Background: Patent Foramen Ovale (PFO) is a common abnormality that affects between 25% and 34% of the general population. For most people, it is a benign finding; however, in some, the PFO can be wider, allowing a paradoxical embolus to transit from the venous to the arterial circulation, which is associated with cryptogenic stroke, migraine, and decompression sickness (DCS).
Methods: We performed a systematic review using the PRISMA protocol to identify articles describing epidemiological characteristics, prevalence, and presentation of ischemic stroke among scuba divers and the role of PFO closure as secondary prevention using the PubMed search engine. we identified English, full text, case reports, and observational studies mentioning the details and outcomes of PFO closure, from Jan 1, 2010, to the present by utilizing the following keywords or MeSH terms: “scuba divers”[Title/Abstract] AND (“pfo closure”[Title/Abstract] OR “surgical patent foramen ovale closure”[Title/Abstract] OR “patent foramen ovale”[Title/Abstract])) AND ((y_10[Filter]) AND (fft[Filter])).
Results: We identified 12 studies out of 28 with patients with PFO closure and a history of ischemic stroke among scuba divers. The incidence of ischemic stroke ranged from 0.01% to 0.095%. The mean age was 38 years (range: 34 – 42). We found no gender differences. However, among men, the risk of having a stroke was 4.5 times higher in PFO divers than in non-PFO divers. (RR: 4.5%, [95% CI, 1.2 to 18.0]; P = 0.03). The most commonly identified risk factor was smoking and common presenting symptoms were limb tingling, confusion, headache, and loss of consciousness. We also discovered a shorter latency period to have a stroke in non-PFO patients compared to PFO patients (70 min vs. 155 min), and the average depth of diving in stroke patients was 41 feet. We also noticed the beneficial effect of PFO closure over medical therapy among stroke patients. (HR: 0.55, [95% CI: 0.31–0.99]; p=0.046)
Conclusions: We found that there is enough evidence that PFO closure prevents recurrent strokes in divers and helps them maintain their diving activities. Still, there aren’t enough studies that can be used to formulate appropriate guidelines for screening the divers for PFOs and the use of percutaneous devices for PFO closure.