Preoperative Risk Factor Analysis of Prolonged Retroperitoneoscopic Radical Nephrectomy

Background: This study aimed to investigate the preoperative risk factors for prolonged operating time in retroperitoneoscopic radical nephrectomy (RRN) for renal cell carcinoma (RCC). Methods: We retrospectively reviewed patients treated for RRN between January 2015 and December 2021. Clinical data, including radiological findings such as visceral fat area (VFA), subcutaneous fat area (SFA), and posterior perirenal fat thickness (PFT) were collected. The operating time for RRN was analyzed using univariate and multivariate logistic regression analyses. Results: A total of 79 patients were included. The median age was 66 (range: 28-88) years and 48 (60.8%) had right-sided tumors. The median tumor size was 52 (range: 12-100) mm. Median BMI, VFA, SFA, and posterior PFT were 22.9 (range: 16.3-42.2) kg/m2, 102 (range: 14-290) cm2, 124 (range: 33-530) cm2, and 6 (range: 1-35) mm. The median operating time was 248 (range: 140-458) min. Univariate logistic regression analyses revealed that a right tumor (p=0.046), tumor size >7 cm (p=0.010), and posterior PFT >25 mm (p=0.006) were preoperative risk factors for prolonged operating time in RRN. Multivariate logistic regression analyses revealed that a posterior PFT of >25 mm was an independent preoperative risk factor for prolonged operating time for RRN (p=0.008, OR: 7.29, 95% CI: 1.69-31.5). Conclusions: A posterior PFT >25 mm was an independent preoperative risk factor for the operating time of RRN. In RRN, for patients with a posterior PFT >25 mm, surgeons should develop surgical strategies, including the selection of a transperitoneal approach to surgery, to avoid prolonging the operating time.