Differences in short-term outcomes among patients undergoing IPAA with or without preoperative radiation: a National Surgical Quality Improvement Program analysis.

Abstract

Single-institution studies demonstrate a correlation between preoperative pelvic radiation and poor long-term pouch function after IPAA. The rarity of the radiated pelvis before these procedures limits the ability to draw conclusions on the effects of preoperative radiation on short-term outcomes, which may contribute to long-term pouch dysfunction. The purpose of this work was to better understand the impact of pelvic radiation on short-term outcomes in patients undergoing IPAA. We conducted a retrospective review of the American College of Surgeons National Surgical Quality Improvement Program database (2005-2011). The study was conducted at all participating NSQIP institutions. The cohort was composed of patients undergoing nonemergent IPAA procedures. Proportions of patients experiencing postoperative complications within 30 days were compared by Fisher exact and Wilcoxon rank-sum tests based on whether they received preoperative radiation. Multivariate logistic regression models controlled for the effects of multiple risk factors. Included were 3172 patients receiving IPAA; 162 received pelvic radiation. The postoperative complication rate was not significantly different in patients receiving pelvic radiation versus not receiving pelvic radiation (p = 0.06). In a subset of patients with cancer diagnoses (n = 598), 157 received pelvic radiation; complication rates were not significantly different (p = 0.16). Patients receiving pelvic radiation had significantly lower rates of sepsis in both the overall and cancer diagnosis groups (p = 0.005 and p = 0.047), a finding which persisted after controlling for the effects of multiple risk factors (multivariate p values = 0.030 and 0.047). This was a retrospective database design with short-term follow-up. Patients who received radiation before IPAA had no difference in overall 30-day complication rates but had significantly lower rates of sepsis when compared with patients not receiving pelvic radiation. The perceived inferior long-term pouch function in patients undergoing preoperative pelvic radiation does not appear to be attributable to increases in 30-day complications.