Percutaneous ablation of the small renal mass-techniques and outcomes

Advances in Image-Guided Ablation Therapies for Solid Tumors

Image-guided solid tumor ablation methods have significantly advanced in their capability to target primary and metastatic tumors. These techniques involve noninvasive or percutaneous insertion of applicators to induce thermal, electrochemical, or mechanical stress on malignant tissue to cause tissue destruction and apoptosis of the tumor margins. Ablation offers substantially lower risks compared to traditional methods. Benefits include shorter recovery periods, reduced bleeding, and greater preservation of organ parenchyma compared to surgical intervention. Due to the reduced morbidity and mortality, image-guided tumor ablation offers new opportunities for treatment in cancer patients who are not candidates for resection. Currently, image-guided ablation techniques are utilized for treating primary and metastatic tumors in various organs with both curative and palliative intent, including the liver, pancreas, kidneys, thyroid, parathyroid, prostate, lung, breast, bone, and soft tissue. The invention of new equipment and techniques is expanding the criteria of eligible patients for therapy, as now larger and more high-risk tumors near critical structures can be ablated. This article provides an overview of the different imaging modalities, noninvasive, and percutaneous ablation techniques available and discusses their applications and associated complications across various organs.

Ablative Treatments for Small Renal Masses and Management of Recurrences: A Comprehensive Review

This review focuses on ablative techniques for small renal masses (SRMs), including radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), and irreversible electroporation (IRE), and discusses recurrence management. Through an extensive literature review, we outline the procedures, outcomes, and follow-up strategies associated with each ablative method. The review provides a detailed examination of these techniques-RFA, CA, MWA, and IRE-elucidating their respective outcomes. Recurrence rates vary among them, with RFA and CA showing comparable rates, MWA demonstrating favorable short-term results, and IRE exhibiting promise in experimental stages. For managing recurrences, various strategies are considered, including active surveillance, re-ablation, or salvage surgery. Surveillance is preferred post-RFA and post-CA, due to slow SRM growth, while re-ablation, particularly with RFA and CA, is deemed feasible without additional complications. Salvage surgery emerges as a viable option for larger or resistant tumors. While ablative techniques offer short-term results comparable to surgery, further research is essential to understand their long-term effects fully. Decisions concerning recurrence management should consider individual and tumor-specific factors. Imaging, notably contrast-enhanced ultrasounds, plays a pivotal role in assessing treatment success, emphasizing the necessity of a multidisciplinary approach for optimal outcomes. The lack of randomized trials highlights the need for further research.

Percutaneous Cryoablation of Recurrent or Oligometastatic Tumors in Thoracoabdominal Soft Tissues: Safety, Effectiveness, and Technical Aspects

PURPOSE

To assess the effectiveness and safety of cryoablation (CRA) for the treatment of recurrent or oligometastatic solid tumors located in the thoracoabdominal soft tissues.

MATERIALS AND METHODS

Twenty-two percutaneous CRA procedures performed in 19 patients to treat recurrent or oligometastatic tumors in thoracoabdominal soft tissue were retrospectively examined. All procedures were performed between January 2015 and June 2021 under ultrasound and computed tomography (CT) guidance, and the most complex procedures were performed with CT-based navigation systems. The histology of the primary tumors included colorectal adenocarcinoma, squamous cell lung carcinoma, pancreatic adenocarcinoma, renal cell carcinoma, and hepatocellular carcinoma. Adverse events, technical success, and local tumor control were analyzed.

RESULTS

The mean age of the patients was 66.5 years, with a mean tumor size of 24.8 mm. The mean time of the procedures was 68 minutes, with a mean number of 2.5 cryoprobes used. Hydrodissection was performed in 63% of the procedures to protect the surrounding anatomical structures. The mean size of the ice ball, measured on axial CT scans at the end of the procedures, was 43.5 mm. No severe adverse events were observed. Technical success was achieved in all cases. Three patients experienced local tumor progression (2 residual disease and 1 recurrence), which were successfully treated with a second CRA procedure.

CONCLUSIONS

Percutaneous CRA is a safe and effective therapy in selected cases of recurrent or oligometastatic tumors in the thoracoabdominal soft tissues.

