Tumor Enucleation vs. Partial Nephrectomy for T1 Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Comparing the oncologic outcomes of local tumor destruction vs. local tumor excision vs. partial nephrectomy in T1a solid renal masses: a population-based cohort study from the SEER database

BACKGROUND

There are few large-scale analyses comparing local tumor destruction (LTD) or local tumor enucleation/excision (LTE) relative to partial nephrectomy (PN) for patients with T1a renal masses in terms of cancer-specific survival (CSS) and overall survival (OS). The authors aimed to compare CSS and OS after LTD versus LTE versus PN.

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019), the authors identified patients with clinical T1a renal masses and histologically confirmed kidney cancer treated with LTD, LTE, or PN. After 1:1 ratio propensity score matching (PSM), comparisons between the groups were conducted. Kaplan-Meier analysis and log-rank tests were used to compare survival in the matched population.

RESULTS

In the overall cohort of 3717 LTD patients versus 1993 LTE patients versus 26 935 PN patients, 77.3% of LTD-treated patients and 74.4% of LTE-treated patients were over 60 years old, while only 50.3% of PN-treated patients were over 60 years old. PN was more strongly associated with CSS [hazard ratio ((HR)=1.276, P <0.001) and OS (HR=1.112, P <0.001)] than was LTD, while PN was less strongly associated with CSS (HR=1.040, P =0.230) and OS (HR=0.888, P =0.002) than was LTE, not only in the PSM cohort but also in the subgroups of patients with a tumor size ≤3 cm and patients with a tumor size of 3.1-4 cm.

CONCLUSIONS

In clinical T1a solid renal mass patients, LTD was associated with lower CSS and OS than LTE and PN, while LTE demonstrated noninferior CSS and superior OS to PN regardless of tumor size.

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.

Visualization modality for augmented reality guidance of in-depth tumour enucleation procedures

Recent research studies reported that the employment of wearable augmented reality (AR) systems such as head-mounted displays for the in situ visualisation of ultrasound (US) images can improve the outcomes of US-guided biopsies through reduced procedure completion times and improved accuracy. Here, the authors continue in the direction of recent developments and present the first AR system for guiding an in-depth tumour enucleation procedure under US guidance. The system features an innovative visualisation modality with cutting trajectories that 'sink' into the tissue according to the depth reached by the electric scalpel, tracked in real-time, and a virtual-to-virtual alignment between the scalpel's tip and the trajectory. The system has high accuracy in estimating the scalpel's tip position (mean depth error of 0.4 mm and mean radial error of 1.34 mm). Furthermore, we demonstrated with a preliminary user study that our system allowed us to successfully guide an in-depth tumour enucleation procedure (i.e. preserving the safety margin around the lesion).

Risk of pseudoaneurysm and bleeding complications after partial nephrectomy: comparison of tumor enucleation to standard margin technique

Partial nephrectomy (PN) is the gold standard for the resection of amenable small renal masses. Some surgeons have adopted tumor enucleation (TE) over the standard margin PN (SPN) technique based on preservation of healthy renal parenchyma by following the tumor pseudocapsule. However, TE may also confer additional advantages due to avoidance of sharp incision including reduction in perioperative and bleeding complications. Therefore, we evaluated the rate of pseudoaneurysms and other complications following TE vs. SPN. A retrospective cohort study of patients undergoing PN (TE and SPN) between 2008 and 2020 was conducted. Baseline characteristics were compared between the TE and SPN cohorts with univariable and multivariable logistic regression models. A total of 534 patients were included, 195 (36.5%) receiving TE and 339 (63.5%) SPN. There were no differences in baseline patient demographics. There was no difference in RENAL nephrometry scores between the two groups (p = 0.47). TE had lower rates of postoperative complications (11.3 vs. 21.5%, p = 0.002). TE had less bleeding complications (2.1 vs. 8.0%, p = 0.002) with no pseudoaneurysm events following TE compared to 12 following SPN (0.0 vs. 3.5%, p = 0.008). Need for interventional radiology largely reflected pseudoaneurysm differences (0 (0.0%) TE vs. 13 (3.8%) SPN, p = 0.006. Readmission occurred less often after TE vs. SPN (4.1 vs. 8.3%, p = 0.07). Patients receiving TE experienced no clinically significant pseudoaneurysm formation and were less likely to have any bleeding complication or major complication postoperatively. TE may be preferred when minimizing morbidity aligns with patient selection and preferences.

