Fully biodegradable versus nitinol occluder devices for transcatheter patent foramen ovale closure: A systematic review

Abstract

Background: The optimal device platform for transcatheter patent foramen ovale (PFO) closure remains uncertain. Permanent nitinol occluders are widely used, but concerns persist regarding long-term foreign-body exposure and device-related complications. Fully biodegradable occluders have been developed to provide temporary septal support during endothelialization before gradual resorption, with the intended benefit accruing only after the device has resorbed.

Methods: We systematically searched Medline, PubMed, Embase, Scopus, Web of Science, the Cochrane Library, and trial registries through 17 February 2026. Eligible studies were randomized or comparative observational studies of patients aged 16 years or older undergoing PFO closure with biodegradable or bioresorbable versus nitinol or metallic occluders. Two reviewers independently screened studies and extracted data. Risk of bias was assessed using RoB 2 for randomized evidence and ROBINS-I for non-randomized evidence. Because of clinical and methodological heterogeneity, findings were synthesized narratively.

Results: Three comparative studies were included — one randomized trial and two retrospective cohorts — comprising 481 analyzed participants. Procedural success was high with both device types. Residual shunt generally decreased over time, with no clear advantage for either platform. Serious adverse events, device thrombosis, embolization or detachment, and atrial arrhythmias were uncommon, though event counts were small. Two of the three studies were migraine-specific cohorts, and the randomized trial enrolled a mixed-indication population in which treatment-resistant migraine was the most common single indication; the available evidence therefore reflects device-platform performance predominantly in migraine populations. No study followed participants substantially beyond the expected biodegradation window.

Conclusion: Current evidence suggests similar short- to mid-term performance of biodegradable and nitinol occluders, but certainty is low to very low, and no study yet assesses the post-resorption period in which any advantage of a biodegradable platform would be expected to emerge. Larger multicenter studies with standardized imaging, rhythm monitoring, and follow-up extending beyond biodegradation are needed. Because two of the three studies were migraine-specific and event counts were small, these findings should not be extrapolated to stroke-prevention populations, and the absence of observed between-device differences should not be interpreted as equivalence.