Urine Molecular Biomarkers for Detection and Follow-Up of Small Renal Masses

Active surveillance (AS) is the best strategy for small renal masses (SRMs) management; however, reliable methods for early detection and disease aggressiveness prediction are urgently needed. The aim of the present study was to validate DNA methylation biomarkers for non-invasive SRM detection and prognosis. The levels of methylated genes TFAP2B, TAC1, PCDH8, ZNF677, FLRT2, and FBN2 were evaluated in 165 serial urine samples prospectively collected from 39 patients diagnosed with SRM, specifically renal cell carcinoma (RCC), before and during the AS via quantitative methylation-specific polymerase chain reaction. Voided urine samples from 92 asymptomatic volunteers were used as the control. Significantly higher methylated TFAP2B, TAC1, PCDH8, ZNF677, and FLRT2 levels and/or frequencies were detected in SRM patients' urine samples as compared to the control. The highest diagnostic power (AUC = 0.74) was observed for the four biomarkers panel with 92% sensitivity and 52% specificity. Methylated PCDH8 level positively correlated with SRM size at diagnosis, while TFAP2B had the opposite effect and was related to SRM progression. To sum up, SRMs contribute significantly to the amount of methylated DNA detectable in urine, which might be used for very early RCC detection. Moreover, PCDH8 and TFAP2B methylation have the potential to be prognostic biomarkers for SRMs.

Perithyroidal hemorrhage caused by hydrodissection during radiofrequency ablation for benign thyroid nodules: Two case reports

BACKGROUND

Hydrodissection is a widely used technique during radiofrequency ablation (RFA) for benign thyroid nodules. Although it could effectively avoid thermal injury to the surrounding critical structures and achieve complete treatment, routine operation of the remaining needle could cause perithyroidal hemorrhage. In this report, we present 2 cases of perithyroidal hemorrhage during RFA caused by a hydrodissection needle, which have not been reported before.

CASE SUMMARY

A 21-year-old female and a 45-year-old male were admitted for RFA for benign thyroid nodules. Considering that their nodules were adjacent to the recurrent laryngeal nerve, the needle used for hydrodissection was placed and remained between the dorsal capsule of the lateral lobe and the recurrent laryngeal nerve. During the procedure, active bleeding near the needle appeared on ultrasonography (US). Although moderate pressure was quickly applied to the neck for several minutes, contrast-enhanced US (CEUS) still showed an active hemorrhage. A radiofrequency electrode was placed at the bleeding point under the guidance of CEUS to stop the bleeding, and the procedure was finally confirmed to be successful by CEUS, without other complications.

CONCLUSION

Hydrodissection during RFA of benign thyroid nodules was associated with a risk of perithyroidal hemorrhage. The timely recognition of this acute hemorrhage could help in the timely control of the bleeding, and CEUS-guided ablation of the bleeding point could be useful.

Comparison of the Results of Therapy for cT1 Renal Carcinoma with Nephron-Sparing Surgery (NSS) vs. Percutaneous Thermal Ablation (TA)

Implementation of ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI) into abdominal cavity diagnostics enabled early detection of cT1 graded renal cancers. According to European Association of Urology (EAU) and Polish urological Association (PUA) recommended method of treatment is sparing resection of renal parenchyma with tumour—nephron-sparing surgery (NSS). In selected cases other methods such as thermal ablation (TA) or cryoablation can be introduced /1/. Objectives: To evaluate the results of treatment of cT1 renal tumours with the use of NSS and TA methods. Material and methods: 140 patients with cT1 renal carcinoma were treated in 2nd Department of Urology of Medical University of Lodz between 2014 and 2017. Neuron-sparing surgery was performed in 56 cases (40%), while percutane-ous thermal ablation (TA) in 84 cases (60%). Demographic data, clinical data (lab results, Charlson index), nephrometry data (tumour size, location, R.E.N.A.L. score) post-operative data (Clavien-Dindo classifica-tion) were investigated. Histopathology results, Fuhrman malignancy grading, as total three-year survival of patients were evaluated. The following methods were used for statistical evaluation: Chi2, Fisher, W Shapiro-Wilk, U Mann-Whitney tests, Kaplan-Meier’s curve and Cox model. The results were displayed in a form of median and upper and lower quartile values (25–75%). Results: No statistical differences in gender nor left/right kidney location were observed. Patients, who underwent TA were at average 10 years older and had multiple comorbidities (median age for TA was 79, for NSS 68; median Charlson index for TA was 5 and for NSS was 3). TA patients had lesser haematological values (Hb, Ht). R.E.N.A.L. scoring demonstrated comparable nephrometry in both groups. NSS procedure was open laparotomy without temporary clamping of renal vessels. Surgical margins of resected tumours were negative. TA was performed with Cool-Tip Covidienequipment with the use of Cluster electrode and was ultraso-nography-guided. Post-treatment complications evaluated with the use of Clavien-Dindo classification were slightly more frequent for NSS method. Patients after NSS were discharged at average after 8.5 days and after TA after 3 days. Histopathological type and Fuhrman malignancy grading were comparable in both groups. TA treated patients’ death risk was 9-fold of that observed in NSS treated patients. There was 1 death for each group in perioperative period. Conclusion: 1. NSS was associated with slightly higher side effect rate but resulted in prolonged survival. 2. TA was applied to elderly patients with comorbidities. Despite less invasive treatment this group had poorer/reduced survival. 3. Charlson Comorbidity Index (CCI) and the treatment method were relevant survival factors in patients treated due to cT1 renal cancer tumours.

