Cryoablation Procedures Research Articles

Renal oncocytoma in a female patient with rheumatoid arthritis and secondary Sjögren’s syndrome: Non-coincidental link to autoimmunity?*

The objective of the article was to describe a female patient with rheumatoid arthritis (RA) and secondary Sjogren’s syndrome (SS) who developed a renal oncocytoma and was cured by percutaneous cryoablation therapy. A 72-year-old female patient with a long-term history of polyarthritis involving her hands, shoulders, knees, and ankles associated with morning stiffness and rheumatoid factor of 107 U/mL (nr: <29 U/mL) and anti-CCP of 121 U/mL (nr:<5 U/mL). A diagnosis of RA was determined 10 years ago, and prednisone with methotrexate were initiated, later changed for leflunomide 20mg/day. In 2014 a diagnosis of secondary SS was determined. In April 2014, during a routine abdominal ultrasound, a tumor was found in her left kidney. A magnetic resonance imaging confirmed a solid nodule with hypervascularization on the left kidney. She was submitted to a percutaneous cryoablation procedure without any intercurrence, and it had success. The histopathological analysis demonstrated a renal oncocytoma limited to the left kidney. No chemotherapy or radiotherapy was needed. After surgery, a flare of RA was noted and was resistant to methotrexate and sulfasalazine. Rituximab was then started, and she had an excellent progressive response. Minor thyroid changes were registered by ultrasound monitoring and signs of hyperparathyroidism manifested. This observation illustrates the first ever described case of a patient with RA and secondary SS who developed several years after the RA onset, a renal oncocytoma, and was successfully treated with cryoablation therapy. The possible links between oncocytic cell metaplasia/neoplasia and autoimmunity are discussed.

A Single-Center 10-Year Retrospective Analysis of Cryoablation for the Management of Desmoid Tumors

PurposeTo determine the efficacy and safety of cryoablation in patients with desmoid tumors (DTs) retrospectively over a 10-year period at a single institution. Materials and MethodsBetween February 25, 2010, and February 25, 2020, 25 patients (age, 12–80 years) with 26 lesions (mean preprocedural tumor volume was 237 cm3) were treated over 44 cryoablation procedures. Eleven patients were treated with first-line therapy. Fourteen patients had previous medical therapy, radiotherapy, and/or surgery. Subsequent clinical follow-up, imaging outcomes, and safety were analyzed for technical success, change in total lesion volume (TLV) and viable tumor volume (VTV), modified response evaluation criteria in solid tumors (mRECIST), progression-free survival (PFS) for tumor progression and symptom recurrence, symptom improvement, and procedure-related complications. Symptomatic improvement was defined as documentation of relief of pain (partial or complete) and/or functional impairment. ResultsAll procedures were technically successful. At 7–12 months, median changes in TLV and VTV were −6.7% (P = .809) and −43.7% (P = .01), respectively. At 10–12 months, the mRECIST responses were complete response, 0%; partial response, 61.5% (8/13); stable disease, 30.8% (4/13); and progressive disease, 7.7% (1/13). The median PFS for tumor progression and symptom recurrence were not reached, with a median follow-up of 15.3 and 21.0 months, respectively. Symptomatic relief (partial or complete) was achieved in 96.9% (32/33) of patients. One major complication was noted (2.4%). ConclusionsIn this retrospectively identified cohort, cryoablation was effective and safe for the local control of extra-abdominal DTs in short-term follow-up.

Virtual Reality for Sedation During Atrial Fibrillation Ablation in Clinical Practice: Observational Study.

