APPENDICITIS

ACUTE APPENDICITIS
Acute appendicitis is one of the most common causes of an abdominal emergency and accounts for approximately 1% of all surgical operations.
• Although rare in infants, appendicitis becomes increasingly common throughout childhood and reaches its maximal incidence between the ages of 10 and 30 years.
• After 30 years of age, the incidence declines, but appendicitis can occur in individuals of any age.
• Among teenagers and young adults, the male/female ratio is about 3:2.
• After age 25 years, the ratio gradually declines until the sex ratio is equal by the mid 30s.
Pathophysiology
The most commonly accepted theory of the pathogenesis of appendicitis is that it results from obstruction followed by infection.
• The lumen of the appendix becomes obstructed by hyperplasia of submucosal lymphoid follicles, a fecalith, stricture, tumor, or other pathologic condition.
• Once the lumen of the appendix is obstructed, the sequence of events leading to acute appendicitis is probably as follows.
o Mucus accumulates within the lumen of the appendix, and pressure within the organ increases.
o Virulent bacteria convert the accumulated mucus into pus.
o Continued secretion combined with the relative inelasticity of the serosa leads to a further rise in pressure within the lumen.
o This results in obstruction of the lymphatic drainage, leading to edema of the appendix, diapedesis of bacteria, and the appearance of mucosal ulcers.
o At this stage, the disease is still localized to the appendix; therefore, the pain perceived by the patient is visceral and is localized to the epigastrium or periumbilical area.
o This pain usually is accompanied by anorexia, nausea, and, on occasion, vomiting.
o Continued secretion into the lumen and increasing edema bring about a further rise in intraluminal and tissue pressure, resulting in venous obstruction and ischemia of the appendix.
o Bacteria spread through the wall of the appendix, and acute suppurative appendicitis ensues.
o Somatic pain occurs when the inflamed serosa of the appendix comes in contact with the parietal peritoneum and results in the classic shift of pain to the right lower quadrant.
o As this pathologic process continues, venous and arterial thromboses occur in the wall of the appendix, resulting in gangrenous appendicitis.
o At this stage, small infarcts occur, permitting escape of bacteria and contamination of the peritoneal cavity.
o The final stage in the progression of acute appendicitis is perforation through a gangrenous infarct and the spilling of accumulated pus. Perforating appendicitis is now present, and morbidity and mortality increase.
Symptoms
The symptomatic history in acute appendicitis may vary, but cardinal symptoms are usually present.
The history usually begins with abdominal pain often localized to the epigastrium or the periumbilical area, followed by anorexia and nausea. Vomiting, if it occurs, appears next. After a variable period, usually about 8 hours, the pain shifts to the right side and usually into the right lower quadrant. At the time of presentation, the duration of pain is less than 24 hours in 75% of patients.
Pain.
The typical pain of acute appendicitis initially consists of diffuse, central, minimally severe visceral pain, which is followed by somatic pain that is more severe and usually well localized to the right lower quadrant.
o Failure to follow the classic visceral-somatic sequence is common in acute appendicitis, occurring in up to 45% of patients who are proved subsequently to have appendicitis.
o Atypical pain may be somatic and localized to the right lower quadrant from its initiation.
o Conversely, the pain may remain diffuse and may never become localized. In older patients, atypical pain patterns occur more frequently.
Patients with high retrocecal appendicitis
o may present with only diffuse pain in the right flank.
Similarly, patients in whom the entire appendix is within the true pelvis
o may never experience somatic pain and, instead,
o may have tenesmus and vague discomfort in the suprapubic area.
Anorexia, Nausea, and Vomiting.
o Anorexia and nausea are present in almost all patients with acute appendicitis but
o vomiting occurs in fewer than 50% of patients.
o The presence or absence of vomiting is not a criterion for the diagnosis of appendicitis.
o When vomiting does occur, it is usually not persistent, and most patients vomit only once or twice.
o If vomiting occurs, it occurs after the onset of pain with such regularity that if it precedes pain, the diagnosis of appendicitis should be questioned.
Constipation and Diarrhea.
A history of the recent onset of constipation or diarrhea is not very helpful in the diagnosis of appendicitis. A greater percentage of patients with appendicitis complain of constipation, but some give a history that defecation relieves the pain.
Physical Examination
Tenderness and Muscle Guarding.
