Study questions surgery for appendicitis

AUSTRALIAN doctors have reacted cautiously to suggestions that a new, conservative approach to treating non-perforating appendicitis with antibiotics be considered rather than surgery, after a US study suggested the treatment of acute appendicitis should be revisited. (1)

The study, published in Archives of Surgery, presented data suggesting that non-perforating appendicitis in children behaves similarly to non-perforating diverticulitis in adults.

The study authors said a growing body of literature suggested that the relationship between non-perforating and perforating appendicitis was not as clear as previously thought. “Given the vastly improved abilities to establish these disease diagnoses and detect complications coupled with more effective antibiotic therapies, the treatment of acute appendicitis should be revisited,” they said.

They said it was assumed, but had never been proved, that appendicitis always perforated unless appendectomy was performed early in its course.

There had been randomised controlled trials comparing antibiotic treatment of appendicitis with surgery, and a non-randomised study demonstrating that acute appendicitis could be safely treated with antibiotics alone, they said.

Professor Danny Cass, professor of paediatric surgery at the University of Sydney and the Children’s Hospital at Westmead, said the study should certainly challenge assumptions and prompt a rethink of current treatment of non-perforating appendicitis.

“My first impression is that we should consider trials using antibiotics in the mild cases, that is, no fever, normal white blood count and only deep tenderness — clearly non-perforated,” he said.

“In this mild group, there need not be admission to hospital but there must be meticulous follow-up and enrolment in a prospective review.”

But Professor Cass said that for children under 10 years with clear signs and symptoms of appendicitis, it could be difficult to be certain that the appendicitis was truly “non-perforated”, so he would be reluctant to change the current approach.

Dr Naeem Samnakay, paediatric surgeon at Princess Margaret Hospital in Perth, said the results were interesting and food for thought but for now, appendectomy remained the gold standard treatment for appendicitis in children.

“To vary management from this would require clear evidence that antibiotic management alone provides a better outcome for children with appendicitis,” he said. “It would also require clear evidence of the natural history and pathogenesis of acute appendicitis and of a difference in pathogenesis, if there is one, between non-perforating and perforating appendicitis. This definitive evidence is currently unavailable.”

Dr Samnakay said his experience was that very young infants and toddlers often present with perforating appendicitis even with short presenting histories. “Our experience also is that children with delayed presentations are more likely to have perforating appendicitis.”

The study authors analysed data from the US National Hospital Discharge Survey to investigate the incidence of admissions for appendicitis in children under 20 years of age and diverticulitis in adults over age 40, between 1979 and 2006.

They found that perforating appendicitis and diverticulitis behaved differently from their non-perforating counterparts.

“These findings seem incompatible with the long-held view that perforating appendicitis is merely the progression of non-perforating disease where surgical intervention was delayed too long,” the authors said.

“If appendicitis represents the same pathophysiologic process as diverticulitis, it may be amenable to antibiotic rather than surgical treatment.”

However, Dr Samnakay said there was much more to acute appendicitis than “perforating” or “non-perforating”. “There is a range of intra-operative appearances of the inflamed appendix, from mild oedema, to suppurative inflammation, to fibrinous inflammation, to gangrenous inflammation.”

An invited critique in Archives of Surgery said more information was required before the approach to non-perforating appendicitis and diverticulitis was altered. (2)

Although the argument put forward by the study authors was well formulated and supported with extensive statistical analysis, the pathogenesis of acute perforating appendicitis was unclear if not originating from its non-perforating predecessor.

“Is it then safe to assume that any two diseases that are equated through cointegration [analysis] are, in fact, the same disease?” the critique said.

The study authors said appendicitis and diverticulitis shared many similarities and some differences. Both were rare where hygiene was poor and diets were high in fibre, there was an increased incidence of both as cleanliness in the Western world had improved, and they were more common in populations with a higher socioeconomic status.

- Cathy Saunders

1. Arch Surg 2011; 146(3): 308-314

2. Arch Surg 2011; 146(3): 315

Posted 28 March 2011