Excised Parenchymal Mass During Partial Nephrectomy: Functional Implications

SAVE Testis-sparing score: a multicenter retrospective study of a novel predictive tool for quantifying testicular tumors

BACKGROUND

Testis-sparing surgery (TSS) is a safe treatment for patients with benign testicular tumors. Presently, assessments for evaluating the suitability of TSS are poorly standardized, partially because testicular anatomical elements cannot be quantitatively described.

MATERIALS AND METHODS

The authors developed a scoring method known as the SAVE testis-sparing score based on four critical and accessible anatomical features of a testicular tumor. The SAVE score ranges from 0 to 8 and is divided into four risk classes ( low , medium , high , and extremely high ) to evaluate the feasibility of TSS, wherein low-risk indicates high feasibility and vice versa. This study included 444 testicular tumor patients from eight centers. Among them, 216 patients (model group: 151 patients, validation group: 65 patients) were included in the modeling analysis, and the other 228 patients from children's centers were included in the proportion analysis. Using retrospective data, patient characteristics associated with surgical methods were identified. Furthermore, a multivariate logistic regression model was built quantify the associations between these characteristics and the surgery method. The receiver operator characteristic curve was used to evaluate the classification efficiency of SAVE.

RESULTS

The SAVE testis-sparing score includes size (tumor size as maximal diameter), available testicular tissue volume, volume ratio of the tumor to the testis, and the exophytic / endophytic properties of the tumor. The SAVE scoring system accurately classified the suitability of TSS based on the complexity of benign testicular tumors.

CONCLUSION

The SAVE score is a reproducible and robust tool for quantitatively describing the anatomical characteristics of benign testicular tumors and guide the preoperative evaluation of TSS.

Partial versus radical nephrectomy for the treatment of pT3aN0M0 renal cell carcinoma: A propensity score analysis

BACKGROUND

The survival benefit of partial nephrectomy (PN) in pT3a RCC patients is controversial. Here we aimed to explore the potential benefit of PN for pT3aN0M0 renal cell carcinoma (RCC).

MATERIAL AND METHODS

Data of patients with pT3aN0M0 RCC who were diagnosed between 2010 and 2012 in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. Overall survival (OS) and cancer specific survival (CSS) were compared using a Cox proportional hazards model between PN and radical nephrectomy (RN) in pT3aN0M0 RCC. Propensity score (-adjusted, -stratified, -weighted, and -matched) analyses were performed to control for imbalances in individual risk factors.

RESULTS

A total of 1277 patients with pT3aN0M0 RCC were identified, of whom 200 patients were treated with PN and 1077 patients were RN. PN showed favorable OS and CSS in 0-4 cm pT3aN0M0 RCC (P < 0.05), and similar OS and CSS in 4-7 cm pT3aN0M0 RCC, compared with RN using un-adjusted analyses. The Propensity score analyses further demonstrated the survival benefit of PN compared with the RN in 0-4 cm pT3aN0M0 RCC (P < 0.05).

CONCLUSIONS

In this retrospective study, PN was associated with improved survival compared with RN in 0-4 cm pT3aN0M0 RCC. Moreover, survival was comparable between PN and RN in 4-7 cm pT3aN0M0 RCC. These data provided evidence that PN could be an alternative choice for T3aN0M0 RCC less than 7 cm. Particularly, patients with 0-4 cm pT3aN0M0 RCC might benefit from PN.

Every decade counts: a narrative review of functional recovery after partial nephrectomy

OBJECTIVE

To provide a narrative review of the major advances regarding ischaemia and functional recovery after partial nephrectomy (PN), along with the ongoing controversies.

METHODS

Key articles reflecting major advances regarding ischaemia and functional recovery after PN were identified. Special emphasis was placed on contributions that changed perspectives about surgical management. Priority was also placed on randomized trials of off-clamp vs on-clamp cohorts.

