  because the volume of tissue removed is minuscule.)


Traditionally, the thyroid has been removed through a neck incision that leaves a permanent scar. More recently,  minimally invasive  and "scarless" approaches such as  transoral thyroidectomy  have become popular in some parts of the world. In the United States it is a common procedure, performed over 100,000 times per year.  [ 1 ] [ 2 ] [ 3 ]


Thyroidectomy is used in the treatment of:


Al-Zahrawi , a tenth century  Arab  physician, sometimes referred to as the "father of surgery", [ 8 ]  is credited with the performance of the first thyroidectomy. [ 9 ]


Media related to  Thyroidectomy  at Wikimedia Commons


Vascular surgery  is a surgical subspecialty in which  vascular diseases  involving the  arteries ,  veins , or  lymphatic vessels , are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from  general  and  cardiovascular surgery  where it refined the management of just the vessels, no longer treating the heart or other organs. Modern vascular surgery includes open surgery techniques, endovascular (minimally invasive) techniques and medical management of vascular diseases - unlike the parent specialities. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons also are called to assist other physicians to carry out surgery near vessels, or to salvage vascular injuries that include hemorrhage control, dissection, occlusion or simply for safe exposure of vascular structures. [ 1 ]


Early leaders of the field included Russian surgeon  Nikolai Korotkov , noted for developing early surgical techniques, American  interventional radiologist   Charles Theodore Dotter  who is credited with inventing minimally invasive angioplasty (1964), and Australian Robert Paton, who helped the field achieve recognition as a specialty. Edwin Wylie of San Francisco was one of the early American pioneers who developed and fostered advanced training in vascular surgery and pushed for its recognition as a specialty in the United States in the 1970s. The most notable historic figure in vascular surgery is the 1912 Nobel Prize winning surgeon,  Alexis Carrel  for his techniques used to suture vessels.


The specialty continues to be based on operative arterial and venous surgery but since the early 1990s has evolved greatly. There is now considerable emphasis on minimally invasive alternatives to surgery. The field was originally pioneered by  interventional radiologists  like Dr.  Charles Dotter , who invented angioplasty using serial dilatation of vessels.


The surgeon Dr.  Thomas J. Fogarty  invented a  balloon catheter , designed to remove clots from occluded vessels, which was used as the eventual model to do endovascular angioplasty. Further development of the field has occurred via joint efforts between  interventional radiology , vascular surgery, and  interventional cardiology . This area of vascular surgery is called Endovascular Surgery or Interventional Vascular Radiology, a term that some in the specialty append to their primary qualification as Vascular Surgeon. Endovascular and endovenous procedures (e.g.,  EVAR ) can now form the bulk of a vascular surgeon's practice.


The treatment of the aorta, the body's largest artery, dates back to Greek surgeon Antyllus, who first performed surgeries for various aneurysms in the second century AD. Modern treatment of aortic diseases stems from development and advancements from  Michael DeBakey  and  Denton Cooley . In 1955, DeBakey and Cooley performed the first replacement of a thoracic aneurysm with a homograft. In 1958, they began using the  Dacron  graft, resulting in a revolution for surgeons in the repair of aortic aneurysms. He also was first to perform cardiopulmonary bypass to repair the ascending aorta, using antegrade perfusion of the brachiocephalic artery.


Dr.  Ted Diethrich , one of Dr. DeBakey's associates, went on to pioneer many of the  minimally invasive  techniques that later became hallmarks of endovascular surgery. [ 2 ]  Dietrich later founded the  Arizona Heart Hospital  in 1998 and served as its medical director from 1998 to 2010. In 2000, Diethrich performed the first endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm. Dietrich trained several future leaders in the field of endovascular surgery at the Arizona Heart Hospital including  Venkatesh Ramaiah, MD [ 3 ]  who succeeded him as medical director of the institution in 2010. [ 4 ]


The development of endovascular surgery has been accompanied by a gradual separation of vascular surgery from its origin in  general surgery . Most vascular surgeons would now confine their practice to vascular surgery and, similarly, general surgeons would not be trained or practise the larger vascular surgery operations or most endovascular procedures. More recently, professional vascular surgery societies and their training program have formally separated vascular surgery into a separate specialty with its own training program, meetings and accreditation. Notable societies are  Society for Vascular Surgery  (SVS), USA; Australia and New Zealand Society of Vascular Surgeons (ANZSVS). Local societies also exist (e.g., New South Wales Vascular and Melbourne Vascular Surgical Association (MVSA)). Larger societies of surgery actively separate and encourage specialty surgical societies under their umbrella (e.g.,  Royal Australasian College of Surgeons  (RACS)).


Arterial and venous disease treatment by  angiography ,  stenting , and non-operative varicose vein treatment  sclerotherapy ,  endovenous laser treatment  have largely replaced major surgery in many first world countries. These procedures provide reasonable outcomes that are comparable to surgery with the advantage of short hospital stay (day or overnight for most cases) with lower morbidity and mortality rates. Historically performed by interventional radiologists, vascular surgeons have become increasingly proficient with endovascular methods. [ 5 ]  The durability of endovascular arterial procedures is generally good, especially when viewed in the context of their common clinical usage i.e. arterial disease occurring in elderly patients and usually associated with concurrent significant patient comorbidities especially ischemic heart disease. The cost savings from shorter hospital stays and less morbidity are considerable but are somewhat balanced by the high cost of imaging equipment, construction and staffing of dedicated procedural suites, and of the implant devices themselves.
The benefits for younger patients and in venous disease are less persuasive but there are strong trends towards nonoperative treatment options driven by patient preference, health insurance company costs, trial demonstrating comparable efficacy at least in the medium term.


A recent trend in the United States is the stand-alone day angiography facility associated with a private vascular surgery clinic, thus allowing treatment of most arterial endovascular cases conveniently and possibly with lesser overall community cost. [ citation needed ]  Similar non-hospital treatment facilities for non-operative vein treatment have existed for some years and are now widespread in many countries.


NHS England  conducted a review of all 70 vascular surgery sites across England in 2018 as part of its Getting It Right First Time programme. The review specified that vascular hubs should perform at least 60 abdominal aortic aneurysm procedures and 40 carotid endarterectomies a year. 12 trusts missed both targets and many more missed one of them. A programme of concentrating vascular surgery in fewer centres is proceeding. [ 6 ]


Vascular surgery encompasses surgery of the  aorta ,  carotid arteries , and  lower extremities , including the  iliac ,  femoral ,  vascular trauma  and  tibial arteries . Vascular surgery also involves surgery of veins, for conditions such as  May–Thurner syndrome  and for  varicose veins . In some regions, vascular surgery also includes  dialysis access surgery  and  transplant surgery .


The management of arterial pathology excluding coronary and intracranial disease is within the scope of vascular surgeons. Disease states generally arise from narrowing of the arterial system known as  stenosis  or abnormal dilation referred to as an  aneurysm . There are multiple mechanisms by which the arterial lumen can narrow, the most common of which is  atherosclerosis . [ 7 ]  Symptomatic stenosis may also result from a complication of  arterial dissection . Other less common causes of stenosis include  fibromuscular dysplasia , radiation induced fibrosis or  cystic adventitial disease . Dilation of an artery which retains histologic layers is called an aneurysm. An aneurysms can be fusiform (concentric dilation), saccular (outpouching) or a combination of the two. Arterial dilation which does not contain three histologic layers is considered a  pseudoaneurysm . Additionally, there are a number of congenital vascular anomalies which lead to symptomatic disease that are managed by the vascular surgeon, a few of which include  aberrant subclavian artery ,  popliteal artery entrapment syndrome  or persistent sciatic artery. [ 8 ]  Vascular surgeons treat arterial diseases with a range of therapies including lifestyle modification, medications, endovascular therapy and surgery.


