Does laparoscopy reduce the incidence of unnecessary appendicectomies?

Abstract

The aim of this study was to evaluate the impact of laparoscopic appendicectomy on the incidence of histologically normal appendices. Between 1987 and 1997, 1,220 patients (average age 23.5 years [17-73]; 841 women [69%]) had appendicectomy due to the presence of at least one of the following three criteria: right iliac fossa guarding, fever >38 degrees C, and leukocytosis >10,000. Patients were divided into two groups: one group of 930 patients were operated on using the classic Mac Burney approach and the other group of 355 patients underwent laparoscopic exploration, with an appendicectomy performed if macroscopic abnormalities were observed (290 cases). In all cases, the appendices were examined blind and classified as normal or pathologic, with the latter divided with respect to the nature and severity of the lesions. In the Mac Burney group, the incidence of histologically normal appendices was 25.1%. In the laparoscopic group, the incidence was only 8.2% (p=0.015). The types of pathologic appendices were identical between the two groups. In 65 cases (18.3%), a macroscopically normal appendix was left in place. In 56 cases the symptoms were due to another identified cause, however, in 10 cases no cause was found. All patients were followed-up for an average of 3 years. One patient (1.8%) had a second operation (an appendicectomy), which revealed minor histologic lesions. The problem is the inability of the operator to differentiate between a healthy and a pathologic appendix on laparoscopy. The risk of false-positives and false-negatives is approximately 10%. Diagnostic difficulties usually occur in the initial phase of the disease with acute mucosal involvement in a morphologically normal appendix. At this stage the outcome cannot be predicted, although appropriate antibiotic treatment can be effective. This study shows that laparoscopy significantly reduces the number of histologically normal appendices as compared to a conventional Mac Burney operation. This can only be achieved by not removing macroscopically normal appendices, a small proportion of which (5-10%) could be cases of early appendicitis with only mucosal involvement. In the absence of other causes of the symptoms, a 3-day course of antibiotics can be tried to treat possible mucosal lesions. This approach reduces costs without having adverse consequences on the outcome.