DOI: 10.19102/icrm.2013.040502
ALLON RAFAEL, MD, YASMIN S. HAMIRANI, MD and MICHAEL B. WEST, MD
Division of Cardiac Electrophysiology, Department of Cardiovascular Disease-Internal Medicine, University of New Mexico, Albuquerque, New Mexico and New Mexico Veterans Affairs Health Care System, Albuquerque, New Mexico
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ABSTRACT. In August of 2012 the FDA recommended regular fluoroscopic evaluation of St. Jude's (STJ) Riata and the Riata ST family of leads due to lead failure; however, extraction of these leads, despite exposed conductors in some cases, was not recommended because of risks of surgery. We present a case report of a 69-year-old female with history of non-ischemic cardiomyopathy and biventricular implantable cardioverter-defibrillator (BIV ICD) who presented to the emergency department with cough and was found to have externalization of a right ventricular cable into her pulmonary artery. Using a vascular retrieval forceps snare we applied an original technique to secure the exposed cable during concurrent lead extraction. The proximal portion of the exposed cable loop was secured in the snare and, with control of the proximal end of the cable outside of the body, the extraction device was employed; the entire lead was successfully explanted. Potential sequelae associated with retention and embolization of exposed conductor cables is considerable. ICD lead extraction in the presence of significant lead disintegration and cable exposure also portends significant risk, beyond that associated with routine lead extraction. Our approach illustrates a safe and effective technique in complex lead extraction and highlights the integral role of creativity and innovation in the advancement of medicine as developments in technology continue to present new challenges in patient care.
KEYWORDS. implantable cardioverter-defibrillator, lead extraction, Riata lead, vascular retrieval forceps snare.
The authors report no conflicts of interest for the published content.
Manuscript received March 1, 2013. Final version accepted April 23, 2013.
Address correspondence to: Allon Rafael, MD, University of New Mexico, Division of Cardiac Electrophysiology, Department of Cardiovascular Disease-Internal Medicine, MSC 10-5550, 1 University of New Mexico, Albuquerque, New Mexico 87131. E-mail: arafael@salud.unm.edu
Implantable cardioverter-defibrillator (ICD) lead complications are being increasingly recognized as longer follow-up data for older leads are published.1 Reported failure in Medtronic's Sprint Fidelis lead and St. Jude's (STJ) Riata and the Riata ST family of leads have steadily become part of the literature. Many of them have required lead explantation, which is not without associated risks. Monitoring these patients has proven to be difficult since interrogation may reveal unchanged lead impedances despite exposed conductors.
We report an extreme case of externalized cable due to lead abrasion in a Riata lead and describe a unique, innovative extraction technique performed at our center.
A 69-year-old female with hypertension, dyslipidemia, and non-ischemic cardiomyopathy presented to the emergency department with cough and vague gastrointestinal symptoms. A dual-chamber ICD had been implanted 6 years earlier for primary prevention of sudden cardiac death and was upgraded 3 years later to a biventricular (BIV) device in the presence of left bundle branch block for cardiac resynchronization therapy (CRT).
The patient's presenting heart rate was 69 bpm (BIV paced) and blood pressure was 135/67 mmHg. Her complete blood count, blood chemistry, and liver function tests were within normal limits. A chest X-ray (CXR) was performed, which revealed a foreign body in the right ventricle (RV) tracking up into the right ventricular outflow tract (RVOT) and into the left pulmonary artery (PA). During the hospital stay the patient's abdominal symptoms resolved with conservative management. A transthoracic echocardiogram revealed stable, severe left ventricular systolic dysfunction with an ejection fraction of <20% and no pericardial effusion. The patient's St. Jude dual-chamber BIV-ICD was interrogated—stable atrial and BIV sensing and pacing thresholds as well as lead impedances were detected with a battery life approaching the elective replacement indicator. The patient was brought to the cardiac catheterization laboratory to acquire high-resolution images of the lead system with cine-fluoroscopy; multiple views were obtained in the right and left anterior oblique projection with cranial and caudal skew (Figure A and B). These images enabled clear visualization of the externalized cable from the right ventricular lead near the distal coil at the level of the tricuspid annulus. Tachycardia therapies on the ICD were turned off while bradycardia therapies remained on. Reviewing her previous CXR revealed subtle evidence of an externalized conductor 6 months earlier; a CXR performed 15 months earlier was unremarkable.
