Impact of preoperative calculation of nephron volume loss on future of partial nephrectomy techniques; planning a strategic roadmap for improving functional preservation and securing oncological safety.

OBJECTIVES: To assess the correlation of the resected and ischaemic volume (RAIV), which is a preoperatively calculated volume of nephron loss, with the amount of postoperative renal function (PRF) decline after minimally invasive partial nephrectomy (PN) in a multi-institutional dataset. PATIENTS AND METHODS: We identified 348 patients from March 2005 to December 2013 at six institutions. Data on all cases of laparoscopic (n = 85) and robot-assisted PN (n = 263) performed were retrospectively gathered. Univariable and multivariable linear regression analyses were used to identify the associations between various time points of PRF and the RAIV, as a continuous variable. RESULTS: The mean (sd) RAIV was 24.2 (29.2) cm3 . The mean preoperative estimated glomerular filtration rate (eGFR) and the eGFRs at postoperative day 1, 6 and 36 months after PN were 91.0 and 76.8, 80.2 and 87.7 mL/min/1.73 m2 , respectively. In multivariable linear regression analysis, the amount of decline in PRF at follow-up was significantly correlated with the RAIV (ß 0.261, 0.165, 0.260 at postoperative day 1, 6 and 36 months after PN, respectively). This study has the limitation of its retrospective nature. CONCLUSION: Preoperatively calculated RAIV significantly correlates with the amount of decline in PRF during long-term follow-up. The RAIV could lead our research to the level of prediction of the amount of PRF decline after PN and thus would be appropriate for assessing the technical advantages of emerging techniques.

Robotic laparoendoscopic single-site transumbilical partial nephrectomy: functional and oncologic outcomes at 2 years.

OBJECTIVE: To assess the functional and oncologic outcomes of robotic laparoendoscopic single site surgery (LESS) partial nephrectomy with a minimum of 2-year follow-up. MATERIALS AND METHODS: Thirty-nine consecutive patients who had undergone robotic LESS partial nephrectomy were identified with a minimum of 2-year follow-up. Perioperative data were recorded along with functional and oncologic outcomes. Patient's estimated glomerular filtration rate was determined using the Modification of Diet in Renal Disease formula. A univariate analysis was performed using independent samples t test. Data are presented as medians with interquartile range and counts or frequencies with percentages or proportion. RESULTS: The median age was 51 (45, 59). The median resected tumor size was 3 cm (2, 3.7), and the median operative time was 185 minutes (135, 237). The median estimated blood loss was 150 mL (70, 150), and the median warm ischemia time was 25 minutes (17, 35). The estimated glomerular filtration rate did not change significantly at 24 month follow-up with a mean decrease of 6.4 mL/minute/1.73 m(2) (-7.5%, P = .22). Renal cell carcinoma was confirmed in 33 patients (85%) with tumor stage pT1a in 26 patients (78%). There was 1 patient with a positive surgical margin. At a median follow-up of 26 months (24, 32), there was no local recurrence and only 1 distant recurrence was detected. CONCLUSION: This study appears to be the first to report on intermediate term functional and oncologic outcomes after robotic LESS partial nephrectomy. It has shown comparable results with other minimal invasive surgical options.

Feasibility of robotic laparoendoscopic single-site partial nephrectomy for renal tumors >4 cm.

BACKGROUND: Laparoendoscopic single-site (LESS) urologic procedures have gained significant interest worldwide in an attempt to further reduce morbidity and minimize scarring associated with conventional laparoscopic surgery. The robotic technology has overcome some of the limitations of manual single-incision surgery relating to lack of triangulation, instrument collision, and surgical exposure. There are no data on robotic LESS partial nephrectomy (PN) for renal tumors >4 cm. OBJECTIVES: To evaluate the feasibility of robotic LESS PN for renal tumors >4 cm. DESIGN, SETTING, AND PARTICIPANTS: Data from 67 consecutive patients who underwent robotic LESS PN were collected between May 2009 to January 2011. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients were stratified into two groups: 20 patients with renal tumors >4 cm (group 1) and 47 patients with renal tumors ≤ 4 cm (group 2). Perioperative data were recorded and comparisons between the two groups were analyzed using the Mann-Whitney U test for continuous variables and Fisher exact test for categorical variables. RESULTS AND LIMITATIONS: No statistically significant differences were found between the two groups in demographic information, operative complications, pathologic characteristics, mean decline in estimated glomerular filtration rate, estimated blood loss, operative times, conversion rate, or positive surgical margins. However, group 1 had a higher mean nephrometry score (p<0.01), longer warm ischemia time (p = 0.007), and longer length of stay (p = 0.046). Its retrospective design and being conducted at a single center were the main limitations of this study. CONCLUSIONS: This study demonstrated the feasibility and safety of robotic LESS PN for tumors >4 cm. Patients with tumors >4 cm had a statistically significant, higher mean nephrometry score, longer warm ischemia time, and longer length of stay, but there was no increased risk of adverse outcomes. A long-term study is needed to confirm the durable renal preservation and oncologic outcomes for patients with larger tumor burden.