MP20-06 DIGITAL KIDNEY IN LOCALIZATION OF ENDOPHYTIC RENAL TUMOR DURING PARTIAL NEPHRECTOMY

Abstract

INTRODUCTION AND OBJECTIVES: Endophytic renal tumor was challenging as they hold technical difficulties for tumor localisation because of the lack of external visual cues on the kidney surface. This translates into the key role of intraoperative ultrasonography, which has been traditionally used for partial nephrectomy. Digital kidney, which contains both anatomic and functional data of the kidney, enables visualization of an individual kidney according to the computer renal data by reconstruction. Previously we used digital kidney for planning in laparoscopic partial nephrectomy. Recent publications suggested that the use of augmented reality might improve surgical precision and increase surgeon confidence in operative excision. In this study, we used digital kidney to localize the endophytic tumor during partial nephrectomy. METHODS: 4 patients with completely intraparenchymal renal masses were included. Digital kidney was reconstructed using a three dimentional reconstructive software MIMICS by importing the CT images. After segmentation of the images by the dynamic region growing tool, a mask of both the kidney and the tumor were constructed. During laparoscopy surgery, retroperitoneal approach was used. Initial steps of the procedure included exposure of the kidney and dissection of the renal artery. Transparent digital kidney was fused with a real-time endoscopic image of the operative field, providing a virtual map for the surgeon. The renal artery was used as an internal landmark. After localization of the tumor, partial nephrectomy was performed. RESULTS: Digital kidney localized accurately all the endophytic renal tumors during operation, and coincided with the reality. No ultrosound probe was needed. The mean (range) tumour size was 2.4 (1.8-3.2) cm, operative time was 113 (80-137) min and warm ischaemia time was 21.6 (15-34) min. All cases had negative surgical margins, and no recurrence was evident at a mean follow-up of 12 months. CONCLUSIONS: Digital kidney proved to be functional in accurate localization of the totally endophytic renal tumor during partial nephrectomy. Mounting the pre-operative digital kidney onto the realtime videoendoscopic images will simplify and increase the precision of laparoscopic partial nephrectomy.