Laparoscopic Cryoablation Research Articles

Comparison of Robot-Assisted Laparoscopic Partial Nephrectomy with Laparoscopic Cryoablation in the Treatment of Localised Renal Tumours: A Propensity Score-Matched Comparison of Long-Term Outcomes.

Preserving renal function and controlling oncological outcomes are pertinent when managing renal neoplasms. Cryoablation is the recommended treatment only for clinical T1a stage renal tumour. Here, we compared the outcomes of robot-assisted laparoscopic partial nephrectomy (RaPN) and laparoscopic cryoablation (LCA) in the treatment of patients with localised T1-T2 renal tumours. Overall, 86 patients who received RaPN and 78 patients underwent LCA were included in this study. The intraoperative, postoperative, and oncological outcomes in the LCA group were non-inferior to the RaPN group. Moreover, LCA demonstrated shorter operative time (267.45 ± 104.53 min vs. 138.56 ± 45.28 min, p < 0.001), lower blood loss (300.56 ± 360.73 mL vs. 30.73 ± 50.31 mL, p < 0.001), and slight renal function deterioration because of the reduced invasiveness, without compromising on the oncological outcomes.

Laparoscopic cryoablation for small renal masses: Oncological outcomes at 5-year follow-up

ABSTRACT Objective: To evaluate the oncological outcome at 5-year follow-up after laparoscopic cryoablation (LCA) for small renal masses (SRMs), as there is an increasing interest in ablative therapy for cT1a renal tumours due to the rising incidence of SRMs, the trend towards minimally invasive nephron-sparing treatments, and the ageing population. Patients and methods: Between 2004 and 2015, 233 consecutive LCA were performed in 219 patients for SRMs at two referral centres. We only included those patients with ≥5 years of follow-up (n = 165) in a prospectively maintained database. A descriptive analysis was conducted for pre-, peri- and postoperative characteristics. A Kaplan–Meier analysis assessed overall (OS), disease-specific (DSS), and recurrence-free survival (RFS). Results: The median (interquartile range [IQR]) age of our patient cohort was 68 (60.5–76) years. The median (IQR) body mass index was 26.2 (23.8–29) kg/m2, and the median (IQR) Charlson Comorbidity Index score corrected for age was 4 (2.5–6). The median (IQR) tumour diameter was 28 (21–33) mm. In all, 15% developed a complication in the first 30 days after LCA, of which 1% had a major complication (Clavien–Dindo Grade ≥III). The median (IQR) preoperative estimated glomerular filtration rate (eGFR) was 82.5 (65–93.75) mL/min/1.73 m2. The median eGFR decreased by 16.4% and 15.2% at the 3-month and 5-year follow-up, respectively. Persistence was found in 1%, local recurrence in 2%, and systemic progression in 4%. The OS, DSS, and RFS were 74%, 96.9% and 95.4%, respectively. Conclusion: LCA is a safe and effective treatment for SRMs in selected cases and shows good oncological outcomes after 5 years of follow-up, with only 1% developing a major complication.

Combined Laparoscopic and CT Monitoring of the Ice-Ball Margin during Cryoablation for Renal Cell Carcinoma Associated with von Hippel-Lindau Disease: First Case.

We report a 47-year-old Japanese female with 10 previous treatments for multiple bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau disease. The 14-mm right lower pole renal tumor was in contact with the right ureter. Laparoscopic cryoablation was performed to protect the ureter wrapped with gauze. Computed tomography (CT) monitoring was used to confirm the precise ≥ 6 mm ice-ball margin. There was no local progression at 6-months post-surgery. The serum creatinine has been stable. This is apparently the first report of combined laparoscopic and CT monitoring of an ice-ball formation and its margin during cryoablation for RCC.

Acute Phase Response and Postprocedural Evaluation of Open and Laparoscopic Cryoablation Procedures in Porcine Pancreases.

Cryoablation is a potentially less invasive locoregional ablation modality. Although cryoablation has been used to treat malignancy in various organs, a limited application of this modality in the pancreas has been reported. Acute phase response assessments and postprocedural course evaluations of 2 experimental locoregional ablation methods were conducted. In one method, open and laparoscopic cryoablation of a porcine pancreas using an argon-helium gas-based cryoablation system and monitoring of tissue temperature during the procedure were performed. In the other method, open cryoablation of a porcine pancreas using liquid nitrogen was performed. The animals were evaluated postoperatively. The size of the cryolesion was larger in the second treatment than in the first. Laparoscopic cryoablation was associated with the formation of an iceball, which possibly affected the surrounding structures. The ablated region was adequately cooled with 10 minutes of freeze/repeat cycles. The area cooled to a temperature of less than -40°C was approximately half the size of the cryolesion in diameter. The swine used for the evaluation of the postprocedural course survived 3 weeks after the procedure with a temporal elevation of the serum lipase level. Cryoablation of the pancreas was experimentally practicable without severe complications under direct or laparoscopic vision.