On routine abdominal examination, an area of maximal tenderness often will be elicited in the area of McBurney's point, which is located two thirds of the distance along a line from the umbilicus to the right anterior superior iliac spine.
o It should be remembered that if the appendix is in a high retrocecal position or is entirely within the true pelvis, point tenderness and muscle rigidity might not be elicited.
o In high retrocecal appendicitis, tenderness may occur over a large area, and there may be no signs of muscle rigidity.
o In pelvic appendicitis, neither tenderness nor muscle guarding may be present. Both signs are often lacking or only minimally expressed in the aged population.
Signs of peritoneal inflammation or irritation in the right lower quadrant are also helpful in the diagnosis of acute appendicitis and can be demonstrated by many methods.
o Asking the patient to cough or bounce on the heels will elicit this type of pain in 85% of patients.
o Rebound tenderness is elicited by the sudden release of abdominal palpation pressure.
o Rovsing's sign—pain elicited in the right lower quadrant with palpation pressure in the left lower quadrant—is a sign of acute appendicitis.
o Muscle guarding, manifested as resistance to palpation, increases as the severity of inflammation of the parietal peritoneum increases.
o Initially, there is only voluntary guarding, but this is replaced by reflex involuntary rigidity.
Abdominal Mass.
As the disease process progresses, it may be possible to palpate a tender mass in the right lower quadrant.
o Although the mass may be caused by an abscess, it can also result from adherence of the omentum and loops of intestine to an inflamed appendix.
o When appendicitis becomes advanced enough that there is a large, inflamed mass and the anterior abdominal wall is involved, the patient often avoids sudden movements that can cause pain.
Psoas Sign.
o The right hip is often kept in slight flexion to keep the iliopsoas muscle relaxed.
o Stretching the muscle by extension of the hip or further flexion against resistance can initiate a positive psoas sign, indicating irritation of the muscle by an inflamed appendix.
o A psoas sign is seldom seen in early appendicitis and interestingly can be elicited in patients without any pathologic condition.
Rectal Examination.
Rectal examination, although essential in all patients with suspected appendicitis, is helpful in only a few of them.
o In patients with an uncomplicated appendicitis, the finger of the examiner cannot reach high enough to elicit pain on rectal examination.
If the appendix ruptures, the physical examination will change.
o If the infection is contained, a soft, tender mass will often develop in the right lower quadrant, and the area of tenderness will now encompass the entire right lower quadrant.
o Involuntary guarding will become evident and rebound tenderness more marked. The patient's temperature will be more like that seen with abscess formation and may rise to 39° C with a corresponding tachycardia.
If appendiceal rupture fails to localize, signs and symptoms of diffuse peritonitis will develop.
o Tenderness and guarding will become generalized, the temperature will remain higher than 38° C with spikes to 40° C, and the pulse rate will increase to more than 100 beats/min.
Laboratory Tests
In the early diagnosis of acute appendicitis, laboratory tests are of little value.
o Up to one third of patients, particularly older patients, will have a normal total leukocyte count with acute appendicitis,
o and more than half will have, at most, a mild elevation.
o Even when the total leukocyte count and the differential white cell count are abnormal, the degree of abnormality does not correlate well with the degree of appendiceal inflammation.
o Even when the total white cell count is normal, the differential white cell count often reveals a shift to the left with an increase in the percentage of polymorphonuclear neutrophils.
o Less than 4% of patients will have both a normal total white cell count and a normal differential count.
o The most important fact to remember when considering the diagnosis of appendicitis is that the clinical findings take precedence over the white cell count when they are at variance.
Inflammatory markers have been introduced as potential markers for acute appendicitis. C-reactive protein (CRP) in combination with WBC and differential count have been helpful in a few studies in improving diagnostic accuracy.
Urinalysis is helpful in the differential diagnosis of patients with lower abdominal pain only when it reveals significant numbers of red cells, white cells, or bacteria.
o Minimal numbers of red cells, white cells, and bacteria are seen in normal patients as well as in patients with appendicitis.
Patients with advanced appendicitis and abscess formation or generalized peritonitis may have abnormalities in liver function tests that mimic obstructive jaundice, biliary stasis, or other primary liver problems.
