Carotid stent fracture: diagnosis and management.

With increasing numbers of carotid stent implantations, stent fractures likely will be detected in this vessel region. The authors report two cases of stent fracture: one balloon expandable and one self expandable stent fractured and caused symptoms. CT angiography identified the stent fractures. One partial stent fracture in the internal carotid artery caused a significant restenosis. One complete stent fracture in the common carotid artery caused neurological symptoms, but no significant restenosis. Computerized tomographic angiography (CTA) findings were confirmed by conventional angiography and treated by repeated stent implantation. In a 12-month follow-up period, both patients remained further neurologically asymptomatic and there was no restenosis in duplex sonography or CTA.

Accuracy of integration of multislice computed tomography imaging into three-dimensional electroanatomic mapping for real-time guided radiofrequency ablation of left atrial fibrillation-influence of heart rhythm and radiofrequency lesions.

Circumferential radiofrequency ablation around the orifices of the pulmonary veins is a curative catheter-based therapy of paroxysmal and persistent atrial fibrillation (AF). Three-dimensional cardiac image integration is a promising new technology to visualize the complex left atrial anatomy and neighbouring structures. This study aimed to validate the accuracy of integrating multislice computed tomography (MSCT) into three-dimensional electroanatomic mapping (EAM) to guide radiofrequency catheter ablation (CA) of AF. Forty consecutive patients (34 male, mean age 56 +/- 10 years) with multidrug-resistant AF underwent 16-slice MSCT 1 day before radiofrequency CA. MSCT data were processed and imported to the Cartotrade mark EAM system. Using the CartoMergetrade mark Image Integration Module, the generated EAM was aligned with the MSCT images. An integrated statistical algorithm provided information about the accuracy of the fusion process. In every single patient, MSCT images could be aligned with the EAM. Mean distance between the EAM points (n = 63 +/- 14) and the MSCT surface was 1.6 +/- 1.2 mm with no difference between sinus rhythm versus AF (p = 0.145) and no distinction between patients in paroxysmal versus persistent/permanent AF despite a significant difference in left atrial diameters. An average of 388 +/- 81 radiofrequency ablation points were taken within the procedures resulting in a mean distance of 2.3 +/- 1.8 mm between the EAM points and the MSCT image after the ablation procedure. There was a significant difference of alignment accuracy before and after radiofrequency CA (p < 0.001). MSCT images can be accurately integrated into three-dimensional EAM. Pre-interventional cardiac rhythm does not influence the precision of fusion. Accuracy of fusion deteriorates after radiofrequency CA.

Identification of a high-risk population for esophageal injury during radiofrequency catheter ablation of atrial fibrillation: procedural and anatomical considerations.

BACKGROUND: Atrioesophageal fistula is an uncommon but life-threatening complication of atrial fibrillation (AF) ablation. Esophageal ulcerations (ESUL) have been proposed to be potential precursor lesions. OBJECTIVE: The purpose of our study was to prospectively investigate the incidence of ESUL in a large patient population undergoing radiofrequency catheter ablation (RFA). Additionally, we aimed to link demographic data and lesion sets with anatomical information given by multislice computed tomography imaging and to correlate these data with the development of ESUL. METHODS: This study included 267 patients and consecutively screened all individuals for evidence of ESUL 24 h after RFA of AF by endoscopy of the esophagus. A standardized ablation approach using a 25-W energy maximum at the posterior left atrial (LA) wall without esophagus visualization, temperature monitoring, or intracardiac ultrasound was performed. RESULTS: In total, we found 2.2% of patients (6 of 267) presenting with ESUL. Parameters exposing a specific patient to risk of developing ESUL in univariate analysis were persistent AF (5 of 95, P = .023), additional lines performed (roofline: 6 of 114, P = .006; LA isthmus: 4 of 49, P = .011; coronary sinus: 5 of 66, P = .004), and LA enlargement (P = .001) leading to sandwiching of the esophagus between the LA and thoracic spine. Multivariate analysis revealed LA-to-esophagus distance as the only significant risk factor. CONCLUSION: This study is the first to link anatomical information and procedural considerations to the development of ESUL in radiofrequency ablation for AF. Furthermore, it reveals the correlation and individual impact of these factors. Not a single patient with pulmonary vein isolation alone developed ESUL.

Impact of integration of multislice computed tomography imaging into three-dimensional electroanatomic mapping on clinical outcomes, safety, and efficacy using radiofrequency ablation for atrial fibrillation.

BACKGROUND: Circumferential radiofrequency catheter ablation (RFCA) around the orifices of the pulmonary veins (PV) is a curative catheter-based therapy of paroxysmal, persistent, and permanent atrial fibrillation (AF). Integration of multislice computed tomography into three-dimensional electroanatomic mapping to guide catheter ablation has been shown to be accurate and feasible. This study investigated whether the use of such sophisticated imaging technology translates into better clinical outcomes, procedural efficacy, and safety in comparison with a control group treated with conventional three-dimensional electroanatomic mapping. METHODS: A total of 100 consecutive patients (85 male, mean age 55 +/- 9 years) with multi-drug-resistant AF underwent RFCA. In this study we used a wide area circumferential approach with confirmed PV isolation (requiring additional ablations at the ostial level) and further lines as needed. RESULTS: Comparison of outcome data between the conventional electroanatomic mapping (Carto XP, Biosense Webster, Diamond Bar, CA, USA) and the image integration technology (Carto MERGE, Biosense Webster) resulted in a significant improvement in procedural success for the image integration group (85.1% vs 67.9%; P = 0.018). No single case of significant PV stenosis occurred in the Carto MERGE group versus three significant stenoses in the conventional group (P = 0.098). Both procedure and fluoroscopy times remained unchanged. CONCLUSION: Multislice computed tomography image integration into electroanatomic mapping significantly improves the success of wide area circumferential ablation with confirmed isolation of the PV and additional lines. In addition, the safety of radiofrequency ablation with regard to the occurrence of PV stenosis is increased in comparison with a control group using conventional electroanatomic mapping alone. Procedural efficacy remains unchanged.