Among adults, “negative” appendectomy, or appendectomy in which the surgeon discovers there is no appendicitis, is associated with a prolonged hospital stay, greater morbidity, and higher costs than is curative nonperforated appendectomy, according to a report in the American Journal of Surgery.

“Many argue that negative appendectomy is justified to decrease the risk of perforated appendicitis, as it has been accepted that an inverse relationship exists between the rates of negative appendectomy and perforated appendicitis. However, with the increasing prevalence of preoperative imaging, the rate of negative appendectomy has been decreasing, whereas the rate of perforated appendicitis has remained largely the same,” said Kyle Mock, MD, of the department of surgery, Harbor-University of California Los Angeles Medical Center, and his associates ( Am J Surg. 2016;212[6]:1076-82 ). The study found that the prevalence of negative appendectomy decreased from 4.5% to 2.8% in California from 2005 to 2011, while the prevalence of perforated appendicitis decreased from 23.1% to 21.7%

In addition, negative appendectomy “was also justified as it is believed to be associated with minimal morbidity and cost. However, the clinical and economic burden associated with negative appendectomy has not been recently studied,” the researchers noted.

To examine this issue, Dr. Mock and his associates analyzed information from a statewide California inpatient database, focusing on 180,958 adult appendectomy admissions during a 6-year period. Compared with nonperforated appendectomy, negative appendectomy required an additional 0.8 days in length of stay, was associated with greater morbidity, and cost approximately $1,063 more per patient. Rates of negative appendectomy also did not correlate with rates of appendiceal perforation, so negative appendectomy cannot be said to prevent what otherwise would have been a ruptured appendix.

“Consequently, negative appendectomy should no longer be thought of as a benign procedure,” the investigators said.

It is important to note that patients who undergo negative appendectomy likely have other disease processes underlying their signs and symptoms, and they likely require longer hospitalization and incur greater morbidity and costs to identify and treat these alternative disorders. In contrast, patients who undergo routine appendectomy usually are discharged home the same day, Dr. Mock and his associates added.

This researchers had no financial relationships or sources of support in the form of grants, equipment, or drugs. Dr. Mock and his associates reported having no relevant conflicts of interest.