X-Ray Examination
With rare exceptions, plain roentgenologic examination of the abdomen is of little help in the differential diagnosis of acute appendicitis.
o The exceptions are when a fecalith is demonstrated and when other diagnoses—such as acute cholecystitis, perforating duodenal ulcer, perforating colon cancer, acute diverticulitis, and pyelonephritis—are being excluded.
o It is not unusual to see cecal distention or a sentinel loop of distended small intestine in the right lower quadrant in patients with acute appendicitis.
o In late appendicitis with perforation and abscess formation, a mass can often be demonstrated that is extrinsic to the cecum.
o There may be scoliosis to the right, lack of the right psoas shadow, lack of small bowel gas in the right lower quadrant with abundant gas elsewhere in the small bowel, and signs of edema of the abdominal wall.
o With late appendicitis and generalized peritonitis, there will be an ileus pattern with generalized gas throughout the small and large intestine.
Barium enema (BE) examination was recommended in the past in young women in whom the diagnosis was still in question after hours of observation and in patients with a debilitating systemic disease, such as leukemia, in whom the operative risk is markedly increased.
The findings of significance on BE include
o lack of filling or partial filling of the appendix and an extrinsic pressure defect on the cecum (the "reverse 3" sign).
As demonstrated in many studies, an experienced radiologist is able to diagnose acute appendicitis using US with an accuracy of greater than 90%.
o Appendicitis is diagnosed
o if the maximal cross-sectional diameter of appendix exceeds 6 mm,
o if it is noncompressible,
o if an appendolith is present, or
o if a complex mass is demonstrated.
Although more expensive, CT has also been demonstrated to be of benefit in the diagnosis of acute appendicitis and has an accuracy of greater than 90%.
The cost can be reduced with no significant loss in diagnostic accuracy by performing a limited, unenhanced CT.
o Appendicitis is diagnosed when the appendix is thickened with
o a diameter greater than 6 mm,
o a phlegmon,
o fluid,
o or abscess is present,
o there is an appendolith,
o and there are inflammatory changes in the periappendiceal fat (streaking and poorly defined increased attenuation).
CT is not indicated in patients with an unequivocal diagnosis of appendicitis or in patients with a low risk of the diagnosis.
o In menstruating women and any patient with an equivocal diagnosis, a CT scan is probably indicated.
o An added benefit of the use of CT is that an identified abscess can be percutaneously drained during the same procedure.
Improved radionuclide imaging techniques with radiolabeled autologous leukocytes have been developed that have a high sensitivity and specificity in the diagnosis of appendicitis
Acute Appendicitis in Infants and Young Children
The diagnosis of acute appendicitis is difficult in infants and young children for many reasons. The patient is unable to give an accurate history, and although appendicitis is infrequent, acute nonspecific abdominal pain is common in infants and children. Because of such factors, the diagnosis and treatment are often delayed, and complications develop.
The clinical presentation of appendicitis in children can be very similar to nonspecific gastroenteritis; thus, the suspicion of appendicitis often is not aroused until the appendix has ruptured and the child is obviously ill. Two thirds of young children with appendicitis have had symptoms for more than 3 days before appendectomy.
o Vomiting, fever, irritability, flexing of the thighs, and diarrhea are likely early complaints.
o Abdominal distention is the most consistent physical finding.
o As in adults, the total leukocyte count is not a reliable test.
The incidence of perforation in infants less than 1 year of age is almost 100%, and although it decreases with age, it is still 50% at 5 years of age.
o The mortality rate in this age group remains as high as 5%.
o In one series, nearly 40% of children with complicated appendicitis had been seen previously by a physician who failed to make the diagnosis of appendicitis.
Appendicitis in Young Women
Although the overall incidence of negative laparotomy in patients suspected of having appendicitis is as high as 20%, the incidence in women less than 30 years of age is as high as 45%.
o Pain associated with ovulation; diseases of the ovaries, fallopian tubes, and uterus; and urinary tract infections (cystitis) account for the majority of the misdiagnoses.
o If a young woman has atypical pain; no muscular guarding in the right lower quadrant; and no fever, leukocystosis, or leftward shift in the differential white cell count, it is best to observe the patient with frequent re-examinations.
o If after several hours the patient's signs and symptoms remain stable, it is appropriate to perform a CT scan.
