Retroperitoneal Robot-Assisted Partial Nephrectomy for Posterior Renal Masses Is Associated with Earlier Hospital Discharge: A Single-Institution Retrospective Comparison

Transperitoneal vs retroperitoneal robotic partial nephrectomy: a meta-analysis and systematic review of propensity-matched studies

The main aim of this meta-analysis is to assess and compare the impact of two different surgical approaches, transperitoneal and retroperitoneal, on perioperative outcomes in robotic partial nephrectomy. A systematic search of MEDLINE, PubMed, Google Scholar, and the Cochrane Database was conducted to identify relevant studies published between January 2000 and January 2025. Included were nine non-randomized controlled trials with a total of 2420 patients with matching propensity scores. Among these patients, 1321 had robotic TPPN and 1099 had robotic RPPN, the abbreviation for robotic partial nephrectomy. Shorter operating times, shorter hospital stays, less estimated intraoperative blood loss, and fewer total postoperative problems were related to RPPN compared to TPPN. There were no notable disparities between the two groups when comparing the duration of renal ischemia, the fall in postoperative glomerular filtration rate (GFR), the occurrence of serious postoperative sequelae, or the necessity for blood transfusions. Compared to TPPN, RPPN demonstrates certain advantages in perioperative metrics such as surgical time, hospital stay, and overall complication rates. However, further high-quality studies are needed to confirm these findings.

Comparison of the perioperative outcomes of robot-assisted laparoscopic transperitoneal versus retraperitoneal partial nephrectomy for posterior-lateral renal tumors: a systematic review and meta-analysis

The study aims to assess the available literature and compare the perioperative outcomes of robotic-assisted partial nephrectomy (RAPN) for posterior-lateral renal tumors using transperitoneal (TP) and retroperitoneal (RP) approaches. Systematically searched the Embase, PubMed, and Cochrane Library databases for literature. Eligible studies were those that compared TP-RAPN and RP-RAPN for posterior-lateral renal tumors. The data from the included studies were analyzed and summarized using Review Manager 5.3, which involved comparing baseline patient and tumor characteristics, intraoperative and postoperative outcomes, and oncological outcomes. The analysis included five studies meeting the inclusion criteria, with a total of 1440 patients (814 undergoing RP-RAPN and 626 undergoing TP-RAPN). Both groups showed no significant differences in age, gender, BMI, R.E.N.A.L. score, and tumor size. Notably, compared to TP-RAPN, the RP-RAPN group demonstrated shorter operative time (OT) (MD: 17.25, P = 0.01), length of hospital stay (LOS) (MD: 0.37, P < 0.01), and lower estimated blood loss (EBL) (MD: 15.29, P < 0.01). However, no significant differences were found between the two groups in terms of warm ischemia time (WIT) (MD: -0.34, P = 0.69), overall complications (RR: 1.25, P = 0.09), major complications (the Clavien-Dindo classification ≥ 3) (RR: 0.97, P = 0.93), and positive surgical margin (PSM) (RR: 1.06, P = 0.87). The systematic review and meta-analysis suggests RP-RAPN may be more advantageous for posterior-lateral renal tumors in terms of OT, EBL, and LOS, but no significant differences were found in WIT, overall complications, major complications, and PSM. Both surgical approaches are safe, but a definitive advantage remains uncertain.

Robot-assisted single-port retroperitoneal partial nephrectomy with a novel purpose-built single-port robotic system with deformable surgical instruments

OBJECTIVE

To investigate the safety and feasibility of using a novel purpose-built single-port robotic system (the SHURUI Robotic Surgical System) with deformable surgical instruments to perform retroperitoneal single-port partial nephrectomy.

MATERIALS AND METHODS

A prospective study was conducted to recruit patients with a single renal tumor no more than 4 cm. Robot-assisted single-port partial nephrectomy was performed by using the novel purpose-built single-port robotic system with deformable surgical instruments. Patients' demographics, tumor characteristics, and perioperative parameters were recorded and analyzed.

RESULTS

Sixteen patients were recruited to the study. The median tumor size was 2.0 cm (IQR: 1.2-2.4 cm). The median R.E.N.A.L score was 6 (IQR: 4-4.5). In 3 cases, pure single-port surgery was carried out, and all the assistance was through the robotic port. Median docking time was 15.5 min (IQR: 14.25-22.25 min). Median operating time was 148.5 min (IQR: 178-238.5 min). Median console time was 107 min (IQR: 92.75-149.75 min). Median warm ischemic time was 26.5 min (IQR: 24.5-30 min). Median blood loss was 17.5 ml (IQR: 10-50 ml).

CONCLUSIONS

Retroperitoneal partial nephrectomy can be safely performed with this novel purpose-built single-port robotic system (SHURUI) with deformable surgical instruments. Further studies are needed to fully evaluate the role of this new platform.

Transperitoneal versus retroperitoneal robot-assisted partial nephrectomy: a systematic review and meta-analysis

INTRODUCTION

Robot-assisted partial nephrectomy (RAPN) can be performed either by a transperitoneal (TP) or a retroperitoneal (RP) approach. However, the superiority of one approach over the other is not established. Hence, the primary aim of this review was to compare perioperative outcomes between these two surgical approaches.

METHODS

Literature was systematically searched to identify studies reporting perioperative outcomes following TP RAPN and RP RAPN. The study protocol was registered with PROSPERO (CRD42023399496). The primary outcome was comparing complication rates between the two approaches.

RESULTS

This review included 22 studies, 5675 patients, 2524 in the RP group, and 3151 in the TP group. The overall complications were significantly lower in the RP group [Odds ratio (OR) 0.80 (0.67, 0.95), p = 0.01]. However, the rate of major complications was similar between the two groups. The operative time was significantly shorter with the RP group [Mean Difference (MD)-16.7 (- 22.3, - 11.0), p =  < 0.0001]. Estimated blood loss (EBL) and need for blood transfusion (BT) were significantly lower in the RP group. There was no difference between the two groups for conversion to radical nephrectomy [OR 0.66 (0.33, 1.33), p = 0.25] or open surgery [OR 0.68 (0.24, 1.92, p = 0.47] and positive surgical margins [OR 0.93 (0.66, 1.31, p = 0.69]. Length of stay (LOS) was shorter in the RP group [MD - 0.27 (- 0.45, - 0.08), p =  < 0.00001].

CONCLUSIONS

RP approach, compared to TP, has significantly lower complication rates, EBL, need for BT and LOS. However, due to the lack of randomized studies on the topic, further data is required.

