Acute Appendicitis in Patients with End-Stage Renal Disease

Background: Acute appendicitis in patients with end-stage renal disease (ESRD) poses a diagnostic challenge. Delayed surgery can contribute to higher morbidity and mortality rates. However, few studies have evaluated this disease among ESRD patients. Our study focused on the lack of data on the incidence and risk factors of acute appendicitis among ESRD patients and compared the outcomes in patients who underwent different dialysis modalities. Methods: This national survey was conducted between 1997 and 2005 and included ESRD patients identified from the Taiwan National Health Insurance database. The incidence rate of acute appendicitis in ESRD patients was compared with that in randomly selected age-, sex-, and Charlson comorbidity score-matched non-dialysis controls. A Cox regression hazard model was used to identify risk factors. Results: Among 59,781 incident ESRD patients, matched one-to-one with controls, there were 328 events of acute appendicitis. The incidence rate of 16.9 per 10,000 person-years in the ESRD cohort was higher than that in the control cohort (p = 0.003). The independent risk factors were atrial fibrillation (hazard ratio [HR], 2.08), severe liver disease (HR, 1.74), diabetes mellitus (HR, 1.58), and hemodialysis (HR, 1.74). Compared with the control cohort, subsequent perforation and mortality rates of acute appendicitis were also higher in the ESRD cohorts. There was no effect of dialysis modality on the patient outcomes. Conclusions: ESRD patients had a higher risk for acute appendicitis and poorer outcomes than non-dialysis populations. A careful examination of ESRD patients presenting with atypical abdominal pain to avoid misdiagnosis is extremely important to prevent delayed surgery.