DOES THE SIZE OF THE SURGICAL MARGIN IN PARTIAL NEPHRECTOMY FOR RENAL CELL CANCER REALLY MATTER?

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.

Outcomes and Techniques of Robotic-Assisted Partial Nephrectomy (RAPN) for Renal Hilar Masses: A Comprehensive Systematic Review

Background: Robot-assisted partial nephrectomy (RAPN) is increasingly being employed in the management of renal cell carcinoma (RCC) and it is expanding in the field of complex renal tumors. The aim of this systematic review was to consolidate and assess the results of RAPN when dealing with entirely central hilar masses and to examine the various methods used to address the surgical difficulties associated with them. Methods: A thorough literature search in September 2023 across various databases focused on RAPN for renal hilar masses, adhering to PRISMA guidelines. The primary goal was to evaluate RAPN's surgical and functional outcomes, with a secondary aim of examining different surgical techniques. Out of 1250 records, 13 full-text manuscripts were reviewed. Results: Evidence is growing in favor of RAPN for renal hilar masses. Despite a predominance of retrospective studies and a lack of long-term data, RAPN shows positive surgical outcomes and preserves renal function without compromising cancer treatment effectiveness. Innovative suturing and clamping methods are emerging in surgical management. Conclusions: RAPN is a promising technique for managing renal hilar masses in RCC, offering effective surgical outcomes and renal function preservation. The study highlights the need for more long-term data and prospective studies to further validate these findings.

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.

Resection Techniques During Robotic Partial Nephrectomy: A Systematic Review

Context

The resection technique used to excise tumor during robotic partial nephrectomy (RPN) is of paramount importance in achieving optimal clinical outcomes.

Objective

To provide an overview of the different resection techniques used during RPN, and a pooled analysis of comparative studies.

Evidence acquisition

The systematic review was conducted according to established principles (PROSPERO: CRD42022371640) on November 7, 2022. A population (P: adult patients undergoing RPN), intervention (I: enucleation), comparator (C: enucleoresection or wedge resection), outcome (O: outcome measurements of interest), and study design (S) framework was prespecified to assess study eligibility. Studies reporting a detailed description of resection techniques and/or evaluating the impact of resection technique on outcomes of surgery were included.

Evidence synthesis

Resection techniques used during RPN can be broadly classified as resection (non-anatomic) or enucleation (anatomic). A standardized definition for these is lacking. Out of 20 studies retrieved, nine compared "standard" resection versus enucleation. A pooled analysis did not reveal significant differences in terms of operative time, ischemia time, blood loss, transfusions, or positive margins. Significant differences favoring enucleation were found for clamping management (odds ratio [OR] for renal artery clamping 3.51, 95% confidence interval [CI] 1.13-10.88; p = 0.03), overall complications (OR for occurrence 0.55, 95% CI 0.34-0.87; p = 0.01) major complications (OR for occurrence 0.39, 95% CI 0.19-0.79; p = 0.009), length of stay (weighted mean difference [WMD] -0.72 d, 95% CI -0.99 to -0.45; p < 0.001), and decrease in estimated glomerular filtration rate (WMD -2.64 ml/min, 95% CI -5.15 to -0.12; p = 0.04).

Conclusions

There is heterogeneity in the reporting of resection techniques used during RPN. The urological community must improve the quality of reporting and research produced accordingly. Positive margins are not specifically related to the resection technique. Focusing on studies comparing standard resection versus enucleation, advantages with tumor enucleation in terms of avoidance of artery clamping, overall/major complications, length of stay, and renal function were found. These data should be considered when planning the RPN resection strategy.

Patient summary

We reviewed studies on robotic surgery for partial kidney removal using different techniques to cut away the kidney tumor. We found that a technique called "enucleation" was associated with similar cancer control outcomes in comparison to the standard technique and had fewer complications, better kidney function after surgery, and a shorter hospital stay.

Evaluation of the safety of retroperitoneal laparoscopic partial nephrectomy by investigating the perioperative indicators

Background

In recent years, open nephron sparing partial nephrectomy (OPN) has been gradually applied and generally accepted. Recent statistical data show that PN not only can safely and effectively preserve the functional nephron, but also has fewer complications, low local recurrence rate and no significant difference in long-term survival rate compared with nephrectomy/radical nephrectomy, which has gradually become a routine treatment for small renal cell carcinoma. Therefore, how to maximize the protection of postoperative residual renal function (RRF) and reduce the risk of CKD while achieving the ideal local and overall tumor control effect is the key to the treatment of renal cancer, and is also the focus of attention of urologists and nephrologists.

Objective

To evaluate the safety of retroperitoneal laparoscopic partial nephrectomy (RLPN) by investigating the perioperative indicators and postoperative follow-up.

Methods

A total of 40 hospitalized patients in our hospital from December 2019 to December 2021 were selected and followed up for a long time. Patients with renal tumors less than 4cm in diameter and exogeneous or partial exogeneity were randomly divided into 2 groups. Patients in retroperitoneal laparoscopic group (n = 20) were treated with nephron sparing partial nephrectomy (0.5-1cm). Twenty patients underwent retroperitoneal laparoscopic radical nephrectomy (LRN).The time of removal of drainage tube, drainage volume, time of feeding activity and postoperative hospital stay were recorded, and the safety of the operation was evaluated.

Results

nephron sparing partial nephrectomy is suitable for patients with localized renal carcinoma or benign tumor <4cm. RLPN can be applied to all indications of open nephron sparing partial nephrectomy (OPN), with good safety, and can preserve residual renal function to the greatest extent. The operative vascular occlusion time was controlled within 40 minutes, and the use of renal function protection measures during the operation was safe and controllable in reducing the prevention of warm ischemic kidney damage, with good safety. The renal tumor capsule with 0.5cm~1cm margin was complete by postoperative pathology. In the process of tumor resection and suture collection system in the RLPN group, we improved the previous operation of "resection before hemostasis" to "resection while hemostasis" and "knot-free suture" technology, which saved the operation time of intracavity suture knotting. Reduced cortical tear caused by vertical pull during knot tying. The combined effect of biological clip and hemostatic gauze can stimulate the granulation proliferation of renal cortical wound and accelerate the repair. With the combination of knot-free suture and renal segment vascular occlusion, hot ischemic kidney damage is reduced. In the RLPN group, there were no complications of urinary fistula and bleeding, and no abnormal changes in renal function during follow-up. The safety of RLPN group is worthy of affirmation.

Conclusion

The perioperative safety and short-term postoperative renal function recovery of RLPN are good, and the overall safety of this operation is worthy of affirmation.

Positive surgical margins may not affect the survival of patients with renal cell carcinoma after partial nephrectomy: A meta-analysis based on 39 studies

Background

So far, whether positive surgical margin(PSM) has adverse effects on the prognosis of patients is still controversial, so we designed this study to systematically evaluate the effect of PSM on the prognosis of patients with renal cell carcinoma (RCC) after partial nephrectomy (PN).

