A propensity score-matched comparison of surgical precision obtained by using volumetric analysis between robot-assisted laparoscopic and open partial nephrectomy for T1 renal cell carcinoma: a retrospective non-randomized observational study of initial outcomes.

Takagi, Toshio; Kondo, Tsunenori; Tachibana, Hidekazu; Iizuka, Junpei; Omae, Kenji; Kobayashi, Hirohito; Yoshida, Kazuhiko; Hashimoto, Yasunobu; Tanabe, Kazunari

PURPOSE We compared surgical outcomes between robot-assisted laparoscopic partial nephrectomy (RAPN) and open partial nephrectomy (OPN) by using volumetric analysis in a propensity score-matched analysis. METHODS We analyzed the records of 279 patients with normal contralateral kidneys who underwent RAPN or OPN for T1 renal tumors between 2012 and 2014. Volumetric studies to assess the vascularized parenchymal volume of the operated kidney were performed 2 months preoperatively and 6 months postoperatively. Patient data, including age, body mass index, presence of hypertension and/or diabetes mellitus, American Society of Anesthesiologists score, tumor size, preoperative estimated glomerular filtration rate, and tumor complexity using the renal nephrometry score, were matched 1:1 using propensity score matching between groups. RESULTS This cohort included 100 patients who underwent RAPN and 179 who underwent OPN. After matching, 48 patients were included in each group. Mean tumor diameter was 31 mm, and about 14 % were high-complexity tumors (RENAL score 10-12). The RAPN and OPN groups showed no significant differences in the rate of preservation of global renal function (95 vs. 92 %) and parenchymal volume of the operated kidney (84 vs. 79 %). Similarly, urological complications did not significantly differ between groups. Surgical margins were negative in all tumors. Patients who underwent RAPN had lower estimated blood loss (p < 0.0001) and shorter postoperative length of hospital stay (p < 0.0001) than those who underwent OPN. CONCLUSION RAPN can offer acceptable surgical outcomes and precision, compared to OPN, with decreased estimated blood loss and hospital stay.