Robot-assisted partial nephrectomy: Can retroperitoneal approach suit for renal tumors of all locations?-A large retrospective cohort study

A Predictive Model for Surgical Approach Selection in Robotic Partial Nephrectomy and Its Perioperative Outcomes Based on Single-Center Retrospective Data

OBJECTIVES

To compare the perioperative and postoperative outcomes of transperitoneal and retroperitoneal robotic partial nephrectomy (RPN) and develop a prediction model for reference to select the approach.

MATERIALS AND METHODS

We retrospectively reviewed our single-institutional RPN database. The patients were divided into training and validation sets. In training set, transperitoneal and retroperitoneal cases were matched using propensity score matching to balance confounding factors. The intraoperative and postoperative outcomes of both approaches were compared. A prediction model was constructed to predict the probability of the retroperitoneal approach. The model was then externally validated using the data from the validation set.

RESULTS

A total of 318 patients were included in the training set, and after propensity score matching, 200 cases were left. Additionally, 92 patients were included in the validation set. The estimated blood loss (p = 0.021) and the hemoglobin change (p = 0.016) were greater in the transperitoneal group. There was no significant difference in operative time (p = 0.539), warm ischemia time (p = 0.678), hospitalization time (p = 0.673), extubation time (p = 0.621), creatinine change (p = 0.623), negative margin (p = 1), local recurrence (p = 1), postoperative complication (p = 0.229), long-term creatinine (p = 0.158), and overall survival (p = 0.671) between the two groups. Tumor diameter, anteroposterior location, longitudinal location, and accessory renal artery were employed as variables to construct the prediction model, resulting in area under the curve values of 0.84 and 0.77, respectively, during internal and external validation.

CONCLUSIONS

Retroperitoneal and transperitoneal approaches of RPN showed no difference in perioperative outcomes except estimated blood loss and hemoglobin change. The retroperitoneal approach is recommended for smaller tumors located in the upper pole or posterior and the presence of an accessory renal artery. Our model is available to predict the probability of the retroperitoneal approach.

A Systematic Review of Surgical Outcomes: Comparing Robotic-Assisted Partial Nephrectomy and Open Partial Nephrectomy in Nephron-Sparing Surgery for Renal Tumors

A partial nephrectomy is a critical approach for nephron-sparing surgery in renal tumors, striking a balance between oncological control and the preservation of renal function. Surgeons traditionally view open partial nephrectomy (OPN) as the gold standard in kidney surgery. The emergence of robotic-assisted partial nephrectomy (RAPN) offers a minimally invasive alternative that can improve surgical precision and decrease the risk of complications during the perioperative period. This systematic review analyzes and compares OPN and RAPN based on factors such as oncological effectiveness, preservation of kidney function, perioperative outcomes, and complication rates. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to review and include studies, analyzing 30 studies that involved more than 26,826 patients. The research team carried out retrospective and prospective cohort studies and randomized controlled trials (RCTs). They measured the quality of these studies by using the Newcastle-Ottawa Scale (NOS) for observational studies and the Cochrane Risk of Bias tool version 2 (RoB 2; Cochrane, London, UK) for RCTs. Our findings indicate that RAPN offers significant perioperative advantages, such as reduced mean estimated blood loss (EBL) of 181 mL compared to 284 mL for OPN and shorter hospital stays averaging three days compared to six days for OPN. Follow-up durations ranged from three to 60 months. Although the surgery for RAPN takes longer, it consistently preserves renal function better, resulting in less considerable declines in the estimated glomerular filtration rate (eGFR). Oncological outcomes show that RAPN achieves a negative surgical margin (NSM) rate of 97.16%, while OPN reaches 92%. RAPN effectively handles complex renal tumors, especially those with high Preoperative Aspects and Dimensions Used for Anatomical (PADUA) or R.E.N.A.L. Nephrometry score (Radius (R), Exophytic/Endophytic properties (E), Nearness to the collecting system or sinus (N), Anterior/Posterior location (A), Location relative to polar lines (L)). In conclusion, RAPN offers significant advantages in perioperative and functional outcomes while maintaining oncological equivalence to OPN. This seals RAPN as the preferred approach in centers with robotic expertise. However, OPN remains a viable option in low-resource settings. Future research should improve access to robotic systems, standardize reporting metrics, and conduct long-term randomized trials to understand both techniques' strengths and limitations better.

Concordance between renal tumour biopsy and robotic-assisted partial and radical nephrectomy histology: a 10-year experience

We aimed to assess concordance between renal tumour biopsy (RTB) and surgical pathology from robotic-assisted partial nephrectomy (RAPN) or robotic-assisted radical nephrectomy (RARN). Patients with preoperative RTB undergoing RAPN or RARN for suspected malignancy (9 September 2013-9 September 2023) were enrolled retrospectively from three sites. Patients were excluded if the tumour had prior cryotherapy or if biopsy or nephrectomy histology were unavailable or inconclusive. The primary outcome was concordance with the presence/absence of malignancy. Secondary outcomes were concordance with tumour subtype, World Health Organisation nuclear grade (patients with RTB clear cell or papillary RCC only), false-negative rate, false-positive rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In the enrolment period, 332 and 132 patients underwent RAPN and RARN, respectively. Of these, 160 received preoperative RTB, with nine patients excluded, leaving 151 eligible patients. Median age was 63 years, and 49 (32%) were female. On surgical specimens, 144 patients had malignant histology. RTB was highly concordant with presence/absence of malignancy (147/151, 97%). Concordance with tumour subtype occurred in 141 patients (93%), while concordance with nuclear grade was seen in 42/66 patients (64%, RTB grade missing in 53 patients). False-negative rate, false-positive rate, sensitivity, specificity, PPV, and NPV were 2%, 14%, 98%, 86%, 99%, and 67%, respectively. Limitations include absence of complication data and exclusion of patients biopsied without surgery. In patients undergoing RAPN or RARN, preoperative RTB has high concordance with surgical pathology, both in the presence of malignancy and RCC subtype.

Early outcomes of robotic retroperitoneal partial nephrectomy: evaluating surgical success with margin, ischemia, and complication score

OBJECTIVE

The objective of this study was to evaluate the minimum number of required cases for successful robotic retroperitoneal partial nephrectomy for an experienced surgeon in transperitoneal robotic surgery.

METHODS

Our prospectively collected clinic database was evaluated retrospectively, and 50 patients who underwent robotic retroperitoneal partial nephrectomy by a single experienced surgeon from January 2019 to February 2023 were included in this study. Demographic and perioperative data and R.E.N.A.L. nephrometry scores were noted. margin, ischemia, and complication score was used to predict surgical success. Receiver operating characteristic curve analysis was used to determine how many cases were required to achieve margin, ischemia, and complication score positivity and to apply the off-clamp technique. Also, the first 25 patients were assigned to Group 1 and the second 25 patients to Group 2, and the data were compared between the groups.

RESULTS

The patients' demographic data and tumor characteristics were similar in the groups. The off-clamp technique and sutureless technique rates in Group 2 were significantly higher than that in Group 1. Margin, ischemia, and complication score positivity was observed in 60% (n=15) of Group 1 and 96% (n=24) of Group 2. At receiver operating characteristic curve analysis, the 25th and later cases were statistically significant in terms of margin, ischemia, and complication score positivity. In terms of performing surgery with the off-clamp technique, the 28th and subsequent cases were statistically significant.

CONCLUSION

A total of 25 or more cases appear to be sufficient to provide optimal surgical results in robotic retroperitoneal partial nephrectomy for an experienced surgeon.