An  abdominal aortic aneurysm  (AAA) refers to aneurysmal dilation of the aorta confined to the abdominal cavity. Most commonly, aneurysms are asymptomatic and located in the infrarenal position. Often, they are discovered incidentally or on screening exams in patients with risk factors such as a history of smoking. Patients with aneurysms which have a diameter less than 5 cm are at <1% rupture risk per year. When the aneurysm meets size criteria it can be treated with  aortic replacement  or  EVAR .


Thoracic aortic aneurysms  are contained in the chest. Aneurysms of the descending aorta can often be treated with thoracic endovascular aortic repair or  TEVAR . Treating aneurysms which involve the ascending aorta are generally within the scope of cardiac surgeons, but upcoming endovascular technology may allow for a more minimally invasive approach in some patients.


Thoroacoabdominal aneurysms are those which span the chest and abdominal cavities. The  Crawford classification  was developed and describes five types of thoracoabdominal aneurysms. [ 9 ]


In addition to treating aneurysms which arise from the  aorta , vascular surgeons also treat aneurysms elsewhere in the body.


Visceral artery aneurysms include those isolated to the  renal artery ,  splenic artery ,  celiac artery , and  hepatic artery . Of these, data shows that splenic artery aneurysms are the most common. [ 10 ]


Indications for repair differ slightly between arteries. For instance, current guidelines recommend repair of renal and splenic artery aneurysms greater than 3 cm, and those of any size in women of childbearing age; whereas celiac and hepatic artery aneurysms are indicated for repair when their size is greater than 2 cm. This is in contrast to superior mesenteric artery aneurysms which should be repaired regardless of size when they are discovered. [ 11 ]


A  popliteal artery aneurysm  is an arterial aneurysm localized in the  popliteal artery  which courses behind the  knee . Unlike aneurysms located in the abdomen, popliteal artery aneurysm rarely present with rupture but rather with symptoms of  acute limb ischemia  due to embolization of thrombus. Thus, when a patient presents with an asymptomatic popliteal aneurysm that is greater than 2 cm in diameter a vascular surgeon are able to offer vascular bypass or endovascular exclusion depending on several factors. [ 12 ]


The artery wall is composed of three concentric layers: the  intima ,  media  and  adventitia . In general, an  arterial dissection  is a tear in the innermost layer of the arterial wall that makes a separation which allows blood to flow, and collect, between the layers. Arterial dissections include: an  aortic dissection  ( aorta ), a  coronary artery dissection  ( coronary artery ), two types of  cervical artery dissection  involving one of the arteries in the neck – a  carotid artery dissection  ( carotid artery ), and a  vertebral artery dissection  ( vertebral artery ), a pulmonary artery dissection is an extremely rare condition as a complication of chronic  pulmonary hypertension . [ 13 ]


Whereas  cardiac surgeons  are usually in charge of managing type A dissections, type B dissections are typically managed by vascular surgeons. The most common risk factor for type B aortic dissection is  hypertension . The first line treatment for type B aortic dissection is aimed at reducing both  heart rate  and  blood pressure  and is referred to as anti-impulse therapy.


Should initial medical management fail or there is the involvement of a major branch of the aorta, vascular surgery may be needed for these type B dissections. Treatment may include thoracic endovascular aortic repair (TEVAR) with or without extra-anatomic  bypass  such as carotid-carotid bypass, carotid-subclavian bypass, or subclavian-carotid transposition. [ 14 ]


Visceral artery dissections are arterial dissections involving the  superior mesenteric artery ,  celiac artery ,  renal arteries ,  hepatic artery  and others. When they are an extension of an aortic dissection, this condition is managed simultaneously with aortic treatment. In isolation, visceral artery dissections are discovered incidentally in up to a third of patients and in these cases may be managed medically by a vascular surgeon. In cases where the dissection results in organ damage it is generally accepted by vascular surgeons that surgery is necessary. Surgical management strategies depend on the associated complications, surgical ability and patient preference. [ 15 ] [ 16 ]


Mesenteric ischemia results from the acute or chronic obstruction of the  superior mesenteric artery  (SMA). The SMA arises from the abdominal aorta and usually supplies blood from the distal  duodenum  through two-thirds of the  transverse colon  and the  pancreas .


The symptoms of chronic mesenteric ischemia can be classified as  abdominal angina [ 17 ]  which is abdominal pain which occurs a fixed period of time after eating. Due to this, patient's may avoid eating, resulting in unintended weight loss. The first surgical treatment is thought to be performed by R.S. Shaw and described in the  New England Journal of Medicine  in 1958. The procedure Shaw described is referred to as mesenteric  endarterectomy . [ 18 ]  Since then, many advances in treatment have been made in minimally invasive,  endovascular  techniques including  angioplasty  and stenting.


Acute mesenteric ischemia (AMI) results from the sudden  occlusion  of the  superior mesenteric artery .


The renal arteries supply oxygenated blood to the kidneys. The kidneys serve to filter the flood and control blood pressure through the renin-angiotensin system. One cause of resistant hypertension is atherosclerotic disease in the renal arteries and is generally referred to as  renovascular hypertension . If renovascular hypertension is diagnosed and maximal medical fails to control high blood pressure, the vascular surgeon may offer surgical treatment, either endovascular or open surgical reconstruction.


Vascular surgeons are responsible for treating extracranial cerebrovascular disease as well as the interpretation of non-invasive vascular imaging relating to extracranial and intracranial circulation such as  carotid ultrasonography  and  transcranial doppler . The most common of cerebrovascular conditions treated by vascular surgeons is  carotid artery stenosis  which is a narrowing of the  carotid arteries  and may be either clinically symptomatic or asymptomatic (silent). Carotid artery stenosis is caused by  atherosclerosis  whereby the buildup of  atheromatous plaque  inside the artery causes narrowing.


Symptoms of carotid artery stenosis can include  transient ischemic attack  or  stroke . Both symptomatic and asymptomatic carotid stenosis can be diagnosed with the aid of carotid duplex ultrasound which allows for the estimation of severity of narrowing as well as characterize the plaque. Treatment can include medical therapy,  carotid endarterectomy  or  carotid stenting .


The  Society for Vascular Surgery  publishes clinical practice guidelines for the management of extracranial cerebrovascular disease. [ 19 ]  Less common diseases involving cerebral circulation treated by vascular surgeons include  vertebrobasilar insufficiency ,  subclavian steal syndrome ,  carotid artery dissection ,  vertebral artery dissection ,  carotid body tumor  and carotid artery aneurysm among others.


Peripheral artery disease  PAD is the abnormal narrowing of the arteries which supply the limbs. Patients with this condition can present with  intermittent claudication  which is pain mainly in the calves and thighs while walking. If there is progression, a patient may also present with  chronic limb threatening ischemia  which encompasses pain at rest and non-healing wounds. Vascular surgeons are experts in the diagnosis, medical management, endovascular and open surgical treatment of PAD. [ 20 ]


A vascular surgeon may diagnose PAD using a combination of  history ,  physical exam  and  medical imaging . Medical imaging may include  ankle-brachial index ,  doppler ultrasonography  and  computed tomography angiography , among others. Treatments are individualized and may include medical therapy, endovascular intervention or open surgical options including  angioplasty ,  stenting ,  atherectomy ,  endarterectomy  and  vascular bypass , among others.


Chronic venous insufficiency  is the abnormal pooling of blood in the lower extremity venous system which can lead to reticular veins, varicose veins, chronic edema and inflammation among other things. Population data suggests that chronic venous insufficiency affects up to 40% of females and 17% of males. [ 21 ]  When chronic insufficiency leads to pain, swelling and skin changes it is referred to as  chronic venous disease . Chronic venous insufficiency (CVI) is distinguished from  post-thrombotic syndrome  (PTS) in that CVI is primarily an issue of valvular incompetence of the  superficial  or  deep veins  whereas PTS may occur as a long-term complication of  deep venous thrombosis . [ 22 ]


The vascular surgeon has several modalities to treat lower extremity venous disease which including medical, interventional and surgical procedures. For instance, venous ulceration may be treated with  Unna's boots , superficial venous reflux with  radiofrequency ,  laser ablation  or  vein stripping  if indicated. When indicated, insufficiency in the deep veins may be treated with reconstruction of the venous valves with internal or external valvuloplasty. [ 23 ]


Lower extremity  varicose veins  is the condition in which the  superficial veins  become tortuous (snakelike) and dilated (enlarged) to greater than 3 mm (0.12 in) in the upright position. [ 24 ]  Incompetent or faulty valves are often present in these veins when investigated with  duplex ultrasonography . Vascular treatments can include  compression stockings , venous ablation or  vein stripping , depending on specific patient presentation, severity of disease, among other things.


