Implantation of systems for cardiac resynchronisation: tips and tricks – cardiac surgeon's view
a Department of Thoracic and Cardiovascular Surgery, Heart Centre North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany
b Department of Cardiology, Heart Centre North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany
Received 3 May 2004; accepted 24 May 2004.
* Bert Hansky, Department of Thoracic and Cardiovascular Surgery, Heart Centre North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany. Tel.: +49-5731-970; fax: +49-5731-971820
bhansky{at}hdz-nrw.de
Abstract
Specific problems of cardiosurgical implantation of biventricular devices for cardiac resynchronisation therapy are elucidated elaborately. In particular, the necessity and amount of intraoperative monitoring as well as the appropriate mode of anaesthesia are described. Furthermore, the sequence of lead placement, the technique of coronary sinus intubation using a guiding catheter as well as means to avoid thrombus formation in the coronary sinus are depicted.
Biventricular ICD devices should be implanted from a left sided approach to integrate the device into the defibrillation field and to maintain the option of placing an additional subcutaneous array lead.
It is of particular cardiosurgical interest that coronary vein leads are applicable for ventricular stimulation in patients after tricuspid valve replacement thus avoiding repeated surgical exposure of the heart.
Key Words: Cardiac resynchronisation therapy • Biventricular ICD • Surgical technique • Tricuspid valve replacement
Introduction
The development of specific antibradycardia and antitachycardia devices for cardiac resynchronisation therapy (CRT) as well as the possibility of stimulating the left ventricle by transvenously placed leads has lead to a rapid worldwide acceptance of this therapeutic option in treating patients with severe congestive heart failure (CHF) with a left bundle branch block and wide QRS complex.1–5. This article sheds light to various surgical aspects, relevant for the implanting physician.
Anaesthesiology and patient monitoring
Primarily, the mode of anaesthesia including the amount of intraoperative monitoring has to be chosen with respect to the patients' severely compromised haemodynamic status as well as coronary venous anatomy complicating the implantation procedure itself. Furthermore, comorbodities, especially impaired renal function, have to be assessed. Continuous invasive arterial blood pressure monitoring should be applied routinely as well as the application of a Foley catheter to evaluate urine production throughout the implantation procedure, since a nephrotoxic contrast medium is applied to visualize the coronary venous system. Additionally, patch leads should be applied in all cases to allow external defibrillation. In our experience of 461 coronary venous lead implantations, ventricular fibrillation was induced in 5 patients by manipulating the coronary sinus with the guiding catheter. Two of these patients were scheduled for ICD implantation anyway due to vulnerable ventricles according to MADIT criteria, but in 3 patients without any preoperative signs of malignant ventricular arrhythmias, intraoperative ventricular fibrillation occurred during implantation of an antibradycardia system.
In skilled hands, the implantation of an antibradycardia device might be performed under local anaesthesia in patients with good cardiac function, but in patients with severe CHF and difficult venous anatomy, general anaesthesia should be preferred since prolonged supine position is often not well tolerated . Furthermore, prolonged implantation procedures due to anatomical or technical difficulties in placing the CV lead may result in ineffective local anaesthesia. Therefore, we prefer general anaesthesia in all patients. Patients will only be relaxed shortly for intubation to allow adequate lead testing for the safe detection of a possible phrenic nerve stimulation. A central venous line should be placed to have a suitable access for the administration of inotropic drugs and volume and for continuous on-line haemodynamic monitoring.