BackgroundConnected devices are dramatically changing many aspects in health care. One such device, the virtual reality (VR) headset, has recently been shown to improve analgesia in a small sample of patients undergoing transcatheter aortic valve implantation.ObjectiveWe aimed to investigate the feasibility and effectiveness of VR in patients undergoing atrial fibrillation (AF) ablation under conscious sedation.MethodsAll patients who underwent an AF ablation with VR from March to May 2020 were included. Patients were compared to a consecutive cohort of patients who underwent AF ablation in the 3 months prior to the study. Primary efficacy was assessed by using a visual analog scale, summarizing the overall pain experienced during the ablation.ResultsThe AF cryoablation procedure with VR was performed for 48 patients (mean age 63.0, SD 10.9 years; n=16, 33.3% females). No patient refused to use the device, although 14.6% (n=7) terminated the VR session prematurely. Preparation of the VR headset took on average 78 (SD 13) seconds. Compared to the control group, the mean perceived pain, assessed with the visual analog scale, was lower in the VR group (3.5 [SD 1.5] vs 4.3 [SD 1.6]; P=.004), and comfort was higher in the VR group (7.5 [SD 1.6] vs 6.8 [SD 1.7]; P=.03). On the other hand, morphine consumption was not different between the groups. Lastly, complications, as well as procedure and fluoroscopy duration, were not different between the two groups.ConclusionsWe found that VR was associated with a reduction in the perception of pain in patients undergoing AF ablation under conscious sedation. Our findings demonstrate that VR can be easily incorporated into the standard ablation workflow.

Early discharge after cryoablation procedure: is it safe?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Discharge after overnight hospital stay is standard procedure in patients submitted to elective atrial fibrillation (AF) ablation. Taking into consideration the low rate of cryoablation procedure complications could the same day discharge be an option? Purpose To access the safety of same day discharge of patients submitted to AF cryoablation. Methods Single-center retrospective study of consecutive pts admitted to elective AF cryoablation in a tertiary center between February 2017 and November 2020. Patients were divided into two groups: same day discharge and next day discharge. Only patients submitted to ablation until 4 p.m. were included. Complication rates were obtained up to six months after the procedure. Complications were defined as death, pericardial tamponade, hematoma requiring evaluation and/or intervention, major bleeding requiring transfusion, hospital admission related to the procedure. Results One hundred fifty-four pts were included, with a mean age of 61 ± 10.9 years, 66.2% were males, 18.2% with diabetes, 65.6% with dyslipidemia, 77.9% with hypertension, 10.4% with chronic kidney disease KDIGO stage 3 or more. Median follow-up of 436 (IQ 178 – 729) days. Most of the pts had paroxysmal (73.4%) and persistent short duration AF (23.4%). Sixty-two pts (40.3%) were early discharged and there were no differences between the two groups regarding epidemiological and clinical characteristics (p = NS). A very low rate of complications in both groups was observed, occurring in 6.5% of pts with early discharge and in 8.7% of pts in overnight stay, without statistical significance between the two groups (p = 0.61). The most frequent complications were local hematoma (5 pts, 2 in early discharged group), pericardial effusion (3 pts, all in overnight stay), femoral pseudo-aneurism (2 pts, 1 in each group) and arteriovenous fistula (1 pt in overnight stay group). The type of complications did not differ between the two groups (p = 0.51). Two pts died during the follow up, unrelated with the procedure. In addition, no difference in success rate and arrhythmic recurrence was observed between the two groups. (p = NS) Conclusion Our study suggests that is safe to early discharge pts submitted to AF ablation, reducing the hospital stay length in selected pts. Larger studies are needed to confirm this data before routine implementation of this strategy.

Percutaneous Argon-Helium Cryoablation for Small Hepatocellular Carcinoma Located Adjacent to a Major Organ or Viscus: A Retrospective Study of 92 Patients at a Single Center.

BackgroundCryoablation of hepatocellular carcinoma (HCC) close to major organs or viscus is challenging because it can cause complications. This retrospective study aimed to investigate the safety and efficacy of percutaneous argon-helium cryoablation of small HCC located adjacent to major organs or viscus.Material/MethodsNinety-two patients who underwent percutaneous argon-helium cryoablation between February 2012 and December 2018 at the Fifth Medical Center of the Chinese People’s Liberation Army General Hospital were included. Treatment efficacy was evaluated by magnetic resonance imaging or triphasic computed tomography scan within 1 week after each cryoablation procedure. Local tumor progression, distant recurrence, and overall survival were analyzed using the Kaplan-Meier method and log-rank test.ResultsA total of 92 patients with small HCC located adjacent to major organs or viscus who underwent cryoablation were retrospectively reviewed. The number of patients with tumors adjacent to the gallbladder, portal or hepatic vein, diaphragm, stomach, heart, and intestine was 22, 1, 39, 6, 8, and 16, respectively. Cumulative local tumor progression rates at 1 and 2 years were 2.8% and 7.3%, respectively. Cumulative distant recurrence rates at 1, 2, and 3 years were 11.1%, 17.6%, and 20.7%, respectively. The overall survival rates at 1, 2, and 4 years were 100%, 93.6%, and 74.9%, respectively. Major complications were observed in 5 (5.4%) patients. Minor complications were observed in 85 (92.4%) patients.ConclusionsThis experience from a single center showed that percutaneous argon-helium cryoablation was safe and effective in the management of small HCC that is located adjacent to major organs or viscus.