Renal biopsies performed before versus during ablation of T1 renal tumors: implications for prevention of overtreatment and follow-up

Purpose

To assess the difference between renal mass biopsy (RMB) performed either before or during the ablation procedure.

Methods

A retrospective multicenter study was performed in patients with a cT1 renal mass treated with ablation between January 2007 and July 2019, including a search in the national pathology database for patients with a RMB planned for ablation. Patient and tumor characteristics and information on malignant, benign, and non-diagnostic biopsy results were collected to establish rates of overtreatment and number of ablations avoided in case of benign or non-diagnostic histology.

Results

RMB was performed in 714 patients, of which 231 patients received biopsy before planned ablation, and 483 patients at the time of ablation. Pathology results before ablation were malignant in 63% (145/231), benign in 20% (46/231) and non-diagnostic in 17% (40/231). Pathology results at the time of ablation were malignant in 67.5% (326/483), benign in 16.8% (81/483) and non-diagnostic in 15.7% (76/483), leading to a total of 32.5% of ablation of benign or non-diagnostic lesions. Of the patients with a benign biopsy obtained before ablation, 80.4% (37/46) chose not to undergo ablation. Patients with inconclusive biopsy before planned ablation chose an informed individualized approach including ablation, repeated biopsy, or no intervention in 56%, 34% and 10%.

Conclusion

This study emphasizes the importance of obtaining a biopsy prior to the ablation procedure in a separate session to lower the rate of potentially unnecessary ablations.

Stereotactic Body Radiotherapy for Stage I Renal Cell Carcinoma: National Treatment Trends and Outcomes Compared to Partial Nephrectomy and Thermal Ablation

PURPOSE

To assess use of stereotactic body radiotherapy (SBRT) for stage I renal cell carcinoma (RCC) and compare outcomes with thermal ablation and partial nephrectomy (PN).

MATERIALS AND METHODS

The 2004-2015 National Cancer Database was investigated for histopathologically proven stage I RCC treated with PN, cryoablation, radiofrequency (RF) or microwave (MW) ablation, or SBRT. Patients were propensity score-matched to account for potential confounders, including patient age, sex, race, comorbidities, tumor size, histology, grade, tumor sequence, administration of systemic therapy, treatment in academic vs nonacademic centers, treatment location, and year of diagnosis. Overall survival (OS) was evaluated with Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models.

RESULTS

A total of 91,965 patients were identified (SBRT, n = 174; PN, n = 82,913; cryoablation, n = 5,446; RF/MW ablation, n = 3,432). Stage I patients who received SBRT tended to be older women with few comorbidities treated at nonacademic centers in New England states. After propensity score matching, a cohort of 636 patients was obtained with well-balanced confounders between treatment groups. In the matched cohort, OS after SBRT was inferior to OS after PN and thermal ablation (PN vs SBRT, hazard ratio [HR] = 0.29, 95% confidence interval [CI] 0.19-0.46, P < .001; cryoablation vs SBRT, HR = 0.40, 95% CI 0.26-0.60, P < .001; RF/MW ablation vs SBRT, HR = 0.46, 95% CI 0.31-0.67, P < .001). Compared with PN, neither cryoablation nor RF/MW ablation showed significant difference in OS (cryoablation vs PN, HR = 1.35, 95% CI 0.80-2.28, P = .258; RF/MW ablation vs PN, HR = 0.64, 95% CI 0.95-2.55, P = .079).

CONCLUSIONS

Current SBRT protocols show lower OS compared with thermal ablation and PN, whereas thermal ablation and PN demonstrate comparable outcomes.