Transperitoneal vs. Retroperitoneal Approach in Laparoscopic Partial Nephrectomy for Posterior Renal Tumors: A Retrospective, Multi-Center, Comparative Study

Purpose: The aim of our study is to compare the perioperative, functional, and oncological outcomes of laparoscopic transperitoneal partial nephrectomy (LTPN) and laparoscopic retroperitoneal partial nephrectomy (LRPN) for posterior cT1 renal tumors. Methods: We retrospectively collected data on all patients who consecutively underwent LTPN and LRPN for posterior cT1 renal tumors in three different centers from January 2015 to January 2023. Patients with a single, unilateral, cT1 renal mass, located in the posterior renal surface were included. Patients' data regarding perioperative, functional, and oncological outcomes were collected from medical records and statistically analyzed and compared. Results: A total of 128 patients was obtained, with 53 patients in the LPTN group and 75 patients in the LRPN group. Baseline characteristics were similar. Warm ischemia time (WIT) (18.8 vs. 22.6 min, p = 0.002) and immediate postoperative eGFR drop (-6.1 vs. -13.0 mL/min/1.73 m2, p = 0.047) were significantly lower in the LPTN group. Estimated blood loss (EBL) (100 vs. 150 mL, p = 0.043) was significantly lower in the LRPN group. All other perioperative and functional outcomes and complications were similar between the groups. The positive surgical margin (PSM) rate was lower in the LRPN group, although without statistical significance (7.2% vs. 13.5%, p = 0.258). Surgical success defined by Trifecta (WIT ≤ 25 min, no PSM, and no major postoperative complication) was similar between both approaches. Conclusions: LTPN has significantly shorter WIT and a significantly smaller drop in immediate eGFR when compared to LRPN for posterior renal tumors. On the other hand, LRPN has significantly less EBL than LTPN. LRPN demonstrated fewer PSMs than LTPN, albeit without statistical significance. In terms of overall surgical success, as defined by Trifecta, both approaches achieved similar results.

A comparison of perioperative outcomes of transperitoneal versus retroperitoneal robot-assisted partial nephrectomy: a systematic review

RAPN can be carried out via a transperitoneal or retroperitoneal approach. The choice between the two approaches is open to debate and usually based on surgeon preference. The perioperative outcomes of transperitoneal robot-assisted partial nephrectomy versus retroperitoneal robot-assisted partial nephrectomy were compared. A systematic review of the literature was performed up to May 2020, using PubMed, Cochrane, Scopus and Ovid databases. Articles were selected according to a search strategy based on PRISMA criteria. Only studies comparing TRAPN with RRAPN were eligible for inclusion. Eleven studies were included in the quantitative synthesis. Baseline demographics (age, BMI, ASA, tumour size, and RENAL nephrometry score), intraoperative data (operative time, estimated blood loss, and warm ischaemia time) and postoperative outcomes (major complications according to Clavien-Dindo, length of hospital stay (LOS) and positive surgical margin rate) were recorded. A total of 3139 patients were included (2052 TRAPN vs. 1087 RRAPN). There was no significant difference in demographic variables (age, BMI), tumour size (p = 0.06) nor the nephrometry score (p = 0.20) between the two groups. Operative time (p = 0.02), estimated blood loss (p < 0.00001) and LOS (p < 0.00001) were significantly lower in the RRAPN group. No differences were found in major postoperative complications (Clavien-Dindo > 3; p = 0.37), warm ischaemia time (p = 0.37) or positive surgical margins (p = 0.13). Future researchers must attempt to achieve adequately powered, expertise based, multi-surgeon and multi-centric studies comparing TRAPN and RRAPN. RRAPN gives similar outcomes to TRAPN. RRAPN is associated with reduced operative time and LOS. Ideally, surgeons should be familiar and competent in both RAPN approaches and adopt a risk-stratified and patient-centred individualised approach, dependent on the tumour and patient characteristics. RAPN is feasible via two approaches. The retroperitoneal approach seems to be associated with a shorter operation time and hospital stay.

Single-port vs multi-port robot-assisted renal surgery: analysis of perioperative outcomes for excision of high and low complexity renal masses

There is emerging but limited data assessing single-port (SP) robot-assisted surgery as an alternative to multi-port (MP) platforms. We compared perioperative outcomes between SP and MP robot-assisted approaches for excision of high and low complexity renal masses. Retrospective chart review was performed for patients undergoing robot-assisted partial or radical nephrectomy using the SP surgical system (n = 23) at our institution between November 2019 and November 2021. Renal masses were categorized as high complexity (7+) or low complexity (4-6) using the R.E.N.A.L. nephrometry scoring system. Adjusting for baseline characteristics, patients were matched using a prospectively maintained MP database in a 2:1 (MP:SP) ratio. For high complexity tumors (n = 12), SP surgery was associated with a significantly longer operative time compared to MP (248.4 vs 188.1 min, p = 0.02) but a significantly shorter length of stay (1.9 vs 2.8 days, p = 0.02). For low complexity tumors (n = 11), operative time (177.7 vs 161.4 min, p = 0.53), estimated blood loss (69.6.0 vs 142.0 mL, p = 0.62), and length of stay (1.6 vs 1.8 days, p = 0.528) were comparable between SP and MP approaches. Increasing nephrometry score was associated with a greater relative increase in operative time for SP compared to MP renal surgery (p = 0.07) using best of fit linear modeling. SP robot-assisted partial and radical nephrectomy is safe and feasible for low complexity renal masses. For high complexity renal masses, the SP system is associated with a significantly longer operative time compared to the MP technique. Careful consideration should be given when selecting patients for SP robot-assisted kidney surgery.

Long term experience of robotic retroperitoneal partial nephrectomy as the default approach in the management of renal masses: should the paradigm shift?

Although retroperitoneal surgery has demonstrated a better quality of recovery compared to transperitoneal routes, Retroperitoneal Robot Assisted Partial Nephrectomy (RRAPN) remains proportionally infrequent. As the boundaries of what is achievable robotically continue to be pushed, we present our experience at a high-volume tertiary referral centre that specialises in retroperitoneal surgery, exploring its feasibility as standard of care in the management of small renal masses. A prospective database of 784 RAPNs (2009-2020) was reviewed and 721 RRAPNs (92%) were performed at our centre. In our practice, we utilise a four-port approach to RRAPN. Patient, tumour and operative characteristics were assessed and both oncological outcomes and trifecta and pentafecta achievements were determined. Pentafecta was defined as achieving trifecta (negative surgical margin, no post-operative complications and WIT of < 25 min) plus over 90% estimated GFR preservation and no CKD stage upgrading at 1 year. Multivariate analysis was conducted to predict peri-operative factors which may prevent achieving a trifecta/pentafecta outcome. From 784 cases, 112 RAPNs were performed for imperative reasons, whilst the remainder were elective. Mean BMI ± s.d amongst our cohort was 28.6 ± 5.7. Mean tumour size was 3.1 cm (range 0.8-10.5 cm) and 47% of cases were stratified as intermediate/high risk using R.E.N.A.L nephrometry scoring. Forty-six patients had lesions in a hilar location, and 31% were anterior. Median blood loss was 30mls, with an open conversion rate of 1% and transfusion rate of 1.6%. Median warm ischaemic time (WIT) was 21 min, positive surgical margins were found in 4% and our post-operative Clavien 3/ > complication rate was 2.6%. We had a 1-day median length of stay with a 30 day readmission rate of 2%. Of 631 patients (80%) with a definitive histological diagnosis of cancer, 23% had T1b/ > disease. Over a mean 15 month follow-up period (range 1-125 months), 2% of patients developed recurrences and our cohort demonstrated a 99% 5 year cancer specific survival. Trifecta was achieved in 67% of cases and pentafecta in 47%. Age (p = 0.05), operative time (p = 0.008), pT1b tumours (p = 0.03), R.E.N.A.L score and blood loss (p = 0.001) were found to statistically significantly influence achievement of trifecta. Pentafecta achievement was influenced by R.E.N.A.L score (p = 0.008), operative time (p = 0.001) and blood loss (p = 0.001). We demonstrate the retroperitoneal approach in RAPN is feasible and safe irrespective of lesion location and complexity. In the hands of high-volume centres that are skilled in the retroperitoneal approach the benefits of retroperitoneal surgery can be extended even to challenging cohorts of patients without compromising their oncological or functional outcomes.

