Vascular Remodeling of Visceral Arteries Following Interruption of the Splenic Artery During Liver Transplantation

Abstract

Splenic artery (SA) ligation can be performed during liver transplantation (LT) to avoid portal hyperperfusion, which is involved in the pathogenesis of both small‐for‐size and splenic artery syndrome. Splenic artery can also be used as an inflow for arterial reconstruction. Exceptionally, SA interruption or agenesis has been associated with positive remodeling of collateral arteries supplying the spleen via left gastric artery, short gastric vessels and gastroepiploic arcade, with subsequent severe upper gastrointestinal bleeding. To determine incidence, magnitude, predictors and clinical implications of vascular remodeling after SA interruption during LT, we identified 465 patients transplanted in the period 2007‐2017 who had SA ligated or interrupted at LT. Amongst them, 88 had a computed tomography angiography suitable for evaluation of vascular remodeling post‐LT. Presence of prominent gastric arterial collaterals and increase in left gastric artery (LGA) and gastroepiploic arcade (GEA) diameter were evaluated on two‐dimensional axial images and multiplanar reconstructions. Of the 88 patients, 28 (31.8%), 32 (36.4%) and 22 (25%) developed gastric collateralization graded as mild, moderate or severe. Of the patients where comparison with pre‐LT imaging was possible (n = 54), 51 (94.4%) presented a median 37% and 55% increase in LGA and GEA diameter, respectively. Severe gastric collateralization was associated with lower body mass index (OR: 0.84 [0.71‐0.98]; p = 0.03), whereas GEA caliper increase was positively correlated with model for end‐stage liver disease score (R² = 2.4 [0.65‐4.15]; p = 0.008). Two patients out of 465 (0.43%) had severe episodes of arterial upper gastrointestinal (GI) bleeding, possibly exacerbated by vascular remodeling. Conclusion: vascular remodeling after SA interruption during LT is frequent and can aggravate GI bleeding during follow‐up.