V5-11: Off-Clamp Partial Nephrectomy

Video

Introductions and Objectives
Robot-assisted partial nephrectomy (RAPN) is a viable alternative to open surgery for small renal tumors in selected patients. Off-clamp minimally invasive partial nephrectomy has emerged in an attempt to minimize the loss of renal function by eliminating ischemic renal injury. In the accompanying video (7:04), we demonstrate our technique for off-clamp RAPN in a patient with a complex 3.6cm hilar tumor.

Methods
We performed a retrospective review of our off-clamp RAPN experience between August 2007 and May 2014. Patient demographics, operative information, perioperative outcomes and renal functional outcomes were evaluated. Estimated glomerular filtration rate (eGFR) was calculated with the Chronic Kidney Disease Epidemiology collaboration formula.

Results
152 patients with a mean age of 58.9 (standard deviation [SD]= 12) underwent off-clamp RAPN. Mean BMI was 32.5 (8.1). The mean clinical tumor size was 3 cm (1.6cm) with a mean nephrometry score of 7.1 (2.1). The mean operative time was 171 minutes (61 min), and the mean estimated blood loss was 253 mL (88 mL). Surgical margins were negative in 148 out of 152 tumors with a positive margin occurring in 4 (2.6%) of cases. The mean hospital length of stay was 2 days with 10 (6.6%) postoperative complications. Mean decline in eGFR was 4.4 mL/minute/1.73m2 (5%) and there were no recurrences at mean follow-up of 294 days (range 16 – 1247 days).

Conclusions
The off-clamp RAPN technique, which eliminates WIT, is both safe and effective in the treatment of renal tumors in our experience. The procedure should be performed by an experienced surgeon, and we have found that this technique is applicable to most tumors amenable to minimally invasive partial nephrectomy.

Funding: none