The risk of developing splanchnic vein thrombosis in acute pancreatitis increases 3 days after symptom onset: A systematic review and meta-analysis

Abstract Background Splanchnic vein thrombosis is a complication of acute pancreatitis (AP) and is likely often underdiagnosed. Objectives We aimed to understand the time course and risk factors of splanchnic vein thrombosis in the early phase of AP. Methods A systematic search was conducted using the PRISMA guidelines (PROSPERO registration CRD42022367578). Inclusion criteria were appropriate imaging techniques in adult AP patients, studies that reported splanchnic vein thrombosis data from the early phase, and reliable information on the timing of imaging in relation to the onset of pancreatitis symptoms or hospital admission. The proportion of patients with thrombosis with 95% confidence intervals (CI) was calculated using random-effects meta-analyses, and multiple subgroup analyses were performed. Results Data from 1951 patients from 14 studies were analyzed. The proportion of patients with splanchnic vein thrombosis within 12 days after symptom onset was 0.13 (CI 0.07?0.23). The occurrence was lowest at 0.06 (CI 0.03?0.1) between 0 and 3 days after symptom onset, and increased fourfold to 0.23 (CI 0.16?0.31) between 3 and 11 days. On hospital admission, the proportion of patients affected was 0.12 (CI 0.02?0.49); it was 0.17 (CI 0.03?0.58) 1?5 days after admission. The prevalence in mild, moderate, and severe AP was 0.15 (CI 0.05?0.36), 0.26 (CI 0.15?0.43), and 0.27 (CI 0.17?0.4), respectively. Alcoholic etiology (0.31, CI 0.13?0.58) and pancreatic necrosis (0.55, CI 0.29?0.78, necrosis above 30%) correlated with increased SVT prevalence. Conclusion The risk of developing splanchnic vein thrombosis is significant in the early stages of AP and may affect up to a quarter of patients. Alcoholic etiology, pancreatic necrosis, and severity may increase the prevalence of splanchnic vein thrombosis.