Radiation dose reduction in CT-guided cryoablation of renal tumors.

We aimed to evaluate the effect on the radiation dose to the patient by reducing the tube current during the placement of the ablation needles (reduced dose group) compared with the patient doses delivered when scanning at the standard fully diagnostic level (full dose group) in computed tomography (CT)-guided percutaneous cryoablation. We conducted a retrospective study of 103 patients undergoing cryoablation in a tertiary cancer center. Overall, 62 patients were scanned with standard exposure parameters (full dose group) set on a 64-slice multidetector CT scanner, while 41 patients were scanned on a reduced dose protocol. Dose levels were retrieved from the hospital picture and archiving communication system including the volumetric CT dose index (CTDIvol), total dose length product (DLP), length of cryoablation procedure, number of cryoablation needles and patient size. Wilcoxon Mann-Whitney (rank-sum) tests were used to compare the median DLP, CTDIvol and skin dose between the two groups. Median total DLP for the full dose group was 6025 mGy•cm (1909-13353 mGy•cm) compared with 3391 mGy•cm (1683-6820 mGy•cm) for the reduced dose group. The reduced dose group had a 44% reduction in total DLP and 42% reduction in total CTDIvol (p < 0.001). The estimated skin doses were 384 mGy for the full dose group and 224 mGy for the reduced dose group (42% reduction) (p < 0.001). At 12-month follow-up, the technical success for the full dose (n=62) was 97% with 2 patients requiring a further cryoablation treatment for residual tumor. The technical success for the reduced dose group (n=41) was 100%. CT dose reduction technique during image-guided cryoablation treatment of renal tumors can achieve significant radiation dose reduction whilst maintaining sufficient image quality.

Assessing ablation margins of FDG-avid liver tumors during PET/CT-guided thermal ablation procedures: a retrospective study

To retrospectively assess liver tumor ablation margins using intraprocedural PET/CT images from FDG PET/CT-guided microwave or cryoablation procedures and to correlate minimum margin measurements with local progression outcomes. Fifty-six patients (ages 36 to 85, median 62; 32 females) with 77 FDG-avid liver tumors underwent 60 FDG PET/CT guided, percutaneous microwave, or cryoablation procedures. Single breath-hold PET/CT images were used for intraprocedural assessment of the tumor ablation margin: liver tumors remained visible on PET immediately following ablation; microwave ablation zones were visible using contrast-enhanced CT; cryoablation zones (ice balls) were visible using unenhanced CT. Two readers retrospectively determined ablation margin assessability and measured the minimum ablation margin on intraprocedural PET/CT (n = 77) and postprocedural MRI (n = 56). Local tumor progression was assessed on all available follow-up imaging (1-49 months, mean 15). Local tumor progression was correlated with PET/CT minimum margin measurements using clustered survival models for 61 tumors. Minimum ablation margins were more often assessable using intraprocedural PET/CT (≥ 73/77 tumors, 95%) than postprocedural MRI (≤ 35/56 tumors, 63%). In 61 tumors with PET/CT-assessable margins (excluding tumors with overlapping ablations after PET/CT), there was a 6-fold increased risk of local tumor progression [hazard ratio (HR) 6.05; P = 0.004] for minimum ablation margins < 5 mm. Breath-hold PET/CT scans, during PET/CT-guided microwave or cryoablation procedures for FDG-avid liver tumors, enable reliable intraprocedural assessment of the entire tumor ablation margin; a minimum PET/CT ablation margin threshold of 5 mm correlates well with local tumor progression outcomes.

Percutaneous cryoablation of adrenal metastases: technical feasibility and safety.

