Implante de electrodos epicárdicos en el ventrículo izquierdo para resincronización mediante cirugía mínimamente invasiva asistida por videotoracoscopia

Thoracoscopic Approach to Epicardial Lead Implantation in Adult Patients with Previous Congenital Cardiac Surgery

Background

Substantial technical challenges exist in placing transvenous pacing leads in the heterogeneous adult congenital heart disease patient population. Anatomical issues including occlusion of central veins, single ventricle physiology, and lack of transvenous access to systemic right ventricles, often require thoracotomy for epicardial lead placement.

Methods

We assessed the feasibility of performing a totally thoracoscopic approach to epicardial pacing lead implantation in 10 adult patients (mean age 32.5 years) with congenital heart disease. The underlying cardiac anatomy consisted of transposition of the great arteries, status post (s/p) Mustard procedure (3); tricuspid atresia, s/p Fontan procedure (3); congenitally corrected transposition (1); Ebstein's anomaly, s/p tricuspid valve replacement (1); AV canal, s/p repair (1); and hypertrophic cardiomyopathy, s/p myomectomy (1). Twenty-six previous cardiac operations (mean 2.8 per patient) had been performed in this group.

Results

Indications for thoracoscopic lead insertion included primary rhythm disturbances, progressive heart failure with a QRS>120 milliseconds, and an unapproachable coronary sinus or failed transvenous lead insertion. All patients underwent thoracoscopic implantation of 2 epicardial leads to the systemic ventricle and generator insertion. Intraoperative transesophageal echocardiography (TEE) was used in all cases, which facilitated port placement. Measurements at operation showed mean threshold of 2.0V (95% CI 0.9–3.1V at 0.5 milliseconds) and a mean impedance of 1259 Ohms (95% CI 418–2100). There were no procedural related complications and no patient required conversion to an open procedure. Seventy percent of patients were extubated immediately after the procedure and were discharged from the intensive care unit within 24 hours. There was 1 noncardiac death due to gastrointestinal ischemia.

Conclusion

Adults with congenital heart disease present significant challenges to pacing lead implantation including variability of the location of the systemic ventricle, coronary sinus anatomy, right-sided valve replacement, a small thoracic cavity, limited vascular access, and adhesions from prior cardiac procedures. Additionally, thoracoscopy has been previously considered a contraindication in this subgroup of patients. However, we have demonstrated that with careful preoperative planning and the assistance of TEE, a totally thoracoscopic approach to epicardial lead implantation is both feasible and safe.

Surgical Aspects of Cardiac Resynchronisation Therapy

Despite significant advances in the pharmacological treatment of heart failure, rates of mortality and morbidity from the condition remain a concern. The introduction of cardiac resynchronisation therapy (CRT) has been a welcome addition to the treatment strategy of patients who display ventricular dyssynchrony. Several control studies have shown significant benefits from this intervention in particular improved mortality and reduction in symptom burden. In this short review, we focus on several concepts of CRT and discuss the implications of surgical implantation of the left ventricular (LV) lead as compared to the standard transvenous approach.

Video-Assisted Implantation of a Left Ventricular Lead and Intrathoracic Tunneling to a Right-Sided CRT-D Device

We describe two cases in which a biventricular implantable cardioverter defibrillator for cardiac resynchronization therapy had to be placed on the right side due to unsuitability of the left subclavian vein. Endocardial implantation of a left ventricular lead through the coronary sinus was previously attempted but was unsuccessful. Implantation of the epicardial left ventricular pacing lead was performed through video-assisted thoracic surgery on the left side. The connector end of the left ventricular pacing lead was tunnelized through the anterior mediastinum into the right pleural space. The right-sided pocket was then opened. A tunnel was created from the pocket to the thoracic wall, and the pleural space was entered over the second rib. The lead was retrieved from the right pleural space and connected with the Cardiac resynchronization therapy-device (CRT-D). Both procedures and postoperative periods were uneventful. Intrathoracic left-to-right tunneling of an epicardial left ventricular lead by video-assisted thoracic surgery is feasible and safe. It provides an alternative to subcutaneous tunneling.

Thoracoscopic left ventricular lead implantation in cardiac resynchronization therapy

Cardiac resynchronization therapy is known to reduce morbidity and mortality in patients with advanced heart failure as a result of dyssynchrony and systolic dysfunction of the left ventricle. Placement of the left ventricular (LV) lead via the coronary sinus can be difficult. When LV lead implantation is difficult, a video-assisted epicardial approach can be a good alternative. Although there are several reports of video-assisted epicardial LV lead implantation, mini-thoracotomy and lead implantation under direct vision have been used in most series. A 49-yr-old woman with dilated cardiomyopathy underwent the video-assisted epicardial LV lead implantation because percutaneous transvenous approach was difficult due to small cardiac veins. The patient was discharged without problems and showed improved cardiac function at the 3 follow-up months. We report the first successful total thoracoscopic LV lead implantation (without mini-thoracotomy) in Korea.

Midterm Follow-up of Robotic Biventricular Pacing Demonstrates Excellent Lead Stability and Improved Response Rates

BACKGROUND

: Robotically assisted left ventricular (LV) lead placement is an effective minimally invasive rescue procedure for cardiac resynchronization in the setting of failed coronary sinus lead insertion. The long-term response rate and durability of this technique has not been reported. The authors evaluated the midterm outcome of biventricular pacing performed with robotically placed LV leads.

METHODS

: Forty-two patients underwent implantation of LV epicardial leads using robotic assistance and the posterior approach. Half of the patients had prior cardiac surgery. All leads were placed in an optimal site along the posterolateral surface of the LV. The patients were prospectively followed up for clinical response, LV reverse remodeling, and LV lead stability over a mean period of 16.7 ± 9.5 months (range, 3-34 months). A multivariate Cox proportional hazards model was used to determine predictors of response.

RESULTS

: All patients had successful LV lead placement with no postoperative mortality. Statistically significant improvements in left ventricular ejection fraction, NYHA heart failure class, systolic left ventricular internal dimension index, and diastolic left ventricular internal dimension index. The 3-month clinical response rate was 81% and dropped to 71% at average maximal follow-up. Multivariate analysis of 9 variables revealed only LVEF greater than 15% and absence of pulmonary hypertension to be predictors of response. No difference in operative time, response rate, or LV lead stability was detected when primary versus reoperative cases were compared.

CONCLUSIONS

: Robotic LV lead placement is a reliable technique for optimal lead placement with durable long-term results.

Cardiac resynchronization therapy: redefining the role of device therapy in heart failure

That cardiac dyssynchrony can contribute to a decline in cardiac efficiency has been recognized in one form or another for at least 50 years. Although revascularization and beta-blockers can improve cardiac synchrony, there was little interest in or awareness of this clinical entity until the advent of specific, highly effective therapy using atriobiventricular pacing, often described as cardiac resynchronization therapy. Over the last few years, significant advances in cardiac resynchronization therapy technology and the publication of large-scale clinical trials using cardiac resynchronization therapy devices in patients with heart failure have led to the widespread use of these devices. This review will briefly describe the complex nature of cardiac dyssynchrony, what is known about its epidemiology, the effects of cardiac resynchronization therapy, appropriate patient selection, practical aspects, such as implantation and monitoring, and some still unanswered questions.