# Comparative efficacy and safety of nitinol vs. novel fully biodegradable occluders for transcatheter patent foramen ovale closure in migraine treatment: a retrospective cohort study

## TL;DR

This study compares two types of devices used to close heart defects in migraine patients and finds both are equally effective and safe.

## Contribution

The study provides the first comparative analysis of nitinol and biodegradable occluders for PFO closure in migraine treatment.

## Key findings

- Both nitinol and biodegradable occluders significantly reduced migraine severity with no significant difference in effectiveness.
- Biodegradable occluders showed progressive degradation over 12 months while maintaining closure efficacy.
- Both groups had high procedural success and low complication rates, with minimal residual shunting at 12 months.

## Abstract

Transcatheter closure of patent foramen ovale (PFO) has shown potential therapeutic benefits for clinical symptoms in selected patients with migraine. Nevertheless, the comparative effectiveness and safety of traditional nitinol vs. fully biodegradable occluders remain to be fully elucidated and warrant further investigation.

This retrospective cohort study included 158 migraine patients with a confirmed patent foramen ovale (PFO) and a grade II–III right-to-left shunt (RLS) as determined by contrast-enhanced transthoracic echocardiography (cTTE), who underwent transcatheter PFO closure at Shanghai East Hospital, Tongji University, between October 2023 and January 2024. Based on the occluder type, patients were categorized into a nitinol group (n = 77) or a biodegradable group (n = 81). Clinical baseline characteristics, echocardiographic parameters, procedural data, safety outcomes, residual right-to-left shunt (RLS) grades, and migraine severity assessed using the Migraine Disability Assessment Scale (MIDAS) were compared between groups. The primary outcome was migraine relief (≥50% reduction in MIDAS score) following the procedure. Secondary outcomes included the incidence of safety-related events and the rate of residual right-to-left shunt.

Both the nitinol group and biodegradable groups showed significant reductions in MIDAS scores post-procedure with no significant difference in migraine relief between groups (P = 0.644, Kaplan-Meier analysis). Both occluders showed a high procedural success rate (100%) and similar safety profiles, with low rates of perioperative complications. The biodegradable occluder exhibited progressive degradation, with a significant reduction in size by 12 months, while maintaining closure efficacy. Residual right-to-left shunting was minimal in both groups, with RLS grades 0 and 1 observed in 82.35% of patients in the nitinol group and 78.87% in the bioabsorbable group at the 12-month follow-up.

Both biodegradable and nitinol PFO occluders were equally effective in alleviating migraine symptoms, with excellent procedural success and safety profiles. The biodegradable occluder demonstrated effective closure and gradual degradation, offering a promising alternative to nitinol occluders, especially for patients concerned about long-term foreign body implantation. These findings support the clinical utility of both occluder types in PFO-related migraine treatment, with individualized device selection based on patient preferences and clinical factors.