Long-Term Renal Function Following Renal Cancer Surgery: Historical Perspectives, Current Status, and Future Considerations

Knowledge of functional recovery after partial (PN) and radical nephrectomy for renal cancer has advanced considerably, with PN now established as the reference standard for most localized renal masses. However, it is still unclear whether PN provides an overall survival benefit in patients with a normal contralateral kidney. While early studies seemingly demonstrated the importance of minimizing warm-ischemia time during PN, multiple new investigations over the last 10 years have proven that parenchymal mass lost is the most important predictor of new baseline renal function. Minimizing loss of parenchymal mass during resection and reconstruction is the most important controllable aspect of long-term post-operative renal function preservation.

A survey of augmented reality methods to guide minimally invasive partial nephrectomy

INTRODUCTION

Minimally invasive partial nephrectomy (MIPN) has become the standard of care for localized kidney tumors over the past decade. The characteristics of each tumor, in particular its size and relationship with the excretory tract and vessels, allow one to judge its complexity and to attempt predicting the risk of complications. The recent development of virtual 3D model reconstruction and computer vision has opened the way to image-guided surgery and augmented reality (AR).

OBJECTIVE

Our objective was to perform a systematic review to list and describe the different AR techniques proposed to support PN.

MATERIALS AND METHODS

The systematic review of the literature was performed on 12/04/22, using the keywords "nephrectomy" and "augmented reality" on Embase and Medline. Articles were considered if they reported surgical outcomes when using AR with virtual image overlay on real vision, during ex vivo or in vivo MIPN. We classified them according to the registration technique they use.

RESULTS

We found 16 articles describing an AR technique during MIPN procedures that met the eligibility criteria. A moderate to high risk of bias was recorded for all the studies. We classified registration methods into three main families, of which the most promising one seems to be surface-based registration.

CONCLUSION

Despite promising results, there do not exist studies showing an improvement in clinical outcomes using AR. The ideal AR technique is probably yet to be established, as several designs are still being actively explored. More clinical data will be required to establish the potential contribution of this technology to MIPN.

Imaging Features of Renal Masses to Select Optimal Candidates for Tumor Enucleation Partial Nephrectomy

PURPOSE OF REVIEW

The goal of this paper was to critically evaluate preoperative findings that optimally select candidates for renal tumor enucleation partial nephrectomy.

RECENT FINDINGS

Tumor enucleation has been widely accepted as a management option for patients with chronic kidney disease, hereditary renal cell carcinoma, or multifocal disease. Recent evidence suggests safety and efficacy in the management of routine small renal masses. With recent advances in imaging, the literature for ruling out aggressive renal cell carcinoma and selection for tumor enucleation is robust. As the incidence of renal cell carcinoma rises, partial nephrectomy continues to be the mainstay of treatment for localized renal cell carcinoma. Tumor enucleation maximizes preservation of renal parenchyma without hindering oncologic outcomes. It is important to recognize key tumor radiologic findings which urologists may use to optimize patient selection for tumor enucleation.

Comparison of surgical outcomes and split renal function between laparoscopic and robot-assisted partial nephrectomy: a propensity score-matched analysis

PURPOSE

The objective of this study was to compare perioperative outcomes and total and split renal function between laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN). Predictive risk factors of preservation of operated renal function were also assessed.

METHODS

We retrospectively analyzed 173 patients who underwent LPN (n = 84) or RAPN (n = 89) between 2010 and 2020. After propensity score matching (1:1), perioperative outcomes and total and split renal function were assessed. Logistic regression analysis was used to evaluate predictive risk factors of preservation of operated renal function. Trifecta criteria were defined as negative surgical margins, warm ischemia time (WIT) < 25 min, and no complications more than Clavien-Dindo grade II within 4 weeks after surgery. Split renal function was evaluated by mercaptoacetyltriglycine renal scan.

RESULTS

After propensity score matching, 42 patients were allocated to each group. RAPN was associated with significantly shorter WIT (RAPN vs LPN: 12 vs 22 min; p < 0.0001) and higher trifecta achievement rate (93.3 vs 64.2%; p < 0.0001). Other perioperative outcomes and total and split renal function were not significantly different between LPN and RAPN. The R.E.N.A.L. nephrometry score (RNS) was a predictive risk factor of preservation of operated renal function in the multivariable logistic regression analysis (odds ratio 1.68, 95% confidence interval 1.29-2.20, p < 0.0001).

CONCLUSIONS

RAPN improved WIT and trifecta achievement rate, but it did not improve the preservation of operated renal function, for which RNS was found to be a strong predictive risk factor.

Tumor enucleation for the treatment of T1 renal tumors: A systematic review and meta-analysis

Purpose

To evaluate the clinical efficacy and safety of tumor enucleation (TE) compared with partial nephrectomy (PN) for T1 renal cell carcinoma.