Methods

On the basis of three electronic databases (PubMed, Embase and the Cochrane Library) up to May 2022, all case-control studies (CCSs) comparing the effects of PSM and negative surgical margin (NSM) after PN on the oncological results of RCC patients were included. Two evaluators independently conducted a systematic literature search and extracted the data we needed. The methodological quality of all studies was evaluated by the modified Newcastle-Ottawa scale. The odds ratio (OR) was used to describe the results for dichotomous variables, and the meta-analysis was conducted using Cochrane Review Manager 5.2 and Stata 14.2.

Results

A total of 39 studies involving 21461 patients were included in our meta-analysis. The pooled results showed that the rates of tumor recurrence (OR 3.93, 95% CI 2.95-5.24; p < 0.00001) and metastasis (OR 4.63, 95% CI 3.11-6.88; p < 0.00001) in the PSM group were significantly higher than those in the NSM group. However, there were no significant differences in the rates of all-cause death (OR 1.35, 95% CI 0.92-1.99; p = 0.13) or cancer-specific death (OR 0.99, 95% CI 0.51-1.94; p = 0.99) between the two groups. In addition, subgroup analyses were carried out according to different average follow-ups, which revealed similar results.

Conclusion

Insignificant differences in survival between the PSM and NSM groups were observed, although significant differences in recurrence and metastasis in the PSM group were reported. Our study supported that close monitoring might be another effective choice for patients with PSM after PN. Considering the possible limitations, we recommended cautious interpretation of our results.

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.

Is there a clinical role for frozen section analysis during partial nephrectomy? A multicenter experience over 10 years

BACKGROUND

Frozen section analysis (FSA) is frequently performed during partial nephrectomy (PN). We investigate the utility of intraoperative FSA by evaluating its impact on final surgical margin (SM) status.

METHODS

Between January 1995 and December 2005, a series of patients who were treated with open PN for renal cell carcinoma was prospectively analyzed. During PN, each patient underwent a FSA on renal parenchyma distal margin. If FSA was positive for infiltration a deeper excision was performed till obtaining a negative FSA. SM outcome of the FSA was compared with the final pathology report. Recurrence-free survival (RFS) and cost analysis on the FSA performed were analyzed.

RESULTS

A total number of 373 patients were enrolled. FSA was performed in all the patients considered for PN. Fifteen patients had a conversion to radical nephrectomy. Positive SMs at the definitive pathological outcome were found in 36 patients (9.6%). FSA was positive in eight patients (2.1%). In that eight cases after a deeper excision the definitive pathological outcome on SM was still positive in two cases. FSA revealed just 14.3% of the positive SM. Patients with positive SM had a worse follow up considering RFS (P<0.05). Kaplan-Meier analysis revealed that FSA did not considerably contribute to prevent recurrence (P=0.35). 1438 euros was the mean cost of performing a FSA during PN.

CONCLUSIONS

FSA during PN does not reduce the risk of positive SMs. The use of FSA has also a higher cost related to the procedure.

The Correlation of Clinicopathological Features With the Status of Surgical Margins in Renal Cell Cancer Patients Following Nephron-Sparing Surgery: A Systematic Review and Meta-Analysis

Objectives: The aim of this study was to evaluate the correlation of various clinicopathological variables with positive surgical margins (PSMs) in renal cell cancer (RCC) patients after nephron-sparing surgery (NSS). Methods: A systematic search of PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) was performed to identify studies that compared PSMs with negative surgical margins (NSMs) and were published up to December 2018. Outcomes of interest included perioperative and postoperative variables, and the data were pooled by odds ratios (ORs)/standard mean differences (SMD) with 95% confidence intervals (CIs) to evaluate the strength of such associations. STATA 12.0 software was used for all statistical analyses. Results: Based on the inclusion and exclusion criteria, 13 studies including 47,499 patients with RCC were analyzed. The results showed that higher Furhman grade (pooled OR = 1.25; 95% CI: 1.14-1.37; P < 0.001), higher pathological stage (pooled OR = 2.67; 95% CI: 2.05-3.50; P < 0.001), non-clear cell RCC (non-ccRCC) histology (pooled OR = 0.78; 95% CI: 0.72-0.84; P < 0.001), and non-white race (pooled OR = 0.90; 95% CI: 0.82-0.99; P = 0.026) were significantly associated with high risk of PSMs. However, age (pooled SMD = 0.09; 95% CI: -0.01-0.20; P = 0.078), gender (female vs. male) (pooled OR = 1.04; 95% CI: 0.96-1.12; P = 0.377), tumor laterality (left vs. right) (pooled OR = 1.09; 95% CI: 0.84-1.42; P = 0.501), tumor focality (unifocal vs. multifocal) (pooled OR = 0.67; 95% CI: 0.23-1.90; P = 0.445), tumor size (pooled SMD = 0.03; 95% CI: -0.10-0.15; P = 0.685), and surgical approach (open vs. non-open) (pooled OR = 0.94; 95% CI: 0.62-1.42; P = 0.763) had no relationship with PSMs. Sensitivity analysis showed that all models were stable, and no publication bias was observed in our study. Conclusions: The present findings demonstrate that the presence of PSMs was associated with higher Furhman grade and higher pathological stage. Additionally, non-white patients with non-ccRCC histology had a high risk of PSMs after NSS. Further multicenter and long-term follow-up studies are required to verify these findings.

Clampless and sutureless laparoscopic partial nephrectomy using monopolar coagulation with or without N-butyl-2-cyanoacrylate

OBJECTIVE

To describe a novel technique for clampless and sutureless laparoscopic partial nephrectomy (LPN) using monopolar coagulation with or without N-butyl-2-cyanoacrylate (NBCA).

METHODS

From February 2015 to October 2018, we performed clampless and sutureless LPN using monopolar coagulation with or without NBCA on 142 patients. The tumors were resected with cold scissor. The tumor beds were repeatedly coagulated with a monopolar hook in spray and fulgurate modes. NBCA was sprayed when bleeding was observed after coagulation in 98 patients. We compared outcomes in the NBCA and non-NBCA groups.

RESULTS

Mean patient age was 55 years (range 20-86). Mean tumor size was 3.2 cm (range 1.0-10.6). Mean RENAL nephrometry score was 5 (range 4-8). Mean operative time was 120 min (range 40-200). Mean estimated blood loss was 100 ml (range 10-500). Mean eGFR changes were 2.3 ml/min. Two patients had positive surgical margins. Three patients received blood transfusions. No patients had urine leakage. Patients receiving NBCA had larger tumors (3.0 vs 2.0 cm, p < 0.001), higher RENAL nephrometry scores (5.59 vs 4.47, p = 0.004), and higher E item scores (p = 0.009).