To assess the technical feasibility and outcomes of adrenal metastases cryoablation. This is an IRB approved retrospective review of adrenal metastases cryoablation between April 2003 and October 2018. Forty percutaneous cryoablation procedures were performed on 40 adrenal metastases in 34 patients. Histology, tumor size, ablation zone size, major vessel proximity, local recurrences, complications, and anesthesia-managed hypertension monitoring was collected. Complications were graded according to the Common Terminology of Complications and Adverse Events (CTCAE). Mean tumor and ablation size was 3.2cm and 5.2cm, respectively. Local recurrence rate was 10.0% (N = 4/40) for a mean follow-up time of 1.8years. Recurrences for tumors > 3cm (21.0%, N = 4/19) was greater than for tumors ≤ 3cm (0.0%, N = 0/21) (p = 0.027). Proximity of major vasculature (i.e., IVC & aorta) did not statistically effect recurrence rates (p = 0.52), however, those that recurred near vasculature were > 4cm. Major complication (≥ grade 3) rate was 5.0% (N = 2/40), with one major complication attributable to the procedure. Immediate escalation of blood pressure during the passive stick phase (between freeze cycles) or post procedure thaw phase was greater in patients with residual adrenal tissue (N = 21/38) versus masses replacing the entire adrenal gland (N = 17/38), (p = 0.0020). Lower blood pressure elevation was noted in patients with residual adrenal tissue who were pre-treated with alpha blockade (p = 0.015). CT-guided percutaneous cryoablation is a safe, effective and low morbidity alternative for patients with adrenal metastases. Transient hypertension is related only to residual viable adrenal tissue but can be safely managed and prophylactically treated.

Fluoroless catheter ablation of accessory pathways in adult and pediatric patients: a single centre experience.

Catheter radio-frequency ablation (RFA) and cryo-ablation (CRA) procedures are an effective and safe treatment options for adult and pediatric patients with accessory pathway (AP) mediated tachycardias. Non-fluoroscopic techniques during catheter ablation (CA) procedures reduce potentially harmful effects of radiation. Our aim was to investigate the efficacy and safety of completely fluoroless RFA and CRA procedures in pediatric and adult patients with APs. Consecutive patients with AP-related tachycardia and high risk asymptomatic ventricular pre-excitation were assessed in retrospective analysis. Three-dimensional (3D) electro-anatomical mapping (EAM) and intra-cardiac echocardiography (ICE) were used as principal imaging modalities. Fluoroscopy was not used during any stage of the procedures. Among 116 included patients (22.76 ± 16.1years, 68 patients < 19years), 60 had left-sided APs, 16 right-sided APs and 40 septal APs. Altogether, 96 had RFA and 20 CRA procedures. The acute success rates (ASR) of RFA and CRA were 97.9% and 95%, respectively (p = 0.43), with recurrence rates (RR) of 8.33% and 40%, respectively (p < 0.0001). The outcome difference was principally driven by lower RR with RFA in septal APs (9.1% vs. 38.9%, p = 0.025). Pediatric patients with APs (12.21 ± 3.76years) had similar procedural parameters and outcomes compared to adult patients. There were no procedure-related complications. In adult and pediatric patients with AP-related tachycardias, both CRA and RFA can be effectively and safely performed without the use of fluoroscopy. In addition, RFA resulted in better outcomes compared to CRA.

Percutaneous thoracic cryoablation of primary lung and pleural tumors: Analysis of long-term experience of feasibility, safety, and recurrence parameters

