Externalization Of Conductor Cables Research Articles

Canadian Registry of Implantable Electronic Device Outcomes: Surveillance of the Riata Lead Under Advisory.

The Riata lead under advisory has posed a unique clinical scenario where inside-out abrasion results in externalization of conductor cables, with a higher risk of electrical failure. We developed a comprehensive registry to assist with clinical management of this lead. This Canadian registry reports the findings of 3763 (74.2% of all Riata leads in Canada) Riata leads under advisory, with a mean follow-up time of 8.9±1.5 years. The overall electrical failure rate was 5.2% at 8 years, with no difference between 7-French and 8-French lead models. Cable externalization was found to be more common in the 8-French model (12.3% versus 5.2%, P<0.0001) and was associated with a higher risk of electrical failure. Predictors of electrical lead failure included cable externalization, higher left ventricular ejection fraction, younger age, higher body mass index, and a passive fixation lead. One patient died due to electrical failure, a further 2 patients survived an event where the device failed to deliver high-voltage therapy. Major complications because of lead extraction were higher when compared with lead abandonment, no difference among lead model observed. Two deaths occurred as a consequence of lead extraction, in the context of an underlying infection. The Riata lead under advisory has a steady electrical failure rate over time. There are identifiable predictors of lead failure that can assist with clinical decisions as to whether lead revision should be performed prophylactically.

What did we learn from Riata™?

The Riata™ 8 French (Fr) and Riata ST™ 7 Fr families of silicone leads have experienced a specific form of insulation abrasion characterized by externalization of conductor cables outside the lead body. Design differences between the 8 Fr and 7 Fr leads make conductor externalization less likely in the smaller diameter lead. The Riata Lead Evaluation Study (RLES) reported on the prevalence of externalized conductors (EC) in patients implanted with Riata™ and Riata ST™ silicone leads and provided details on the incidence of electrical abnormalities in Riata™ and Riata ST™ leads with and without EC. The prevalence of EC was significantly lower for the Riata ST™ leads (7 Fr) as compared with Riata™ leads (8 Fr) (24/259 (9.3 %) vs. 125/517 (24.2 %), P < 0.001), and the majority of leads with EC were not associated with electrical malfunction. The aim of this manuscript is to describe the design of the Riata™ and Riata ST™ families of leads, provide details regarding the mechanisms and rates of lead failure, and discuss recommendations for patient management.

Differential Lead Component Pulling as a Possible Mechanism of Inside‐Out Abrasion and Conductor Cable Externalization

Conductor cable externalization with protrusion (CCE*) is highly prevalent among the Riata 8F and ST 7F defibrillation (DF) leads and infrequently present in the QuickSite and the QuickFlex coronary sinus (CS) leads (St. Jude Medical, Sylmar, CA, USA). A model for CCE* based on differential lead component pulling and conjugate extension with reciprocal compression-bending was developed. Extension of a proximal lead body segment by pectoral or cardiac movements causes reciprocal compression-bending of a distal lead body segment mediated by inextensible conductor cables running down a lead body fixed at various points by fibrous adhesions. The "sawing" action of these cables under tension causes inside-out abrasion of insulation leading to CCE*. DF leads from different manufacturers and the QuickFlex and QuickFlex μ CS leads were subjected to simulated differential pulling. Restitution from differential pulling followed three patterns: complete, partial without escalation, and incomplete with escalation. Only the last pattern (only shown by the Riata 8F and ST 7F leads) was associated with an increased risk to CCE*. For CS leads, deformation concentrated on the more flexible segment when the lead body did not have a uniform construction. The Durata, Riata ST Optim, QuickFlex μ, and Quartet leads should be relatively immune to CCE*. The Durata leads are extremely resistant to longitudinal deformation and probably cause mediastinal displacement rather than differential pulling in response to pectoral movements in vivo. Implantation techniques and lead designs can be used to minimize the risk of CCE*. A bench test for CCE* can be constructed.

