The piezo actuator-driven pulsed water jet system for minimizing renal damage after off-clamp laparoscopic partial nephrectomy

In the setting of partial nephrectomy (PN) for renal cell carcinoma, postoperative renal dysfunction might be caused by surgical procedure. The aim of this study was to clarify the technical safety and renal damage after off-clamp laparoscopic PN (LPN) with a piezo actuator-driven pulsed water jet (ADPJ) system. Eight swine underwent off-clamp LPN with this surgical device, while off-clamp open PN was also performed with radio knife or soft coagulation. The length of the removed kidney was 40 mm, and the renal parenchyma was dissected until the renal calyx became clearly visible. The degree of renal degeneration from the resection surface was compared by Hematoxylin-Eosin staining and immunostaining for 1-methyladenosine, a sensitive marker for the ischemic tissue damage. The mRNA levels of neutrophil gelatinase-associated lipocalin (Ngal), a biomarker for acute kidney injury, were measured by quantitative real-time PCR. Off-clamp LPN with ADPJ system was successfully performed while preserving fine blood vessels and the renal calix with little bleeding. In contrast to other devices, the resection surface obtained with the ADPJ system showed only marginal degree of ischemic changes. Indeed, the expression level of Ngal mRNA was lower in the resection surface obtained with the ADPJ system than that with soft coagulation (p = 0.02). Furthermore, using the excised specimens of renal cell carcinoma, we measured the breaking strength at each site of the human kidney, suggesting the applicability of this ADPJ to clinical trials. In conclusion, off-clamp LPN with the ADPJ system could be safely performed with attenuated renal damage.