Short- and long-term outcomes of acute diverticulitis in patients with transplanted kidneys

Aim: The safety of nonoperative treatment for patients with transplanted kidneys who develop acute diverticulitis is unclear. Our primary aim was to examine the long-term sequelae of nonoperative management in this group.

Method: We performed a population-based retrospective cohort study using linked administrative databases housed at ICES in Ontario, Canada. We included adult (≥18 years) patients admitted with acute diverticulitis between April 2002 and December 2019. Patients with a functioning kidney transplant were compared with those without a transplant. The primary outcome was failure of conservative management (operation, drainage procedure or death due to acute diverticulitis) beyond 30 days. The cumulative incidence function and a Fine-Grey subdistribution hazard model were used to evaluate this outcome accounting for competing risks.

Results: We examined 165 patients with transplanted kidneys and 74 095 without. Patients with transplanted kidneys were managed conservatively 81% of the time at the index event versus 86% in nontransplant patients. Short-term outcomes were comparable, but cumulative failure of conservative management at 5 years occurred in 5.6% (95% CI 2.3%-11.1%) of patients with transplanted kidneys versus 2.1% (95% CI 2.0%-2.3%) in those without. Readmission for acute diverticulitis was also higher in transplanted patients at 5 years at 16.7% (95% CI 10.1%-24.7%) versus 11.6% (95% CI 11.3%-11.9%). Adjusted analyses showed increased failure of conservative management [subdistribution hazard ratio (sHR) 3.24, 95% CI 1.69-6.22] and readmissions (sHR 1.55, 95% CI 1.02-2.36) for patients with transplanted kidneys.

Conclusion: Most patients with transplanted kidneys are managed conservatively for acute diverticulitis. Although long-term readmission and failure of conservative management is higher for this group than the nontransplant population, serious outcomes are infrequent, substantiating the safety of this approach.