Objectives: The objectives of the study were to report long-term experience with percutaneous thoracic cryoablation, including both malignant pleural and primary pulmonary tumors, assessing factors affecting complications and local recurrence rates. Material and Methods: After Institutional Review Board approval and Health Insurance Accountability Act compliance, a retrospective review of 50 patients who underwent 85 CT fluoroscopic-guided percutaneous cryoablation procedures for 116 masses, consisting of non-small cell lung cancer (n = 61), small cell lung cancer (n = 1), mesothelioma (n = 16) and malignant profile fibrous tumors (n = 38) was performed. Tumor size and location (central vs. peripheral) were noted in relation to major vasculature. Hydrodissection and/or esophageal warming balloons were utilized for the protection of crucial structures. Complications were graded according to standardized Common Terminology Criteria for Adverse Events criteria. Patients were followed by CT and/or MRI at 1, 3, 6, 12, 18, and 24 months and yearly, thereafter. Results: Mean tumor diameter was 3.3 cm and 3.0 cm for primary lung tumors (PLTs) and malignant pleural tumors (MPTs), respectively. The mean number of cryoprobes utilized was 3.7 per tumor, which produced ablation zones with CT visible ice mean diameters of 5.3 cm. Hydrodissection and/or warming balloon protections were used in 15.3% (n = 13/85). Grade ≥3 complications were limited to tumors &gt;3 cm (8.2% = 7/85; P = 0.0042), but did not appear significant for central location. At a mean follow-up of 17.0 months, overall local tumor recurrence was 6.9% (n = 8/116). Pleural tumors had lower recurrence rates than PLTs (1.8% [n = 1/54] vs. 11.3% [n = 7/62], respectively; P &lt; 0.21). Tumors &gt;3 cm or central location had statistically significant higher recurrence rates, (P = 0.021) and (P = 0.039), respectively. Central recurrences occurred predominantly in tumors &gt;3 cm (20%, n = 5/25). Conclusion: With appropriate pre-treatment, evaluation, and procedural criteria, percutaneous cryoablation of both primary lung and pleural tumors is safe and produces very low local recurrence rates, especially for tumors ≤3 cm.

Intraprocedural MRI monitoring during percutaneous cryoablation procedures of the head and neck, and spine: a single institution experience

Rationale and objectivesEvaluate whether intraprocedural MRI monitoring of percutaneous cryoablation procedures of head and neck, and spine lesions is effective for avoiding iatrogenic neurovascular and mucosal injury. Materials and methodsWe retrospectively reviewed 64 consecutive percutaneous head and neck, and spine cryoablation procedures with intraprocedural MRI monitoring performed on 45 patients (mean age 55 years, range 17–91 years). Ablation goals were either complete local control of primary or metastatic lesions or pain relief. ResultsThe technical success rate was 100%. The complication rate was 13% with only 2 complications (3%) requiring further intervention. There were no deaths or persistent neurological or vascular complications. Subsequent cryoablation in the same location was performed in 12 patients (27%). Subsequent surgical intervention in the same location was performed in 7 patients (16%) for progressive disease or worsening symptoms. ConclusionsMRI provides excellent visualization of the ice ball margin during percutaneous cryoablation procedures. Accurate intraprocedural visualization of the ice ball allows for adjustment of cryoablation parameters to avoid damage to adjacent vital neurovascular structures or mucosal surfaces. Intraprocedural MRI monitoring is thus a novel and highly effective method that allows a high rate of technical success for cryoablation in the head and neck, and spine while avoiding iatrogenic injury.

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique: 4-year follow-up

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon). Methods One hundred and fifty patients (paroxysmal AF: 99 patients, persistent AF: 51 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (Arctic Front Balloon: 75 patients (group A); Arctic Front Advance: 75 patients (group B)). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (CARTO) depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.7 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.3 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 65 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1–3 reconnected PVs; group A1). In the remaining 10 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor reconnection of 1–2 PVs. All recovered PVs could be isolated sucessfully again. At 48-month follow-up, 74.7% of all patients were free from an arrhythmia recurrence (112/150 patients; group A: 51/75 patients (68%), group B: 61/75 patients (81.3%)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon). Funding Acknowledgement Type of funding source: None

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.

Intermediate to Long-Term Clinical Outcomes of Percutaneous Cryoablation for Renal Masses

PurposeThe purpose of this study was to evaluate the effectiveness and adverse outcomes of percutaneous cryoablation (CA) for treatment of renal masses in a large cohort of patients. Materials and MethodsThis retrospective analysis included 299 CA procedures (297 masses in 277 patients) performed between July 2007 and May 2018 at a single institution. The mean patient age was 66.1 years (range, 30–93 years) with 65.8% being male. A total of 234 (78.8%) masses were biopsy-proven renal cell carcinoma (RCC). The mean maximal tumor diameter was 2.5 cm (range, 0.7–6.6 cm). Efficacy was assessed only for ablations of biopsy-proven RCC, whereas the evaluation of adverse events and renal function included all masses. Complications were graded according to the Society of International Radiology classification. ResultsMajor complications occurred in 3.0% of procedures (n = 9), none of which resulted in death or permanent disability. The mean imaging follow-up period was 27.4 months (range, 1–115) for the 199 RCC patients (204 ablated tumors) with follow-up imaging available. Complete response on initial follow-up imaging at mean 4.2 months (range, 0.3–75.6) was achieved in 195 of 204 tumors (95.6%) after a single session and in 200 of 204 tumors (98.0%) after 1 or 2 sessions. Of the RCC patients achieving complete response initially, local recurrence during the follow-up period occurred in 3 of 200 tumors (1.5%). Metastatic progression occurred in 10 of 193 (5.2%) RCC patients without prior metastatic disease during follow-up. ConclusionsCA for renal masses is safe and remains efficacious through intermediate- and long-term follow-up.

