SUBPECTORAL IMPLANTATION OF ICD GENERATORS - LONG-TERM FOLLOW-UP

A nonthoracotomy surgical approach using an endocardial electrode and combined implantation of a subcutaneous patch and the implantable card ioverter defibrillator (ICD) generator in a subpectoral pocket has bee n described. We report the long-term follow-up results in patients und ergoing implantation using this approach. The patient population consi sted of 28 patients (22 men and 6 women) with a mean age of 59 +/- 12 years. The underlying heart disease consisted of coronary artery disea se in 20 patients and dilated cardiomyopathy in 8 patients. Sustained ventricular tachycardia was the mode of presentation in 16 patients an d sudden cardiac death in 12 patients. The mean left ventricular eject ion fraction was 31% +/- 6%. The lead system consisted of an 8 French bipolar passive fixation rate sensing lead positioned at the right ven tricular apex, an 11 French spring coil electrode positioned at the su perior vena cava-right atrial junction (surface area 700 mm(2)), and s ubmuscular placement of a large patch (surface area 28 cm(2)) on the a nterolateral chest wall near the cardiac apex via a submammary incisio n. A defibrillation threshold of less than or equal to 15 joules (J) w as required for implantation. This criterion was not satisfied in five patients; thus, a limited thoracotomy was performed via the submammar y incision, and the large patch was placed epicardially. The mean R wa ve amplitude was 12 +/- 3 mV, the mean pacing threshold was 1.0 +/- 0. 5 V at 0.5 msec, and the mean defibrillation threshold was 12.6 +/- 3 J. ICD generators implanted were the Ventak-P in 17, PCD-7217 ill 5, a nd the Cadence V-100 in 6 patients. These patients have been followed for a mean of 14.6 +/- 6 months. There was no perioperative mortality, and none of the patients developed an infection during follow-up. Gen erator migration or significant discomfort requiring lCD repositioning was not observed, although one patient developed an erosion requiring surgical repair. Conclusions: Subpectoral implantation of the ICD gen erator is feasible and was well tolerated by all patients with an acce ptable complication rate (3.5). As the size of future generation ICDs is reduced, subpectoral implantation may become the preferred approach .