Nonthrombotic iliac vein lesions (NIVL) include  May-Thurner Syndrome  (MTS) whereby there is compression of the left iliac venous outflow usually by the right iliac artery leading to left leg discomfort, pain, swelling and varicose veins. NIVL encompasses compression of the iliac veins on either the right or left side. [ 25 ]  Vascular surgeons may offer different treatment modalities depending on the patient presentation. Minimally invasive diagnostic and therapeutic options might include  intravascular ultrasound , venography and iliac vein stenting whereas surgical management may be offered in refractory cases. [ 26 ]  Surgical management strategies involve reconstruction or bypass of the affected segment such as cross-pubic venous bypass, also known as the Palma procedure. [ 27 ] [ 28 ]


Deep vein thrombosis  (DVT) is the formation of thrombus in a  deep vein . DVT is more likely to occur in the lower extremity than the upper extremity or  jugular vein . When a DVT involves the pelvic and lower extremity veins it can sometimes be classified as an  iliofemoral DVT . Some evidence to suggests that performing an intervention in these cases may be beneficial whereas other evidence does not. [ 29 ]  Overall, the data shows that there may be a reduction in the incidence in  post-thrombotic syndrome  in patients who undergo certain procedures for iliofemoral DVT but it is not without risks. [ 30 ]  A vascular surgeon may offer venogram, endovascular suction or mechanical thrombectomy and in some cases pharmacomechanical thrombectomy. [ citation needed ]  Some lower extremity DVT can be severe enough to cause a condition called  phlegmasia cerulea dolens  or  phlegmasia alba dolens  and can be limb-threatening events. When phlegmasia is present, intervention is often warranted and may include venous thrombectomy.


Post-thrombotic syndrome  (PTS) is a medical condition that sometimes occurs as a long-term complication of DVT and is characterized by long term  edema  and skin changes following DVT. Presenting symptoms may include itchiness, pain, cramps and paresthesia. It is estimated that between 20% and 50% of patients will experience some degree of PTS. [ 31 ]  A treatment strategy for PTS may involve the use of compression stockings.


Surgical management of an acute  pulmonary embolism  ( pulmonary thrombectomy ) is uncommon and has largely been abandoned because of poor long-term outcomes. However, recently, it has gone through a resurgence with the revision of the surgical technique and is thought to benefit certain people. [ 32 ]  Chronic pulmonary embolism leading to  pulmonary hypertension  (known as  chronic thromboembolic hypertension ) is treated with a surgical procedure known as a  pulmonary thromboendarterectomy . [ 33 ]


Compression of large veins by adjacent structures or masses may lead to distinct  clinical syndromes  including  May–Thurner syndrome  (MTS),  nutcracker syndrome  and  superior vena cava syndrome  to name a few. Treatment modalities include  venography ,  intravascular ultrasound  and venous  stenting  as well as more invasive open venous reconstruction and bypass.


Patients with  chronic kidney disease  may have progression of disease which requires  renal replacement therapy  to filter their blood. One strategy for this therapy is  hemodialysis , which is a procedure that involves filtering a patient's blood to remove waste products and returning their blood back to them. One method which avoids repeated arterial trauma is to create an  arteriovenous fistula  (AVF). The first procedure described for this purpose is named the  Cimino fistula , after one of the surgeons who first had success with it. Vascular surgeons may create an AVF for a patient as well as undertake minimally invasive procedures to ensure the fistula remains  patent .


One way that vascular trauma may be understood is by categorizing vascular injury by three criteria: mechanism of injury, anatomical site of injury and contextual circumstances. Mechanism of injury refers to etiology, e.g.  iatrogenic ,  blunt ,  penetrating ,  blast injury , etc. Anatomical site functionally refers to whether there is compressible versus non-compressible hemorrhage, while contextual circumstances refers to injuries sustained in the civilian or military realm. Each context can be further broken down: military into combatant vs. noncombatant and civil into urban vs rural trauma. [ 34 ]  This categorization scheme is of both epidemiologic and clinical significance. For instance, arterial injury in military combatants currently occurs predominantly in males in their twenties who are exposed to improvised explosive devices or gunshot wounds; whereas in the civilian realm, one study conducted in the United States showed the most common mechanisms to include motor vehicle collisions, firearm injuries, stab wounds and falls from heights. [ 35 ]


Advances in vascular surgery, specifically endovascular technologies, have led to a dramatic change in the operative approach to  blunt thoracic aortic injury  (BTAI). BTAI results from a high speed insult to the thorax such as a  motor vehicle collision  or a fall from a height. One widely-used classification scheme is based on the extent of injury to the anatomic layers of the aorta as seen with  computed tomography angiography  or  intravascular ultrasound . Grade 1 BTAI are those which tear the aortic intima; grade 2 injuries refer to intramural hematoma; grade 3 injuries are pseudoaneurysm and are only contained by adventitial tissue; and grade 4 refer to free rupture of blood into the chest and surrounding tissue. [ 36 ]  When indicated, first line intervention involves  TEVAR .


Previously considered a field within  general surgery , it is now considered a specialty in its own right. As a result, there are two pathways for training in the United States. Traditionally, a five-year general surgery residency is followed by a 1-2 year (typically 2 years) vascular surgery fellowship. An alternative path is to perform a five or six year vascular surgery residency. In many countries, Vascular surgeons can opt for additional training in  cardiac surgery  as well as post-residency.


Programs of training vary slightly between different regions of the world.


Abdominal aortic aneurysm  ( AAA ) is a localized enlargement of the  abdominal aorta  such that the diameter is greater than 3 cm or more than 50% larger than normal. [ 1 ]  An AAA usually causes no symptoms, except during rupture. [ 1 ]  Occasionally, abdominal, back, or leg pain may occur. [ 2 ]  Large aneurysms can sometimes be felt by pushing on the abdomen. [ 2 ]   Rupture  may result in pain in the abdomen or back,  low blood pressure , or  loss of consciousness , and often results in death. [ 1 ] [ 6 ]


AAAs occur most commonly in men, those over 50 and those with a family history of the disease. [ 1 ]  Additional risk factors include  smoking ,  high blood pressure , and other  heart or blood vessel diseases . [ 3 ]  Genetic conditions with an increased risk include  Marfan syndrome  and  Ehlers–Danlos syndrome . [ 4 ]  AAAs are the most common form of  aortic aneurysm . [ 4 ]  About 85% occur below the  kidneys , with the rest either at the level of or above the kidneys. [ 1 ]  In the  United States ,  screening  with  abdominal ultrasound  is recommended for males between 65 and 75 years of age with a history of smoking. [ 7 ]  In the  United Kingdom  and  Sweden , screening all men over 65 is recommended. [ 1 ] [ 8 ]  Once an aneurysm is found, further ultrasounds are typically done on a regular basis until an aneurysm meets a threshold for repair. [ 2 ]


Abstinence from cigarette smoking is the single best way to prevent the disease. [ 1 ]  Other methods of prevention include treating high blood pressure, treating  high blood cholesterol , and avoiding being  overweight . [ 1 ]  Surgery is usually recommended when the diameter of an AAA grows to >5.5 cm in males and >5.0 cm in females. [ 1 ]  Other reasons for repair include the presence of symptoms and a rapid increase in size, defined as more than one centimeter per year. [ 2 ]  Repair may be either by  open surgery  or  endovascular aneurysm repair  (EVAR). [ 1 ]  As compared to open surgery, EVAR has a lower risk of death in the short term and a shorter hospital stay, but may not always be an option. [ 1 ] [ 9 ] [ 10 ]  There does not appear to be a difference in longer-term outcomes between the two. [ 11 ]  Repeat procedures are more common with EVAR. [ 12 ]


