Standardized reporting of resection technique during nephron-sparing surgery: the surface-intermediate-base margin score

The evolving management of small renal masses

Small renal masses (SRMs) are a heterogeneous group of tumours with varying metastatic potential. The increasing use and improving quality of abdominal imaging have led to increasingly early diagnosis of incidental SRMs that are asymptomatic and organ confined. Despite improvements in imaging and the growing use of renal mass biopsy, diagnosis of malignancy before treatment remains challenging. Management of SRMs has shifted away from radical nephrectomy, with active surveillance and nephron-sparing surgery taking over as the primary modalities of treatment. The optimal treatment strategy for SRMs continues to evolve as factors affecting short-term and long-term outcomes in this patient cohort are elucidated through studies from prospective data registries. Evidence from rapidly evolving research in biomarkers, imaging modalities, and machine learning shows promise in improving understanding of the biology and management of this patient cohort.

Molecular mechanism of formation and destruction of a pseudo‑capsule in clear cell renal cell carcinoma

The process and molecular mechanisms underlying the formation and destruction of a pseudo-capsule (PC) in clear cell renal cell carcinoma (ccRCC) are poorly understood. In the present study, the PCs of surgical specimens from primary tumors and metastatic lesions in 169 patients with ccRCC, and carcinogen-induced ccRCC rat models were semi-quantified using the invasion of PC (i-Cap) score system. This was based on the relationship among the tumor, PC and adjacent normal tissue (NT) as follows: i-Cap 0, tumor has no PC and does not invade NT; i-Cap 1, tumor has a complete PC and does not invade into the PC; i-Cap 2, tumor with focal absences in the PC, which partially invades the PC but not completely through the PC; i-Cap 3, tumor crosses the PC and invades the NT; i-Cap 4, tumor directly invades the NT without a PC. The study suggested that PC formation was not observed without physical compression, and also revealed that tumor invasion into the PC was a prognostic factor for postoperative oncological outcomes. Higher i-Cap, Fuhrman grade and tumor size were independent poor prognostic factors for postoperative disease-free survival. mRNA expression arrays generated from carcinogen-induced ccRCC rat models were used to explore genes potentially associated with the formation and destruction of a PC. Subsequently, human ccRCC specimens were validated for four genes identified via expression array; the results revealed that collagen type 4A2, matrix metalloproteinase-7 and l-selectin were upregulated alongside the progression of i-Cap score. Conversely, endoglin was downregulated. In conclusion, the present study provides insights into the formation and destruction of a PC, and the results may aid the treatment and management of patients with ccRCC.

Comparison of Perioperative, Functional, and Oncologic Outcomes of Open vs. Robot-Assisted Off-Clamp Partial Nephrectomy: A Propensity Scored Match Analysis

Off-clamp partial nephrectomy represents one of the latest developments in nephron-sparing surgery, with the goal of preserving renal function and reducing ischemia time. The aim of this study was to evaluate and compare the functional, oncologic, and perioperative outcomes between off-clamp robot-assisted partial nephrectomy (off-C RAPN) and off-clamp open partial nephrectomy (off-C OPN) through a propensity score-matched (PSM) analysis. A 1:1 PSM analysis was used to balance variables potentially affecting postoperative outcomes. To report surgical quality, 1 year trifecta was used. Univariable Cox regression analysis was performed to identify predictors of trifecta achievement. The Kaplan-Meier method was used to compare cancer-specific survival (CSS), overall survival (OS), disease-free survival (DFS), and metastasis-free survival (MFS) probabilities between groups. Overall, 542 patients were included. After PSM analysis, two homogeneous cohorts of 147 patients were obtained. The off-C RAPN cohort experienced shorter length of stay (LoS) (3.4 days vs. 5.4 days; p < 0.001), increased likelihoods of achieving 1 year trifecta (89.8% vs. 80.3%; p = 0.03), lower postoperative Clavien-Dindo ≤ 2 complications (1.3% vs. 18.3%, p < 0.001), and lower postoperative transfusion rates (3.4% vs. 12.2%, p = 0.008). At univariable analysis, the surgical approach (off-C RAPN vs. off-C OPN, OR 2.22, 95% CI 1.09-4.46, p = 0.02) was the only predictor of 1 year trifecta achievement. At Kaplan-Meier analysis, no differences were observed between the two groups in terms of OS (log-rank p = 0.451), CSS (log-rank p = 0.476), DFS (log-rank p = 0.678), and MFS (log-rank p = 0.226). Comparing RAPN and OPN in a purely off-clamp scenario, the minimally invasive approach proved to be a feasible and safe surgical approach, with a significantly lower LoS and minor rate of postoperative complications and transfusions as a result of improved surgical quality expressed by higher 1 year trifecta achievement.

Robot-assisted Simple Enucleation Versus Standard Robot-assisted Partial Nephrectomy for Low- or Intermediate-complexity, Clinical T1 Renal Tumors: A Randomized Controlled Noninferiority Trial

BACKGROUND

Although partial nephrectomy has become the gold standard for T1 renal tumors whenever technically feasible, simple enucleation has shown superior results. To the best of our knowledge, no randomized controlled trials comparing these two surgical approaches have been published.

OBJECTIVE

To compare the surgical margin status for robot-assisted simple enucleation (RASE) and standard robot-assisted partial nephrectomy (sRAPN) for clinical T1 renal tumors.

DESIGN, SETTING, AND PARTICIPANTS

This is a prospective, randomized, controlled, noninferiority trial. A total of 380 patients aged 18-80 yr with newly diagnosed, sporadic, unilateral clinical T1 renal tumors (RENAL score <10) were enrolled and randomized to RASE or sRAPN. The primary endpoint was the positive surgical margin (PSM) rate, with a noninferiority margin of 7.5% set. The study was registered on ClinicalTrials.gov (NCT03624673).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We defined noninferiority for RASE versus standard RAPN as an upper 95% confidence interval (CI) bound of <7.5% for the difference in the proportion of patients with a PSM.

RESULTS AND LIMITATIONS

A cohort of 380 patients was enrolled and randomly assigned to RASE (n = 190) or sRAPN (n = 190). On intention-to-treat analysis for patients with malignant tumors, 2.3% of patients in the RASE group and 3.0% in the sRAPN group had a PSM. The RASE group showed noninferiority to the sRAPN group within a 7.5% margin (difference -0.7%, 95% CI -4.0% to 2.7%). Per-protocol analysis also demonstrated noninferiority of RASE. The RASE group had a shorter median operative time (145 vs 155 min; p = 0.018) and a lower rate of tumor bed suturing (8.9% vs 43%; p < 0.001) in comparison to the sRAPN group. Estimated blood loss was considerably lower in the sRAPN group than in the RASE group (p = 0.046). The rate of recurrence did not differ between the groups (p > 0.9).

CONCLUSIONS

RASE for the management of low- to intermediate-complexity tumors is noninferior to sRAPN in terms of the PSM rate. Long-term follow-up is needed to draw conclusions regarding oncological outcomes.

PATIENT SUMMARY

We carried out a trial to compare simple tumor enucleation versus partial nephrectomy for renal tumors. The outcome we assessed was the proportion of patients with a positive surgical margin. Our results show that simple tumor enucleation is not inferior to partial nephrectomy for this outcome. Longer follow-up is needed to assess other cancer control outcomes.

Redo Partial Nephrectomy for Local Recurrence After Previous Nephron-sparing Surgery. Surgical Insights and Oncologic Results from a High-volume Robotic Center

Background

The role of redo partial nephrectomy (PN) for recurrent renal cell carcinoma (RCC) is still overlooked.

Objective

To report our experience of salvage PN for local recurrence after previous nephron-sparing surgery (NSS).

Design setting and participants

We prospectively gathered data from patients treated with robotic redo PN for locally recurrent RCC after previous NSS from January 2017 to January 2023. The type of surgical resection technique was assigned to the pathologic specimen according to the surface-intermediate-base (SIB) score.

Surgical procedure

Redo PN was performed by using the Si Da Vinci robotic platform.

Measurements

Operative time, warm ischemia time, and intra- and postoperative complications were recorded. The severity of postoperative complications and tumor stage were evaluated.

Results and limitations

Overall, 26 patients entered the study. The median clinical diameter was 3.5 (interquartile range [IQR] 2.2-4.9) cm and the median Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score was 8 (IQR 7-9). In 14 (53.8%) cases, recurrence was at the level of previous tumor resection bed. The median operative time was 177 (IQR 148-200) min, and hilar clamping was performed in 14 (53.8%) cases with a median warm ischemia time of 16 (14.5-22) min. Pure enucleation (SIB score 0-1), hybrid enucleation (SIB score 2), and pure enucleoresection (SIB score 3) were recorded in 13 (50%), eight (30.8%), and five (19.2%) cases, respectively. The totality of recurrent RCC far from previous tumor resection bed received a SIB score of 0-1, while in 57.1% and 35.8% of recurrent RCC on previous tumor resection a hybrid enucleation and a pure enucleoresection were performed, respectively. At a median follow-up of 37 (IQR 16-45) mo, five (19%) patients experienced disease recurrence, being local and systemic in three (11.5%) and two (7.7%) patients, respectively.

Conclusions

Our study highlights the feasibility and safety of redo PN for the treatment of locally recurrent RCCs after NSS, either on previous tumor resection bed or elsewhere in the kidney.

