Outcomes of robot-assisted simple enucleation of renal masses: A single European center experience

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.

Robot-assisted Partial Nephrectomy: 5-yr Oncological Outcomes at a Single European Tertiary Cancer Center

BACKGROUND

Nowadays, there is a debate about which surgical treatment should be best for clinical T1 renal tumors. If the oncological outcomes are considered, there are many open and laparoscopic series published. As far as robotic series are concerned, only a few of them report 5-yr oncological outcomes.

OBJECTIVE

The aim of this study was to analyze robot-assisted partial nephrectomy (RAPN) midterm oncological outcomes achieved in a tertiary robotic reference center.

DESIGN, SETTING, AND PARTICIPANTS

Between April 2009 and September 2013, 123 consecutive patients with clinical T1-stage renal masses underwent RAPN in our tertiary cancer center. Inclusion criteria were as follows: pathologically confirmed renal cell carcinomas (RCCs) and follow-up for >12 mo. Eighteen patients were excluded due to follow-up of <12 mo and 15 due to benign final pathology. Median follow-up was 59 mo (interquartile range 44-73 mo). Patients were followed according to guideline recommendations and institutional protocol.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcomes were measured by time to disease progression, overall survival, or time to cancer-specific death. Kaplan-Meier method was used to estimate survival; log-rank tests were applied for pair-wise comparison of survival.

RESULTS AND LIMITATIONS

From the 90 patients included, 66 (73.3%) had T1a, 12 (13.3%) T1b, three (3.3%) T2a, and nine (10%) T3a tumors. Predominant histological type was clear cell carcinoma: 67 (74.5%). Fuhrmann grade 1 and 2 was found in 73.3% of all malignant tumors. Two patients (2.2%) had positive surgical margins, and complication rate was 17.8%. Relapse rate was 7.7%, including two cases (2.2%) of local recurrences and five (5.5%) distant metastasis. Five-year disease-free survival was 90.9%, 5-yr cancer-specific survival was 97.5%, and 5-yr overall survival was 95.1%.

CONCLUSIONS

Midterm oncological outcomes after RAPN for localized RCCs (predominantly T1a tumors of low anatomic complexity) were shown to be good, adding significant evidence to support the oncological efficacy and safety of RAPN for the treatment of this type of tumors.

PATIENT SUMMARY

Robot-assisted partial nephrectomy seems to be the most promising minimally invasive approach in the treatment of renal masses suitable for organ-sparing surgery as midterm (5 yr) oncological outcomes are excellent.