AAAs affect 2-8% of males over the age of 65. [ 1 ]  They are five times more common in men. [ 13 ]  In those with an aneurysm less than 5.5 cm, the risk of rupture in the next year is below 1%. [ 1 ]  Among those with an aneurysm between 5.5 and 7 cm, the risk is about 10%, while for those with an aneurysm greater than 7 cm the risk is about 33%. [ 1 ]   Mortality  if ruptured is 85% to 90%. [ 1 ]  Globally, aortic aneurysms resulted in 168,200 deaths in 2013, up from 100,000 in 1990. [ 5 ] [ 14 ]  In the United States AAAs resulted in between 10,000 and 18,000 deaths in 2009. [ 4 ]


The vast majority of aneurysms are asymptomatic. However, as the abdominal aorta expands and/or ruptures, the aneurysm may become painful and lead to pulsating sensations in the abdomen or pain in the chest, lower back, legs, or scrotum. [ 15 ]


The complications include rupture, peripheral  embolization , acute aortic occlusion, and aortocaval (between the aorta and  inferior vena cava ) or aortoduodenal (between the aorta and the  duodenum )  fistulae . On physical examination, a  palpable  and pulsatile abdominal mass can be noted.  Bruits  can be present in case of renal or visceral arterial  stenosis . [ 16 ]


The signs and symptoms of a ruptured AAA may include severe pain in the lower back, flank, abdomen or groin. A mass that pulses with the heart beat may also be felt. [ 6 ]  The bleeding can lead to a  hypovolemic shock  with  low blood pressure  and a  fast heart rate , which may cause  fainting . [ 6 ]  The mortality of AAA rupture is as high as 90 percent. 65 to 75 percent of patients die before they arrive at the hospital and up to 90 percent die before they reach the operating room. [ 17 ]  The bleeding can be  retroperitoneal  or into the  abdominal cavity . Rupture can also create a connection between the aorta and intestine or  inferior vena cava . [ 18 ]  Flank  ecchymosis  (appearance of a bruise) is a sign of retroperitoneal  bleeding  and is also called  Grey Turner's sign . [ 16 ] [ 19 ]


The exact causes of the degenerative process remain unclear. There are, however, some hypotheses and well-defined  risk factors . [ 20 ]


The most striking  histopathological  changes of the aneurysmatic aorta are seen in the  tunica media  and  intima  layers. These changes include the accumulation of lipids in  foam cells , extracellular free  cholesterol  crystals,  calcifications ,  thrombosis , and  ulcerations  and ruptures of the layers.  Adventitial   inflammatory   infiltrate  is present. [ 18 ]
However, the  degradation  of the tunica media by means of a  proteolytic  process seems to be the basic  pathophysiologic  mechanism of AAA development. Some researchers report increased expression and activity of matrix  metalloproteinases  in individuals with AAA. This leads to elimination of  elastin  from the media, rendering the aortic wall more susceptible to the influence of  blood pressure . [ 16 ]  Other reports have suggested the  serine protease   granzyme B  may contribute to aortic aneurysm rupture through the cleavage of  decorin , leading to disrupted  collagen  organization and reduced tensile strength of the adventitia. [ 26 ] [ 27 ]  There is also a reduced amount of  vasa vasorum  in the abdominal aorta (compared to the thoracic aorta); consequently, the tunica media must rely mostly on diffusion for nutrition, which makes it more susceptible to damage. [ 28 ]


Hemodynamics  affect the development of AAA, which has a  predilection  for the  infrarenal  aorta. The histological structure and mechanical characteristics of the infrarenal aorta differ from those of the  thoracic aorta . The diameter decreases from the root to the  aortic bifurcation , and the wall of the infrarenal aorta also contains a lesser proportion of  elastin . The mechanical  tension  in the abdominal aortic wall is therefore higher than in the thoracic aortic wall. The  elasticity  and  distensibility  also decline with age, which can result in gradual  dilatation  of the segment. Higher  intraluminal  pressure in patients with arterial hypertension markedly contributes to the progression of the pathological process. [ 18 ]  Suitable hemodynamic conditions may be linked to specific intraluminal thrombus (ILT) patterns along the aortic lumen, which in turn may affect AAA's development. [ 29 ]


An abdominal aortic aneurysm is usually diagnosed by  physical exam ,  abdominal ultrasound , or  CT scan . Plain abdominal radiographs may show the outline of an aneurysm when its walls are calcified. However, the outline will be visible by X-ray in less than half of all aneurysms. Ultrasonography is used to screen for aneurysms and to determine their size if present. Additionally, free peritoneal fluid can be detected. It is noninvasive and sensitive, but the presence of bowel gas or obesity may limit its usefulness. [ 30 ]  CT scan has nearly 100% sensitivity for an aneurysm and is also useful in preoperative planning, detailing the anatomy and possibility for endovascular repair. In the case of suspected rupture, it can also reliably detect retroperitoneal fluid. Alternative less often used methods for visualization of an aneurysm include  MRI  and  angiography . [ 31 ]


An aneurysm ruptures if the mechanical stress (tension per area) exceeds the local wall strength; consequently, peak wall stress (PWS), [ 32 ]  mean wall stress (MWS), [ 33 ]  and peak wall rupture risk (PWRR) [ 34 ]  have been found to be more reliable parameters than diameter to assess AAA rupture risk. Medical software allows computing these rupture risk indices from standard clinical CT data and provides a patient-specific AAA rupture risk diagnosis. [ 35 ] [ 36 ] [ 37 ]  This type of biomechanical approach has been shown to accurately predict the location of AAA rupture. [ 36 ] [ 37 ] [ 38 ]


Abdominal aortic aneurysms are commonly divided according to their size and symptomatology. An aneurysm is usually defined as an outer aortic diameter over 3 cm (normal diameter of the  aorta  is around 2 cm), [ 43 ]  or more than 50% of normal diameter. [ 44 ]  If the outer diameter exceeds 5.5 cm, the aneurysm is considered to be large. [ 42 ]  Ruptured AAA should be suspected in any person older than 60 who experiences collapse, unexplained low blood pressure, or sudden-onset back or abdominal pain. Abdominal pain, shock, and a pulsatile mass is only present in a minority of cases. [ citation needed ]  Although an unstable person with a known aneurysm may undergo surgery without further imaging, the diagnosis will usually be confirmed using CT or ultrasound scanning. [ citation needed ]


The suprarenal aorta normally measures about 0.5 cm larger than the infrarenal aorta. [ 45 ]


Aortic aneurysm rupture may be mistaken for the  pain of kidney stones , or muscle related  back pain . [ 6 ]


In terms of prevention we find the following: [ citation needed ]


The  U.S. Preventive Services Task Force  (USPSTF) recommends a single screening  abdominal ultrasound  for abdominal aortic aneurysm in males age 65 to 75 years who have a history of smoking. [ 46 ]  Among this group who does not smoke, screening may be selective. [ 46 ]  It is unclear if screening is useful in women who have smoked and the USPSTF recommend against screening in women who have never smoked. [ 7 ] [ 47 ]


In the United Kingdom the NHS AAA Screening Programme invites men in England for screening during the year they turn 65. Men over 65 can contact the programme to arrange to be screened. [ 48 ]


In Sweden one time screening is recommended in all males over 65 years of age. [ 1 ] [ 8 ]  This has been found to decrease the risk of death from AAA by 42% with a number needed to screen of just over 200. [ 47 ]  In those with a close relative diagnosed with an aortic aneurysm, Swedish guidelines recommend an ultrasound at around 60 years of age. [ 49 ]


