Surgeons have been successfully treating appendicitis, an ancient disease, for more than 100 years.^[1] Have there been recent changes to the traditional management of this common disease since McBurney's careful description near the end of the 19th century? The opening general session of the 2008 American College of Surgeons annual meeting in San Francisco took a careful look at this familiar disease.

Benjamin W. Dart, MD, Medical Director, Skills and Simulation Lab, at the University of Tennessee, Chattanooga, opened the session with a discussion of appropriate antibiotic use and whether obtaining a culture at the time of surgery is useful. It is now known that 10-12 mixed bacteria are involved, rather than a single organism, and many of these bacteria are anaerobes, which resist rapid identification, making a culture of little value. In addition, morbidity remains unchanged even if antibiotics are switched in response to culture results.

Dr. Dart cited a meta-analysis of 45 studies that clearly favored the routine use of antibiotics for patients with acute appendicitis, given the gratifying drop in mortality from appendicitis with the widespread use of these agents.^[2] The effect of timing (pre/post/intraoperative) appears to be equivalent and single doses have the same effect as multiple doses. Dr. Dart commented that a Danish study showed the use of antibiotics reduces wound infection rate from 8.5% to 2.5%.

Dr. Dart concluded that prophylactic antibiotics for less than 24 hours was appropriate for nonperforated appendicitis, with a longer course (2-7 days) recommended for perforated appendicitis. Rarely should antibiotic therapy exceed 5 days and monotherapy may be just as effective as use of multiple agents.

John R. Potts III, MD, Professor of Surgery, Assistant Dean for Graduate Medical Education, Residency Program Director, and Vice-Chairman for Education at The University of Texas Medical School at Houston, had the most challenging topic: "Acute appendicitis -- who needs an operation?" Is nonsurgery a viable choice for patients with appendicitis, or is it crazy, unacceptable, and potentially dangerous? If not, which patients might be suitable for observation? If we do decide to observe such patients, will they eventually need surgery?

Dr. Potts opened by presenting data based on sailors in the US Navy in whom appendicitis developed while on submarine duty. Experience during World War II and more recent data from nuclear submarines shows that nearly 85% to 90% of sailors with suspected appendicitis recovered without surgery. More convincing data came from a randomized trial conducted in 1995, which studied 40 patients with suspected appendicitis; 20 received traditional surgical treatment and 20 received antibiotics intravenously for 2 days followed by oral treatment. Only a single patient who was treated conservatively needed immediate surgery for progressive disease; 7 other patients in that group required surgery within a year for a recurrent attack of appendicitis.^[3] This small trial suggests that progressive disease does not develop in most patients with suspected appendicitis who are treated with antibiotics alone.

Styrud conducted a similar but much larger study involving 252 Swedish male patients with appendicitis initially treated with conventional surgery or antibiotics. Of the 128 patients who did not undergo surgery, 113 improved (88%); only 17 eventually required surgery with an average interval of 4 months.^[4]

To the limited evidence from these clinical trials we can add the combined anecdotal experience of thousands of general surgeons. Before the computed tomography (CT) era, the accuracy rate for diagnosing appendicitis was around 80%. It is reasonable to assume that misdiagnosis was bidirectional, implying that surgeons must have failed to diagnose the disease in some patients, many of whom never had another attack.

Dr. Potts concluded his talk by listing the types of patients in whom appendectomy might be avoided:

• Patients with an appendiceal abscess, who would be better treated with percutaneous drainage;
• Patients who have had a recent myocardial infarct;
• Patients with severe lung disease;
• Women in the first trimester of pregnancy; and
• Persons in a remote environment such as Antarctica or on a mission to Mars.

