Portal Vein Thrombosis (PVT) Is Associated with Poor Clinical Outcomes in Acute Pancreatitis: Results from a Propensity-Matched Study on a Nationwide Cohort

Abstract

Introduction: In acute pancreatitis (AP), the inflammatory process may involve the portal vein, this together with action of proteolytic enzymes, weakens the vessel wall and causes stasis of blood flow, which serves as a milieu for the development of portal vein thrombosis (PVT). PVT may adversely influence the clinical course of AP; however there are no inpatient, population-based studies assessing the impact of PVT in AP. We evaluated the prevalence and clinical outcomes of PVT in AP patients in a propensity matched analysis. Methods: The national inpatient sample (1998-2012) was reviewed to identify all patients hospitalized with AP with a concomitant diagnosis of PVT. The primary clinical outcome (mortality, renal failure, respiratory failure and pseudocyst) and secondary resources outcomes (length of stay and total hospital cost) were analyzed using univariate and multivariate comparisons. Propensity score-matched analysis (matched for patient demographics, hospital characteristics, etiology, and AHRQ-Elixhauser comorbidities) was performed to compare the outcomes in patients with and without PVT. Results: PVT is associated with 0.2% (5681/ 3454400) of all AP admissions. There is trend for increased PVT during the study period (47.5/100,000 in 1998 to 347.8/100,000; Cochran Armitage Trend test p < 0.001). Multivariate analysis showed PVT is associated with increased mortality [odds ratio (OR): 1.3, 95% confidence interval (CI) 1.0, 1.7; p=0.023], renal failure (OR 1.5, 95% CI 1.3, 1.6; p < 0.001), respiratory failure (OR: 3.1, 95% CI 2.7, 3.5; p < 0.001), severe AP (OR: 2.5, 95% CI 2.3, 2.8; p < 0.001), prolonged stay (median 5.4 days, p < 0.001) and higher hospital cost (median: $36,509, p < 0.001). Propensity matched analysis confirmed PVT is associated with increased renal failure (OR 1.8; p=0.002), respiratory failure (OR: 2.9; p=0.002), respiratory failure (OR: 2.9; p < 0.001), pseudocyst complication (OR: 4.5; p < 0.001) prolonged stay (median: 5.5 days, p < 0.001) and higher hospital cost (median: $38,123, p < 0.001). Conclusion: PVT is associated with adverse clinical outcomes like organ failure, severe AP, prolonged hospital stay and increased hospital charges which negatively impacts inpatients healthcare utilization. Further studies are needed to determine the optimal strategy for its detection and to reduce disease burden on AP patients.