Comparison of perioperative outcomes of robot-assisted partial nephrectomy and open partial nephrectomy in patients with a solitary kidney

Purpose: To compare the perioperative outcomes of robot-assisted partial nephrectomy (RAPN) with open partial nephrectomy (OPN) in solitary kidneys.

Methods: Records of 1542 consecutive RAPN performed in five high-volume centers (2007-2013) were reviewed for patients with solitary kidneys. Results were compared with solitary OPN cases performed during the same period. Cases were divided into simple (R.E.N.A.L. nephrometry score 4-8) and complex (R.E.N.A.L. 9-12) groups. Demographics, surgical, pathologic, and follow-up data were compared between OPN and RAPN in each group.

Results: 40 RAPN and 85 OPN cases were identified. For both tumor complexity groups, patients in each treatment modality were comparable. There were higher proportions of OPN cases in the complex group (61.2% vs 25%; P=0.001). For both complexity tumor groups, there was no statistical difference between the treatment modalities in overall intraoperative/postoperative complications, transfusion rate, and positive surgical margin (PSM) rates. Patients in the RAPN group had a shorter length of hospital stay. For the entire cohort, there was no difference in estimated glomerular filtration rate preservation beyond 1 month (OPN 80.51%, RAPN 81.29%). Limitations include retrospective, nonrandomized nature of the series and small number of cases in the RAPN groups.

Conclusions: In the solitary kidney, RAPN offers comparable perioperative and short-term functional outcomes for localized tumors with low R.E.N.A.L. score. For more complex tumors, our early experience suggests comparability, but these results were obtained in selected cases and future studies will need to validate these results.