Sterile technique,  aseptic  post-operative care,  antibiotics , use of the  WHO Surgical Safety Checklist , and vigilant post-operative monitoring greatly reduce the risk of these complications.  Planned surgery performed under sterile conditions is much less risky than that performed under emergency or unsterile conditions.  The contents of the bowel are unsterile, and thus leakage of bowel contents, as from trauma, substantially increases the risk of infection.


Globally, there are few studies comparing  perioperative mortality  following abdominal surgery across different health systems. One major prospective study of 10,745 adult patients undergoing emergency  laparotomy  from 357 centres in 58 high-, middle-, and low-income countries found that mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. [ 2 ]  In this study the overall global mortality rate was 1.6 percent at 24 hours (high 1.1 percent, middle 1.9 percent, low 3.4 percent), increasing to 5.4 percent by 30 days (high 4.5 percent, middle 6.0 percent, low 8.6 percent). Of the 578 patients who died, 404 (69.9 percent) did so between 24 hours and 30 days following surgery (high 74.2 percent, middle 68.8 percent, low 60.5 percent). Patient safety factors were suggested to play an important role, with use of the WHO Surgical Safety Checklist associated with reduced mortality at 30 days.


Taking a similar approach, a unique global study of 1,409 children undergoing emergency laparotomy from 253 centres in 43 countries showed that adjusted mortality in children following surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries, translating to 40 excess deaths per 1,000 procedures performed in these settings. Internationally, the most common operations performed were  appendectomy ,  small bowel resection ,  pyloromyotomy  and correction of  intussusception . After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23)) and middle-HDI (4.42 (1.44 to 13.56)) countries compared with high-HDI countries. [ 3 ]


Absorption of drugs administered orally was shown to be significantly affected following abdominal surgery. [ 4 ]


There is low-certainty evidence that there is no difference between using scalpel and  electrosurgery  in infection rates during major abdominal surgeries. [ 5 ]


An  abdomino   perineal   resection , formally known as  abdominoperineal resection of the rectum  and  abdominoperineal excision of the  rectum  is a  surgery  for  rectal cancer  or  anal cancer . It is frequently  abbreviated  as  AP resection ,  APR  and  APER .


See image on National Cancer Institute website
The principal indication for AP resection is a rectal carcinoma situated in the distal (lower) one-third of the rectum. [ 1 ]  Other indications include recurrent or residual anal carcinoma ( squamous cell carcinoma ) following initial, usually definitive combination chemoradiotherapy.


APRs involves removal of the  anus , the  rectum  and part of the  sigmoid colon  along with the associated (regional)  lymph nodes , through incisions made in the  abdomen  and  perineum . The end of the remaining  sigmoid colon  is brought out permanently as an opening, called a  stoma , which is used by the patient in conjunction with a  colostomy  pouch, on the surface of the abdomen.


This operation is one of the less commonly performed by  general surgeons , although they are specifically trained to perform this operation. As low case volumes in rectal surgery have been found to be associated with higher complication rates, [ 2 ] [ 3 ]  it is often centralised in larger centres, [ 4 ]  where case volumes are higher.


There are several advantages in terms of outcomes if the surgery can be performed laparoscopically [ 5 ]


An APR, generally, results in a worse  quality of life  than the less invasive  lower anterior resection  (LAR). [ 6 ] [ 7 ]  Thus, LARs are generally the preferred treatment for rectal cancer insofar as this is surgically feasible.


William Ernest Miles  (1869–1947), an English surgeon first performed the surgery of removing the rectum in 1907. He assumed that the rectal cancer can spread in both upwards and downward directions, thus necessitating the removal of the entire rectum together with the anal sphincters, resulting in a permanent stoma by connecting the proximal end of the descending colon to the skin. Mile's operation became the gold standard for treating rectal cancer because his technique successfully reduced the rate of cancer recurrence. [ 8 ] [ 9 ]


To reduce the incidence of death and suffering of the patients associated with the APR procedure,  Henri Albert Hartmann  introduced the anterior resection of the rectum by preserving the distal rectum and anal sphincters, while producing end-sigmoid colostomy. There were attempts to restore bowel continuity by joining the proximal colon with the rectum, but the high incidence of leakage from the anastomotic site caused an increased risk of death to patients. It was only in 1948, Claude Dixon successfully connected the proximal bowel to the rectum, thus allowing patients to have a 64% 5-year survival rate. [ 8 ]


An  abscess  is a collection of  pus  that has built up within the  tissue  of the body, usually caused by bacterial infection. [ 6 ] [ 7 ]  Signs and symptoms of abscesses include redness, pain, warmth, and swelling. [ 1 ]  The swelling may feel fluid-filled when pressed. [ 1 ]  The area of redness often extends beyond the swelling. [ 8 ]   Carbuncles  and  boils  are types of abscess that often involve  hair follicles , with carbuncles being larger. [ 9 ]  A  cyst  is related to an abscess, but it contains a material other than pus, and a cyst has a clearly defined wall. Abscesses can also form internally on internal organs and after surgery.


They are usually caused by a  bacterial infection . [ 10 ]  Often many different types of bacteria are involved in a single infection. [ 8 ]  In many areas of the world, the most common bacteria present is  methicillin-resistant Staphylococcus aureus . [ 1 ]  Rarely,  parasites  can cause abscesses; this is more common in the  developing world . [ 3 ]  Diagnosis of a skin abscess is usually made based on what it looks like and is confirmed by cutting it open. [ 1 ]   Ultrasound  imaging may be useful in cases in which the diagnosis is not clear. [ 1 ]  In abscesses around the  anus ,  computer tomography  (CT) may be important to look for deeper infection. [ 3 ]


Standard treatment for most skin or soft tissue abscesses is cutting it open and drainage. [ 4 ]  There appears to be some benefit from also using  antibiotics . [ 11 ]  A small amount of evidence supports not packing the cavity that remains with  gauze  after drainage. [ 1 ]  Closing this cavity right after draining it rather than leaving it open may speed healing without increasing the risk of the abscess returning. [ 12 ]  Sucking out the pus with a needle is often not sufficient. [ 1 ]


Skin abscesses are common and have become more common in recent years. [ 1 ]  Risk factors include  intravenous drug use , with rates reported as high as 65% among users. [ 2 ]  In 2005, 3.2 million people went to American emergency departments for abscesses. [ 5 ]  In Australia, around 13,000 people were hospitalized in 2008 with the condition. [ 13 ]


Abscesses may occur in any kind of tissue but most frequently within the skin surface (where they may be superficial pustules known as  boils  or deep skin abscesses), in the  lungs ,  brain ,  teeth , kidneys, and tonsils. Major complications may include spreading of the abscess material to adjacent or remote tissues, and extensive regional tissue death ( gangrene ). [ 14 ]


The main symptoms and signs of a skin abscess are  redness , heat, swelling, pain, and loss of function. There may also be high temperature (fever) and chills. [ 15 ]  If superficial, abscesses may be fluctuant when  palpated ; this wave-like motion is caused by movement of the pus inside the abscess. [ 16 ]


An internal abscess is more difficult to identify and depend on the location of the abscess and the type of infection. General signs include pain in the affected area, a high temperature, and generally feeling unwell. [ 17 ]
Internal abscesses rarely heal themselves, so prompt medical attention is indicated if such an abscess is suspected. An abscess can potentially be fatal depending on where it is located. [ 18 ] [ 19 ]


Risk factors for abscess formation include  intravenous drug use . [ 20 ]  Another possible risk factor is a prior history of disc  herniation  or other spinal abnormality, [ 21 ]  though this has not been proven.


Abscesses are caused by  bacterial infection , parasites, or foreign substances.
Bacterial infection is the most common cause, particularly  Staphylococcus aureus . The more invasive  methicillin-resistant Staphylococcus aureus  (MRSA) may also be a source of infection, though is much rarer. [ 22 ]  Among spinal subdural abscesses, methicillin-sensitive  Staphylococcus aureus  is the most common organism involved. [ 21 ]


Rarely  parasites  can cause abscesses and this is more common in the developing world. [ 3 ]  Specific parasites known to do this include  dracunculiasis  and  myiasis . [ 3 ]


Anorectal abscesses can be caused by non-specific obstruction and ensuing infection of the glandular crypts inside of the  anus  or  rectum . Other causes include  cancer , trauma, or  inflammatory bowel diseases .  [ 23 ]


An  incisional abscess  is one that develops as a complication secondary to a  surgical incision . It presents as redness and warmth at the margins of the incision with purulent drainage from it. [ 24 ]  If the diagnosis is uncertain, the wound should be aspirated with a needle, with aspiration of pus confirming the diagnosis and availing for  Gram stain  and  bacterial culture . [ 24 ]


Abscesses can form inside the body. The cause can be from trauma, surgery, an infection, or a pre-existing condition. [ 17 ]


An abscess is a  defensive reaction  of the tissue to prevent the spread of infectious materials to other parts of the body. [ 25 ] [ 26 ]


Organisms or foreign materials destroy the local  cells , which results in the release of  cytokines . The cytokines trigger an  inflammatory response , which draws large numbers of  white blood cells  to the area and increases the regional blood flow. [ 26 ]


The final structure of the abscess is an abscess wall, or capsule, that is formed by the adjacent healthy cells in an attempt to keep the pus from infecting neighboring structures. However, such encapsulation tends to prevent immune cells from attacking bacteria in the pus, or from reaching the causative organism or foreign object. [ 26 ]


An abscess is a localized collection of pus (purulent inflammatory tissue) caused by suppuration buried in a tissue, an organ, or a confined space, lined by the pyogenic membrane. [ 28 ]   Ultrasound  imaging can help in a diagnosis. [ 29 ]


Abscesses may be classified as either  skin abscesses  or  internal abscesses . Skin abscesses are common; internal abscesses tend to be harder to diagnose, and more serious. [ 15 ]  Skin abscesses are also called cutaneous or subcutaneous abscesses. [ 30 ]


For those with a history of intravenous drug use, an  X-ray  is recommended before treatment to verify that no needle fragments are present. [ 20 ]  If there is also a fever present in this population,  infectious endocarditis  should be considered. [ 20 ]


Abscesses should be differentiated from  empyemas , which are accumulations of pus in a preexisting, rather than a newly formed, anatomical cavity. [ 31 ]


Other conditions that can cause similar symptoms include:  cellulitis , a  sebaceous cyst , and  necrotising fasciitis . [ 3 ]  Cellulitis typically also has an erythematous reaction, but does not confer any purulent drainage. [ 24 ]


The standard treatment for an uncomplicated skin or soft tissue abscess is the act of opening and draining. [ 4 ]  There does not appear to be any benefit from also using  antibiotics  in most cases. [ 1 ]  A small amount of evidence did not find a benefit from packing the abscess with gauze. [ 1 ]


The abscess should be inspected to identify if foreign objects are a cause, which may require their removal. If foreign objects are not the cause, incising and draining the abscess is standard treatment. [ 4 ] [ 32 ]