599 - Laparoscopic cryoablation for small renal masses: Oncological outcomes at 5 year follow-up

Objective: To evaluate the oncological outcome at 5-year follow-up after laparoscopic cryoablation (LCA) for small renal masses (SRMs), as there is an increasing interest in ablative therapy for cT...

Single-institution analysis of ablations versus partial nephrectomies for small renal masses.

e17074 Background: Renal cell carcinoma (RCC) has the highest mortality rate of the genitourinary cancers with detection rising annually for small ( &lt; 4cm) renal masses (SRM). Nephron-sparing partial nephrectomy (PN) is recommended over other approaches such as ablations (Abl). This study aims to evaluate the outcomes and costs associated with treating patients with SRM RCC that undergo PN, laparoscopic cryoablation (lcryo), or various percutaneous ablations-cryoablation (pcryo), microwave (pmv), and radiofrequency (prf). Methods: A retrospective chart review of 295 patients that had either a PN or Abl from 2010-2019 at Beaumont Hospital- Royal Oak was performed. 189 patients with SRM were analyzed. Data collected included demographics, comorbidities, pathology, 30-day ED readmission, recurrence rate, and hospital-billed costs and charges. Data was analyzed using Mann-Whitney, chi-square, unpaired t-tests, Kruskal Wallis post-test, and Dunn’s multiple comparison test. Results: 133 patients with an index Abl (6 lcryo, 73 pcryo, 44 pmv, and 10 prf) and 56 patients with an index PN were analyzed. Mean tumor size for Abl (2.34cm; 90% biopsy-confirmed RCC) and PN (2.48cm; 87% histology confirmed RCC) was comparable. The populations undergoing PN or Abl were similar for both demographics and comorbidities except for age at index procedure (PN 58, Abl 71, p &lt; 0.01). Length of stay (LOS) following index procedure differed with an avg PN LOS = 2.74 days and Abl LOS 0.52 (p &lt; 0.01). 55% of PN patients presented to the ED within 30 days (38% readmitted) whereas only 8% of Abl patients did (42% readmitted)(p &lt; 0.01). The recurrence rate for PN compared to Abl was 23% to 14%, respectively (p = 0.14), with an average follow-up time of 4.95 years for PN and 2.78 years for Abl (p &lt; 0.01). Total hospital charge analysis showed PN being 1.57 the charge of all Abl types (p &lt; 0.01) while cost analysis demonstrated PN being more costly than Abl as a whole by 2.79x (p &lt; 0.01). When evaluating ablation subtypes, trends were noted lcryo being comparable to PN in both charge and cost while percutaneous interventions pmv, pcryo, and prf displayed lower charge and cost when compared to both PN and lcryo. Conclusions: With treatment decisions for SRM RCC are multifactorial, this single-site study demonstrated similar populations with comparable pathologies undergo both PN and Abl procedures. Complication and readmission rates differ between PN and Abl and consideration should be made for these variables as well as the costs associated with each procedure type when managing SRM RCC.

Evaluation of Three-Dimensional Printing-Assisted Laparoscopic Cryoablation of Small Renal Tumors: A Preliminary Report.

This study aimed to explore the security and feasibility of three-dimensional (3D) printing technology- assisted laparoscopic cryoablation to treat small renal tumors. Four patients recruited from our hospital from April 2016 to August 2017 underwent 3D printing technology-assisted laparoscopic cryoablation. Three-dimensional reconstruction technology was used to mimic cryoablation treatment before operations to determine the number of needles needed for the operation and the depth and angle required for needle insertion into the tumor to preserve nephron integrity. CT scans were used to assess the treatment's efficacy after operation during regular follow-up. The operation was performed successfully in all cases and all patients recovered without major complications. The operation times ranged from 106 to 118 minutes and blood loss ranged from 50 to 100 mL. The follow-up times were between 8-16 months and the mean time was 13.3 months. Follow-up surveys were conducted regularly based on a standard outpatient protocol. Results showed no abnormal reinforcing signals in cryoablation treated areas. 3D printing technology-assisted laparoscopic cryoablation is a feasible method for the treatment of renal tumors and may be a way to better preserve nephrons, especially in elderly patients and/or those with comorbidities.