Materials and Methods

According to protocol, we searched multiple data sources for published and unpublished randomized controlled trials and nonrandomized studies (NRSs) in any language. We performed systematic review and meta-analysis according to the Cochrane Handbook for Systematic Reviews of Interventions and rated the certainty of the evidence (CoE) using the GRADE framework.

Results

We are uncertain about the effects of TE on perioperative (mean difference [MD] 3.38, 95% CI 1.52 to 5.23; I²=68%; 4 NRSs; 942 participants; very low CoE) and long-term (MD 2.31, 95% CI -1.40 to 6.01; I²=57%; 4 NRSs; 542 participants; very low CoE) residual renal function. TE may result in little to no difference in short-term residual renal function (MD 1.04, 95% CI 0.25 to 1.83; I²=0%; 2 NRSs; 256 participants; low CoE). We are uncertain about the effects of TE on cancer-specific mortality (risk ratio [RR] 0.90, 95% CI: 0.11 to 7.28; I²=0%; 2 NRSs; 551 participants; very low CoE) and major adverse events (RR 0.48, 95% CI: 0.30 to 0.79; I²=0%; 10 NRS; 2,360 participants; very low CoE).

Conclusions

While TE appears to have similar effects on short term postoperative residual renal function, there were uncertainties on mortality and major adverse events. However, we need rigorous RCTs to elucidate the effects of TE as the evidence stems mostly from NRSs.

Comparison of parenchymal volume loss assessed by three-dimensional computed tomography volumetry and renal functional recovery between conventional and robot-assisted laparoscopic partial nephrectomy

OBJECTIVES

We retrospectively investigated if robot-assisted laparoscopic partial nephrectomy (RAPN) contributes to a decrease in resected parenchymal volume (RPV), an increase in postoperative parenchymal volume (PPV), and an improvement of postoperative renal function when compared with conventional laparoscopic partial nephrectomy (LPN) using a three-dimensional image analysis system.

METHODS

Patients who underwent LPN (n = 37) and RAPN (n = 66) from November 2013 to November 2018 were included in this study. All patients had a tumor diameter of 4 cm or less. Patients with an anatomical or functional single kidney were excluded. RPV and PPV were measured using SYNAPSE VINCENT®. The surgical outcomes were compared between the two groups.

RESULTS

Warm ischemic time in the RAPN group was significantly shorter than that in the LPN group (p < 0.001). The ratio of RPV to tumor volume (RPV/TV) in the RAPN group was significantly lower than that in the LPN group (p = 0.016). PPV in the RAPN group was significantly higher than that in the LPN group (p = 0.049). The decreased estimated glomerular filtration rate in the RAPN group was significantly lower than that in the LPN group on days 1, 7, 30, 90, and 180 after surgery.

CONCLUSIONS

Postoperative renal function in the RAPN group was significantly better than that in the LPN group in both the short and long term. In addition to a short warm ischemia time, the decreased RPV/TV and increased PPV may have contributed to the improvement of postoperative renal function.

The Benign Renal Masses that Were Exposed after Nephron-Sparing Surgery: "Postsurgical Fatty Tumor." Is It Related to the Surgical Technique?

After nephron-sparing surgery (NSS), postsurgical fatty tumor could be mistakenly reported as angiomyolipoma during radiologic imaging of some patients. In the present paper, we studied the postsurgical fatty tumor detected after NSS but not covered before in the literature. In addition, we also evaluated whether the postsurgical fatty tumor was related to the surgical technique employed. Patients admitted to the urology department of our university hospital from 2014 to 2019 and operated with open NSS were evaluated retrospectively. We detected those 156 patients were operated with NSS. Nine patients with angiomyolipoma as primary pathology and four patients with surgical border positivity were excluded from the study. The patients were divided into two groups based on the repair of tumor extraction region. In Group 1, fatty tissue was used for repair, and Group 2 is the primary repair group. In all, 143 patients (Group 1 = 79, and Group 2 = 64) were included in the study. No demographic and radiologic differences, such as number of patients, age, gender, positioning of tumor, mass localization, tumor diameter, and RENAL nephrometry scoring system, were detected between the two groups. Postsurgical fatty tumors were detected in 28 patients in Group 1 and in two patients in Group 2 (P < 0.001). In patients with negative surgical margins after partial nephrectomy, lesions that were radiologically detected mimicking as angiomyolipoma were defined as “postsurgical fatty tumor.” This mass containing adipose tissue only neither depicted vascularization and enhancement nor increase in size for at least 1 year. We assumed that these lesions must be followed as benign lesions not requiring additional treatment.