Most people who have an uncomplicated skin abscess should not use antibiotics. [ 4 ]  Antibiotics in addition to standard incision and drainage is recommended in persons with severe abscesses, many sites of infection, rapid disease progression, the presence of  cellulitis , symptoms indicating bacterial illness throughout the body, or a health condition causing  immunosuppression . [ 1 ]  People who are very young or very old may also need antibiotics. [ 1 ]  If the abscess does not heal only with incision and drainage, or if the abscess is in a place that is difficult to drain such as the face, hands, or genitals, then antibiotics may be indicated. [ 1 ]


In those cases of abscess which do require antibiotic treatment,  Staphylococcus aureus  bacteria is a common cause and an anti-staphylococcus antibiotic such as  flucloxacillin  or  dicloxacillin  is used. The  Infectious Diseases Society of America  advises that the draining of an abscess is not enough to address community-acquired  methicillin-resistant  Staphylococcus aureus  (MRSA), and in those cases, traditional antibiotics may be ineffective. [ 1 ]  Alternative antibiotics effective against community-acquired MRSA often include  clindamycin ,  doxycycline ,  minocycline , and  trimethoprim-sulfamethoxazole . [ 1 ]  The  American College of Emergency Physicians  advises that typical cases of abscess from MRSA get no benefit from having antibiotic treatment in addition to the standard treatment. [ 4 ]


Culturing the wound  is not needed if standard follow-up care can be provided after the incision and drainage. [ 4 ]  Performing a wound culture is unnecessary because it rarely gives information which can be used to guide treatment. [ 4 ]


In North America, after drainage, an abscess cavity is usually packed, often with special iodoform-treated cloth. This is done to absorb and neutralize any remaining exudate as well as to promote draining and prevent premature closure. Prolonged draining is thought to promote healing. The hypothesis is that though the heart's pumping action can deliver immune and regenerative cells to the edge of an injury, an abscess is by definition a void in which no blood vessels are present. Packing is thought to provide a wicking action that continuously draws beneficial factors and cells from the body into the void that must be healed. Discharge is then absorbed by cutaneous bandages and further wicking promoted by changing these bandages regularly. However, evidence from emergency medicine literature reports that packing wounds after draining, especially smaller wounds, causes pain to the person and does not decrease the rate of recurrence, nor bring faster healing, or fewer physician visits. [ 33 ]


More recently, several North American hospitals have opted for less-invasive loop drainage over standard drainage and wound packing. In one study of 143 pediatric outcomes, a failure rate of 1.4% was reported in the loop group versus 10.5% in the packing group (P<.030), [ 34 ]  while a separate study reported a 5.5% failure rate among the loop group. [ 35 ]


Closing an abscess immediately after draining it appears to speed healing without increasing the risk of recurrence. [ 12 ]  This may not apply to anorectal abscesses as while they may heal faster, there may be a higher rate of recurrence than those left open. [ 36 ]


Appendiceal abscess are complications of appendicitis where there is an infected mass on the appendix. This condition is estimated to occur in 2–10% of appendicitis cases and is usually treated by surgical removal of the appendix (appendicectomy). [ 37 ]


Even without treatment, skin abscesses rarely result in death, as they will naturally break through the skin. [ 3 ]  Other types of abscess are more dangerous. Brain abscesses may be fatal if untreated. When treated, the mortality rate reduces to 5–10%, but is higher if the abscess ruptures. [ 38 ]


Skin abscesses are common and have become more common in recent years. [ 1 ]  Risk factors include  intravenous drug use , with rates reported as high as 65% among users. [ 2 ]  In 2005, in the United States 3.2 million people went to the emergency department for an abscess. [ 5 ]  In Australia around 13,000 people were hospitalized in 2008 for the disease. [ 13 ]


The  Latin  medical  aphorism  " ubi pus, ibi evacua " expresses "where there is pus, there evacuate it" and is classical advice in the culture of Western medicine. [ 39 ]


Needle exchange programmes  often administer or provide referrals for abscess treatment to  injection drug users  as part of a  harm reduction  public health strategy. [ 40 ] [ 41 ]


An abscess is so called "abscess" because there is an  abscessus  (a going away or departure) of portions of the animal tissue from each other to make room for the suppurated matter lodged between them. [ 42 ]


The word carbuncle is believed to have originated from the Latin:  carbunculus , originally a small coal; diminutive of  carbon- ,  carbo : charcoal or ember, but also a  carbuncle stone , "precious stones of a red or fiery colour", usually  garnets . [ 43 ]


The following types of abscess are listed in the medical dictionary: [ 44 ]


An  accessory  bile duct  is a  conduit  that transports  bile  and is considered to be  supernumerary  or auxiliary to the  biliary tree . [ 1 ]


It may be described by its location relative to the  gallbladder  as supravesicular [ 2 ] [ 3 ]  (superior to the gallbladder body) or subvesicular [ 4 ] [ 5 ]  (inferior to the gallbladder body).


In the surgical literature, the term  duct of Luschka  is used to refer to an accessory bile duct.  They are small ducts that distinctly enter the gallbladder bed, or small tributaries of minor intrahepatic radicals of the right hepatic ductal system. [ 6 ]  Originating from the hepatic parenchyma the accessory bile duct may enter a large bile duct or the gallbladder at any location. [ 7 ]  Rarely it is found to be connected directly to the GIT. [ 8 ]  They may not always drain bile and sometimes can have blind distal ends. [ 2 ]  One study showed them originating from the liver parenchyma of the right anterior inferior dorsal subsegment or from the connective tissue of the gallbladder bed. The study showed the distal connections ending at the hepatic right anterior inferior dorsal branch, hepatic right anterior branch, right hepatic duct, or common hepatic duct. [ 4 ]


The term  duct of Luschka  is ambiguous, as it may refer to supravesicular [ 2 ] [ 3 ]  or subvesicular ducts. [ 4 ] [ 5 ]  Supravesicular ducts are typically in the gallbladder bed. A 2012 review suggested that the term  duct of Luschka  should be abandoned because of this ambiguity and replaced by the more specific term  subvesical bile duct . [ 9 ]  As well, the exact origin and drainage locations of the relevant duct(s) varied greatly between patients.


Of 116 articles, 54 provided detailed anatomic information identifying 238 subvesical ducts, most of which represented accessory ducts. The origin and drainage of these ducts were limited primarily to the right lobe of the liver, but great variation was seen.


Although they may not drain any liver  parenchyma , they can be a source of a bile leak or biliary  peritonitis  after  cholecystectomy  in both adults and children. If an accessory bile duct goes unrecognized at the time of the gallbladder removal, 5–7 days post-operative the patient will develop bile  peritonitis , [ 10 ]  an easily treatable complication with a morbidity rate of 44% if left untreated.


Often diagnosed by  HIDA scan , a bile leak from an accessory bile duct post-op can be treated with a temporary biliary stent [ citation needed ]  to redirect the bile from the liver into the intestine and allow the accessory duct to spontaneously seal itself or using a drainage guided by radiology. [ 11 ]


The term is named after German anatomist  Hubert von Luschka  (1820-1875) [ 12 ] [ 13 ]  who described the first case in 1863. [ 4 ]


An  acute abdomen  refers to a sudden, severe  abdominal pain . [ 1 ]  It is in many cases a medical emergency, requiring urgent and specific diagnosis. Several causes need immediate  surgical treatment .


Common causes of an acute abdomen include a  gastrointestinal perforation ,  peptic ulcer disease ,  mesenteric ischemia ,  acute cholecystitis ,  appendicitis ,  diverticulitis ,  pancreatitis , and an abdominal hemorrhage. However, this is a non-exhaustative list and other less common causes may also lead to an acute abdomen. [ 2 ]  In pregnant patient, a  tubo-ovarian abscess , ruptured ovarian cyst or a ruptured  ectopic pregnancy  are common causes of an acute abdomen. [ 2 ]


Vascular disorders are more likely to affect the small bowel than the large bowel. Arterial supply to the intestines is provided by the superior and inferior mesenteric arteries (SMA and IMA respectively), both of which are direct branches of the aorta. [ 3 ]


Clinically, patients present with diffuse abdominal pain, bowel distention, and bloody diarrhea. On physical exam, bowel sounds will be absent. Laboratory tests reveal a neutrophilic leukocytosis, sometimes with a left shift, and increased serum amylase. Abdominal radiography will show many air-fluid levels, as well as widespread edema. Acute ischemic abdomen is a surgical emergency. Typically, treatment involves removal of the region of the bowel that has undergone  infarction , and subsequent  anastomosis  of the remaining healthy tissue. [ 4 ]


Traditionally, the use of  opiates  or other pain medications in patients with an acute abdomen has been discouraged before the clinical examination because of the concern that pain medications may mask the signs and symptoms of the condition and therefore may lead to a delay in diagnosis. However, the scientific literature has shown that early administration of pain medications, including opiates, in those with acute abdomen does not lead to delayed diagnosis, delayed treatment or errors in management (the incorrect surgical treatment administered or performing un-necessary surgery). [ 5 ] [ 6 ] [ 2 ]  In a meta-analysis of those with acute appendicitis, early administration of opiates was found to alter treatment approach (with a slightly higher rate of appendectomy in those who received opiates) but diagnostic accuracy and surgical outcomes were unaffected by pain medication use. [ 7 ]  Clinical guidelines also recommend early analgesic use before a cause is established. [ 8 ]


Medical imaging  aids in the diagnosis of potential causes of an acute abdomen. A  CT scan  or  ultrasound  of the abdomen and pelvis are the preferred imaging modalities in the evaluate of an acute abdomen. [ 8 ]  The use of  radiocontrast agents  with CT scans improve diagnostic accuracy. [ 2 ]  Some authors advocate for the use of  CT angiography  with contrast of the abdomen and pelvis as the preferred imaging modality. [ 2 ]  An ultrasound is the preferred imaging modality in pregnant patients as CT scans expose the fetus to ionizing radiation which may lead to adverse pregnancy outcomes. [ 2 ]  An  abdominal x-ray  may show  free air  in the abdominal cavity due to a perforation in the gastrointestinal tract. However, abdominal x-ray is not recommended as part of the diagnostic evaluation in acute abdomen due to its low sensitivity and specificity. [ 8 ] [ 2 ]  Delays in medical imaging acquisition and interpretation greater than 2 hours are associated with an increased risk of complications and death. [ 2 ] [ 9 ]


In a population based study of  Medicare  patients in the United States, Black patients who were admitted to the hospital for an acute abdomen requiring general surgery consultation were 14% less likely to receive surgical consultation as compared to White patients. These racial disparities in care persisted (with an 11% difference) when socioeconomic factors were standardized. [ 10 ]  In another population based study in the United States, Black patients and patients from other racial minority groups were 22-30% less likely to receive pain medication for an acute abdomen as compared to White patients. [ 11 ]


The  Alvarado score  is a clinical scoring system used in the diagnosis of  appendicitis . [ 1 ]   Alvarado scoring has largely been superseded as a clinical prediction tool by the  Appendicitis Inflammatory Response score . [ 2 ] [ 3 ] [ 4 ]