Patient summary

Robotic redo partial nephrectomy is a challenging procedure. The surgeon needs to tailor the surgical strategy and tumor resection technique case by case, given the heterogeneity of clinical scenarios and the need to achieve maximal functional preservation while ensuring oncologic efficacy.

Impact of renal sinus protrusions on achieving trifecta in robot-assisted partial nephrectomy

Objective

The objective of this work is to assess the relationship between the morphological characteristics of a central tumour and the perioperative outcomes of robot-assisted partial nephrectomy (RAPN).

Subjects and Methods

We retrospectively analysed the data from 186 patients with central tumours involving the renal sinus, who underwent RAPN in a single-centre study between February 2015 and June 2022. All cases were assigned a RENAL nephrometry score based on preoperative images. The shape of the protruding portion of the tumour was classified into four types: 'flat', 'spherical', 'single-hump', and 'complex-hump', and was independently assessed by two readers. The trifecta is defined as the warm ischemia time within 25 min, negative surgical margins, and no major postoperative complications. Univariate and multivariate analyses were performed to identify the factors associated with the failing trifecta.

Results

Trifecta was achieved in 113 cases (60.8%), and the achievement rate in flat, spherical, single-hump, and complex-hump types was 83.3%, 74.5%, 64.3%, and 21.3%, respectively. Prolonged warm ischemia time was the primary cause of the failure to achieve the trifecta. The rate of positive surgical margins and upstage to pathological T3a was greater for complex humps while the rate of major complications and postoperative GFR preservation did not differ between shapes. On multivariate analysis for failing trifecta achievement, the complex-hump protrusion was found to be an independent positive predictor (odds ratio: 15.8; p < 0.001), whereas the height and width of protrusion were not significantly related.

Conclusions

The degree of difficulty varied among central tumours, and it was not possible to precisely measure it with existing scoring systems. Complex-hump protrusions strongly correlate with failure to achieve the trifecta. Preoperative assessment of the morphology of protrusion is useful for predicting outcomes.

Resection Techniques During Robotic Partial Nephrectomy: A Systematic Review

Context

The resection technique used to excise tumor during robotic partial nephrectomy (RPN) is of paramount importance in achieving optimal clinical outcomes.

Objective

To provide an overview of the different resection techniques used during RPN, and a pooled analysis of comparative studies.

Evidence acquisition

The systematic review was conducted according to established principles (PROSPERO: CRD42022371640) on November 7, 2022. A population (P: adult patients undergoing RPN), intervention (I: enucleation), comparator (C: enucleoresection or wedge resection), outcome (O: outcome measurements of interest), and study design (S) framework was prespecified to assess study eligibility. Studies reporting a detailed description of resection techniques and/or evaluating the impact of resection technique on outcomes of surgery were included.

Evidence synthesis

Resection techniques used during RPN can be broadly classified as resection (non-anatomic) or enucleation (anatomic). A standardized definition for these is lacking. Out of 20 studies retrieved, nine compared "standard" resection versus enucleation. A pooled analysis did not reveal significant differences in terms of operative time, ischemia time, blood loss, transfusions, or positive margins. Significant differences favoring enucleation were found for clamping management (odds ratio [OR] for renal artery clamping 3.51, 95% confidence interval [CI] 1.13-10.88; p = 0.03), overall complications (OR for occurrence 0.55, 95% CI 0.34-0.87; p = 0.01) major complications (OR for occurrence 0.39, 95% CI 0.19-0.79; p = 0.009), length of stay (weighted mean difference [WMD] -0.72 d, 95% CI -0.99 to -0.45; p < 0.001), and decrease in estimated glomerular filtration rate (WMD -2.64 ml/min, 95% CI -5.15 to -0.12; p = 0.04).

Conclusions

There is heterogeneity in the reporting of resection techniques used during RPN. The urological community must improve the quality of reporting and research produced accordingly. Positive margins are not specifically related to the resection technique. Focusing on studies comparing standard resection versus enucleation, advantages with tumor enucleation in terms of avoidance of artery clamping, overall/major complications, length of stay, and renal function were found. These data should be considered when planning the RPN resection strategy.

Patient summary

We reviewed studies on robotic surgery for partial kidney removal using different techniques to cut away the kidney tumor. We found that a technique called "enucleation" was associated with similar cancer control outcomes in comparison to the standard technique and had fewer complications, better kidney function after surgery, and a shorter hospital stay.

The IRON Study: Investigation of Robot-assisted Versus Open Nephron-sparing Surgery

Background

Current literature does not provide large-scale data regarding clinical outcomes of robot-assisted (RAPN) versus open (OPN) partial nephrectomy. Moreover, data assessing predictors of long-term oncologic outcomes after RAPN are scarce.

Objective

To compare perioperative, functional, and oncologic outcomes of RAPN versus OPN, and to investigate the predictors of oncologic outcomes after RAPN.

Design setting and participants

This study included 3467 patients treated with OPN (n = 1063) or RAPN (n = 2404) for a single cT_1-2N₀M₀ renal mass from 2004 to 2018 at nine high-volume European, North American, and Asian institutions.

Outcome measurements and statistical analysis

The study outcomes were short-term postoperative, functional, and oncologic outcomes. Regression models investigated the effect of surgical approach (open vs Robot assisted) on study outcomes, and interaction tests were used for subgroup analyses. Propensity score matching for demographic and tumor characteristics was used in sensitivity analyses. Multivariable Cox-regression analyses identified predictors of oncologic outcomes after RAPN.

Results and limitations

Baseline characteristics were similar between patients receiving RAPN and OPN, with only few differences. After adjusting for confounding, RAPN was associated with lower odds of intraoperative (odds ratio [OR]: 0.39, 95% confidence interval [CI]: 0.22, 0.68) and Clavien-Dindo ≥2 postoperative (OR: 0.29, 95% CI: 0.16, 0.50) complications (both p < 0.05). This association was not affected by comorbidities, tumor dimension, PADUA score, or preoperative renal function (all p > 0.05 on interaction tests). On multivariable analyses, we found no differences between the two techniques with respect to functional and oncologic outcomes (all p > 0.05). Overall, there were 63 and 92 local recurrences and systemic progressions, respectively, with a median follow-up after surgery of 32 mo (interquartile range: 18, 60). Among patients receiving RAPN, we assessed predictors of local recurrence and systemic progression with discrimination accuracy (ie, C-index) that ranged from 0.73 to 0.81.

Conclusions

While cancer control and long-term renal function did not differ between RAPN and OPN, we found that the intra- and postoperative morbidity-especially in terms of complications-was lower after RAPN than after OPN. Our predictive models allow surgeons to estimate the risk of adverse oncologic outcomes after RAPN, with relevant implications for preoperative counseling and follow-up after surgery.

Patient summary

In this comparative study on robotic versus open partial nephrectomy, functional and oncologic outcomes were similar between the two techniques, with lower morbidity-especially in terms of complications-for robot-assisted surgery. The assessment of prognosticators for patients receiving robot-assisted partial nephrectomy may help in preoperative counseling and provides relevant data to tailor postoperative follow-up.

Randomized Clinical Trial Comparing On-clamp Versus Off-clamp Laparoscopic Partial Nephrectomy for Small Renal Masses (CLOCK II Laparoscopic Study): A Intention-to-treat Analysis of Perioperative Outcomes

Background

Recent randomized trials (RCTs) in the field of robotic partial nephrectomy (PN) showed no significant differences in perioperative outcomes between the off- and on-clamp approaches.

Objective

To compare the perioperative outcomes of on- versus off-clamp pure laparoscopic PN (LPN).

Design setting and participants

A multi-institutional analysis of the on- versus off-clamp approach during LPN in the setting of an RCT (CLOCK II trial; ClinicalTrials.gov NCT02287987) was performed.

Intervention

Off- versus on-clamp LPN.

Outcome measurements and statistical analysis

Baseline patient and tumor variables, and peri- and postoperative data were collected. Randomized allocation with a 1:1 ratio was assigned. Surgical strategy for managing the renal pedicle was dictated by the study protocol. In the off-clamp arm, the renal artery had to remain unclamped for the duration of the whole procedure. Reporting the intention-to-treat analysis is the purpose of the study.

Results and limitations

The study recruited 249 patients. Of them, 123 and 126 were randomized and allocated into the on- and off-clamp treatment groups, respectively. Treatment groups were comparable at baseline after randomization with respect to patients' demographics, comorbidities, renal function, and tumor size and complexity. A univariable analysis found no differences in the perioperative outcomes between the groups, including median (interquartile range) estimated blood loss (150 [100-200] vs 150 [100-250] ml, p = 0.2), grade ≥2 complication rate as classified according to the Clavien-Dindo system (5.7% vs 4.8%, p = 0.6), and positive surgical margin rate (8.2% vs 3.5% for the on- vs off-clamp group, p = 0.1). No differences were found in terms of the 1st (81.3 [66.7-94.3] vs 85.3 [71.0-97.7] ml/min, p = 0.2) and 5th postoperative days estimated glomerular filtration rate (83.3 [70.5-93.7] vs 83.4 [68.6-139.3] ml/min, p = 0.2). A multivariable analysis found each +1 increase in RENAL score corresponded to an increase in the protection from the occurrence of complications (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.54-0.97, p = 0.034), while each +1 cm increase in tumor size corresponded to an increase in the risk of blood transfusion (OR 1.39, 95% CI 1.14-1.70, p = 0.001).

