Increased incidence of negative appendectomy in childhood obesity

In recent years, there has been worldwide increase in childhood obesity. The diagnosis of acute appendicitis in very obese children can sometimes be difficult and challenging. The purpose of this study was to determine the incidence of histologically normal appendix in very obese and non-obese children undergoing emergency appendectomy for the clinical diagnosis of acute appendicitis.

The hospital records of 1,228 consecutive patients, who underwent appendectomy for acute appendicitis between 2000 and 2008, were analyzed. 207 children (16.9%) were very obese. Very obese was defined as greater than 2 standard deviations above the standardized mean weight for age. Histological data was compared between very obese and non-obese children. Seventy-seven (37%) of 207 very obese and 398 (39%) of 1,021 non-obese children had ultrasound preoperatively.

The incidence of normal appendectomy was significantly higher in very obese children compared to non-obese children (24.6 vs. 9.9%, P < 0.001). The false positive rate of ultrasound was significantly higher in very obese children group compared to non-obese (26 vs. 6%, P < 0.05). The specificity, sensitivity, positive and negative predictive values of ultrasound were significantly lower (P < 0.05) in very obese children group compared to non-obese children.

Suspected appendicitis in childhood obesity is associated with increased incidence of normal appendectomy. Active observation in hospital in very obese children may reduce the rate of normal appendectomy without increasing the incidence of complicated appendicitis.