Transperitoneal versus retroperitoneal single-port robot-assisted partial nephrectomy: systematic review and meta-analysis of perioperative and functional outcomes

Clinical Snapshot

Key Findings

• P Value: Blood loss: p=0.018; Hospital stay: p<0.001; Postoperative eGFR: p=0.001; Operative time (primary): p=0.356

• Effect Size: Blood loss: WMD +27.95 mL (TP vs RP); Hospital stay: WMD +0.56 days (TP vs RP); Postoperative eGFR: WMD +6.87 mL/min/1.73m² (TP vs RP, favouring TP for absolute eGFR preservation)

• Primary Outcome: Intraoperative blood loss, length of hospital stay, and postoperative eGFR were significantly higher in the transperitoneal group compared with the retroperitoneal group. Warm ischaemia time, positive surgical margin rate, operative time (primary analysis), and overall complication rate did not differ significantly between approaches.

• Nnt Or Sensitivity: No NNT calculable from continuous outcome data. Sensitivity analysis confirmed robustness of blood loss and hospital stay findings; operative time sensitivity analysis suggested a possible ~12-minute difference (RP faster) requiring prospective confirmation. Heterogeneity reported as low across primary outcomes.

• Confidence Interval: Blood loss: 95% CI 4.90–51.02 mL; Hospital stay: 95% CI 0.34–0.78 days; Postoperative eGFR: 95% CI 2.65–11.10 mL/min/1.73m²

Clinical Application

SP-RAPN with either approach requires advanced robotic surgical expertise and is currently limited to high-volume tertiary centres with the da Vinci SP system. The marginal differences in blood loss (~28 mL) and hospital stay (~0.5 days), while statistically significant, are of uncertain clinical significance in routine practice. The higher absolute postoperative eGFR in the TP group likely reflects baseline differences (larger/better-functioning kidneys with anteriorly located tumours) rather than a true approach benefit. In Australia, robotic-assisted partial nephrectomy is performed at major tertiary referral centres, predominantly using multi-port platforms. The da Vinci SP system has limited but growing availability in Australia, with TGA regulatory approval for urological procedures. SP-RAPN is not yet standard of care in Australian urology practice. The RACGP and Urological Society of Australia and New Zealand (USANZ) do not currently have specific guidelines for SP-RAPN approach selection. PBS funding does not separately itemise robotic surgical approaches; MBS item numbers for partial nephrectomy (e.g., item 36533) apply regardless of platform. Surgeons considering SP-RAPN should be guided by tumour anatomy, institutional expertise, and patient factors rather than this preliminary comparative evidence. Participation in prospective registries or RCTs is encouraged. Adult patients with localised renal tumours (clinical T1, likely T1a/T1b) who are candidates for nephron-sparing surgery at centres with established SP-RAPN programmes. Approach selection is strongly influenced by tumour location (posterior/retroperitoneal tumours favouring RP; anterior/upper pole tumours favouring TP), and this confounding must be considered when interpreting comparative outcomes.

Abstract

To systematically compare the safety and efficacy of the transperitoneal (TP) and retroperitoneal (RP) approaches in single-port robot-assisted partial nephrectomy (SP-RAPN). PubMed, Web of Science, and Embase were searched for comparative studies published before October 2025. The primary evaluated outcomes were grouped as Perioperative Outcomes (operative time, blood loss, ischemia time, positive surgical margin, postoperative eGFR, and hospital stay) and Surgical Safety (complication rate). Study inclusion and exclusion standards followed the PICOS guidelines. Four comparative studies with 384 patients (188 TP and 196 RP) were analyzed. Compared with the RP group, the TP group had higher intraoperative blood loss (WMD = 27.95 mL, 95% CI = 4.90-51.02, p = 0.018), longer hospital stay (WMD = 0.56 days, 95% CI = 0.34-0.78, p < 0.001), and higher absolute postoperative eGFR (WMD = 6.87, 95% CI = 2.65-11.10, p = 0.001). Operative time did not differ significantly in the main analysis (p = 0.356); an exploratory sensitivity analysis suggested a possible small difference (≈ 12 min) that requires confirmation. Warm ischemia time, positive surgical margin rate, and complication rate showed no significant differences between the two groups. Sensitivity analysis confirms the robustness of these findings, with overall low heterogeneity. Both transperitoneal and retroperitoneal SP RAPN are safe and feasible based on this limited evidence. Preliminary findings suggest the RP approach may offer advantages in blood loss, hospital stay, and renal preservation, but these results are hypothesis generating. Importantly, tumor location strongly influenced approach selection, and observed differences may be attributable to tumor location rather than the approach itself; causal inference is not possible from this observational data. Validation in larger, prospective, and preferably randomized studies is required.

References

1. 1.Yang, J., Liu, J., Mei, J., Wang, Z., Wang, K., & Guo, J. (2026). Transperitoneal versus retroperitoneal single-port robot-assisted partial nephrectomy: systematic review and meta-analysis of perioperative and functional outcomes. Journal of Robotic Surgery. https://doi.org/10.1089/end.2018.0211