7.12 Risk Factors Associated with Readmission after Ileal Pouch-Anal Anastomosis: An ACS-NSQIP Analysis

N. P. McKenna1,4, E. B. Habermann3,4, A. E. Glasgow4, K. L. Mathis2, A. L. Lightner2  1Mayo Clinic,Department Of Surgery,Rochester, MN, USA 2Mayo Clinic,Division Of Colon And Rectal Surgery,Rochester, MN, USA 3Mayo Clinic,Department Of Health Science Research,Rochester, MN, USA 4Mayo Clinic,Robert D. And Patricia E. Kern Center For The Science Of Health Care Delivery,Rochester, MN, USA

Introduction: While the increased risk for readmission after ileal pouch-anal anastomosis (IPAA) relative to other colorectal surgery operations is known, reasons and risk factors for readmission remain poorly understood. The purpose of this study was to identify preventable reasons for readmission and to delineate risk factors for readmission in the perioperative period.

Methods: Patients with a diagnosis of chronic ulcerative colitis (CUC) undergoing either total proctocolectomy with IPAA (two-stage) or proctectomy with IPAA (three-stage) were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2012 to 2015.  Reasons for unplanned readmission within 30 days of procedure were reviewed and categorized as infectious, dehydration/electrolyte abnormalities, small bowel obstruction/ileus, venous thromboembolism, ostomy related, pouch related, pain, bleeding, and other/missing. The primary outcome rate measured was readmission within 30 days of discharge as calculated by person-years method. Cox Proportional Hazard models determined independent risk factors for readmission overall and for specific categories.  

Results: 3473 patients met inclusion criteria with an overall readmission rate of 33% per 30 person days. Identified reasons for readmission included infectious complications (32%), dehydration/electrolyte abnormalities (23%), small bowel obstruction/ileus (15%) and venous thromboembolism (VTE) (5%). Multivariable analysis found race/ethnicity of Hispanic white and black/African American (both versus non-Hispanic white, HR: 1.5, p=0.02 and HR: 1.4, p=0.02, respectively) to be independently associated with thirty-day readmission. When looking at specific reasons for readmission, age 57+ (versus age 18-32, HR: 2.3, p<0.01) and hypertension requiring medication (HR: 1.5, p=0.04) were associated with readmission for dehydration/electrolyte abnormalities; two stage IPAA was associated with readmission for VTE (HR 6.5, p=0.01), while obesity (HR 1.5, p<0.01), operative time 330+ minutes (versus <189 minutes, HR: 2.2, p<0.01), and Hispanic white race/ethnicity (versus non-Hispanic white, HR: 2.0, p<0.01) were associated with readmission for infectious complications.

Conclusions: One-third of patients were readmitted after IPAA, with infectious complications and dehydration making up the majority of reasons for readmission. Targets for quality improvement include potentially preventable reasons for readmission such as dehydration and VTE. The development of pathways to prevent dehydration after discharge in high-risk patients and consideration of extended VTE prophylaxis after two-stage IPAA could help reduce the high readmission rate after IPAA.