Conclusions

In the setting of an RCT, no differences were found in the perioperative and early functional outcomes between on- and off-clamp LPN.

Patient summary

In this study, we investigated, by means of a randomized trial, whether avoiding the clamping of renal artery during laparoscopic resection of renal mass is able to translate into benefits. We found no differences in terms of safety, efficacy, and renal function from the standard approach, which includes arterial clamping.

Purely Off-Clamp Partial Nephrectomy: Robotic Approach Better than Open Using a Pentafecta Outcome with Propensity Score Matching

Partial nephrectomy (PN) is the gold standard treatment for localized renal masses. Robot-assisted PN (RAPN) has overcome laparoscopy’s technical limitations, greatly expanding the indications of minimally invasive PN, which is dominated by renal artery clamping in almost all published series. We compared off-clamp RAPN (OFFC-RAPN) with the open approach (OFFC-OPN) using propensity score (PS) matching. A favourable pentafecta outcome was defined as a combination of no positive surgical margins (PSM), no complications of Clavien−Dindo (CD) grade ≥ 3, post-operative eGFR loss <10%, length of hospital stay (LOS) ≤ 5 days and estimated blood loss (EBL) < 200 mL. A total of 340 consecutive patients were included. The PS-matched cohort included 142 patients: 71 matched pairs well-balanced for all covariates. The OFFC-RAPN group showed significantly shorter operative time (149.8 vs. 173.9 min, p = 0.003), lower EBL (182.1 vs. 329.3 mL, p = 0.001), and shorter LOS (5.8 vs. 6.9 days, p = 0.02), with a higher proportion of patients with LOS ≤ 5 days (57.7% vs. 23.9%, p < 0.001). No significant differences were found for PSM rate (2.8% vs. 8.4%, p = 0.27), CD > 2 complication rate (4.2% vs. 2.8%, p = 1.00) and mean ± SD eGFR change (−0.06 ± 0.3 vs. −0.8 ± 0.3, p = 0.5). Pentafecta was achieved in 56.3% and 21.1% in the OFFC-RAPN and OFFC-OPN series, respectively (p < 0.0001). On multivariable analysis, surgical approach and BMI proved to be independent predictors of achieving pentafecta. After adjusting for potential treatment selection bias, OFFC-RAPN outperformed OFFC-OPN for important peri-operative outcomes, without compromising oncological and functional safety.

Surgical and functional outcomes of robot-assisted versus laparoscopic partial nephrectomy with cortical renorrhaphy omission

To evaluate the surgical and functional outcomes between robot-assisted (CRO-RAPN) vs. laparoscopic (CRO-LPN) methods of cortical-renorrhaphy-omitting partial nephrectomy. Between July 2012 and June 2020, patients with localized clinical T1-2 renal masses who underwent CRO-RAPN or CRO-LPN were reviewed. The outcomes of the two groups were compared using propensity-score matching. Trifecta was defined as negative surgical margin, warm ischemic time < 25 min, and absence of complications of Clavien-Dindo grade III or more until three months postoperatively. The preservation rate of the estimated glomerular filtration rate (eGFR) was evaluated at six months postoperatively. Among 291 patients (CRO-RAPN, n = 210; CRO-LPN, n = 81) included in the study, 150 matched pairs of patients were analyzed. Compared to the CRO-LPN group, the CRO-RAPN group was associated with shorter warm ischemic time (13 min vs. 20 min, P < 0.001), shorter total operation time (162 min vs. 212 min, P < 0.001), less estimated blood loss (40 mL vs. 119 mL, P = 0.002), lower incidence of overall complications (3% vs. 16%, P = 0.001), higher preservation rate of eGFR at six months postoperatively (93% vs. 89%, P = 0.003), and higher trifecta achievement rate (84% vs. 64%, P = 0.004). CRO-RAPN contributed to shorter warm ischemic time, less blood loss, fewer complications, and higher preservation of renal function, all of which allowed this technique to achieve a higher rate of trifecta compared to CRO-LPN.

Current strategies to diagnose and manage of positive surgical margins and local recurrence after partial nephrectomy

Objective

No standard strategy for diagnosis and management of positive surgical margin (PSM) and local recurrence after partial nephrectomy (PN) are reported in literature. This review aims to provide an overview of the current strategies and further perspectives on this patient setting.

Methods

A non-systematic review of the literature was completed. The research included the most updated articles (about the last 10 years).

Results

Techniques for diagnosing PSMs during PN include intraoperative frozen section, imprinting cytology, and other specific tools. No clear evidence is reported about these methods. Regarding PSM management, active surveillance with a combination of imaging and laboratory evaluation is the first option line followed by surgery. Regarding local recurrence management, surgery is the primary curative approach when possible but it may be technically difficult due to anatomy resultant from previous PN. In this scenario, thermal ablation (TA) may have the potential to circumvent these limitations representing a less invasive alternative. Salvage surgery represents a valid option; six studies analyzed the outcomes of nephrectomy on local recurrence after PN with three of these focused on robotic approach. Overall, complication rates of salvage surgery are higher compared to TA but ablation presents a higher recurrence rate up to 25% of cases that can often be managed with repeat ablation.

Conclusion

Controversy still exists surrounding the best strategy for management and diagnosis of patients with PSMs or local recurrence after PN. Active surveillance is likely to be the optimal first-line management option for most patients with PSMs. Ablation and salvage surgery both represent valid options in patients with local recurrence after PN. Conversely, salvage PN and radical nephrectomy have fewer recurrences but are associated with a higher complication rate compared to TA. In this scenario, robotic surgery plays an important role in improving salvage PN and radical nephrectomy outcomes.

Diagnosis and Treatment of Small Renal Masses: Where Do We Stand?

PURPOSE OF REVIEW

To present an overview of the current evidence-based studies covering diagnostic and management of SRM.

RECENT FINDINGS

Renal cell carcinoma (RCC) represents 3% of the cancers. Nowadays, partial nephrectomy (PN) represents gold standard treatment. New nephron-sparing approaches such as active surveillance and ablative therapies have been increasingly used as an alternative to surgical intervention. Due to novel comprehension of RCC and widespread use of imaging techniques, diagnosis at early stage in elderly patients has increased. Treatment decision-making should be based on patient and tumour characteristics. With expanding treatment options, the management of SRMs has become a debate and should be adjusted to patient and tumour characteristics. In a shared decision manner, both active surveillance with possible delayed intervention and focal therapy should be discussed with the patient as an alternative to partial nephrectomy.

Impact of Trifecta definition on rates and predictors of "successful" robotic partial nephrectomy for localized renal masses: results from the Surface-Intermediate-Base Margin Score International Consortium

BACKGROUND

Over the years, five different Trifecta score definitions have been proposed to optimize the framing of "success" in partial nephrectomy (PN) field. However, such classifications rely on different metrics. The aim of the present study was to explore how the success rate of robotic PN, as well as its drivers, vary according to the currently available definitions of Trifecta.

METHODS

Data from consecutive patients with cT1-2N0M0 renal masses treated with robotic PN at 16 referral centers from September 2014 to March 2015 were prospectively collected. Trifecta rate was defined for each of the currently available definitions. Multivariable logistic regression analysis was used to evaluate possible predictors of "Trifecta failure" according to the different adopted formulation.

RESULTS

Overall, 289 patients met the inclusion criteria. Among the definitions, Trifecta rates ranged between 66.4% and 85.9%. Multivariable analysis showed that predictors for "Trifecta failure" were mainly tumor-related (i.e. tumor's nephrometry) for those Trifecta scores relying on WIT as a surrogate metric for postoperative renal function deterioration (definitions 1,2), while mainly surgery-related (i.e. ischemia time and excision strategy) for those including the percentage change in postoperative eGFR as the functional cornerstone of Trifecta (definitions 3-5).

CONCLUSIONS

There was large variability in rates and predictors of "unsuccessful PN" when using different Trifecta scores. Further research is needed to improve the value of the Trifecta metrics, integrating them into routine patient counseling and standardized assessment of surgical quality across institutions.

Predictors of Positive Surgical Margins after Robot-Assisted Partial Nephrectomy for Localized Renal Tumors: Insights from a Large Multicenter International Prospective Observational Project (The Surface-Intermediate-Base Margin Score Consortium)

Background: To explore predictors of positive surgical margins (PSM) after robotic partial nephrectomy (PN) in a large multicenter international observational project, harnessing the Surface-Intermediate-Base (SIB) margin score to report the resection technique after PN in a standardized way. Methods: Data from consecutive patients with cT1-2N0M0 renal masses treated with PN from September 2014 to March 2015 at 16 tertiary referral centers and included in the SIB margin score International Consortium were prospectively collected. For the present study, only patients treated with robotic PN were included. Uni- and multivariable analysis were fitted to explore clinical and surgical predictors of PSMs after PN. Results: Overall, 289 patients were enrolled. Median (IQR) preoperative tumor size was 3.0 (2.3−4.2) cm and median (IQR) PADUA score was 8 (7−9). SIB scores of 0−2 (enucleation), 3−4 (enucleoresection) and 5 (resection) were reported in 53.3%, 27.3% and 19.4% of cases, respectively. A PSM was recorded in 18 (6.2%) patients. PSM rate was 4.5%, 11.4% and 3.6% in case of enucleation, enucleoresection and resection, respectively. Patients with PSMs had tumors with a higher rate of contact with the urinary collecting system (55.6% vs. 27.3%; p < 0.001) and a longer median warm ischemia time (22 vs. 16 min; p = 0.02) compared with patients with negative surgical margins, while no differences emerged between the two groups in terms of other tumor features (i.e., pathological diameter, PADUA score). In multivariable analysis, only enucleoresection (SIB score 3−4) versus enucleation (SIB score 0−2) was found to be an independent predictor of PSM at final pathology (HR: 2.68; 95% CI: 1.25−7.63; p = 0.04), while resection (SIB score 5) was not. Conclusions: In our experience, enucleoresection led to a higher risk of PSMs as compared to enucleation. Further studies are needed to assess the differential impacts of resection technique and surgeon’s experience on margin status after robotic PN.