Appendicitis During Pregnancy
o The risk of appendicitis during pregnancy is the same as it is in nonpregnant women of the same age; the incidence is 1 in 2,000 pregnancies.
o Appendicitis occurs more frequently during the first two trimesters, and during this time period the symptoms of appendicitis are similar to those seen in nonpregnant women.
o Surgery should be performed during pregnancy when appendicitis is suspected, just as it would be in a nonpregnant woman.
o As in the nonpregnant patient, the effects of a laparotomy that produces no findings are minor, whereas the effects of a ruptured appendicitis can be catastrophic.
During the third trimester of pregnancy,
o the cecum and appendix are displaced laterally and are rotated by the enlarged uterus.
o This results in localization of pain either more cephalad or laterally in the flank, leading to delay in diagnosis and an increased incidence of perforation.
o Factors such as displacement of the omentum by the uterus also impair localization of the inflamed appendix and result in diffuse peritonitis.
o In cases of uncomplicated appendicitis, the prognosis for the infant following appendectomy is directly related to the infant's birth weight.
o If peritonitis and sepsis ensue, infant mortality increases because of prematurity and the effects of sepsis.
Acute appendicitis can be confused with pyelitis and torsion of an ovarian cyst. However, it must be remembered that death from appendicitis during pregnancy is mainly caused by a delay in diagnosis. In the final analysis, early appendectomy is the appropriate therapy in suspected appendicitis during all stages of pregnancy.
Appendicitis in the Elderly Population
Appendicitis has a much greater mortality rate among elderly persons when compared with young adults. The increased risk of mortality appears to result from both delay in seeking medical care and delay in making the diagnosis.
o Right lower quadrant pain localizes later and may be milder in elderly persons.
o On initial physical examination, the findings are often minimal, although right lower quadrant tenderness will eventually be present in most patients.
o Distention of the abdomen and a clinical picture suggesting small bowel obstruction are commonly seen.
o More than 30% of elderly patients will have a ruptured appendix at the time of operation.
o It is imperative, therefore, that once the diagnosis of acute appendicitis is made, an urgent operation must be advised.
Differential Diagnosis
When the classic symptoms of appendicitis are present, the diagnosis of appendicitis is usually easily made and is seldom missed.
o When the diagnosis is not obvious, knowledge of the differential diagnosis becomes very important. Most of the entities in the differential diagnosis of appendicitis also require operative therapy or are usually not made worse by an exploratory laparotomy.
o Therefore, it is essential that one eliminate those diseases that do not require operative therapy and can be made worse by operation; for example, pancreatitis, myocardial infarction, and basilar pneumonia.
The diseases in young children that are most frequently mistaken for acute appendicitis are
o gastroenteritis,
o mesenteric lymphadenitis,
o Meckel's diverticulum,
o pyelitis,
o small-intestinal intussusception,
o enteric duplication,
o and basilar pneumonia.
o In mesenteric lymphadenitis, an upper respiratory infection is often present or has recently subsided.
o Acute gastroenteritis is usually associated with crampy abdominal pain and watery diarrhea.
o Intestinal intussusception occurs most frequently in children younger than the age of 2 years, an age at which appendicitis is uncommon.
o With intussusception, a sausage-shaped mass is frequently palpable in the right lower quadrant.
o The preferred diagnostic procedure is a gentle BE, which, in addition to making the diagnosis, will usually reduce the intussusception.
In young women, the differential diagnosis includes
o ruptured ectopic pregnancy,
o mittelschmerz,
o endometriosis, and
o salpingitis.[6]
o Chronic constipation also needs to be considered in young women.
o The symptoms that accompany the acute onset of regional enteritis can mimic acute appendicitis, but a history of cramps and diarrhea, and the lack of an appropriate history for appendicitis, are hints that the diagnosis is regional enteritis.
In young men, the potential list of differential diagnoses is smaller and includes the
o acute onset of regional enteritis,
o right-sided renal or ureteral calculus,
o torsion of the testes,
o and acute epididymitis.
In older patients, the differential diagnosis of acute appendicitis includes
o diverticulitis,
o a perforated peptic ulcer,
o acute cholecystitis,
o acute pancreatitis,
o intestinal obstruction,
o perforated cecal carcinoma,
o mesenteric vascular occlusion,
o rupturing aortic aneurysm,
o and the disease entities already mentioned for young adults.
Treatment
Preoperative Preparation.
All patients, especially those with a presumed diagnosis of peritonitis, should be adequately prepared before being taken to the operating room. It should be remembered that selected patients with a palpable right lower quadrant mass may be initially managed without operation.