P1382Extended long-term follow-up of radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (first versus second generation cryoballoon)

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon). Methods One hundred and twenty patients (paroxysmal AF: 78 patients, persistent AF: 42 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique. The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.8 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.5 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 53 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 7 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 42-month follow-up, 78 % of all patients were free from an arrhythmia recurrence (94/120 patients; group A: 43/60 patients (71 %), group B: 51/60 patients (85 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

P1061Incidence and location of PVI gaps identified post-cryoballoon ablation for atrial fibrillation

Abstract Background Successful delivery of continuous and durable pulmonary vein isolation (PVI) lesion sets is recognized as being critical to long-term clinical outcomes following ablation for atrial fibrillation (AF). Confirmation of PVI following cryoballoon ablation is commonly achieved using a 3.3F circular mapping catheter (CMC) which can be delivered through the central lumen of the cryoballoon, but other diagnostic tools may be used alone or in conjunction with the 3.3F CMC. A high-density, grid-style mapping catheter is now available in multiple geographies; use in cryoballoon ablation procedures and associated outcomes has not been previously reported. Purpose To evaluate diagnostic catheter usage patterns in cryoablation procedures and identify associated trends in procedural characteristics and acute outcomes. Methods Self-reported procedural data was prospectively collected in AF cryoablation cases utilizing various diagnostic catheter tools, including the 3.3F CMC and high-density, grid-style mapping catheter (HD Grid). Procedural characteristics and acute outcomes, including the incidence and location of gaps post-ablation, were recorded and analyzed. Results Data was collected in 23 cryoablation procedures performed in 7 centers across the United States and Europe. De novo and repeat ablations represented 65.2% and 21.7% of cases, respectively (13.0% not reported). 3D mapping was employed in 95.7% of cases. A left common pulmonary vein was present and ablated in 8.7% (2/23). The 28mm cryoballoon was utilized in all cases, with a single case using both a 23mm and 28mm cryoballoon. The 3.3F CMC was used to confirm isolation in all cases using a variety of techniques: voltage mapping (60.9%), exit block (56.5%), entrance block (30.4%), propagation mapping (4.3%), and activation mapping (4.3%); note: total exceeds 100% as more than one technique may be employed in a single case. In 18 cases, PVI was confirmed using a 3.3F CMC followed by secondary confirmation with HD Grid, enabling a direct comparison of the two technologies. The HD Grid identified a total of 12 gaps in 4 (22.2%) patients, which were missed by the 3.3F CMC (Figure 1). No adenosine or isoproterenol use was documented in any case. Conclusion(s): The 3.3F CMC is routinely used to confirm PVI following cryoballoon ablation for atrial fibrillation, but it may fail to identify gaps in some patients. Subsequent assessment of PVI using the HD Grid identified residual gaps in nearly a quarter of patients, suggesting that sensitivity for gap detection may be improved with this tool. Limitations of this analysis include the small sample size and workflows which consistently assessed PVI with the high-density mapping catheter after confirming isolation with the 3.3F CMC. Despite these limitations, the incidence of residual gaps observed is noteworthy and may warrant additional study. Abstract Figure.

