Irrigated Catheter Research Articles

Endoscopy Upper

Endoscopy Upper

Temperature-Controlled Radiofrequency Ablation for Pulmonary Vein Isolation in Patients With Atrial Fibrillation

BackgroundSaline irrigation improved the safety of radiofrequency (RF) ablation, but the thermal feedback for energy titration is absent. ObjectivesTo allow temperature-controlled irrigated ablation, a novel irrigated RF catheter was designed with a diamond-embedded tip (for rapid cooling) and 6 surface thermocouples to reflect tissue temperature. High-resolution electrograms (EGMs) from the split-tip electrode allowed rapid lesion assessment. The authors evaluated the preclinical and clinical performance of this catheter for pulmonary vein (PV) isolation. MethodsUsing the DiamondTemp (DT) catheter, pigs (n = 6) underwent discrete atrial ablation in a temperature control mode (60°C/50 W) until there was ∼80% EGM amplitude reduction. In a single-center clinical feasibility study, 35 patients underwent PV isolation with the DT catheter (study group); patients were planned for PV remapping after 3 months, regardless of symptomatology. A control group included 35 patients who underwent PV isolation with a standard force-sensing catheter. ResultsPorcine lesion histology revealed transmurality in 51 of 55 lesions (92.7%). In patients, all PVs were successfully isolated; no char or thrombus formation was observed. Compared with the control group, the study cohort had shorter mean RF application duration (26.3 ± 5.2 min vs. 89.2 ± 27.2 min; p < 0.001), shorter mean fluoroscopic time (11.2 ± 8.5 min vs. 19.5 ± 6.8 min; p < 0.001), and lower acute dormant PV reconduction (0 of 35 vs. 5 of 35; p = 0.024). At 3 months, 23 patients underwent remapping: 39 of 46 PV pairs (84.8%) remained durably isolated in 17 of these patients (73.9%). ConclusionsThis first-in-human series demonstrated that temperature-controlled irrigated ablation produced rapid, efficient, and durable PV isolation. (ACT DiamondTemp Temperature-Controlled and Contact Sensing RF Ablation Clinical Trial for Atrial Fibrillation [TRAC-AF]; NCT02821351)

Efficacy and safety of RevoLix 2 micron continuous wave laser vaporesection in treatment for senile patients with benign prostatic hyperplasia

The clinical efficacy and safety of RevoLix 2 μm continuous wave laser vaporesection in treatment of senile patients with benign prostatic hyperplasia (BPH) were retrospective evaluated. In 291 senile patients with BPH, 213 received 2 μm continuous wave laser vaporesection (group A) and other 78 patients received transurethral resection of prostate (TURP, group B). Compared with group B the intraoperative blood loss was less, the bladder irrigation time, catheter time and hospitalization time were shorter in group A. The subjective or objective indexes were all significantly improved at 3 and 12 months after laser treatment. The improvements of international prostate symptom score (IPSS), IPSS-S, overactive bladder symptom score (OABSS) in patients of 70-79 were more marked than those of 80 or older. Patients with mild overactive bladder (OAB) had less improvement in IPSS and IPSS-S than those with moderate-severe OAB which suggest that the storage symptoms could be improved significantly by removing obstruction. Key words: Lasers therapy; Prostatic hyperplasia; Transurethral resection of prostate

Invention of the Guide Catheter Irrigation Monitoring Device for Neuroendovascular Therapy.

ObjectiveThe thromboembolic events during neuroendovascular therapy (NET) are the major complications of concern that can be occasionally fatal. The thrombotic occlusion of the guide catheter for NET is thought to be the risk of the thromboembolic events. We have developed an idea for inventing the monitoring system of the continuous irrigation through the guide catheter. We herein present a unique invention of the guide catheter irrigation monitoring device.MethodsWe have developed ideas for preventing the thrombotic occlusion of the guide catheter. In order to design a convenient device working in the practical use, we have consulted and shared the ideas with the electrical engineers about putting the invention.ResultsThe guide catheter irrigation monitoring device (GCIMD) consisted of three parts of optical sensor, main body and electric adapter. In brief, the basic principles of working of the GCIMD are as follows. The optical sensor is attached to the dripping chamber of the line to irrigation solution. The main body had the small light and speaker to make an alarm sounds. The sensor monitors the dripping of flush solution. If the dripping stops more than three seconds, a warning alarm has been activated. So, the operating physicians can concentrate and check the guide catheter irrigation. After the use of the GCIMD, there was no major thromboembolic complication in conjunction with the thrombotic occlusion of the guide catheter in our institute.ConclusionWe have developed a brilliant invention of the GCIMD for NET.

