Perioperative outcomes of robotic partial nephrectomy for intrarenal tumors

Impacts of completely endophytic renal masses on perioperative, oncologic, and functional outcomes in robot-assisted partial nephrectomy: a systematic review and meta-analysis

Background

The objective of this study was to perform a comprehensive pooled analysis aimed at comparing the efficacy and safety of robot-assisted partial nephrectomy (RAPN) between completely endophytic tumors (CERT) and non-completely endophytic tumors (non-CERT).

Methods

This study adhered rigorously to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct a systematic review and meta-analysis. We performed a systematic search in the PubMed, Embase, Web of Science, and Cochrane Library databases, focusing on studies published in English up to May 2024. Our analysis primarily evaluated key outcomes, specifically perioperative, functional, and oncological outcomes.

Results

A total of 2126 patients across six studies were included in the analysis. Compared to non-CERT, CERT was associated with significantly higher rates of major complications (Odds Ratio [OR]: 2.47; 95% CI: 1.14 to 5.34; p = 0.02), longer warm ischemia times (Weighted Mean Difference [WMD]: 3.27 min; 95% CI: 0.61 to 5.39; p = 0.02), a greater decline in estimated glomerular filtration rate (eGFR) (WMD: 2.93 ml/min/1.73 m2; 95% CI: 0.75 to 5.11; p = 0.008), and relatively lower trifecta achievement rates (OR: 0.63; 95% CI: 0.41 to 0.96; p = 0.03). However, no statistically significant differences were observed between the two groups in terms of operative time, length of stay, blood loss, transfusion rates, intraoperative complications, overall complications, positive surgical margins, and local recurrence.

Conclusions

Although CERT was associated with greater declines in eGFR and lower rates of trifecta achievement, it yielded perioperative, functional, and oncologic outcomes comparable to those of non-CERT in RAPN. Our findings suggest that RAPN for completely endophytic renal masses can achieve acceptable outcomes when performed in centers with substantial expertise in robotic surgery.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=555067, identifier CRD42024555067.

Impacts of Complete Endophytic Renal Tumors on Surgical, Functional, and Oncological Outcomes of Robot-Assisted Partial Nephrectomy

Objective: Complete endophytic renal tumors (CERTs) are the most challenging for robot-assisted partial nephrectomy (RAPN). This study aimed to determine the impact of CERT on outcomes of RAPN. Methods: All RAPN cases for localized renal tumor undertaken at Yokohama City University Hospital between 2016 and 2023 were enrolled. Tumor characteristics and surgical, functional, and oncologic outcomes of RAPN were compared between CERT and non-CERT groups. Results: Consecutive 666 patients were enrolled, and 76 (11.4%) were identified as CERT (3 points of "E" score). CERT showed smaller tumor diameters (p < 0.001), more predominant hilar tumor (p = 0.029), higher "N" scores (p < 0.001) and "L" scores (p = 0.006) than non-CERT. The CERT group showed longer warm ischemia times (p < 0.001), more frequent positive surgical margins (p = 0.028), and relatively lower trifecta achievement rates (p = 0.101) than the non-CERT group. In multivariable analysis, the CERT was an independent predictor for trifecta achievement but not for pentafecta achievement. Conclusions: CERT was associated with longer warm ischemia time, positive surgical margin, and lower trifecta achievement, but not with surgical complication and pentafecta achievement in RAPN. This study suggested that CERT had limited influence on long-term renal functional preservation; however, it had strong impacts on short-term surgical outcome.

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications: Large tumors (cT2-T3), solitary kidney, completely endophytic, hilar, recurrent, and multiple renal tumors

Objective

Robot-assisted partial nephrectomy (RAPN) has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses. The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses, large tumors (cT2-T3), renal cell carcinoma in solitary kidney, recurrent tumors, completely endophytic and hilar masses, and simultaneous and multiple tumors.

Methods

A comprehensive search in the PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers. The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered. The secondary endpoint was to evaluate the surgical and functional outcomes.

Results

After screening 1250 records, 43 full-text manuscripts were selected, comprising over 8500 patients. Twelve and thirteen studies reported data for endophytic and hilar renal masses, respectively. Five and three studies reported outcomes for cT2-T3 and solitary kidney patients, respectively. Four studies focused on redo-RAPN for recurrent tumors. Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.

Conclusion

Over the past decade, evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown. Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes, the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result. Certainly, a higher likelihood of complication might be expected when facing extremely challenging cases. However, none of these indications should be considered per se an exclusion criterion for performing RAPN. Ultimately, a risk-adapted approach should be employed.

Treatment of bilateral Wilms' tumor in children: how to improve the application of nephron-sparing surgery

PURPOSE

To summarize the experience of nephron-sparing surgery (NSS) for bilateral Wilms tumors (BWT) in children.

METHODS

This study included children with BWT admitted to our hospital between January 2008 and June 2022. The details of the treatments and outcomes were analyzed.

