Renal function remains after unilateral total and contralateral partial nephrectomy: an experimental study in pigs...

Area of Science:

• Nephrology
• Surgical Research
• Renal Physiology

Background:

• Kidney adaptation after partial removal is crucial for understanding renal reserve.
• Assessing compensatory mechanisms post-nephrectomy (NE) is vital for surgical outcomes.
• Standardized methods for evaluating renal function in animal models are needed.

Purpose of the Study:

• To evaluate renal function and compensatory adaptation following extensive unilateral nephrectomy (NE) in pigs.
• To determine the safety and functional consequences of removing two-thirds of kidney volume.
• To correlate renography data with biochemical markers of renal function.

Main Methods:

• Twelve pigs underwent left total NE and right partial NE (lower third), removing two-thirds of total kidney volume.
• Renal function was assessed using 99mTc-diethylenetriaminepentaacetic acid (DTPA) renography and serum urea/creatinine levels preoperatively and at 1 and 2 weeks postoperatively.
• DTPA disappearance rate (DDR) was determined via serial blood sampling and gamma imaging ROI analysis, correlating well (r=0.97).

Main Results:

• Postoperative DTPA clearance rates decreased significantly (0.53 to 0.35 ml/s at 2 weeks).
• DTPA disappearance rates also showed a significant decrease (0.99 to 0.63%/min at 2 weeks).
• Despite reduced clearance, DTPA clearance and DDR per kidney area increased significantly, indicating compensatory adaptation. No significant changes in urea or creatinine were observed.

Conclusions:

• Unilateral nephrectomy (NE) in pigs triggers functional adaptation or growth in the contralateral kidney to compensate for renal mass loss.
• Removing up to two-thirds of kidney volume in young pigs can be performed without significant long-term danger to renal function.
• 99mTc-DTPA renography provides a reliable method for assessing compensatory renal function post-NE.