The safety and effectiveness of laparoscopic off-clamp tumor evacuation versus traditional nephron-sparing surgery for large (>4 cm) sporadic renal angiomyolipomas

BACKGROUND

Off-clamp nephron-sparing surgery (NSS) have been selectively performed in renal tumors in which the majority are T1a (<4 cm) renal caners. Less is known, however, whether off-clamp is a safe and effective option for treatment of Sporadic Renal Angiomyolipomas (RAML), especially in those >4 cm. The objective of our study was to compare the perioperative and renal function outcomes of a novel off-clamp tumor evacuation technique versus conventional laparoscopic NSS for the treatment of large sporadic RAMLs (>4 cm).

METHODS

From January 2021 to June 2022, 42 patients diagnosed with RAML were prospectively randomized to receive laparoscopic standard NSS (Group 1) and off-clamp tumor evacuation (Group 2). The surgical and postoperative outcomes of both groups were compared.

RESULTS

Baseline characteristics demonstrated no discernible variation between Group 1 and Group 2. Compared to Group 1, Group 2 was associated shorter operative time (92.5 vs 82.3 min, p < 0.001), elimination of warm ischemic time (22.9 vs 0 min, p < 0.001), more blood loss (92.6 vs 161.9 ml, p = 0.02), and lower short-term renal function reduction of the operated kidney (17.2% vs 9%; p < 0.001). Neither major complication nor recurrence occurred.

CONCLUSION

It seems that transperitoneal laparoscopic off-clamp tumor evacuation is a feasible and safe option for the treatment of RAML, with the added benefit of preserving renal function to a greater extent than the traditional methods.

Off-clamp Versus On-clamp Robot-assisted Partial Nephrectomy: A Systematic Review and Quantitative Synthesis by the European Association of Urology Young Academic Urologists Renal Cancer Study Group

Context

The superiority of off-clamp robot-assisted partial nephrectomy (RAPN) over the on-clamp technique has recently been questioned by randomized controlled trials comparing the two techniques.

Objective

To systematically review the recent literature and perform a quantitative synthesis of data on the comparison of off-clamp versus off-clamp hilar control during RAPN.

Evidence acquisition

A systematic search was performed in the PubMed, Embase, Web of Science, and Scopus databases for studies comparing off-clamp versus on-clamp RAPN in terms of perioperative and functional outcomes. The study protocol was registered in the PROSPERO database (CRD42023413160). Only prospective randomized controlled trials and retrospective matched observational studies were included. The primary outcome of the study was the percentage decrease in the estimated glomerular filtration rate (eGFR).

Evidence synthesis

A total of 11 studies were included involving a total of 2483 patients (944 patients in the off-clamp and 1539 patients in the on-clamp group). There was no difference between the two groups in the percentage decline in eGFR (mean difference [MD] 0.04%, 95% confidence interval [CI] -3.7% to 3.86%; p = 0.98). There were so significant differences between the groups for length of hospital stay (p = 0.56), complications (p = 0.08), conversion to open or radical surgery (p = 0.18), estimated blood loss (p = 0.06), or need for blood transfusion (p = 0.07). The operative time was shorter in the off-clamp group (MD-21.89 min, 95% CI -42.5 to -1.27; p = 0.04) but after sensitivity analysis the difference was no longer statistically significant (p = 0.15). The positive surgical margin rate was significantly lower in the off-clamp group (odds ratio 0.6, 95% CI 0.39-0.91; p = 0.02).

Conclusions

Our review revealed no clinically relevant differences in perioperative and functional outcomes between off-clamp and on-clamp RAPN.

Patient summary

In this review, we compared the two methods of controlling the kidney blood vessels during robot-assisted surgery to remove part of the kidney. We noted that there was no difference between the two groups for outcomes such as complications and the decrease in kidney function after surgery.

The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial

PURPOSE

To evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN).

METHODS

The CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF). The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression.

RESULTS

324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR - 3.7 vs - 7.5 ml/min (p < 0.001); AV-SRF - 1% vs - 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] - 0.52, p = 0.019), age (RC - 0.35, p = 0.001) and baseline eGFR (RC - 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC - 0.30, p = 0.018), baseline SRF (RC - 0.76, p < 0.001) and RENAL score (RC - 0.60. p = 0.028). The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered.

CONCLUSIONS

Up to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

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.