What is the best way to manage complicated appendicitis? To answer this, Richard C. Thirlby, MD, of the Virginia Mason Medical Center, Seattle, Washington, reviewed the role of CT. CT scans are obtained in about 90% of all suspected appendicitis patients and their accuracy as a diagnostic tool within a community setting is about 90%. Fifteen percent to 20% of appendicitis patients will have complicated disease -- either an abscess or phlegmon, with an adequate assessment, these patients can be diagnosed preoperatively. Only about 20% of these patients will require percutaneous drainage to relieve their symptoms. Fortunately after percutaneous drainage, a fecal fistula rarely ensues, probably because the lumen of the appendix is obstructed at the cecal junction. Furthermore, the failure rate following a non-surgical approach to complicated appendicitis is about 7% -- much lower than the failure rate following immediate surgery. When compared to immediate surgery, there is a strong advantage for postponing surgery.^[2]

Only about 2% of patients will have either an underlying malignancy or a serious benign disease such as regional enteritis, but because of this small risk, patients with appendicitis chosen for a conservative approach should have a follow-up examination (CT or colonoscopy) after the acute process subsides.

Is it necessary to perform interval appendectomy in the nonoperated group of patients with complicated appendicitis? Current evidence suggests that surgery may never be necessary because further problems developed in only about 7% of patients, perhaps because formation of an abscess obliterates the appendix.^[5]

Joseph B. Cofer, MD, Professor and Program Director, Surgery Residency, University of Tennessee at Chattanooga, concluded the panel discussion by discussing the management of unexpected findings at the time of surgery. Most surgeons, if faced with a normal appendix at the time of surgery will proceed with the planned operation. Dr. Cofer agreed with this strategy except when the underlying disease involves the base of the appendix -- for example, from regional enteritis.

With an overall frequency in the general population of about 6% to 7%, appendicitis is one of our most common digestive tract surgical diseases. Appendicitis develops in most within the first few decades of life, although it is uncommon in patients younger than 5 years of age. After age 50, the risk of appendicitis is 1/35 for males and 1/50 for females; after age 70, the overall risk is only about 1/100. The surgeon needs to be cautious, then, in diagnosing appendicitis in the very young or in older patients and in such groups, a correctly interpreted CT scan or an ultrasound is important.

Questions

During the question period, surgeons asked detailed questions pertaining to diagnosis and management:

• Suppose you are called at midnight about a patient with clinical and CT-confirmed appendicitis. He doesn't seem too sick, so you decide to administer antibiotics, postponing surgery to the morning, rather than bringing in the entire operating team for a middle-of-the-night procedure. But next morning, the patient seems fine. Should you operate? The majority of panelists felt it was reasonable to observe the patient for 24 hours and if he/she remained free of symptoms, then discharge.
• Does a young male with typical clinical and laboratory findings of appendicitis need a CT scan? The panel said "No." However, Dr. Thirlby recounted recent experience reported from Washington, where over 90% of suspected appendicitis patients have already had a CT scan prior to being seen by a surgeon. Dr. Potts pointed out that nearly every emergency department patient receives a CT scan, often for questionable indications. He described a recent patient with a painful anal fissure who underwent CT, which had minimal diagnostic or therapeutic value.
• What about use of magnetic resonance imaging for pregnant women with appendicitis? This is a good idea, because an magnetic resonance image avoids the radiation of a CT scan, although an ultrasound is cheaper and more easily available.
• How accurate is ultrasound for diagnosing appendicitis? Ultrasound is not as accurate as CT, but it's excellent for children, in whom it is important to minimize radiation.
• Is it useful to instill a rectal contrast agent prior to obtaining a CT scan? The panel agreed this was a good strategy, but a survey of the audience found it is rarely used.
• Has the use of CT scans increased the accuracy of diagnosis of appendicitis? The panel pointed out that there is conflicting evidence and the existing evidence is most often based on time trends rather than randomized trials.
• If a surgeon decides to postpone surgery in a patient with acute appendicitis, what is the appropriate interval? Four to 6 weeks seems about right.

Summary

This session reminds us that there have been recent dramatic changes in the management of appendicitis -- one of our most common surgical emergencies.

• Antibiotics are clearly effective in reducing the morbidity and mortality from appendicitis, and monotherapy may be just as effective as multiple drugs;
• Cultures are not helpful;
• Not every patient with appendicitis needs an operation. In fact, in some patients a non-surgical strategy is preferred. This group includes patients with a recent heart attack or other serious medical condition, and patients in the first trimester of pregnancy;
• For complicated appendicitis (abscess or phlegmon) recent reports favor a non-operative approach; and
• After beginning the procedure, if the surgeon finds a normal appendix but another disease is present, appendectomy should nearly always be performed.

References