The Impact of Arterial Clamping Technique in Robot-Assisted Partial Nephrectomy on Renal Function and Surgical Outcomes: Six-Year Experience at Siriraj Hospital, Thailand

Abstract

Introduction: Robot-assisted partial nephrectomy (RAPN) with different arterial clamping techniques has increasingly been performed to avoid ischemic injury to nephron. However, postoperative renal function remains controversial. We determine the impact of each renal arterial clamping on surgical and renal outcomes after RAPN. Materials and Methods: Patients who underwent RAPN at Siriraj Hospital from 2010 to 2016 were retrospectively reviewed and stratified into 3 cohorts: main-clamp (MAC), selective-clamp, and off-clamp. Results: Main, selective, and off-clamping were performed in 27, 38, and 12, respectively. Median tumor size and Radius, Exophytic or endophytic, Nearness to collecting system or sinus, Anterior or posterior, and Location relative to polar lines (RENAL) score were 3 cm and 7, respectively. Longer operative time was observed in MAC (p = 0.002) although estimated blood loss, transfusion rate, and complication were comparable. Warm ischemia time was not different between cohorts. However, number of patients with prolonged ischemia time in MAC were greater (p ≤ 0.01). All margins were negative. Median postoperative and latest glomerular filtration rate reduction were 3.8 and 5.3 mL/min/1.73 m², respectively without significant difference between cohorts. On multivariable analysis, hypertension independently associated with reduced renal function preserved (p = 0.03). Median follow-up was 18 months. Conclusions: Our study is the first to report surgical and renal functional outcomes after RAPN in Southeast-Asian population. Based on our experience, clamping techniques does not impact on renal functions and complication rate was low even in small-volume center.