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Updated: Jun 28, 2026
Murine Kidney Transplant Technique
Published on: October 20, 2015
Superheating of the Collecting System during Renal Microwave Ablations; Experimental Study Using an Ex Vivo Perfused
Jorge E Lopera1, Marina Borrego1, Jesus Beltran-Perez1
1Department of Radiology, University of Texas Health Science Center, San Antonio, Texas.
Purpose:
To determine whether the location of the microwave ablation (MWA) probe tip inside a calyx or the renal pelvis can result in excessive heating of the collecting system compared with ablations at the cortex.
Materials And Methods:
Five porcine kidneys were harvested from a local processing plant. The organs were perfused with warmed bovine blood. Ablations were performed using a 60-W MWA system for 5 minutes, with ablations performed by placing the probe tip at the renal cortex, inside a calyx, and inside the renal pelvis. Urine temperatures from the distal renal pelvis were recorded every 60 seconds.
Results:
A total of 33 ablations were performed. The urine temperature increased among all ablation locations. Cortical ablations (n = 14) had a mean maximum temperature rise of 4.6 °C (SD ± 3.0). When ablating with the tip just inside the calyx (n = 12), a substantial rise in the urine temperature existed compared with the cortex group with a mean maximum rise of 31 °C (SD ± 16.7) (P = .016 and P < .001). Ablations with the probe in the pelvis (n = 7) resulted in substantially higher temperatures than those in both cortical and caliceal locations with a mean maximum rise of 70.4 °C (SD ± 9.8) (P < .001 and P < .001).
Conclusions:
In this ex vivo model, urine temperatures in the collecting system substantially increased when the tip of the probe is placed inside a calyx or the pelvis compared with ablations confined to the cortex.