Comparison of Tumor Enucleation and Standard Partial Nephrectomy According to Trifecta Outcomes: A Multicenter Study by the Turkish Academy of Urology, Uro-Oncology Working Group

INTRODUCTION

We aimed to evaluate the impact of the resection technique (tumor enucleation (TE) or standard partial nephrectomy (SPN)) on trifecta outcomes in patients having undergone partial nephrectomy (PN).

MATERIALS AND METHODS

We retrospectively analyzed the clinical and pathologic parameters in patients with localized renal cell carcinoma (pT1-2N0M0) who had undergone PN between January 2001-December 2018 at one of 15 different tertiary referral centers. Multivariable logistic regression analysis was applied to investigate independent predictors of trifecta failure, decreased postoperative renal functions (decreased estimated glomerular filtration rate (eGFR) > 10%), perioperative complications (Clavien-Dindo > 1), and positive surgical margins.

RESULTS

A total of 1070 patients with a mean age 56.11 ± 11.88 years were included in our study. PN was performed with TE in 848 (79.25%) and SPN in 222 (20.75%) patients. Trifecta failure rate was 56.2% for TE and 64.4% for SPN (p = 0.028). On multivariable analysis, TE was associated with less trifecta failure (p = 0.025) and eGFR decrease >10% rates (p = 0.024). On the other hand, there was no statistically significant difference between TE and SPN according to positive surgical margins (p = 0.450) and complication > Clavien-Dindo grade 1 (p = 0.888) rates. The only independent predictive factor for complications > Clavien-Dindo 1 was the Charlson comorbidity index (CCI) (p = 0.001).

CONCLUSION

TE is associated with less trifecta failure than SPN. This result is mainly due to better preservation of renal function with TE.

Impact of surgical approach and resection technique on the risk of Trifecta Failure after partial nephrectomy for highly complex renal masses

INTRODUCTION

We aimed to compare the outcomes of open vs robotic partial nephrectomy (PN), focusing on predictors of Trifecta failure in patients with highly complex renal masses.

PATIENTS AND METHODS

We queried the prospectively collected database from the SIB International Consortium, including 507 consecutive patients with cT1-2N0M0 renal masses treated at 16 high-volume referral centres, to select those with highly complex (PADUA score ≥10) tumors undergoing PN. RT was classified as enucleation, enucleoresection or resection according to the SIB score. Trifecta was defined as achievement of negative surgical margins, no acute kidney injury and no Clavien-Dindo grade ≥2 postoperative surgical complications. Multivariable logistic regression analysis was used to assess independent predictors of Trifecta failure.

RESULTS

113 patients were included. Patients undergoing open PN (n = 47, 41.6%) and robotic PN (n = 66, 58.4%) were comparable in baseline characteristics. RT was classified as enucleation, enucleoresection and resection in 46.9%, 34.0% and 19.1% of open PN, and in 50.0%, 40.9% and 9.1% of robotic PN (p = 0.28). Trifecta was achieved in significantly more patients after robotic PN (69.7% vs. 42.6%, p = 0.004). On multivariable analysis, surgical approach (open vs robotic, OR: 2.62; 95%CI: 1.11-6.15, p = 0.027) and tumor complexity (OR for each additional unit of the PADUA score: 2.27; 95%CI: 1.27-4.06, p = 0.006) were significant predictors of Trifecta failure, while RT was not. The study is limited by lack of randomization; as such, selection bias and confounding cannot be entirely ruled out.

CONCLUSIONS

Tumor complexity and surgical approach were independent predictors of Trifecta failure after PN for highly complex renal masses.

Robotic-Assisted Partial Nephrectomy: Techniques to Improve Clinical Outcomes

PURPOSE OF REVIEW

To summarize current options available for robot-assisted partial nephrectomy RECENT FINDINGS: Partial nephrectomy (PN) is a standard treatment option for management of cT1 renal masses. It may be carried out by multiple approaches. Robot-assisted (RA) PN is one such option. The goal of treatment is both correct oncological (negative surgical margins) and functional (preservation of sufficient amount of renal parenchyma of the operated kidney) outcome. Appropriate outcomes depend on multiple factors. There are many, but among others tumor characteristics (size, location, i.e., tumor complexity), patient baseline renal function, patient comorbidities, and performance status etc. Based on all these, the surgeon adapts the intervention for each mass/patient by preoperative planning, absence/use/duration of warm or cold ischemia, perioperative imaging, resection technique adapted to tumor location and depth of invasion, use of hemostatics, type and degree of renal parenchymal closure and others details. Nephroprotective agents have not shown efficacy so far. It should not be forgotten that surgeon's experience plays a key role in the achievement of good results. Although multiple factors have a role in the RA partial nephrectomy, surgeon experience and adaptation of technique of intervention have the crucial role in the achievement of both functional and oncological results.

Limited impact of warm ischemic threshold for partial nephrectomy in the robotic surgery era: A propensity score matching study

OBJECTIVES

To evaluate the association between extended (≥30 min) warm ischemic time and renal function in patients undergoing robot-assisted partial nephrectomy.

METHODS

This multi-institutional study retrospectively recruited 1131 patients who underwent robot-assisted partial nephrectomy. Patients were classified into shorter (<30 min; n = 1038) and longer (≥30 min; n = 92) groups based on the ischemic time required, and 1:2 propensity score matching was used to minimize selection bias. The perioperative outcomes, including acute kidney injury and trifecta attainment, and mid/long-term renal function were assessed before and after matching.

RESULTS

Patients in the longer group had tumors with a significantly larger diameter and RENAL nephrometry score. The decline in the nadir of the estimated glomerular filtration rate was significantly greater in the longer than the shorter group in the unmatched and matched cohorts (-16.2 vs -5.5%, P < 0.001; 15.5 vs -9.5%, P = 0.003, respectively). A higher incidence of acute kidney injury (9.8 vs 2.6%, P = 0.002) was observed in the longer group before matching, whereas the difference was comparable after matching. Before matching, the decline in estimated glomerular filtration rate at 6 months postoperatively was greater (-8.2 vs -5.1%, P = 0.005) and trifecta attainment was lower (50.0 vs 63.5%, P < 0.001) in the longer group. However, the differences were comparable for both the parameters between the groups in the matched cohort.

CONCLUSIONS

While extended warm ischemia during robot-assisted partial nephrectomy can be demanded in case of large and complex tumors, its impact on postoperative renal function is limited.

Evaluation of Peri-operative Outcomes Associated With Resident Involvement on Tumor Resection and Renorrhaphy During Robotic-assisted Partial Nephrectomy

OBJECTIVE

To evaluate perioperative outcomes of resident trainee involvement in tumor resection and renorrhaphy during robotic assisted partial nephrectomy (RAPN).

MATERIALS AND METHODS

We analyzed 500 consecutive RAPN in a single surgeon prospectively maintained database. Cases with resident performed tumor resection and renorrhaphy (N = 71) were case matched on R.E.N.A.L. score and RAPN year using a greedy matching algorithm. Perioperative variables were compared to attending cases.

RESULTS

There were no statistically significant differences in high grade postoperative complications (resident: 3% vs attending: 6%, P = .68), positive margins (resident: 1% vs attending: 3%, P = .31), length of stay (resident: 2.0 vs attending: 2.0 days, P = .73), and 30 day readmission (resident: 7% vs attending: 11%, P = .56). However, residents had a statistically significant longer warm ischemia time (median 21 vs 15 minutes, P <.001), thus less likely to achieve trifecta (66% vs 85%, P = .02). Resident involvement had longer median operative time (197 vs 184 minutes, P = .03). No statistically significant difference in functional volume loss (P = .12) or surface intermediate base margin score (P = .66) between residents and attending was found. No difference in post-operative creatinine change was found at 1 day and 1 month (resident: 0.2 vs attending: 0.1 mg/dL, P = .4 and resident: 0.1 vs attending: 0.1 mg/dL, P = .6, respectively).

CONCLUSION

Supervised resident console involvement in tumor resection and renorrhaphy during RAPN is safe and does not increase rates of complications. Residents have longer median warm ischemia time compared to attending only cases, but this does not appear to impact post-operative renal function.