Comparison of Transperitoneal and Retroperitoneal Robotic Partial Nephrectomy for Patients with Completely Lower Pole Renal Tumors

(1) Background: For completely lower pole renal tumors, we compared the perioperative outcomes of robotic partial nephrectomy via transperitoneal and retroperitoneal approaches. (2) Methods: Complete lower pole renal tumors were defined as tumors that received 1 point for the “L” element of the R.E.N.A.L. and located at the lower pole of kidney. After confirming consistency in baseline characteristics, oncological and functional benefits were compared. Pentafecta achievement was used to represent the perioperative optimal outcome, followed by multivariate analysis of factors associated with the lack of pentafecta achievement. (3) Results: Among 151 patients identified, 116 (77%) underwent robotic partial nephrectomy via a transperitoneal approach and 35 (23%) via a retroperitoneal approach. Patients undergoing transperitoneal robotic partial nephrectomy experienced more blood loss than those undergoing retroperitoneal robotic partial nephrectomy (50 mL vs. 40 mL, p = 0.015). No significant differences were identified for operative time (120 min vs. 120 min), ischemia time (19 min vs. 20 min), positive surgical margins (0.0% vs. 2.86%), postoperative rate of complication (12.07% vs. 5.71%). No significant differences were identified in pathologic variables, eGFR decline in postoperative 12-month (3.9% vs. 5.4%) functional follow-up. Multivariate cox analysis showed that tumor size (OR: 0.523; 95% CI: 0.371−0.736; p < 0.001) alone was independently correlated to the achievement of pentafecta. (4) Conclusions: For completely lower pole renal tumors, transperitoneal and retroperitoneal robotic partial nephrectomy provide similar outcomes. These two surgical approaches remain feasible options for these cases.

Retroperitoneal Robot-assisted Partial Nephrectomy: A Systematic Review and Pooled Analysis of Comparative Outcomes

Context

Robot-assisted partial nephrectomy (RAPN) has gained increasing popularity as primary minimally invasive surgical treatment for localized renal tumors, and it has preferably been performed with a transperitoneal approach. However, the retroperitoneal approach represents an alternative approach given potential advantages.

Objective

To provide an updated analysis of the comparative outcomes of retroperitoneal RAPN (R-RAPN) versus transperitoneal RAPN (T-RAPN).

Evidence acquisition

A systematic review of the literature was performed up to September 2021 using MEDLINE, EMBASE, and Web of Science databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations. A sensitivity analysis was performed considering only matched-pair studies.

Evidence synthesis

Seventeen studies, which were published between 2013 and 2021, were retrieved. None of them was a randomized clinical trial. Among the 6,266 patients included in the meta-analysis, 2261 (36.1%) and 4,005 (63.9%) underwent R-RAPN and T-RAPN, respectively. No significant difference was found in terms of baseline features. The T-RAPN group presented a higher rate of male patients (odds ratio [OR]: 0.86, p = 0.03) and larger tumor size (weighted mean difference [WMD]: 0.2 cm; p = 0.003). The R-RAPN group reported more frequent posterior renal masses (OR: 0.23; p < 0.0001). The retroperitoneal approach presented lower estimated blood loss (WMD: 30.41 ml; p = 0.001), shorter operative time (OT; WMD: 20.36 min; p = 0.0001), and shorter length of stay (LOS; WMD: 0.35 d; p = 0.002). Overall complication rates were 13.7% and 16.05% in the R-RAPN and T-RAPN groups, respectively (OR: 1.32; p = 0.008). There were no statistically significant differences between the two groups regarding major (Clavien-Dindo classification ≥3 grade) complication rate, “pentafecta” achievement, as well as positive margin rates. When considering only matched-pair studies, no difference between groups was found in terms of baseline characteristics. Posterior renal masses were more frequent in the R-RAPN group (OR: 0.6; p = 0.03). Similar to the analysis of the entire cohort, R-RAPN reported lower EBL (WMD: 35.56 ml; p < 0.0001) and a shorter OT (WMD: 18.31 min; p = 0.03). Overall and major complication rates were similar between the two groups. The LOS was significantly lower for R-RAPN (WMD: 0.46 d; p = 0.02). No statistically significant difference was found between groups in terms of overall PSM rates.

Conclusions

R-RAPN offers similar surgical outcomes to T-RAPN, and it carries potential advantages in terms of shorter OT and LOS. Available evidence remains limited by the lack of randomized clinical trials.

Patient summary

In this review of the literature, we looked at comparative outcomes of two surgical approaches to robot-assisted partial nephrectomy. We found that the retroperitoneal technique offers similar surgical outcomes to the transperitoneal one, with potential advantages in terms of shorter operative time and length of hospital stay.

Comparison of Transperitoneal and Retroperitoneal Robotic Partial Nephrectomy for Patients With Complete Upper Pole Renal Tumors

OBJECTIVES

We compared the outcomes of transperitoneal robotic partial nephrectomy (TRPN) and retroperitoneal robotic partial nephrectomy (RRPN) for complete upper pole renal masses (1 point for the "L" component of the RENAL scoring system).

MATERIAL AND METHODS

We retrospectively reviewed patients who underwent either TRPN or RRPN from 2013 to 2016. Baseline demographics and perioperative, functional, and oncological results were compared. Multivariable analysis was performed to identify factors related to pentafecta achievement (ischemia time ≤25 min, negative margin, perioperative complication free, glomerular filtration rate (eGFR) preservation >90%, and no chronic kidney disease upstaging).

