Impact of Inner Layer Renorrhaphy Suture on Renal Artery Pseudoaneurysm Formation Following Robotic-assisted Partial Nephrectomy.

OBJECTIVE: To report the impact of resection base inner layer renorrhaphy suture type on renal artery pseudoaneurysm (RAP) rate following robotic-assisted partial nephrectomy (RAPN). METHODS: Five hundred and sixty-three consecutive RAPNs performed by a single surgeon were retrospectively reviewed. Patients were classified into 3 categories: (1) No base suture, (2) monofilament barbed suture (2-0 V-Loc 180 absorbable suture, Medtronic, Minneapolis, MN), (3) polyglactin 910 (2-0 Vicryl coated suture, Ethicon Inc, Cincinnati, OH). In a secondary analysis, we evaluated suturing (Vicryl and V-Loc) vs no base suture. All patients had outer cortical renorrhaphy performed with 0-Vicryl suture utilizing the standard sliding clip technique. RESULTS: One hundred ten patients (19.5%) had V-Loc suturing, 255 patients (45.3%) had Vicryl suturing, and 198 patients (35.2%) had no base suture. Patients had a median age of 62.8years (interquartile range: 53.5-69.7) and median RENAL score was 8 (6-9). Median mass size from preoperative imaging was 3.0 cm (2.5-4.0) for V-Loc, 3.3 cm (2.5-4.2) for Vicryl, and 2.0 cm (1.8-3.0) for no base suture (P < .001). Overall, 21 patients (3.7%) developed a symptomatic postoperative RAP. The rate of RAP was 3.6% (4/110) for V-Loc, 3.9% (10/255) for 2-0 Vicryl, and 3.5% (7/198) for no base suture (P = 1.00). Similarly, the rate of RAP was 3.5% (7/198) for no base suture and 3.8% (14/365) for base suture (P = 1.00). CONCLUSION: Utilization of base suture and type of base suture used during RAPN was not predictive of postoperative RAP development.

Validation of new baseline renal function predictive model in robotic-assisted partial nephrectomy cohort.

OBJECTIVE: To validate a new baseline estimated glomerular filtration rate (NB-GFR) formula in a cohort of robotic-assisted partial nephrectomies (RAPN). METHODS: NB-GFR = 35 + preoperative GFR (× 0.65) - 18 (if radical nephrectomy) - age (× 0.25) + 3 (if tumor size >7 cm) - 2 (if diabetes). NB-GFR was calculated in 464 consecutive RAPN from a single surgeon cohort. 143 patients were excluded secondary to insufficient eGFR follow up. We analyzed NB-GFR accuracy utilizing the last observed eGFR 3-12 months post RAPN. Categorical variables were summarized with the frequency and percentage of patients. Numerical variables were summarized with the median, 25th percentile, and 75th percentile. RESULTS: The mean difference between observed and predicted NB-GFR was 4.6 ml/min/1.73m2 (95% CI -6.9 to 16.1 ml/min/1.73m2 ). There was a pattern of higher observed NB-GFRs being underestimated by the NB-GFR equation while lower observed NB-GFRs were overestimated by the NB-GFR equation. The NB-GFR formula had a high level of accuracy with 98.8% of predicted NB-GFRs falling within 30% of the observed NB-GFR (95% CI 86.8% to 99.5%). The median and interquartile range of the difference between observed and predicted NB-GFR was 3.9 ml/min/1.73m2 (IQR 0.7 to 8.2 ml/min/1.73m2 ). The sensitivity, specificity, positive predictive value, and negative predictive value for the ability of predicted NB-GFR to identify those with an observed NB-GFR <60 ml/min/1.73m2 after RAPN was 98%, 92%, 88%, and 99%, respectively. CONCLUSION: The NB-GFR equation developed with partial and radical nephrectomy cohorts is accurate in predicting post-operative eGFR 3-12 months following RAPN.