P109 Outcomes of endovascular interventions for clinically significant transplant hepatic artery stenosis

<h3>Introduction</h3> Hepatic artery stenosis (HAS) has an incidence of 4 - 10% post orthotopic liver transplantations (OLTs). Up to 65% will progress to hepatic artery thrombosis (HAT) within 6 months, if left untreated. HAT can lead to fatal outcomes including biliary stricture, graft lost, and death. This study evaluated the outcomes of endovascular interventions for clinically significant HAS post liver transplantation. <h3>Methods</h3> A retrospective study of clinically significant transplant HAS patients who received endovascular intervention between January 2013 to December 2023 was conducted at a liver transplant centre. Clinically significant HAS was defined by the presence of either biochemical abnormalities and/or biliary complications in HAS. The degree of stenosis and vessels morphology pre interventions were evaluated using CT and conventional angiography. The clinical success is defined as post intervention residual stenosis &lt;30%. The primary patency rate was defined as the time from the initial intervention to any subsequent intervention procedure to maintain hepatic artery patency, first occurrence of HAT, or reaching a censored event. The main therapeutic outcomes were evaluated in terms of artery patency, re-intervention, re-transplant. <h3>Results</h3> A total of 22 patients were included. 77.3% (17/22) following their first OLT and 22.7% (5/22) their second. 27.3% (6/22) had aortic conduit. All patients had deranged liver function at the time of detection of HAS, and 36.4% (8/22) developed ischemic cholangiopathy. The most common HAS site was the anastomosis 77.3% (17/22). The mean time to initial endovascular intervention after transplantation was 8.27 ± 10.88 months. A stenosis of &gt; 70% was present in 59.1% (13/22), the remaining 9 cases demonstrated 50 - 70% stenosis. Vessel tortuosity was present in 77.3% (17/22) and a kink was present in 31.8% (7/22). Technical success was 90.9% (20/22). Clinic success was achieved in 95% (19/20) including 11 patients with no residual stenosis. The primary artery patency rates at 1 and 2 year were 90.9% (20/22) and 68.8% (11/16), respectively. Longer patency rates cannot be reliably differentiated due to small cohort and patients’ death. The 1,3,5 year overall survival rates were 100%, 88.9%, and 71.4%, respectively. No major complications were observed. Re-intervention in 15% (3/20 patients (stent=2, 1=angioplasty), re-transplantation in 10% (2/20). <h3>Conclusions</h3> Angioplasty is an effective and safe endovascular intervention for clinically significant HAS to prevent HAT and graft loss. Stenting could be considered in recurrences.