Introduction

A piezo actuator-driven pulsed water jet (ADPJ) system is novel surgical device that is not only able to preserve fine blood vessels without thermal coagulation, but also dissect at constant depth and decreases in water volume compared to conventional continuous water jet systems. The aim of this study was to clarify long term renal damages after off-clamp partial nephrectomy (PN) using the ADPJ system in animal experiments.

Methods

Sprague-Dawley rats were divided into 4 groups and subjected to sham operation, off-clamp PN by the ADPJ system, radio knife and soft coagulation. Urine and blood samples were collected, and residual kidney were harvested at 1, 7, 14, 30, and 90 days postoperatively. Renal function was evaluated by serum blood urea nitrogen (BUN). Morphological features and the extent of renal ischemia of resection surfaces were evaluated by Hematoxylin-eosin (HE) staining and by immunostaining using antibodies to 1-methyladenosine (m1A), respectively. Urinary and serum kidney injury molecule-1 (KIM-1) level, which might be elevated in the presence of renal injury, were measured by ELISA. In addition, the expression of KIM-1 RNA extracted from each resection surface were analyzed by quantitative real time reverse transcription polymerase chain reaction.

Results

Serum BUN level of the ADPJ group was significantly lower than soft coagulation group in 1 and 90 days (p<0.01). Although the HE staining of the ADPJ group revealed the crush injury and internal hemorrhage of the resection site in the early phase, the state was gradually recovered with the long-term course after surgery. On the other hands, broader necrosis due to coagulation was shown in radio knife and soft coagulation groups (thermal coagulation groups). The extent of m1A immunostaining were significantly smaller in the ADPJ group than thermal coagulation groups. Urinary KIM-1 level of the ADPJ group was significantly lower than those of soft coagulation group in all evaluation points. Furthermore, serum KIM-1 level of the ADPJ groups was significantly lower than those of soft coagulation groups after the 7 days (p<0.01). The expression of KIM-1 was also significantly lower in the ADPJ group than soft coagulation group in 7 and 90 days (p<0.05).

Conclusions

Renal damages after off-clamp PN using the ADPJ system were significantly less compared with commercialized thermal coagulation devices, contributing to improvement of outcomes after PN.

Funding

none