Prevalence and Presentation of Externalized Conductors and Electrical Abnormalities in Riata Defibrillator Leads After Fluoroscopic Screening

Background— The Riata family of implantable cardioverter-defibrillator (ICD) leads is prone to a specific insulation abrasion characterized by externalization of conductor cables. The objective of this study was to determine the prevalence of externalized conductors and electrical abnormalities in Riata ICD leads by fluoroscopic screening and standard ICD interrogation. Methods and Results— All ICD implantation centers were contacted by the Netherlands Heart Rhythm Association Device Advisory Committee to identify all patients with an active Riata ICD lead and to perform fluoroscopic screening of the lead. In addition, the electrical integrity of the lead was assessed. As of March 1, 2012, data for 1029 active Riata leads were available; 47% of these were 8-F Riata and 53% were 7-F Riata ST. Externalized conductors were observed in 147 leads (14.3%). Proportion of externalized conductors was higher in 8-F Riata compared with 7-F Riata ST (21.4% vs 8.0%; P &lt;0.001). Median time from implantation to detection of externalized conductors was 65.3 months. The estimated rates of externalized conductors were 6.9% and 36.6% at 5 and 8 years after implantation, respectively. Of the 147 leads with externalized conductors, 10.9% had abnormal electrical parameters vs 3.5% in nonexternalized leads ( P &lt;0.001). Conclusions— The prevalence of externalized conductors in Riata leads is significantly high (14.3%) using fluoroscopic screening. The majority of externalized conductors are not detectable with standard ICD interrogation. Screening with fluoroscopy is reasonable.

Standard X‐Ray Is Inadequate for the Identification of Conductor Cable Externalization in Riata Leads

Journal of Cardiovascular ElectrophysiologyVolume 24, Issue 4 p. 471-471 EP Image Standard X-Ray Is Inadequate for the Identification of Conductor Cable Externalization in Riata Leads MARTA PACHÓN M.D., MARTA PACHÓN M.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorMIGUEL A. ARIAS M.D., Ph.D., MIGUEL A. ARIAS M.D., Ph.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorRAUL NADAL R.N., RAUL NADAL R.N. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorJESÚS JIMÉNEZ-LÓPEZ M.D., JESÚS JIMÉNEZ-LÓPEZ M.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this author MARTA PACHÓN M.D., MARTA PACHÓN M.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorMIGUEL A. ARIAS M.D., Ph.D., MIGUEL A. ARIAS M.D., Ph.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorRAUL NADAL R.N., RAUL NADAL R.N. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this authorJESÚS JIMÉNEZ-LÓPEZ M.D., JESÚS JIMÉNEZ-LÓPEZ M.D. Cardiac Arrhythmia and Electrophysiology Unit, Department of Cardiology, Hospital Virgen de la Salud, Toledo, SpainSearch for more papers by this author First published: 29 August 2012 https://doi.org/10.1111/jce.12002Citations: 1 Miguel A. Arias, M.D., Ph.D., Unidad de Arritmias y Electrofisiología Cardiaca, Hospital Virgen de la Salud, Avda. Barber 30, Planta Semisótano 45004, Toledo, Spain. Fax: +34 925265492; E-mail: [email protected] J Cardiovasc Electrophysiol, Vol. 24, p. 471, April 2013. No disclosures. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume24, Issue4April 2013Pages 471-471 RelatedInformation

Detection of high incidence of Riata lead breaches by systematic postero-anterior and lateral chest X-ray in a large cohort

Insulation breaches with externalization of conductor cables have been described for St-Jude Medical Riata™ defibrillation leads. Published data on the incidence of Riata lead abnormalities are quite heterogeneous. The objective of this study was to estimate systematically the prevalence of lead abnormalities using a postero-anterior (PA) and lateral chest X-ray (CXR). From 2002 to 2008, 552 Riata defibrillation leads were implanted at our centre. We evaluated patients for potential insulation breaches. A PA and lateral CXR was obtained. Chest X-rays were reviewed by two electrophysiologists using a zooming function with magnification up to factor 7.5 and were classified as normal or abnormal for the presence of conductor externalization. A total of 284 patients were included. Riata lead models were 1570, 1580, 1582, 1590, 1592, 7000, 7002, and 7022. The total frequency of radiological lead defects was 24.3%. Insulation breaches occurred at zones of major lead curvature. Mean maximal spacing between extruding lead components was 3.6 ± 1.9 mm (range 2.0-12.4). Abnormal CXRs were more frequent in 8F leads (31.4% vs. 6.3%; P < 0.001). Most defects occurred with lead models 1582 (41.2%) and 1580 (31.4%). Mean time since implantation was longer in abnormal leads (6.7 vs. 5.9 years; P < 0.001). Abnormal leads had higher pacing thresholds (1.1 ± 0.8 V vs. 0.9 ± 0.4 V; P = 0.02). The incidence of insulation breach in Riata leads is much higher than quoted by the manufacturer or reported by most of the literature. A PA and lateral CXR with zooming appears adequate to identify lead breaches when reviewed by an electrophysiologist. Riata lead breaches without electrical abnormalities present a management dilemma and will require further studies.