腎臓のマイクロ波焼灼術における集合管系の過熱： ex vivo灌流腎臓モデルを用いた実験的研究

To determine if the location of the 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.

Five porcine kidneys were harvested from a local processing plant. The organs were perfused with warmed bovine blood. Ablations were performed using a 60W 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.

A total of 33 ablations were performed. The urine temperature increased among all ablation locations. Cortical ablations (n = 14) had a mean ± standard deviation maximum temperature rise of 4.6±3.0 °C. When ablating with the tip just inside the calyx (n = 12) a substantial rise in the urine temperature existed compared to the cortex group with a mean ± standard deviation maximum rise of 31±16.7 °C, p = 0.016 (p < 0.001). Ablations with the probe in the pelvis (n = 7) resulted in substantially higher temperatures compared to both cortical and caliceal locations with a mean ± standard deviation maximum rise of 70.4±9.8 °C, (p < 0.001 and p < 0.001).

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.