• Intravenous fluid replacement should be initiated and the patient resuscitated as rapidly as possible, especially when peritonitis is suspected.
• Once the patient has a good urinary output, it can be assumed that resuscitation is complete.
• Nasogastric suction is especially helpful in patients with peritonitis and profound ileus.
• f the patient's body temperature is higher than 39° C, appropriate measures should be taken to reduce fever prior to beginning an operation.
• A broad-spectrum antibiotic, such as cefoxitin, should be administered preoperatively to help control sepsis and to reduce the incidence of postoperative wound infections.
• If, at the time of operation, the patient has early appendicitis, antibiotic administration can be stopped after one postoperative dose.
• Antibiotics should be continued as clinically indicated in patients who have gangrenous or ruptured appendicitis with localized or generalized peritonitis.
Examination Under Anesthesia.
After the induction of anesthesia, the patient's abdomen should be systematically palpated. Such an examination may, on occasion, demonstrate another pathologic condition to be the cause of the patient's symptoms, such as acute cholecystitis. It also may be possible to palpate an appendiceal mass that will confirm the suspected diagnosis.
Uncomplicated Appendicitis Without a Palpable Mass.
• In this circumstance, when the diagnosis of acute appendicitis has been made and there is no reason to suspect that the appendix has ruptured, an appendectomy should be performed.
• As stated earlier, if there is any doubt about whether the appendix has ruptured, the operation should be performed at once, because the morbidity of a perforated appendix is much greater (100-fold greater) than that of an uncomplicated appendectomy.
• The latter procedure should have a surgical mortality rate of less than 0.1%, whereas in contrast, the mortality rate of a ruptured appendix can be as high as 10%.
o One recommended incision for a routine appendectomy is a transverse incision (Rockey-Davis incision, Fowler-Weir-Mitchell incision). The incision is made in a transverse direction, 1 to 3 cm below the umbilicus, and is centered on the midclavicular line. Exposure of the appendix through this incision is better when compared with that obtained through the classic McBurney's incision, particularly in patients with a retrocecal appendix and in those who are obese.
o The other recommended incision, the gridiron, or muscle-splitting incision (McBurney's incision), can be used. This is the most widely used incision in uncomplicated appendicitis. The skin incision is made through a point one third of the way along a line from the anterior superior spine of the ileum to the umbilicus. The incision is made obliquely, beginning inferiorly and medially, and extending laterally and superiorly.
o The exposure through a McBurney incision, especially for a retrocecal appendix, can be awkward unless the appendix lies immediately below the incision. If necessary, the incision can be extended medially, partially transecting the rectus sheath, but this maneuver is usually helpful only in a pelvic appendicitis.
o If there is doubt about the diagnosis of acute appendicitis and an exploratory laparotomy is indicated, a vertical midline incision is more appropriate.
o An appendectomy can be performed with little difficulty through such an incision,
o and if an appendiceal mass is encountered, the midline incision can be closed and a more direct approach can be made through another incision.
Once the appendix has been freed up, the mesoappendix is transected beginning at its free border, taking small bites of the mesoappendix between pairs of hemostats placed approximately 1 cm from and parallel to the appendix. This process should be repeated until the base of the appendix is reached. If exposure of a long, adherent appendix is difficult, the mesoappendix can be transected in a retrograde manner beginning at the base of the appendix.
The combination of ligation and inversion is not recommended, because it does not reduce the risk of septic complications, but it does create conditions conducive to the development of an intramural abscess or mucocele.
• Simple ligature of the appendiceal stump is accomplished by crushing the appendix at its base with a hemostat, then moving the hemostat and replacing it on the appendix just distal to the crushed line.
• A ligature of monofilament suture is placed in the groove caused by the crushing clamp and is tied tightly.
• The appendix is transected just proximal to the hemostat and removed. Inversion of an unligated stump using a Z stitch, rather than the more conventional purse-string suture, is preferred.
• The upper level of the Z stitch is placed as a Lembert suture in the cecum, just distal to the base of the appendix.
• If the appendiceal stump is unsuitable for inversion because of edema, it should simply be ligated and not inverted.
Laparoscopic Appendectomy.
Laparoscopic and minimal access surgery continue to expand in the field of general surgery, and diagnostic laparoscopy and laparoscopic appendectomy have become accepted procedures in many surgeons' practices.