RESULTS

A decade ago, 'Every minute counts' was published, showing strong correlations between duration of ischaemia and development of acute kidney injury (AKI) and chronic kidney disease after clamped PN. This reinforced perspectives that ischaemia was the main modifiable factor that could be addressed to improve functional outcomes and helped spur efforts towards reduced or zero ischaemia PN. These approaches were associated with strong functional recovery and some peri-operative risk, although they were generally safe in experienced hands. Further research demonstrated that, when parenchymal volume changes were incorporated into the analyses, ischaemia lost statistical significance, and percent parenchymal volume saved proved to be the main determinant. Cold ischaemia was confirmed to be highly protective, and limited warm ischaemia also proved to be safe. The reconstructive phase of PN, with avoidance of parenchymal devascularization, appears to be most important for functional outcomes. Randomized trials of on-clamp vs off-clamp PN have shown minimal impact of ischaemia on functional recovery.

CONCLUSIONS

The past decade has witnessed great progress regarding functional recovery after PN, with many lessons learned. However, there are still unanswered questions, including: What is the threshold of warm ischaemia at which irreversible ischaemic injury begins to develop? Are some cohorts at increased risk for AKI or irreversible ischaemic injury? and Which patients should be prioritized for zero-ischaemia PN?

Robot-assisted versus conventional laparoscopic partial nephrectomy for renal hilar tumors: Parenchymal preservation and functional recovery

OBJECTIVE

To determine whether robot-assisted laparoscopic partial nephrectomy (RALPN) can benefit patients in terms of functional recovery in the treatment of renal hilar tumors compared to conventional laparoscopic partial nephrectomy (CLPN).

METHODS

Between January 2019 and July 2021, patients with hilar tumors who underwent partial nephrectomy (PN) were acquired at our center and were classified into RALPN and CLPN groups. Ipsilateral parenchymal volume (IPV) and glomerular filtration rate (GFR) were determined independently 3-5 days before and 3 months after PN using contrast-enhanced computed tomography and nuclear renal scans. Pearson correlation was used to determine the link between ipsilateral GFR preservation and IPV preserved. Concurrently, multivariable analysis was employed to determine characteristics associated with functional recovery.

RESULTS

A total of 96 patients with hilar tumors were studied, of which 41 received RALPN and 55 received CLPN. Excisional parenchymal volume was 27 and 37 cm³ (p = 0.005) in RALPN and CLPN groups, respectively, and IPV preserved was 77% and 68% (p < 0.001). Furthermore, the ipsilateral GFR preserved was 77.7% and 75.3%, respectively (p = 0.003). On Pearson correlation, ipsilateral GFR preservation was linked with IPV preserved (r = 0.36, p < 0.001). According to a multivariate study, baseline GFR, IPV preserved, and surgical procedures (RALPN vs. CLPN) were significant factors influencing functional recovery.

CONCLUSION

Our study suggests that RALPN, rather than CLPN, can achieve better functional recovery in the treatment of hilar tumors due to its ability to win more IPV preserved. RALPN should be recommended as the first-line treatment for hilar tumors, but randomized controlled trials are required to validate our findings.

Estimated Glomerular Filtration Rate Decline at 1 Year After Minimally Invasive Partial Nephrectomy: A Multimodel Comparison of Predictors

Background

Long-term renal function after partial nephrectomy (PN) is difficult to predict as it is influenced by several modifiable and nonmodifiable variables, often intertwined in complex relations.

Objective

To identify variables influencing long-term renal function after PN and to assess their relative weight.

Design, setting, and participants

A total of 457 patients who underwent either robotic (n = 412) or laparoscopic PN (n = 45) were identified from a multicenter international database.

Outcome measurements and statistical analysis

The 1-yr estimated glomerular filtration rate (eGFR) percentage loss (1YPL), defined as the eGFR percentage change from baseline at 1 yr after surgery, was the outcome endpoint. Predictors evaluated included demographic data, tumor features, and operative and postoperative variables. Bayesian multimodel analysis of covariance was used to build all possible models and compare the fit of each model to the data via model Bayes factors. Bayesian model averaging was used to quantify the support for each predictor via the inclusion Bayes factor (BF_incl). High-dimensional undirected graph estimation was used for network analysis of conditional independence between predictors.

Results and limitations

Several models were found to be plausible for estimation of 1YPL. The best model, comprising postoperative eGFR percentage loss (PPL), sex, ischemia technique, and preoperative eGFR, was 207 times more likely than all the other models regarding relative predictive performance. Its components were part of the top 44 models and were the predictors with the highest BF_incl. The role of cold ischemia, solitary kidney status, surgeon experience, and type of renorraphy was not assessed.

