PITFALLS IN THE DETECTION OF URINARY EXTRAVASATION FOLLOWING MAJOR URINARY-TRACT RECONSTRUCTIVE SURGERY

Urinary extravasation may complicate the postoperative course of urina ry tract reconstructive surgery. Early diagnosis of extravasation is c ritical in the postoperative management. In this study we assessed pro spectively the various diagnostic techniques employed in the detection and documentation of urinary extravasation in 76 consecutive patients who underwent major urinary tract reconstructive surgery. Assessment included measurements of the volume of the fluid obtained from the dra ins, analysis of serum to fluid creatinine ratio, detection of intrave nously injected indigo dye and traditional radiographic evaluation. Ur inary extravasation was detected in 7 patients (9.2%). Increased creat inine ratio had the highest diagnostic accuracy: 97.3%, sensitivity 71 .4% and specificity 100%. Various radiological investigations had accu racy of 96%, sensitivity 85.7% and specificity 97.1%. The combined use of these methods detected all cases of urinary extravasation with sen sitivity, specificity and total accuracy of 100%. Fluctuations in the volume of fluid in the drains and intravenous injection of indigo dye had lower accuracy, sensitivity and specificity and added very little to the workup. We conclude that radiological investigations and creati nine ratio analysis are highly accurate complementary methods for the early detection and monitoring of urinary extravasation following reco nstructive urinary tract surgery.