CONCLUSIONS

Use of monopolar coagulation with NBCA in clampless and sutureless LPN for renal tumors with low RENAL nephrometry scores is safe and effective. For patients with exophytic renal tumors less than 2 cm, NBCA is not necessary.

Effect of histopathologic characteristics on pseudocapsular invasion in the case of partial nephrectomy for renal tumours

OBJECTIVE

It is aimed to define the existence of pseudocapsular structure on renal tumours, illuminate the relation between pseudocapsular invasion and Fuhrman grade histological type that are among histopathologic prognostic risk factors and determine the relation between surgical margin positivity and existence of pseudocapsular invasion. Sequential partial nephrectomy series and relevant pathological preparations were retrospectively reviewed in order to evaluate these issues.

METHODS

The study includes 123 patients diagnosed with T1 renal tumour and treated with partial nephrectomy in between January 2007 and June 2016. Benign angiomyolipoma was excluded due to complete non-existence of pseudocapsule. 99 T1 patients diagnosed with renal cell cancer whose pathological slides can be duly analysed were included in the study. Clinical and pathological details were evaluated for all patients. Existence of pseudocapsule was revealed for all patients. Pseudocapsule invasion was classified by existence of expansive and infiltrative type and non-existence of pseudocapsule invasion. The groups have been assessed by their histopathologic characteristics.

RESULTS

Compared to the group in which pseudocapsular invasion was not detected, clear-cell histological subtype was observed more frequently in a statistically significant way in the group with expansive pseudocapsular invasion and infiltrative pseudocapsular invasion respectively (p = 0.017 and p < 0.001). Pathological tumour sizes were found out to be statistically similar (p = 0.874). There was not a statistically significant difference in terms of Fuhrman grade (p = 0.220). There was not a statistically significant difference in terms of surgical positive margin (p = 0.609).

CONCLUSION

It was indicated in our study that only the histological subtype affected pseudocapsular invasion in group of patients treated with partial nephrectomy but tumour size, tumour stage, tumour location as well as endophytic and exophytic character did not affect invasion. It has also been revealed that surgical margin positivity is not correlated with pseudocapsular invasion.

DDD score for renal tumor: An intuitive and comprehensive anatomical scoring system to access the outcomes of retroperitoneal laparoscopic partial nephrectomy

OBJECTIVE

To present a DDD scoring system in assessing the complexity and outcomes of retroperitoneoscopic nephron-sparing surgery for kidney tumor.

METHODS

We retrospectively evaluated 232 patients who underwent retroperitoneoscopic nephron-sparing surgery between January 2013 and September 2017 for a renal tumor. Both the DDD score and RENAL score were used to classify the tumors. The DDD score consisted of the maximal tumor diameter inside the kidney, the maximal tumor depth into the medulla or collecting system and the minimal distance from the tumor to the main renal vessels.

RESULTS

The DDD scoring systems were significantly associated with warm ischemia time (P = 0.007) and estimated blood loss (P = 0.017). There was an insignificant positive correlation between the DDD score and the operative time (P = 0.051). Meanwhile, the RENAL score had a significant correlation with the decreasing value of the estimated glomerular filtration rate. Patients with high or moderate DDD scores had a 13.6-fold or 8.4-fold risk of overall complications than those with low DDD scores, respectively (all P < 0.05). As for RENAL score, patients with moderate scores had a 2.9-fold risk of overall complications compared with patients in the low scores group (P = 0.004). In the receiver operating characteristic curve analysis, the DDD score had the greatest area under the curve for overall complications (area under the curve 0.625, P = 0.009), which was more than the RENAL score (area under the curve 0.620, P = 0.013).

CONCLUSIONS

The DDD score is an intuitive renal tumor scoring system that is more effective than the RENAL score in complexity assessment, and marginally better in prediction of the risk of overall complications of retroperitoneal laparoscopic nephron-sparing surgery.

Endoscopic Robot-assisted Simple Enucleation Versus Laparoscopic Simple Enucleation With Single-layer Renorrhaphy in Localized Renal Tumors: A Propensity Score-matched Analysis From a High-volume Centre

OBJECTIVE

To compare perioperative results and early oncological outcomes of endoscopic robot-assisted simple enucleation (ERASE) and laparoscopic simple enucleation (LSE) by using a propensity score-matched analysis.

METHODS

We evaluated 383 patients who underwent transperitoneal ERASE or LSE for renal tumors from November 2012 to October 2016. Propensity score matching was performed on age, gender, body mass index, Eastern Cooperative Oncology Group score, tumor side and size, preoperative estimated GFR and PADUA score.

RESULTS

In total, 278 and 105 patients underwent ERASE and LSE, respectively. The PADUA score was ≥10 for 61 (21.9%) and 13 (12.4%), respectively (P = .034). After matching, mean operative time and warm ischemic time were significantly lower with ERASE than LSE (171.9 vs 188.2 minutes; P = 0.016 and 20.9 vs 24.2 minutes; P = .001). The estimated mean blood loss was similar (167.7 vs 183.3 mL; P = .315). The conversion rate to open surgery or radical nephrectomy was similar with ERASE and LSE (1.0% vs 5.0%, P = .214) and the rate of intraoperative complications was lower (2.0% vs 8.9%, P = .030). The overall incidence of positive surgical margins was similar (P = .614). The median follow-up was less for ERASE than LSE patients (22 vs 38 months). Recurrence did not differ between the 2 groups: 2 ERASE cases (2.0%) versus 4 LSE cases (4.0%) (P = .679).

CONCLUSION

ERASE is a safe and acceptable alternative to LSE. ERASE appears to confer shorter operative time, shorter warm ischemic time and lower rate of intraoperative complication.

Does tumour effraction during robotic partial nephrectomy have any impact on recurrence?

OBJECTIVE

To evaluate the impact of accidental surgical incision into the tumour (ASIT) on oncological outcomes in patients undergoing RPN for a malignant tumour.

MATERIALS AND METHODS

A retrospective review of our prospectively maintained database was performed to identify all patients who underwent RPN for a localized RCC between June 2010 and July 2016. We stratified our cohort into two groups according to the presence of an ASIT. Perioperative data were compared between the two groups. Logistic regression analyses were used to assess the variables associated with ASIT. Recurrence-free survival was estimated using the Kaplan-Meier method and compared between groups with the log-rank test.

RESULTS

A total of 234 patients were identified. 32 (14%) ASIT were observed. Patients' characteristics were similar in the two groups. Most of intraoperative outcomes were comparable between the two groups, but patients in the ASIT group had greater EBL (475 vs. 300 mL; p = 0.01). In multivariate analysis, tumour size (p = 0.02), RENAL score (p = 0.02), EBL (p = 0.05) and low surgeon experience (p = 0.03) were all predictive factors of ASIT. 15 (6%) of recurrences were observed over a median follow-up of 36 months. There was no difference in recurrence-free survival between the two groups (p = 0.57).

