A Combination of the Mayo Adhesive Probability Score and the RENAL Score to Predict Intraoperative Complications in Small Renal Masses

Abstract

<b><i>Introduction:</i></b> To evaluate the potential predictive value of the Mayo Adhesive Probability (MAP) score combined with the RENAL score for intraoperative outcomes in retroperitoneal laparoscopic nephron-sparing surgery (NSS) in an Eastern Asian population. <b><i>Methods:</i></b> An initial of 388 patients undergoing retroperitoneal laparoscopic NSS were identified. MAP and RENAL scores were calculated according to CT and a logistic regression model was adopted as a combination of the RENAL score and the MAP score. <b><i>Results:</i></b> A total of 293 patients were included. The overall intraoperative complication rate was 7.5% (21 cases). The MAP score was found to correlate with operation time (OT; <i>r</i> = 0.169), estimated blood loss (EBL; <i>r</i> = 0.318), and intraoperative complications (<i>r</i> = 0.242). The RENAL score was correlated with warm is­chemia time (<i>r</i> = 0.503), OT (<i>r</i> = 0.334), intraoperative complications (<i>r</i> = 0.178), and EBL (<i>r</i> = 0.218). The MAP score and the RENAL score were reliable predictors of overall intraoperative complications, with areas under the curve (AUC) of 0.728 and 0.759, respectively. After combination of these 2 scores, the AUC of overall intra-operative complications was improved with statistical significance (AUC = 0.847, combination vs. RENAL score: <i>p</i> = 0.044 < 0.05; combination vs. MAP score: <i>p</i> = 0.005 < 0.05). <b><i>Conclusion:</i></b> The MAP score is an important predictor of EBL, OT, and intraoperative complications in retroperitoneal laparoscopic NSS and its combination with the RENAL score showed a superior predictive value compared to a single score in overall intraoperative complications. The MAP score might be considered in preoperative radiologic aspects as regularly as the RENAL score.

Development of a simple nomogram to estimate risk for intraoperative complications before partial nephrectomy based on the Mayo Adhesive Probability score combined with the RENAL nephrometry score

“…Few previous studies have focused on the importance of intraoperative complications, which may be partly due to their rarity. In our study, the incidence rate of intraoperative complications was 7.2%, which is comparable to the rates reported in other studies [ 8 11 12 13 14 ]. The ideal model for prediction of intraoperative complications in PN would include as few components as possible without compromising accuracy.…”

“…Intraoperative complications are important considerations during surgery, since they are associated with adverse outcomes, such as greater blood loss, longer operative time, and even conversion to radical nephrectomy [ 11 14 18 ]. Few previous studies have focused on the importance of intraoperative complications, which may be partly due to their rarity.…”

“…Laparoscopic PN is a technique-demanding surgery, in which local injury can be encountered even in the hands of experienced urologists; however, reports are sparse. During the process of renal dissection and isolation, the toxic sticky fat is identified as a risk factor for injury to local organs or vessels [ 14 19 ]. In general, sticky fat is associated with a high body mass index (BMI), which can be more accurately estimated by the MAP score in retroperitoneal PN.…”

“…Intraoperative complications are rare during surgery in experienced hands, with a reported incidence rate of 5.0% to 13.5% [ 8 11 12 13 14 ]. Typically, conversion to radical surgery and local regional injury are commonly seen.…”

“…However, regardless of their improved predictive accuracy, these new models may be too complex for clinical practice, and some of their components may be less important, which can in turn diminish their actual predictive power [ 2 ]. Both the RNS and the MAP score have been identified as independent risk factors for surgical conversion [ 8 14 16 ]. These two scoring systems focus on different courses of PN, and their combination may theoretically be more comprehensive than the use of either one along for assessing surgical complexity.…”