Abstract
We thank Dr Wilmshurst for his thoughtful letter in response to our study.' Dr Wilmshurst has pioneered the research on patent foramen ovate (PFO) in divers. We would like to point out a few important factors to consider.
We agree that divers with a high-grade shunt PFO should dive conservatively, if they do not undergo catheter-based dosure. We have published our experimental data on this topic previously, and it is also one of our conclusions in the present study.' The question that is yet to be answered is how conservative divers should be.
We agree that limiting maximum depth to 15 m while using common air decompression algorithms is probably very safe, but there are no data to support this depth restriction. Also, limiting the discussion to maximum depth only is an oversimplification.
Main factors to be considered are maximum depth, exposure time, ascent rate, safety stops, and number of repetitive dives. In the DIVE-PFO significantly differed between high-grade and closure groups, respectively.
Moreover, it is important to note that the definition of unprovoked decompres-sion sickness was strictly limited.