PD08-04 EARLY POSTOPERATIVE COMPLICATIONS ASSOCIATED WITH LAPAROSCOPIC CRYOABLATION FOR RENAL MASS

INTRODUCTION AND OBJECTIVE:Laparoscopic Cryoablation (LC) is commonly indicated for anterior renal mass or those nearby vital structures. Reports describing early postoperative (postop) morbidity a...

Focal Ablative Therapy for Renal Cell Carcinoma in Transplant Allograft Kidneys

ObjectiveTo evaluate outcomes after focal ablative therapy for renal cell carcinoma (RCC) in transplant allograft kidneys. MethodsAfter institutional review board approval, patients with a history of RCC in a transplanted allograft kidney who underwent focal ablative therapy were identified. Complete chart reviews were performed and the relevant data were extracted for cumulative analysis. ResultsSix patients were treated with focal ablative therapy for RCC in a transplanted allograft kidney at our institutional between 2010 and 2017. Masses were diagnosed at a median of 8 years (range 1 month-8 years) after transplantation. Median mass size was 3 cm. Three patients were treated with microwave ablation, 1 with percutaneous irreversible electroporation, 1 with laparoscopic cryoablation, and 1 with open cryoablation. Median follow-up was 45 months (range 8-61 months). The median creatinine level was 1.65 before ablation and 1.58 1 year after ablation. No patients required dialysis after ablation. No patients developed local recurrence during the follow-up period. However, 1 patient developed lymph node metastases 4 years after ablation. Two patients died during follow-up of other causes. At the time of death both patients had functioning grafts. ConclusionFocal ablative therapies are a feasible, renal-sparing intervention for the management of RCC in renal allografts at intermediate-term follow-up.

Toward Semi-autonomous Cryoablation of Kidney Tumors via Model-Independent Deformable Tissue Manipulation Technique.

We present a novel semi-autonomous clinician-in-the-loop strategy to perform the laparoscopic cryoablation of small kidney tumors. To this end, we introduce a model-independent bimanual tissue manipulation technique. In this method, instead of controlling the robot, which inserts and steers the needle in the deformable tissue (DT), the cryoprobe is introduced to the tissue after accurate manipulation of a target point on the DT to the desired predefined insertion location of the probe. This technique can potentially reduce the risk of kidney fracture, which occurs due to the incorrect insertion of the probe within the kidney. The main challenge of this technique, however, is the unknown deformation behavior of the tissue during its manipulation. To tackle this issue, we proposed a novel real-time deformation estimation method and a vision-based optimization framework, which do not require prior knowledge about the tissue deformation and the intrinsic/extrinsic parameters of the vision system. To evaluate the performance of the proposed method using the da Vinci Research Kit, we performed experiments on a deformable phantom and an ex vivo lamb kidney and evaluated our method using novel manipulability measures. Experiments demonstrated successful real-time estimation of the deformation behavior of these DTs while manipulating them to the desired insertion location(s).

Cryoablation of renal cell carcinoma: six-year experience with 64 cases

Objective To summarize our clinical experience of cryoablation for renal cancer and to analyze the therapeutic indication, security, selection of cryoablation and outcomes. Methods Sixty-four patients suffered with T1a renal cell carcinoma were enrolled in this study from March 2012 to March 2018. Among them, 5 cases were senile patients(≥80 years), 5 cases complicated with other cancers, 3 cases complicated with renal insufficiency, 4 cases complicated with decompensated cirrhosis, 3 cases with bilateral renal cancer, 4 cases with solitary kidney cancer and 39 cases with some other complications. The preoperative serum creatinine level was(80.5±38.2)μmol/L. The patients underwent laparoscopic single-site (LESS) renal cryoablation, conventional laparoscopic renal cryoablation, or percutaneous image-guided cryoablation according to individual situation. Contrast-enhanced CT scan or MRI were used during the procedures and follow-up was performed. Results All operations were completed successfully and technical success was achieved as well in all cases. Blood transfusion was necessary for 2 cases because of hemorrhage.The mean diameter of the mass was (2.6±0.90)cm , the median volume of blood loss was 50ml(10-110 ml), and the mean operation time was(96.0±24.5)min. The median inpatient hospital stay was 3 d(1-6 d). In one case, digital subtraction angiography(DSA )embolization was performed due to hemorrhage after surgery. None of the other cases had intraoperative or postoperative complications. The serum creatinine level after surgery was not significantly decreased [postoperative (83.8±42.1) μmol/L, P=0.64]. The contrast-enhanced CT or MRI of the kidneys one week postoperatively showed uniform low density in all lesion areas, which represented complete ablation and regression of the tumor. All cases were followed up regularly. One case showed relapse at the 6th month follow-up and underwent cryoablation again. Another case, who was not regularly followed up, relapsed at 69th month after surgery. No relapse was observed in the other cases during the follow-up. Conclusions Renal cancer cryoablation is a safe, feasible and efficacious therapy for the patients who suffered from unresectable T1a renal cell carcinoma because of high surgical risk or multifocal lesions. Key words: Carcinoma, renal cell; Cryoablation; Laparoscopy; Imaging-guided