Ablation Index and Surround Flow Catheter Irrigation: Impedance-Based Appraisal in ClinicalAblation.

This study sought to assess the impact of ablation power and catheter irrigation during clinical radiofrequency ablation using impedance drop. In preclinical studies, ablation power and catheter irrigation are determinants of ablation efficacy. Static 30-s left atrial ablations were delivered in patients undergoing their first atrial fibrillation ablation. Impedance drop during ablation (as a measure of efficacy) was compared using the following: the force time integral (FTI); the FTI-P (a cumulative multiple FTI and ablation power), and ablation index (AI), a weighted algorithm including contact force, power, and duration. Comparison was also made between a conventionally irrigated (SmartTouch [ST]) versus surround flow (STSF) contact force-sensing catheter. We analyzed 1,013 ablations. For both catheters, the Spearman correlation was higher between impedance drop and AI (rho= 0.89 ST, 0.84 STSF) than FTI-P (rho= 0.71 ST, 0.53 STSF) or FTI (rho= 0.77 ST, 0.52 STSF); p<0.0005 for each. STSF ablations had lower minimum catheter tip temperatures (25°C [interquartile range (IQR): 25°Cto 27°C] vs. 35°C [IQR: 34°C to 36°C]; p< 0.005), and lesser impedance drop per FTI or AI (p< 0.005 for both). ForSTSF, impedance drop plateaued sooner than for ST with respect to FTI (184g.s vs. 463g.s) and AI (370AIvs. 430AI). AI is a more complete ablation descriptor than is FTI or FTI-P, reflected by a stronger correlation withimpedance drop. STSF ablations have lower impedance drop per AI or FTI than ST ablations do, suggesting differenttargets should be used if ablating guided by impedance drop with STSF. With ST, ablation beyond 430 AIprovides minimal additional biophysical efficacy, suggesting an upper limit to use for clinical ablation.

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P856Acute safety and efficacy outcome of pulmonary vein isolation with different generations of a multipolar irrigated circular ablation catheter

P856Acute safety and efficacy outcome of pulmonary vein isolation with different generations of a multipolar irrigated circular ablation catheter

P390Comparison of 8-mm and open irrigated tip catheters for cavotricuspid isthmus atrial flutter ablation: results from the FLIGHT study

P390Comparison of 8-mm and open irrigated tip catheters for cavotricuspid isthmus atrial flutter ablation: results from the FLIGHT study

P340The impact of chronic hemodialysis of catheter ablation using open irrigation catheter in patients with atrial fibrillation

P340The impact of chronic hemodialysis of catheter ablation using open irrigation catheter in patients with atrial fibrillation

Current management and clinical outcomes for catheter ablation of atrioventricular nodal re-entrant tachycardia.

Historical studies of ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) have shown high long-term success rates and low complication rates. The potential impact of several recent practice trends has not been described. This study aims to characterize recent clinical practice trends in AVNRT ablation and their associated success rates and complications. Patients undergoing initial ablation of AVNRT between 1 July 2005 and 30 June 2015 were included in this study. Patient demographics and procedural data were abstracted from procedure reports. Follow-up data, including AVNRT recurrence and complications, was evaluated through electronic medical record review. In total, 877 patients underwent catheter ablation for AVNRT. By the last recorded year, three-dimension (3D) electroanatomical mapping (EAM) was used in 36.2%, 43.2% included anaesthesia, and 23.1% utilized irrigated catheters. Long-term procedural success was 95.5%. The use of anaesthesia, 3D EAM, and irrigated ablation catheters were not associated with differences in success. The presence of an atrial 'echo' or 'AH' jump at the end of an acutely successful procedure was not associated with long-term recurrence (P = 0.18, P = 0.15, respectively). Complications, including AV block requiring a pacemaker (0.4%), were uncommon. In a large, contemporary cohort, catheter ablation for AVNRT remains highly successful with low complications rates. The increased use of anaesthesia as well as modern mapping and ablation tools were not associated with changes in clinical outcomes. Further prospective evaluation of such contemporary practices is warranted given the lack of evidence to support their escalating use.

The impact of a structured clinical training course on interns' self-reported confidence with core clinical urology skills.

