Step-by-step: Intra-arterial renal hypothermia during robot-assisted partial nephrectomy

Renal hypothermia, which can be achieved through several techniques, might allow for longer clamping times in complex robot-assisted partial nephrectomy (RAPN). Intra-arterial cooling (IAC) through arteriotomy was previously found safe and feasible. It may offer several advantages such as prolonged clamping times and working in a bloodless field, allowing for more nephron-sparing surgery in challenging lesions. We provide a step-by-step video elaborating on the surgical technique of RAPN with IAC and present the long-term results of our case series. Ten patients with complex renal masses (deep endophytic, hilar, multiple ipsilateral and very large lesions), where clamping times over 25 min were expected, were treated with RAPN using IAC between March 2020 and March 2023 in 3 referral centers by 2 surgeons. All surgeries were performed using the Da Vinci Xi robot. Three-dimensional (3D) models were created for pre-operative planning and peri‑operative guidance. Median warm, cold and rewarming ischemia times were 4 (IQR 3-7) min, 60 (IQR 33-75) min and 11 (IQR 7-24) min respectively. One case was converted to radical nephrectomy and one case required postoperative coiling due to pseudo-aneurysm formation (Clavien-Dindo 3b). No other intraoperative or postoperative complications occurred. Median pre- and postoperative (3 month and 6 month) GFR values were 90 (IQR 78-90) ml/min, 87 (IQR 71-90) ml/min and 90 (IQR 67-90) ml/min. At a median follow-up of 24 (IQR 13-44) months, the median GFR was stable at 90 (IQR 82-90) ml/min. We present a step-by-step video description of RAPN using IAC. This technique allows for safe prolonged clamping times in complex renal masses, with maintained kidney function and no long-term complications at a median follow-up of 2 years. This technique could be considered by expert robotic surgeons, expanding indications for robotic nephron-sparing surgery.