Small renal cell carcinoma-active surveillance and ablation

The incidence of renal cell carcinoma has been rising for years. At the same time there is an increasing prevalence of chronic renal failure with subsequent higher morbidity and shorter life expectancy in those affected. In the last decades the gold standard has thus shiftedfrom radical to partial nephrectomy or tumor enucleation. Atreatment alternative can be advantageous for selected patients with high morbidity and an increased risk of complications in anesthesia or surgery. Active surveillance represents acontrolled delay in the initiation of treatment with a curative intention. Percutaneous radiofrequency ablation and laparoscopic cryoablation are currently the most commonly used treatment alternatives. Newer ablation procedures, such as high-intensity focused ultrasound, irreversible electroporation, microwave ablation, stereotactic ablative radiotherapy and high-dose brachytherapy have a high potential in some cases but are still considered experimental for the treatment.

Laparoscopic vs Percutaneous Cryotherapy for Renal Tumors: A Systematic Review and Meta-Analysis.

Cryoablation has emerged as an alternative to the more invasive partial nephrectomy for small renal masses. The approach can be carried out by two techniques, either laparoscopic cryoablation (LCA) or percutaneous cryoablation, (PCA) with CT guidance. We aimed to compare between the two procedures. A systematic review and meta-analysis was conducted, including studies comparing the two techniques. Outcomes included incomplete ablation, late local recurrence, cancer-specific survival, procedure time, transfusion rates, hospital stay, and complications. A total of 1475 patients were included, 788 patients in the laparoscopic group and 687 patients in the percutaneous group. There was statistical difference favoring the laparoscopic group with regard to having less incomplete ablation (p = 0.0008) and higher cancer-specific survival patients (p = 0.04). However, there was longer hospital stays in the LCA group (p < 0.00001) and was found to be more costly than the PCA group. There was significantly more Clavien-I complications in the PCA group (p = 0.001) and more Clavien-III complications in the LCA group (p = 0.001). Otherwise, there were no differences in any other outcome parameter. LCA was found to have less incomplete tumor ablation rates and higher cancer-specific survival rates, however, higher hospitalization time, more major complications (Clavien III), and was costlier compared with PCA.

