Anatomical classification of patent foramen ovale before percutaneous closure

Abstract

Introduction

Anatomical characteristics of patent foramen ovale (PFO) vary a lot, potentially impacting the embolic risk, selection of the device and the final sealing results of the closure procedure.

Objective

To categorize the different PFO anatomies and evaluate the consequence on the type of device used and the incidence of residual shunt.

Method

In total, 624 consecutive patients who underwent PFO percutaneous closure with transoesophageal echocardiography (TEE) guidance in our center in France were retrospectively reviewed. Four types of PFO were identified, with two subcategories (Figure 1).

For each category, the number and types of implanted devices were collected, and the presence of residual shunt was evaluated 6 months after the procedure.

Results

Our population had a median age of 51 [41-59] years and included 43.8% women. The type II PFO was the most frequently encountered, with 42% of the patients (Table 1).

A total of 93 (14.9%) patients presented multiple types concomitantly (mostly type II and III). PFO occluders were the most implanted devices overall, particularly with type I and IIa, while ASD occluders were more frequently used with types IV and IIb. Cribriform/Uni devices were more frequently used with type IV. Large devices were predominantly used with type III and IV, but scarcely employed with type I and II. Within type II anatomies, large devices were more frequently used with type IIb. At 6 months ultrasound evaluation, large right-to-left residual shunt was significantly more frequent with type IV anatomy. No significant differences were observed regarding clinical outcomes during follow-up.

Conclusion

Based on specific anatomical characteristics, four types of PFO may be identified, presenting with increasing procedural complexity, and requesting specific closure devices.