Also known by the  mnemonic  MANTRELS, the scale has 6 clinical items (3  signs  and 3  symptoms ) and 2 laboratory measurements, each given an additive point score, with a maximum of 10 points possible. [ 5 ]   It was introduced in 1986 by Dr. Alfredo Alvarado and although meant for pregnant females, it has been extensively validated in the non-pregnant population.  A known limitation of the score is that only 20% of elderly patients present with classic findings on which the score focuses. [ 5 ]  A modified Alvarado score is at present in use. [ 6 ]


Elements from the person's  history , the  physical examination  and from laboratory tests: [ 7 ]


The two most important factors, tenderness in the right lower quadrant and leukocytosis, are assigned two points, and the six other factors are assigned one point each, for a possible total score of ten points. [ 7 ]


A score of 5 or 6 is compatible with the diagnosis of acute appendicitis. A score of 7 or 8 indicates probable appendicitis, and a score of 9 or 10 indicates very probable acute appendicitis. [ 8 ]


The original Alvarado score describes a possible total of 10 points, but those medical facilities that are unable to perform a differential white blood cell count, are using a Modified Alvarado Score with a total of 9 points which could be not as accurate as the original score. The high diagnostic value of the score has been confirmed in a number of studies across the world. The consensus is that the Alvarado score is a noninvasive, safe, diagnostic method, which is simple, reliable, repeatable, and able to guide the clinician in the management of the case. However, a recent study demonstrated a sensitivity of only 72% of the Modified Alvarado Score for detection of appendicitis which has led to criticism of the usefulness of the score. Scores of less than five in children were useful for eliminating appendicitis from the differential diagnosis. [ 9 ]


It carries high significance in the diagnosis of acute appendicitis. [ 10 ]


Online calculator of the Alvarado Score


An  appendectomy  ( American English ) or  appendicectomy  ( British English ) is a  surgical operation  in which the  vermiform appendix  (a portion of the intestine) is removed. Appendectomy is normally performed as an urgent or emergency procedure to treat complicated acute  appendicitis . [ 1 ]


Appendectomy may be performed  laparoscopically  (as  minimally invasive surgery ) or as an open operation. [ 2 ]  Over the 2010s, surgical practice has increasingly moved towards routinely offering laparoscopic appendicectomy; for example in the  United Kingdom  over 95% of adult appendicectomies are planned as laparoscopic procedures. [ 3 ]  Laparoscopy is often used if the diagnosis is in doubt, or in order to leave a less visible surgical scar. Recovery may be slightly faster after laparoscopic surgery, although the laparoscopic procedure itself is more expensive and resource-intensive than open surgery and generally takes longer. Advanced pelvic sepsis occasionally requires a lower midline  laparotomy .


Complicated (perforated) appendicitis should undergo prompt surgical intervention. [ 1 ]   There has been significant recent trial evidence that uncomplicated appendicitis can be treated with either antibiotics or appendicectomy, [ 4 ] [ 5 ]  with 51% of those treated with antibiotics avoiding an appendectomy after 3 years. [ 6 ]  After appendicectomy the main difference in treatment is the length of time the antibiotics are administered. For uncomplicated appendicitis, antibiotics should be continued up to 24 hours post-operatively. For complicated appendicitis, antibiotics should be continued for anywhere between 3 and 7 days. [ 1 ]  An interval appendectomy is generally performed 6–8 weeks after conservative management with antibiotics for special cases, such as perforated appendicitis. [ 7 ]  Delay of appendectomy 24 hours after admission for symptoms of appendicitis has not shown to increase risk of perforation or other complications. [ 8 ]


In general terms, the procedure for an open appendectomy is:


The standardization of an incision is not best practice when performing an appendectomy given that the appendix is a mobile organ. [ 9 ]  A physical exam should be performed prior to the operation and the incision should be chosen based on the point of maximal tenderness to palpation. [ 9 ]


These incisions are placed for appendectomy:


Over the past decade, the outcomes of laparoscopic appendectomies have compared favorably to those for open appendectomies because of decreased pain, fewer postoperative complications, shorter hospitalization, earlier mobilization, earlier return to work, and better  cosmesis ; however, despite these advantages, efforts are still being made to decrease abdominal incision and visible scars after laparoscopy. [ 10 ]  Recent research has led to the development of  natural orifice transluminal endoscopic surgery  (NOTES); however, numerous difficulties need to be overcome before a wider clinical application of NOTES is adopted, including complications such as the opening of hollow viscera, failed sutures, a lack of fully developed instrumentation, and the necessity of reliable cost-benefit analyses. [ 11 ]


Many surgeons have attempted to reduce incisional morbidity and improve cosmetic outcomes in laparoscopic appendectomy by using fewer and smaller ports. Kollmar  et al.  described moving laparoscopic incisions to hide them in the natural camouflages like the suprapubic hairline to improve cosmesis. Additionally, reports in the literature indicate that minilaparoscopic appendectomy using 2– or 3-mm or even smaller instruments along with one 12-mm port minimizes pain and improves cosmesis. More recently, studies by Ates  et al.  and Roberts  et al.  have described variants of an  intracorporeal  sling-based single-port laparoscopic appendectomy with good clinical results. [ 11 ]


Also, a trend is increasing towards single-incision laparoscopic surgery (SILS), using a special multiport umbilical trocar. [ 12 ]  With SILS, a more conventional view of the field of surgery is seen compared to NOTES. The equipment used for SILS is familiar to surgeons already doing laparoscopic surgery. Most importantly, it is easy to convert SILS to conventional laparoscopy by adding a few trocars; this conversion to conventional laparoscopy is called 'port rescue'. SILS has been shown to be feasible, reasonably safe, and cosmetically advantageous, compared to standard laparoscopy; however, this newer technique involves specialized instruments and is more difficult to learn because of a loss of triangulation, clashing of instruments, crossing of instruments (cross triangulation), and a lack of maneuverability. [ 11 ]   The additional problem of decreased exposure and the added financial burden of procuring special articulating or curved coaxial instruments exist. SILS is still evolving, being used successfully in many centres, but with some way to go before it becomes mainstream. This limits its widespread use, especially in rural or peripheral centres with limited resources. [ 11 ]


Pediatric patients have a mobile cecum, which allows externalization of the cecal appendix through the umbilicus in most cases. This has led to the development of surgical techniques such as laparoscopic-assisted transumbilical appendectomy, which allows the entire surgery to be performed with a single umbilical incision and has significant advantages in terms of both recovery and aesthetic outcome. [ 13 ]


Appendicitis is the most common emergent general surgery related problem to arise during pregnancy. There is a natural elevation in white blood cell count in addition to anatomical changes of the appendix that occur during pregnancy. [ 14 ]  These findings, in addition to non-specific abdominal symptoms make appendicitis difficult to diagnose. Appendicitis develops most commonly in the second trimester. [ 2 ]  If appendicitis develops in a  pregnant  woman, an appendectomy is usually performed and should not harm the  fetus . [ 15 ]  The risk of premature delivery is about 10%. [ 16 ]  The risk of fetal death in the perioperative period after an appendectomy for early acute appendicitis is 3 to 5%. The risk of fetal death is 20% in perforated appendicitis. [ 17 ]


There has been debate regarding which surgical approach is preferred during pregnancy. Overall, there is no increased risk of fetal loss or preterm delivery with the laparoscopic approach (LA) as compared to the open approach (OA). However, the LA was associated with shorter length of stay in the hospital as well as reduced risk of wound infection. [ 2 ]


Patient positioning is of utmost importance to ensure safety of the fetus during the procedure. This is especially important during the third trimester due to the potential of compression of the inferior vena cava leading by the enlarged uterus. Placing the patient in a 30-degree left lateral decubitus position alleviates this pressure and prevents fetal distress. [ 14 ]


One area of concern related to the LA during pregnancy is  pneumoperitoneum . This causes an increase in the intra-abdominal pressure, leading to decreased venous return and therefore, decreased cardiac output. The decreased cardiac output may lead to fetal acidosis and cause distress. However, an animal pregnancy model demonstrated that a 10-12mmHg insufflation pressure demonstrated no adverse effects on the fetus. SAGES (Society of American Gastrointestinal and Endoscopic Surgeons) currently recommends an insufflation pressure of 10-15mmHg during pregnancy. [ 2 ]


A study from 2010 found that the average hospital stay for people with appendicitis in the United States was 1.8 days. For people with a perforated (ruptured) appendix, the average length of stay was 5.2 days. [ 18 ]


Recovery time from the operation varies from person to person. Some take up to three weeks before being completely active; for others, it can be a matter of days. In the case of a laparoscopic operation, the patient has three stapled scars of about an inch (2.5 cm) in length, between the navel and pubic hair line. When an open appendectomy has been performed, the patient has a 2– to 3-inch (5–7.5 cm) scar, which will initially be heavily bruised. [ 19 ]


One of the most common post-operative complications associated with an appendectomy is the development of a surgical site infection (SSI). [ 20 ]  Signs and symptoms indicative of a superficial SSI are redness, swelling, and tenderness surrounding the incision and are most likely to arise on post-operative day 4 or 5. These symptoms oftentimes precede fluid drainage from the incision. Tenderness extending beyond the redness that surrounds the incision, in addition to the development of cutaneous  vesicles  or bullae may be indicative of a deep SSI. [ 20 ]


Patients with complicated appendicitis (perforated appendicitis) are more likely to develop a SSI, abdominal abscess, or pelvic abscess during the post-operative period. Placement of an abdominal drain was originally thought to reduce the risk of these post-operative complications. However, abdominal drains have not been found to play a significant role in reducing SSIs and have led to increased length of stay in the hospital in addition to increased cost of the operation. [ 21 ]


About 327,000 appendectomies were performed during U.S. hospital stays in 2011, a rate of 10.5 procedures per 10,000 population. Appendectomies accounted for 2.1% of all operating-room procedures in 2011. [ 22 ]


The first recorded successful appendectomy was performed in September 1731 by English surgeon William Cookesley on Abraham Pike, a chimney sweep. [ 23 ] [ 24 ]  The second was on December 6, 1735, at  St. George's Hospital  in London, when French surgeon  Claudius Amyand  described the presence of a perforated appendix within the  inguinal hernial  sac of an 11-year-old boy. [ 8 ]  The organ had apparently been perforated by a pin the boy had swallowed. The patient, Hanvil Andersen, made a recovery and was discharged a month later. [ 25 ]


Harry Hancock performed the first  abdominal surgery  for appendicitis in 1848, but he did not remove the appendix. [ 26 ]  In 1889 in New York City,  Charles McBurney  described the presentation and pathogenesis of appendicitis accurately and developed the teaching that an early appendectomy was the best treatment to avoid perforation and  peritonitis .


