Microwave tissue coagulator induces renal apoptotic damage to preserved normal renal tissue following partial nephrectomy.
BACKGROUND
We assessed the extent of apoptotic damage induced by the microwave tissue coagulator (MTC) in the preserved normal renal tissue following partial nephrectomy.


METHODS
Eleven patients who underwent nonischemic partial nephrectomy with MTC (group M) were enrolled in this study. The other 11 patients who underwent cold-ischemic partial nephrectomy without the use of MTC were enrolled as controls (group C). There were no significant differences in tumor size or age between the two groups. Renal damage was evaluated by counting apoptotic cells in the normal renal tissue surrounding the tumor tissue. Immunohistochemical staining with single-stranded DNA was carried out to investigate the apoptotic cells.


RESULTS
The number of apoptotic cells in group M ranged from 275 to 508 per 1,000 cells, with a median value of 421. The number in group C ranged from 122 to 466 per 1,000 cells with a median value of 286. The number of apoptotic cells in group M was significantly greater than that in group C (p = 0.006). Blood loss in group C was significantly greater than that in group M (p < 0.0001).


CONCLUSIONS
This study points out that renal damage induced by the use of MTC comprises not only necrosis but also apoptotic change. Although MTC is useful for controlling renal parenchymal bleeding during partial nephrectomy, we must consider that renal apoptotic damage caused by the MTC may spread beyond the coagulated necrosis area.
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan. nanriman@gmail.com.
Masayuki
M
Nanri
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Kazuma
K
Udo
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Maki
M
Kawasaki
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Yuji
Y
Tokuda
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Chisato
C
Fujiyama
Department of Urology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Jiro
J
Uozumi
Department of Pathology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga, 849-8501, Japan.
Shuji
S
Toda
D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000528:radiation effects*; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000528:radiation effects* / Q000601:surgery; D007680:Kidney Neoplasms / Q000601:surgery*; D008872:Microwaves; D008875:Middle Aged; D009392:Nephrectomy / Q000009:adverse effects*