Surgical technique
A left sided surgical access is strongly recommended for the implantation of biventricular ICD devices, since the surgical route to the coronary sinus is C-like resembling the preformed curve of the tools and leads, whereas the right sided surgical route is Z-like opposing the natural curve of the hardware. Furthermore and most important, the left sided approach is more advantageous to include the ICD into the defibrillation field ("active can") itself.6 Additionally, in patients with extremely distended ventricles suitable for CRT, the implantation of subcutaneous array leads has to be considered to achieve adequate defibrillation thresholds (Figs. 1(a) and (b)).6,7 Four of 345 patients eligible for biventricular ICD devices had to be provided with additional array leads which is a threefold increase to the normal ICD cohort. In more than 1,000 patients receiving an ordinary ICD, array leads had to be added only once. According to the inclusion criteria of CRT patients, left ventricles were massively enlarged reaching beyond the standard defibrillation field, which made an appropriate termination of ventricular fibrillation impossible.
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After skin incision in the left deltoid pectoral groove, subcutaneous or subpectoral pockets for ICD implantation as well as three isolated accesses to the venous system are created. We routinely use the cephalic vein for atrial and right ventricular lead placement while the most medial access to the subclavian vein is reserved for the implantation of the CV lead. Thus, the implantation even in tall patients with very distal lead positioning in the coronary venous system is not affected by the length of commercially available guiding catheters. Furthermore, different accesses reduce the risk of proximal lead adhesions with secondary lead dislocation.
Most surgeons begin the procedure by implanting the right ventricular lead to avoid a complete AV block induced by manipulation at the coronary sinus ostium (personal communication). This is our approach in patients with a preoperative AV block only. If a complete AV block requiring immediate secure RV pacing is not imminent, we commence the procedure by placing the CV lead to avoid twiddling of the leads which results in a more undisturbed intracardiac visualization and thus facilitates the implantation procedure. Electronic data of the CV lead are obtained and phrenic nerve stimulation is excluded prior to the placement of the remaining leads before surgery is terminated as described in literature.
To achieve an adequate stability of the guiding catheter during CV lead implantation, it has to be advanced at least 4–5 cm into the coronary venous system (Fig. 2). A six-French electrophysiology catheter has also proved to be very useful. The preformed curve of the guiding catheter can be adjusted according to the individual anatomy of the coronary sinus and correct placement of the guiding catheter can be achieved quickly with low risk of CS injury. If the target vein is next to the coronary sinus ostium, this technique is suitable for superselective intubation of the vein by the guiding catheter itself (Fig. 3).
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Intraoperative anticoagulation
In patients with preoperative Warfarin anticoagulation, an INR up to 2.5 is tolerated and will be resumed postoperatively on postoperative day 1. In patients with an alloprosthesis, especially in tricuspid position, an INR up to 3.0 is acceptable. Even multiple punctuations of the subclavian vein in selected cases did not lead to any haemorrhagic complication.
Interestingly, patients converted to systemic heparin, faced an increased risk of bleeding into the pacemaker pocket.
Patients without adequate anticoagulation receive 100 U/kg BW heparin i.v. to reduce the risk of thrombus formation inside the catheter and the coronary venous system (Fig. 4).
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Management of stenotic veins
In 5 patients the target vein was severely stenotic so that lead implantation could only be achieved after vigorous interventional vein dilatation. In one case, the stenosis was created by an earlier implanted lead being in place for more than one year, while in 3 patients an aorto-coronary bypass graft was placed to the adjacent obtuse marginal coronary artery leading to scarred venous obstruction. Scarred obstruction can easily be relieved by a common balloon dilatation. However, stenoses created by suture lines after coronary artery bypass grafting (CABG) can only be opened by a "cutting balloon" described primarily by Worley (personal communication).
CV leads after tricuspid valve replacement
Another important cardiosurgical aspect is the possibility to stimulate patients after tricuspid valve replacement with transvenously implanted coronary vein leads.8 In our cohort of 21 patients stable electrical thresholds for left ventricular stimulation were observed up to 4 years even after repetitive cardiosurgical interventions.9 These patients are mostly pacemaker dependent so that a secure lead position is mandatory. In contrast to CRT, lead placement in an anterior vein is acceptable in this cohort, since the ventricles perform synchronously and therefore do not need to be resynchronised (Figs. 5(a) and (b)).