Undergraduate training in core urology skills is lacking in many Irish training programmes. Our aim was to assess newly qualified doctors' experience and confidence with core urological competencies. A questionnaire survey covering exposure to urology and confidence with core clinical skills was circulated to all candidates. The group then attended a skills course covering male/female catheterisation, insertion of three-way catheters, bladder irrigation and management of long-term suprapubic catheters. The groups were re-surveyed following the course. Forty-five interns completed the pre-course questionnaire (group 1) and 27 interns completed the post-course questionnaire (group 2). 24/45 (53%) had no experience of catheter insertion on a patient during their undergraduate training. 26/45 (58%) were unsupervised during their first catheter insertion. 12/45 (27%) had inserted a female catheter. 18/45 (40%) had inserted a three-way catheter. 12/45 (27%) had changed a suprapubic catheter. 40/45 (89%) in group 1 reported 'good' or 'excellent' confidence with male urinary catheterisation, compared to 25/27 (92.5%) in group 2. 18/45 (40%) in group 1 reported 'none' or 'poor' confidence with female catheterisation, compared to 7/27 (26%) in group 2. 22/45 (49%) in group 1 reported 'none' or 'poor' confidence with insertion of three-way catheters, compared to 2/27 (7%) in group 2. 32/45 (71%) in group 1 reported 'none' or 'poor' confidence in changing long-term suprapubic catheters, falling to 3/27 (11%) in group 2. This study raises concerns about newly qualified doctors' practical experience in urology. We suggest that this course improves knowledge and confidence with practical urology skills and should be incorporated into intern induction.

Evaluation of ablation catheter technology: Comparison between thigh preparation model and an in vivo beating heart

An invivo animal thigh model is the standard technique for evaluation of ablation catheter technologies, including efficacy and safety of ablation. However, the biophysics of ablation in a thigh model may not be similar to a beating heart. The purpose of this study was to compare efficacy and safety of ablation between a thigh preparation model and a beating heart. In 7 swine, radiofrequency ablation using a 3.5-mm open irrigated catheter (ThermoCool Smart Touch) was performed sequentially in a thigh muscle and invivo beating ventricles. Ablation was performed at low (30 W for 40 s) and high (40 W for 60 s) energy settings and at similar contact force. Ablation lesions were scanned in high resolution and measured using electronic calipers. A total of 152 radiofrequency ablation lesions were measured (86 thigh and 66 heart). At low energy, lesion width was greater in the thigh model (12.19 ± 1.8 mm vs 8.99 ± 2.1 mm; P <.001), whereas lesion depth was similar between the thigh and heart (5.71 ± 0.8 mm vs 5.95 ± 1.3 mm, respectively; P=.18). The planar cross-sectional lesion area was greater in the thigh model (thigh 54.8 ± 10.8 mm2 vs heart 43.1 ± 16.1 mm2; P <.001). At the high-energy setting, lesion depth, width, and area were all greater in the thigh model (thigh 91.5 ± 16.8 mm2 vs heart 56.0 ± 15.5 mm2; P <.001). The incidence of steam pop and char formation was similar between the models. The thigh preparation model is a reasonable technique for evaluation of ablation catheter technology; however it often results in overestimation of lesion size, especially at higher energy settings.

Surface electrocardiography characteristics and radiofrequency catheter ablation of idiopathic ventricular arrhythmias originating from the left infero-septal papillary muscles: differences from those originating from the left posterior fascicle.

Distinguishing between ventricular arrhythmias originating from the left ventricular infero-septal papillary muscles (PM) and those from the left posterior fascicle (LPF) by surface electrocardiography (ECG) is very difficult. This study aimed to report the ECG characteristics and radiofrequency catheter ablation of PM and LPF ventricular arrhythmias. A total of 127 patients underwent catheter ablation of idiopathic ventricular arrhythmias originating from the LPF (n = 106; 85 males; 10-70 years) or PM (n = 21; 14 males; 4-68 years) were studied. A three-dimensional electroanatomic system (3D-EAS) was used to aid ablation. PM ventricular arrhythmias had a longer QRS duration (154.4 ± 18.0 vs. 119.7 ± 12.6 ms, P < 0.001) than LPF ventricular arrhythmias. All 7 ventricular arrhythmias with QRS duration >160 ms originated from the PM, whereas all 87 ventricular arrhythmias with QRS duration <130 ms arose from the LPF. In 33 ventricular arrhythmias with QRS 130-160 ms, all 13 with Vi/Vt ≤ 0.85 originated from the PM, and 19 of 20 with Vi/Vt > 0.85 arose from the LPF. Of the 8 PM ventricular arrhythmias patients whose initial ablation was undertaken using a non-irrigated 4 mm-tip catheter, 1 failed and 6 recurred. However, of the remaining 13 ones using an irrigated catheter and the 3D-EAS, all succeeded and 2 recurred. No complications were noted in any patient. PM ventricular arrhythmias could be identified from LPF ventricular arrhythmias by calculation of QRS duration combined with Vi/Vt using ECG.