Conclusions

Preoperative eGFR, sex, ischemia technique, and PPL are the best predictors of eGFR percentage loss at 1 yr after minimally invasive PN. Other predictors seem to be irrelevant, as their influence is insignificant or already nested in the effect of these four parameters.

Patient summary

Kidney function at 1 year after partial removal of a kidney depends on sex, the technique used to halt blood flow to the kidney during surgery, and kidney function at baseline and in the early postoperative period.

Determinants and Implications of Excised Parenchymal Mass on Robotic-Assisted Partial Nephrectomy Outcomes

OBJECTIVES

To evaluate the association between excised parenchymal mass (EPM) and postoperative renal function (eGFR) following robotic-assisted partial nephrectomy (RAPN). EPM is the amount of healthy renal parenchyma excised during partial nephrectomy in order to achieve safe surgical margins.

METHODS

We evaluated 406 consecutive RAPN performed by a single surgeon to eliminate variations in technique as a factor in EPM. EPM (mL) = (specimen volume * π/6) - (tumor volume * π/6). RENAL score was categorized as easy (4-6), moderate (7-9), or hard (10-12). EPM was grouped into four categories: ≤ 3.9 mL, 4.0-9.9 mL, 10.0-17.7 mL, and >17.7 mL. eGFR was evaluated preoperatively, postoperative day 1 (POD1), 1 month, and 6 months postoperatively.

RESULTS

Median age was 63 years (22-84 years), 252 (62.1%) were male, and median EPM was 9.9 mL (interquartile range 3.9 to 17.7 mL). The median EPM and interquartile range for each RENAL category was 3.7 mL (2.0, 7.9), 12 mL (5.7, 19.4), and 16.2 mL (7.9, 24.3), respectively. Higher EPM was associated with worse changes in eGFR at POD1 (P = 0.005) and 1 month after RAPN (P = 0.002) but was not statistically significant at the 6-month time period (P = 0.35) CONCLUSION: Increased tumor complexity is associated with an increase in EPM during RAPN. Increased EPM is associated with eGFR decline at POD1 and 1 month post RAPN but not at 6 months postoperatively.

Mimics and Pitfalls in Renal Imaging

There are several potential pitfalls that radiologists face when interpreting images of the kidneys. Some result from image acquisition and can arise from the imaging equipment or imaging technique, whereas others are patient related. Another category of pitfalls relates to image interpretation. Some difficulties stem from methods to detect enhancement after contrast administration, whereas others are benign entities that can mimic a renal tumor. Finally, interpretation and diagnosis of fat-containing renal masses may be tricky due to the complexities discerning the pattern of fat within a mass and how that translates to an accurate diagnosis.

Measuring volumetric segmentation changes in the ipsilateral and contralateral kidney postpartial nephrectomy

OBJECTIVE

To analyze the volumetric changes of the ipsilateral and contralateral kidneys and their effect on functional outcome post partial nephrectomy using segmentation analysis.

PATIENTS AND METHODS

We have analyzed the data of 119 patients from a single surgeon series of partial nephrectomy patients. Median follow-up was 11.40 months. Patients with bilateral tumors, and solitary kidney were excluded from analysis. Volumetric measurements were performed using a semiautomated tissue segmentation tool. A simple linear regression model to assess the predictors for parenchymal volume loss (PVL). A multivariable linear regression model was used to evaluate the association between PVL and warm ischemia time (WIT), controlling for other factors.

RESULTS

Mean WIT was 12.09 ± 4.40 minutes and the mean percentage decrease in the volume of the operated kidney was 16.99 ± 13.49%. WIT (β = 1.24, P < 0.001) and tumor complexity (simple vs. intermediate, β = 0.06, P = 0.984; simple vs. high, β = 11.62,P = 0.007) were associated with PVL. A 1 minute increase in WIT was associated with an increase in the percentage volume loss in the operated kidney by 1.38% (β = 1.20, P < 0.001). Patients with high tumor complexity (β = 11.17, P = 0.009) had a significantly higher percentage volume loss compared to patients with simple tumor complexity. Ipsilateral PVL (β = -0.35, P = 0.015) and male gender (β = -9.89, P = 0.021) were associated with change in eGFR. After adjusting for confounders, % volume loss (β = -0.32, P < 0.001) remained a significant predictor for contralateral hypertrophy.