Developing the surgical technique reporting checklist and standards: a study protocol

BACKGROUND

Standardized and transparent reporting of surgical technique is the cornerstone of effective dissemination, implementation and improvement. However, current reporting of surgical techniques is inadequate. The existing guidelines potentially applied to guide surgical technique reporting are with a minimal highlight of the surgical technique, lack requirements explaining what extent and dimensions need to be described in detail, or are unlikely to extrapolate to a wide range of surgical techniques. This study aims to formulate a rigorous protocol to develop a surgical technique reporting checklist and standards (SUPER) that defines what a clear, comprehensive and detailed surgical technique report should be contained.

METHODS

This protocol is designed following the classic guidance for developing reporting guidelines recommended by the EQUATOR network.

RESULTS

The development team will consist of surgeons (~80%), methodologists, and journal editors. The draft checklist sources will include a scoping review of existing reporting guidelines related to surgical technique, surgical technique articles from 15 top journals published in the last year, and brainstorming by the multidisciplinary development team. The final SUPER checklist will be formed after three rounds of Delphi surveys, one round of face-to-face meeting, and a month-long pilot test. The SUPER checklist will be published as open-access and be used in combination with existing reporting guidelines related to surgical techniques (e.g., IDEAL). This protocol will steer the SUPER checklist's development, allowing us to further elaborate surgical technique reporting for all surgical specialties, and enabling a more favorable experience for surgeons, nurses, medical students, residents, editors, and reviewers.

TRIAL REGISTRATION

This trial is registered at the EQUATOR network on December 18th, 2020. Available at: https://www.equator-network.org/library/reporting-guidelines-under-development/reporting-guidelines-under-development-for-other-study-designs/.

Comparison of surgical outcomes between enucleation and standard resection in robot-assisted partial nephrectomy for completely endophytic renal tumors through a 1:1 propensity score-matched analysis

OBJECTIVE

Robot-assisted laparoscopic partial nephrectomy (RAPN) for completely endophytic renal tumors is challenging because of the tumor complexity. The enucleation technique is an ideal resection method to maximally preserve the renal parenchyma. In the present study, we investigated the surgical outcomes of RAPN for completely endophytic renal tumors and compared them between the enucleation and standard resection techniques.

METHODS

One-hundred-and-forty-four patients who underwent RAPN for completely endophytic tumors were the subjects of this study. The subjects were divided into two groups according to the surface-intermediate-margin (SIB) score: enucleation group (SIB score 0-2) and standard resection group (SIB score 3-5). To minimize selection bias between the two surgical methods, patient variables such as age, sex, body mass index, American Society of Anesthesiologists score, tumor size, RENAL NS, and preoperative renal function were adjusted using 1:1 propensity score matching.

RESULTS

Of the 144 patients, 72 were assigned to the enucleation group and 72 to the standard resection group. After matching, 45 patients were included in each group. The mean tumor size was 26-27 mm and the mean RENAL NS score was 9.0-9.1, after matching. The enucleation group showed significantly better preservation of the estimated glomerular filtration rate (eGFR) in the early postoperative period (-4.9% vs. -16%, p = 0.0005) and at 6-12 months after surgery (-4.9% vs. -9.2%, p = 0.0327) than the standard resection group. In addition, a shorter operation time (140 vs. 167 min, p = 0.0028) was observed in the enucleation group. Other outcomes including estimated blood loss, positive surgical margin rate, incidence rate of complications, and length of hospital stay were not significantly different between the two groups.

CONCLUSION

The enucleation technique showed better surgical outcomes for completely endophytic renal tumors in terms of preservation of renal function and operation time than the standard resection technique.

Case Report: Optimizing Pre- and Intraoperative Planning With Hyperaccuracy Three-Dimensional Virtual Models for a Challenging Case of Robotic Partial Nephrectomy for Two Complex Renal Masses in a Horseshoe Kidney

Objective: To report a case of robot-assisted partial nephrectomy (RAPN) for two highly complex renal tumors in a patient with a Horseshoe kidney (HSK), focusing on the utility of hyperaccuracy three-dimensional (HA3D) virtual models for accurate preoperative and intraoperative planning of the procedure.

Methods: A 74-year-old Caucasian male patient was referred to our Unit for incidental detection of two complex renal masses in the left portion of a HSK. The 50 × 55 mm, larger, predominantly exophytic renal mass was located at the middle-lower pole of the left-sided kidney (PADUA score 9). The 16 × 17 mm, smaller, hilar renal mass was located at the middle-higher pole of the left-sided kidney (PADUA score 9). Contrast-enhanced CT scan images in DICOM format were processed using a dedicated software to achieve a HA3D virtual reconstructions. RAPN was performed by a highly experienced surgeon using the da Vinci Si robotic platform with a three-arm configuration. A selective delayed clamping strategy was adopted for resection of the larger renal mass while a clampless strategy was adopted for the smaller renal mass. An enucleative resection strategy was pursued for both tumors.

Results: The overall operative time was 150 min, with a warm ischemia time of 21 min. No intraoperative or postoperative complications were recorded. Final resection technique according to the SIB score was pure enucleation for both masses. At histopathological analysis, both renal masses were clear cell renal cell carcinoma (ccRCC) (stage pT1bNxMx and pT3aNxMx for the larger and smaller mass, respectively). At a follow-up of 7 months, there was no evidence of local or systemic recurrence.

Conclusions: Surgical management of complex renal masses in patients with HSKs is challenging and decision-making is highly nuanced. To optimize postoperative outcomes, proper surgical experience and careful preoperative planning are key. In this regard, 3D models can play a crucial role to refine patient counseling, surgical decision-making, and pre- and intraoperative planning during RAPN, tailoring surgical strategies and techniques according to the single patient's anatomy.

Greater Renal Function Benefit from Enucleation Technique for More Complex Renal Tumors in Robot-Assisted Partial Nephrectomy

Background: Tumor enucleation technique in robot-assisted partial nephrectomy (RAPN) reportedly contributes to renal function preservation. Which tumors and which part to utilize this technique have not been determined. Patients and Methods: This multi-institutional retrospective study included patients who underwent RAPN at tertiary surgery centers. Patients were first stratified into High, Intermediate, and Low categories based on renal nephrometry score. Patients were further classified into I/B-enucleation (I/B-E, I + B ≤ 1) and I/B-resection (I/B-R, I + B ≥ 2) groups based on surface-intermediate-base margin score. Perioperative outcomes, including percentile change in estimated glomerular filtration rate (eGFR), new-onset chronic kidney disease, complication rate, surgical margin, and trifecta achievement, were compared between the I/B-E and I/B-R groups in each category. Odds ratios (ORs) and β-coefficients were also compared. Results: Overall, 704 patients were included in this study. Relative decrease in eGFR was significantly lower for the I/B-E group in all three categories, with medians of 8.1%, 4.4%, and 3.2% in the High, Intermediate, and Low, respectively. In multivariate analyses, excision technique was independently associated with eGFR change in all three. β-coefficient was higher in the High (5.06) category than in the Low (3.17) or Intermediate (3.33). Across all three categories, significantly more patients attained trifecta with a difference of 34.0%, 18.3%, and 15.1% in the High, Intermediate, and Low categories, respectively (all, p < 0.05), with a higher OR in the High (5.91) category than in the Low (3.20) or Intermediate (2.48). No significant differences were found in operation time, amount of estimated blood loss, rate of positive surgical margin, or complications. Warm ischemic time was significantly longer for the I/B-E group in the Intermediate (18.0 minutes vs 16.0 minutes, p = 0.002) and Low categories (13.0 vs 11.0, p = 0.006), but not significant in High (p = 0.344). Conclusions: I/B-enucleation in RAPN contributes to renal function preservation, and the impact was more emphasized in complex tumors.

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.

Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy using enhanced MDCT

To investigate the detection of peritumoral pseudocapsule (PC) using multi-detector row computed tomography (MDCT) for tumors resected by robot-assisted laparoscopic partial nephrectomy (RAPN) for T1 renal cell carcinoma (RCC). Study participants included 206 patients with clinical T1 RCC who underwent RAPN between October 2017 and February 2018. Two radiologists who were blinded to the pathological findings evaluated the computed tomography (CT) images. Radiological diagnosis of a PC was defined by a combination of observations, including a low-attenuation rim between the tumor and renal cortex in the cortico-medullary phase and a high-attenuation rim at the edge of the tumor in the nephrogenic or excretory phase. A PC was detected on CT in 156/206 tumors (76%) and identified by pathology in 182/206 (88%) tumors including 153/166 (92%) clear cell RCC, 13/14 (93%) papillary RCC, and 7/16 (44%) chromophobe RCC. In the whole cohort, CT findings showed a sensitivity of 81.3% (148/182), specificity of 66.7% (16/24), and positive predictive value of 94.9% (148/156). When the data were stratified according to pathological subtypes, MDCT was observed to have a sensitivity of 86.9% (133/153) and specificity of 61.5% (8/13) in clear cell RCC, sensitivity of 38.5% (5/13) and specificity of 100% (1/1) in papillary RCC, and sensitivity of 44.4% (4/7) and specificity of 66.7% (6/9) in chromophobe RCC. A low or high-attenuation rim around the tumor in the cortico-medullary or nephrographic-to-excretory phase indicates a PC of RCC, though the accuracy is not satisfactory even with 64- or 320-detector MDCT.