CONCLUSIONS

In our experience, accidental surgical incision into the tumour during RPN was a common event that did not appear to compromise oncological outcome.

[Three-dimensional spatial measurement versus conventional CT planning in laparoscopic partial nephrectomy for renal tumors]

OBJECTIVE

To analyze the advantages of spatial measurement of anatomical parameters in a 3D model in surgical planning for laparoscopic partial nephrectomy (LPN).

METHODS

From February, 2016 to October, 2017, 37 patients diagnosed with T1 renal mass underwent LPN based on 3D reconstruction after enhanced CT scanning using the Uromedix-3D system (group A), and another 38 patients received LPN with conventional CT planning (group B). The anatomical parameters were measured in the reconstructed 3D model and the demographic data, surgical outcome and postoperative data were compared between the two groups.

RESULTS

In group A, the average time for 3D model reconstruction was (29.3∓9.7) min; the length, width and depth of the renal defect in 3D model were 3.2∓1.1 cm, 2.6∓0.9 cm and 1.7∓0.7 cm, respectively; The distance of the tumor from the collecting system was 3.8∓2.2 mm; The mean R.E.N.A.L score of the patients was 7∓1.5, and 3 patients had accessory renal artery and 2 had early branching of the renal artery. LPNs were completed via the retroperitoneal approach in all the 75 patients without conversion to open or total nephrectomy. Group A and group B showed significant differences in warm ischemic time (26.7∓6.4 vs 31.9∓7.0 min), tumor-excision time (8.4∓2.6 vs 10.4∓2.8 min), renal defect suture time (18.3∓3.9 vs 21.5∓3.4 min), 24-h volume of retroperitoneal drainage (88.6∓40.2 vs 134.3∓58.3 mL) and 48-h volume of retroperitoneal drainage (127.9∓54.5 vs 198.1∓86.3 mL), but not in the demographic data, operation time, intraoperative blood loss or postoperative hospital stay.

CONCLUSIONS

3D reconstruction of the renal masses can be completed efficiently and accurately using this system. Compared with conventional CT-based measurement, 3D spatial measurement of the anatomical structures helps to increase the precision in the performance of LPN and reduce the warm ischemia time.

Positive surgical margins are predictors of local recurrence in conservative kidney surgery for pT1 tumors

OBJECTIVES

The clinical significance of positive surgical margin (PSM) after a Nephron Sparing Surgery (NSS) is controversial. The aim of this study is to evaluate the association between PSM and the risk of disease recurrence in patients with pT1 kidney tumors who underwent NSS.

MATERIALS AND METHODS

Retrospective cohort study. A total of 314 patients submitted to a NSS due to stage pT1 renal tumor between January 2010 and June 2015 were included. Recurrence-free survival was estimated. The Cox model was used to adjust the tumor size, histological grade, pathological stage, age, surgical margins and type of approach.

RESULTS

Overall PSM was 6.3% (n=22). Recurrence was evidenced in 9.1% (n=2) of patients with PSM and 3.5% (n=10) for the group of negative surgical margin (NSM). The estimated local recurrence-free survival rate at 3 years was 96.4% (95% CI 91.9 to 100) for the NSM group and 87.8% (95% CI 71.9 to 100) for PSM group (p=0.02) with no difference in metastasis-free survival. The PSM and pathological high grade (Fuhrman grade III or IV) were independent predictors of local recurrence in the multivariate analysis (HR 12.9, 95%CI 1.8-94, p=0.011 / HR 38.3, 95%CI 3.1-467, p=0.004 respectively). Fuhrman grade proved to be predictor of distant recurrence (HR 8.1, 95%CI 1.6-39.7, p=0.011).

CONCLUSIONS

The PSM in pT1 renal tumors showed to have higher risk of local recurrence and thus, worse oncological prognosis.

Single 15-Min Protocol Yields the Same Cryoablation Size and Margin as the Conventional 10-8-10-Min Protocol: Results of Kidney and Liver Swine Experiment

INTRODUCTION

The objective was to determine the ablation size of a single 15-min freeze and compare it with the conventional 10-min freeze-8-min thaw-10-min freeze protocol. Secondary objectives were to determine the ablation margin and to ascertain whether islands of viable tissue remain within the ablation zone.

MATERIALS AND METHODS

Five adult swine under general anesthesia were used. After surgical abdominal exposure, two ablations were performed in liver and two in kidney. One ablation utilized the 15-min and the second the 10-8-10-min protocol. At maximum ice-ball, tissue ink was infused via an angiographic catheter in hepatic or renal artery to stain the non-frozen tissue. Animals were euthanized and organs examined macro- and microscopically.

RESULTS

Three histological regions were observed: (A) a viable/stained region representing the tissue outside the ice-ball, (B) a central necrotic area representing the ablated region within the ice-ball and (C) an unstained but viable margin representing the non-lethal margin within ice-ball. Ablation size did not vary with protocol but did for tissue type. Renal ablation was approximately 5 × 4 cm with both protocols, whereas liver ablation was approximately 6.7 × 4.4 cm. Ablation margin was measured at 1 mm irrespective of ablation protocol or tissue. No islands of viable tissue were identified within the ablation zone.

DISCUSSION

Fifteen-minute cryoablation yielded an ablation size and margin identical to that of the conventional 10-8-10-min protocol. Within the ablated region, cell death was uniform. The only difference was a larger cryoablation zone in hepatic tissue compared to renal tissue, likely attributable to differences in blood perfusion.

Histopathologic analysis of stage pT1b kidney neoplasms for optimal surgical margins of nephron-sparing surgery

Objective

To evaluate the pathological features and define the optimal surgical margins (SM) of nephron-sparing surgery (NSS) for kidney neoplasms 4–7 cm (stage pT1b) on preoperative imaging.

Materials and methods

The retrospective study included 748 patients who were diagnosed stage pT1b renal tumors and underwent either radical nephrectomy (RN, n = 475) or NSS (n = 273) from January 2004 to March 2017. The tumor size, pathological subtype, Fuhrman grade, status of peritumoral pseudocapsule (PC) and tumor multifocality were recorded. The relationship between peritumoral PC and positive SM was calculated statistically by Fisher’s exact probability test.

Results

The mean tumor diameter was 5.4 cm (range: 4.1–7.0 cm), 65 (8.7%) cases were discovered with multifocal lesions and 686 (91.7%) were surrounded with peritumoral PC in all 748 specimens. 57 (8.3%) of 686 cases were proved with tumor infiltrated beyond PC [infiltration (+)], and the presence of PC infiltration (+) was significantly correlated with positive SM (p = 0.016). The infiltrative depth of tumor cells into renal parenchyma beyond PC was all limited in 3 mm and the proportion of ≤ 1, 1–2 and 2–3 mm was 21.1% (12/57), 59.6% (34/57) and 19.3% (11/57), respectively.