CONCLUSION

Tumor complexity results in higher WIT and increased PVL as measured by volumetric segmentation. PVL is a key factor associated with functional outcome, and is directly linked to WIT. Increased PVL is also associated with decreased contralateral hypertrophy. Prospective studies with larger samples sizes will be required to validate our findings.

Assessment of Advanced Perioperative Outcomes to Identify the True Learning Curve of Robotic-assisted Partial Nephrectomy

OBJECTIVES

To evaluate the learning curve of robotic-assisted partial nephrectomy as it pertains to operative time (OT) and advanced perioperative variables such as achievement of trifecta, postoperative complications, 30-day readmission rates (RR), warm ischemia time (WIT), and functional volume loss (FVL).

METHODS

We evaluated 418 consecutive robotic-assisted partial nephrectomy performed by a single surgeon between February 2008 and April 2019. Multivariable log-log regression models were used to evaluate the associations between case number and continuous outcomes (OT, WIT, and FVL). Multivariable logistic regression models were used to evaluate the association of case number with dichotomous outcomes (trifecta, postoperative complications, RR).

RESULTS

Among the 406 eligible patients included in the study, 252 (62.1%) were male, median age was 63 years (range, 22-84), and median body mass index was 29 kg/m² (interquartile range 26-33). Surgeon experience was associated with shorter OT (-2.5% per 50% increase in case number; 95% confidence interval; P <.001) and plateaus around 77 cases performed. There was slight improvement with trifecta (odds ratio [per 50% increase in cases] = 1.08; 95% confidence interval) and the plateau was also at 77 cases, however, this was not statistically significant (P = .086). We did not find statistically significant associations of surgeon experience with FVL (P = .77), postoperative complications (P = .74), WIT (P = .73), or 30-day RR (P = .33).

CONCLUSION

There does not appear to be a relationship between surgical experience and grade 3 or higher postoperative complications, 30-day RR, WIT, or FVL. Trifecta outcomes and maximum OT performance appear to be optimized at approximately 77 cases.

Impact of short warm ischemic time on longitudinal kidney function and survival rate after partial nephrectomy for renal cell carcinoma in patients with pre-existing chronic kidney disease stage III: A multi-institutional propensity score-matched study

PURPOSE

It remains unclear whether a short warm ischemic time (WIT) improves long-term renal function after partial nephrectomy (PN) for patients with pre-existing chronic kidney disease (CKD). We evaluated renal function after PN according to WIT duration in patients with stage III CKD.

MATERIALS AND METHODS

We identified 277 patients with stage III CKD who underwent PN during 2004-2017. Propensity score matching was used to created two matched groups of patients: Group A (WIT of <25 min) and Group B (WIT of ≥25 min). The outcomes of interest were longitudinal kidney function change, new-onset stage IV CKD (eGFR <30 mL/min/1.73 m²) and overall survival.

RESULTS

The two matched groups contained 85 patients each. The median follow-up durations were 49 months in Group A and 42 months in Group B. The median pre-treatment eGFRs were 52.4 mL/min/1.73 m² in Group A and 52.6 mL/min/1.73 m² in Group B. There were no differences in kidney function between the two groups throughout the follow-up period (P > 0.05). The 5-year rates of new-onset stage IV CKD were not significantly different between Group A and Group B (8.2% vs. 7.1%), with no significant difference in the risk of developing stage IV CKD in Group A (vs. group B, hazard ratio: 0.527, 95% confidence interval: 0.183-1.521; P = 0.236). The 5-year overall survival rates were 90.3% for Group A and 96.2% for Group B (P = 0.549).

CONCLUSIONS

A short WIT was not associated with better postoperative kidney function or survival after PN in patients with stage III CKD.