Long-Term Oncologic Outcomes After Laparoscopic and Robotic Tumor Enucleation for Renal Cell Carcinoma

OBJECTIVES

Tumor enucleation (TE) optimizes parenchymal preservation with promising short-term oncologic outcomes compared with standard partial nephrectomy (SPN). However, researches/literatures about long-term oncologic outcomes for TE after minimally invasive surgery are scarce. We aim to analyze long-term oncologic outcomes after laparoscopic and robotic tumor enucleation for renal cell carcinoma (RCC).

PATIENTS AND METHODS

We retrospectively analyzed 146 patients who underwent TE with either laparoscopic or robotic approach for localized RCC in our center. Local recurrence, cancer specific survival (CSS), recurrence free survival (RFS), and overall survival (OS) were the main outcomes. Survival curves were generated using a Kaplan-Meier method. Perioperative outcomes and pathological outcomes were also analyzed.

RESULTS

Overall, 98 male and 48 female patients were eligible for the study. The median tumor size was 3.4 cm with a median R.E.N.A.L. score of seven. Warm ischemia was used in 143 patients with a median ischemia time of 20 min and three patients had zero ischemia. Five patients (3.4%) had major complications (> Clavien IIIa) and only two were related to urinary system. The median global glomerular filtration rate (GFR) preserved after surgery was 93%. Pseudocapsule invasion was reported in 50 tumors (34%) and positive surgical margins were found in 3/146 (2.1%) tumors. At a median follow-up of 66 months, local recurrence happened in two patients (1.4%), and systemic recurrence happened in six patients (4.2%). The 5-year CSS, RFS, OS were 95.7, 89.6, and 91.9%, and the 10-year CSS, RFS, OS were 93.8, 89.6, and 90.0%, respectively.

CONCLUSION

This study indicates that tumor enucleation with laparoscopic or robotic approach in experienced hands for the treatment of RCC appears oncologically safe with a median follow-up of more than 5 years. Prospective studies with more patients and longer follow-up will be required to further evaluate oncologic safety after TE.

Role of minimally invasive partial nephrectomy in the management of renal mass

Partial nephrectomy is recommended for surgical management of small renal masses (SRM), or lesions ≤7 cm. The decision for surgical intervention involves a balanced patient assessment. Minimally invasive approach, which includes laparoscopic and robotic techniques, has shown to have improved blood loss, length of hospitalization, and post-operative pain while maintaining oncologic efficacy when compared to an open approach. Transperitoneal approach is preferred at most centers; however, retroperitoneoscopic minimally invasive surgery (MIS) partial nephrectomy expertise is essential for comprehensive kidney cancer care. With advances in surgical technology and deep penetration of robotics into surgical training and practice, robotic partial nephrectomy has become the modality of choice in modern clinical practice. This review discusses the indications and outcomes for various minimally invasive approaches of partial nephrectomy.

How far is too far? Exploring the indications for robotic partial nephrectomy in a highly complex kidney tumor

Purpose:

The conservative management of localized renal masses has been recently widened to cT2 tumors showing encouraging functional and oncological outcomes (1). This video aims to report the conservative management of a highly complex renal tumor treated with robotic pure enucleation in our center, specifically focusing on preoperative work-up, video-reported surgical steps and perioperative outcomes.

Materials and Methods:

A 63 year-old lady underwent CT scan revealing a single 75 x 68mm, mainly endophytic, right renal mass dislocating the vascular pedicle (cT3a). Two renal arteries and two veins were identified. PADUA, RENAL and simplified SPARE scores were 14a, 12a and 12 respectively. Since the contralateral kidney was hypotrophic, the indication for nephron-sparing approach was considered absolute. Preoperative surgical planning included the employment of 3D-virtual models (2).

Results:

Operative time was 150 minutes and warm ischemia time was 25 minutes. No major complication occurred. Histopathological analysis revealed a cromophobe renal cell carcinoma with extension to perirenal fat tissue (pT3a). Resection technique was classified as pure enucleation since Surface-Intermediate-Base (SIB) score was 0-0-0 (3, 4). At seven-months follow-up no signs of local or systemic recurrence were recorded. Postoperative CT-scan revealed optimal parenchymal volume preservation with last creatinine blood level of 1.16mg/dL.

Conclusion:

This video highlights how, in experienced hands, robotic partial nephrectomy represents a feasible, effective treatment option for surgical management of highly complex renal tumors. The employment of intraoperative ultrasonography and 3D-virtual models allowed to accurately tailor surgical approach, improving the perception of tumor anatomy and its vascularization and maximizing perioperative outcomes.

Impact of positive surgical margins on survival after partial nephrectomy in localized kidney cancer: analysis of the National Cancer Database

BACKGROUND

The impact of positive surgical margins (PSM) on outcomes in partial nephrectomy (PN) is controversial. We investigated impact of PSM for patients undergoing PN on overall survival (OS) in different stages of renal cell carcinoma (RCC).

METHODS

Retrospective analysis of patients from the US National Cancer Database who underwent PN for cT1a-cT2b N0M0 RCC between 2004-13. Patients were stratified by pathological stage (pT1a, pT1b, pT2a, pT2b, and pT3a [upstaged]) and analyzed by margin status. Cox Regression multivariable analysis (MVA) was performed to investigate associations of PSM and covariates on all-cause mortality (ACM). Kaplan-Meier analysis (KMA) of OS was performed for PSM versus negative margin (NSM) by pathological stage. Sub-analysis of Charlson Comorbidity Index 0 (CCI=0) subgroup was conducted to reduce bias from comorbidities.

RESULTS

We analyzed 42,113 PN (pT1a: 33,341 [79.2%]; pT1a, pT1b: 6689 [15.9%]; pT2a: 757 [1.8%]; pT2b: 165 [0.4%]; and pT3a: upstaged 1161 [2.8%]). PSM occurred in 6.7% (2823) (pT1a: 6.5%, pT1b: 6.3%, pT2a: 5.9%, pT2b: 6.1%, pT3a: 14.1%, P<0.001). On MVA, PSM was associated with 31% increase in ACM (HR 1.31, P<0.001), which persisted in CCI=0 sub-analysis (HR: 1.25, P<0.001). KMA revealed negative impact of PSM vs. NSM on 5-year OS: pT1 (87.3% vs. 90.9%, P<0.001), pT2 (86.7% vs. 82.5%, P=0.48), and upstaged pT3a (69% vs. 84.2%, P<0.001).

CONCLUSIONS

PSM after PN was independently associated with across-the-board decrement in OS, which worsened in pT3a disease and persisted in sub-analysis of patients with CCI=0. PSM should prompt more aggressive surveillance or definitive resection strategies.

Acute kidney injury in solitary kidney patients after partial nephrectomy: incidence, risk factors and prediction

Background

To analyze the incidence and risk factors of acute kidney injury (AKI) after partial nephrectomy (PN) in patients with solitary kidney, and to build AKI prediction models using logistic regression and machine learning (ML) approaches.

Methods

Clinical data of 87 solitary kidney patients with renal mass who received PN from January 2003 to March 2019 were collected. The diagnosis of AKI was based on KDIGO criteria. Logistic regression analysis and ML method were used to build prediction models.

Results

AKI developed in 52 (59.8%) patients. The logistic regression model had three variables: ischemia time (P=0.003), surgery time (P=0.001) and preoperative fasted blood glucose level (FBG) (P=0.049). The area under curve (AUC) was 0.826, with the specificity and sensitivity of optimal threshold value 82.9% and 69.2%. The ML model had the following variables: ischemia time, surgery time, age, FBG, mean arterial pressure (MAP), colloid, crystalloid, etc. XGBoost model has the best prediction performance. The AUC was 0.749, lower than that of the logistic regression model with no statistical difference (P=0.258), with the specificity and sensitivity 62.9% and 84.6%, respectively.

Conclusions

The incidence of AKI after PN in patients with a solitary kidney was relatively high, it was associated with longer ischemia time, surgery time and higher FBG level, etc. The performance of ML model had no significant difference with logistic regression model. Prospective studies with larger sample sizes are awaited to test and verify our research findings.

Toward Individualized Approaches to Partial Nephrectomy: Assessing the Correlation Between Ischemia Time and Patient Health Status (RECORD2 Project)

BACKGROUND

Ischemia time during partial nephrectomy (PN) is among the greatest determinants of acute kidney injury (AKI). Whether this association is affected by the preoperative risk of AKI has never been investigated.

OBJECTIVE

To assess the effect of the interaction between the preoperative risk of AKI and ischemia time on the probability of AKI during PN.

DESIGN, SETTING, AND PARTICIPANTS

Data of 944 patients treated with on-clamp PN for cT1 renal tumors were extracted from the Registry of Conservative and Radical Surgery for Cortical Renal Tumor Disease (RECORD2) database, a prospective multicenter project.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We estimated the preoperative risk of AKI (defined according to the risk/injury/failure/loss/end-stage [RIFLE] criteria) according to age, baseline renal function, clinical stage, preoperative aspects and dimensions used for an anatomical (PADUA) score, and surgical approach. Classification and regression tree (CART) analysis identified patients at "high" and "low" risk of AKI. Finally, we plotted the probability of AKI over ischemia time stratified by the preoperative risk of AKI.

