Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) Classification of Renal Tumours in Patients who are Candidates for Nephron-Sparing Surgery

Abstract

Besides clinical tumour size, other anatomical aspects of the renal tumour are routinely considered when evaluating the feasibility of elective nephron-sparing surgery (NSS). To propose an original, standardised classification of renal tumours suitable for NSS based on their anatomical features and size and to evaluate the ability of this classification to predict the risk of overall complications resulting from the surgery. We enrolled prospectively 164 consecutive patients who underwent NSS for renal tumours at a tertiary academic referral centre from January 2007 to December 2008. Open partial nephrectomy without vessel clamping. All tumours were classified by integrating size with the following anatomical features: anterior or posterior face, longitudinal, and rim tumour location; tumour relationships with renal sinus or urinary collecting system; and percentage of tumour deepening into the kidney. We generated an algorithm evaluating each anatomical parameter and tumour size (the preoperative aspects and dimensions used for an anatomical [PADUA] score) to predict the risk of complications. Overall rates of complication were significantly correlated to all the evaluated anatomical aspects, excluding clinical size and anterior or posterior location of the tumour. By multivariate analysis, PADUA scores were independent predictors of the occurrence of any grade complications (hazard ratio [HR] for score 8-9 vs 6-7: 14.535; HR for score ≥10 vs 6-7: 30.641). Potential limitations were the limited number of patients with T1b tumours included in the study and the lack of laparoscopically treated patients. Further external validation of the PADUA score is needed. The PADUA score is a simple anatomical system that can be used to predict the risk of surgical and medical perioperative complications in patients undergoing open NSS. The use of an appropriate score can help clinicians stratify patients suitable for NSS into subgroups with different complication risks and can help researchers evaluate the real comparability among patients undergoing NSS with different surgical approaches.