Renal Volume Loss During Partial Nephrectomy Due to Resected Healthy Parenchyma: A Tool for Quick Estimation

Purpose: Our objective is to evaluate a technique for estimating the amount of healthy margin resected during partial nephrectomy (PN). Materials and Methods: The resected healthy margin volume was determined by planimetry (gold standard), which was performed in a prospective manner on 30 freshly resected renal masses by cross-sectional slicing every ∼5 mm. A single cross-sectional slice containing the largest tumor diameter (bivalved tumor) was chosen to build a model for estimating the amount of healthy kidney removed. This single-slice technique was then applied to a second series of patients (n = 39) status post PN. Three-dimensional models were created using pre- and postoperative CT scans to determine the overall volume loss following PN. Results: The median (range) for tumor diameter and tumor volume was 3.2 cm (1-6.1) and 10.7 cm³ (0.5-101.9), respectively, for the 30 PN specimens used to build the single-slice estimation equation. The median (range) healthy margin volume calculated by planimetry and single slice technique was 9.0 cm³ (1.0-22.1) and 7.8 cm³ (1.0-31.0), respectively (p = 0.37). The Pearson correlation was 0.84, and the median (range) percent difference between the planimetry and single slice techniques was -0.5% (-39% to 57%). For the 39 PN patients, the median (range) total renal volume loss, 25.8 cm³ (3-79), was significantly greater than the volume of healthy margin removed during resection, 5.7 cm³ (1-22), p < 0.001. Conclusions: The healthy margin resected during PN differs widely and can be estimated from a single cross-section. The healthy margin resected accounted for <50% of the total volume loss seen during PN.

The Use of Tissue Adhesive for Tumor Bed Closure during Partial Nephrectomy is Associated with Reduced Devascularized Functional Volume Loss

Objectives

To quantitatively compare the functional renal volume loss, following nephron sparing surgery (NSS) between patients in whom tumor bed closure was done by biological tissue adhesive and those who were managed by standard suture technique.

Methods

From our institutional NSS database we retrospectively collected patients who had two sequential quantitative single-photon emission computed tomography of ^99mTc-dimercaptosuccinic acid uptake studies, the first study immediately before surgery and the second one 3-6 months following surgery. The study group included 69 patients: 26 (37.7%) patients in the sealant group (BioGlue®) and 43 (62.3%) patients in the standard suture group.

Results

No statistically significant differences were noted in the baseline clinical and pathological characteristics of the studied groups. However, there were several statistically significant differences in operative variables: patients in the suture group had larger amount of blood loss (3-fold), longer ischemia time (26.6 vs. 21 minutes,) and slightly longer operation time. Patients in whom tumor bed was closed by sutures had nearly 3-fold higher parenchymal loss compared to patients managed by sealant (26.28 vs. 8.92 ml, p = 0.048).

Conclusions

The use of tissue sealant during tumor bed reconstruction is associated with reduced devascularized parenchymal mass loss and should be considered among modifiable surgical factors during NSS.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Approach for Renal Tumors With Low Nephrometry Score Through Unclamped Sutureless Laparoscopic Enucleation Technique: Functional and Oncologic Outcomes

PURPOSE

We report an unclamped sutureless laparoscopic simple enucleation (LSE) technique for renal tumors with low nephrometry score and analyze complication rates as well as functional and oncologic outcomes.

PATIENTS AND METHODS

We reviewed the data of 143 consecutive patients who underwent sutureless laparoscopic tumor enucleation with zero ischemia by a single experienced laparoscopic surgeon. The inclusion criteria for LSE with zero ischemia were tumor size ≤ 5 cm and RENAL nephrometry score of 4 to 6. The following data were collected: age, gender, body mass index, tumor side, renal function, tumor characteristics, American Society of Anesthesiologists score, operative time, positive surgical margins, estimated blood loss, and surgical complications.

RESULTS

The median RENAL score of patients was 4.7. Median tumor size was 2.7 cm. Conversion to open surgery and hilum vessels clamped were not necessary in any patient. There were no changes in postoperative creatinine values and estimated glomerular filtration rate. The median operation duration time was 78.2 minutes, and median estimated blood loss was 110.2 mL. The median hospital stay was 3.8 days. A total of 2.8% of the patients had positive surgical margins at pathologic examination. Of the 143 patients, 7% developed fever after surgery requiring an adequate antibiotic regimen, 1.4% developed postoperative bleeding requiring blood transfusions, and 0.7% had postoperative urinary leakage from the drainage requiring double-J stent position.

CONCLUSION

The unclamped sutureless LSE is a rational and safe approach to renal tumors with a low nephrometry score. This surgical technique does not increase the complication rate despite the reduction in parenchymal mass excised and the absence of hilar control.