Intraoperative ultrasound: technique and clinical experience in robotic-assisted renal partial nephrectomy for endophytic renal tumors

Surgical removal of completely endophytic renal tumors has presented great technical difficulties for surgeons. In this study, we aim to introduce the role and use of intraoperative ultrasound (IOUS) performed in robotic-assisted renal partial nephrectomy (RAPN) for endophytic renal tumors.

We retrospectively assessed the demographics data and surgical outcomes of 58 consecutive endophytic renal tumor patients who were all attributed 3 points for the 'E' domain of the RENAL nephrometry score or 3 points for the exophytic rate of the PADUA score between October 2016 and September 2018. 38 patients who had undergone RAPN with IOUS were grouped. RAPN was carried out in another 20 patients without IOUS and these 20 patients were also grouped.

Patients in IOUS-guided group had significantly lower estimated blood loss (P < 0.001), shorter warm ischemia time (P = 0.010) and improved MIC (Margin, ischemia, and complications) rate (P = 0.026) and Pentafecta achievement (P = 0.016) compared to non IOUS-guided group. In multivariate logistic regression analysis, RAPN with IOUS was an independent predictor of MIC achievement (odds ratio 3.595; confidence interval 1.023-12.633; P = 0.046). Surface-intermediate-base (SIB) margin score was lower for IOUS-guided group vs non IOUS-guided group (P = 0.029).

RAPN for completely endophytic renal tumors is a feasible procedure in terms of complication rates, oncologic and functional outcomes. A robotic ultrasound probe operated by console surgeon generates a favorable perioperative outcomes and surgical margin rates after RAPN.