Australia has no guideline on screening. [ 50 ]


Repeat ultrasounds should be carried out in those who have an aortic size greater than 3.0 cm. [ 51 ]  In those whose aorta is between 3.0 and 3.9 cm this should be every three years, if between 4.0 and 4.4 cm every two years, and if between 4.5 and 5.4 cm every year. [ 51 ]


The treatment options for asymptomatic AAA are  conservative  management, surveillance with a view to eventual repair, and immediate repair. Two modes of repair are available for an AAA:  open aneurysm repair , and endovascular aneurysm repair ( EVAR ). An intervention is often recommended if the aneurysm grows more than 1 cm per year or it is bigger than 5.5 cm. [ 52 ]  Repair is also indicated for symptomatic aneurysms. Ten years after open AAA repair, the overall survival rate was 59%. [ 53 ]  Mycotic abdominal aorta aneurysm (MAAA) is a rare and life-threatening condition. Because of its rarity, there is a lack of adequately powered studies and consensus on its treatment and follow up. A management protocol on the management of mycotic abdominal aortic aneurysm was recently published in the Annals of Vascular Surgery by Premnath et al. [ 54 ]


Conservative management is indicated in people where repair carries a high risk of mortality and in patients where repair is unlikely to improve life expectancy. The mainstay of the conservative treatment is  smoking  cessation. [ citation needed ]


Surveillance is indicated in small asymptomatic aneurysms (less than 5.5 cm) where the risk of repair exceeds the risk of rupture. [ 52 ]  As an AAA grows in diameter, the risk of rupture increases. Surveillance until an aneurysm has reached a diameter of 5.5 cm has not been shown to have a higher risk as compared to early intervention. [ 55 ] [ 56 ]


No medical therapy has been found to be effective at decreasing the growth rate or rupture rate of asymptomatic AAAs. [ 1 ]   Blood pressure  and  lipids  should, however, be treated per usual. [ 43 ]


The threshold for repair varies slightly from individual to individual, depending on the balance of risks and benefits when considering repair versus ongoing surveillance. The size of an individual's native aorta may influence this, along with the presence of comorbidities that increase operative risk or decrease life expectancy. Evidence, however, does not usually support repair if the size is less than 5.5 cm. [ 52 ]


Open repair is indicated in young patients as an elective procedure, or in growing or large, symptomatic or ruptured aneurysms. The aorta must be clamped during the repair, denying blood to the abdominal organs and sections of the  spinal cord ; this can cause a range of complications. As it is essential to perform the critical part of the operation quickly, the incision is typically made large enough to facilitate the fastest repair. Recovery after open AAA surgery takes significant time. The minimums are a few days in intensive care, a week total in the hospital and a few months before full recovery. [ citation needed ]


Endovascular repair first became practical in the 1990s and although it is now an established alternative to open repair, its role is yet to be clearly defined. It is generally indicated in older, high-risk patients or patients unfit for open repair. However, endovascular repair is feasible for only a portion of AAAs, depending on the morphology of the aneurysm. The main advantages over open repair are that there is less peri-operative mortality, less time in  intensive care , less time in hospital overall and earlier return to normal activity. Disadvantages of endovascular repair include a requirement for more frequent ongoing hospital reviews and a higher chance of further required procedures. According to the latest studies, the EVAR procedure does not offer any benefit for overall survival or health-related  quality of life  compared to open surgery, although aneurysm-related mortality is lower. [ 57 ] [ 58 ] [ 59 ] [ 60 ]  In patients unfit for open repair, EVAR plus conservative management was associated with no benefit, more complications, subsequent procedures and higher costs compared to conservative management alone. [ 61 ]  Endovascular treatment for paraanastomotic aneurysms after aortobiiliac reconstruction is also a possibility. [ 62 ]  A 2017  Cochrane review  found tentative evidence of no difference in outcomes between endovascular and open repair of ruptured AAA in the first month. [ 63 ]


In those with  aortic rupture  of the AAA, treatment is immediate surgical repair. There appear to be benefits to allowing  permissive hypotension  and limiting the use of intravenous fluids during transport to the operating room. [ 64 ]


Although the current standard of determining rupture risk is based on maximum diameter, it is known that smaller AAAs that fall below this threshold (diameter<5.5 cm) may also rupture, and larger AAAs (diameter>5.5 cm) may remain stable. [ 67 ] [ 68 ]  In one report, it was shown that 10–24% of ruptured AAAs were less than 5 cm in diameter. [ 68 ]  It has also been reported that of 473 non-repaired AAAs examined from autopsy reports, there were 118 cases of rupture, 13% of which were less than 5 cm in diameter. This study also showed that 60% of the AAAs greater than 5 cm (including 54% of those AAAs between 7.1 and 10 cm) never experienced rupture. [ 69 ]  Vorp  et al.  later deduced from the findings of Darling  et al.  that if the maximum diameter criterion were followed for the 473 subjects, only 7% (34/473) of cases would have died from rupture prior to surgical intervention as the diameter was less than 5 cm, with 25% (116/473) of cases possibly undergoing unnecessary surgery since these AAAs may never have ruptured. [ 69 ]


Alternative methods of rupture assessment have been recently reported. The majority of these approaches involve the numerical analysis of AAAs using the common engineering technique of the finite element method (FEM) to determine the wall stress distributions. Recent reports have shown that these stress distributions have been shown to correlate to the overall geometry of the AAA rather than solely to the maximum diameter. [ 70 ] [ 71 ] [ 72 ]  It is also known that wall stress alone does not completely govern failure as an AAA will usually rupture when the wall stress exceeds the wall strength. In light of this, rupture assessment may be more accurate if both the patient-specific wall stress is coupled together with patient-specific wall strength. A noninvasive method of determining patient-dependent wall strength was recently reported, [ 73 ]  with more traditional approaches to strength determination via tensile testing performed by other researchers in the field. [ 74 ] [ 75 ] [ 76 ]  Some of the more recently proposed AAA rupture-risk assessment methods include: AAA wall stress; [ 32 ] [ 77 ] [ 78 ]  AAA expansion rate; [ 79 ]  degree of asymmetry; [ 72 ]  presence of intraluminal thrombus (ILT); [ 80 ]  a rupture potential index (RPI); [ 81 ] [ 82 ]  a finite element analysis rupture index (FEARI); [ 83 ]  biomechanical factors coupled with computer analysis; [ 84 ]  growth of ILT; [ 85 ]  geometrical parameters of the AAA; [ 86 ]  and also a method of determining AAA growth and rupture based on mathematical models. [ 87 ] [ 88 ]


The postoperative mortality for an already ruptured AAA has slowly decreased over several decades but remains higher than 40%. [ 89 ]  However, if the AAA is surgically repaired before rupture, the postoperative mortality rate is substantially lower, approximately 1-6%. [ 90 ]


The occurrence of AAA varies by ethnicity. In the United Kingdom, the rate of AAA in Caucasian men older than 65 years is about 4.7%, while in Asian men it is 0.45%. [ 91 ]  It is also less common in individuals of African, and Hispanic heritage. [ 1 ]  They occur four times more often in men than in women. [ 1 ]


There are at least 13,000 deaths yearly in the U.S. secondary to AAA rupture. [ 1 ]  The peak  number of new cases per year  among males is around 70 years of age, and the  percentage of males affected  over 60 years is 2–6%. The frequency is much higher in smokers than in non-smokers (8:1), and the risk decreases slowly after  smoking cessation . [ 92 ]  In the U.S., the incidence of AAA is 2–4% in the adult population. [ 16 ]


Rupture of the AAA occurs in 1–3% of men aged 65 or more, for whom the mortality rate is 70–95%. [ 42 ]


