Model for End‐Stage Liver Disease Underestimates Morbidity and Mortality in Patients with Ascites Undergoing Colectomy

BACKGROUND: The Model for End-Stage Liver Disease (MELD) score and ascites correlate with surgical morbidity and mortality. However, the MELD score does not account for ascites. We sought to evaluate whether the MELD score accurately risk stratifies patients with ascites. METHODS: We analyzed the American College of Surgeons National Surgical Quality Improvement Program (2005-2014) to examine the risk-adjusted morbidity and mortality of cirrhotic patients with and without ascites undergoing colectomy for diverticulitis. Patients were stratified by MELD score, and the presence of ascites and outcomes were compared between patients with and without ascites to the reference group of low MELD and no ascites. Multivariable logistic regression was used to control for demographic factors and comorbidities. RESULTS: A total of 16,877 colectomies were analyzed. For each MELD stratum, patients with ascites have increased risk of complications compared to those without ascites (P < 0.05 unless indicated): low MELD ascites OR 1.13, P = 0.69, moderate MELD no ascites OR 1.37, moderate MELD ascites OR 2.06, high MELD no ascites OR 1.93, and high MELD ascites OR 3.54. These trends hold true for mortality: low MELD ascites OR 2.91, P = 0.063, moderate MELD no ascites OR 1.47, moderate MELD ascites OR 5.62, high MELD no ascites OR 3.04, and high MELD ascites OR 9.91. CONCLUSION: Ascites predicts an increased risk for postoperative morbidity and mortality for cirrhotic patients undergoing colectomy for all MELD classifications. These findings suggest that the MELD score significantly underestimates postoperative risk as it does not account for ascites.