• The early use of diagnostic laparoscopy in patients with right lower quadrant abdominal pain and suspected appendicitis will reduce the risk of appendiceal perforation and the negative appendectomy rate to less than 10%.
• Diagnostic laparoscopy is particularly useful in women of reproductive age and in the obese.
• In the former, frequently confounding gynecologic disorders can be well visualized to provide the diagnosis, and in the latter, laparoscopy can eliminate the morbidity risks of a large incision.
• In addition, it is safe to not proceed with appendectomy if the appendix appears normal.
• Needlescopic technology should be avoided because the optics do not provide adequate images of the appendix.
Trocar placement for laparoscopic appendectomy is a matter of surgeon choice with consideration of the triangle rule for port placement.
• Diagnostic laparoscopy is usually performed through a periumbilical port, with a 10/11-mm port added midway between the umbilicus and pubis and a 5-mm port placed over the appendix or the right midlateral abdomen if appendectomy is performed.
• Once the diagnosis is confirmed, the mesoappendix can be taken down with either hemoclips or the harmonic scalpel.
• The appendix is amputated from the cecum between endoloops or with an endo-GIA stapler.
• The appendix can then be removed from the abdomen with a specimen pouch or withdrawn into the 10/11-mm port.
• Care should be taken to prevent contact of the appendix or its contents with the wound edges.
• There is general agreement that patients undergoing laparoscopic appendectomy will have less postoperative pain, a more rapid return to diet, a shorter hospital stay, a longer operative time, and more equipment charges in the operating room.
• Laparoscopic appendectomy results in a lower wound infection rate compared with an open procedure but has a higher intra-abdominal abscess rate if the appendix is perforated.
• Appendicitis with abscess should not be addressed laparoscopically because the pneumoperitoneum can disrupt the abscess cavity with soilage of the abdomen.
• Dissection of the abscess laparoscopically carries an undue risk of injury to the bowel and mesentery.
• Other relative contraindications to laparoscopic appendectomy include previous abdominal surgery precluding safe trocar placement, uncontrolled coagulopathy, significant portal hypertension, and pregnancy.
• In addition, laparoscopy should be used cautiously in patients infested with HIV or hepatitis C and those who are immunosuppressed.

Perforated or Gangrenous Appendicitis With a Periappendiceal Mass.
When a mass is detected by examination under anesthesia, a transverse incision is made over the most prominent portion of the mass.
• The muscles and aponeuroses are split along their lines of cleavage in gridiron fashion.
• After entering the peritoneal cavity, the wound should be packed immediately to prevent contamination of the abdominal cavity.
• As mentioned earlier, the mass may be made up of omentum and loops of small intestine adherent to the inflamed appendix, and an abscess may not be present.
• If feasible, an appendectomy is then performed; usually it will not be possible to invert the stump, so simple ligation is preferred.
• It is not necessary to place a subfascial drain in a patient with a gangrenous appendix and minimal or no periappendiceal pus.
• If there is a periappendiceal abscess and the tissues are fixed so as to create a dead space, the cavity should be drained with one or more closed suction drains brought out through a separate stab incision.
Before fascial closure, the right iliac fossa and the wound should be liberally irrigated. Muscles and aponeuroses should be closed with interrupted nonabsorbable sutures.
• The skin should be left open, to be closed with adhesive paper tapes on the fifth or sixth postoperative day.
• Parenteral antibiotics should be continued for 5 days after operation or until clinical signs indicate no infection.
• A rectal examination is performed daily to detect the presence of a pelvic abscess.
Perforated Appendicitis With Localized Abscess Formation.
• If, at the time of initial physical examination, a well-localized periappendiceal mass is found and the patient's symptoms are improving, it is acceptable in healthy adults to initiate parenteral antibiotic treatment and to follow the patient expectantly.
• This form of therapy is not appropriate in children, pregnant women, or elderly patients.
• In these groups, an emergency operation is indicated.
• In two thirds of patients, expectant treatment of an appendiceal mass will succeed, and an interval appendectomy can be performed at a later date.
