Strategies to increase the INGEVITY lead strength during lead extraction procedures based on laboratory bench testing
Pierce J. Vatterott, Andrew De Kock, Eric Hammill, Robert K. Lewis
Abstract
BACKGROUND: The INGEVITY lead (Boston Scientific, St Paul, MN, USA) has excellent clinical performance. However, its single filar design results in decreased lead tensile strength and a possible challenging extraction. This study's goal is to evaluate techniques for extracting the INGEVITY lead. METHODS: Two- and three-dimensional models were created to simulate lead extraction from a right atrial appendage lead implant with a left subclavian approach and lead/fibrosis attachment sites. Standard and unique lead extraction preparation strategies were evaluated. Traction forces were measured from a superior approach alone or in combination with a femoral approach. RESULTS: For lead extraction via the superior approach, leaving the terminal on the lead was the only factor influencing maximum tolerated load (p-value = .0007). Scar attachment provided greater lead tensile strength by transferring traction loading forces to the polyurethane outer insulation but dependent on insulation integrity. The strongest extraction rail was seen with a simulated femoral snaring of a locking stylet within the INGEVITY lead. Deployed screw retraction was most successful by rotating a Philips LLD#2 stylet (Philips Healthcare, Amsterdam, Netherlands) within the lead. CONCLUSION: Results from in vitro simulations of INGEVITY lead extraction from an atrial location found the lead has low maximum tensile strength resulting in a poor extraction rail with common extraction tools and methods. However, the strength of the INGEVITY Lead extraction rail can be significantly increased by leaving the lead terminal intact and femoral snaring of the locking stylet within the lead. Such techniques may improve extraction of the INGEVITY lead.