Endoscopic Ultrasound-Guided Perirectal Abscess Drainage without Drainage Catheter: A Case Series.

A perirectal abscess is a relatively common disease entity that occurs as a postsurgical complication or as a result of various medical conditions. Endoscopic ultrasound (EUS)-guided drainage was recently described as a promising alternative treatment. Previous reports have recommended placement of a drainage catheter through the anus for irrigation, which is inconvenient to the patient and carries a risk of accidental dislodgement. We report four cases of perirectal abscess that were successfully treated with only one or two 7 F double pigtail plastic stent placements and without a drainage catheter for irrigation.

How to Approach Difficult Cases of AVNRT.

Our approach to the ablation of atrioventricular nodal reciprocating tachycardia (AVNRT), the most common supraventricular tachycardia, is as follows: We first attempt ablation in the right atrial posteroseptum anterior to the coronary sinus ostium with a 4-mm non-irrigated tip catheter. If ablation within the triangle of Koch is unsuccessful with radiofrequency (RF), we switch to cryoablation and target a more superior (mid septal) region. We also utilize cryoablation if RF ablation produces transient VA block (absence of retrograde conduction during junctional rhythm) or a fast junctional rhythm (<350msec). If cryoablation were to fail, or is not available, we would then suggest ablation within the coronary sinus targeting the roof (2-4cm from the os) using a 3.5-mm irrigated tip catheter. If tachycardia were still inducible despite these measures, we would then proceed with transseptal puncture (given our greater experience with this over a retrograde aortic approach) and perform RF ablation along the posteroseptal left atrium and inferoseptal mitral annulus utilizing an irrigated tip catheter. In our experience, cryoablation reliably results in elimination of the slow pathway. The only left atrial ablation for AVNRT at our institution in the past year was performed because a patent foramen ovale allowed for rapid left atrial access, facilitating left atrial ablation of the slow pathway.

Predictors of acute inefficacy and the radiofrequency energy time required for cavotricuspid isthmus-dependent atrial flutter ablation.

Although cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) ablation is a highly efficacious treatment, a bidirectional CTI block cannot be achieved in some patients. In this study, we sought to determine the predictors of acute inefficacy of CTI-AFL ablation and the predictors of the radiofrequency (RF) energy time required to achieve a complete bidirectional CTI block. All consecutive patients who underwent stand-alone CTI-AFL ablation in our institution, except patients with congenital heart disease, were included in this retrospective study. Clinical, echocardiographic, and ablation data were collected from the Arrhythmia Unit and Imaging Unit databases and medical charts. Three hundred and fifty-five patients, with a mean age 63 ± 12years, were included. The ablation was acutely inefficacious in 30 patients (9%). Tricuspid regurgitation was the only independent predictor of acute inefficacy of CTI-AFL ablation (OR 3.161, 95% CI 1.084-9.220, p = 0.035) and was associated with a longer RF time required to achieve CTI bidirectional block (p = 0.031). Age was inversely correlated with the RF time required to achieve a bidirectional CTI block (r = -0.133, p = 0.025). A previous CTI RF ablation, chronic obstructive pulmonary disease (COPD), the use of an irrigated catheter, and advanced age were the independent predictors for requiring less RF energy time to achieve a bidirectional CTI block. Tricuspid regurgitation is associated with less acute efficacy in CTI-AFL ablation. Prior CTI ablation, COPD, use of an irrigated catheter, and advanced age are independent predictors for needing less RF energy time to achieve a complete bidirectional CTI block.

The relationship between oesophageal heating during left atrial posterior wall ablation and the durability of pulmonary vein isolation.