Some cases of autoappendectomies have occurred. One was attempted by  Evan O'Neill Kane  in 1921, but the operation was completed by his assistants. Another was  Leonid Rogozov , who in 1961 had to perform the operation on himself as he was the only doctor on a remote Antarctic base. [ 27 ] [ 28 ]


On September 13, 1980,  Kurt Semm  performed the first  laparoscopic  appendectomy, opening up the path for a much wider application of minimally invasive surgery. [ 29 ] [ 30 ]


While appendectomy is a standard surgical procedure, its cost has been found to vary considerably in the United States. A 2012 study  analyzed 2009 data from nearly 20,000 adult patients treated for appendicitis in California hospitals. Researchers examined "only uncomplicated episodes of acute appendicitis" that involved "visits for patients 18 to 59 years old with hospitalization that lasted fewer than four days with routine discharges to home." The lowest charge for removal of an appendix was $1,529 and the highest $182,955, almost 120 times greater. The median charge was $33,611. [ 31 ] [ 32 ]  While the study was limited to California, the researchers indicated that the results were applicable anywhere in the United States. Many, but not all, patients are covered by some sort of  medical insurance . [ 33 ]


A study by the  Agency for Healthcare Research and Quality  found that in 2010, the average cost for a stay in the United States involving appendicitis was $7,800. For stays where the appendix had ruptured, the average cost was $12,800. The majority of patients seen in the hospital were covered by private insurance. [ 18 ]


Appendicitis  is  inflammation  of the  appendix . [ 2 ]  Symptoms commonly include right lower  abdominal pain ,  nausea ,  vomiting , and  decreased appetite . [ 2 ]  However, approximately 40% of people do not have these typical symptoms. [ 2 ]  Severe complications of a ruptured appendix include widespread, painful  inflammation of the inner lining of the abdominal wall  and  sepsis . [ 3 ]


Appendicitis is primarily caused by a blockage of the  hollow portion  in the appendix. [ 10 ]  This blockage typically results from a  faecolith , a calcified "stone" made of feces. [ 6 ]  Some studies show a correlation between appendicoliths and disease severity. [ 11 ]  Other factors such as inflamed  lymphoid tissue  from a viral infection,  intestinal parasites ,  gallstone , or  tumors  may also lead to this blockage. [ 6 ]  When the appendix becomes blocked, it experiences increased pressure, reduced blood flow, and bacterial growth, resulting in inflammation. [ 6 ] [ 12 ]  This combination of factors causes tissue injury and, ultimately, tissue death. [ 13 ]  If this process is left untreated, it can lead to the appendix rupturing, which releases bacteria into the  abdominal cavity , potentially leading to severe complications. [ 13 ] [ 14 ]


The diagnosis of appendicitis is largely based on the person's signs and symptoms. [ 12 ]  In cases where the diagnosis is unclear, close observation,  medical imaging , and laboratory tests can be helpful. [ 4 ]  The two most commonly used imaging tests for diagnosing appendicitis are ultrasound and computed tomography (CT scan). [ 4 ]  CT scan is more accurate than ultrasound in detecting acute appendicitis. [ 15 ]  However, ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from CT scans. [ 4 ]  Although ultrasound may aid in diagnosis, its main role is in identifying important differentials, such as ovarian pathology in females or mesenteric adenitis in children.


The standard treatment for acute appendicitis involves the  surgical removal of the inflamed appendix . [ 6 ] [ 12 ]  This procedure can be performed either through an open incision in the abdomen ( laparotomy ) or using minimally invasive techniques with small incisions and cameras ( laparoscopy ). Surgery is essential to reduce the risk of complications or potential death associated with the rupture of the appendix. [ 3 ]   Antibiotics  may be equally effective in certain cases of non-ruptured appendicitis, [ 16 ] [ 7 ] [ 17 ]  but 31% will undergo appendectomy within one year. [ 18 ]  It is one of the most common and significant causes of sudden abdominal  pain . In 2015, approximately 11.6 million cases of appendicitis were reported, resulting in around 50,100 deaths worldwide. [ 8 ] [ 9 ]  In the United States, appendicitis is one of the most common causes of sudden abdominal pain requiring surgery. [ 2 ]  Annually, more than 300,000 individuals in the United States undergo surgical removal of their appendix. [ 19 ]


The presentation of acute appendicitis includes acute abdominal pain, nausea, vomiting, and fever. As the appendix becomes more swollen and inflamed, it begins to irritate the adjoining abdominal wall. This leads the pain to localize at  the right lower quadrant . This classic migration of pain may not appear in children under three years. This pain can be triggered by a sharp pain feeling. Pain from appendicitis may begin as dull pain around the navel. After several hours, the pain usually migrates towards the right lower quadrant, where it becomes localized. Symptoms include localized findings in the right  iliac fossa . The abdominal wall becomes very sensitive to gentle pressure ( palpation ). There is pain in the sudden release of deep tension in the lower abdomen ( Blumberg's sign ). If the appendix is retrocecal (localized behind the  cecum ), even deep pressure in the right lower quadrant may fail to elicit tenderness (silent appendix). This is because the  cecum , distended with gas, protects the inflamed appendix from pressure. Similarly, if the appendix lies entirely within the pelvis, there is typically a complete absence of abdominal rigidity. In such cases, a digital  rectal examination  elicits tenderness in the rectovesical pouch. Coughing causes point tenderness in this area ( McBurney's point ), called  Dunphy's sign . [ medical citation needed ]


Acute appendicitis seems to be the result of a primary obstruction of the  appendix . [ 20 ] [ 10 ]  Once this obstruction occurs, the appendix becomes filled with  mucus  and swells. This continued production of mucus leads to increased pressures within the lumen and the walls of the appendix. The increased pressure results in  thrombosis  and  occlusion  of the small vessels, and stasis of  lymphatic flow . At this point, spontaneous recovery rarely occurs. As the occlusion of blood vessels progresses, the appendix becomes  ischemic  and then  necrotic . As  bacteria  begin to leak out through the dying walls,  pus  forms within and around the appendix (suppuration). The result is appendiceal rupture (a 'burst appendix') causing  peritonitis , which may lead to  sepsis  and in rare cases,  death . These events are responsible for the slowly evolving abdominal pain and other commonly associated symptoms. [ 13 ]


The causative agents include  bezoars , foreign bodies,  trauma , [ 21 ] [ 22 ]   lymphadenitis  and, most commonly, calcified fecal deposits that are known as  appendicoliths  or  fecaliths . [ 23 ] [ 24 ]  The occurrence of  obstructing fecaliths  has attracted attention since their presence in people with appendicitis is higher in developed than in developing countries. [ 25 ]  In addition, an appendiceal fecalith is commonly associated with complicated appendicitis. [ 26 ]  Fecal stasis and arrest may play a role, as demonstrated by people with acute appendicitis having fewer bowel movements per week compared with healthy controls. [ 24 ] [ 27 ]


The occurrence of a fecalith in the appendix was thought to be attributed to a right-sided fecal retention reservoir in the colon and a prolonged transit time. However, a prolonged transit time was not observed in subsequent studies. [ 28 ]   Diverticular disease  and  adenomatous polyps  was historically unknown and  colon cancer  was exceedingly rare in communities where appendicitis itself was rare or absent, such as various African communities. Studies have implicated a transition to a  Western diet  lower in  fiber  in rising frequencies of appendicitis as well as the other aforementioned colonic diseases in these communities. [ 29 ] [ 30 ]  And acute appendicitis has been shown to occur antecedent to cancer in the colon and rectum. [ 31 ]  Several studies offer evidence that a low fiber intake is involved in the pathogenesis of appendicitis. [ 32 ] [ 33 ] [ 34 ]  This low intake of dietary fiber is in accordance with the occurrence of a right-sided fecal reservoir and the fact that dietary fiber reduces transit time. [ 35 ]


The physician will ask questions to get the  health history , assess the patient's  symptoms , do a complete  physical exam , and order both laboratory and imaging tests. [ 36 ]  Appendicitis symptoms fall into two categories, typical and atypical. [ 37 ]


Typical appendicitis is characterized by a migratory  right iliac fossa  pain associated with nausea, and anorexia, which can occur with or without vomiting and localized muscle stiffness/ generalized  guarding . [ 37 ]  It is possible the pain could localize to  the left lower quadrant  in people with  situs inversus totalis . [ 38 ]  The combination of migrated  umbilical  pain to the right  lower quadrant , loss of appetite for food, nausea, unsustained  vomiting , and mild  fever  is classic. [ 37 ]


Atypical histories lack this typical progression and may include pain in the right lower quadrant as an initial symptom. Irritation of the peritoneum (inside lining of the abdominal wall) can lead to increased pain on movement, or jolting, for example going over  speed bumps . [ 39 ]  Atypical histories often require imaging with ultrasound or CT scanning. [ 3 ]


During the early stages of appendicitis diagnosis, it is common for  physical exams  to present inconspicuous findings. Signs of inflammation become noticeable as the disease progresses. These signs may include [ 40 ]


While there is no laboratory test specific for appendicitis, a  complete blood count  (CBC) is done to check for signs of infection or inflammation. Although 70–90 percent of people with appendicitis may have an elevated  white blood cell (WBC) count , many other abdominal and pelvic conditions can cause the WBC count to be elevated. [ 48 ]  However, a high  WBC count  may not alone represent a solid indicator of appendicitis but rather an inflammation  [ 15 ]  but the neutrophil ratio was more sensitive and specific for acute appendicitis. [ 49 ]


In children,  neutrophil-lymphocyte ratio (NLR)
demonstrates a high degree of accuracy in the diagnosis of acute appendicitis and distinguishes complicated appendicitis from the simple one. [ 50 ]
75–78 percent of the patients have  neutrophilia . [ 42 ]  Delta-neutrophil index (DNI) is a valuable parameter that helps in the diagnosis of histologically normal appendicitis and distinguishing between simple and complicated appendicitis. [ 51 ]


A  C-reactive protein (CRP) blood test  will be ordered by the doctor to find out if there are any further causes of inflammation. [ 36 ]  The C-reactive protein/albumin (CRP/ALB) ratio can be a reliable predictor of complicated appendicitis. [ 52 ]


The  urinalysis  is important for ruling out a urinary tract infection as the cause of abdominal pain. The presence of more than 20 WBC per high-power field in the urine is more suggestive of a urinary tract disorder. [ 48 ]


If the patient is a female, a  pregnancy test  will be ordered. [ 36 ]


In children, the clinical examination is important to determine which children with abdominal pain should receive immediate surgical consultation and which should receive diagnostic imaging. [ 53 ]  Because of the health risks of exposing children to radiation, ultrasound is the preferred first choice with CT scan being a legitimate follow-up if the ultrasound is inconclusive. [ 54 ] [ 55 ] [ 56 ]  CT scan is more accurate than ultrasound for the diagnosis of appendicitis in adults and adolescents. CT scan has a  sensitivity  of 94%,  specificity  of 95%. Ultrasonography had an overall  sensitivity  of 86%, a  specificity  of 81%. [ 57 ]