RESULTS

In all, 70 patients (39 males and 31 females) were enrolled, including 66 patients with synchronous tumors and 4 patients with metachronous tumors. The median age at diagnosis was 13 (3-75) months. Overall, 59 patients received preoperative chemotherapy and 45.8% (54/118) of the 118 sides of WT achieved a partial response (PR). Of the 70 patients, 48 (68.6%) underwent bilateral NSS and 22 (31.4%) underwent unilateral NSS and contralateral total nephrectomy. The proportion of bilateral NSS in the preoperative chemotherapy group was significantly higher than in the non-chemotherapy group (P = 0.031). Additionally, there were 26, 25, 14, and 5 cases of stage I, stage II, stage III, and stage IV, respectively. Among the 70 children, 16 had a recurrence, and 8 died. The 4 years EFS and OS were 67.9% and 89.3%, respectively.

CONCLUSIONS

The long-term survival rates of patients with BWT improved. Hence, preoperative chemotherapy should be administered to enhance the use of NSS in BWT.

Outcomes of robot-assisted partial nephrectomy for completely endophytic renal tumors: A multicenter analysis

INTRODUCTION

Multicenter retrospective analysis of robotic partial nephrectomy for completely endophytic renal tumors (i.e. 3 points for the 'E' domain of the R.E.N.A.L. nephrometry score) was performed.

MATERIALS AND METHODS

Patients' demographics, tumor characteristics, perioperative, functional, pathological and oncological data were analyzed and compared with those of patients with exophytic and mesophytic masses (i.e. 1 and 2 points for the 'E' domain, respectively). Multivariable logistic regression analysis was used to assess variables for trifecta achievement (negative margin, no postoperative complications, and 90% estimated glomerular filtration rate [eGFR] recovery).

RESULTS

Overall, 147 patients were included in the study group. Patients with a completely endophytic mass had bigger tumors (mean 4.2 vs. 4.1 vs. 3.2 cm; p < 0.001) on preoperative imaging and higher overall R.E.N.A.L. score. There was no difference in mean operative time. Estimated blood loss was higher in the endophytic group (mean 177.75 vs. 185.5 vs. 130 ml; p = 0.001). Warm ischemia time was shorter for the exophytic group (median 16 vs. 21 vs. 22 min; p < 0.001). Postoperative complications were more frequent in patients with endophytic tumor (24.8% vs. 19.5% vs. 14.8%; p < 0.001). Six (4.5%) patients had positive surgical margins, there was no difference between groups. Trifecta was achieved in 44 patients in endophytic group (45.4 vs. 68.8 and 50.9%, p < 0.001). Multivariable analysis for trifecta revealed that clinical tumor size (odds ratio: 0.667, 95% confidence interval: 0.56-0.79, p < 0.001) was only significant predictor for trifecta achievement.

CONCLUSIONS

Our findings confirm that RAPN in case of completely endophytic renal masses can be performed with acceptable outcomes in centers with significant robotic expertise.

X-Capsular Incision for Tumor Enucleation (X-CITE)-Technique: A Method to Maximize Renal Parenchymal Preservation for Completely Endophytic Renal Tumors

OBJECTIVE

To describe the X-Capsular Incision for Tumor Enucleation (X-CITE) technique to resect endophytic renal tumors while preserving the overlying renal parenchyma.

SUBJECTS AND METHODS

We reviewed 1-year outcomes of 12 consecutive patients with a history of bilateral or multifocal renal tumors who presented to our institution with completely endophytic renal masse(s) between August 2017 and August 2018. Endophytic tumors were resected by making an X-shaped incision in the renal capsule and developing parenchymal flaps overlying the tumor pseudocapsule. Following tumor enucleation, the overlying parenchymal flaps were reapproximated.

RESULTS

Median follow up was 19.9 months (range 10.6-14.9). Most patients also had additional exophytic tumors with a median of 5 renal tumors removed per operation with a median largest renal tumor size of 3.2 cm. No intraoperative or postoperative complications occurred. There was no decline in renal function after surgery when comparing median pre- and 12-month postoperative eGFR (94.5 vs 91.5, P= 0.18).). Postoperative nuclear mercaptoacetyltriglycine (MAG-3) renal scans demonstrated equal differential kidney function after surgery. Limitations include short-term follow-up and referral bias at center specializing in multi-focal kidney surgery.

CONCLUSION

The X-Capsular Incision for Tumor Enucleation technique is feasible, safe and effective with minimal collateral damage in the treatment of completely endophytic renal masses. Further investigation should identify which patients may benefit from this procedure and explore intermediate and long-term outcomes.

The BMI Paradox and Robotic Assisted Partial Nephrectomy

Introduction: Partial nephrectomy (PN), has become the gold standard for the surgical management of small renal masses, due to excellent oncologic control with concomitant preservation of nephron units. However, data regarding the association of obesity with perioperative outcomes following PN are mixed. Therefore, the association between obesity (using BMI) and post-operative complications (POC) rate following Robotic assisted laparoscopic PN (RPNx) was tested.

Methods: Two hundred and fifty-one adult patients who underwent RPNx from 1/2011 to 5/2017 at a single institution, with at least 90 days follow-up were identified and included. No patients were excluded. Electronic medical records were reviewed to record all POC within 90 days of surgery. A piecewise generalized linear model for binary outcomes (logistic) was used to model the proportion of subjects with POC by their BMI. The slope of the line is adjusted to a BMI of 30 Kg/m².