Figures A, B: Fluoroscopic images of chest in right anterior oblique projection, cranial and caudal views. Arrows depict right atrial, right ventricular (RV) and coronary sinus leads; the abraded RV lead with externalized cable extending into left pulmonary artery is seen. Figure C–F: Introduction of forceps snare (C); proximal loop of exposed cable is secured in snare (D); exposed cable is retrieved from pulmonary artery, proximal end pulled to extracorporeal position (E, F). Figure G–I: Concurrent extraction of the right ventricular lead and exposed lead cable (proximal end controlled extracorporeally). Figure J: Subclavian venogram (performed prior to lead extraction). Figure K: Coronary sinus venogram. Arrows depict ideal target branch veins in the lateral, mid-basal distribution. Figure L: Final image of biventricular implantable cardioverter defibrillator re-implantation. |
Considering the degree of cable migration, potential thrombus formation or distal detachment from the lead and subsequent embolization, and concern for further externalization of the other lead cables (including high-voltage conductors and potential sequelae), the decision was made to proceed with lead extraction. Owing to the high risk of shearing off the externalized cable associated with conventional lead extraction, potentially resulting in iatrogenic foreign body embolization, we employed an original technique to secure the exposed cable during concurrent extraction. A separate Attain Command 6250-MB2X sheath (7.2 Fr, 50 cm Medtronic Inc., Minneapolis, MN) was delivered into the right heart and a vascular retrieval forceps snare, (3.0 Fr, 120 cm, 10-mm snare, Cook Medical Inc., Bloomington, IN) was subsequently introduced through the sheath to the level of the lead disruption site (Figure C). Judging by the crossing pattern of the exposed loop and taking into account the length of externalized cable it became evident that the proximal portion of the cable represented the detached end. Using the snare, the “free” end was secured, the tip of which remained slightly below the insulation proximal to the abrasion site. The exposed cable was maximally retracted until the free end was retrieved outside of the body and tension was appreciated along the distal end of the cable at the lead tip (Figure D–F). While maintaining control of the proximal end of the cable, the lead lumen was cleared through the distal end with a standard stylet. Subsequently the stylet was removed and the proximal portion of the lead was severed at the neck, distal to the connecting harness. A Bulldog lead extender (70 cm, Cook Medical Inc., Bloomington, IN) was used to secure the remaining internal lead cables and an O Ethibond suture (Ethicon Inc., Somerville, NJ) was fastened around the outer insulation to further secure the lead. A Liberator Beacon tip locking stylet (140 cm, Cook Medical Inc.) was inserted into the lead, and an Evolution Shortie mechanical dilator sheath set (Cook Medical Inc.) was used to gain access into the subclavian vein. Using a standard Evolution mechanical dilator sheath set (9 Fr), the extraction apparatus was then advanced beyond the level of the abrasion and ultimately approached the distal end of the lead. Slack was afforded to the externalized cable (without compromising control) in order to avoid detachment at the distal insertion by the extraction sheath (Figure G). Subsequently both the lead and the cable were pulled back in unison, through separate sheaths as the system was successfully extracted (Figure H). The externalized cable, however, was now looped in the subclavian vein through the two insertion sites and remained connected to the lead outside of the body (Figure I). With control of the proximal and distal ends of the cable the distal end was safely cut from the lead and removed.
Efforts were then directed towards implanting a new BIV-ICD for CRT and defibrillation capacities. Subclavian venous access was again achieved using the standard approach, employing the modified Seldinger technique. An earlier subclavian venogram, performed prior to lead extraction due to challenging access originally, was again utilized for guidance (Figure J).
Coronary sinus (CS) access was then achieved using a 65-cm Viking CS diagnostic decapolar catheter (C.R. Bard, Inc., Murray Hill, NJ), counter clockwise manipulating the 2-5-2 electrode spacing to create a three-dimensional impression in the left anterior oblique projection and subsequently railing a 50-cm Attain Command 6250-MB2X sheath (7.2 Fr, Medtronic Inc., Minneapolis, MN) over the catheter into the CS; this original technique has previously been described in more detail.2 A CS venogram revealed ideal target branch veins in the lateral, mid-basal distribution (Figure K, arrows). The CS lead was successfully delivered followed by implantation of right atrium and RV leads (Figure L). The patient was followed in our device clinic and denied any symptoms with adequate BIV-ICD function on interrogation.
With improved safety in technological advancements, the number of transvenously implanted ICDs has increased rapidly. ICD leads, however, suffer from constant mechanical stress from cardiac contraction and extrathoracic stresses, as well as chemical and oxidative stresses inside the human body. In a study of 900 patients Kleemann et al.3 reported 15% overall lead failure with an annual failure rate of 20% in leads ≥10 years old. Insulation defects accounted for 56% of lead complications. Epstein et al.4 analyzed 7,497 patients, followed for 22 months, where 27 different models of St. Jude Riata leads were implanted. The rates of conductor fracture, insulation damage, dislodgement, and perforation were found to be 0.09%, 0.13%, 0.88%, and 0.31%, respectively.
Unlike other lead failures, STJ Riata and Riata ST leads can experience inside-out abrasions causing externalization of cables without any changes detected on regular device interrogation. In a recent study of 105 Riata leads by Hauser et al.,5 the most common location of insulation defect was distal to the proximal coil; 26.7% had inside-out insulation defects underneath the high-voltage coils; and inappropriate shocks were experienced by 29.5% of patients.
Wires retained in the central venous system of the heart can embolize as a whole or in fragments and can easily reach the pulmonary artery. In our patient the slightly visible externalized cable seen 6 months earlier had migrated significantly and was flailing into the left PA. In a series of 220 documented cases of catheter embolism, the morbidity was 71% and the mortality was 38% if the catheter fragment causing central embolization was not removed.6 Causes of death included pericardial tamponade due to myocardial perforation, thrombosis with subsequent pulmonary embolism, and arrhythmias.
The clinical implications of externalized conductors without electrical anomalies are not fully known or understood at this time. On August 16, 2012, the FDA recommended that physicians image (fluoroscopy or a two-view CXR) Riata and Riata ST leads to assess for externalized conductors and other visible insulation abnormalities; in cases of identified visual insulation abnormalities, it was considered reasonable to repeat interval imaging to assess for progression. The FDA, St. Jude Medical, and the Heart Rhythm Society do not recommend routine removal of leads because of the risks of explantation surgery. Additional studies are needed to help clinicians identify such lead disintegration and provide safe management options for our patients.
Potential sequelae associated with retention and embolization of exposed conductor cables is considerable and increasingly pertinent as the rate of ICD lead defects continues to rise. Extraction in such cases, however, may carry heightened risks beyond those associated with routine lead extraction. In our reporting we offer a safe and effective technique in complex lead extraction with a significantly exposed and perilous lead cable. Our approach illustrates the integral role of creativity, determination, and innovation in the advancement of medicine and invasive therapeutic techniques as developments in technology continue to bring with it new challenges in patient care.
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