Conclusions

Our report indicates a 3 mm excisional margin is acceptable to ensure negative SM when operating NSS on stage pT1b kidney neoplasms.

Pathologic analysis of non-neoplastic parenchyma in renal cell carcinoma: a comprehensive observation in radical nephrectomy specimens

Background

This study provides a comprehensive examination of the histological features of non-neoplastic parenchyma in renal cell carcinoma (RCC). We prospectively collected radical nephrectomy (RN) specimens, to analyze the histological changes within peritumoral and distant parenchyma.

Methods

Data of patients who underwent RN and had no known history of diabetes, hypertension, hyperlipidemia, or chronic kidney disease etc., were prospectively collected. Tumor pseudo-capsule (PC), and parenchyma within 2 cm from tumor margin, were pathologically assessed. The parenchyma beyond PC or tumor margin was divided into 20 subsections of 1 mm in width. Histological changes, including chronic inflammation, glomerulosclerosis, arteriosclerosis and nephrosclerosis, were given scores of 0, 1, 2 or 3 for each subsection of each specimen, according to their severity. The 20 subsections of each specimen were further divided into four groups according to the distance from the tumor edge (group 1: 0–2 mm; group 2: 2–5 mm; group 3: 5–10 mm; group 4: 10–20 mm), to better compare the peritumoral parenchyma with the distant parenchyma.

Results

In total, 53 patients were involved in this study. All tumors were confirmed RCCs (clear cell vs. papillary vs. chromophobe were 83% vs. 5.7% vs. 11.3%, respectively), with a mean size of 5.6 cm. Histological changes were more severe in peritumoral parenchyma close to PC or tumor edge (0–5 mm), and less common within parenchyma more distant from the tumor (5–20 mm) (p < 0.001). chronic inflammation and nephrosclerosis were the most common changes especially in peritumoral parenchyma (0-2 mm). PC was present in 49 tumors (92.5%), and PC invasion occurred in 5 cases (10.2%). Mean PC thickness was 0.7 mm. PCs were more likely to be present in clear cell RCC or papillary RCC than in chromophobe RCC (100% vs. 100% vs. 33.3%, respectively; p < 0.001).

Conclusions

Most RCCs have a well-developed PC, especially clear cell RCC. Histological changes mainly occur in peritumoral parenchyma, being rather uncommon in distant parenchyma. A compression band filled with severe histological changes was typically observed in renal parenchyma close to the tumor. Its preservation while performing an enucleation margin may not be entirely necessary.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3849-5) contains supplementary material, which is available to authorized users.

Evaluation of Electrical Impedance Spectroscopy-on-a-Needle as a Novel Tool to Determine Optimal Surgical Margin in Partial Nephrectomy

A hypodermic needle has been introduced incorporating an electrical impedance spectroscopy (EIS) sensor, called micro-EIS-on-a-needle for depth profiling (μEoN-DP). The μEoN-DP can locate endophytic renal tumors as well as determine tumor margins by detecting the impedance difference between normal and cancer tissues. To evaluate the μEoN-DP as a novel tool to determine the optimal surgical margin during partial nephrectomy (PN), the electrical impedance differences between renal parenchymal tissues and renal cell carcinoma (RCC) tumors are investigated with regard to the distance from the tumors. Optimal frequencies at which the discrimination extent is maximized are suggested based on the discrimination index. The resistance and capacitance of normal and cancer tissues are extracted using electrical equivalent circuit by excluding the influences of other electrical components on the sensor output. The extracted resistance and capacitance of cancer tissues are 37.8% larger and 25.7% smaller than that of normal tissues, respectively. Additionally, high sensitivity and specificity are obtained by using extracted resistance and capacitance, thus implying that the μEoN-DP shows promise as a supplementary tool for PN margin evaluation and decreasing the prevalence of positive surgical margins while maximizing parenchymal preservation.

The percentage of resected and ischemic volume determined by a geometric model is a significant predictor of renal functional change after partial nephrectomy

Purpose

The percentage of parenchyma preserved plays a predominant role in predicting renal function after partial nephrectomy (PN). Currently there is no standard method to estimate preserved renal parenchyma. In this study we propose a formula of the percentage of resected and ischemic volume (PRAIV) determined by a geometric model and evaluate the relationships between renal functional change and PRAIV as well as other clinical parameters.

Materials and Methods

We identified 71 patients who underwent open PN between January 2004 and April 2014. Assuming the kidney to be an ellipsoid with bilaterally equal volume and tumor to be a sphere, we calculated PRAIV by integral calculus. Nadir estimated glomerular filtration rate (eGFR) between postoperative 3 and 12 months were recorded. The correlation between percent eGFR reduction, PRAIV, and other clinical parameters were examined.

Results

On univariate analysis, age (p=0.03), depth of tumor invasion (p=0.004), C index (p=0.003), RAIV (p=0.04), and PRAIV (p<0.001) were correlated with percent reduction of eGFR. However, only age (p=0.007) and PRAIV (p<0.001) were significantly correlated with percent reduction of eGFR on multivariate analysis. Depicting these values along the regression line, we found R² was 0.194 and 0.073 for PRAIV and age, respectively.

Conclusions

PRAIV determined by a geometric model is a significant predictor of renal functional change after PN. Using PRAIV, we can estimate percent eGFR reduction preoperatively for better patient consultation and surgical planning.

Histopathologic analysis of tumor bed and peritumoral pseudocapsule after in vitro tumor enucleation on radical nephrectomy specimen for clinical T1b renal cell carcinoma

PURPOSE

This study was designed to assess the feasibility and histopathologic safety of tumor enucleation for renal cell carcinoma, through histopathologic analysis of the tumor bed and peritumoral pseudocapsule (PC) after in vitro tumor enucleation.

MATERIALS AND METHODS

We studied 176 radical nephrectomy specimens for clinical T1b renal cell carcinoma in our institution, from January 2013-February 2016. Immediately after the kidney was excised, the tumor of radical specimen was enucleated in vitro. The tumor bed parenchyma of 15mm beyond the PC was examined to investigate the possible presence of tumor invasion or satellite lesions. The PC invasion was also evaluated.

RESULTS

The average tumor size was 5.7±0.7cm. The histopathologic evaluation revealed that 68.2% of tumors were clear cell renal cell carcinoma (RCC). The pathological staging showed that 92.6% of tumors were pT1b, 2.8% were pT2, and 4.5% were pT3a. For clinical T1b RCC, tumor infiltration on tumor bed was detected in 6 cases (3.4%), and satellite lesion was detected in 3 (1.7%). In the group of grade 1 to 2, 4 (2.3%) were found with residual tumor, and 5 (2.8%) in the group of grade 3 to 4 (P = 0.133). Papillary RCC had the highest rate of residual tumors (8.8%). A statistically significant association of peritumoral PC invasion with tumor size and pathologic grade was observed. Median follow-up was 23 months (range: 6-43) with a recurrence rate of 6.3% (11 of 176) and a cancer-specific mortality rate of 2.8% (5 of 176).