• In one third of patients, symptoms will not subside and an emergency operation should be performed.
o The skin incision for drainage of a periappendiceal abscess is made just medial to the crest of the ilium at the level of the abscess.
o Using a muscle-splitting technique, the lateral edge of the peritoneum is exposed and pushed medially so that the abscess is approached from its lateral aspect.
o Once the abscess is entered, a finger should be used to break up the loculations.
o If the appendix can be freed up without breaking down adhesions, an appendectomy should be performed.
o If an appendectomy is not performed, an interval appendectomy can be done 3 to 6 months after drainage from the abscess has ceased and the wound has completely healed.
o After the wound has been thoroughly irrigated with normal saline, a closed suction drain should be inserted into the abscess cavity and brought out through a separate stab wound in the flank.
o The muscles and aponeuroses are closed with interrupted nonabsorbable sutures, and the skin and subcutaneous tissues are packed open with saline-soaked gauze.
o The drain should be left in place until it is draining less than 50 ml/day and then advanced progressively until removed.
o Systemic antibiotics should be continued for 5 days postoperatively or until signs of sepsis have cleared.
o A daily rectal examination should be done to detect pelvic abscess.
o The patient may be discharged from the hospital when there is no fever 48 hours after the discontinuation of antibiotic therapy.
Perforated Appendicitis With Diffuse Peritonitis.
The major cause of mortality from appendicitis is generalized peritonitis.
o Therefore, immediate exploration is indicated in a patient with a diagnosis of acute appendicitis in whom the physical findings are consistent with diffuse peritonitis.
o If a perforated appendix and diffuse peritonitis are documented at operation, an appendectomy should be performed and the abdomen thoroughly irrigated.
o The wound and postoperative care should be handled as described in a patient with a periappendiceal abscess.
Normal Appendix When Appendicitis Is Suspected.
o If a patient undergoes exploratory laparotomy (especially through a right lower quadrant incision) for suspected acute appendicitis, and a normal appendix is subsequently found, a careful search for another pathologic condition should be made and an appendectomy performed.
o The abdomen should not be closed until the cause of the symptoms has been identified and treated or the surgeon is sure that no lesion requiring treatment is present.
o The normal appendix is removed to obviate diagnostic confusion in the future.
Complications.
Postoperative complications occur in 5% of patients with an unperforated appendix but in more than 30% of patients with a gangrenous or perforated appendix.
o The most frequent complications after appendectomy are
o wound infection,
o intra-abdominal abscess,
o fecal fistula,
o pylephlebitis,
o and intestinal obstruction.
Subcutaneous tissue infection is the most common complication after appendectomy.
o The organisms most frequently cultured are anaerobic Bacteroides species and the aerobes Klebsiella, Enterobacter, and Escherichia coli.
o When early signs of wound infection (undue pain and edema) are present, the skin and subcutaneous tissue should be opened.
o The wound should be packed with saline-soaked gauze and reclosed with Steri-strips in 4 to 5 days.
Pelvic, subphrenic, or other intra-abdominal abscesses occur in up to 20% of patients with a gangrenous or perforated appendicitis.
o They are accompanied by recurrent fever, malaise, and anorexia of insidious onset.
o CT scanning is of great help in making the diagnosis of intra-abdominal abscess.
o When an abscess is diagnosed, it should be drained either operatively or percutaneously.
Some fecal fistulas will close spontaneously, provided that there is no anatomic reason for the fistula remaining open.
o Those that do not close spontaneously obviously require operation.
Pylephlebitis, or portal pyemia, is characterized by jaundice, chills, and high fever.
o It is a serious illness that frequently leads to multiple liver abscesses.
o The infecting organism is usually E. coli.
o This complication has become rare with the routine use of antibiotics in complicated appendicitis.
Although not frequent, true mechanical bowel obstruction may occur as a complication of acute appendicitis. As with any other mechanical small bowel obstruction, operative therapy is indicated.
CHRONIC AND RECURRENT APPENDICITIS
There are occasional patients who have had one or more attacks of what appears to be acute appendicitis.
o Between attacks, these patients are free of symptoms and the physical examination is normal.
o In such patients, if a fecalith is present on abdominal x-ray film, if a BE demonstrates no filling of the appendix, or if repeated examinations during an attack provide evidence of recurrent appendicitis, elective appendectomy should be undertaken.
o To sustain a diagnosis of chronic appendicitis, the resected appendix must demonstrate fibrosis in the appendiceal wall, partial to complete obstruction of the lumen, evidence of old mucosal ulceration and scarring, and infiltration of the wall of the appendix with chronic inflammatory cells.