Assessment of surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy for ≥T1b renal tumours

PURPOSE

To assess the surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy. In the era of robot-assisted surgeries, open partial nephrectomy remains a surgical option for  ≥ T1b renal tumours. Although the necessity of renal pedicle clamping and renorrhaphy in open partial nephrectomy for larger tumours remains to be discussed, reports on this issue are rare.

METHODS

Twenty-seven open partial nephrectomies for  ≥ T1b renal tumours were performed without renal pedicle clamping or renorrhaphy. A soft coagulation system was used to control bleeding from the resection bed. Surgical results, complications, and predictors of perioperative estimated glomerular filtration rate (eGFR) preservation at 1 month and 3 months after surgery were analysed.

RESULTS

The median estimated volume of blood loss was 420 mL. The rates of perioperative eGFR preservation were 88.9 and 87.3% at 1 and 3 months after surgery, respectively. Tumour size was an independent predictor of perioperative eGFR preservation at 1 month after surgery, whereas age and exophytic/endophytic properties of the tumour were independent predictors of perioperative eGFR preservation at 3 months after surgery.

CONCLUSION

Open partial nephrectomy without renal pedicle clamping or renorrhaphy could be safely performed for  ≥ T1b renal tumours, even when tumours were entirely endophytic and located close to the renal pedicle. Mild perioperative eGFR reduction was observed. Although surgical indications should be carefully considered in these cases, off-clamp open partial nephrectomy without renorrhaphy is a feasible procedure for patients with  ≥ T1b renal tumours.

Off-clamp Retroperitoneoscopic Tumour Evacuation for Sporadic Renal Angiomyolipomas with High RENAL Nephrometry Scores: A Novel Surgical Technique and Its Outcomes

BACKGROUND

Partial nephrectomy or angioembolisation is commonly used for sporadic renal angiomyolipomas (RAMLs) with high RENAL scores, but there is a risk of reduced renal function, postoperative complications, and recurrence.

OBJECTIVE

To describe a new technique for off-clamp laparoscopic evacuation of sporadic RAMLs with high RENAL scores that promotes maximal renal function maintenance and low postoperative complication and lesion recurrence rates.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort of patients undergoing off-clamp laparoscopic evacuation for sporadic RAMLs with RENAL scores ≥9 from January 2013 to June 2018 was included.

SURGICAL PROCEDURE

We highlighted the curettage, suction, packing, and binding (CSPB) technique, a new off-clamp retroperitoneoscopic evacuation technique for sporadic RAMLs.

MEASUREMENTS

Demographics, preoperative, intraoperative, and postoperative outcomes were assessed.

RESULTS AND LIMITATIONS

A total of 141 cases were included. The median (interquartile range [IQR]) tumour size was 7 (6.2-8.2)cm. The median (IQR) RENAL score was 10 (9-11). The median (IQR) operative time was 80 (65-125) min, with a median (IQR) estimated blood loss of 130 (90-362.5)ml. Conversion to neither open surgery nor standard laparoscopy occurred. The warm ischaemia time was zero for all cases. Postoperatively, 13 minor complications (Clavien grade 1) were recorded. No blood transfusions were reported. The glomerular filtration rate did not change significantly from preoperative period to 12-mo follow-up. Recurrence did not occur at the median follow-up period of 48 (36-60) mo. The retrospective design and lack of a control group are limitations of this study.

CONCLUSIONS

Off-clamp retroperitoneoscopic tumour evacuation using the CSPB technique is feasible, safe, and effective for treating complex sporadic RAMLs.

PATIENT SUMMARY

We report a curettage, suction, packing, and binding technique for off-clamp retroperitoneoscopic evacuation of sporadic renal angiomyolipomas that leads to complete lesion clearance, excellent renal function preservation, and minimal perioperative complications.

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.

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 role of RENAL, PADUA and C-index scoring systems in predicting the results of partial nephrectomy without ischemia

OBJECTIVE

To evaluate the feasibility and renoprotective effect of off-clamp partial nephrectomy (PN) by renal scoring systems.

METHODS

After approval of the local ethics committee, the radiological and clinical data of patients with renal masses who underwent PN between January 2012 and January 2017 were evaluated in two university hospitals. Total 132 patients who underwent open surgery and off-clamp technique were included. All patients underwent contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) preoperatively. Preoperative demographic data, estimated glomerular filtration rate (e-GFR) and hematocrit changes, operation time, tumor volume and hospitalization time from patients were evaluated separately and statistically for each of the three scoring systems.