Active surveillance and focal ablation for small renal masses: a better solution for comorbid patients

The natural history of small renal masses (SRM) is still not well understood and they are frequently incidentally diagnosed in elderly patients. Therefore, there is a need for less invasive options sparing the patient from the side-effects related to conventional surgical treatment. PubMed and Medline database search was performed to look for new findings on active surveillance and focal therapy for SRM. Sixty-one articles published between 2002 and 2018 were selected for the purpose of the review. There is growing evidence confirming the safety of active surveillance in patients at surgical risk and there appears to be a satisfactory intermediate-term outcome of focal treatment of SRM. In the group of elderly patients with a decreased life expectancy active surveillance appears to be the most appropriate approach. The future of minimally invasive therapy appears bright, especially with the improvement of new imaging modalities.

Pneumodissection during Percutaneous Renal Ablation Resulting in Air Embolism: Percutaneous Management and a Review of the Literature

Percutaneous renal ablation is a nephron-sparing approach for selected patients with renal cell carcinoma. Common complications include hemorrhage, injury to the urinary collecting system, and abscess formation. The purpose of this article is to present a case of vascular air embolism as a complication of pneumodissection performed during percutaneous ablation of renal cell carcinoma, discuss its successful percutaneous management, review common complications of renal ablation, and outline steps physicians can take to lessen these complications.

Percutaneous irreversible electroporation for the treatment of small renal masses: The first Canadian case series

INTRODUCTION

Irreversible electroporation (IRE) is a novel technology used in the minimally invasive treatment of small solid organ tumours. Currently, there is a paucity of literature studying treatment of small renal masses (SRMs) with IRE. Our pilot study is the first case series in Canada to use IRE in the treatment of SRMs.

METHODS

This retrospective cohort pilot study includes five patients (three females and two males) who presented with a SRM that was deemed not amendable to any other treatment than a radical nephrectomy or IRE. The IRE procedures were carried out by an interventional radiologist in conjunction with a urologist using the Angiodynamics NanoKnife IRE device.

RESULTS

Mean tumour size was 28 mm (range 18-39), with a mean R.E.N.A.L. nephrometry score of 8.4±0.55. Over a mean followup of 22.8 months (range 14-31), four out of the five patients did not have a radiological recurrence. No adverse events were reported after the five IRE procedures. Renal function was stable post-IRE, with no to negligible decreases in estimated glomerular filtration rate detected (range +2 to -13 mL/min/1.73 m²).

CONCLUSIONS

Our pilot study demonstrates that renal percutaneous IRE is safe to use in the context of challenging-to-treat SRMs. Early radiological and renal function outcomes are encouraging, but further study is required to assess oncological success. The small sample size, retrospective nature of the study, relatively short followup, and the lack of routine renal biopsy to confirm malignancy are the major limitations noted.

Trans-Arterial Embolization of Renal Cell Carcinoma prior to Percutaneous Ablation: Technical Aspects, Institutional Experience, and Brief Review of the Literature

This report describes the technical aspects of trans-arterial embolization (TAE) of renal cell carcinoma prior to percutaneous ablation. All patients (n = 11) had a single renal mass (mean tumor diameter = 50.2 mm; range: 28-84 mm). Selective TAE was performed via the common femoral artery. Embolic materials included: particles alone (n = 4), coils alone (n = 1), particles + ethiodized oil (n = 2), particles + coils (n = 1), ethiodized oil + ethanol (n = 2), and particles + ethanol (n = 1). All embolizations were technically successful and no complications have been reported. After embolization, 10 patients underwent cryoablation while 1 patient underwent microwave ablation. Ablations were technically successful in 10 of the 11 patients. Only 3 minor complications were identified but none required treatment. No adverse effect on the patient's glomerular filtration rate was seen from the additional procedure (p = 0.84). TAE of renal cell carcinoma prior to percutaneous ablation is safe and technically-feasible.

Efficacy of antegrade and retrograde warm saline pyeloperfusion during renal cryoablation for ureteral preservation

Objective

Cryoablation of renal tumors adjacent to the ureter or pelvicalyceal system carries risks for thermal injury of the collecting system. Although cold antegrade perfusion has been described for radiofrequency ablation, warm saline perfusion for renal cryoablation has not been well-characterized. The purpose of this study was to determine the safety and feasibility of antegrade and retrograde warm saline perfusions during percutaneous renal cryoablation.

Material and methods

A retrospective review was performed on 136 patients treated with percutaneous renal cryoablation at a single academic institution between 2009 and 2015. Six patients undergoing antegrade (n=3) or retrograde (n=3) warm saline perfusion for protection of the collecting system were identified. Warm saline was perfused through a 4 French nephrostomy tube in the antegrade technique and through a 6 French end-hole catheter in the retrograde technique. Outcome measures were tumor recurrence rates, success of urothelial preservation, hospital stay, blood loss and procedural time.