CONCLUSIONS

For clinical T1b renal cell carcinoma, the risks of tumor infiltration or satellite lesions on enucleation tumor bed or both are relatively low. Peritumoral PC invasion is associated with tumor size and pathologic stage. Tumor enucleation is a histopathologically safe technique for patients undergoing partial nephrectomy.

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.

Robust augmented reality registration method for localization of solid organs' tumors using CT-derived virtual biomechanical model and fluorescent fiducials

BACKGROUND

Augmented reality (AR) is the fusion of computer-generated and real-time images. AR can be used in surgery as a navigation tool, by creating a patient-specific virtual model through 3D software manipulation of DICOM imaging (e.g., CT scan). The virtual model can be superimposed to real-time images enabling transparency visualization of internal anatomy and accurate localization of tumors. However, the 3D model is rigid and does not take into account inner structures' deformations. We present a concept of automated AR registration, while the organs undergo deformation during surgical manipulation, based on finite element modeling (FEM) coupled with optical imaging of fluorescent surface fiducials.

METHODS

Two 10 × 1 mm wires (pseudo-tumors) and six 10 × 0.9 mm fluorescent fiducials were placed in ex vivo porcine kidneys (n = 10). Biomechanical FEM-based models were generated from CT scan. Kidneys were deformed and the shape changes were identified by tracking the fiducials, using a near-infrared optical system. The changes were registered automatically with the virtual model, which was deformed accordingly. Accuracy of prediction of pseudo-tumors' location was evaluated with a CT scan in the deformed status (ground truth). In vivo: fluorescent fiducials were inserted under ultrasound guidance in the kidney of one pig, followed by a CT scan. The FEM-based virtual model was superimposed on laparoscopic images by automatic registration of the fiducials.

RESULTS

Biomechanical models were successfully generated and accurately superimposed on optical images. The mean measured distance between the estimated tumor by biomechanical propagation and the scanned tumor (ground truth) was 0.84 ± 0.42 mm. All fiducials were successfully placed in in vivo kidney and well visualized in near-infrared mode enabling accurate automatic registration of the virtual model on the laparoscopic images.

CONCLUSIONS

Our preliminary experiments showed the potential of a biomechanical model with fluorescent fiducials to propagate the deformation of solid organs' surface to their inner structures including tumors with good accuracy and automatized robust tracking.

Study of the Kidney Tumor-Parenchymal Interface after Neoadjuvant Treatment with Axitinib for Locally Advanced Clear Cell Renal Cell Carcinoma: Matched Analysis from a Phase II Trial

PURPOSE

The aim of this study was to evaluate histological changes in the tumor-parenchymal interface in clear cell renal cell carcinoma after neoadjuvant axitinib treatment.

MATERIALS AND METHODS

We obtained clinical and pathology materials from 23 patients with clear cell renal cell carcinoma treated with neoadjuvant axitinib in a phase II clinical trial and from 23 matched patients with clear cell renal cell carcinoma who underwent upfront surgery. Histology of the tumor pseudocapsule and the peritumor kidney parenchymal change was evaluated and compared between the 2 cohorts.

RESULTS

A tumor pseudocapsule was noted in all 23 patients who received neoadjuvant axitinib and in all 23 control patients. Most pseudocapsules were noncontinuous and only partially covered the tumor, including in 17 of 23 axitinib cases (74%) and 19 of 23 controls (83%). In axitinib cases the median thickness of the intrarenal and extrarenal pseudocapsule was 1.4 and 2.4 mm, respectively, which was significantly thicker than in control cases (intrarenal p = 0.0008 and extrarenal p <0.0001). The thickness of the pseudocapsule in axitinib treated cases was more frequently irregular compared to that in controls (16 of 23 or 70% and 9 of 23 or 39%, respectively, p = 0.0746). Inflammation, nephrosclerosis, glomerulosclerosis and arteriosclerosis decreased with increasing distance from the tumor edge in the neoadjuvant axitinib and control groups.

CONCLUSIONS

The tumor pseudocapsule becomes irregularly thick after neoadjuvant axitinib therapy. Although axitinib likely evokes a strong fibrous reaction in the tumor-parenchymal interface, it does not affect the frequency of infiltrative tumor invasion to the outside of the pseudocapsule or the degree of atrophic/inflammatory change in tissue surrounding the tumor. These findings support the notion that partial nephrectomy could be safely done in well selected patients after neoadjuvant axitinib.

Comparison of the Width of Peritumoral Surgical Margin in Open and Robotic Partial Nephrectomy: A Propensity Score Matched Analysis

Background

To compare the surgical margin status after open partial nephrectomy (OPN) and robotic partial nephrectomy (RPN) performed in patients with T1a renal cell carcinoma (RCC).

Methods

This was a propensity score-matched study including 702 patients with cT1a RCC treated with partial nephrectomy (PN) between May 2003 and July 2015. Perioperative parameters, including surgical margin width after PN, were compared between two surgical methods. After determining propensity score for tumor size and location, the width of peritumoral surgical margin was investigated. Multivariate logistic analysis to predict peritumoral surgical margin less than 1mm was analyzed.

Results

The mean width of peritumoral surgical margin was 2.61 ± 2.15 mm in OPN group (n = 385), significantly wider than the 2.29 ± 2.00 mm of RPN group (n = 317) (p = 0.042). The multivariate analysis showed surgical methods was significant factors to narrow surgical margin less than 1mm (p = 0.031). After propensity score matching, the surgical margin width was significantly longer in OPN (2.67 ± 2.14 mm) group than RPN (2.25 ± 2.03 mm) group (p = 0.016). A positive resection margin occurred in 7 (1.8%) patients in the OPN group and 4 (1.3%) in the RPN group. During the median follow-up of 48.3 months, two patients who underwent OPN had tumor bed recurrence.

Conclusions

RPN may result in a narrower peritumoral surgical margin than OPN. Further investigation on the potential impact of such a phenomenon should be performed in a larger-scale study.

