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 the pectoral region, complications associated with the technique are being identified. To determine the incidence of lead complications in patients with transvenous defibrillator leads and ICDs implanted in the pectoral region, 132 unselected consecutive patients with transvenous defibrillator leads had ICDs implanted in the pectoral region. Three lead systems were used: (1) lead system 1 (45 patients) consisted of a transvenous pacing sensing lead and a superior vena cava coil with a submuscular patch used for defibrillation; (2) lead system 2 (36 patients) utilized a CPI Endotak lead system; and (3) lead system 3 (51 patients) utilized a Medtronic Transvene lead system. Patients were followed for 3-54 months (cumulative 2,269, mean 18 months). The average duration of follow-up with the three systems was 32, 12, and 11 months, respectively At 30 months follow-up, all three lead systems had a low incidence of complications. However, there was a 13% overall incidence (45% actuarial incidence) of erosion of the insulation of the pacing sensing lead of system 1 at 50 months of follow-up. All lead complications were seen in patients with ICDs whose weights were > 195 g and volumes > 115 cc. The erosion was probably a consequence of the pressure by the large ICD against the lead in the pectoral pocket. Follow-up with lead systems 2 and 3 is relatively short (average 12 months) but no lead erosions were seen. Pectoral implantation of ICDs with long transvenous leads and large generators is associated with a moderate risk of late complications in the form of insulation breaks caused by pressure of the generator against the leads. The use of less redundant leads coupled with smaller ICDs will probably eliminate this complication.