Morbidity after negative appendectomy: a single-centre experience on 627 cases

Acute appendicitis is one of the most common causes of abdominal pain in emergency departments worldwide. Despite the improvement in radiological and clinical investigations, negative appendectomy remains a debated topic as well as the optimal strategy for use in cases demonstrating a nonpathological appendix during a procedure for suspected appendicitis. The aim of the present study was thus to analyse clinical outcomes of histologically NA to better elucidate the burden associated with a potentially avoidable procedure.

We retrospectively analysed a prospectively collected database of all patients undergoing appendectomy for suspected appendicitis. Patients who underwent an elective appendectomy or an appendectomy for other causes than suspected appendicitis or even an appendectomy during the course of another procedure were excluded from the analysis.

Data of 627 patients undergoing an emergency procedure for suspected appendectomy were registered. Of the 627 patients, 533 (85%) were found to have acute appendicitis (378 uncomplicated, 155 severe), while the NA rate was 14.9%. A preoperative CT scan was performed in 148 patients (23.6%), an ultrasound evaluation was conducted in 427 patients (68.1%), and 127 patients (20.3%) underwent no imaging prior to surgical intervention. The large majority of procedures was performed laparoscopically (77.7%) and the median procedure duration was 70 min (range 17–270 min). The cumulative conversion rate (both AA and NA) was 5.7%. Leucocytes were significantly lower in cases of NA, while C-reactive protein (CRP) level was found to be increased fourfold in cases of severe versus uncomplicated appendicitis and NA. An increased use of endoloop in appendiceal stump closure was noted in the NA group (88.3% loop vs. 11.7% stapler), while endostapler usage increased in the severe appendicitis group up to 38.1%. Most patients with NA underwent only preoperative ultrasound (71.3%), with just 8.5% of patients in this group having a CT scan before surgery. Ultrasound sensivity was 0.648 and specificity was 0.438. For CT scan, sensivity was 0.949 and specificity was 0.625. LOS in the NA patient group was comparable to that of patients affected by uncomplicated appendicitis, while patients with severe appendicitis experienced a 2-day-longer median recovery. Complications were significantly higher in the severe appendicitis group but comparable in the other two groups. Surgical site infections were the most frequently reported complications.

Young women are particularly at risk for NA. Increasing the use of preoperative CT and incorporating imaging into the overall assessment of a patient seems to be actually the only way to reduce the incidence of NA without increasing the rates of perforation. Considering the relatively high morbidity after an NA procedure, every surgeon must carefully consider the risk–benefit balance prior to performing an appendectomy during diagnostic laparoscopy for suspected acute appendicitis showing a macroscopically noninflamed appendix.