Modified C index: Novel predictor of postoperative renal functional loss of laparoscopic partial nephrectomy

Abstract

Introduction: We aimed to develop a scoring system to quantify the distance between the renal hilum and renal tumour, termed the modified C index (m-CI), and to predict renal functional loss (RFL) following laparoscopic partial nephrectomy (LPN). Methods: The m-CI was measured by using computed tomography in 113 patients who underwent LPN between May 2003 and June 2014. The RFL following LPN was calculated by examining the estimated glomerular filtration rate (eGFR) and radioisotope renography one year postoperatively. The Pythagorean theorem was used to calculate the distance from the tumour centre to the renal hilum. The distance was divided by the tumour radius to obtain the m-CI. The correlation between the m-CI and the postoperative RFL were evaluated using Pearson's coefficient values. Multivariate logistic regression models were used to assess the potential predictive factors of RFL following LPN. The correlation between the m-CI and the operative time, ischemia time, and blood loss during LPN were also evaluated by the unpaired t-test. Results: Pearson's coefficient values between the postoperative RFL and the m-CI and C index were 0.294 and 0.173, respectively. In the multivariate analysis, the resected volume (p=0.031) and m-CI (p=0.036) significantly correlated with the postoperative RFL following LPN. The operative time (p<0.001), ischemia time (p=0.028), and blood loss (p=0.047) during LPN was significantly longer and larger, respectively, in the group with shorter m-CI (≤4.5) than in the group with the longer m-CI (>4.5). Conclusions:The present study demonstrates that the m-CI can predict RFL following LPN, as well as the surgical difficulty.

Roughness of the renal tumor surface could predict the surgical difficulty of robot‐assisted partial nephrectomy

“…Our clinical impression was that the shape and texture of the renal tumor surface might contribute to surgical difficulty and the surgical outcome of PN. Various scoring systems, including the R.E.N.A.L nephrometry score, PUDUA classification, C‐index scoring system, and contact surface area have been used to predict the surgical complexity and outcomes for renal tumors 6–9 ; however, none of them score the renal tumor smoothness or the shape. In this study, roughness of renal tumor surface was significantly associated with ischemia time and eGFR decrease rate, indicating that an irregular tumor surface required the surgeon to perform PN more cautiously and, subsequently, more time was required for tumor resection.…”

“…The assessment of reproducibility for judging of the roughness of renal tumor surface among three urologists showed the concordance rate was 77.8%. tumors [6][7][8][9] ; however, none of them score the renal tumor smoothness or the shape. In this study, roughness of renal tumor surface was significantly associated with ischemia time and eGFR decrease rate, indicating that an irregular tumor surface required the surgeon to perform PN more cautiously and, subsequently, more time was required for tumor resection.…”

Comparative study on the curative effect of laparoscopic nephron sparing surgery and renal functions under selective segmental renal artery clamping and main renal artery clamping

“…SSRAC not only can achieve a tumor supply vessel clamping effect 8 but also can effectively reduce patients' renal WIT and reduce renal injury risk. 9,10 In this study, LNSS under SSRAC was adopted to treat patients with T1 localized renal tumors and to evaluate its curative effect as well as renal function changes in the perioperative period.…”