A PFO is present in 79% of divers with skin decompression sickness/illness (DCS/DCI).
This statistic was presented by Cardiologist Dr Peter Wilmhurst at the South Pacific Underwater Medicine Society (SPUMS) and summarised in this blog on the Diver Alert Network (DAN).
To read the full article click here
In another article on the DAN website the author discusses the interesting findings that skin mottling after diving may be the result of brain lesions caused by gas bubbles.
So it appears that skin bends should be taken seriously and that screening for a PFO needs to be seriously considered.
Here’s part of the quote (click here for the original article)
In a recently published paper, Kemper and colleagues1 present a novel hypothesis that links skin changes to overt or subclinical brain changes caused by cerebral arterial gas embolism (AGE). The research team from the Netherlands experimentally studied AGE in anesthetized pigs, with a focus on the effects of AGE on brain functions.2 However, they noticed that within minutes of injecting gas bubbles into cerebral circulation, a mottling appeared on the animal’s skin that resembled marbled skin characteristic of DCS in humans. They hypothesized that the brain injury resulting from the injection of gas bubbles led to a release of neuropeptides by sensory nerves in the skin, which initiated an inflammatory response and the appearance of skin mottling.
DAN injury data analysis as presented in various editions of the DAN Annual Report indicate that at least 20 percent of divers with skin DCS also have neurological symptoms that they may not be aware of but were discovered at a clinical examination. The hypothesis presented here suggests strengthening the current recommendations so that divers with skin mottling after a dive should receive a neurological evaluation. Even more, the repeated episodes of skin changes, while in itself may seem innocuous, should be taken seriously as a possible indicator of subclinical brain injury, and the diver’s diving practice should be reviewed and safety measures elevated.
Here is a post from the Diver Alert Network (DAN) discussing when to screen for a PFO in divers.
The following flowchart is for divers that have had a documented Decompression Illness (DCI) event.
For the full article and for other interesting information on diving and decompression illness click the link below.
Results of the 10 year extended follow up for the RESPECT trial were released in San Francisco in October 2015. The trial is the largest randomised PFO (Patent Foramen Ovale) trial in history with the longest follow up now reaching 10 years (5 yr mean), involving 980 patients to evaluate secondary stroke prevention.
The study looked at patients (18-60 years of age) with a hole in the heart (PFO) who had a stroke. Patients were assigned to medical therapy (blood thinners) or PFO closure via keyhole surgery with Amplatz PFO Occluder.
The study showed that closing the hole in the heart was safe and resulted in a 70% reduction in reduction of unexplained strokes. This research confirms the long held beliefs that PFO closure for young stroke is both safe and effective against preventing further stroke events.
For a more detailed analysis of the RESPECT trial please click here
RESPECT – Stroke and PFO Trial 10 yr results released
Results of the 10 year extended follow up for the RESPECT trial were released in San Francisco in October 2015. The trial is the largest randomised PFO trial in history with the longest follow up now reaching 10 years (5 yr mean), involving 980 patients to evaluate secondary stroke prevention.
What patients were involved?
- Patients with a PFO who have a cryptogenic stroke (stroke of unknown cause) in the last 270 days.
- Patients were randomised in to receiving the Amplatzer PFO Occluder (n=499) or receiving structured medical management (n=481)
Who was excluded?
- Patients aged <18 years or >60 years
- Patients with identified stroke cause
- Patients who were unable to discontinue anticoagulants (PFO closure patients had to cease Aspirin and other anticoagulants after 3 months)
Compared to the medical management at 10 year follow up (5 year mean) there was a:
- 75% relative risk reduction in patients with significant PFO’s or atrial septal aneurysm (p=0.007)
- 70% relative risk reduction in patients having PFO closure (p=0.004)
- 52% relative risk reduction for all causes of stroke (p=0.035)
- The procedure is safe with no major procedural complications
- Major vascular complication (0.9%), device explant (0.4%)
11% of patients assigned to the medical management arm left the trial due to having off-label PFO closure. This means stroke patients actively sort PFO closure elsewhere when they discovered they did not get the PFO closure procedure.
- Safe and highly effective procedure for stroke prevention in young patients with large PFO
- Stroke and recurrent stroke is a life long accumulative risk. Published rates of stroke in patients with untreated PFO range between 1-2% per year.
RESPECT – Stroke Comparing PFO Closure to Established Current Standard of Care Treatment
RESPECT Efficacy Summary
70% risk reduction Cryptogenic Stroke
75% less Stroke PFO closure
Stroke and other sources