In vitro analysis of polymer candidates for the development of absorbable vascular filters

Abstract

Purpose: To test absorbable materials as a prelude to development of an absorbable vena cava filter for the prevention of pulmonary embolism (PE).

Materials and methods: Three absorbing polymer candidates, poliglecaprone (Monocryl; sizes 4-0 and 1), polyglactin (Vicryl; sizes 4-0 and 1), and polydioxanone (PDSII; sizes 4-0, 2-0, 0, and 1), were fabricated into vascular filters and evaluated in an engineered closed circulation system that replicated human physiologic characteristics. Material performance was determined over a period of 10 weeks via weekly tensile testing, yielding stress-versus-strain parameters. Control samples of the same absorbable polymers were also tested in a static buffer.

Results: PDSII (size 2-0) retained 69% strength in circulation versus 86% in control at 6 weeks (P < .0001) and 11% strength in circulation versus 51% in control at 10 weeks (P < .001). It was fully absorbed in circulation by 22 weeks. In contrast, Monocryl and Vicryl absorbed much faster, with Monocryl possessing 6% strength at 2 weeks in circulation and Vicryl reaching 0% strength at 4 weeks.

Conclusions: Polydioxanone appears to be a strong candidate for novel absorbable vascular filters for PE prevention, with sufficient strength retention to catch emboli for at least 6 weeks and sequentially absorb via hydrolysis into CO(2) and H(2)O within 22 weeks.