Comparison of single-coil lead versus dual-coil lead of implantable cardioverter defibrillator on lead-related venous complications in a canine model.

PURPOSE: Dual- coil lead (DCL) of implantable cardioverter defibrillator (ICD) is preferred clinically in patients. However, it is related to higher risk of venous stenosis and thrombosis. The present study was done to compare the fibrosis and extraction of the leads between the single-coil lead (SCL) and DCL in animal models.

METHODS: This was a chronic animal study with a follow-up duration of 6 months. Twenty mongrel dogs were randomly divided into DCL group or SCL group. Venography was performed before the sacrifice to evaluate the venous stenosis in vivo. The maximum pulling-out tension of the ICD lead was measured by a tensometer. Hematoxylin-eosin stain and toluidine blue O stain were applied to show the pathological changes of the superior vena cava (SVC) to evaluate the fibrosis and the thickness of the SVC adjacent to the leads.

RESULTS: The DCL group showed higher incidence of venous stenosis (OR = 31.5; 95% CI, 2.35-422.3; p = 0.005). It revealed increased tension to extract the leads in the DCL group (5.96 ± 1.86 vs. 3.68 ± 1.46 N, p = 0.027). The difference of venous wall thickness of SVC was 4.3 ± 0.3 fold-changes between two groups (p = 0.007). Moreover, the degree of venous wall fibrosis in DCL group was more serious than that it in SCL group (3.61 ± 1.26 vs. 1.08 ± 1.35 mm2 , p = 0.015).

CONCLUSION: The DCL was proved to increase thrombosis, fibrosis, and stenosis in the SVC. Likewise, the DCL was mechanically harder to be extracted than the SCL. Our study showed that lead-related complications of the DCLs were higher than those of the SCLs regardless of the equal defibrillation thresholds between them. Results of the present study would help to choose the proper lead which could be removed.