Early Postoperative Outcomes of Retroperitoneal Partial Nephrectomy of Anterior and Posterior Renal Tumors: A 5-Year Experience in A Single Center.

Objective: Partial nephrectomy (PN) is one of the surgical treatment options for renal tumors. Therefore, the aim of this study was to compare the surgical outcomes of retroperitoneal PN for anterior and posterior tumors. Materials and Methods: This study enrolled 177 patients who had renal tumors that were detected on abdominal computed tomography and underwent PN between January 2017 and April 2021. Tumor position was defined by the anatomic avascular Brodel's line. Surgical outcomes were compared between approaches using the chi-squared Student's t -tests, logistic regression analysis, and stratification analysis. Results: Of the 177 patients, 97 (54.8%) patients had anterior renal tumors and 80 (45.2%) had posterior renal tumors. On comparing the surgical results between the two groups, the anterior group had higher levels of hemoglobin (Hb) reduction (-1.92 vs -1.54 g/dL, p  = 0.0444), but the estimated blood loss showed no significant difference between the two groups (497.6 vs 433.2 mL, p  = 0.4149). In addition, the alteration in estimated glomerular filtration rate at postoperative 1st day ( p  = 0.5616), 6th month ( p  = 0.5046), and at postoperative 1st year ( p  = 0.7085) was not significantly different between the two groups. Other surgical outcomes, such as blood transfusion rate, complications, and lengths of stay, also had no significant difference. Stratified analysis revealed the anterior renal tumors had a 3.76 times risk ( p  = 0.0186) than the posterior tumors for decreasing Hb >10% under laparoscopic PN. No postoperative gastrointestinal-related complications were reported. Conclusions: This study demonstrated retroperitoneal surgical access to renal tumors and revealed equivalent surgical outcomes for both anterior and posterior renal tumors. Moreover, anterior renal tumors had benefits under robotic PN for bleeding control. Retroperitoneal PN can be considered as a good approach for both anterior and posterior renal tumors with few intra-abdominal complications.