RESULTS AND LIMITATIONS

Overall, 235 (25%) patients experienced AKI after surgery. At multivariable analysis, older patients, those with more complex tumors, those with higher baseline function, and those treated with open surgery had an increased risk of AKI (all p ≤ 0.011). According to the first split at CART analysis, patients were categorized as those with "high" and "low" risk of AKI having a probability of >40% or <40%. For low-risk patients, the probability of AKI in case of <10 versus >20 min of ischemia was 13% versus 28% (absolute risk increase 15%). The risk of AKI for high-risk patients who had <10 versus >20 min of ischemia was 31% versus 77%. This corresponds to an absolute risk increase of 45%. Limitations include retrospective data analyses and lack of surgeons' prior experience.

CONCLUSIONS

Ischemia time during PN has different implications for patients with different health status. Clamp time seems less clinically relevant for patients in good conditions who may endure prolonged ischemia with a mild increase in the risk of AKI, whereas frail patients seem to be more vulnerable to ischemic damage even for short clamp time. For individualized intra- and postoperative management, duration of ischemia needs to be questioned in the context of the individual health status.

PATIENT SUMMARY

Functional sequelae related to ischemia time during partial nephrectomy depend on baseline health status. The correlation between the duration of ischemia and baseline health status should be taken into account toward individualized intra- and postoperative management.

Robot-Assisted Laparoscopic Partial Nephrectomy Vs Conventional Laparoscopic Partial Nephrectomy: Functional and Surgical Outcomes of a Prospective Single Surgeon Randomized Study

Background: Laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN) are commonly used techniques for treating small renal masses. Regarding renal function (RF) preservation, no superiority of one technique over the other has yet been definitely demonstrated. Objective: To compare functional and surgical outcomes of LPN and RAPN. Patients and Methods: Between 2015 and 2019, we prospectively randomized 115 patients with cT1-T2 renal masses to LPN in total ischemia or RAPN in selective ischemia. Primary endpoint was RF preservation, assessed by renal scintigraphy (RS). RS assessments were performed preoperatively and at 6 months follow-up. Secondary endpoints included clinical, histopathologic, and surgical outcomes. Results: One hundred eight patients were included in the final analysis. Patient and tumor characteristics were comparable. No significant difference in RS values after 6 months was observed between both groups. Median (interquartile range) RF change after 6 months was -18.0% (-26.5 to -11.0) in LPN group and -20.0 (-33.2 to -12.0) in RAPN group (p = 0.3). Mean (standard deviation [SD]) warm ischemia time was 21.1 (6.1) minutes in LPN group and 19.6 (7.7) minutes in RAPN group (p = 0.2). No positive surgical margins (PSMs) occurred in the LPN group, whereas RAPN group had PSM in 4.9% (n = 3); p = 0.099. Renal volume loss after 6 months was 27.5% (22.7-45.7) in the LPN group vs 37.5 (13.7-54.2) in the RAPN group (p = 0.5). Mean operative times were lower in the LPN group (192.3 minutes [SD 44.5] vs 230.2 minutes [SD 59.6], p = 0.001). More complications occurred in the LPN group (31% vs 21%, p = 0.075). Transfusion rates were 15% for LPN and 11% for RAPN. Conclusions: In terms of preserving RF, LPN in total ischemia and RAPN in selective ischemia are comparable. In most patients, RF decrease of the affected kidney after PN seems to not exceed 25%, regardless of the surgical approach.

Renal Volume Loss During Partial Nephrectomy Due to Resected Healthy Parenchyma: A Tool for Quick Estimation

Purpose: Our objective is to evaluate a technique for estimating the amount of healthy margin resected during partial nephrectomy (PN). Materials and Methods: The resected healthy margin volume was determined by planimetry (gold standard), which was performed in a prospective manner on 30 freshly resected renal masses by cross-sectional slicing every ∼5 mm. A single cross-sectional slice containing the largest tumor diameter (bivalved tumor) was chosen to build a model for estimating the amount of healthy kidney removed. This single-slice technique was then applied to a second series of patients (n = 39) status post PN. Three-dimensional models were created using pre- and postoperative CT scans to determine the overall volume loss following PN. Results: The median (range) for tumor diameter and tumor volume was 3.2 cm (1-6.1) and 10.7 cm³ (0.5-101.9), respectively, for the 30 PN specimens used to build the single-slice estimation equation. The median (range) healthy margin volume calculated by planimetry and single slice technique was 9.0 cm³ (1.0-22.1) and 7.8 cm³ (1.0-31.0), respectively (p = 0.37). The Pearson correlation was 0.84, and the median (range) percent difference between the planimetry and single slice techniques was -0.5% (-39% to 57%). For the 39 PN patients, the median (range) total renal volume loss, 25.8 cm³ (3-79), was significantly greater than the volume of healthy margin removed during resection, 5.7 cm³ (1-22), p < 0.001. Conclusions: The healthy margin resected during PN differs widely and can be estimated from a single cross-section. The healthy margin resected accounted for <50% of the total volume loss seen during PN.

On-clamp versus off-clamp robotic partial nephrectomy: A systematic review and meta-analysis

BACKGROUND

The debate on the pros and cons of robot-assisted partial nephrectomy performed with (on-clamp) or without (off-clamp) renal artery clamping is ongoing. The aim of this meta-analysis is to summarize the available evidence on the comparative studies assessing the outcomes of these two approaches.

MATERIAL AND METHODS

A systematic review of the literature on PubMed, ScienceDirect^®, and Embase^® was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement (PRISMA). Only comparative and case-control studies were submitted to full-text assessment and meta-analysis. RevMan 5.3 software was used.

RESULTS

From the initial retrieval of 1937 studies, 15 fulfilling inclusion criteria were selected and provided 2075 patients for analysis (702 off-clamp, 1373 on-clamp). Baseline tumor's features showed a significant difference in size (weighted mean difference: -0.58 cm; 95% confidence interval: [-1.06, -0.10]; p = 0.02) and R.E.N.A.L. score (weighted mean difference: -0.53; 95% confidence interval: [-0.81, -0.25]; p = 0.0002), but not in the exophytic property, the location, and the PADUA score. Pooled analysis revealed shorter operative time (p = 0.02) and higher estimated blood loss (p = 0.0002) for the off-clamp group. Overall complication and transfusion rates were similar, while higher major complication rate was observed in the on-clamp approach (5.6% vs 1.9%, p = 0.03). No differences in oncological outcomes were found. Finally, functional outcomes (assessed by estimated glomerular filtration rate at early postoperative, 3 month, 6 month, and last available follow-up) were not statistically different.

CONCLUSION

This meta-analysis shows that off-clamp robot-assisted partial nephrectomy is reserved to smaller renal masses. Under such conditions, no differences with the on-clamp approach emerged.

Predictors of early postoperative and mid-term functional outcomes in patients treated with Endoscopic Robot-Assisted Simple Enucleation (ERASE): results from a tertiary referral center

BACKGROUND

The aim of this study was to assess the early and mid-term functional outcomes of Endoscopic Robot Assisted Simple Enucleation (ERASE) verified through a standardized tumor-resection reporting system (Surface Intermediate Base [SIB] score) and to investigate for predictors of renal function (RF) loss in patients with T1 renal tumors treated in a tertiary referral institution.

METHODS

Data of 553 patients treated with ERASE were analyzed. Only patients with SIB score of 0-1 and negative oncological follow-up were included. A ≥25% drop from baseline of estimated glomerular filtration rate (eGFR) was considered as a clinically meaningful functional loss. Multivariable regression models tested the relation between clinical features and RF loss at postoperative day (POD) 3 and at last follow-up.

RESULTS

Overall, 347 patients with SIB 0-1 entered the study. A RF drop ≥25% was observed in 178 (37%) patients in POD 3 and in 91 (18.9%) patients at a median follow-up of 36 months, respectively. At multivariable analysis, age at surgery and PADUA score were significant predictive factors of clinically significant RF loss at POD 3, while age at surgery, female gender, higher BMI, Charlson Comorbidity Index (CCI) and preoperative eGFR were significant predictors of RF loss at last follow-up.

CONCLUSIONS

Age at surgery and higher PADUA score are significant predictors of early postoperative RF loss after ERASE for T1 renal tumors, while age at surgery, female gender, higher BMI, CCI and baseline RF significantly affect mid-term RF. Larger studies and a longer follow-up are needed to confirm these results.

Perioperative Outcomes of Open, Laparoscopic, and Robotic Partial Nephrectomy: A Prospective Multicenter Observational Study (The RECORd 2 Project)

BACKGROUND

Partial nephrectomy (PN) has a non-negligible perioperative morbidity. Comparative evidence of the available surgical techniques is limited.

OBJECTIVE

To compare the perioperative outcomes of open, laparoscopic, and robotic PN.

METHODS

Data of 2331 patients treated with PN for cT1 renal tumors were extracted from the RECORd2 database, a prospective multicenter project. Multivariable regression models assessed the relationship between surgical technique and surgical margins, warm ischemia time, postoperative complications, and acute kidney injury (AKI). The probability of achieving a modified trifecta (negative margins, warm ischemia time <25min, and no Clavien-Dindo ≥2 complications) was examined for each surgical approach.

