Robotic-assisted tumor enucleation versus robotic-assisted partial nephrectomy for intermediate and high complexity renal cell carcinoma: a single-institution experience

OBJECTIVES

To compare the perioperative and oncological outcomes of robotic-assisted tumor enucleation (RATE) and robotic-assisted partial nephrectomy (RAPN) in the treatment of intermediate and high complexity renal cell carcinoma (RCC).

METHODS

We retrospectively collected the data of 359 patients with intermediate and high complexity RCC who underwent RATE and RAPN. The perioperative, oncological, and pathological outcomes of the two groups were compared, and univariate and multivariate analyses were used to evaluate the risk factors for warm ischemia time (WIT) > 25 min.

RESULTS

Compared with RAPN group, patients in RATE group had shorter operative time (P < 0.001), shorter WIT (P < 0.001), and less estimated blood loss (EBL) (P < 0.001). The decrease rate of estimated glomerular filtration rate (eGFR) in RATE group was better than that in RAPN group (P < 0.001). Multivariable analysis showed that RAPN and higher PADUA score were independent risk factors for WIT > 25 min (both P < 0.001). The rate of positive surgical margin was similar between the two groups, but the local recurrence rate of the RATE group was higher than that of the RAPN group (P = 0.027).

CONCLUSIONS

RATE and RAPN have similar oncological outcomes for the treatment of intermediate and high complexity RCC. In addition, RATE was superior to RAPN in perioperative outcomes.

A prospective, multicenter analysis of pseudocapsule characteristics: Do all stages of renal cell carcinoma have complete pseudocapsules?

OBJECTIVES

To assess the characteristics of pseudocapsule (PC) in localized renal cell carcinoma (RCC) by analyzing the rates of completeness of PC and pseudocapsular invasion and clinical and pathological risk factors of it.

MATERIALS AND METHODS

Between February 2013 and September 2015, data were gathered prospectively from 180 consecutive patients who underwent partial nephrectomy or radical nephrectomy at 3 institutions, and 161 were enrolled. Evaluated factors included age and sex; histologic factors such as tumor diameter, stage, tumor subtype, necrosis, and Fuhrman grade; and clinical factors such as RENAL score; and completeness of PC.

RESULTS

Only 94 tumors (58.4%) were surrounded by a continuous PC completely, 62 (38.5%) were partially surrounded, and 5 (3.1%) had no PC. Overall, 56 PCs (34.8%) were free from invasion, 58 PCs (36.0%) had partial invasion of PC without parenchymal invasion, and 47 PCs (29.2%) had parenchymal invasion. Defining parenchymal invasion as true pseudocapsular invasion, histologic diameter, RCC subtype, and completeness of PC were significant predictors for parenchymal invasion on multivariate analysis (P = 0.006, 0.046, and 0.002, respectively).

CONCLUSIONS

Rate of complete PC in RCC is relatively low in this study. The risk factors for pseudocapsular invasion were a histologic diameter greater than 4cm, non-clear cell histology, and an incomplete PC. Surgeons must prepare for the possibility of a positive surgical margin if a tumor has at least one of these risk factors.

Impact of ischaemia time on renal function after partial nephrectomy: a systematic review

OBJECTIVE

To assess the impact of ischaemia on renal function after partial nephrectomy (PN).

MATERIALS AND METHODS

A literature review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. In January 2015, the Medline and Embase databases were systematically searched using the protocol ('warm ischemia'[mesh] OR 'warm ischemia'[ti]) AND ('nephrectomy'[mesh] OR 'partial nephrectomy'[ti]). An updated search was performed in December 2015. Only studies based on a solitary kidney model or on a two-kidney model but with assessment of split renal function were included in this review.

RESULTS

Of the 1119 studies identified, 969 abstracts were screened after duplicates were removed: 29 articles were finally included in this review, including nine studies that focused on patients with a solitary kidney. None of the nine studies adjusting for the amount of preserved parenchyma found a negative impact of warm ischaemia time on postoperative renal function, unless this was extended beyond a 25-min threshold. The quality and the quantity of preserved parenchyma appeared to be the main contributors to postoperative renal function.

CONCLUSION

Currently, no evidence supports that limited ischaemia time (i.e. ≤25 min) has a higher risk of reducing renal function after PN compared to a 'zero ischaemia' technique. Several recent studies have suggested that prolonged warm ischaemia (>25-30 min) could cause an irreversible ischaemic insult to the surgically treated kidney.

Tumor enucleation vs sharp excision in minimally invasive partial nephrectomy: technical benefit without impact on functional or oncologic outcomes

OBJECTIVE

To present the benefits and utility of tumor enucleation as an alternative technique to sharp excision during minimally invasive partial nephrectomy (MIPN).

METHODS

We retrospectively compared enucleation and sharp excision during MIPN, with the aim of determining benefits and limitations of enucleation in this setting.

RESULTS

Among 602 patients undergoing MIPN at our institution, 86 and 516 underwent enucleation and sharp excision, respectively, as determined by the surgeon. The nephrometry score was greater in the enucleation vs sharp excision group (mean, 6.7 vs 6.3), but all other preoperative parameters were similar. The mean ischemia and operative times were 4 and 32 minutes shorter in the enucleation group, respectively, likely owing to less frequent entry into renal sinus (21% vs 41%) and need for tumor bed suturing (41% vs 62%), compared with those in the sharp excision group. There was no association with blood loss, positive margins, urine leak, blood transfusion, major complications, renal function, recurrence, or survival.

CONCLUSION

Enucleation appears to provide the benefits of reduced surgical entry into the renal sinus, less need for tumor bed suturing, and shorter operative time, without any impact on functional or oncologic outcomes. Given favorable preoperative radiography and intraoperative findings, enucleation is a useful technique for patients undergoing MIPN.

Analysis of surgical complications of renal tumor enucleation with standardized instruments and external validation of PADUA classification

PURPOSE

To assess surgical results and morbidity of tumor enucleation (TE), and to evaluate their correlation with PADUA nephrometric score.

METHODS

We prospectively gathered data, including accurate analysis of tumor nephrometry, from 244 consecutive patients treated with TE for clinically localized renal cell carcinoma. All surgical results were collected, and perioperative complications were stratified for severity according to Clavien system. Correlation between preoperative variables and surgical results/complications was assessed with uni- and multivariate analysis.

RESULTS

Mean (range) tumor size was 3.6 (0.8-10.0) cm, and mean (range) warm ischemia time was 16.8 (5-35) min. Overall, perioperative complications occurred in 45 patients (18.4 %), and of those 8 were medical and 37 were surgical (4 Clavien grade 1, 25 grade 2, and 8 grade 3) complications. Urine leakage rate was 2.0 %. No grade 4/5 complications occurred in this series. At univariate analysis PADUA score, endophytic tumor growth, tumor diameter, involvement of UCS and renal sinus resulted associated with warm ischemia time (p < 0.0001 each) and surgical complications (p = 0.0007, p = 0.049, p = 0.021, p = 0.036, and p = 0.029, respectively). At logistic regression, nephrometry score resulted independently associated with overall complications (related risk for each increased point 1.54; p = 0.017), surgical complications (related risk 1.58; p = 0.016), and Clavien grade 3 surgical complications (related risk 2.99; p = 0.008).

CONCLUSIONS

The TE technique was associated with a 15.2 % surgical complication rate with a 3.3 % reintervention rate (including ureteral stenting and superselective renal artery embolization). Tumor nephrometry and surgical indication resulted independent predictors of Clavien grade 3 complications. The PADUA score is a reliable tool to predict surgical results and morbidity of TE.