RESULTS

No significant differences between TRPN vs. RRPN were noted for operating time (110 vs. 114 min, p = 0.870), renal artery clamping time (19 vs. 18 min, p = 0.248), rate of positive margins (0.0% vs. 3.3%, p = 0.502), postoperative complication rates (25.0% vs. 13.3%, p = 0.140). TRPN was associated with a more estimated blood loss (50 vs. 40 ml, p = 0.004). There were no significant differences in pathologic variables, rate of eGFR decline for postoperative 12-month (9.0% vs. 7.1%, p = 0.449) functional follow-up. Multivariate analysis identified that only RENAL score (odd ratio: 0.641; 95% confidence interval: 0.455-0.904; p = 0.011) was independently associated with the pentafecta achievement.

CONCLUSIONS

For completely upper pole renal masses, both TRPN and RRPN have good and comparable results. Both surgical approaches remain viable options in the treatment of these cases.

The impact of a fellow on a regional robotic-assisted partial nephrectomy service

INTRODUCTION

Training a fellow has a cost in time and effort for the surgeon and their team. Their relative inexperience may also negatively affect the patient. The aim of this study was to determine and quantify the impact of a fellow on a regional robotic-assisted partial nephrectomy service and on perioperative outcomes.

MATERIALS AND METHODS

We reviewed the prospectively collected data for 522 patients who had undergone robotic-assisted partial nephrectomy since 2015 during the tenure of six fellows. Perioperative outcomes for three groups were compared: group A (no fellow participation), group B (some participation) and group C (fellow completed entire operation). We also reviewed progression over 12 months.

RESULTS

Demographics were similar in all groups apart from the percentage of men, which was lower in group C (p < 0.05). Operative time was 27 minutes longer for group B (p < 0.001). Warm ischaemia time was significantly shorter for group A but the difference was only four minutes (p < 0.001). Length of stay was slightly shorter for group C compared with the other groups (p < 0.01). Trifecta achievement was greatest for group A (p < 0.001). There were no perioperative deaths in any group and positive margins, complications and readmissions were low and similar in all groups. Towards the end of their fellowship, fellows performed more operations independently.

CONCLUSION

There is a measurable, but small, negative impact of a fellow on a robotic-assisted partial nephrectomy service, which reduces with experience. With appropriate supervision and patient selection, a fellow can be taught robotic-assisted partial nephrectomy without affecting patient safety or treatment outcome.

Renal Functional and Perioperative Outcomes of Retroperitoneal Robot-Assisted Versus Laparoscopic Partial Nephrectomy with Segmental Renal Artery Clamping

Background: Retroperitoneal approach and segmental renal artery clamping in partial nephrectomy are techniques that facilitate postoperative recovery and renal function preservation. This study aimed to compare the renal function preservation and perioperative outcomes of robot-assisted partial nephrectomy (RAPN) and laparoscopic partial nephrectomy (LPN) with these techniques. Materials and Methods: Clinical parameters of 43 patients who had undergone retroperitoneal RAPN from March 2017 to December 2019 were retrospectively collected and compared with those of 52 patients who had undergone retroperitoneal LPN at the same period in our institution. Differences in operating time, warm ischemia time, estimated blood loss, complications, postoperative hospital stay, as well as renal function loss were compared between the two groups. Results: Background characteristics between RAPN and LPN groups such as age, gender, BMI, and tumor characteristics were comparable. All RAPNs and LPNs were successfully completed without conversion to open surgery or nephrectomy. No significant difference in operating time, estimated blood loss, complications, and postoperative hospital stay was observed between RAPN and LPN groups. The warm ischemia time in RAPN group was slightly shorter than that of LPN groups (P = .054). Compared with the LPN group, the RAPN group was significantly associated with less glomerular filtration rate reduction and renal volume loss rate (P = .042 and P = .013, respectively). Conclusions: The perioperative outcomes were comparable between the two groups. However, compared with LPN, RAPN had superiority in preserving renal function in our series.

Retroperitoneal versus transepritoneal robot-assisted partial nephrectomy for postero-lateral renal masses: an international multicenter analysis

PURPOSE

To assess the outcomes of retroperitoneal robot-assisted partial nephrectomy (r-RAPN) in a large cohort of patients with postero-lateral renal masses comparing to those of transperitoneal RAPN (t-RAPN).

METHODS

Patients with posterior (R.E.N.A.L. score grading P) or lateral (grading X) renal mass who underwent RAPN in six high-volume US and European centers were identified and stratified into two groups according to surgical approach: r-RAPN ("study group") and t-RAPN ("control group"). Baseline characteristics, intraoperative, and postoperative data were collected and compared.

RESULTS

Overall, 447 patients were identified for the analysis. 231 (51.7%) and 216 (48.3%) patients underwent r-RAPN and t-RAPN, respectively. Baseline characteristics were not statistically significantly different between the groups. r-RAPN group reported lower median operative time (140 vs. 170 min, p < 0.001). No difference was found in ischemia time, estimated blood loss, and intraoperative complications. Overall, 47 and 54 postoperative complications were observed in r-RAPN and t-RAPN groups, respectively (20.3 vs. 25.1%, p = 0.9). 1 and 2 patients reported major complications (Clavien-Dindo ≥ III grade) in the retroperitoneal and transperitoneal groups (0.4 vs. 0.9%, p = 0.9). There was no difference in hospital re-admission rate, median length of stay, and PSM rate. Trifecta criteria were achieved in 90.3 and 89.2% of r-RAPN and t-RAPN, respectively (p = 0.7).

CONCLUSION

r-RAPN and t-RAPN offer similar postoperative, functional, and oncological outcomes for patients with postero-lateral renal tumors. Our analysis suggests an advantage for r-RAPN in terms of shorter operative time, whereas it does not confirm a difference in terms of length of stay, as suggested by previous reports.

Retroperitoneal or transperitoneal approach in robot-assisted partial nephrectomy, which one is better?

Purpose

To systematically assess the perioperative outcomes of retroperitoneal (RP) and transperitoneal (TP) approaches in robot‐assisted partial nephrectomy (RAPN), we conducted an updated meta‐analysis.

Methods

A literature retrieval of multi‐database including PubMed, Web of Science, Embase, Cochrane Library, and CNKI was performed to identify eligible comparative studies from the inception dates to January 2021. Perioperative outcomes included operative time (OT), estimated blood loss (EBL), warm ischemia time (WIT), postoperative length of stay (PLOS), positive surgical margin (PSM), and complications (major complications and overall complications). Outcomes of data were pooled and analyzed with Review Manager 5.4.1.

Results

Twenty‐one studies involving a total of 2482 RP and 3423 TP approach RAPN patients met the inclusion criteria. Operating time (OT) (weighted mean difference [WMD] −16.60; 95% confidence interval [CI] −23.08, −10.12; p < 0.01) and PLOS (WMD −0.46 days; 95% CI −0.69, −0.23; p < 0.01) were shorter in RP‐RAPN. Besides, lower EBL (WMD −21.67; 95% CI −29.74, −13.60; p < 0.05) was also found in RP‐RAPN. Meanwhile, no significant differences were found in other outcomes.

Conclusions

RP‐RARN was superior to TP‐RAPN in patients undergoing RAPN in terms of OT, PLOS, and estimated blood loss. Besides these two approaches have no significant differences in PSMs or perioperative complications.