The first historical records about AAA are from  Ancient Rome  in the 2nd century AD, when Greek surgeon  Antyllus  tried to treat the AAA with  proximal  and  distal   ligature , central  incision  and removal of  thrombotic  material from the  aneurysm .
However, attempts to treat the AAA surgically were unsuccessful until 1923. In that year,  Rudolph Matas  (who also proposed the concept of endoaneurysmorrhaphy), performed the first successful aortic ligation on a human. [ 93 ]  Other methods that were successful in treating the AAA included wrapping the aorta with polyethene  cellophane , which induced  fibrosis  and restricted the growth of the aneurysm. Endovascular aneurysm repair was first performed in the late 1980s and has been widely adopted in the subsequent decades. Endovascular repair was first used for treating a ruptured aneurysm in Nottingham in 1994. [ 94 ]


Theoretical physicist  Albert Einstein  underwent an operation for an abdominal aortic aneurysm in 1949 that was performed by  Rudolph Nissen , who wrapped the aorta with polyethene  cellophane . Einstein's aneurysm ruptured on April 13, 1955. He declined surgery, saying, "I want to go when I want. It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly." He died five days later at age 76. [ 95 ]


Actress  Lucille Ball  died April 26, 1989, from an abdominal aortic aneurysm. At the time of her death, she was in  Cedars-Sinai Medical Center  recovering from emergency surgery performed just six days earlier because of a  dissecting aortic aneurysm  near her heart. Ball was at increased risk as she had been a heavy smoker for decades. [ 96 ]


Musician  Conway Twitty  died in June 1993 from an abdominal aortic aneurysm at the age of 59, two months before the release of what would be his final studio album,  Final Touches . [ citation needed ]


Actor  George C. Scott  died in 1999, aged 71, from a ruptured abdominal aortic aneurysm. [ citation needed ]


In 2001, former presidential candidate  Bob Dole  underwent surgery for an abdominal aortic aneurysm in which a team led by  vascular surgeon   Kenneth Ouriel  inserted a stent graft: [ 97 ]


Ouriel said that the team inserted a Y-shaped tube through an incision in Dole's leg and placed it inside the weakened portion of the aorta. The aneurysm will eventually contract around the stent, which will remain in place for the rest of Dole's life. [ 97 ]


—  Associated Press


Actor  Robert Jacks , who played  Leatherface  in  Texas Chainsaw Massacre: The Next Generation , died from an abdominal aneurysm on August 8, 2001, one day shy of his 42nd birthday. When Jacks was a child, his father died from the same cause.


Actor  Tommy Ford  died of abdominal aneurysm in October 2016 at 52 years old. [ 98 ]


Gary Gygax , co-creator of  Dungeons & Dragons , died from an abdominal aortic aneurysm in 2008, at the age of 69.


Harvey Korman  died on May 29, 2008, aged 81, at UCLA Medical Center as the result of complications from a ruptured abdominal aortic aneurysm he had suffered four months earlier. He is interred at Santa Monica's Woodlawn Cemetery.


John Ritter  died from AAA on September 11, 2003. He was initially treated by emergency room physicians for a heart attack; however, his condition quickly worsened. He was then diagnosed with aortic dissection and was taken into surgery, but was pronounced dead at 10:48 p.m., at the age of 54.


There have been many calls for alternative approaches to rupture risk assessment over the past number of years, with many believing that a biomechanics-based approach may be more suitable than the current diameter approach. Numerical modeling is a valuable tool to researchers allowing approximate wall stresses to be calculated, thus revealing the rupture potential of a particular aneurysm. Experimental models are required to validate these numerical results and provide a further insight into the biomechanical behavior of the AAA.  In vivo , AAAs exhibit a varying range of material strengths [ 99 ]  from localised weak hypoxic regions [ 100 ]  to much stronger regions and areas of calcifications. [ 101 ]


Finding ways to predict future AAA growth is seen as a research priority. [ 102 ]


Another related line of research is utilizing mathematical decision modeling (e.g.,  Markov decision processes ) to determine improved treatment policies. Initial results suggest that a more dynamic policy could provide benefits, although such claims have not been clinically verified. [ 103 ] [ 104 ]  A study recently showed that aneurysms can be accurately predicted as to whether they are stable (lacking repair or intervention), requiring repair, or at risk of rupture from scans years prior to any event based on a machine-learning based classification tool. [ 105 ]


Experimental models can now be manufactured using a novel technique involving the injection-moulding lost-wax manufacturing process to create patient-specific anatomically correct AAA replicas. [ 106 ]  Work has also focused on developing more realistic material analogues to those  in vivo , and recently a novel range of silicone-rubbers was created allowing the varying material properties of the AAA to be more accurately represented. [ 107 ]  These rubber models can also be used in a variety of experimental situations, from stress analysis using the photoelastic method [ 108 ]  New endovascular devices are being developed that are able to treat more complex and  tortuous  anatomies. [ 109 ]


An animal study showed that removing a single protein prevents early damage in blood vessels from triggering a later-stage, complications. By eliminating the gene for a signaling protein called cyclophilin A (CypA) from a strain of mice, researchers were able to provide complete protection against abdominal aortic aneurysm. [ 110 ]


Other recent research identified Granzyme B ( GZMB ) (a protein-degrading enzyme) to be a potential target in the treatment of abdominal aortic aneurysms. Elimination of this enzyme in mice models both slowed the progression of aneurysms and improved survival. [ 111 ] [ 112 ]


The mechanisms that lead to AAA development are still not completely understood at a cellular and molecular level. In order to better understand the pathophysiology of AAA, it is often necessary to use experimental animal models. It is often questioned how well do these models translate to human disease. Even though there is no animal model that exactly represents the human condition, all the existing ones focus on one different pathophysiological aspect of the disease. Combining the results from different animal models with clinical research can provide a better overview of the AAA pathophysiology. The most common animal models are rodents (mice and rats), although for certain studies, such as testing preclinical devices or surgical procedures, large animal models (pig, sheep) are more frequently used. The rodent models of AAA can be classified according to different aspects. There are dissecting models vs non-dissecting models and genetically determined models vs chemically induced models. The most commonly used models are the angiotensin-II infusion into ApoE knockout mice (dissecting model, chemically induced), the calcium chloride model (non-dissecting, chemically induced) and the elastase model (non-dissecting, chemically induced model). [ 113 ] [ 114 ]  A recent study has shown that β-Aminopropionitrile plus elastase application to abdominal aorta causes more severe aneurysm in mice as compared to elastase alone. [ 115 ]


An  aortic aneurysm  is an enlargement (dilatation) of the  aorta  to greater than 1.5 times normal size. [ 1 ]  Typically, there are no symptoms except when the  aneurysm   dissects  or  ruptures , which causes sudden, severe pain in the abdomen and lower back. [ 2 ] [ 3 ]


The  etiology  remains an area of active research. Known causes include trauma, infection, and  inflammatory disorders . Risk factors include cigarette smoking, extreme  alcoholism , advanced age,  dyslipidemia ,  hypertension , and  coronary artery disease . [ 4 ]  The pathophysiology of the disease is related to an initial arterial insult causing a cascade of inflammation and extracellular matrix protein breakdown by  proteinases  leading to arterial wall weakening. [ 5 ]  They are most commonly located in the  abdominal aorta , but can also be located in the  thoracic aorta .


Aortic aneurysms result from a weakness in the wall of the aorta and increase the risk of  aortic rupture . When rupture occurs, massive internal  bleeding  results and, unless treated immediately,  shock  and death can occur. One review stated that up to 81% of people having abdominal aortic aneurysm rupture will die, with 32% dying before reaching a hospital. [ 6 ]


According to a review of global data through 2019, the prevalence of  abdominal aortic aneurysm  worldwide was about 0.9% in people under age 79 years, and is about four times higher in men than in women at any age. [ 4 ]  Death occurs in about 55-64% of people having rupture of the AAA. [ 4 ]


Screening with  ultrasound  is indicated in those at high risk. Prevention is by decreasing risk factors, such as  smoking , and treatment is either by open or  endovascular surgery . Aortic aneurysms resulted in about 152,000 deaths worldwide in 2013, up from 100,000 in 1990. [ 7 ]


Aortic aneurysms are classified by their location on the aorta.