RESULTS

Minimally invasive techniques had lower rate of Clavien-Dindo ≥2 complications than that of open surgery (odds ratio [OR] for robotic surgery: 0.27; 95% confidence interval [95% CI]: 0.15-0.47, p< 0.0001; OR for laparoscopy: 0.52; 95% CI: 0.34-0.78; p= 0.002). The probability of receiving ischemia was highest for robotic PN (p< 0.001). Among on-clamp PN, laparoscopy had longer ischemia than open (estimate: 1.09; 95% CI: -0.00 to 2.18; p= 0.050) and robotic (estimate: 1.36; 95% CI: 0.31-2.40; p= 0.011) surgery. When compared with open PN, the risk of AKI was roughly halved for patients treated by robotic and laparoscopic surgery (both p< 0.0001). Positive margins rate did not differ between the groups (all p≥ 0.1). The likelihood to achieve a modified trifecta was not affected by surgical technique in the overall population (all p≥ 0.075). In Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score < 10 lesions, robotic surgery had higher probability of achieving a modified trifecta than open PN (OR: 1.66; 95% CI: 1.09-2.53; p= 0.018) and laparoscopy (OR: 1.34; 95% CI: 0.94-1.90; p= 0.11).

CONCLUSIONS

In PADUA<10 renal tumors, robotic PN allows for higher rates of trifecta than open and laparoscopic surgeries. The impact of surgical technique on perioperative outcomes of PN might be limited in more complex lesions.

PATIENT SUMMARY

We evaluated the association between surgical technique and perioperative outcomes of partial nephrectomy. In less complex (Preoperative Aspects and Dimensions Used for an Anatomical [PADUA] score < 10) lesions, robotic PN allows for higher rates of trifecta when compared with other surgical techniques.

Safety of on- vs off-clamp robotic partial nephrectomy: per-protocol analysis from the data of the CLOCK randomized trial

PURPOSE

To compare the safety of on- vs off-clamp robotic partial nephrectomy (RAPN).

METHODS

302 patients with RENAL masses ≤ 10 were randomized to undergo on-clamp (150) vs off-clamp (152) RAPN (CLOCK trial-ClinicalTrials.gov NCT02287987) at seven institutions by one experienced surgeon per institution. Intra-operative data, complications, and positive surgical margins were compared.

RESULTS

Due to a relevant rate of shift from the assigned treatment, the per-protocol analysis only was considered and the data from 129 on-clamp vs 91 off-clamp RAPNs analyzed. Tumor size (off-clamp vs on-clamp, 2.2 vs 3.0 cm, p < 0.001) and RENAL score (5 vs 6, p < 0.001) significantly differed. At univariate analysis, no differences were found regarding intra-operative estimated blood loss (off- vs on-clamp, 100 vs 100 ml, p = 0.7), post-operative complications rate (19% vs 26%, p = 0.2), post-operative anemia (Hb decrease > 2.5 g/dl 26% vs 27%, p = 0.9; transfusion rate 3.4% vs 6.3%, p = 0.5; re-intervention due to bleeding 1.1% vs 4%, p = 0.4), acute kidney injury (4% vs 6%, p = 0.8), and positive surgical margins (3.5% vs 8.2%, p = 0.1). At multivariate analysis accounting for tumor diameter and complexity, considering the on-clamp group as the reference category, a significant difference was noted in the off-clamp group exclusively for blood loss (OR 0.3, 95% CI 0.09-0.52, p = 0.008).

CONCLUSIONS

The on-clamp and off-clamp approaches for RAPN showed a comparable safety profile.

The feasibility and safety of modified robot-assisted enucleation for highly complex renal tumors: research on a surgical technique

BACKGROUND

To report the technical feasibility and oncological safety of modified robot-assisted enucleation for highly complex renal tumors using the combined retroperitoneoscopic and transperitoneoscopic accesses.

METHODS

The present research is a retrospective analysis of 166 cases of highly complex renal tumors that underwent a partial nephrectomy at a tertiary academic institution between September 2014 and August 2017. Consecutive consented patients were grouped into two cohorts. Seventy-two cases underwent conventional robot-assisted partial nephrectomy (C-RAPN), and 94 cases were treated with modified robot-assisted tumor enucleation (MRATE). The perioperative and oncological outcomes of both groups were reported. Furthermore, pathological examinations of 225 cases of highly complex renal tumors treated with radical nephrectomy were analyzed.

RESULTS

Although preoperative clinical data were similar between the two groups, the perioperative outcomes were distinctly different. Total renal function at postoperative day 1 was better (P<0.001), and the surgical margin width was narrower (P<0.001) in the MRATE group. In addition, the MRATE group presented less blood loss (143.29 and 90.76 mL; P<0.001) and lower 30-d complication rates (4.2% and 16.7%, respectively; P=0.033). Mean ischemia time and operative time was 3 and 14 minutes shorter in the MRATE group, respectively. Finally, histopathological analysis of 225 cases of renal tumors with high surgical complexity provided objective evidence for the feasibility of MRATE.

CONCLUSIONS

MRATE technique may offer an efficient and safe method to treat anatomically complex renal masses in referral centers. The long-term outcome of MRATE technique merits further investigation.

Tumor Enucleation Is Appropriate During Partial Nephrectomy

Tumor enucleation is oncologically safe and has the potential to meet the essential requirements for conservative surgery: (1) to widen the indications to tumors with unfavorable nephrometry; (2) to be well suited for minimally invasive surgery; and (3) to maximize the volume of parenchyma preserved.

Suture techniques during laparoscopic and robot-assisted partial nephrectomy: a systematic review and quantitative synthesis of peri-operative outcomes

OBJECTIVE

To summarize the available evidence on renorrhaphy techniques and to assess their impact on peri-operative outcomes after minimally invasive partial nephrectomy (MIPN).

MATERIALS AND METHODS

A systematic review of the literature was performed in January 2018 without time restrictions, using MEDLINE, Cochrane and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement recommendations. Studies providing sufficient details on renorrhaphy techniques during laparoscopic or robot-assisted partial nephrectomy and comparative studies focused on peri-operative outcomes were included in qualitative and quantitative analyses, respectively.

RESULTS

Overall, 67 and 19 studies were included in the qualitative and quantitative analyses, respectively. The overall quality of evidence was low. Specific tumour features (i.e. size, hilar location, anatomical complexity, nearness to renal sinus and/or urinary collecting system), surgeon's experience, robot-assisted technology, as well as the aim of reducing warm ischaemia time and the amount of devascularized renal parenchyma preserved represented the key factors driving the evolution of the renorrhaphy techniques during MIPN over the past decade. Quantitative synthesis showed that running suture was associated with shorter operating and ischaemia time, and lower postoperative complication and transfusion rates than interrupted suture. Barbed suture had lower operating and ischaemia time and less blood loss than non-barbed suture. The single-layer suture technique was associated with shorter operating and ischaemia time than the double-layer technique. No comparisons were possible concerning renal functional outcomes because of non-homogeneous data reporting.

CONCLUSIONS

Renorrhaphy techniques significantly evolved over the years, improving outcomes. Running suture, particularly using barbed wires, shortened the operating and ischaemia times. A further advantage could derive from avoiding a double-layer suture.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Tumor-parenchyma interface and long-term oncologic outcomes after robotic tumor enucleation for sporadic renal cell carcinoma

OBJECTIVE

Tumor enucleation has been shown to be oncologically safe for elective treatment of renal cell carcinoma (RCC); yet, evidence on long-term oncologic outcomes after robotic tumor enucleation is lacking. In this study we provide a detailed histopathological analysis of tumor-parenchyma interface and the long-term oncologic outcomes after robotic tumor enucleation for sporadic RCC in a high-volume referral center.

MATERIALS AND METHODS

We selected consecutive patients undergoing robotic tumor enucleation for sporadic RCC by experienced surgeons with at least 4 years of follow-up. Pattern of pseudocapsule (PC) invasion, thickness of healthy renal margin removed with the tumor, margin status and recurrence rate were the main study endpoints. Multivariable models evaluated independent predictors of PC invasion.

RESULTS

Overall, 140 patients were eligible for the study. Of these, 127 (91%) had complete data available for analysis. Median thickness of healthy renal margin was 0.57 mm (interquartile range [IQR] 0.24-103). A distinct peritumoral PC was present in 121/127 (95%) tumors with a median thickness of 0.28 mm (IQR 0.14-0.45). In 24/121 (19.8%) cases, RCC showed complete PC invasion. At multivariable analysis, increasing tumor diameter, endophytic rate > 50% and papillary histology were significantly associated with complete PC invasion. Positive surgical margins were reported in 3/127 (2.4%) cases. At a median follow-up of 61 months (range 48-76), one patient died due to metastatic RCC. Among patients alive at follow-up, no cases of recurrence at the enucleation site were recorded, while three cases (2.4%) of renal recurrence (elsewhere in the ipsilateral kidney) and three cases (2.4%) of systemic recurrence were found.

CONCLUSIONS

Distinct RCC-related features were associated with complete PC invasion. By providing a microscopic layer of healthy renal margin in almost all cases, robotic tumor enucleation achieved negative surgical margins in the vast majority of patients, even in case of complete PC invasion. At long-term follow-up, no recurrences were found at the enucleation site. Although our findings need to be confirmed by larger studies with longer follow-up, robotic tumor enucleation appears oncologically safe in experienced hands for the treatment of sporadic RCC.