Abdominal ultrasonography , preferably with  doppler sonography , is useful to detect appendicitis, especially in children. Ultrasound can show the free fluid collection in the right iliac fossa, along with a visible appendix with increased blood flow when using color Doppler, and noncompressibility of the appendix, as it is essentially a walled-off abscess. Other secondary sonographic signs of acute appendicitis include the presence of echogenic mesenteric fat surrounding the appendix and the acoustic shadowing of an appendicolith. [ 58 ]  In some cases (approximately 5%), [ 59 ]  ultrasonography of the  iliac fossa  does not reveal any abnormalities despite the presence of appendicitis. This false-negative finding is especially true of early appendicitis before the appendix has become significantly distended. Also, false-negative findings are more common in adults where larger amounts of fat and bowel gas make visualizing the appendix technically difficult. Despite these limitations, sonographic imaging with experienced hands can often distinguish between appendicitis and other diseases with similar symptoms. Some of these conditions include  inflammation  of  lymph nodes  near the appendix or pain originating from other pelvic organs such as the ovaries or Fallopian tubes. Ultrasounds may be either done by the radiology department or by the emergency physician. [ 60 ]


Where it is readily available,  computed tomography  (CT) has become frequently used, especially in people whose diagnosis is not obvious on history and physical examination. Although some concerns about interpretation are identified, a 2019 Cochrane review found that the sensitivity and specificity of CT for the diagnosis of acute appendicitis in adults was high. [ 62 ]   Concerns about radiation tend to limit use of CT in pregnant women and in children, especially with the increasingly widespread usage of MRI. [ 63 ] [ 64 ]


The accurate diagnosis of appendicitis is multi-tiered, with the size of the appendix having the strongest  positive predictive value , while indirect features can either increase or decrease sensitivity and specificity. A size of over 6 mm is both 95% sensitive and specific for appendicitis. [ 65 ]


However, because the appendix can be filled with fecal material, causing intraluminal distention, this criterion has shown limited utility in more recent meta-analyses. [ 66 ]  This is as opposed to ultrasound, in which the wall of the appendix can be more easily distinguished from intraluminal feces. In such scenarios, ancillary features such as increased wall enhancement as compared to adjacent bowel and inflammation of the surrounding fat, or fat stranding, can be supportive of the diagnosis. However, their absence does not preclude it. In severe cases with perforation, an adjacent  phlegmon  or  abscess  can be seen. Dense fluid layering in the pelvis can also result, related to either  pus  or  enteric spillage . When patients are thin or younger, the relative absence of fat can make the appendix and surrounding fat stranding difficult to see. [ 66 ]


Magnetic resonance imaging  (MRI) use has become increasingly common for diagnosis of appendicitis in children and pregnant patients due to the radiation dosage that, while of nearly negligible risk in healthy adults, can be harmful to children or the developing baby. [ 67 ]  In pregnancy, it is more useful during the second and third trimester, particularly as the enlargening uterus displaces the appendix, making it difficult to find by ultrasound. The periappendiceal stranding that is reflected on CT by fat stranding on MRI appears as an increased fluid signal on T2 weighted sequences. First-trimester pregnancies are usually not candidates for MRI, as the fetus is still undergoing  organogenesis , and there are no long-term studies to date regarding its potential risks or side effects. [ 68 ]


In general, plain abdominal radiography (PAR) is not useful in making the diagnosis of appendicitis and should not be routinely obtained from a person being evaluated for appendicitis. [ 69 ] [ 70 ]  Plain abdominal films may be useful for the detection of  ureteral   calculi ,  small bowel obstruction , or  perforated ulcer , but these conditions are rarely confused with appendicitis. [ 71 ]  An opaque  fecalith  can be identified in the right lower quadrant in fewer than 5% of people being evaluated for appendicitis. [ 48 ]  A  barium enema  has proven to be a poor diagnostic tool for appendicitis. While failure of the appendix to fill during a barium enema has been associated with appendicitis, up to 20% of normal appendices do not fill. [ 71 ]


Several scoring systems have been developed to try to identify people who are likely to have appendicitis. [ 72 ]  The performance of scores such as the  Alvarado score  and the Pediatric Appendicitis Score, however, are variable. [ 73 ]


The Alvarado score is the most known scoring system. A score below 5 suggests against a diagnosis of appendicitis, whereas a score of 7 or more is predictive of acute appendicitis. In a person with an equivocal score of 5 or 6, a CT scan or ultrasound exam may be used to reduce the rate of negative appendectomy.


Even for clinically certain appendicitis, routine  histopathology  examination of appendectomy specimens is of value for identifying unsuspected pathologies requiring further postoperative management. [ 74 ]  Notably,  appendix cancer  is found incidentally in about 1% of appendectomy specimens. [ 75 ]


Pathology diagnosis of appendicitis can be made by detecting a  neutrophilic  infiltrate of the  muscularis propria .


Periappendicitis (inflammation of tissues around the appendix) is often found in conjunction with other abdominal pathology. [ 76 ]


Children:  Gastroenteritis ,  mesenteric adenitis ,  Meckel's diverticulitis ,  intussusception ,  Henoch–Schönlein purpura , lobar  pneumonia ,  urinary tract infection  (abdominal pain in the absence of other symptoms can occur in children with UTI), new-onset  Crohn's disease  or  ulcerative colitis ,  pancreatitis , and abdominal trauma from  child abuse ;  distal intestinal obstruction syndrome  in children with cystic fibrosis;  typhlitis  in children with leukemia.


Women: A pregnancy test is important for all women of childbearing age since an  ectopic pregnancy  can have signs and symptoms similar to those of appendicitis. Other obstetrical/ gynecological causes of similar abdominal pain in women include  pelvic inflammatory disease ,  ovarian torsion ,  menarche , dysmenorrhea,  endometriosis , and  Mittelschmerz  (the passing of an egg in the ovaries approximately two weeks before menstruation). [ 78 ]


Men:  testicular torsion


Adults: new-onset  Crohn disease ,  ulcerative colitis , regional enteritis,  cholecystitis ,  renal colic , perforated  peptic ulcer ,  pancreatitis ,  rectus sheath hematoma  and  epiploic appendagitis .


Elderly:  diverticulitis , intestinal obstruction,  colonic carcinoma ,  mesenteric ischemia , leaking  aortic aneurysm .


The term " pseudoappendicitis " is used to describe a condition mimicking appendicitis. [ 79 ]  It can be associated with  Yersinia enterocolitica . [ 80 ]


Acute appendicitis [ 81 ]  is typically managed by  surgery . While antibiotics are safe and effective for treating uncomplicated appendicitis, [ 16 ] [ 7 ] [ 82 ]  31% of people had a recurrence within a year and required an eventual appendectomy. [ 83 ]  Antibiotics are less effective if an  appendicolith  is present. [ 84 ]  While 51% of patients who were treated with antibiotics did not need an appendectomy three years after treatment, [ 85 ]  the cost effectiveness of surgery versus antibiotics is unclear [ 86 ]


Using antibiotics to prevent potential postoperative complications in emergency appendectomy procedures is recommended, and the antibiotics are effective when given to a person before, during, or after surgery. [ 87 ]


Pain medications (such as  morphine ) do not appear to affect the accuracy of the clinical diagnosis of appendicitis and therefore should be given early in the patient's care. [ 88 ]  Historically there were concerns among some general surgeons that analgesics would affect the clinical exam in children, and some recommended that they not be given until the surgeon was able to examine the person. [ 88 ]


The  surgical  procedure for the removal of the appendix is called an  appendectomy . Appendectomy can be performed through open or laparoscopic surgery. Laparoscopic appendectomy has several advantages over open appendectomy as an intervention for acute appendicitis. [ 89 ]


For over a century, laparotomy (open appendectomy) was the standard treatment for acute appendicitis. [ 90 ]  This procedure consists of the removal of the infected appendix through a single large incision in the lower right area of the abdomen. [ 91 ]  The incision in a laparotomy is usually 2 to 3 inches (51 to 76 mm) long.


During an open appendectomy, the person with suspected appendicitis is placed under general  anesthesia  to keep the muscles completely relaxed and to keep the person unconscious. The incision is two to three inches (76 mm) long, and it is made in the right lower abdomen, several inches above the  hip bone . Once the incision opens the abdomen cavity, and the appendix is identified, the  surgeon  removes the infected tissue and cuts the appendix from the surrounding tissue. After careful and close inspection of the infected area, and ensuring there are no signs that surrounding tissues are damaged or infected.  In case of complicated appendicitis managed by an emergency open appendectomy, abdominal drainage (a temporary tube from the abdomen to the outside to avoid abscess formation) may be inserted, but this may increase the hospital stay. [ 92 ] [ needs update ]  The surgeon will start closing the incision. This means sewing the muscles and using  surgical staples  or  stitches  to close the skin up. To prevent infections, the incision is covered with a  sterile bandage  or surgical adhesive.


Laparoscopic appendectomy was introduced in 1983 and has become an increasingly prevalent intervention for acute appendicitis. [ 93 ]  This surgical procedure consists of making three to four incisions in the abdomen, each 0.25 to 0.5 inches (6.4 to 12.7 mm) long. This type of appendectomy is made by inserting a special surgical tool called a laparoscope into one of the incisions. The laparoscope is connected to a monitor outside the person's body, and it is designed to help the surgeon inspect the infected area in the abdomen. The other two incisions are made for the specific removal of the appendix by using  surgical instruments . Laparoscopic surgery requires  general anesthesia , and it can last up to two hours. Laparoscopic appendectomy has several advantages over open appendectomy, including a shorter post-operative recovery, less post-operative pain, and a lower superficial surgical site infection rate. However, the occurrence of an intra-abdominal abscess is almost three times more prevalent in laparoscopic appendectomy than open appendectomy. [ 94 ]


In pediatric patients, the high mobility of the cecum allows externalization of the appendix through the umbilicus, and the entire procedure can be performed with a single incision. Laparoscopic-assisted transumbilical appendectomy is a relatively recent technique but with a long published series and very good surgical and aesthetic results. [ 95 ]


The treatment begins by  keeping the person who will be having surgery from eating or drinking  for a given period, usually overnight. An  intravenous drip  is used to hydrate the person who will be having surgery.  Antibiotics  given intravenously such as  cefuroxime  and  metronidazole  may be administered early to help kill bacteria and thus reduce the spread of infection in the abdomen and postoperative complications in the abdomen or wound. Equivocal cases may become more difficult to assess with antibiotic treatment and benefit from serial examinations. If the stomach is empty (no food in the past six hours), general anaesthesia is usually used. Otherwise,  spinal anaesthesia  may be used.


Once the decision to perform an  appendectomy  has been made, the preparation procedure takes approximately one to two hours. Meanwhile, the surgeon will explain the surgery procedure and will present the risks that must be considered when performing an appendectomy. (With all surgeries there are risks that must be evaluated before performing the procedures.) The risks are different depending on the state of the appendix. If the appendix has not ruptured, the complication rate is only about 3% but if the appendix has ruptured, the complication rate rises to almost 59%. [ 96 ]  The most usual complications that can occur are pneumonia,  hernia  of the incision,  thrombophlebitis , bleeding and  adhesions . Evidence indicates that a delay in obtaining surgery after admission results in no measurable difference in outcomes to the person with appendicitis. [ 97 ] [ 98 ]


The surgeon will explain how long the recovery process should take. Abdomen hair is usually removed to avoid complications that may appear regarding the incision.


