The Natural History and Traditional Management of Appendicitis Revisited

Data Imply That a Correct Diagnosis is More Important Than an Early Diagnosis

Joseph Tonna; Matthew R. Lewin


AccessMedicine from McGraw-Hill 


Patients presenting with non-specific abdominal pain concerning for acute appendicitis are common in Emergency Departments. It has traditionally been taught that, untreated, appendicitis will progress to perforation with associated morbidity and mortality. This paper reviews the literature regarding differing styles of management of appendicitis and suggests that there is evidence that 1) not all appendicitis progresses to perforation; 2) acute appendicitis may in many instances resolve with conservative management; 3) the rate of perforation may be relatively constant despite operative intervention; and 4) appendectomy, itself, is not necessarily a benign procedure.

Incidence of Appendicitis Correlated with Rate of Surgery

The authors initially cite a study comparing conservative with early aggressive early surgical intervention for appendicitis,[2] which found that patients in the conservative intervention group were less likely (by <36%) to have appendicitis, defined as transmural inflammation at surgery, compared to the patients in the aggressive early surgical intervention arm (P<0.0001). Andersson cites one of his earlier studies in which an analysis of over 56,000 patients correlated the extent of appendectomies with the incidence of non-perforated appendicitis, but independent of the incidence of perforated appendicitis, which they showed to be constant.[3] Both of these studies suggest that as the incidence of looking for appendicitis increases the actual discovery of it, that perforation may not be the end point of all appendicitis and that spontaneous resolution may occur. Andersson cites surgical teaching as far back as 1908 suggesting appendicitis may naturally resolve spontaneously without surgical management. The paper contests that current practice does not consider this a management option in most cases.

Incidence of Perforation

The author cites data[3] to show that while the proportion of detected perforations decreases with the increasing rate of operative intervention, the absolute rate of perforations is constant. This suggests that it is the increased denominator of non-perforated appendicitis detected at operation that accounts for this, rather than prevention of inevitable perforation. Andersson cites the observation that there is a relatively higher proportion of perforated appendicitis in the extremes of age, but suggests—as have others—that this is due to the decreasing total incidence of appendicitis in the very young and very old. He also illustrates that the absolute number of perforations is stable across measured ages.[3,4,5,6,7]

Andersson's discussion includes an alternative explanation to the oft made observation that increased duration of symptoms correlates with increased proportion of perforations. He suggests, and cites data to support, the theory that the increasing proportion of perforations with duration of symptoms is due to selection for these perforated cases, as a not-insignificant number of cases spontaneously resolve, decreasing the denominator (cases of non-perforated appendicitis).

Perforation vs Negative Appendectomy

Andersson's article concludes with a discussion of the risk benefit of perforation vs negative appendectomy, countering earlier data showing a 10-fold increase in mortality with perforation[8,9] with an analysis demonstrating that when controlling for age-related increases in mortality, perforated vs non-perforated appendicitis conferred less than a twofold increased risk.[10]Furthermore, he observes that the surgery for presumed appendicitis, not finding appendicitis, had a significantly higher mortality than appendectomy for appendicitis.[10,11] While he admits the significance of a confounding diagnosis, he concludes with the statement that appendectomy alone is not a harmless operation.


The article summarizes by stating that “In patients with an equivocal diagnosis, where advanced appendicitis is deemed less likely, a correct diagnosis is more important than a rapid diagnosis”[1] and cites multiple sources supporting the observation that active observation of patients with equivocal abdominal pain does not lead to an increase in mortality or perforation, while simultaneously decreasing the negative appendectomy rate.

Relevance to Emergency Medicine

Acute abdominal pain concerning for appendicitis is a common presentation in emergency departments. Traditional teaching has emphasized that delays in diagnosis lead to increased risk of perforation. Perforation is associated with greater morbidity and mortality, especially among extremes of age. For this reason, early diagnosis is touted as standard of care. The standard practice for the diagnosis of appendicitis has evolved from history and physical examination to reliance on computed tomography (CT), ultrasound (US) and, dubiously, laboratory tests such as white cell counts.

If Andersson's suggestion that the incidence of appendicitis correlates with the incidence of surgery, it follows that increased radiographic visualization of the appendix may lead to increased incidence of diagnosis, as many cases of appendicitis that did not warrant surgery in the pre-radiographic era may have gone undiagnosed. If this is true, then the increased visualization of appendicitis has led to an increased rate of appendectomies compared to the pre-CT/pre-US era because of reluctance to consider observation as a management strategy. Furthermore, as this article suggests, the rate of perforated appendicitis may be constant and not preventable by early surgery. Interestingly, mortality rates from acute appendicitis have not notably changed since the 1930s.


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