Results

Four tumors were in the lower pole and two tumors in the middle pole. The mean distance from tumor to ureter was 6.8 mm (0.8-11.5 mm) and no patient developed ureteral stricture. There was no tumor recurrence at a median follow-up of 37.3 months (7-65). The median procedural time was 3 hours and 13 minutes. One patient in each group developed minor complications (Clavien I and II) and there were no major complications.

Conclusion

This study demonstrates the feasibility of antegrade and retrograde warm saline perfusion for ureteral preservation during cryoablation, without compromising oncologic outcomes.

Management of Small Renal Masses

With the ubiquitous use of cross-sectional abdominal imaging in recent years, the incidence of small renal masses (SRMs) has increased, and the evaluation and management of SRMs have become important clinical issues. Diagnosing a mass in the early stages theoretically allows for high rates of cure but simultaneously risks overtreatment. In the past 20 years, surgical treatment of SRMs has transitioned from radical nephrectomy for all renal tumors, regardless of size, to elective partial nephrectomy whenever technically feasible. Additionally, newer approaches, including renal mass biopsy, active surveillance for select patients, and renal mass ablation, have been increasingly used. In this chapter, we review the current evidence-based papers covering aspects of the diagnosis and management of SRMs.

[Percutaneous renal ablation: Pre-, per-, post-interventional evaluation modalities and adapted management]

OBJECTIVES

Ablative treatment (AT) rise is foreseen, validation of steps to insure good proceedings is needed. By looking over the process of the patient, this study evaluates the requirements and choices needed in every step of the management.

METHODS

We searched MEDLINE^®, Embase^®, using (MeSH) words and we looked for all the studies. Investigators graded the strength of evidence in terms of methodology, language and relevance.

RESULTS

Explanations of AT proposal rather than partial nephrectomy or surveillance have to be discussed in a consultation shared by urologist and interventional radiologist. Per-procedure choices depend on predictable ballistic difficulties. High volume, proximity of the hilum or of a risky organ are in favor of general anesthesia, cryotherapy and computed tomography/magnetic resonance imaging (CT/MRI). Percutaneous approach should be privileged, as it seems as effective as the laparoscopic approach. Early and delayed complications have to be treated both by urologist and radiologist. Surveillance by CT/MRI insure of the lack of contrast-enhanced in the treated area. Patients and tumors criteria, in case of incomplete treatment or recurrence, are the key of the appropriate treatment: surgery, second session of AT, surveillance.

CONCLUSION

AT treatments require patient's comprehension, excellent coordination of the partnership between urologist and radiologist and relevant choices during intervention.

Focal ablation therapy for renal cancer in the era of active surveillance and minimally invasive partial nephrectomy

Partial nephrectomy is the optimal surgical approach in the management of small renal masses (SRMs). Focal ablation therapy has an established role in the modern management of SRMs, especially in elderly patients and those with comorbidities. Percutaneous ablation avoids general anaesthesia and laparoscopic ablation can avoid excessive dissection; hence, these techniques can be suitable for patients who are not ideal surgical candidates. Several ablation modalities exist, of which radiofrequency ablation and cryoablation are most widely applied and for which safety and oncological efficacy approach equivalency to partial nephrectomy. Data supporting efficacy and safety of ablation techniques continue to mature, but they originate in institutional case series that are confounded by cohort heterogeneity, selection bias, and lack of long-term follow-up periods. Image guidance and surveillance protocols after ablation vary and no consensus has been established. The importance of SRM biopsy, its optimal timing, the type of biopsy used, and its role in treatment selection continue to be debated. As safety data for active surveillance and experience with minimally invasive partial nephrectomy are expanding, the role of focal ablation therapy in the treatment of patients with SRMs requires continued evaluation.

Percutaneous irreversible electroporation of a renal tumor: Anesthetic management

Percutaneous irreversible electroporation (IRE) is a novel tumour ablation method. The application of short and high-voltage electrical pulses to the target lesion induces alterations in cell membrane permeability, finally causing tumour cell death. The extremely high-voltage that is needed in this technique requires the surveillance and management of an experienced anaesthesiologist, as it involves a significant risk of complications, such as cardiac arrhythmias or seizures. The case is presented of a 66 year-old patient diagnosed with a renal adenocarcinoma, and who received without intention-to-cure IRE under general anaesthesia. This case represents the first time this type of technique is used in Spain.

