High intensity focused ultrasound laparoscopic instrument for partial nephrectomy

Abstract

Partial nephrectomy (PN) is the gold standard for small clinically localized renal masses because of equal oncologic outcomes and greater preservation of renal function compared with radical nephrectomy (RN). However, it is a complex operation due to the challenges of cutting into a well-vascularized organ and the need for reconstruction of the remaining kidney following excision. PN is associated with higher blood loss, risk of transfusion, and longer operative time compared to RN. High intensity focused ultrasound (HIFU) affords the ability to ablate tissue and perform hemostasis, thus potentially mitigating some of the challenges associated with PN. The purpose of this paper is to introduce a new HIFU clamp as an adjunctive tool for PN. A HIFU device was created to conform to the shape of a commonly used laparoscopic instrument. Characterization studies were conducted using ex vivo tissue. Histology was performed to evaluate thermal damage. Ex vivo studies indicated that complete ablation planes could be achieved at temperatures sufficient for thermal tissue necrosis. Gross parenchymal changes were observed with clear demarcation between treated and untreated regions. Histological evaluations revealed that there were no viable cells in ablated regions. [This work was funded by NIH (EB013365).]