SP768RISK OF ALLOGRAFT THROMBOSIS AND USE OF THROMBOPHILIA SCREEN IN HIGH RISK KIDNEY TRANSPLANT RECIPIENTS (KTRS) -A SINGLE CENTRE EXPERIENCE

Abstract

INTRODUCTION AND AIMS: The reported incidence of vascular thrombosis Thrombophilic disorders are one among several factors causing this major morbidity. Hence there is a need for an effective thrombophilic screening strategy in certain high risk KTRs. AIMS: To define the role of thrombophilia screening in vascular thrombosis after kidney transplantation and its utility in the pre-transplant work up of high risk KTRs METHODS: This is a retrospective observational, cross - sectional analysis of kidney transplant recipients who lost their graft in first year after transplantation between Jan 2005 and Dec 2015. High risk KTRs were defined as those patients who have had a positive family history or background history of thrombosis. Electronic and case notes were used to collect relevant study data on the recipients. RESULTS: Of a total of 2109 Kidney alone transplants over this 11 year period, 120 recipients (5.7%) lost their graft in the first year post-transplant. Of these 120 recipients , 24 (20 %) lost their graft due to vascular thrombosis. Other major causes of graft loss included death with a functioning graft in 26%, unknown etiology in 17% and rejection in 13% of patients. (Fig-1) Of the 24 patients with graft loss due to vascular thrombosis, 12 were male and 12 were female with a , median age of 36 (Range 3-64). 5 were paediatric transplants and 19 were in adults. Eleven were live donor transplants and 13 were deceased donor transplants. 3 recipients had a family history of venous thromboses and 2 recipients had previous history of venous thrombosis (recurrent fistula thrombosis/ DVT). Graft Renal Vein thrombosis, Renal Artery thrombosis and dual thrombosis were identified in 13/24, 6/24 and 4/24 of the group respectively. A Thrombophilia screen was done post operatively in 17 patients, as in the remaining 7 there were clear intraoperative causes identified for thrombosis. 6 of the 17 patients had a positive thrombophilia screen. 22 patients had Transplant Nephrectomy. 7 were commenced on warfarin postoperatively .45%(11) were successfully re-transplanted within a median time interval of 1.5 years. Eight of these 11 re-transplants had intravenous heparin anticoagulation perioperatively. CONCLUSIONS: Allograft vascular thrombosis is responsible for 1-2% of total graft loss in our cohort. The incidence of allograft thrombosis due to pre-existing thrombophilic abnormalities is small. Majority of the patients with vascular thrombosis were found to have negative thrombophillia screening when checked post operatively. During pre -transplant workup, early referral should be made to Haematology for assessing high risk KTRs regarding anticoagulation to prevent allograft thrombosis in the view of equivocal nature of the thrombophilia screening. Further prospective studies are required to determine whether routine clinical screening for thrombophilic factors is justified.