[An accident related to a seat belt. Lymphocoele and extrinsic stenosis of the ureter in a transplant patient. Reparative surgery (author's transl)].

Trauma to a graft by a seat belt in a young adult, 18 months after transplantation. Drainage shortly after of a voluminous perirenal haematoma, abundant discharge of lymphorrhoea taking two months to resolve. Good recovery of the graft from both a radiological as well as biological standpoint. 4 years after the trauma, leucocytes in the urine associated with impairment of function of the graft. Discovery of a large hydronephrosis related to retro-peritoneal fibrosis. Ureterolysis with resection of the affected part of the ureter followed by anastomosis. Return to normal of renal function with disappearance of the hydronephrosis. Lymphocoele, a rare complication of renal transplantation, is discussed from three viewpoints: aetiopathology, diagnosis and treatment.