POSSUM Accurately Predicts Morbidity for Pancreatic Resection

Background: The Physiologic and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) is a predictive scoring system for postoperative morbidity. While numerous studies validate its application to major abdominal surgery, few exclusively consider pancreatic resections, whose unique complications are costly and problematic. We examined whether POSSUM could accurately reflect clinical and economic outcomes in pancreatic resection.

Methods: 326 consecutive pancreatic resections (227 pancreaticoduodenectomies, 87 distal, 7 central, and 5 total pancreatectomies) were performed between October 2001 and January 2007. POSSUM score was prospectively calculated for each case, and patients were stratified to quintiles of morbidity risk: < or = 20%, 20-40%, 40-60%, 60-80%, > or = 80%. Actual clinical and economic outcomes were compared across the groups. Predictive risk assessment was further evaluated independently within each resection type. Logistic regression analysis was performed to identify specific POSSUM parameters predictive of postoperative morbidity.

Results: Observed and Expected morbidity rates were equivalent (53.1% vs 55.5%) with an overall O/E ratio of 0.96. Although no patients presented with POSSUM scores below 20%, a relatively equal distribution was assigned to the remaining risk cohorts. Clinical and economic outcomes progressively worsened with escalations in POSSUM scores. Increasing morbidity risk was associated with significantly longer hospital stays, higher rates of complications, and more blood transfusions, ICU management, and discharge to rehabilitation facilities. This had considerable economic impact, as mean hospital costs rose from $19,951 in the 20-40% risk cohort, to $31,281 in the > or = 80% group. Breakdown by operation type demonstrates that POSSUM definitively predicts morbidity following both proximal and distal resection, but more accurately forecasts the need for ICU management and rehabilitation placement when pancreatoduodenectomy is performed. Multivariate analysis revealed that one-half of POSSUM parameters were significant contributors for postoperative morbidity, with age, preoperative hemoglobin concentration, and intraoperative blood loss demonstrating the strongest correlations.

Conclusion: POSSUM is a valuable perioperative scoring system for evaluating variance in pancreatic surgical methods and outcomes, and can be employed to guide management decisions that impact postoperative recovery.