Generator pocket adhesions of cardiac leads: classification and correlation with transvenous lead extraction results

Abstract

Objectives: Pacemaker (PM) and implantable cardioverter defibrillator (ICD) leads become encapsulated intravascularly and in the generator pocket by fibrotic adhesions that accumulate over time. These adhesions are responsible for the difficulty and risk of lead extraction procedures. We developed a classification scheme for pocket adhesions, classified all of the patients in the cohort, and examined the relationship between pocket adhesions and the outcome of the procedure.

Methods: The classification of adhesions with respect to the intraoperative adhesion coverage was as followed: class 0 = adhesion free; class 1 ≤ 30% of adhesion coverage; class 2 = 30-60% of adhesion coverage; and class 3 ≥ 60% coverage. Patient data between December 2010 and March 2012 were collected. A total of 100 leads were extracted from 58 patients (1.7 ± 0.8 leads/patient); the mean lead implant duration was 78.5 ± 66.7 months, and the percentage of PM/ICD leads was 68% (n = 68)/32% (n = 32).

Results: Distribution of the leads among classes: 0 = 10; 1 = 17; 2 = 25; and 3 = 48. Average implant times (months) according to the adhesion classes: 0 = 1.2 ± 0.4; 1 = 19.8 ± 19.2; 2 = 79.3 ± 46.6; and 3 = 115.1 ± 106.0 (correlation-coefficient 0.71; P ≤ 0.05). Average numbers of extraction tools used according to the adhesions: 0 = none; 1 = 0.4 ± 0.7; 2 = 1.6 ± 1.0; and 3 = 2.3 ± 1.2 (correlation coefficient = 0.67; P ≤ 0.05). Complete removal was achieved in 100% of the patients in classes 0 and 1; 96% in class 2 (n = 24); and 75% in class 3 (n = 36) (P ≤ 0.05). Mortality = 0.

Conclusions: Extensive adhesions in the generator pocket predict the need for a higher number of extraction tools. High-grade pocket adhesions predict lower success rates with regard to complete lead extraction. Both findings suggest that the degree of pocket adhesions predicts the degree of intravascular adhesions.

Keywords: classification; defibrillation - ICD; lead extraction; pacing; surgery.