External validation of the preoperative anatomical classification for prediction of complications related to nephron-sparing surgery

Purpose: Ficarra et al. (Eur Urol 56:786-793, 2009) published a preoperative anatomical classification (PADUA) to assess the impact of anatomical parameters of renal tumors on complication rate of nephron-sparing surgery (NSS). The objective of this study is to provide a bi-center external validation of this classification using the technique of hilar arterial clamping during open and laparoscopic NSS and to correlate the PADUA score to the ischemia time. Methods: 240 consecutive tumors treated with open and laparoscopic NSS were reclassified according to the PADUA classification. Complications were graded according to the modified Clavien system (Dindo et al. in Ann Surg 240:205-213, 2004). Chi-square tests and multivariate logistic regression models addressed the predictive value of PADUA classification on overall complication rate and grade. Results: Mean patient age was 62.2 ± 13.3 years. Eastern Cooperative Oncology Group performance was 0 in 76%, 1 in 22% and 2 in 2%.61 (25%) were treated laparoscopically. The median PADUA score was 7.5 (range 6-13). Mean surgery and ischemia time was 189 ± 95 and 24 ± 22 min, respectively. Overall complication rate was 23% (n = 54). On univariate analysis, the PADUA score correlated with complication rate (p < 0.001) of open and laparoscopic NSS. On multivariate, only the PADUA score correlated with complication rate (p = 0.0056). Ischemic time correlated with the PADUA score and was significantly higher in PADUA score ≥ 10 (p = 0.034). Conclusions: The PADUA score is a reliable tool to preoperatively predict the risk of complications. In addition, it might be beneficial for a more objective patient selection for laparoscopic surgery and teaching NSS.