Retrograde renal cooling to minimize ischemia

Area of Science:

• Urology
• Surgical Innovation
• Nephrology

Background:

• Partial nephrectomy requires renal hypothermia to mitigate ischemia-reperfusion injury.
• Renal hilar clamping is standard but can be challenging.
• Investigating novel cooling methods is crucial for patient outcomes.

Purpose of the Study:

• To determine the infusion rate for safe and effective renal unit cooling using retrograde irrigation.
• To evaluate cooling efficacy in a porcine model with and without renal hilum clamping.

Main Methods:

• Retrograde irrigation of iced normal saline via a dual-lumen ureteral catheter in a laparoscopic porcine model.
• Monitoring renal cortical, medullary, bowel, and rectal temperatures.
• Testing infusion rates of 300, 600, 1000 cc/hour, and gravity (800 cc/hour) with and without hilar clamping.

Main Results:

• Infusion rates ≥ 600 cc/hour with hilar clamping achieved significant renal hypothermia (cortex and medulla).
• Gravity infusion yielded the lowest renal temperatures.
• Retrograde cooling was minimal without renal hilum clamping.

Conclusions:

• Gravity infusion of iced saline via a dual-lumen catheter with renal hilum clamping effectively induces renal hypothermia in a porcine model.
• Continuous retrograde irrigation may be a viable method for renal hypothermia during robotic-assisted and laparoscopic partial nephrectomy.