The future of "Retro" robotic partial nephrectomy

Partial nephrectomy (PN) is the gold standard treatment for appropriately selected renal masses. Recent surgical advancements and adoption of the robotic technique has led to greater adoption of nephron-sparing surgery. Robotic PN was initially described via the transperitoneal (TP) approach, however, retroperitoneal (RP) access is possible and in some cases more desirable. In the RP approach, the kidney is accessed from its posterior surface and the intraperitoneal space is avoided. The RP approach to PN has the benefit of avoiding intraperitoneal viscera and colonic mobilization in patients with extensive prior abdominal surgery. The technique also eliminates the need for renal unit rotation in patients with posterior tumors and affords access to masses directly posterior to the renal hilum. The RP and TP approach to PN have shown similar oncologic and perioperative outcomes. Several recent studies have reported shorter operative times and lengths of stay (LOS) with comparable warm ischemia times for the RP approach when compared to transperitoneal PN (tPN). Given the indispensable deliverables of this approach in select patients, robotic retroperitoneal PN (rPN) should be in the armamentarium of a versatile urologic kidney surgeon. This review describes the current state of rPN and compares the indications and outcomes of the TP and RP approaches.

Comparison of Outcomes Between Transperitoneal and Retroperitoneal Robotic Partial Nephrectomy: A Meta-Analysis Based on Comparative Studies

Background

To compare perioperative, functional and oncological outcomes between transperitoneal robotic partial nephrectomy (TRPN) and retroperitoneal robotic partial nephrectomy (RRPN).

Methods

A literature searching of Pubmed, Embase, Cochrane Library and Web of Science was performed in August, 2020. Pooled odds ratios (ORs) or weighted mean differences (WMDs) with 95% confidence intervals (CIs) were estimated using fixed-effect or random-effect model. Publication bias was evaluated with funnel plots. Only comparative studies with matched design or similar baseline characteristics were included.

Results

Eleven studies embracing 2,984 patients were included. There was no significant difference between the two groups regarding conversion to open (P = 0.44) or radical (P = 0.31) surgery, all complications (P = 0.06), major complications (P = 0.07), warm ischemia time (P = 0.73), positive surgical margin (P = 0.87), decline in eGFR (P = 0.42), CKD upstaging (P = 0.72), and total recurrence (P = 0.66). Patients undergoing TRPN had a significant higher minor complications (P = 0.04; OR: 1.39; 95% CI, 1.01–1.91), longer operative time (P < 0.001; WMD: 21.68; 95% CI, 11.61 to 31.76), more estimated blood loss (EBL, P = 0.002; WMD: 40.94; 95% CI, 14.87 to 67.01), longer length of hospital stay (LOS, P < 0.001; WMD: 0.86; 95% CI, 0.35 to 1.37). No obvious publication bias was identified.

Conclusion

RRPN is more favorable than TRPN in terms of less minor complications, shorter operative time, less EBL, and shorter LOS. Methodological limitations of the included studies should be considered while interpreting these results.

Comparison of Therapeutic Effects Among Different Surgical Approaches in Robot-Assisted Partial Nephrectomy: A Systematic Review and Meta-Analysis

Purpose: To systematically explore the superiority of the transperitoneal approach in robot-assisted partial nephrectomy (TP-RAPN) and retroperitoneal approach in robot-assisted partial nephrectomy (RP-RAPN). Methods: Several databases were searched including PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, CBM, Wan Fang, and VIP to identify relevant studies that reported the comparison of the TP-RAPN and RP-RAPN. Outcomes of data were pooled and analyzed with Review Manager 5.3 to compare the intraoperative and postoperative variables and postoperative complications. Based on the heterogeneity of the studies, odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using a random-effect model or fixed-effect model. The sensitivity analysis and the subgroup analysis were used to minimize the effects of heterogeneity. And, publication bias was assessed by funnel plots. Results: In all, 16 studies met the inclusion criteria, including 2336 TP-RAPN patients and 1705 RP-RAPN patients. This meta-analysis reviewed 16 studies on RAPN, and the RP-RAPN showed shorter operative time (OT) (WMD 13.18 minutes; 95% CI 5.04-21.31; p = 0.001), shorter postoperative bowel function recovery (WMD 1.97 days; 95% CI 0.43-3.52; p = 0.01), shorter length of stay (LOS) (WMD 0.51 days; 95% CI 0.25-0.77; p = 0.0001), and lower estimated blood loss (EBL) (WMD 7.08 mL; 95% CI 1.41-12.74; p = 0.01) than the TP-RAPN. Additionally, no significant differences were found in other outcomes. Conclusions: In comparison, the RP-RAPN had significantly shorter OT, postoperative bowel function recovery time, LOS, and lower EBL. The RP-RAPN is associated with better value for posterior and laterally located tumors and is faster and equally safe and low costs for the patient.

Comparison of postoperative recovery after robot-assisted partial nephrectomy of T1 renal tumors through retroperitoneal or transperitoneal approach: A Japanese single institutional analysis

OBJECTIVE

To evaluate the quality of recovery in patients who underwent robot-assisted partial nephrectomy and to compare the outcomes of the transperitoneal or retroperitoneal approach.

METHODS

This study included 121 patients who underwent robot-assisted partial nephrectomy under general anesthesia from April 2019 to September 2019 at Tokyo Women's Medical University, Tokyo, Japan. Quality of recovery was defined according to the QoR-40 Japanese version. The participants responded to the QoR-40 Japanese version on three designated days. The patients were assigned to two groups according to the surgical approach: transperitoneal or retroperitoneal. A multivariate logistic regression analysis was carried out to identify independent factors associated with better quality of recovery.

RESULTS

Out of the 121 patients, 56 (46%) and 65 (54%) patients were included in the transperitoneal and retroperitoneal group, respectively. Although the QoR-40 Japanese version scores were not different between the two groups at admission, a better quality of recovery was observed in the retroperitoneal group than in the transperitoneal group at discharge based on the total score: physical comfort, emotional state, physical independence and pain. A multivariate analysis showed that the retroperitoneal approach and male sex were associated with a better QoR-40 Japanese version score at discharge.

CONCLUSIONS

A retroperitoneal approach offers better quality of recovery than a transperitoneal approach, and therefore it might represent the optimal approach in selected patients undergoing robot-assisted partial nephrectomy.

Retroperitoneal Versus Transperitoneal Robotic Partial Nephrectomy: A Multicenter Matched-pair Analysis

BACKGROUND

With increasing acceptance of robotic partial nephrectomy over the last decade, there is an ongoing discussion about the transperitoneal versus retroperitoneal access.

OBJECTIVE

To report outcomes after transperitoneal (TRPN) versus retroperitoneal (RRPN) robotic partial nephrectomy.

