AUA 2016: Could perirenal fat be more important than the tumor itself? The MAP score better predicts perioperative morbidity than the RENAL score. - Session Highlights

San Diego, CA USA ( The RENAL Nephrometry score is a validated tool that describes the anatomical complexity of small renal masses that has been shown to predict the complexity of various surgical procedures including partial nephrectomy. Yet, the RENAL nephrometry score only takes into account tumor characteristics such as size, depth, and location, and neglects to account for surrounding environment, such as adherent perirenal fat.

It is well known that the presence of adherent perirenal fat increases the complexity of partial nephrectomy. The Mayo Adhesive Probability (MAP) score is a radiographic score that has previously been shown to aid in the prediction of adherent perirenal fat. Dr. Khene and colleagues sought to compare the predictive ability of MAP compared to the RENAL nephrometry scores for perioperative morbidity of Robot-assisted partial nephrectomy (RAPN).

The authors conducted a retrospective review of 242 patients undergoing RAPN for small renal masses. Using routine preoperative CT images they calculated the MAP and RENAL scores and collected demographic and surgical data. They used univariate to determine variables predictive of blood loss, operative time, and risks for conversion to radical nephrectomy.

They found that both the MAP score and RENAL nephrometry score was associated with a higher rate of conversion to open surgery and the MAP score had higher predictive value (MAP OR= 4.1; 95% CI= 1.7-8.8; p=0.03 and RENAL OR 2.7 0.4-6.3 p=0.37). Both were also associated with risk of conversion to radical nephrectomy (MAP 6.1 vs. RENAL 11.4 2.1- 19.4 p=0.007). Only the MAP score was associated with risks for transfusion (MAP 2.9 1.2-4.1 p= 0.04 vs. RENAL 1.7 0.7- 2.4 p= 0.46) and operative time (beta 0.09, p< 0.001).

Thus the authors conclude the MAP score is a more useful predictive tool for anticipating operative morbidity associated with robotic-assisted partial nephrectomy. It may be easily incorporated into preoperative planning in the assessment of routine preoperative CT imaging. The authors note the limitation of using only univariate and not multivariate analysis to assess the relationship between these two scoring systems and operative outcomes.


Presented By: Zine-Eddine KHENE, MD

Written By: Simone Vernez; Medical Student, Department of Urology, University of California, Irvine at the 2016 AUA Annual Meeting - May 6 - 10, 2016 – San Diego, California, USA