MP100-16 LAPAROSCOPIC RENAL CRYOABLATION USING REAL-TIME INTRAOPERATIVE THERMAL MONITORING: 15 YEAR EXPERIENCE

You have accessJournal of UrologyKidney Cancer: Ablative Therapy1 Apr 2017MP100-16 LAPAROSCOPIC RENAL CRYOABLATION USING REAL-TIME INTRAOPERATIVE THERMAL MONITORING: 15 YEAR EXPERIENCE Dean Laganosky, Mark Henry, Frances Kim, Peter Nieh, Viraj Master, and John Pattaras Dean LaganoskyDean Laganosky More articles by this author , Mark HenryMark Henry More articles by this author , Frances KimFrances Kim More articles by this author , Peter NiehPeter Nieh More articles by this author , Viraj MasterViraj Master More articles by this author , and John PattarasJohn Pattaras More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.3123AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Review of 15 year, single surgeon experience using laparoscopic cryoablation (LCA) and real-time intraoperative thermal monitoring for the management of small renal masses. We present treatment success and perioperative outcomes. METHODS We retrospectively analyzed 143 renal masses (128 patients) treated with LCA from 2001-2011, allowing for 5 year follow-up. Patients underwent retroperitoneal (RP) or transperitoneal (TP) LCA with objective thermal monitoring. After cryoneedle insertion, ≥2 thermal probes were placed within the tumor and outside the tumor margin to quantitatively assess temperatures. All tumors had ≥2 freeze cycles with a goal of achieving ≤-25°C at the periphery. Core tumor biopsies (3-6) were taken under direct vision during the first freeze cycle. Follow-up was recommended at least annually. Patient characteristics, operative details, pathology and perioperative labwork were analyzed. All cases of post-ablative radiologic persistence (lesion at ablation site) and recurrence (lesion outside of ablation site) were confirmed with biopsy or pathology from additional surgery. RESULTS Of 128 LCA patients (75 female, 53 male), mean age was 63 (30-83) years and BMI was 31.3kg/m2. Median ASA score was 3. Comorbidities included: hypertension (82/128), renal insufficiency (33/128), diabetes (28/128), ischemic cardiac disease (17/128) and solitary kidney (11/128). RP approach was used in 30/78 right vs 38/65 left-sided tumors with TP in the remainder. Mean tumor size was 3.0 (+/- 1.1) cm and surgical time was 211.1 (+/- 63.4) min. Two freeze cycles were performed in 97/143 tumors and mean freeze cycle duration was 11.0 (+/- 8.3) min. Mean EBL was 164.6mL and postop discharge was ≤24 hrs and ≤48 hrs in 45/133 and 84/133 of cases, respectively. Average hematocrit and eGFR change from pre- to postop was -5.1 mg/dL and 3.96 mL/min/1.73m2, respectively. Intraoperative biopsy (n=143) showed malignancy in 97 (67.8%) or oncocytic neoplasm in 21 (14.7%) cases. Of the remainder, 18 were benign (12.6%) and 6 were angiomyolipoma (4.2%). One sample was lost. Surgical limitations to tumor treatment were noted in only 3/143 (2.1%) tumors using our LCA technique. Of patients with biopsy-proven renal cancer or oncocytic neoplasm, 113/118 (95.8%) had no tumor persistence (mean radiologic follow-up 49.4 (+/-28.4) months (0.4-131.8 months)). Only 7/128 (5.5%) patients had recurrence. CONCLUSIONS Using objective thermal monitoring may improve intraoperative tumor control and decrease the likelihood of oncologic persistence when compared to traditional LCA. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1336-e1337 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Dean Laganosky More articles by this author Mark Henry More articles by this author Frances Kim More articles by this author Peter Nieh More articles by this author Viraj Master More articles by this author John Pattaras More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Laparoscopic cryoablation for renal cell carcinoma: 100-Month oncologic outcomes. Caputo PA, Ramirez D, Zargar H, Akca O, Andrade HS, O’Malley C, Remer EM, Kaouk JH. J Urol. 2015 Oct;194(4):892-896. [Epub 2015 April 23]. doi: 10.1016/j.juro.2015.03.128.

PurposeWith the incidence of renal cell carcinoma on the rise treatment options for the small renal mass have broadened. Cryoablation is increasingly used as a therapeutic option for renal tumors in select cases. However, studies with long-term oncologic outcomes are sparse. We evaluated the long-term oncologic outcomes of laparoscopic renal mass cryoablation. Materials and methodsWe reviewed our laparoscopic cryoablation database for patients treated with laparoscopic cryoablation from October 1997 to February 2005. Patients with less than 3 months of followup were excluded from study. Patient and tumor characteristics, and perioperative outcomes, including complications, were recorded. Recurrence-free, cancer specific and overall survival was analyzed using Kaplan-Meier curves. ResultsA total of 142 tumors in 138 consecutive patients were treated with laparoscopic cryoablation. Mean age of the cohort was 66.35 years. Of the patients 99 (71.7%) were male and 39 (28.3%) were female. Mean body mass index was 29.15kg/m(2) and median ASA score was 3. A solitary kidney was present in 23 patients (16.2%). Mean tumor size on cross-sectional imaging was 2.4cm. The mean preoperative and postoperative estimated glomerular filtration rate was 66.72 and 61.00ml per minute, respectively. The postoperative estimated glomerular filtration rate was determined at a mean±SD of 15.17±10.99 months of followup. The median R.E.N.A.L. nephrometry score was 5. Of the 142 tumors 100 were diagnosed as renal cell carcinoma after histopathological examination of the biopsy specimen. At 3, 5, and 10 years in patients diagnosed with renal cell carcinoma estimated recurrence-free survival was 91.4%, 86.5%, and 86.5%, estimated cancer specific survival was 96.8%, 96.8%, and 92.6%, and estimated overall survival was 88.7%, 79.1%, and 53.8%, respectively. Mean followup was 98.8±54.2 months in those diagnosed with renal cell carcinoma. Mean time to recurrence was 2.3 years. The latest experienced recurrence was 4.4 years after laparoscopic cryoablation. There was a postoperative complication rate of 10.6% with a total of 15 complications. ConclusionsLaparoscopic cryoablation achieves good long-term oncologic outcomes for localized small renal masses. It can safely be used in patients who cannot undergo or are unwilling to accept the risks of partial nephrectomy. Mean time to recurrence was 2.3 years and all recurrences developed within 4.4 years of initial treatment.