DESIGN, SETTING, AND PARTICIPANTS

A total of 754 patients were identified from the databases of three high-volume centers who underwent either TRPN (n = 551) or RRPN (n = 203).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Perioperative data were evaluated retrospectively. A propensity score matched-pair analysis was performed with the following variables: grade of renal insufficiency, age, body mass index, tumor diameter, and preoperative aspects and dimensions used for an anatomical (PADUA) score with a subsequent subgroup analysis for tumor location. For quality outcomes, the margin, ischemia, and complications (MIC) criteria were used (negative margins, ischemia time <20 min, and no major complications). Statistical analyses included chi-square and Mann-Whitney U tests.

RESULTS AND LIMITATIONS

In all, 176 patients could be matched in each group. The median tumor diameter was 28 mm with a PADUA score of 9. In 11% of RRPN versus 44% of TRPN cases, an anterior tumor location was found, and in 55% versus 30%, a posterior lesion was found (p < 0.001). Operative time (119 vs 139 min, p < 0.001) and warm ischemia time (9 vs 10 min, p = 0.003) were significantly shorter for RRPN. No significant differences were observed between intra- and postoperative complication rates, with 8% major complications in TRPN versus 3% in RRPN (p = 0.06). The MIC criteria were achieved in 90% in the RRPN versus 88% in the TRPN group, without differences for tumor location.

CONCLUSIONS

Significant differences between TRPN and RRPN could be found for intraoperative time, while complication rates and quality outcomes were comparable. RRPN can also be a considerable alternative for anterior tumors.

PATIENT SUMMARY

In this study, we demonstrate that robotic partial nephrectomy is feasible with either a transperitoneal or a retroperitoneal surgical access. The posterior approach can also be used for anterior renal tumors and may result in shorter operative time.

Comparisons of surgical outcomes between transperitoneal and retroperitoneal approaches in robot-assisted laparoscopic partial nephrectomy for lateral renal tumors: a propensity score-matched comparative analysis

OBJECTIVE

To compare the surgical outcomes between the transperitoneal (TP) and retroperitoneal (RP) approaches in robot-assisted laparoscopic partial nephrectomy (RAPN) for lateral tumors.

METHODS

This study included patients who underwent RAPN for lateral renal tumors between 2013 and 2019. Lateral tumors were defined as X of A factors in the RENAL nephrometry score. In total, 290 and 48 patients with TP and RP, respectively, were included in the analysis. To minimize the effects of selection bias, the following variables were adjusted using 1:1 propensity score matching: age, sex, body mass index, American Society of Anesthesiologists score, preoperative estimated glomerular filtration rate, tumor size, and RENAL nephrometry score.

RESULTS

After matching, 48 patients were allocated to each group. The mean age was 55 years, and the mean preoperative estimated glomerular filtration rate (eGFR) was 68-69 mL/min/1.73 m². The mean tumor size was 30-31 mm. The RP group had a shorter operative time (124 vs. 151 min, p = 0.0002), shorter console time (74 vs. 110 min, p < 0.0001), shorter warm ischemic time (14 vs. 17 min, p = 0.0343), lower estimated blood loss (EBL) (33 vs. 52 ml, p = 0.0002), and shorter postoperative length of hospital stay (PLOS) (3.3 vs. 4.0 days, p < 0.0001) than the TP group. The change in eGFR, incidence rate of perioperative complication, and positive surgical margin rate did not significantly differ between the two groups.

CONCLUSION

RP had better surgical outcomes, including shorter operative time, lower EBL, and shorter PLOS for lateral renal tumors, which may suggest that RP is the optimal approach for selected lateral renal tumors.

The Impact of Surgical Strategy in Robot-assisted Partial Nephrectomy: Is It Beneficial to Treat Anterior Tumours with Transperitoneal Access and Posterior Tumours with Retroperitoneal Access?

Available comparison of transperitoneal robot-assisted partial nephrectomy (tRAPN) and retroperitoneal robot-assisted partial nephrectomy (rRAPN) does not consider tumour's location. The aim of this study was to compare perioperative morbidity, and functional and pathological outcomes after tRAPN and rRAPN, with the specific hypothesis that tRAPN for anterior tumours and rRAPN for posterior tumours might be a beneficial strategy. A large global collaborative dataset of 1169 cT1-2N0M0 patients was used. Propensity score matching, and logistic and linear regression analyses tested the effect of tRAPN versus rRAPN on perioperative outcomes. No differences were observed between rRAPN and tRAPN with respect to complications, operative time, length of stay, ischaemia time, median 1-yr estimated glomerular filtration rate (eGFR), and positive surgical margins (all p>0.05). Median estimated blood loss and postoperative eGFR were 50 versus100ml (p<0.0001) and 82 versus 78ml/min/1.73 m² (p=0.04) after rRAPN and tRAPN, respectively. At interaction tests, no advantage was observed after tRAPN for anterior tumours and rRAPN for posterior tumours with respect to complications, warm ischaemia time, postoperative eGFR, and positive surgical margins (all p>0.05). The techniques of rRAPN and tRAPN offer equivalent perioperative morbidity, and functional and pathological outcomes, regardless of tumour's location. PATIENT SUMMARY: Robot-assisted partial nephrectomy can be performed with a transperitoneal or a retroperitoneal approach regardless of the specific position of the tumour, with equivalent outcomes for the patient.

A Multi-Institutional Propensity Score Matched Comparison of Transperitoneal and Retroperitoneal Partial Nephrectomy for cT1 Posterior Tumors

OBJECTIVE

To compare the perioperative and renal functional outcome between transperitoneal and retroperitoneal robotic partial nephrectomy (TP-RPN and RP-RPN) in the largest cohort to date of RP-RPN for posterior tumors.

METHODS

We identified 519 patients who met eligibility criteria and underwent TP-RPN (n = 357, 68.8%) or RP-RPN (n = 162, 31.2%) for a posteriorly located cT1 tumor. Patients were propensity score (PS) matched on preoperative and tumor-specific characteristics. Perioperative outcome and renal function outcome at median follow-up 22 months were compared.

RESULTS

Between the PS matched TP-RPN (n = 157, 50%) and RP-RPN (n = 157, 50%) patients, operative time (OT) (185.0 versus 157.0, P < .001) was longer in TP-RPN versus RP-RPN patients. No significant differences in ischemia time (P = .618), blood loss (P = .178), positive surgical margins (P = .501), overall postoperative complications (P = .861), or progression of chronic kidney disease stage at median 22 months (P = .599) were identified. Length of stay (LOS) was reduced in RP-RPN patients (P = .017), but was not different once an institution used a postoperative day (POD)-1 discharge protocol (P = .579). Operative times were similar between groups in patients with obesity (P = .293) or a cT1b renal mass (P = 908).

CONCLUSION

RP-RPN for posterior tumors resulted in reduced OT and a shorter LOS compared to TP-RPN. When surgeons aimed to routinely discharge patients on POD-1, the surgical approach did not influence LOS. Operative time was similar between RP and TP-RPN among patients with obesity or a cT1b renal mass. All other measures, including ischemia time, blood loss, margin rates, complications, and renal function, did not differ between the two approaches.