Percutaneous cryoablation in pediatric solid tumors: A case series.

e22516 Background: Percutaneous cryoablation is an effective treatment of focal tumors. With a low complication rate it is a useful adjuvant therapy option to chemotherapy and radiation. To date there is no literature on the use of cryoablation in pediatric solid tumors. Methods: We conducted a retrospective analysis of pediatric solid tumor patients who received percutaneous cryoablation for local control of relapsed disease over the past 10 years within our institution. The following information was extracted from EMR: age, diagnosis, number of ablated lesions and tissue involved (lung, liver, bone), complications following procedure, and rate of local relapse. Results: A total of 40 metastatic lesions were treated by percutaneous cryoablation in 7 patients (ages 5-22yo, median 15yo) with a wide range of solid tumor diagnoses (Ewing sarcoma, Wilms tumor, Osteosarcoma, Germ cell tumor). Lesions represented sites of relapse or metastasis, refractory to several lines of therapy. Sites of cryoablated tumor included lung (33%), bone (32%), chest wall (10%) among others. Each patient had 2-5 separate cryoablation procedures (total 22 procedures) over the course of their therapy. 54% of instances patients were monitored overnight for pain control, with no major complications. One patient required ICU-level care due to pulmonary hemorrhage following lung cryoablation in setting of thrombocytopenia. No infectious complications. Three patients progressed and died within two years following first cryoablation intervention (diagnoses of Ewings and Wilms). Of the remaining four patients, control at the ablation site was achieved with median follow-up of 17 months (range 8-43). Conclusions: Percutaneous cryoablation is a safe and durable approach for local control of solid tumors in children. We present the first pediatric case series detailing response to percutaneous cryoablation.

Temperature-Sensitive Frozen-Tissue Imaging for Cryoablation Monitoring Using STIR-UTE MRI.

The aim of this study was to develop a method to delineate the lethally frozen-tissue region (temperature less than -40°C) arising from interventional cryoablation procedures using a short tau inversion-recovery ultrashort echo-time (STIR-UTE) magnetic resonance (MR) imaging sequence. This method could serve as an intraprocedural validation of the completion of tumor ablation, reducing the number of local recurrences after cryoablation procedures. The method relies on the short T1 and T2* relaxation times of frozen soft tissue. Pointwise Encoding Time with Radial Acquisition, a 3-dimensional UTE sequence with TE = 70 microseconds, was optimized with STIR to null tissues with a T1 of approximately 271 milliseconds, the threshold T1. Because the T1 relaxation time of frozen tissue in the temperature range of -40°C < temperature < -8°C is shorter than the threshold T1 at the 3-tesla magnetic field, tissues in this range should appear hyperintense. The sequence was evaluated in ex vivo frozen tissue, where image intensity and actual tissue temperatures, measured by thermocouples, were correlated. Thereafter, the sequence was evaluated clinically in 12 MR-guided prostate cancer cryoablations, where MR-compatible cryoprobes were used to destroy cancerous tissue and preserve surrounding normal tissue. The ex vivo experiment using a bovine muscle demonstrated that STIR-UTE images showed regions approximately between -40°C and -8°C as hyperintense, with tissues at lower and higher temperatures appearing dark, making it possible to identify the region likely to be above the lethal temperature inside the frozen tissue. In the clinical cases, the STIR-UTE images showed a dark volume centered on the cryoprobe shaft, Vinner, where the temperature is likely below -40°C, surrounded by a doughnut-shaped hyperintense volume, where the temperature is likely between -40°C and -8°C. The hyperintense region was itself surrounded by a dark volume, where the temperature is likely above -8°C, permitting calculation of Vouter. The STIR-UTE frozen-tissue volumes, Vinner and Vouter, appeared significantly smaller than signal voids on turbo spin echo images (P < 1.0 × 10), which are currently used to quantify the frozen-tissue volume ("the iceball"). The ratios of the Vinner and Vouter volumes to the iceball were 0.92 ± 0.08 and 0.29 ± 0.07, respectively. In a single postablation follow-up case, a strong correlation was seen between Vinner and the necrotic volume. Short tau inversion-recovery ultrashort echo-time MR imaging successfully delineated the area approximately between -40°C and -8°C isotherms in the frozen tissue, demonstrating its potential to monitor the lethal ablation volume during MR-guided cryoablation.

