Evaluation of modified RENAL nephrometry score in the prediction of perioperative outcomes of open partial nephrectomy.

Introduction: RENAL nephrometry score (RNS) is a standardized system to grade the complexity of renal masses, but it does not correlate well with the perioperative outcomes of open partial nephrectomy (OPN). To overcome these shortcomings, a modified RNS (MRNS) has been proposed. In this study, we evaluated the MRNS and its role in predicting the perioperative outcomes of OPN.

Methods: This was a prospective observational study performed at a tertiary care hospital to evaluate the efficacy of MRNS in predicting the perioperative outcomes of OPN. Sixty-four cases were included in the study. Demographic parameters, tumor characteristics, and perioperative outcomes were analyzed. Correlation with the post-operative outcomes and the strengths of MRNS were compared with various other nephrometry scores.

Results: The mean age of the patients was 52.89 years, 60.9% were male and 53.1% had a right-sided mass. The comorbidities, body mass index, and performance scores were evenly distributed across the complexity groups (P > 0.05). The mean tumor size was 4.13 cm and the mean MRNS and RNS were 9.45 and 6.1, respectively. 60.9% of the cases had no complications. Major complications (Clavien-Dindo grade [CDG] 3+) were noted in five cases (7.8%). The trifecta of neargin, ischemia, and complications (MICs) score was achieved in 85.9% and was achieved in 71.9% of the cases. MRNS was found to be an independent predictor of the trifecta outcomes (P = 0.04). Receiver-operating characteristic curve of MRNS analyzing the major complications as per the CDG showed an area under the curve of. 804, indicating good prediction of complications by the MRNS.

Conclusions: MRNS improves the predicting power of RNS by attributing enhanced scores to key elements and by adding new elements. Also, MRNS has good ability to predict the achievement of the trifecta and MIC.