During ablation of the posterior wall (PW), luminal oesophageal temperature elevation (OTE) prompts attenuation of radiofrequency (RF) energy delivery to minimize oesophageal injury. This strategy on lesion efficacy is unknown. The goal of this study was to analyse the relationship between OTE and pulmonary vein reconnection (PVR). During the index antral pulmonary vein (PV) isolation procedure with an irrigated RF ablation catheter, OTE was detected with a multisensor oesophageal temperature probe. Posterior wall ablation did not exceed 25 W and was terminated when the temperature was ≥38.5°C. Patients undergoing redo procedures (n = 142) were studied for PW sites of PVR along 4 segments: left and right superior, and left and right inferior. Pulmonary vein reconnections had occurred in 51 of the 142 patients (36%), in 58 of 284 PV pairs (20%). Among these 58 reconnected pairs, 83% (n = 48) were along the PW. Oesophageal temperature elevation had occurred in 30 patients (59%). No difference in characteristics was seen between the patients with OTE (n = 30) and those without (n = 21). For superior segments, there was no interaction between the presence or absence of OTE and PVR. For inferior segments, there were more PVRs in the group with OTE: for the right-inferior segment, the PVR rate was 72% for OTE cases vs. 42% without (P = 0.04), and for the left-inferior segment, the PVR rate was 44% for OTE cases vs. 22.9% without (P = 0.12). Pulmonary vein reconnections are predominantly posteriorly located. Along the right- and left-inferior PW segments, there was an association with elevated oesophageal temperature during the index procedure.

Radiofrequency Catheter Ablation Targeting the Vein of Marshall in Difficult Mitral Isthmus Ablation or Pulmonary Vein Isolation.

The ligament of Marshall may hinder the creation of mitral isthmus (MI) block or pulmonary vein (PV) isolation (PVI) in radiofrequency (RF) catheter ablation of atrial fibrillation (AF). We aimed to assess the benefit of RF ablation targeting the vein of Marshall (VOM) in failed cases of MI block or PVI. We reviewed the medical records of patients who underwent RF ablation targeting the VOM after failed MI ablation or left PVI using the conventional method, which included circumferential point-by-point ablation around the PV antrum and carina for PVI, and endocardial MI and epicardial distal coronary sinus (CS) ablation for MI block. The VOM was identified by using selective VOM venography with an external irrigation RF ablation catheter. RF ablation targeting the VOM was performed with RF application at the ostium of the VOM inside the CS or at the endocardial region facing the VOM course. During the set period, CS venography was performed in 42 patients after failure of left PVI (n = 5) or MI block (n = 37). Under CS venography, the VOM was visualized in 22 of 42 patients (MI = 19 and PVI = 3). During selective venography of the VOM, no procedure-related complication was observed. RF application targeting the VOM successfully achieved MI block in 13 patients (68.4%) and PVI in 2 patients (66.7%). Selective VOM venography using an irrigated ablation catheter is feasible and safe. RF ablation targeting the VOM may provide additional benefit in failed cases of MI block or PVI.

Ablation of Atrioventricular Nodal Reciprocating Tachycardia in Pregnancy with an Irrigated Catheter and Non-fluoroscopic Mapping System

We describe the case of a pregnant woman with an adenosinerefractory, poorly tolerated atrioventricular nodal reciprocating tachycardia (AVNRT), and successfully treated by RF ablation using an electroanatomical mapping system without radiation exposure. The procedure with the use of the navigation system associated with an irrigated catheter results in a possibility of definitive resolution of the tachycardia in absolute safety for the patient and for the fetus.

Left Atrial Appendage Volume and Plasma Docosahexaenoic Acid Levels Are Associated With Atrial Fibrillation Recurrence After Catheter Ablation.

BackgroundRisk factors for atrial fibrillation (AF) recurrence in patients who have undergone AF catheter ablation have not been fully clarified. The objective of this study was to assess whether the left atrium (LA) and LA appendage (LAA) volumes, and cardio-metabolic markers such as polyunsaturated fatty acids (PUFAs) levels were associated with AF recurrence.MethodsSeventy-seven consecutive patients with AF (mean age, 59 ± 8 years; male, 81%; paroxysmal AF, 64%) undergoing catheter ablation were enrolled. Using contrast-enhanced cardiac multi-detector computed tomography (MDCT) scan, the LA and LAA volume and orifice area were assessed. Radiofrequency ablation was performed by an irrigation catheter, initially targeting the pulmonary veins with a wide area circumferential ablation.ResultsPatients with AF recurrence (36%) exhibited both larger LAA volumes and an LAA orifice area than those without AF recurrence, whereas the LA diameter and LA volumes were not significantly different. Notably, AF recurrence occurred in all patients with a large LAA (≥ 25 mL), and the LAA volume was significantly and negatively associated with docosahexaenoic acid (DHA) levels (β = -0.33, P = 0.003). A multiple regression analysis revealed that the log N-terminal proB-type natriuretic peptide and plasma DHA levels were independent factors for the LAA volume when adjusted for age, AF detected age, left ventricular (LV) ejection fraction, end-systolic LV diameter.ConclusionsThese results suggest that the association between LAA volume and low plasma DHA levels may be an important factor for post-ablation AF recurrence.