Prospective study for scintigraphic detection of leakage after renal transplantation

Urinary leakage shortly after kidney transplantation can lead to diagnostic difficulties. In a recent article (DeLange et al. 1982) we presented the results of a retrospective study of eight patients with urinary leakage after kidney transplantation. Like others (Haden etal. 1975; Spigos etal. 1977) we concluded that scintigraphy has the potential to be a safe, non-invasive method for early detection of urinary leakage following renal transplantation. In order to evaluate the reliability of the method a prospective study was performed for 1 year. In our hospital routine scintigraphy is performed in all renal transplant recipients within 24 h after transplantation in order to study graft perfusion. We use 99mTc-DTPA, a rapidly excreted kidney-seeking agent. In this study involving 36 patients extra attention was given to signs of urinary leakage on the scintigram, which may be demonstrated by accumulation of radioactivity at abnormal localisations (DeLange et al. 1982). For this study serial scintigraphic studies were made with a 4-s interval to investigate kidney perfusion. At 4, 10 and 15 min static imaging of the kidney and the bladder was performed. An additional scan was made the next day, after the patient had been turned on his side for 30 min to facilitate detection of radioactivity at abnormal localisations. Table I shows the results of the prospective study. In four patients there was scintigraphic evidence of urinary extravasation. In three of these patients urinary leakage was proved by biochemical characterisation of fluid discharged from the wound drain. In one patient the scan showed evidence of leakage, but this could not be confirmed by other methods. However, transient minor leakage could not be excluded. In this case there were no clinical consequences. In the 32 cases in which there was no extravasation demonstrated by scintigraphy, there were no clinical signs indicating urinary leakage. In 10 of these 36 cases there was too little excretion to detect leakage on the direct postoperative scan, but on re-examination shortly afterwards (2-8 days) in 7 cases excretion was sufficient to evaluate