Intrarenal pressures remain low with placement of a dual lumen catheter for retrograde irrigation to induce renal hypothermia

Objective To determine whether placement of a 10 French dual lumen catheter produces a low-pressure collecting system during retrograde irrigation to induce renal hypothermia. Indication for the study is as a potential adjunct for partial nephrectomy. Methods: Ex vivo porcine kidneys underwent harvest, and a ureteral catheter (either single lumen or dual lumen) was placed in the ureter within the renal pelvis. Pressure measurements (n = 1,080) were recorded at 1-s intervals. Irrigant flow rates were initiated at gravity and subsequently increased at 10 cc/min increments to a maximum of 100 cc/min. Results: During retrograde infusion without a dual lumen catheter, every 10 cc/min rate increase resulted in an 8 cm H₂O rise in intrarenal pressure. The maximum flow rate obtained was 20 cc/min before urinary extravasation or intrarenal drainage occurred. Maximum pressure obtained before urinary extravasation or collecting system perforation was 16 cm H₂O. Placement of a dual lumen catheter within the renal pelvis allowed intrarenal pressures to remain less than 5 cm H₂O (when infusion rates<80 cc/min). The maximum flow rate while maintaining pressures <20 cm H₂O was 90 cc/min. Flow rates above 100 cc/ min resulted in urinary extravasation. The maximal flow rate that is safe for collecting systems with a dual lumen catheter is 80 cc/min, and without a dual lumen catheter rates greater than 20 cc/min resulted in collecting system perforations. Conclusion: Using an ex vivo porcine model, application of a 10 French ureteral dual lumen catheter produced adequate retrograde drainage that resulted in low intrarenal pressures at high infusion rates (up to 80 cc/min).