PRIMARY RENAL GRAFT THROMBOSIS

Background. Renal allograft thrombosis is a serious complication of ki dney transplantation that ultimately leads to graft loss. Its associat ion with acute and hyperacute rejection is well documented; however, i n a large proportion of patients the precise cause remains obscure. Th e exact incidence and the associated risk factors for those episodes o f graft thrombosis lacking evidence of rejection have not yet been cle arly established. Methods. All reported episodes of graft thrombosis i n 558 consecutive cadaveric kidney transplants performed in a single c entre were examined to identify those without histopathological eviden ce of rejection, i.e. primary renal graft thrombosis. Univariate and m ultivariate types of analysis were applied to study the possibly relat ed risk factors and any associated morbid event(s) of those episodes. Recipients without reported episodes of primary renal graft thrombosis (n=493) represented the control group for the 34 identified cases. Re sults. The calculated incidence of primary renal graft thrombosis was 6% (1.9% arterial, 3.4% venous and 0.7% both), comprising 45% of early (90 days) and 37% of 1-year graft losses in our centre. The multivari ate analysis identified five independent risk factors for primary rena l graft thrombosis: donor's right kidney P<0.007, past history of veno us thrombosis (renal or extrarenal) P=0.000, and diabetic nephropathy P=0.000 of the recipient, technical surgical problems P=0.000, and rec ipient's haemodynamic status peri and early postoperatively P<0.001. P rimary renal graft thrombosis was related to the presentation with del ayed graft function (DGF) P<0.0005 and was significantly associated wi th extrarenal thromboembolic manifestations P<0.0005. There was no ass ociation between primary renal graft thrombosis and recipient's age, s ex, number ofprevious transplants, type of dialysis, pretransplant tre atment with erythropoietin, antiplatelet agents, or oral anticoagulant s, donor's age, sex, number of graft vessels, warm and cold ischaemia times, site of transplant (R/L iliac fossa) and type of immunosuppress ive agent used for induction whether cyclosporin A (CsA) or OKT3. Conc lusions. Primary renal graft thrombosis is an important cause of graft loss that may be accompanied by thrombosis of extrarenal sites and ef fective, safe prophylactic regimens are needed, especially for those a t high risk.