Retroperitoneal vs Transperitoneal Robot-assisted Partial Nephrectomy: Comparison in a Multi-institutional Setting

OBJECTIVES

To evaluate retroperitoneal robot-assisted partial nephrectomy (RAPN) against transperitoneal approach in a multi-institutional prospective database, after accounting for potential selection bias that may affect this comparison.

PATIENTS AND METHODS

Post-hoc analysis of the prospective arm of the Vattikuti Collective Quality Initiative database from 2014 to 2018. Six hundred and ninety consecutive patients underwent RAPN by 22 surgeons at 14 centers in 9 countries. Patients who had surgery at centers not performing retroperitoneal approach (n = 197) were excluded. Inverse probability of treatment weighting was done to account for potential selection bias by adjusting for age, gender, body mass index, comorbidities, side of surgery, location/size/complexity of tumor, renal function, American Society of Anesthesiologists score, and year of surgery. Operative and perioperative outcomes were compared between weighted transperitoneal and retroperitoneal cohorts.

RESULTS

Ninety-nine patients underwent retroperitoneal RAPN; 394 underwent transperitoneal RAPN. Hospital stay in days-median 3.0 (Interquartile range [IQR] 2.0-4.0) transperitoneal vs 1.0 (1.0-3.0) retroperitoneal; P < .001, and blood loss in mL-125 (50-250) transperitoneal vs 100 (50-150) retroperitoneal; P = .007-were lower in the retroperitoneal group. There were no differences in operative time (P = .6), warm ischemia time (P = .6), intraoperative complications (P = .99), conversion to radical nephrectomy (P = .6), postoperative major complications (P = .6), positive surgical margins (P = .95), or drop in estimated glomerular filtration rate (P = .7).

CONCLUSION

In a multi-institutional setting, both retroperitoneal and transperitoneal approach to RAPN have comparable operative and perioperative outcomes, except for shorter hospital stay with the retroperitoneal approach.

Simplified robot-assisted partial nephrectomy: step-by-step technique and perioperative outcomes

Controversies have been raised and still exist regarding several technical aspects of robot-assisted partial nephrectomy (RAPN). While the "perfect RAPN" has still to be determined, we aimed to report a simplified technique of RAPN in a step-by-step fashion and the perioperative outcomes of a single-center series. A simplified technique of RAPN was developed, refined and standardized over the past 7 years in an academic department of urology to make it as safe and as reproducible as possible, the main goal being to make it an "easy to learn" technique for fellows. This technique is presented in 12 key steps. The patients' characteristics and perioperative outcomes were prospectively collected and are reported herein. Since the first case performed in our department in 2010, 406 patients have undergone RAPN with a standardized and stable simplified technique after the first 30 cases, involving several key steps including systematic use of the transperitoneal approach, minimal visceral mobilization of the colon, systematic psoas exposure and ureter identification, minimal dissection of the perinephric fat, arterial clamping with early unclamping, no use of hemostatic agents or drain. The majority of RAPN were performed by surgeons with either low experience (i.e., < 20 procedures; 46.3%) or intermediate experience (i.e., 20-50 procedures; 17.2%). The mean warm ischemia time was 15.3 min. Conversions to an open approach and to radical nephrectomy were required in 14 (3.5%) and 21 (5.2%) cases, respectively. From 132 patients who experienced post-operative complications (32.5%), 47 experienced a major complication (11.6%). The positive surgical margin rate was 5.6%. The simplified technique of RAPN was feasible and reproducible with satisfactory perioperative outcomes. Most of the key steps have been assessed through single-center and multicenter clinical studies.

Retroperitoneal access for robotic renal surgery

Introduction and Objective

Retroperitoneal access for robotic renal surgery is an effective alternative to the commonly used transperitoneal approach. We describe our contemporary experience and technique for attaining retroperitoneal access.

Materials and Methods

We outline our institutional approach to retroperitoneal access for the instruction of urologists at the beginning of the learning curve. The patient is placed in the lateral decubitus position. The first incision is made just inferior to the tip of the twelfth rib as described by Hsu, et al. After the lumbodorsal fascia is traversed, the retroperitoneal space is dilated with a round 10 millimeter AutoSutureTM (Covidien, Mansfield, MA) balloon access device. The following trocars are used: A 130 millimeter KiiR balloon trocar (Applied Medical, Rancho Santa Margarita, CA), three robotic, and one assistant. Key landmarks for the access and dissection are detailed.

Results

177 patients underwent a retroperitoneal robotic procedure from 2007 to 2015. Procedures performed include 158 partial nephrectomies, 16 pyeloplasties, and three radical nephrectomies. The robotic fourth arm was utilized in all cases. When compared with the transperitoneal approach, the retroperitoneal approach was associated with shorter operative times and decreased length of stay (1). Selection bias and surgeon preference accounted for the higher proportion of patients who underwent partial nephrectomy off-camp via the retroperitoneal approach.

Conclusions

Retroperitoneal robotic surgery may confer several advantages. In patients with previous abdominal surgery or intra-abdominal conditions, the retroperitoneum can be safely accessed while avoiding intraperitoneal injuries. The retroperitoneum also provides a confined space that may minimize the sequelae of potential complications including urine leak. Moreover, at our institution, retroperitoneal robotic surgery is associated with shorter operative times and a decreased length of stay when compared with the transperitoneal approach (2). In selected patients, the retroperitoneal approach is a viable alternative to the transperitoneal approach for a variety of renal procedures.

Retroperitoneal approach for robot-assisted partial nephrectomy: technique and early outcomes

OBJECTIVES

The aim of our study is to present early outcomes of our series of retroperitoneal-RAPN (Robot Assisted Partial Nephrectomy).

MATERIALS AND METHODS

From September 2010 until December 2015, we performed 81 RAPN procedures (44 at left kidney and 37 at right). Average size was 3cm (1-9). Average PADUA score 7.1 (5-10). Average surgical time (overall and only robot time), ischemia time, blood loss, pathological stage, complications and hospital stay have been recorded.

RESULTS

All of the cases were completed successfully without any operative complication or surgical conversion. Average surgical time was 177 minutes (75-340). Operative time was 145 minutes (80-300), overall blood loss was 142cc (60-310cc). In 30 cases the pedicle was late clamped with an average ischemia time of 4 minutes (2-7). None of the patient had positive surgical margins at definitive histology (49pT1a, 12pT1b, 3pT2a, 2pT3a). Hospital stay was 3 days (2-7).

CONCLUSIONS

The retroperitoneal robotic partial nephrectomy approach is safe and allows treatment of even quite complex tumors. It also combines the already well known advantages guaranteed by the da Vinci® robotic surgical system, with the advantages of the retroperitoneoscopic approach.

