Value of tomodensitometry with injection and late images for the diagnosis of urinary leaks in kidney transplants

: Between May 1985 and May 1990, 263 renal transplantations were performed in 254 patients, with 4 kidney-pancreas double grafts. 12 urinomas were observed, i.e. 4.56%. In one half of cases, clinical examination alone was able to establish the diagnosis of urinoma, but in the other 6 cases, complementary investigations were required. Post-contrast computed tomography with late images (between 6 and 24 hours after the injection) would appear to be the most useful investigation. Performed in 6 cases, this examination established the diagnosis of urinoma in 5 cases and also suggested the mechanism of the leak, which was always confirmed at operation. The positive diagnosis is based on extravasation of contrast agent which is clearly visible, even in the presence of low concentrations due to impaired renal function. This extravasation occurred early in 3 cases, but was delayed in 2 cases, emphasising the importance of late images. Other investigations appear to be less useful either because of a lack of sensitivity or because of imprecise anatomical information. The severity of urine leaks and the need for rapid treatment justify post-contrast computed tomography with late images in any case of suspected urinoma.