Results: BMI is significantly associated with POC rate. POC rate decreased with increasing BMI below the inflection point of 30 Kg/m² (0.848[0.756, 0.952]) (OR [95% CI], p = 0.005). POC rate was found to increase with increasing BMI above the BMI inflection of 30 Kg/m² (1.102 [1.027, 1.182], p = 0.0071).

Conclusions: In this cohort study, BMI showed an association with PC. It may be important to take BMI into account in surgical and clinical management considerations of RPNx, since higher rates of POC are associated with patients who are underweight, morbidly obese, and even with normal BMI. Further research is required on larger cohorts of RPNx patients to provide better description of this phenomenon and elucidate the role of BMI in development of POC.

Novel Use of Folate-Targeted Intraoperative Fluorescence, OTL38, in Robot-Assisted Laparoscopic Partial Nephrectomy: Report of the First Three Cases

Partial nephrectomy is now the preferred surgical option for small renal tumors because it allows nephron preservation without compromising oncologic clearance. Its outcomes depend on the surgeon's ability to continuously identify the edges of the tumor during resection, thus leaving an adequate margin around the tumor without excessive removal of normal parenchyma, as well as keeping a short ischemic time. Folate receptors are highly abundant in the normal kidney, and there is a difference in folate receptor expression between malignant and normal renal tissues. Thus, the use of fluorescent agents that target folate receptors should result in differential fluorescence between the tumor and surrounding parenchyma during partial nephrectomy, which, in turn, helps tumor demarcation for identification and resection. A phase 2 study on the novel use of OTL38 in robot-assisted laparoscopic partial nephrectomy is currently in progress in our institution. The outcomes of the first three cases have shown the possible advantages of OTL38 in intraoperative tumor identification before resection and recognition of residual disease in the surrounding parenchyma after resection. The tumors typically appeared dark while the surrounding parenchyma showed brighter fluorescence. Immediately after tumor resection, the margins of all the specimens appeared to have a uniformly bright fluorescence, suggestive of an intact margin of normal renal parenchyma along the plane of excision. The pattern of intraoperative fluorescence correlates well with immunohistochemistry. No OTL38-related adverse effects have been seen among these three patients. We present the outcomes of these three cases, illustrated with intraoperative and immunohistochemistry images.

Comparison of robot-assisted and open partial nephrectomy for completely endophytic renal tumours: a single centre experience

OBJECTIVE

To compare outcomes between robot-assisted partial nephrectomy (RAPN) and open PN (OPN) for completely endophytic renal tumours.

PATIENTS AND METHODS

We retrospectively reviewed 1 230 consecutive cases, consisting of 823 RAPNs and 407 OPNs, performed for renal mass at a single academic tertiary centre between 2011 and 2016. Of these, data on 87 RAPN and 56 OPN cases for completely endophytic renal tumours were analysed. Patient and tumour characteristics, operative, postoperative, functional, and oncological outcomes were compared between groups.

RESULTS

Apart from a higher prevalence of solitary kidney among OPN cases (RAPN, 5.7% vs OPN, 21.4%; P = 0.005), demographic characteristics were similar between the groups. There were no statistically significant differences in tumour size (P = 0.07), tumour stage (P = 0.3), margin status (P = 0.48), malignant tumour subtypes (P = 0.51), and grades (P = 0.61) between the groups. Also, there were no statistically significant differences among the groups for warm ischaemia time (P = 0.15), cold ischaemia time (P = 0.28), and intraoperative (P = 0.75) or postoperative (Clavien-Dindo Grade I-V, P = 0.08; Clavien-Dindo Grade III-V, P = 0.85) complication rates. The patients in the RAPN group had a shorter length of stay (P < 0.001), less estimated blood loss (P < 0.001), and lower intraoperative transfusion rates (0% vs 7.1%, P = 0.02). No local recurrences occurred during a median (interquartile range) follow-up of 15.2 (7-27.2) and 18.1 (8.2-30.9) months in the RAPN and OPN groups, respectively. There was no difference in estimated glomerular filtration rate preservation rates between groups for the early (P = 0.26) and latest (P = 0.22) functional follow-up.

CONCLUSION

For completely endophytic renal tumours, both OPN and RAPN have excellent outcomes when performed by experienced surgeons at a high-volume centre. For skilled robotic surgeons, RAPN is a safe and effective alternative to OPN with the advantages of shorter length of stay and less blood loss.

Review of robot-assisted partial nephrectomy in modern practice

Partial nephrectomy (PN) is currently the standard treatment for T1 renal tumors. Minimally invasive PN offers decreased blood loss, shorter length of stay, rapid convalescence, and improved cosmesis. Due to the challenges inherent in laparoscopic partial nephrectomy, its dissemination has been stifled. Robot-assisted partial nephrectomy (RAPN) offers an intuitive platform to perform minimally invasive PN. It is one of the fastest growing robotic procedures among all surgical subspecialties. RAPN continues to improve upon the oncological and functional outcomes of renal tumor extirpative therapy. Herein, we describe the surgical technique, outcomes, and complications of RAPN.