Ambient ionization mass spectrometric analysis of human surgical specimens to distinguish renal cell carcinoma from healthy renal tissue

Touch spray-mass spectrometry (TS-MS) is an ambient ionization technique (ionization of unprocessed samples in the open air) that may find intraoperative applications in quickly identifying the disease state of cancerous tissues and in defining surgical margins. In this study, TS-MS was performed on fresh kidney tissue (∼1-5 cm(3)), within 1 h of resection, from 21 human subjects afflicted by renal cell carcinoma (RCC). The preliminary diagnostic value of TS-MS data taken from freshly resected tissue was evaluated. Principal component analysis (PCA) of the negative ion mode (m/z 700-1000) data provided the separation between RCC (16 samples) and healthy renal tissue (13 samples). Linear discriminant analysis (LDA) on the PCA-compressed data estimated sensitivity (true positive rate) and specificity (true negative rate) of 98 and 95 %, respectively, based on histopathological evaluation. The results indicate that TS-MS might provide rapid diagnostic information in spite of the complexity of unprocessed kidney tissue and the presence of interferences such as urine and blood. Desorption electrospray ionization-MS imaging (DESI-MSI) in the negative ionization mode was performed on the tissue specimens after TS-MS analysis as a reference method. The DESI imaging experiments provided phospholipid profiles (m/z 700-1000) that also separated RCC and healthy tissue in the PCA space, with PCA-LDA sensitivity and specificity of 100 and 89 %, respectively. The TS and DESI loading plots indicated that different ions contributed most to the separation of RCC from healthy renal tissue (m/z 794 [PC 34:1 + Cl](-) and 844 [PC 38:4 + Cl](-) for TS vs. m/z 788 [PS 36:1 - H](-) and 810 [PS 38:4 - H](-) for DESI), while m/z 885 ([PI 38:4 - H](-)) was important in both TS and DESI. The prospect, remaining hurdles, and future work required for translating TS-MS into a method of intraoperative tissue diagnosis are discussed. Graphical abstract Touch spray-mass spectrometry used for lipid profiling of fresh human renal cell carcinoma. Left) Photograph of the touch spray probe pointed at the MS inlet. Right) Average mass spectra of healthy renal tissue (blue) and RCC (red).

Surgical margin does not influence recurrence rate in pT1 clear cell renal cell carcinoma after partial nephrectomy: A multicenter study

PURPOSE

To assess the risk factors of positive surgical margins (PSM) and the influence of margin status on recurrence in pT1 clear cell renal cell carcinoma (RCC) following partial nephrectomy (PN).

MATERIALS AND METHODS

Patients (1,831) with pathologically confirmed stage T1 clear cell RCC were retrospectively analyzed following PN at eight institutions in Korea between 1999 and 2011. Demographics, operative data, pathological margin status, and site of recurrence were analyzed.

RESULTS

Resection margins were positive in 31 patients (1.7% of the cohort) on final pathology. None of the clinicopathological parameters were significantly related to the marginal status (all P > 0.05). During a median follow-up of 32.5 months, local recurrences were observed in 0.4% of negative surgical margins. There was no local recurrence in any of the cases with PSM. Distant recurrences developed in 1.7% of negative surgical margins and 3.2% of PSM. There were no significant differences in recurrence-free survival by margin status (P = 0.566).

CONCLUSIONS

Our multi-institutional data suggest that marginal status does not influence tumor recurrence risk in pT1 clear cell RCC after PN. Careful surveillance seems to be a sufficient strategy in this clinical scenario. J. Surg. Oncol. 2016;114:70-74. © 2016 Wiley Periodicals, Inc.

Efficacy of Partial Nephrectomy for Renal Tumors &gt;4 cm: Comparison With Renal Tumors ≤4 cm

Partial nephrectomy has become a treatment of choice for clinical T1a renal masses. Some international guidelines suggest that partial nephrectomy can be applied also in clinical T1b tumors. The aim of this study was to evaluate the feasibility of partial nephrectomy for tumors larger than 4 cm. We reviewed the medical records of 1280 patients who underwent partial nephrectomy and had pathologically confirmed malignancy. Patients were categorized into two groups by the size of tumors on computed tomography image, with a cutoff value of 4 cm. The oncologic and functional outcomes were compared between the two groups. Recurrence-free survival after surgery was estimated using the Kaplan-Meier method. Of the 1280 patients, 203 patients (15.9%) had renal tumors larger than 4 cm. There were significantly more exophytic tumors (P &lt; 0.001) and the R.E.N.A.L. scores were significantly higher (P &lt; 0.001) in partial nephrectomy &gt;4 cm. Mean ischemic times were significantly different (P &lt; 0.001). After 24 months, mean creatinine level between partial nephrectomy &gt;4 cm and partial nephrectomy ≤4 cm was not different significantly (P = 0.554). And the percent changes of glomerular filtration rate after partial nephrectomy were not different at last follow-up (P = 0.082). The 5-year recurrence-free survival rates were 96.6% in partial nephrectomy ≤4 cm, and 94.5% in partial nephrectomy &gt;4 cm (P = 0.416). Based on the present findings, partial nephrectomy for tumors larger than 4 cm showed comparable feasibility and safety to partial nephrectomy for tumors ≤4 cm considering oncologic and functional outcomes, despite longer operative and ischemic time.

Self-assessment of surgical technique leads to reduction of positive surgical margins in partial nephrectomy

The background of the study was to examine potential causes for a positive surgical margin (PSM) and develop strategies to improve surgical outcomes. A retrospective review of consecutive partial nephrectomy cases for renal cell carcinoma was performed. We divided the patients into 2 groups. The first group consisted of the first 67 renal tumors in 65 patients that underwent our early surgical technique. The second group consisted of the next 45 renal tumors in 39 patients that underwent the revised surgical technique which included wider resections and robotically controlled ultrasound. Our primary outcome was margin status and secondary outcome was disease recurrence. Univariate and multivariate analyses were performed to determine factors that resulted in a PSM. Positive margins were detected in 19 out of 67 (28 %) renal tumors in the early technique group compared to 1 out of 45 (2 %) positive margins in the revised technique group (p < 0.001). On multivariate analysis, only technique modification (OR 0.04, p = 0.003) and larger tumor size (OR 0.41, p = 0.01) were significant predictors of a lower rate of PSM. Smaller tumors were more common in robotic assisted partial nephrectomies which had a higher rate of PSM on univariate analysis (OR 3.51, p = 0.04). Only one patient with a PSM experienced a systemic disease recurrence. In our experience, self-assessment and technique modification resulted in a dramatic PSM improvement. Smaller tumors were associated with PSM. It is important for all surgeons to periodically look at their own surgical outcomes and modify their surgical technique accordingly.

Does the Renal Parenchyma Adjacent to the Tumor Contribute to Kidney Function? A Critical Analysis of Glomerular Viability in Partial Nephrectomy Specimens

OBJECTIVE

To evaluate the viability of glomeruli in the peritumor parenchyma of partial nephrectomy specimens removed for renal cell carcinoma (RCC) and relate it to kidney function, to better understand the contribution of peritumor parenchyma to renal function.

