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

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 SA syndrome. The SA 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 the left gastric artery (LGA), short gastric vessels, and the gastroepiploic arcade (GEA), with subsequent severe upper gastrointestinal (GI) 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 the SA ligated or interrupted at LT. Among them, 88 had a computed tomography angiography suitable for evaluation of vascular remodeling after LT. The presence of prominent gastric arterial collaterals and the increase in LGA and GEA diameter were evaluated on 2-dimensional axial images and multiplanar reconstructions. Of the 88 patients, 28 (31.8%), 32 (36.4%), and 22 (25.0%) developed gastric collateralization graded as mild, moderate, or severe. Of the patients for whom 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 (odds ratio, 0.84; 95% confidence interval [CI], 0.71-0.98; P = 0.03), whereas a GEA caliper measurement increase was positively correlated with Model for End-Stage Liver Disease score (r2 = 0.12; 95% CI, 0.65-4.15; P = 0.008). Out of 465 patients, 2 (0.43%) had severe episodes of arterial upper GI bleeding, possibly exacerbated by vascular remodeling. In conclusion, vascular remodeling after SA interruption during LT is frequent and can aggravate GI bleeding during follow-up.

Risk factors for arterial hypertension after liver transplantation.

Arterial hypertension represents a common complication of immunosuppressive therapy after liver transplantation (LT). The aim of the study is to evaluate the prevalence and risk factors associated with hypertension after LT. From a cohort of 323 cirrhotic patients who underwent LT from 2008 to 2012, 270 patients were retrospectively evaluated, whereas 53 (16.4%) patients deceased. Hypertension was defined as blood pressure ≥140/90 mm Hg in at least two visits and/or the need for antihypertensive therapy. The prevalence of hypertension was 15% before LT and significantly increased up to 53% after LT (P < .001). Mean follow-up was 43 ± 19 months. In normotensive (NT) subjects at baseline, 35.9% developed sustained hypertension after LT, whereas 15.2% developed transient hypertension within the first month after LT, and then returned NT. The development of sustained hypertension after LT was related to the mammalian target of rapamycin inhibitor treatment (odds ratio [OR], 4.02; 95% confidence interval [CI], 1.26-13.48; P = .02), alcoholic cirrhosis before LT (OR, 3.38; 95% CI, 1.44-8.09; P = .005), and new-onset hepatic steatosis after LT (OR, 2.13; 95% CI, 1.10-4.11; P = .02). Tacrolimus, the etiology and severity of liver disease, and other immunosuppressive regimens were not related to the development of hypertension after LT. In our cohort, the prevalence of arterial hypertension has increased up to 53% after LT, and metabolic comorbidities and immunosuppressive treatment with mammalian target of rapamycin inhibitors are the risk factors for the development of hypertension after LT.