Warm ischemia time length during on-clamp partial nephrectomy: dose it really matter?

BACKGROUND

The impact of warm ischemia time (WIT) on renal functional recovery remains controversial. We examined the length of WIT >30 min. on the long-term renal function following on-clamp partial nephrectomy (PN).

METHODS

Data from 23 centers for patients undergoing on-clamp PN between 2000 and 2018 were analyzed. We included patients with two kidneys, single tumor, cT1, minimum 1-year followup, and preoperative eGFR ≥60 ml/min/1.73m2. Patients were divided into two groups according to WIT length: group Ⅰ "WIT ≤30 min." and group Ⅱ "WIT >30 min.". A propensity-score matched analysis (1:1 match) was performed to eliminate potential confounding factors between groups. We compared eGFR values, eGFR (%) preservation, eGFR decline, events of chronic kidney disease (CKD) upgrading, and CKD-free progression rates between both groups. Cox regression analysis evaluated WIT impact on upgrading of CKD stages.

RESULTS

The primary cohort consisted of 3526 patients: group Ⅰ (n=2868) and group Ⅱ (n=658). After matching the final cohort consisted of 344 patients in each group. At last followup, there were no significant differences in median eGFR values at 1, 3, 5, and 10 years (P>0.05) between the matched groups. In addition, the median eGFR (%) preservation and absolute eGFR change were similar (89% in group Ⅰ vs. 87% in group Ⅱ, p=0.638) and (-10 in group Ⅰ vs. -11 in group Ⅱ, p=0.577), respectively. The 5 years new-onset CKD-free progression rates were comparable in the non-matched groups (79% in group Ⅰ vs. 81% in group Ⅱ, log-rank, p=0.763) and the matched groups (78.8% in group Ⅰ vs. 76.3% in group Ⅱ, log-rank, p=0.905). Univariable Cox regression analysis showed that WIT >30 min. was not a predictor of overall CKD upgrading (HR:0.953, 95%CI 0.829-1.094, p=0.764) nor upgrading into CKD stage ≥Ⅲ (HR:0.972, 95%CI 0.805-1.173, p=0.764). Retrospective design is a limitation of our study.

CONCLUSIONS

Our analysis based on a large multicenter international cohort study suggests that WIT length during PN has no effect on the long-term renal function outcomes in patients having two kidneys and preoperative eGFR ≥60 ml/min/1.73m2.

A Hemostatic Technique in Robot-Assisted Laparoscopic Partial Nephrectomy and Its Impact on Renal Function

Purpose

Robot-assisted partial nephrectomy (RAPN) has become popular in recent years for small renal masses. We describe a technique of suturing renal defects during RAPN that is reliable and quick, does not necessitate the need for hemostatic agents, and reduces perioperative complications.

Materials and methods

A total of 24 patients who underwent RAPN were included in the study period between 2013 and 2018 and data were analyzed. Perioperative and postoperative outcomes were measured and compared.

Results

The median tumor size was 4 cm. Median warm ischemia time was 41 minutes (IQR: 38-45 minutes) and estimated blood loss was 150 mL (IQR: 120-200 mL). There were no major intraoperative complications or conversions to open surgery. No urine leaks or postoperative bleedings were observed.

Conclusion

Our technique is safe and effective. It negates the use of hemostatic agents, decreases perioperative complications, and negates that determination of long-term renal function is not associated with prolonged warm ischemia time alone. Hence, we propose that our technique is safe in partial nephrectomy when the pelvic calyceal system and renal vessels are opened in multiple locations.

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.

Renorrhaphy techniques and effect on renal function with robotic partial nephrectomy

PURPOSE

The role of robotic partial nephrectomy (RPN) is becoming increasingly prevalent in managing small renal masses. Renal functional outcomes have been reported with relation to the amount of healthy renal parenchyma resected and ischemia time; however, there is limited data on the effect of renorrhaphy on long-term renal function. Our aim is to evaluate the impact of renorrhaphy technique on renal functional outcomes.

METHODS

A nonsystematic literature review was performed to retrieve articles assessing renorrhaphy techniques and renal function outcomes, specifically focusing on single-layer vs. traditional two-layer renorrhaphy.

RESULTS

Performing single-layer renorrhaphy while omitting cortical renorrhaphy appears to improve renal function postoperatively, based on very limited studies in the literature that were evaluated.

CONCLUSION

Single-layer renorrhaphy may be associated with improved postoperative renal function and could prove to be useful in patients with chronic renal insufficiency or solitary kidney. The ongoing clinical trial NCT02131376 may provide further information on the impact of renorrhaphy technique on long-term renal function.