Most intact aortic aneurysms do not produce symptoms. As they enlarge, symptoms such as  abdominal pain  and  back pain  may develop. Compression of nerve roots may cause leg pain or numbness. Untreated, aneurysms tend to become progressively larger, although the rate of enlargement is unpredictable for any individual. Rarely, clotted blood which lines most aortic aneurysms can break off and result in an  embolus . [ 8 ]


Aneurysms cannot be found on physical examination. Medical imaging is necessary to confirm the diagnosis and to determine the anatomic extent of the aneurysm. In people presenting with aneurysm of the arch of the aorta, a common sign is a hoarse voice from stretching of the left  recurrent laryngeal nerve , a branch of the vagus nerve that winds around the aortic arch to supply the muscles of the  larynx . [ 10 ]


Abdominal aortic aneurysms (AAAs) are more common than their thoracic counterpart. One reason for this is that  elastin , the principal load-bearing protein present in the wall of the aorta, is reduced in the abdominal aorta as compared to the thoracic aorta. Another is that the abdominal aorta does not possess  vasa vasorum , the nutrient-supplying blood vessels within the wall of the aorta. Most AAA are  true aneurysms  that involve all three layers ( tunica intima ,  tunica media  and  tunica adventitia ). The prevalence of AAAs increases with age, with an average age of 65–70 at the time of diagnosis. AAAs have been attributed to  atherosclerosis , though other factors are involved in their formation. [ 8 ]  Risk factors for AAA include the male gender, aging, a history of smoking,  hypercholesterolemia , and hypertension. [ 4 ] [ 8 ] [ 11 ]  Reviews reported estimates for prevalence rates of AAA were 0.9-9% in men and 1–2% in women, where, generally, the incidence of AAA is four times greater in men compared to women at the same age. [ 4 ] [ 8 ]


The risk of rupture of an AAA is related to its diameter; once the aneurysm reaches about 5 cm, the yearly risk of rupture may exceed the risks of surgical repair for an average-risk patient. Rupture risk is also related to shape; so-called "fusiform" (long) aneurysms are considered less rupture-prone than "saccular" (shorter, bulbous) aneurysms, the latter having more wall tension in a particular location in the aneurysm wall. [ 12 ]


The prevalence of AAA worldwide in 2019 was about 0.9% in people under age 79 years, [ 4 ]  whereas a 2014 review reported a range of 2-12%, occurring in about 8% of men more than 65 years of age. [ 13 ]  Men are about four times more likely to have AA compared to women at any age, with death occurring in about 55-64% of people having AAA rupture. [ 4 ]


Before rupture, an AAA may present as a large,  pulsatile  mass above the  umbilicus . A  bruit  may be heard from the turbulent flow in the aneurysm. Rupture may be the first sign of AAA. Once an aneurysm has ruptured, it presents with classic symptoms of abdominal pain which is severe, constant, and radiating to the back. [ 8 ]


The diagnosis of an abdominal aortic aneurysm can be confirmed by the use of  ultrasound . Rupture may be indicated by the presence of free fluid in the abdomen. A contrast-enhanced abdominal  CT scan  is the best test to diagnose an AAA and guide treatment options. [ 14 ]


In 2019, some 170,000 people worldwide died from AAA rupture, with aging, smoking, and hypertension as principal factors. [ 4 ] [ 11 ]  Annual mortality from ruptured aneurysms in the United States is about 15,000. [ 15 ]


An aortic aneurysm can rupture from wall weakness. Aortic rupture is a surgical emergency and has a high mortality even with prompt treatment. Weekend admission for a ruptured aortic aneurysm is associated with increased mortality compared with admission on a weekday, and this is likely due to several factors including a delay in prompt surgical intervention. [ 16 ]


An aortic aneurysm can occur as a result of trauma, infection, or, most commonly, from an intrinsic abnormality in the  elastin  and  collagen  components of the aortic wall. Aortic aneurysm development and progression have been directly associated with a deficiency of elastin as well as a loss of collagen type 1. [ 19 ]  The elastin-to-collagen ratio is also significantly higher in aneurysmal abdominal aortas compared to healthy abdominal aortas. [ 19 ]  While definite genetic abnormalities were identified in true genetic syndromes (Marfan, Elher-Danlos and others) associated with aortic aneurysms, both thoracic and abdominal aortic aneurysms demonstrate a strong genetic component in their aetiology. [ 20 ]


The risk of aneurysm enlargement may be diminished with attention to the patient's blood pressure, smoking and  cholesterol  levels. There have been proposals to introduce  ultrasound scans  as a screening tool for those most at risk: men over the age of 65. [ 21 ] [ 22 ]


Anacetrapib  is a cholesteryl ester transfer protein inhibitor that raises high-density lipoprotein (HDL) cholesterol and reduces low-density lipoprotein (LDL) cholesterol.
Anacetrapib reduces progression of atherosclerosis, mainly by reducing non-HDL-cholesterol, improves lesion stability and adds to the beneficial effects of atorvastatin [ 23 ]
Elevating the amount of HDL cholesterol in the abdominal area of the aortic artery in mice both reduced the size of aneurysms that had already grown and prevented abdominal aortic aneurysms from forming at all. In short, raising HDL cholesterol is beneficial because it induces programmed cell death. The walls of a failing aorta are replaced and strengthened. New lesions should not form at all when using this drug. [ 24 ]


Screening for an aortic aneurysm so that it may be detected and treated prior to rupture is the best way to reduce the overall mortality of the disease. The most cost-efficient screening test is an abdominal aortic ultrasound study. Noting the results of several large, population-based screening trials, the US  Centers for Medicare and Medicaid Services  (CMS) now provides payment for one ultrasound study in all smokers aged 65 years or older ("SAAAVE Act"). [ 25 ]


Surgery (open or endovascular) is the definitive treatment of an aortic aneurysm. Medical therapy is typically reserved for smaller aneurysms or for elderly, frail patients where the risks of surgical repair exceed the risks of non-operative therapy (observation alone).


Medical therapy of aortic aneurysms involves strict  blood pressure  control. This does not treat the aortic aneurysm per se, but control of  hypertension  within tight blood pressure parameters may decrease the rate of expansion of the aneurysm.


The medical management of patients with aortic aneurysms, reserved for smaller aneurysms or frail patients, involves cessation of smoking, blood pressure control, use of  statins  and occasionally  beta blockers . Ultrasound studies are obtained on a regular basis (i.e. every 6 or 12 months) to follow the size of the aneurysm.


Despite optimal medical therapy, patients with large aneurysms are likely to have continued aneurysm growth and risk of aneurysm rupture without surgical repair. [ 26 ]


Decisions about repairing an aortic aneurysm are based on the balance between the risk of aneurysm rupture without treatment versus the risks of the treatment itself. For example, a small aneurysm in an elderly patient with severe  cardiovascular disease  would not be repaired. The chance of the small aneurysm rupturing is overshadowed by the risk of cardiac complications from the procedure to repair the aneurysm.


The risk of the repair procedure is two-fold. First, there is consideration of the risk of problems occurring during and immediately after the procedure itself ("peri-procedural" complications). Second, the effectiveness of the procedure must be taken into account, namely whether the procedure effectively protects the patient from aneurysm rupture over the long term, and whether the procedure is durable so that secondary procedures, with their attendant risks, are not necessary over the life of the patient. A less invasive procedure (such as  endovascular aneurysm repair ) may be associated with fewer short-term risks to the patient (fewer peri-procedural complications) but secondary procedures may be necessary over long-term follow-up.


The determination of surgical intervention is determined on a per-case basis. The diameter of the aneurysm, its rate of growth, the presence or absence of  Marfan syndrome ,  Ehlers–Danlos syndromes  or similar connective tissue disorders, and other  co-morbidities  are all important factors in the overall treatment.