Adenosine usage during AF ablation in Europe and selected long-term findings from the ESC-EHRA EORP Atrial Fibrillation Ablation Long-Term registry

BackgroundAdenosine can be used to reveal dormant pulmonary vein (PV) conduction after PV isolation (PVI). This study presents a subanalysis of real-world 1-year follow-up data from the ESC-EHRA EORP Atrial Fibrillation (AF) Ablation Long-Term registry to analyze the usage of adenosine during PVI treatment in terms of rhythm outcome and safety.MethodsThe registry consists of 104 participating centers in 27 countries within the European Society of Cardiology. The registry data was split into an adenosine group (AG) and no-adenosine group (NAG). Procedure characteristics and patient outcome were compared.ResultsAdenosine was administered in 10.8% of the 3591 PVI patients included in the registry. Spain, the Netherlands, and Italy included the majority of adenosine cases (48.8%). Adenosine was applied more often in combination with open irrigation radiofrequency (RF) energy (74.7%) and less often in combination with nonirrigated RF energy (1.6%). After 1 year, a higher percentage of the AG was free from AF compared with the NAG (68.9% vs 59.1%, p < 0.001). Adenosine was associated with better rhythm outcome in RF ablation procedures, but not in cryo-ablation procedures (freedom from AF: RF: AG: 70.9%, NAG: 58.1%, p < 0.001, cryo: AG: 63.9%, NAG: 63.8%, p = 0.991).ConclusionsThe use of adenosine was associated with a better rhythm outcome after 1 year follow-up and seems more useful in patients treated with RF energy compared with patients treated with cryo energy. Given the improved rhythm outcome at 1-year follow-up, it seems reasonable to encourage the use of adenosine during RF AF ablation.

V14-05 MRI FUSION GUIDED PROSTATE PARTIAL GLAND CRYOABLATION AIDED BY A VIRTUAL 3D MODELING: A STEP BY STEP ILLUSTRATION

You have accessJournal of UrologyProstate Cancer (V14)1 Apr 2020V14-05 MRI FUSION GUIDED PROSTATE PARTIAL GLAND CRYOABLATION AIDED BY A VIRTUAL 3D MODELING: A STEP BY STEP ILLUSTRATION Ezequiel Becher*, Nicole Wake, Zachary Tano, Nermarie Velazquez, Herbert Lepor, and James Wysock Ezequiel Becher*Ezequiel Becher* More articles by this author , Nicole WakeNicole Wake More articles by this author , Zachary TanoZachary Tano More articles by this author , Nermarie VelazquezNermarie Velazquez More articles by this author , Herbert LeporHerbert Lepor More articles by this author , and James WysockJames Wysock More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000982.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To describe our technique for prostate partial gland cryoablation (PGCy) aided by a virtual 3D model and with magnetic resonance imaging (MRI)- ultrasound (US) fusion guidance. METHODS: Preoperatively, multiparametric prostate MRI imaging is used to develop a 3D virtual prostate model defining tumor location and planned treatment margin as well as critical structures such as the urethra, neurovascular bundle and rectum. This model also allows pre-treatment simulation using 3D virtual cryoprobes. Planning for number of treatment probes and probe configuration/location are simulated using this model to ensure confluent treatment volume. The cryoablation procedure is performed under general anesthesia with the patient in dorsal lithotomy position. A biplanar transrectal ultrasound probe is used to visualize the prostate. The Navigo® transperineal MRI-US fusion system creates 3D ultrasound segmentation and performs MRI registration prior to cryoprobe placement. A 1 cm tumor margin is employed. Combining the fusion image guidance and 3D virtual planning, cryoprobe and thermocouple placement planning is performed. After placement of a urethral warming catheter, two freeze-thaw cycles are performed. Treatment temperatures and US monitoring of ice development are performed in real-time. The procedure is completed after adequate treatment volume and a target freeze temperature has been achieved. An additional third freeze-thaw cycle may be performed on a case-by-case basis. RESULTS: This case illustrates PGCy using 3D pre-ablation modeling. The pretreatment model based upon mpMRI and assuming a 1 cm margin predicted use of 3 cryoprobes to achieve confluent treatment volume. The use of MRI-US fusion and execution of the 3D modeling is demonstrated. PGCy was safely done with 2 freeze / thaw cycles. CONCLUSIONS: Our virtual 3D model and MRI fusion guidance allowed us to plan for a more accurate and oncologically safe PGCy. This video also serves to show our technique to approaching PGCy. Source of Funding: Department of Urology, NYU Langone Health. © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e1307-e1307 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ezequiel Becher* More articles by this author Nicole Wake More articles by this author Zachary Tano More articles by this author Nermarie Velazquez More articles by this author Herbert Lepor More articles by this author James Wysock More articles by this author Expand All Advertisement PDF downloadLoading ...