Indications for biopsy and the current status of focal therapy for renal tumours

The increased detection of small renal masses (SRMs) has focused attention on their uncertain natural history. The development of treatment alternatives and the discovery of biologically targeted drugs have also raised interest. Renal mass biopsies (RMBs) have a crucial role as they provide the pathological, molecular and genetic information needed to classify these lesions and guide clinical management. The improved accuracy has improved our knowledge of the behaviour of different tumour histologies and opened the potential for risk-adapted individualized treatment approaches. To date, studies have demonstrated that percutaneous ablation is an effective therapy with acceptable outcomes and low risk in the appropriate clinical setting. Although partial nephrectomy (PN) is still considered the standard treatment for SRM, percutaneous ablation is increasingly being performed and if long-term efficacy is sustained, it may have a wider application for SRMs after biopsy characterization.

Evaluation and Management of the Geriatric Urologic Oncology Patient

The geriatric population presents a unique set of challenges in urologic oncology. In addition to the known natural history of disease, providers must also consider patient factors such as functional and nutritional status, comorbidities and social support when determining the treatment plan. The development of frailty measures and biomarkers to estimate surgical risk shows promise, with several assessment tools predictive of surgical complications. Decreased dependence on chronologic age is important when assessing surgical fitness, as age cutoffs prevent appropriate treatment of many elderly patients who would benefit from surgery. Within bladder, kidney and prostate cancers, continued refinement of surgical techniques offers a broader array of options for the geriatric patient than previously available.

Evaluation of the charges, safety, and mortality of percutaneous renal thermal ablation using the nationwide inpatient sample

PURPOSE

To perform a national analysis of safety, charges, complications, and mortality of percutaneous image-guided renal thermal ablation and compare outcomes by hospital volume.

MATERIALS AND METHODS

Using the Nationwide Inpatient Sample, trends in the proportion of inpatient percutaneous renal thermal ablation procedures performed at high-volume centers in the United States from 2007-2011 were evaluated. In-hospital mortality, discharge to long-term care facility, length of stay, hospitalization charges, and postoperative complications were compared between high-volume and low-volume ablation centers. High volume was set at the 90th percentile for renal thermal ablation volume, which equated to seven or more patients per year. A multivariate logistic regression analysis adjusting for hospital volume, age, sex, Charlson Comorbidity Index, obesity, race, and insurance status was performed to analyze the influence of hospital volume on the above-listed outcomes.

RESULTS

This study included 874 patients. The number of hospitals ranged from 59-77 depending on year. Overall, 328 patients (37.5%) were treated at high-volume ablation centers. The proportion of patients treated at high-volume centers decreased from 42.0% in 2007-2009 to 28.5% in 2010-2011. High-volume hospitals also performed significantly more partial nephrectomies than low-volume hospitals. On multivariate logistic regression analysis, increasing hospital volume was associated with lower odds of in-hospital mortality (odds ratio [OR] = 0.31, 95% confidence interval [CI] = 0.02-0.95) and lower odds of discharge to a long-term care facility (OR = 0.00, 95% CI = 0.00-0.66). Increasing hospital volume was also associated with lower odds of blood transfusion (OR = 0.84, 95% CI = 0.72-0.94). Length of stay decreased with increasing hospital volume (P = .03).

CONCLUSIONS

Patient safety may be maximized when renal ablation is performed at high-volume centers as a result of both greater procedural experience and potentially multidisciplinary triage and periprocedural management.

Laparoscopic renal cryoablation

In light of evidence linking radical nephrectomy and consequent suboptimal renal function to adverse cardiovascular events and increased mortality, research into nephron-sparing techniques for renal masses widely expanded in the past two decades. The American Urological Association (AUA) guidelines now explicitly list partial nephrectomy as the standard of care for the management of T1a renal tumors. Because of the increasing utilization of cross-sectional imaging, up to 70% of newly detected renal masses are stage T1a, making them more amenable to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. Cryosurgery has emerged as a leading option for renal ablation, and compared with surgical techniques it offers benefits in preserving renal function with fewer complications, shorter hospitalization times, and allows for quicker convalescence. A mature dataset exists at this time, with intermediate and long-term follow-up data available. Cryosurgical recommendations as a first-line therapy are made at this time in limited populations, including elderly patients, patients with multiple comorbidities, and those with a solitary kidney. As more data emerge on oncologic efficacy, and technical experience and the technology continue to improve, the application of this modality will likely be extended in future treatment guidelines.