Simultaneous insulation deterioration associated with side-by-side subclavian placement of two polyurethane leads.

During implantation of a bipolar dual chamber pacing system, two polyurethane leads were placed side-by-side through a single left subclavian vein puncture. The costoclavicular space was restrictive at the insertion site, and binding of the leads in this region made positioning difficult. Eleven months later, although pacemaker function remained normal, deterioration of both leads' insulation was noted on routine chest roentgenogram. Sixteen months after implantation, both leads failed. Insertion of polyurethane leads through a tight costoclavicular region should be avoided as subsequent mechanical stressing of the insulation may result in delayed lead failure.