A large, rapidly expanding, or symptomatic aneurysm should be repaired, as it has a greater chance of rupture. Slowly expanding aortic aneurysms may be followed by routine diagnostic testing (i.e.:  CT scan  or  ultrasound  imaging).


For abdominal aneurysms, the current treatment guidelines for abdominal aortic aneurysms suggest elective surgical repair when the diameter of the aneurysm is greater than 5 cm (2 in). However, recent data on patients aged 60–76 suggest medical management for abdominal aneurysms with a diameter of less than 5.5 cm (2 in). [ 27 ]


Open surgery starts with exposure of the dilated portion of the aorta via an incision in the abdomen or abdomen and chest, followed by insertion of a synthetic ( Dacron  or  Gore-Tex ) graft (tube) to replace the diseased aorta. The graft is sewn in by hand to the non-diseased portions of the aorta, and the aneurysmal sac is closed around the graft.


The aorta and its branching arteries are cross-clamped during open surgery. This can lead to inadequate blood supply to the spinal cord, resulting in  paraplegia . A 2004 systematic review and meta analysis found that cerebrospinal fluid drainage (CFSD), when performed in experienced centers, reduces the risk of ischemic spinal cord injury by increasing the perfusion pressure to the spinal cord. [ 28 ]  A 2012 Cochrane systematic review noted that further research regarding the effectiveness of CFSD for preventing a spinal cord injury is required. [ 29 ]  A 2023 systematic review suggested that rates of postoperative spinal cord ischaemia can be kept at low levels after open repair of thoracoabdominal aneurysm with the adequate precautions and perioperative manoeuvres. [ 30 ]  The majority of the surgeons believe prophylactic lumbar drains are effective in reducing spinal cord ischaemia. [ 31 ]  Neuromonitoring with motor-evoked potentials (MEP) can provide the surgeon objective criteria to direct selective intercostal reconstruction or other protective anaesthetic and surgical manoeuvres. Simultaneous monitoring of MEP and somatosensory-evoked potentials (SSEP) seems to be the most reliable method. [ 30 ]


Endovascular treatment of aortic aneurysms  is a minimally invasive alternative to open surgery repair. It involves the placement of an endo-vascular  stent  through small incisions at the top of each leg into the aorta.


As compared to open surgery, EVAR has a lower risk of death in the short term and a shorter hospital stay but may not always be an option. [ 2 ] [ 32 ] [ 33 ]  There does not appear to be a difference in longer term outcomes between the two. [ 34 ]  After EVAR, repeat procedures are more likely to be needed. [ 35 ]


Globally, aortic aneurysms resulted in about ~170,000 deaths in 2017. [ 4 ]  This figure represents an increase from approximately ~100,000 in 1990. [ 7 ]


Aortic dissection  ( AD ) occurs when an injury to the  innermost layer  of the  aorta  allows blood to flow between the layers of the aortic wall,  forcing the layers apart . [ 3 ]  In most cases, this is associated with a sudden onset of agonizing  chest or back pain , often described as "tearing" in character. [ 1 ] [ 2 ]  Vomiting,  sweating , and  lightheadedness  may also occur. [ 2 ]  Damage to other organs may result from the decreased blood supply, such as  stroke , lower extremity ischemia, or  mesenteric ischemia . [ 2 ]  Aortic dissection can quickly lead to death from  insufficient blood flow to the heart  or complete  rupture of the aorta . [ 2 ]


AD is more common in those with a history of  high blood pressure ; a number of  connective tissue diseases  that affect blood vessel wall strength including  Marfan syndrome  and  Ehlers–Danlos syndrome ; a  bicuspid aortic valve ; and previous  heart surgery . [ 2 ] [ 3 ]   Major trauma ,  smoking ,  cocaine  use,  pregnancy , a  thoracic aortic aneurysm ,  inflammation of arteries , and  abnormal lipid levels  are also associated with an increased risk. [ 1 ] [ 2 ]  The diagnosis is suspected based on symptoms with  medical imaging , such as  CT scan ,  MRI , or  ultrasound  used to confirm and further evaluate the dissection. [ 1 ]  The two main types are Stanford type A, which involves the  first part of the aorta , and type B, which does not. [ 1 ]


Prevention is by blood pressure control and smoking cessation. [ 1 ]  Management of AD depends on the part of the aorta involved. [ 1 ]  Dissections that involve the first part of the aorta (adjacent to the heart) usually require surgery. [ 1 ] [ 2 ]  Surgery may be done either by an  opening in the chest  or from  inside the blood vessel . [ 1 ]  Dissections that involve the second part of the aorta can typically be treated with medications that lower blood pressure and heart rate, unless there are complications which then require surgical correction. [ 1 ] [ 2 ]


AD is relatively rare, occurring at an estimated rate of three per 100,000 people per year. [ 1 ] [ 3 ]  It is more common in men than women. [ 1 ]  The typical age at diagnosis is 63, with about 10% of cases occurring before the age of 40. [ 1 ] [ 3 ]  Without treatment, about half of people with Stanford type A dissections die within three days and about 10% of people with Stanford type B dissections die within one month. [ 3 ]  The first case of AD was described in the examination of  King George II of Great Britain  following his death in 1760. [ 3 ]  Surgery for AD was introduced in the 1950s by  Michael E. DeBakey . [ 3 ]


About 96% of individuals with AD present with severe pain that had a sudden onset. The pain may be described as a tearing, stabbing, or sharp sensation in the chest, back, or abdomen. [ 4 ] [ 5 ]  About 17% of individuals feel the pain migrate as the dissection extends down the aorta. [ 6 ]  The location of pain is associated with the location of the dissection. [ 7 ]   Anterior  chest pain is associated with dissections involving the ascending aorta, while interscapular back pain is associated with descending aortic dissections. If the pain is  pleuritic  in nature, it may suggest acute  pericarditis  caused by bleeding into the  sac surrounding the heart . This is a particularly dangerous eventuality, suggesting that acute  pericardial tamponade  may be imminent. Pericardial tamponade is the most common cause of death from AD. [ 8 ]


While the pain may be confused with that of a  heart attack , AD is usually not associated with the other suggestive signs, such as  heart failure  and  ECG  changes. Less common symptoms that may be seen in the setting of AD include  congestive heart failure  (7%),  fainting  (9%),  stroke  (6%), ischemic  peripheral neuropathy ,  paraplegia , and  cardiac arrest . [ 9 ]  If the individual fainted, about half the time it is due to bleeding into the pericardium, leading to pericardial tamponade. Neurological complications of aortic dissection, such as  stroke  and  paralysis , are due to the involvement of one or more arteries supplying portions of the  central nervous system . [ 10 ]


If the AD involves the abdominal aorta, compromise of one or both  renal arteries  occurs in 5–8% of cases, while  ischemia of the intestines  occurs about 3% of the time. [ 11 ] [ 12 ]


People with AD often have a history of  high blood pressure . The blood pressure is quite variable at presentation with acute AD. It tends to be higher in individuals with a distal dissection. In individuals with a proximal AD, 36% present with hypertension, while 25% present with  hypotension . Proximal AD tends to be associated with weakening of the vascular wall due to  cystic medial degeneration . In those who present with distal (Stanford type B) AD, 60–70% present with high blood pressure, while 2–3% present with  low blood pressure . [ 13 ]


Severe hypotension at presentation is a grave prognostic indicator. It is usually associated with pericardial tamponade, severe aortic insufficiency, or rupture of the aorta. Accurate measurement of blood pressure is important. Pseudohypotension (falsely low blood-pressure measurement) may occur due to involvement of the  brachiocephalic artery  (supplying the right arm) or the  left subclavian artery  (supplying the left arm). [ 14 ] [ 15 ]


Aortic insufficiency  (AI) occurs in half to two-thirds of ascending AD, and the diastolic  heart murmur  of aortic insufficiency is audible in about 32% of proximal dissections. The intensity (loudness) of the murmur depends on the blood pressure and may be inaudible in the event of low blood pressure. [ 16 ]