MONITORING OF RENAL PELVIC PRESSURE IN PATIENTS WITH HYDRONEPHROSIS

A diagnostic method for the determination of obstructions in the pelvo ureteral junction in patients with suspected idiopathic hydronephrosis is described and discussed. Two microtransducer catheters (MTCs) with infusion lumens are inserted under fluoroscopic control, one into the renal pelvis and the other in the perirenal space as a reference. The pressure values obtained are stored on a portable microcomputer syste m, carried by the ambulatory patients. Renal pelvic pressure, intra-ab dominal pressure and differential pressure are calculated and displaye d as time-pressure diagrams on a plotter. The pressures can be measure d for long periods (3-24 h). Furthermore, steady state conditions can be evaluated during pelvic infusion of saline. The results from the pr essure measurements are compared with clinical and radiological evalua tions. Our results show that this method of long-term monitoring of in trapelvic pressure together with intra-abdominal pressure contributes to the evaluation of patients with suspected pelvoureteral obstruction s and complements other methods in the preoperative investigation. How ever, this study reveals difficulties with measurements of intra-abdom inal pressure. Carrying the equipment was not inconvenient for the pat ients.