RESULTS

Our study consisted of 132 patients with a mean age of 53.9 ± 13.9 with 69 male and 63 female. Statistically significant difference between the risk groups in RENAL and PADUA scoring were found according to tumor T stage and tumor volüme (p <0.005). Statistically significant difference was only found between risk groups of RENAL scoring system in e-GFR reduction (p<0.05). There was no statistically significant difference between the groups in the complications of all three classification systems (p > 0.005).

CONCLUSIONS

In our study, all three scoring sytem successfully predicted the surgical complexity ve surgical outcomes and our results indicate that off-clamp PN has similar success and complications rates when compared to the literature. The off-clamp PN must be kept in mind to maintain postoperative renal functions eligible patients.

Off-clamp partial nephrectomy has a positive impact on short- and long-term renal function: a systematic review and meta-analysis

Background

Ongoing efforts are focused on shortening ischemia intervals as much as possible during partial nephrectomy to preserve renal function. Off-clamp partial nephrectomy (off-PN) has been a common strategy for to avoid ischemia in small renal tumors. Although studies comparing the advantages between off-PN with conventional on-clamp partial nephrectomy (on-PN) have been reported, the impact on short- and especially long-term renal function of the two surgical methods has not been discussed seriously and remained unclear. Our purpose is to evaluate the impact on short- (within postoperative 3 months) and long-term (postoperative 6 months or longer) renal function of off-PN compared with that of on-PN.

Methods

We comprehensively searched databases, including PubMed, EMBASE, and the Cochrane Library, without restrictions on language or region. A systematic review and cumulative meta-analysis of the included studies were performed to assess the impact of the two techniques on short- and long-term renal function.

Results

A total of 23 retrospective studies and 2 prospective cohort studies were included. The pooled postoperative short-term decrease of estimated glomerular filtration rate (eGFR) was significantly less in the off-PN group (weighted mean difference [WMD]: 4.81 ml/min/1.73 m²; 95% confidence interval [CI]: 3.53 to 6.08; p < 0.00001). The short-term increase in creatinine (Cr) level in the on-PN group was also significant (WMD: − 0.05 mg/dl; 95%CI: − 0.09 to − 0.00; p = 0.04). Significant differences between groups was observed for the long-term change and percent (%) change of eGFR (p = 0.04 and p < 0.00001, respectively) but not for long-term Cr change (p = 0.40). The postoperative short-term eGFR and Cr levels, but not the postoperative long-term eGFR, differed significantly between the two groups. The pooled odds ratios for acute renal failure and postoperative progress to chronic kidney disease (stage≥3) in the off-PN group were found to be 0.25 (p = 0.003) and 0.73 (p = 0.34), respectively, compared with the on-PN group.

Conclusions

Off-PN exerts a positive impact on the short- and long-term renal function compared with conventional on-PN. Given the inherent limitations of our included studies, large-volume and well-designed RCTS with extensive follow up are needed to confirm and update the conclusion of this analysis.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0993-3) contains supplementary material, which is available to authorized users.

Off-Clamp Renal Tumourectomy by Retroperitoneoscopy in Posterior Renal Tumours of Medium Complexity (Padua score 8-9)

BACKGROUND

The guidelines recommend partial surgery for T1 renal tumours. Various aspects of this surgery have evolved in recent years, including the clamping method and duration, enucleation, the retroperitoneoscopic approach and the use of 3mm ports. We present our initial series on laparoscopic renal tumourectomy by retroperitoneoscopy (LRTR) and analyse our learning curve and use of 3-mm instrumentation.

MATERIAL AND METHODS

From January 2011 to January 2015, we performed LRTR on 50 patients with posterior or convex T1 renal tumours. After 10 cases, the technique changed to off-clamp, and 11 cases were subsequently performed with 3mm instrumentation.

RESULTS

The mean tumour size was 34.36 mm (14-62), with a mean PADUA score of 8.42 (5-12). The mean operative time was 163.1 minutes (75-300), and the mean warm ischaemia time was 4.21 minutes (0-28). The main renal artery was not clamped in 41 (82%) patients, and no vessel (zero ischaemia) was clamped in 39 (78%) patients. Seven cases had positive margins (6 focal). Eleven LRTRs were performed with 3mm instrumentation, with shorter surgical times, less intraoperative bleeding and shorter hospital stays.

CONCLUSIONS

Retroperitoneoscopy coupled with enucleation enables the extirpation without clamping of posterior renal tumours, with a relatively short learning curve. The 3-mm material enables the technique to be performed, although in our experience it has resulted in a higher rate of positive surgical margins.