LATE COMPLICATIONS IN PATIENTS WITH PECTORAL DEFIBRILLATOR IMPLANTS WITH TRANSVENOUS DEFIBRILLATOR LEAD SYSTEMS - HIGH-INCIDENCE OF INSULATION BREAKDOWN

As the majority of ICDs with transvenous leads are now implanted in th e pectoral region, complications associated with the technique are bei ng identified. To determine the incidence of lead complications in pat ients with transvenous defibrillator leads and ICDs implanted in the p ectoral region, 132 unselected consecutive patients with transvenous d efibrillator leads had ICDs implanted in the pectoral region. Three le ad systems were used: (1) lead system 1 (45 patients) consisted of a t ransvenous pacing sensing lead and a superior vena cava coil with a su bmuscular patch used for defibrillation; (2) lead system 2 (36 patient s) utilized a CPI Endotak lead system; and (3) lead system 3 (51 patie nts) utilized a Medtronic Transvene lead system. Patients were followe d for 3-54 months (cumulative 2,269, mean 18 months). The average dura tion of follow-up with the three systems was 32, 12, and 11 months, re spectively At 30 months follow-up, all three lead systems had a low in cidence of complications. However, there was a 13% overall incidence ( 45% actuarial incidence) of erosion of the insulation of the pacing se nsing lead of system 1 at 50 months of follow-up. All lead complicatio ns were seen in patients with ICDs whose weights were > 195 g and volu mes > 115 cc. The erosion was probably a consequence of the pressure b y the large ICD against the lead in the pectoral pocket. Follow-up wit h lead systems 2 and 3 is relatively short (average 12 months) but no lead erosions were seen. Pectoral implantation of ICDs with long trans venous leads and large generators is associated with a moderate risk o f late complications in the form of insulation breaks caused by pressu re of the generator against the leads. The use of less redundant leads coupled with smaller ICDs will probably eliminate this complication.