Does persistent (patent) foramen ovale closure reduce the risk of recurrent decompression sickness in scuba divers?

Interatrial communication is associated with an increased risk of decompression sickness (DCS) in scuba diving. It has been proposed that there would be a decreased risk of DCS after closure of the interatrial communication, i.e., persistent (patent) foramen ovale (PFO). However, the clinical evidence supporting this is limited. Medical records were reviewed to identify Swedish scuba divers with a history of DCS and catheter closure of an interatrial communication. Thereafter, phone interviews were conducted with questions regarding diving and DCS. All Swedish divers who had had catheter-based PFO-closure because of DCS were followed up, assessing post-closure diving habits and recurrent DCS. Nine divers, all with a PFO, were included. Eight were diving post-closure. These divers had performed 6,835 dives (median 410, range 140-2,200) before closure, and 4,708 dives (median 413, range 11-2,000) after closure. Seven cases with mild and 10 with serious DCS symptoms were reported before the PFO closure. One diver with a small residual shunt suffered serious DCS post-closure; however, that dive was performed with a provocative diving profile. Divers with PFO and DCS continue to dive after PFO closure and this seems to be fairly safe. Our study suggests a conservative diving profile when there is a residual shunt after PFO closure, to prevent recurrent DCS events.