In most cases, patients going in for surgery experience nausea or vomiting that require medication before surgery. Antibiotics, along with pain medication, may be administered before appendectomies.


Hospital lengths of stay typically range from a few hours to a few days but can be a few weeks if complications occur. The recovery process may vary depending on the severity of the condition: if the appendix had ruptured or not before surgery. Appendix surgery recovery is generally much faster if the appendix does not rupture. [ 99 ]  It is important that people undergoing surgery respect their doctor's advice and limit their physical activity so the tissues can heal. Recovery after an appendectomy may not require diet changes or a lifestyle change.


The length of hospital stays for appendicitis varies on the severity of the condition. A study from the United States found that in 2010, the average appendicitis hospital stay was 1.8 days. For stays where the person's appendix had ruptured, the average length of stay was 5.2 days. [ 14 ]


After surgery, the patient will be transferred to a  postanesthesia care unit , so their vital signs can be closely monitored to detect anesthesia- or surgery-related complications. Pain medication may be administered if necessary. After patients are completely awake, they are moved to a hospital room to recover. Most individuals will be offered clear liquids the day after the surgery, then progress to a regular diet when the intestines start to function correctly. Patients are recommended to sit on the edge of the bed and walk short distances several times a day. Moving is mandatory, and pain medication may be given if necessary. Full recovery from appendectomies takes about four to six weeks but can be prolonged to up to eight weeks if the appendix has ruptured.


Most people with appendicitis recover quickly after surgical treatment, but complications can occur if treatment is delayed or if  peritonitis  occurs. Recovery time depends on age, condition, complications, and other circumstances, including the amount of alcohol consumption, but usually is between 10 and 28 days. For young children (around ten years old), the recovery takes three weeks.


The possibility of peritonitis is the reason why acute appendicitis warrants rapid evaluation and treatment. People with suspected appendicitis may have to undergo a  medical evacuation . Appendectomies have occasionally been performed in emergency conditions (i.e., not in a proper hospital) when a timely medical evacuation was impossible.


Typical acute appendicitis responds quickly to appendectomy and occasionally will resolve spontaneously. If appendicitis resolves spontaneously, it remains controversial whether an elective interval appendectomy should be performed to prevent a recurrent episode of appendicitis. Atypical appendicitis (associated with suppurative appendicitis) is more challenging to diagnose and is more apt to be complicated even when operated early. In either condition, prompt diagnosis and appendectomy yield the best results with full recovery in two to four weeks usually. Mortality and severe complications are unusual but do occur, especially if peritonitis persists and is untreated.


Another entity known as the appendicular lump is talked about. It happens when the appendix is not removed early during infection, and the omentum and intestine adhere to it, forming a palpable lump. During this period, surgery is risky unless there is pus formation evident by fever and toxicity or by ultrasound. Medical management treats the condition.


An unusual complication of an appendectomy is "stump appendicitis": inflammation occurs in the remnant appendiceal stump left after a prior incomplete appendectomy. [ 100 ]  Stump appendicitis can occur months to years after initial appendectomy and can be identified with imaging modalities such as ultrasound. [ 101 ]


The history of appendicitis traces back to ancient medical texts, though its clear clinical understanding emerged in the 19th century. Berengario da Carpi provided the first recorded description of the appendix in the 16th century, followed by  Andreas Vesalius  and  Gabriele Falloppio . Clinical understanding progressed in the 18th and 19th centuries, marked by Lorenz Heister's autopsy findings, Claudius Aymand's surgical intervention, and J. Mestivier's operation for appendicitis. Prior to the use of the term  appendicitis , it was described with terms including  perityphlitis ,  typhlitis ,  paratyphlitis , and  extra-peritoneal abscess of the right iliac fossa . [ 102 ]  The term "appendicitis" was coined by the American physician  Reginald Heber Fitz  in 1886, leading to standardized diagnosis and treatment, including Charles McBurney's identification of McBurney's point. Modern appendectomy techniques evolved in the early 20th century, coinciding with advancements in pathology, notably demonstrated by Ludwig Aschoff in 1908. [ 103 ] [ 104 ]


Appendicitis is most common between the ages of 5 and 40. [ 106 ]  In 2013, it resulted in 72,000 deaths globally, down from 88,000 in 1990. [ 107 ]


In the United States, there were nearly 293,000 hospitalizations involving appendicitis in 2010. [ 14 ]  Appendicitis is one of the most frequent diagnoses for emergency department visits resulting in hospitalization among children ages 5–17 years in the United States. [ 108 ]


Adults presenting to the emergency department with a known family history of appendicitis are more likely to have this disease than those without. [ 109 ]


Billroth I , more formally  Billroth's operation I , is an  operation  in which the  pylorus  is removed and the distal  stomach  is  anastomosed  directly to the  duodenum . [ 1 ] [ 2 ]


The operation is most closely associated with  Theodor Billroth , but was first described by  Polish   surgeon   Ludwik Rydygier . [ 2 ]


The surgical procedure is called a  gastroduodenostomy . [ 1 ]


Bowel obstruction , also known as  intestinal obstruction , is a mechanical or  functional obstruction  of the  intestines  which prevents the normal movement of the products of  digestion . [ 2 ] [ 5 ]  Either the  small bowel  or  large bowel  may be affected. [ 1 ]  Signs and symptoms include  abdominal pain ,  vomiting ,  bloating  and not passing  gas . [ 1 ]  Mechanical obstruction is the cause of about 5 to 15% of cases of  severe abdominal pain of sudden onset  requiring admission to hospital. [ 1 ] [ 2 ]


Causes of bowel obstruction include  adhesions ,  hernias ,  volvulus ,  endometriosis ,  inflammatory bowel disease ,  appendicitis ,  tumors ,  diverticulitis ,  ischemic bowel ,  tuberculosis  and  intussusception . [ 1 ] [ 2 ]  Small bowel obstructions are most often due to adhesions and hernias while large bowel obstructions are most often due to tumors and volvulus. [ 1 ] [ 2 ]  The diagnosis may be made on plain  X-rays ; however,  CT scan  is more accurate. [ 1 ]   Ultrasound  or  MRI  may help in the diagnosis of children or  pregnant  women. [ 1 ]


The condition may be treated conservatively or with  surgery . [ 2 ]  Typically  intravenous fluids  are given, a  nasogastric (NG) tube is placed through the nose into the stomach  to decompress the intestines, and  pain medications  are given. [ 2 ]   Antibiotics  are often given. [ 2 ]  In small bowel obstruction about 25% require surgery. [ 6 ]  Complications may include  sepsis , bowel  ischemia  and  bowel perforation . [ 1 ]


About 3.2 million cases of bowel obstruction occurred in 2015 which resulted in 264,000 deaths. [ 3 ] [ 7 ]  Both sexes are equally affected and the condition can occur at any age. [ 6 ]  Bowel obstruction has been documented throughout history, with cases detailed in the  Ebers Papyrus  of 1550 BC and by  Hippocrates . [ 8 ]


Depending on the level of obstruction, bowel obstruction can present with  abdominal pain ,  abdominal distension , and  constipation . Bowel obstruction may be complicated by  dehydration  and  electrolyte abnormalities  due to vomiting; respiratory compromise from pressure on the  diaphragm  by a distended abdomen, or  aspiration  of vomitus; bowel  ischemia  or  perforation  from prolonged distension or pressure from a foreign body and subsequently  sepsis  due to  bowel flora . [ 9 ]


In small bowel obstruction, the  pain  tends to be colicky (cramping and intermittent) in nature, with spasms lasting a few minutes. The pain tends to be central and mid-abdominal. Vomiting may occur before constipation. [ 10 ]  Common physical exam findings may include signs of  dehydration , abdominal distension with tympany, nonspecific abdominal tenderness, and high pitched tinkly bowel sounds. [ 11 ]


In large bowel obstruction, the pain is felt lower in the abdomen and the spasms last longer. Common symptoms include abdominal pain, distension, and severe constipation. [ 12 ]  Constipation occurs earlier and vomiting may be less prominent. Proximal obstruction of the large bowel may present as small bowel obstruction. [ 13 ]  Patients may notice a history of bloating and narrowing of stools before the onset of more severe symptoms. Symptoms can present quickly in the cases of  volvulus  and can present over a longer period of time in the setting of cancer. Common physical exam findings may include a palpable  hernia , abdominal distension with tympany, nonspecific lower abdominal tenderness, and a rectal mass. [ 6 ]


The main diagnostic tools are  blood tests ,  X-rays  of the abdomen, CT scanning, and  ultrasound . If a mass is identified,  biopsy  may determine the nature of the mass. [ citation needed ]


Radiological  signs of bowel obstruction include bowel distension (small bowel loops dilated >3 cm) and the presence of multiple (more than 2) air-fluid levels on supine and erect abdominal  radiographs . [ 16 ]  Ultrasounds may be as useful as CT scanning to make the diagnosis. [ 17 ]


Contrast enema  or small bowel series or CT scan can be used to define the level of obstruction, whether the obstruction is partial or complete, and to help define the cause of the obstruction. The appearance of water-soluble contrast in the cecum on an abdominal radiograph within 24 hours of it being given by mouth predicts resolution of an adhesive small bowel obstruction with  sensitivity  of 97% and  specificity  of 96%. [ 18 ]


Colonoscopy , small bowel investigation with ingested camera or push  endoscopy , and  laparoscopy  are other diagnostic options.


