In-hospital outcomes of splanchnic vein thrombosis in patients with gastrointestinal malignancies.

853 Background: Splanchnic vein thrombosis (SVT) is an uncommon but important complication of GI malignancies. Evidence on in-hospital outcomes is limited. Methods: We performed a 10-year retrospective study at a tertiary hospital including adults (≥18 years) with active GI malignancy and radiologically confirmed SVT (portal, mesenteric, splenic, hepatic). Exclusions: non-malignant SVT, SVT predating cancer, cirrhosis, portal hypertension, prothrombotic disorders, recent pancreatitis, abscess, pregnancy, hormone therapy without malignancy, or recent trauma/surgery. Outcomes were limited to the index hospitalization. Results: 33 patients met criteria. Median age 70 (IQR 59–77), BMI 26.8 (22.6–34.9). Race: White 87.9%, Black 6.1%, Asian 3.0%, Other 3.0%. All had a smoking history. SVT sites: portal 66.7%, mesenteric 18.2%, splenic 15.2%, hepatic 0%. Cancer sites: pancreas 42.4%, liver 30.3%, colon 9.1%, stomach 6.1%, others 12.1%. Histology: adenocarcinoma 63.6%, hepatocellular carcinoma 30.3%, signet-ring 6.1%. Stage IV in 72.7%. Anticoagulation: LMWH 42.4%, UFH 24.2%, warfarin 3.0%, none 30.3%. At discharge, 42.4% received none (death, hospice, bleeding risk), 33.3% DOACs, 21.2% warfarin, 3.0% LMWH. 1 patient developed bleeding after anticoagulation. In-hospital outcomes: ICU admission 21.2%, mortality 12.1%, median LOS 6 days (2–11). By cancer type: pancreatic had poorest outcomes (ICU 35.7%, mortality 28.6%, LOS 2.5). Liver cancer (n=10) had no ICU or deaths, but longer LOS (11). Colon (n=3) and stomach (n=2) had no ICU/deaths (LOS 2–4.5). Rare cancers: appendix (LOS 1, no ICU/death), bile duct (ICU, survived, LOS 11), esophagus (ICU, survived, LOS 10), rectum (LOS 12, no ICU/death). By SVT type: portal (ICU 18.2%, mortality 9.1%, LOS 6.5), mesenteric (ICU 16.7%, mortality 16.7%, LOS 1.5), splenic (ICU 40.0%, mortality 20.0%, LOS 6). Conclusions: GI malignancy associated SVT carried 12.1% in-hospital mortality and 21.2% ICU admission. Nearly half were discharged without anticoagulation. LMWH was the most common initial therapy, while DOACs and warfarin predominated at discharge. Outcomes were poorest in pancreatic cancer and adenocarcinoma histology; liver cancer patients had prolonged LOS but no deaths. Splenic SVT showed the highest ICU use and mortality, though small numbers limit interpretation. Findings highlight the acute burden of SVT and the need for larger studies to guide long-term management. Group n ICU n (%) Mortality n (%) Median LOS, days (IQR) Overall 33 7 (21.2) 4 (12.1) 6 (2–11) Cancer Pancreas 14 5 (35.7) 4 (28.6) 2.5 (1–7) Liver 10 0 (0.0) 0 (0.0) 11 (6–12) Colon 3 0 (0.0) 0 (0.0) 2 (0–3) Stomach 2 0 (0.0) 0 (0.0) 4.5 (3–6) Appendix 1 0 (0.0) 0 (0.0) 1 (1–1) Bile duct 1 1 (100.0) 0 (0.0) 11 (11–11) Esophagus 1 1 (100.0) 0 (0.0) 10 (10–10) Rectum 1 0 (0.0) 0 (0.0) 12 (12–12) SVT Portal 22 4 (18.2) 2 (9.1) 6.5 (2–11)