Laparoscopic cryoablation vs. percutaneous cryoablation for treatment of small renal masses: a systematic review and meta-analysis.

CONTEXTLaparoscopic cryoablation (LCA) and percutaneous cryoablation(PCA) have been used on patients with small renal masses(SRMs) for many years. However, clinical studies assessing their feasibility and safety have reported contradictory outcomes. This systematic evaluation was performed to obtain comprehensive evidence with regard to the feasibility and safety of PCA compared with LCA.METHODSA systematic search of Embase, Pubmed, Medline, the Cochrane Library were performed to identify studies that compared LCA with PCA were published up to Mar 2016. Outcomes of interest included perioperative, pathologic variables, and complications.RESULTSThirteen studies estimating LCA versus PCA were included for meta-analysis. Patients undergoing PCA were significantly older(WMD = -0.16 years; P = 0.01) and patients with posterior tumors were significantly prefer undergoing PCA than LCA(OR = 0.23; P = 0.0007), whereas patients with anterior tumors were significantly prefer undergoing LCA(OR = 3.82; P = 0.02). although PCA was associated with shorter hospital stay(WMD = 1.17 days; P < 0.0001) and higher incidence rate of perirenal hematoma(OR = 0.18; P < 0.0001). All the other analyzed parameters were similar, regardless of the surgical approach.CONCLUSIONSPatients undergoing PCA have shorter hospital stay and PCA was more frequently used in older patients and posterior tumors. Whereas LCA was associated with lower incidence rate of perirenal hematoma. Further multicenter, prospective and long-term follow-up RCTs are required to verify these findings.

Arterial Clamping Increases Central Renal Cryoablation Efficacy: An Animal Study.

The minimally invasive treatment of small renal masses with cryoablation has become increasingly widespread during the past 15 years. Studies with long-term follow-up are beginning to emerge, showing good oncological control, however, tumors with a central and endophytic location seem to possess an increased risk of treatment failure. Such tumors are likely to be subjected to a high volume of blood giving thermal protection to the cancerous cells. Arterial clamping during freezing might reduce this effect but at the same time subject the kidney to ischemia. The aim of this study was to evaluate the effect of renal artery clamping during cryoablation in a porcine survival model. Ten Danish Landrace pigs (approximately 40 kg) underwent bilateral laparoscopic cryoablation with clamping of the right renal artery during freezing. The cryoablation consisted of a standard double-freeze cycle of 10-minute freeze followed by 8 minutes of thaw. Arterial clamping subjected the right kidney to 2 cycles of ischemia (10 minutes) with perfusion in between. After surgery, the animals were housed for 14 days prior to computed tomography perfusions scans, radioisotope renography, and bilateral nephrectomy. No perioperative or postoperative complications were experienced. Mean differential renal function was 44% (95% confidence interval: 42-46) in the clamped right kidney group and 56% (95% confidence interval: 54-58) in the nonclamped left kidney group, P < .05. The ±5% technical inaccuracy is not accounted for in the results. Mean maximum temperature between freeze cycles was 5.13°C (95% confidence interval: -0.1 to 10.3) in the clamped right kidney group and 22.7°C (95% confidence interval: -16.6 to 28.8) in the nonclamped left kidney group, P < .05. Mean cryolesion volume, estimated on computed tomography perfusion, was 12.4 mL (95% confidence interval: 10.35-14.4) in the clamped right kidney group and 6.85 mL (95% confidence interval: 5.57-8.14) in the nonclamped left kidney group, P < .05. Pathological examination shows a higher degree of vital cells in the intermediate zone of the cryolesions in the nonclamped left kidneys when compared with the clamped right kidneys. Arterial clamping increases cryolesion size by approximately 80%, and pathologic examinations suggest a decreased risk of vital cells in the intermediate zone. The clamped kidneys showed no sign of injury from the limited ischemic insult. This study was limited by being a nontumor model.