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Peri- and postoperative antibiotic therapy
The guidelines of the European Society of Cardiology (ESC) on the prevention, diagnosis and treatment of infective endocarditis (IE) do not recommend a perioperative, prophylactic therapy in pacemaker and ICD implantation per se. Instead, patients with alloprosthetic valve replacement, high grade mitral valve regurgitation and diabetes mellitus face an increased risk of IE and should be treated according to the guidelines. Personal communication at the 14th World Congress in Cardiac Electrophysiology and Cardiac Techniques (Cardiostim 2004) has revealed that 66% of implanting cardiologists and surgeons perform a systemic or topical antibiotic prophylaxis when implanting CRT devices. In 20% a single shot broad spectrum therapy is performed whereas the remaining physicians perform a 3- to 5-day therapy up to the removal of the central venous line. Thus, the infection rate could be reduced to less than 1%.
Analogous to the ESC guidelines to prevent IE after heart valve surgery, a prophylactic antibiotic therapy in CRT patients should be applied prior to further procedures with an increased risk for bacteraemia.
Summary
- In patients with severe CHF, general anaesthesia is recommended for the implantation of a CRT device. The amount of intraoperative monitoring has to be adjusted accordingly.
- To ensure immediate external defibrillation perioperatively, patch leads should be placed in all cases.
- Preoperative oral anticoagulation does not lead to increased haemorrhage which is the case with intermittent change to systemic heparinisation.
- To prevent postoperative emboli by coronary venous thrombi in non-anticoagulated patients, a single systemic application of heparin (100 U/kg) is recommended.
- In patients with left bundle branch block, ventricular synchrony can only be achieved by CV lead placement in either posterolateral or lateral veins, while permanent stimulation via the anterior vein is a therapeutic option for patients after tricuspid valve replacement.
- A perioperative antibiotic prophylaxis is recommended and performed by most surgeons in Europe. The ESC guidelines for IE should be considered appropriately.
References
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- Stellbrink C, Auricchio A, Diem B, et al. Potential benefit of biventricular pacing in patients with congestive heart failure and ventricular tachyarrhythmia. Am. J. Cardiol. 1999;83:143D–150D[Web of Science][Medline]
- Conti JB. Biventricular pacing therapy for congestive heart failure: a review of the literature. Cardiol. Rev. 2001;9:217–226[CrossRef][Medline]
- Pappone C, Santinelli V. Heart failure. The pacing therapy. Minerva Cardioangiol. 2003;51:179–184[Medline]
- Abraham WT. Rationale and design of a randomized clinical trial to assess the safety and efficacy of cardiac resynchronization therapy in patients with advanced heart failure: the Multicenter InSync Randomized Clinical Evaluation (MIRACLE). J. Card. Fail. 2000;6:369–380[CrossRef][Web of Science][Medline]
- Gradaus R, Block M, Seidl K, et al. Defibrillation efficacy comparing a subcutaneous array electrode versus an "active can" implantable cardioverter defibrillator and a subcutaneous array electrode in addition to an active can implantable cardioverter defibrillator: results from active can versus array trials I and II. J. Cardiovasc. Electrophysiol. 2001;12:921–927[Medline]
- Gradaus R, Hammel D, Kotthoff S, et al. Nonthoracotomy implantable cardioverter defibrillator placement in children: use of subcutaneous array leads and abdominally placed implantable cardioverter defibrillators in children. J. Cardiovasc. Electrophysiol. 2001;12:356–360[CrossRef][Web of Science][Medline]
- McGavigan AD, Morley-Davis A, Hogg KJ, et al. Coronary sinus pacing in an elderly patient with Bjork-Shiley tricuspid valve replacement. Scott. Med. J. 2001;46:148–149[Medline]
- Hansky B, Gueldner H, Vogt J, et al. Coronary vein leads for cardiac pacing in patients with tricuspid valve replacement. Thorac. Cardiovasc. Surg. 2002;50:120–121[Medline]
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