Differential diagnoses  of bowel obstruction include:


Causes of  small bowel  obstruction include: [ 2 ]


After abdominal surgery, the incidence of small bowel obstruction from any cause is 9%. In those where the cause of the obstruction was clear, adhesions are the single most common cause (more than half). [ 22 ]


Causes of large bowel obstruction include: [ 23 ]


Outlet obstruction is a sub-type of large bowel obstruction and refers to conditions affecting the anorectal region that obstruct  defecation , specifically conditions of the pelvic floor and anal sphincters. Outlet obstruction can be classified into four groups. [ 24 ]


Treatment of small and large bowel obstructions are initially similar and non-operative management is usually the initial management strategy as the majority of small bowel obstruction resolve spontaneously with non-operative management. [ 25 ] [ 26 ]  Patients are monitored by the surgical team for signs of improvement and resolution of the obstruction on imaging; if the obstruction does not clear then surgical management for the treatment of the causative lesion is required. [ 27 ]  In malignant large bowel obstruction, endoscopically placed self-expanding metal  stents  may be used to temporarily relieve the obstruction as a bridge to surgery, [ 28 ]  or as  palliation . [ 29 ]  Diagnosis of the type of bowel obstruction is normally conducted through initial plain  radiograph  of the abdomen, luminal contrast studies,  computed tomography scan , or  ultrasonography  prior to determining the best type of treatment. [ 30 ]


Further research is needed to find out if parenteral nutrition is of benefit to people with an inoperable blockage of the bowel caused by advanced cancer. [ 31 ]


In the management of small bowel obstructions, a commonly quoted surgical aphorism is: "never let the sun rise or set on small-bowel obstruction" [ 32 ]  because about 5.5% [ 32 ]  of small bowel obstructions are ultimately fatal if treatment is delayed. Improvements in radiological imaging of small bowel obstructions allow for confident distinction between simple obstructions, that can be treated conservatively, and obstructions that are surgical emergencies ( volvulus , closed-loop obstructions,  ischemic bowel , incarcerated  hernias , etc.). [ 2 ]  Exam findings of bowel compromise requiring immediate surgery include: severe abdominal pain, signs of  peritonitis  such as rebound tenderness,  elevated heart rate , fever, and elevated inflammatory markers on lab work, such as  lactic acid . [ 33 ] [ 34 ]


A small flexible tube ( nasogastric tube ) may be inserted through the nose into the stomach to help decompress the dilated bowel. This tube is uncomfortable but relieves the abdominal cramps, distention, and vomiting.  Intravenous therapy  is utilized and the urine output may be monitored with a  catheter  in the  bladder . [ 35 ] [ 36 ]


Most people with SBO are initially managed conservatively because in many cases, the bowel will open up. Some adhesions loosen up and the obstruction resolves. The patient is examined several times a day, and  X-ray images  are made to ensure he or she is not getting clinically worse. [ 37 ]


Conservative treatment involves insertion of a  nasogastric tube , correction of dehydration and  electrolyte  abnormalities.  Opioid  pain relievers may be used for patients with severe pain but alternate pain relievers are preferred as opioids can decrease bowel motility. [ 38 ] Antiemetics  may be administered if the patient is vomiting. Adhesive obstructions often settle without surgery. If the obstruction is complete surgery is usually required.


Most patients improve with conservative care in 2–5 days. When the obstruction is cancer, surgery is the only treatment. Those with  bowel resection  or  lysis  of adhesions usually stay in the hospital a few more days until they can eat and walk. [ 39 ]


Small bowel obstruction caused by  Crohn's disease , peritoneal  carcinomatosis , sclerosing  peritonitis ,  radiation enteritis , and postpartum bowel obstruction are typically treated conservatively, i.e. without surgery.


The prognosis for non-ischemic cases of SBO is good with mortality rates of 3–5%, while prognosis for SBO with ischemia is fair with mortality rates as high as 30%. [ 40 ]


Cases of SBO related to cancer are more complicated and require additional intervention to address the  malignancy , recurrence, and  metastasis , and thus are associated with a more poor prognosis. [ 41 ]  Surgical options in patients with malignant bowel obstruction need to be considered carefully as while it may provide relief of symptoms in the short term, there is a high risk of mortality and re-obstruction. [ 42 ]


All cases of abdominal surgical intervention are associated with increased risk of future small-bowel obstructions. Statistics from U.S. healthcare report 18.1% re-admittance rate within 30 days for patients who undergo SBO surgery. [ 43 ]  More than 90% of patients also form adhesions after major abdominal surgery. [ 44 ]
Common consequences of these adhesions include small-bowel obstruction, chronic abdominal pain, pelvic pain, and infertility. [ 44 ]


Endoscopic stenting  is a medical procedure by which a  stent , a hollow device designed to prevent constriction or collapse of a tubular organ, is inserted by  endoscopy . They are usually inserted when a disease process has led to narrowing or obstruction of the organ in question, such as the  esophagus  or the  colon .


There are various types of endoscopic stents: plastic stents, uncovered self-expandable metallic stents, partially covered self-expandable metallic stents, and fully covered self-expandable metallic stents. [ 1 ]   Self-expandable metallic stents  "play an important role in the management of malignant obstructing lesions in the gastrointestinal tract." [ 2 ]


A stent may be inserted into the  common bile duct  during an  endoscopic retrograde cholangiopancreatography , especially if  gallstone  removal is deemed too risky. [ 3 ]


Some complications of metallic stents are: stent migration (occurring in 20 to 40% of the cases). Stents with anchoring flaps or flared ends can reduce the risk of migration. Cholecystitis can be a complication for stenting of malignant biliary stricture. Stent occlusion may occur from tumor or tissue overgrowth, or due to sludge deposits, causing the development of cholangitis. [ 1 ]


In  medicine , a  distal splenorenal shunt procedure  ( DSRS ), also  splenorenal shunt procedure  and  Warren shunt , [ 1 ]  is a  surgical procedure  in which the  distal   splenic vein  (a part of the  portal venous system ) is attached to the left  renal vein  (a part of the  systemic venous system ).  It is used to treat  portal hypertension  and its main complication ( esophageal varices ). [ 2 ]  It was developed by  W. Dean Warren .


DSRS is typically done with splenopancreatic and gastric disconnection (ligation of the  gastric veins  and  pancreatic veins  (that drain into the  portal vein ) and complete detachment of the  splenic vein  from the  portal venous system ), as it improves the outcome. [ 3 ]


Survival with a  transjugular intrahepatic portosystemic shunt  (TIPS) versus a DSRS is thought to be approximately similar, [ 4 ] [ 5 ]  but still an area of intensive research. [ 6 ] [ 7 ]


Both TIPS and DSRS lead to decreased rates of  variceal bleeding  at the expense of  hepatic encephalopathy ; however, TIPS appears to have more shunt dysfunction and lead to more encephalopathy and bleeds. [ 5 ]  DSRS appears to be more cost effective than TIPS. [ 8 ]


An  epidural abscess  refers to a collection of pus and infectious material located in the  epidural space  superficial to the  dura mater  which surrounds the  central nervous system . Due to its location adjacent to brain or spinal cord, epidural abscesses have the potential to cause weakness, pain, and paralysis.


A  spinal epidural abscess  (SEA) is a collection of pus or inflammatory granulation between the  dura mater  and the  vertebral column . [ 1 ]   Currently the annual incidence rate of SEAs is estimated to be 2.5–3 per 10,000 hospital admissions.  Incidence of SEA is on the rise, due to factors such as an aging population, increase in use of invasive spinal instrumentation, growing number of patients with risk factors such as diabetes and intravenous drug use. [ 1 ]   SEAs are more common in posterior than anterior areas, [ 2 ]  and the most common location is the  thoracolumbar  area, where  epidural space  is larger and contains more fat tissue. [ 3 ]
SEAs are more common in males, and can occur in all ages, although highest prevalence is during the fifth and seventh decades of life. [ 1 ]


Combined treatment of emergency surgery and antibiotics is the preferred treatment for the spinal epidural abscess, removing existing pus (which is tested for microorganisms to select the most appropriate antibiotic) and removing pressure from the spinal cord and nerve roots. Antibiotic therapy should start after obtaining pus for microbiological investigation. [ citation needed ]


A  cranial epidural abscess  involves pus and granulation tissue accumulation in between the dura mater and cranial bone. These typically arise (along with  osteomyelitis  of a cranial bone) from infections of the ear or paranasal sinuses. They rarely can be caused by distant infection or an infected  cerebral venous sinus thrombosis .  Staphylococcus aureus  is the most common pathogen. Symptoms include pain at the forehead or ear, pus draining from the ear or sinuses, tenderness overlying the infectious site, fever, neck stiffness, and in rare cases focal seizures.  Treatment requires a combination of antibiotics and surgical removal of infected bone. [ 4 ]


article/232570  at  eMedicine


A  gastrojejunocolic fistula  is a disorder of the human  gastrointestinal tract . It may form between the transverse colon and the upper  jejunum  after a  Billroth II  surgical procedure.  (The Billroth procedure attaches the jejunum to the remainder of the stomach.) Fecal matter thereby passes improperly from the colon to the stomach, and causes  halitosis . [ citation needed ]


Patients may present with  diarrhea , [ 1 ]   weight loss  and  halitosis  as a result of fecal matter passing through the  fistula  from the colon into the stomach.


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


A  glomectomy  is an excision of a  glomus body  or a  glomus cell , usually in the case of a  glomus tumor . This operation was formerly performed for the treatment of severe, chronic  asthma , [ 1 ]  but has since been abandoned for this purpose due to its lack of efficacy. [ 2 ] [ 3 ]


In  human anatomy , the  greater sac , also known as the  general cavity (of the abdomen)  or  peritoneum of the  peritoneal cavity  proper , is the cavity in the  abdomen  that is inside the peritoneum but outside the  lesser sac .


It is connected with the lesser sac via the  omental foramen , also known as the  foramen of Winslow  or  epiploic foramen , which is anteriorly bounded by the portal triad –  portal vein ,  hepatic artery , and  common bile duct .


The  ileojejunal bypass  is an  experimental   surgery  designed as a remedy for  morbid obesity . [ 1 ] [ 2 ]


It was first performed on a series of patients at White Memorial Hospital,  Los Angeles, California , in the mid-to-late 1970s. It has since been discarded, as the complications from the surgery, including malnutrition, vitamin deficiencies, protein and albumin deficiency, liver and renal failure, and kidney stones, highly outweighed the benefits. Many patients who received this surgery consequently underwent reversal surgery.


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


Intra-abdominal infection  ( IAI , also spelled  intraabdominal ) is a group of  infections  that occur within the  abdominal cavity . They vary from  appendicitis  to  fecal peritonitis . [ 1 ]  Risk of death despite treatment is often high. [ 1 ]


IAIs can be classified into uncomplicated and complicated infections. Uncomplicated infections often involved the infection of single organ and can be controlled by surgical removal of the source of infection, and antibiotics is not required after the surgery to control the infection. In complicated infections, the infection spread to a part or to the whole of the  peritoneum , causing  peritonitis . Meanwhile, peritonitis can be classified into primary, secondary, and tertiary peritonitis. Primary peritonitis is the diffuse bacterial infection of the peritoneum while the integrity of the gastrointestinal tract is preserved (in cases of  ascites ); secondary peritonitis is the infection of peritoneum where the integrity of gastrointestinal tract is compromised; tertiary peritonitis is reinfection of peritoneum 48 hours after apparently good surgical control of secondary peritonitis. [ 2 ]


Those with suspected with IAIs usually have acute onset of abdominal pain with signs of local or generalised  inflammations  such as pain,  tenderness  (pain on touching), fever,  tachycardia  (increased heart rate), or  tachypnea  (increased breathing rate). In more severe cases, such as organ failure, signs such as  hypotension  (low blood pressure),  oliguria  (reduced urine output), sudden onset of  altered level of consciousness , and  lactic acidosis  will appear. [ 2 ]


In case of  appendicitis , signs such as fever, positive  psoas sign , migration of pain from umbilicus to the  right iliac fossa  increases the likelihood of the disease; while signs such as vomiting before the pain reduces its likelihood to occur. [ 2 ]


CT scan and ultrasound has been used routinely to complete the assessment of IAIs. CT scan has higher sensitivity and specificity than ultrasound to access the condition. However, CT scan poses radiation risk to the subject. [ 2 ]  MRI scan is less readily available than CT scan or ultrasound in hospitals to diagnose IAIs. However, it has been proposed to be used in those who are pregnant and have inconclusive findings on ultrasound. The sensitivity and specificity of MRI in diagnosing acute appendicitis are 94% and 96% respectively. [ 2 ]


Laparoscopic surgery has also been used to diagnose the cause of IAIs when imaging is unhelpful. Besides, the laparoscopic surgery can also initiate treatment in the same setting. The accuracy is very high, in the range of 86 to 100%. [ 2 ]


The  lesser sac , also known as the  omental bursa , is a part of the  peritoneal cavity  that is formed by the  lesser  and  greater omentum .  Usually found in mammals, it is connected with the  greater sac  via the  omental foramen  or  Foramen of Winslow . In mammals, it is common for the lesser sac to contain considerable amounts of fat.


