Appendectomies and the Development of Parkinson's Disease

A recent study from the Cleveland Medical Center has found that undergoing an appendectomy was associated with a 3 times greater risk of developing Parkinson’s disease than those who did not have the surgery.

The study, which was presented at Digestive Disease Week 2019 in San Diego, CA, examined more than 62 million patient records and found that a patient’s relative risk of developing Parkinson’s disease after an appendectomy was 3.19 compared to those who did not undergo the procedure.

"We were interested in the topic because there was no consensus among studies with regard to the association between appendectomy and Parkinson's disease—some showing an increased risk, some a reduced risk, and some with no association," said Gregory Cooper, MD, Division of Gastroenterology at University Hospitals Cleveland Medical Center.

The investigators conducted the study, which is the largest of its kind to date, to examine the relationship between the procedure and the neurological disease, with a retrospective review of more than 62,200,000 patient records from 26 health systems which included 488,190 appendectomy patients.

After an observation wash-out period of 6 months following the procedure, Parkinson's disease was found to have developed in 4,470 of the 488,190 (0.92%) who had received an appendectomy. In the remaining general population, which had not received an appendectomy, there were 177,230 (0.29%) instances of Parkinson's disease. Investigators were unable to determine the time from the procedure until development of Parkinson's consistently based on the available data.

The overall relative risk of developing Parkinson's in patients after appendectomies was calculated as 3.19 (95% CI; 3.10-3.28) compared to those not receiving the procedure. The investigators found similar risk levels across adult age groups, regardless of gender or race.

"This research shows a clear relationship between the appendix, or appendix removal, and Parkinson's disease, but it is only an association," Mohammed Sheriff, MD, lead author of the study, Internal Medicine, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, Ohio said in a released statement.

Co-author Gregory Cooper, MD, Division of Gastroenterology at University Hospitals Cleveland Medical Center, commented on possible implications of the findings for surgical practice. Although emphasizing the place of surgery for patients with appendicitis, Cooper suggested that, if the findings were found to be robust, "one could make a case against an incidental appendectomy in a patient undergoing surgery for another indication."

The study, Parkinson's disease is more prevalent in patients with appendectomies: A national population-based study, was presented May 20 at the DDW 2019 meeting in San Diego, CA.