Contact surface area and its association with outcomes in robotic-assisted partial nephrectomy.

Abstract

Renal tumor scoring systems, such as the contact surface area value, aim to assist in predicting outcomes following robotic-assisted partial nephrectomy. The aim of this study is to identify associations between specific postoperative outcomes and the contact surface area of renal masses. We analyzed 332 consecutive robotic-assisted partial nephrectomies and calculated contact surface area for renal tumors with the contact surface area formula (CSA = 2πrd), where π ≈ 3.14, r = greatest tumor radius (cm), and d = greatest tumor depth (cm). Higher contact surface area was associated with longer warm ischemia time (P < .001), higher estimated blood loss (P < .001), and longer length of hospital stay (LOS) (P < .001). Higher contact surface area was significantly associated with decreased renal function at 1 day, 1 month, and 6 months following robotic-assisted partial nephrectomy. Contact surface area is associated with certain outcomes following robotic-assisted partial nephrectomy and may be a useful predictive tool.