Retroperitoneal Robotic Partial Nephrectomy: Systematic Review and Cumulative Analysis of Comparative Outcomes

OBJECTIVES

To compare the outcomes of retroperitoneal vs transperitoneal approach for robot-assisted partial nephrectomy (RAPN).

MATERIALS AND METHODS

A systematic review of the literature was performed through January 2018 using PubMed, Scopus, and Ovid databases. Article selection proceeded according to the search strategy based on PRISMA criteria. Only studies comparing retroperitoneal to transperitoneal approach for RAPN were deemed eligible for inclusion.

RESULTS

Seven retrospective case-control studies were identified and included in the analysis, with a total number of 1379 patients (866 for transperitoneal group; 513 for retroperitoneal group). In the retroperitoneal group, tumors were slightly larger [weighted mean difference (WMD): 0.29 cm; 95% confidence interval (CI): 0.04-0.54; p = 0.02], and more frequently located posterior/lateral (odds ratio: 0.61; 95% CI: 0.41-0.90; p = 0.01). In two of the studies only posterior tumors had been included. Both operating time (WMD 20.17 min; 95% CI 6.46-33.88; p = 0.004) and estimated blood loss (WMD 54.57 mL; 95% CI 6.73-102.4; p = 0.03) were significantly lower in the retroperitoneal group. In addition, length of stay was significantly shorter in the retroperitoneal group (WMD 0.46 days; CI 95% 0.15-0.76; p = 0.003). No differences were found regarding overall (p = 0.67) and major (p = 0.82) postoperative complications, warm ischemia time (p = 0.96), and positive surgical margins (p = 0.95).

CONCLUSIONS

Retroperitoneal RAPN can offer in select patients similar outcomes to those of the most common transperitoneal RAPN. Furthermore, it may be particularly advantageous for posterior upper pole and perihilar tumors and associated with reduction in operative time and hospital stay. Robotic surgeons should be ideally familiar with both approaches to adapt their surgical strategy to confront renal neoplasms from a position of technical advantage and ultimately optimize outcomes.

Frontiers in robot-assisted retroperitoneal oncological surgery

Robot assistance has been rapidly adopted by urological surgeons and has become particularly popular for oncological procedures involving the retroperitoneal space. The wide dissemination of robot assistance probably reflects the limited amount of operating space available within the retroperitoneum and the advantages provided by robot-assisted approaches, including 3D imaging, wristed instrumentation and the shorter learning curve compared with that associated with the equivalent laparoscopic techniques. Surgical procedures that have traditionally been performed using an open or laparoscopic approach, such as partial nephrectomy, radical nephrectomy, retroperitoneal lymph node dissection, nephroureterectomy and adrenalectomy, are now often being performed using robot assistance. The frontiers of robot-assisted retroperitoneal oncological surgery are constantly expanding, with an emphasis on maintaining oncological and functional outcomes, while minimizing the level of surgical invasiveness.

Robotic Partial Nephrectomy for Posterior Tumors Through a Retroperitoneal Approach Offers Decreased Length of Stay Compared with the Transperitoneal Approach: A Propensity-Matched Analysis

INTRODUCTION

We sought to compare surgical outcomes between transperitoneal and retroperitoneal robotic partial nephrectomy (RPN) for posterior tumors.

PATIENTS AND METHODS

Using our multi-institutional RPN database, we reviewed 610 consecutive cases for posterior renal masses treated between 2007 and 2015. Primary outcomes were complications, operative time, length of stay (LOS), surgical margin status, and estimated glomerular filtration rate (eGFR) preservation. Secondary outcomes were estimated blood loss, warm ischemia time (WIT), disease recurrence, and disease-specific mortality. Due to significant differences in treatment year and tumor size between approaches, retroperitoneal cases were matched 1:4 to transperitoneal cases based on propensity scores using the greedy algorithm. Outcomes were compared between approaches using the chi-square and Mann-Whitney U tests.

RESULTS

After matching, 296 transperitoneal and 74 retroperitoneal cases were available for analysis, and matched groups were well balanced in terms of treatment year, age, gender, race, American Society of Anesthesiologists physical status classification (ASA) score, body mass index, tumor laterality, tumor size, R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus, anterior/posterior, location relative to polar lines) score, and hilar location. Compared with transperitoneal, the retroperitoneal approach was associated with significantly shorter mean LOS (2.2 vs 2.6 days, p = 0.01), but longer mean WIT (21 vs 19 minutes, p = 0.01). Intraoperative (p = 0.35) and postoperative complications (p = 0.65), operative time (p = 0.93), positive margins (p = 1.0), and latest eGFR preservation (p = 0.25) were not significantly different between approaches. No differences were detected in the other outcomes.

CONCLUSIONS

Among high-volume surgeons, transperitoneal and retroperitoneal RPN achieved similar outcomes for posterior renal masses, although with slight differences in LOS and WIT. Retroperitoneal RPN may be an effective option for the treatment of certain small posterior renal masses.

Robotic Laparoendoscopic Single-site Retroperitioneal Renal Surgery: Initial Investigation of a Purpose-built Single-port Surgical System

BACKGROUND

Robotic single-site retroperitoneal renal surgery has the potential to minimize the morbidity of standard transperitoneal and multiport approaches. Traditionally, technological limitations of non-purpose-built robotic platforms have hindered the application of this approach.

OBJECTIVE

To assess the feasibility of retroperitoneal renal surgery using a new purpose-built robotic single-port surgical system.

DESIGN, SETTING, AND PARTICIPANTS

This was a preclinical study using three male cadavers to assess the feasibility of the da Vinci SP1098 surgical system for robotic laparoendoscopic single-site (R-LESS) retroperitoneal renal surgery.

SURGICAL PROCEDURE

We used the SP1098 to perform retroperitoneal R-LESS radical nephrectomy (n=1) and bilateral partial nephrectomy (n=4) on the anterior and posterior surfaces of the kidney. Improvements unique to this system include enhanced optics and intelligent instrument arm control. Access was obtained 2cm anterior and inferior to the tip of the 12th rib using a novel 2.5-cm robotic single-port system that accommodates three double-jointed articulating robotic instruments, an articulating camera, and an assistant port.

MEASUREMENTS

The primary outcome was the technical feasibility of the procedures, as measured by the need for conversion to standard techniques, intraoperative complications, and operative times.

RESULTS AND LIMITATIONS

All cases were completed without the need for conversion. There were no intraoperative complications. The operative time was 100min for radical nephrectomy, and the mean operative time was 91.8±18.5min for partial nephrectomy. Limitations include the preclinical model, the small sample size, and the lack of a control group.

CONCLUSIONS

Single-site retroperitoneal renal surgery is feasible using the latest-generation SP1098 robotic platform. While the potential of the SP1098 appears promising, further study is needed for clinical evaluation of this investigational technology.

PATIENT SUMMARY

In an experimental model, we used a new robotic system to successfully perform major surgery on the kidney through a single small incision without entering the abdomen.