Tines made of degradable materials with decreasing removal forces: An option to facilitate passive-fixation leads extraction from the very beginning?

Abstract

Risks during transvenous lead extraction (TLE) are serious, especially for passive fixation (PFix) leads. We attempted to fabricate a PFix lead using degradable tines to facilitate lead removal. Dried polymer mixture with poly (d-lac tide-co-glycolicde acid) (PLGA)/Poly (l-lac tide-co-ε-caprolactone) (PLCL) were put into to a specially-made mold respectively to test the tine-making feasibility and the final formulation was determined as PLGA25-PLCL75 with mass ratio 25:75 of PLGA/PLCL. Dynamic mechanical analysis and X-ray Diffraction showed excellent physicochemical characterizations, and further tests demonstrated satisfying mechanical properties similar to traditional silicone tines. The PLGA25-PLCL75 also showed low cytotoxicity and appropriate biodegradability in vitro and in vivo. The PFix leads were tested to reassure the implantation feasibility before implantation via standard surgery operation procedure. Then the leads were implanted into dog’s endocardium. The animal study showed the degradable tines could accomplish fixation stability and were with less manual extraction forces comparing with traditional silicon fixation tines in 7-month’s observation time. Tines made of PLGA25-PLCL75 blends were almost degraded totally only few remnants observed under microscope comparing with intact silicon materials at the tine-myocardial interfaces. The PFix lead might revolutionize products because of the introduction of this degradable fixation tines that make easier removal.

Keywords

• Lead extraction
• Degradable fixation-tine
• PLGA
• PLCL