Laparoscopic cryoablation of angiomyolipomas in adolescents and young adults: A report of four cases associated with tuberous sclerosis and 1 case of sporadic origin

Renal angiomyolipomas (AMLs) can be of sporadic origin or associated with tuberous sclerosis (TS). TS-associated AMLs often present in childhood, tend to be bilateral and multiple, and often exhibit a faster growth rate with an increased risk of hemorrhage. Renal cryoablation is well described in adults, whereas experiences with adolescents and young adults are limited. We present here for the first time a series of renal AMLs within adolescents and young adults treated with laparoscopic assisted cryoablation (LCA). The aim was to evaluate whether LCA of AMLs in adolescents and young adults is a safe and feasible treatment modality. From October 2009 to September 2013 a total of five patients at our institution were diagnosed with AMLs requiring treatment. Four patients had TS and one had AML of sporadic origin, all five patients underwent LCA. Data were retrospectively collected by a systematic review of patient material and reassessment of renal imaging. The median age was 16 years (range 13-27 years). Eight AMLs with a median size of 3.9cm (range 2.1-7.7cm) were treated in five patients because of tumor size and rapid growth. Follow-up was a median 37 months (range 20-62 months), and all tumors showed a reduction in tumor size, and no regrowth was recognized (see summary table). The procedure was well tolerated, with only few perioperative complications and no postoperative complications. When considering the indication for treating AMLs, the origin (sporadic or TS associated) and size of the tumor are the decisive factors. To preserve renal function and prevent spontaneous hemorrhage caution should be intensified when tumors reach 4cm, particularly if TS is present. After the diagnosis is established, patients should be monitored with renal imaging at regular intervals to identify rapid-growing tumors. As an alternative to current treatment modalities such as partial nephrectomy and super selective angioembolization, cryoablation is an emerging approach, although experience with pediatric patients is limited. For patients not requiring immediate surgery, pharmacological treatment with mTOR inhibitors is now being evaluated as an alternative treatment option or as neo-adjuvant therapy to ablative techniques. Prophylactic treatment of large or rapid growing AMLs with LCA appears to be a safe and feasible nephron-sparing approach in adolescents and young adults. The low perioperative complication rate and promising effect on outcome might allow treatment of subclinical AMLs in order to minimize the risk of potentially life-threatening complications and preserve renal function.

1094 Outcomes after laparoscopic assisted renal cryoablation: A retrospective EuRECA multinational analysis

1094 Outcomes after laparoscopic assisted renal cryoablation: A retrospective EuRECA multinational analysis

Preoperative Aspects and Dimensions Used for Anatomical Score Predicts Treatment Failures in Laparoscopic Cryoablation of Small Renal Masses.

To determine the potential of the preoperative aspects and dimensions used for anatomical (PADUA) classification score as a predictive tool in relation to residual unablated tumor and disease-free survival (DFS) following laparoscopy-assisted cryoablation (LCA) of small renal masses. A multi-institutional cohort of 212 patients with biopsy-verified T1N0M0 renal malignancies treated with LCA between August 2005 and September 2014 were retrospectively investigated with respect to oncologic outcomes. The preoperative PADUA score was found to be low (6-7 points) in 70 patients (33%), moderate (8-9 points) in 86 patients (40.6%), and high (10-14 points) in 56 patients (26.4%). The mean PADUA score was significantly higher in cases (n = 11) with residual unablated tumor (10.4 vs 8.1, p < 0.001) and in cases (n = 8) with local tumor recurrence (9.8 vs 8.1, p < 0.001) at a mean follow-up of 37 (95% confidence interval: 34-40) months. The estimated 2-, 3-, and 5-year DFS for patients with a moderate PADUA score was 96%, 94%, and 94% compared with 95%, 87%, and 81%, respectively, for patients with a high PADUA score (log-rank, p = 0.003). The PADUA score did not predict overall survival. The PADUA score significantly predicts residual unablated tumor and DFS following LCA. Further studies are needed to validate the efficacy of the PADUA score in relation to oncologic outcomes following ablative procedures.