MATERIALS AND METHODS

A retrospective analysis of 53 partial nephrectomies containing RCC was performed. Glomeruli within 0.25-cm increments from the tumor were quantified and histologically assessed for viability. Tumor size, minimum and maximum margin size, and pre- and postoperative estimated glomerular filtration rate (eGFR) were obtained.

RESULTS

Glomerular viability positively correlated with distance from tumor with mean viable glomeruli in successive 0.25-cm increments of 0-0.25 cm, 58%; 0.25-0.5 cm, 80%; 0.5-0.75 cm, 90%; and 0.75-1.0 cm, 92%. Glomerular viability near the tumor did not correlate with preoperative eGFR, whereas decreased viability further from the tumor did correlate with worse preoperative eGFR. Tumor size showed a nonstatistically significant positive trend with minimum (median 0.15 cm) and maximum margin (median 0.7 cm) sizes. Percent change of glomerular filtration rate did not correlate with margin size (P = .190).

CONCLUSION

Renal parenchyma immediately adjacent to RCC contains fewer viable glomeruli compared with the parenchyma further from the tumor. Based on this information, attempts to preserve all non-neoplastic renal parenchyma via a surgical margin approaching zero may not necessarily result in clinically relevant differences in the amount of viable glomeruli remaining or the renal function preserved.

Cold Atmospheric Plasma Treatment Induces Anti-Proliferative Effects in Prostate Cancer Cells by Redox and Apoptotic Signaling Pathways

One of the promising possibilities of the clinical application of cold plasma, so-called cold atmospheric plasma (CAP), is its application on malignant cells and cancer tissue using its anti-neoplastic effects, primarily through the delivery of reactive oxygen and nitrogen species (ROS, RNS). In this study, we investigated the impact of CAP on cellular proliferation and consecutive molecular response mechanisms in established prostate cancer (PC) cell lines. PC cells showed a significantly reduced cell growth following CAP treatment as a result of both an immediate increase of intracellular peroxide levels and through the induction of apoptosis indicated by annexin V assay, TUNEL assay, and the evaluation of changes in nuclear morphology. Notably, co-administration of N-acetylcysteine (NAC) completely neutralized CAP effects by NAC uptake and rapid conversion to glutathione (GSH). Vitamin C could not counteract the CAP induced effects on cell growth. In summary, relatively short treatments with CAP of 10 seconds were sufficient to induce a significant inhibition of cancer proliferation, as observed for the first time in urogenital cancer. Therefore, it is important to understand the mode of CAP related cell death and clarify and optimize CAP as cancer therapy. Increased levels of peroxides can alter redox-regulated signaling pathways and can lead to growth arrest and apoptosis. We assume that the general intracellular redox homeostasis, especially the levels of cellular GSH and peroxidases such as peroxiredoxins affect the outcome of the CAP treatment.

A Literature Review of Renal Surgical Anatomy and Surgical Strategies for Partial Nephrectomy

CONTEXT

A detailed understanding of renal surgical anatomy is necessary to optimize preoperative planning and operative technique and provide a basis for improved outcomes.

OBJECTIVE

To evaluate the literature regarding pertinent surgical anatomy of the kidney and related structures, nephrometry scoring systems, and current surgical strategies for partial nephrectomy (PN).

EVIDENCE ACQUISITION

A literature review was conducted.

EVIDENCE SYNTHESIS

Surgical renal anatomy fundamentally impacts PN surgery. The renal artery divides into anterior and posterior divisions, from which approximately five segmental terminal arteries originate. The renal veins are not terminal. Variations in the vascular and lymphatic channels are common; thus, concurrent lymphadenectomy is not routinely indicated during PN for cT1 renal masses in the setting of clinically negative lymph nodes. Renal-protocol contrast-enhanced computed tomography or magnetic resonance imaging is used for standard imaging. Anatomy-based nephrometry scoring systems allow standardized academic reporting of tumor characteristics and predict PN outcomes (complications, remnant function, possibly histology). Anatomy-based novel surgical approaches may reduce ischemic time during PN; these include early unclamping, segmental clamping, tumor-specific clamping (zero ischemia), and unclamped PN. Cancer cure after PN relies on complete resection, which can be achieved by thin margins. Post-PN renal function is impacted by kidney quality, remnant quantity, and ischemia type and duration.

CONCLUSIONS

Surgical renal anatomy underpins imaging, nephrometry scoring systems, and vascular control techniques that reduce global renal ischemia and may impact post-PN function. A contemporary ideal PN excises the tumor with a thin negative margin, delicately secures the tumor bed to maximize vascularized remnant parenchyma, and minimizes global ischemia to the renal remnant with minimal complications.

PATIENT SUMMARY

In this report we review renal surgical anatomy. Renal mass imaging allows detailed delineation of the anatomy and vasculature and permits nephrometry scoring, and thus precise, patient-specific surgical planning. Novel off-clamp techniques have been developed that may lead to improved outcomes.

Feasibility of omitting cortical renorrhaphy during robot-assisted partial nephrectomy: a matched analysis

BACKGROUND AND PURPOSE

To assess the safety of omitting cortical renorrhaphy during robot-assisted partial nephrectomy and measure preliminary functional outcomes.

PATIENTS AND METHODS

Fifteen robot-assisted partial nephrectomies were performed with a running, base-layer suture for the collecting system and vessel hemostasis but without cortical renorrhaphy. The nonrenorrhaphy group was matched 1:2 by R.E.N.A.L. nephrometry score to a running, sliding-clip cortical renorrhaphy group retrospectively. Intraoperative blood loss, urine leaks, postoperative bleeds, and functional outcomes were evaluated. Predictors of %volume loss were evaluated using multivariable regression.

RESULTS

No differences were seen between renorrhaphy and nonrenorrhaphy in sex (P=0.53), age (P=0.14), body mass index (P=0.08), Charlson score (P=0.44), tumor diameter (P=0.55), nephrometry score (P=0.77), preoperative glomerular filtration rate (GFR, P=0.63), or the amount of resected healthy kidney margin (P=0.21). Warm ischemia time was less for the nonrenorrhaphy group (P<0.002). One pseudoaneurysm necessitating embolization (1/30=3%) was seen in the renorrhaphy group compared with none in the nonrenorrhaphy group. No urine leaks occurred in either group. The median %GFR loss was 8.8% for renorrhaphy and 4.4% for nonrenorrhaphy (P=0.14) at a median follow-up of 4.1 months. The median %volume loss was 17 cm(3) for renorrhaphy and 9 cm(3) for nonrenorrhaphy (P=0.003). In a multivariable model, both cortical renorrhaphy (P=0.004) and tumor diameter (P=0.004) were predictors of %volume loss.

CONCLUSION

Omission of cortical renorrhaphy appears feasible with no urine leaks or bleeding complications observed. The percent renal volume loss was improved by omission of cortical renorrhaphy. Reconstruction technique is important to control for when studying renal function after partial nephrectomy.