If any of the marginal structures rupture their contents could leak into the lesser sac. If the stomach were to rupture on its anterior side though the leak would collect in the  greater sac . [ citation needed ]


The lesser sac is formed during  embryogenesis  from an infolding of the greater omentum. The open end of the infolding, known as the  omental foramen  is usually close to the stomach. [ citation needed ]


A  lower anterior resection , formally known as  anterior resection of the rectum and colon  and  anterior excision of the rectum  or simply  anterior resection  (less precise), is a common surgery for  rectal cancer  and occasionally is performed to remove a diseased or ruptured portion of the intestine in cases of  diverticulitis . It is commonly  abbreviated  as  LAR . [ citation needed ]


LARs are for cancer in the  proximal  (upper) two-thirds of the rectum which lends itself well to resection while leaving the rectal sphincter intact. [ 1 ]


LARs, generally, give a better  quality of life  than  abdominoperineal resections  (APRs). [ 2 ] [ 3 ]  Thus, LARs are generally the preferred treatment for rectal cancer insofar as this is surgically feasible. APRs lead to a permanent colostomy and do not spare the sphincters. [ citation needed ]


Low anterior resection syndrome (LARS) comprises a collection of symptoms mainly affecting patients after surgery for rectal cancer characterized by fecal incontinence (stool and gases), fecal urgency, frequent bowel movements and bowel fragmentation, while some patients only experience constipation and a  feeling of incomplete bowel emptying . [ 4 ] [ 5 ] [ 6 ]    The cause is unclear, and has been thought to be due to nerve damage, or possibly due to loss of the  rectoanal inhibitory reflex. [ 5 ]


Many of the symptoms of LAR syndrome improve over a period of many months. [ 7 ]  The nerves that control the natural contractions of the colon and rectum run along the colon and can be damaged or cut during the surgery. [ citation needed ]   After such damage, the nerves can regrow, but only slowly.


Digestive system surgery , or  gastrointestinal surgery , can be divided into upper GI surgery and lower GI surgery. [ 1 ]


Upper gastrointestinal surgery , often referred to as  upper GI surgery , refers to a practice of  surgery  that focuses on the upper parts of the  gastrointestinal tract . There are many operations relevant to the upper gastrointestinal tract that are best done only by those who keep constant practice, owing to their complexity. Consequently, a  general surgeon  may specialise in 'upper GI' by attempting to maintain currency in those skills.


Upper GI surgeons would have an interest in, and may exclusively perform, the following operations:


Surgery on the digestive system's organs is referred to as digestive system surgery, gastrointestinal surgery, or gastrointestinal (GI) surgery. Nutrients from the food we eat are processed and absorbed by the digestive system. Surgery could be required to remedy or treat certain problems or diseases that affect the digestive tract.


There are many different types of digestive system operations, some of the more popular ones being:
1. Appendectomy: The surgical removal of the appendix, typically as a result of acute appendicitis, an appendix inflammation.
2. Gastric bypass: A weight-loss procedure that includes separating the stomach into an upper pouch that is smaller and a lower pouch that is bigger. Then, a section of the stomach and small intestine are skipped in favor of rearranging the small intestine to link to both pouches. As a result, the stomach can contain less food and nutrients are not as well absorbed, which causes weight loss.
3. Cholecystectomy: Surgically removing the gallbladder, frequently as a result of painful gallstones or other problems.
4. Colectomy: The removal of the colon (large intestine) whole or in part. This procedure is typically done to address problems including colorectal cancer, diverticular disease, or inflammatory bowel disease.
5. Resection of the liver in part: This procedure is frequently carried out to treat liver tumors or to remove damaged liver tissue.
6. Esophagectomy: Removal of the esophagus in whole or in part, usually to treat esophageal cancer.
7. Pancreatic Surgery: procedures involving the pancreas, such as the Whipple surgery (pancreaticoduodenectomy), which is used to treat some forms of pancreatic cancer and other serious pancreatic diseases.
8. Hernia Repair: A hernia, which is the protrusion of an organ or tissue through a weak spot in the abdominal wall, is treated surgically.


These operations can be carried out using conventional open surgical procedures or minimally invasive techniques like laparoscopic or robotic-assisted surgery, which require smaller incisions and result in quicker recoveries. Surgery of the digestive system is a complicated topic that calls for specialized education and experience. To make educated decisions regarding their healthcare, individuals must speak with a trained surgeon about their unique situation, treatment options, and potential hazards.


A  Meckel's diverticulum , a true  congenital   diverticulum , is a slight bulge in the  small intestine  present at birth and a  vestigial  remnant of the  vitelline duct . It is the most common malformation of the  gastrointestinal tract  and is present in approximately 2% of the population, [ 1 ]  with males more frequently experiencing symptoms.


Meckel's diverticulum was first explained by  Fabricius Hildanus  in the sixteenth century and later named after  Johann Friedrich Meckel , who described the embryological origin of this type of diverticulum in 1809. [ 2 ] [ 3 ]


The majority of people with a Meckel's diverticulum are  asymptomatic . An asymptomatic Meckel's diverticulum is called a  silent  Meckel's diverticulum. [ 4 ]  If symptoms do occur, they typically appear before the age of two years. [ 5 ]  The most common presenting symptom is painless  rectal bleeding  such as  melaena -like black offensive stools, followed by  intestinal obstruction ,  volvulus  and  intussusception . Occasionally, Meckel's diverticulitis may present with all the features of  acute appendicitis . [ 6 ]  Also, severe pain in the  epigastric region  is experienced by the person along with bloating in the epigastric and umbilical regions. At times, the symptoms are so painful that they may cause sleepless nights with acute pain felt in the foregut region, specifically in the  epigastric  and  umbilical  regions. [ citation needed ]  In some cases, bleeding occurs without warning and may stop spontaneously. The symptoms can be extremely painful, often mistaken as just stomach pain resulting from not eating or constipation. [ citation needed ]  Rarely, a Meckel's diverticulum containing ectopic pancreatic tissue can present with abdominal pain and increased serum amylase levels, mimicking acute pancreatitis. [ 7 ]


The lifetime risk for a person with Meckel's diverticulum to develop certain  complications  is about 4–6%. Gastrointestinal bleeding,  peritonitis  or  intestinal obstruction  may occur in 15–30% of symptomatic people (Table 1). On rare occasions the diverticulum can herniate through the abdominal wall also known as a  Littre hernia.  Only 6.4% of all complications require surgical treatment, and untreated Meckel's diverticulum has a  mortality rate  of 2.5–15%. [ 8 ]


Table 1 – Complications of Meckel's Diverticulum: [ 9 ]


Bleeding of the diverticulum is most common in young children, especially in males who are less than 2 years of age. [ 10 ]  Symptoms may include bright red blood in stools ( hematochezia ), weakness, abdominal tenderness or pain, and even  anaemia  in some cases. [ 11 ]


Bleeding may be caused by:


The appearance of stools may indicate the nature of the bleeding:


Inflammation of the diverticulum can mimic symptoms of appendicitis, i.e., periumbilical tenderness and intermittent crampy abdominal pain. Perforation of the inflamed diverticulum can result in peritonitis. Diverticulitis can also cause  adhesions , leading to intestinal obstruction. [ 14 ]


Diverticulitis may result from:


Symptoms:  Vomiting, abdominal pain and severe or complete  constipation . [ 18 ]


Anomalies between the diverticulum and umbilicus may include the presence of a fibrous cord,  cyst , fistula, or sinus, leading to: [ 14 ]


Neoplasms  (tumors) in Meckel's diverticulum may cause bleeding, acute abdominal pain, gastrointestinal obstruction, perforation or intussusception. They may be  benign  or  malignant . [ 14 ]


The omphalomesenteric duct (omphaloenteric duct, vitelline duct, or yolk stalk) normally connects the embryonic midgut to the yolk sac ventrally, providing nutrients to the midgut during embryonic development. The vitelline duct narrows progressively and disappears between the 5th and 8th weeks of gestation. [ citation needed ]


In Meckel's diverticulum, the proximal part of vitelline duct fails to regress and involute, which remains as a remnant of variable length and location. [ 16 ]  The solitary diverticulum lies on the antimesenteric border of the ileum (opposite to the  mesenteric attachment ) and extends into the umbilical cord of the embryo. [ 8 ]  The left and right vitelline arteries originate from the primitive  dorsal aorta , and travel with the vitelline duct. The right becomes the  superior mesenteric artery  that supplies a terminal branch to the diverticulum, while the left involutes. [ 17 ]  Having its own blood supply, Meckel's diverticulum is susceptible to obstruction or infection.


Meckel's diverticulum is located in the  distal   ileum , usually within 60–100 cm (2 feet) of the  ileocecal valve . This  blind segment  or small pouch is about 3–6 cm (2 inch) long and may have a greater  lumen  diameter than that of the  ileum . [ 20 ]  It runs antimesenterically and has its own blood supply. It is a remnant of the connection from the  yolk sac  to the small intestine present during  embryonic development . It is a  true diverticulum , consisting of all three layers of the  bowel  wall:  mucosa ,  submucosa  and  muscularis propria . [ 17 ]


As the vitelline duct is made up of  pluripotent  cell lining, Meckel's diverticulum may harbor abnormal tissues, containing embryonic remnants of other tissue types.  Jejunal ,  duodenal  mucosa or  Brunner's tissue  were each found in 2% of  ectopic  cases.  Heterotopic  rests of  gastric  mucosa and  pancreatic  tissue are seen in 60% and 6% of cases respectively. Heterotopic means the displacement of an organ from its normal anatomic location. [ 21 ]  Inflammation of this Meckel's diverticulum may mimic appendicitis. Therefore, during appendectomy, ileum should be checked for the presence of Meckel's diverticulum, if it is found to be present it should be removed along with appendix. [ citation needed ]


A  memory aid  is the rule of 2s: [ 22 ]


However, the exact values for the above criteria range from 0.2–5 (for example, prevalence is probably 0.2–4%). [ citation needed ]