Patent Foramen Ovale
Conditions
Keywords
Patent foramen ovale, Catheter-based closure, Nitrogen bubbles, Decompression sickness
Brief summary
The aim of this study is to determine whether catheter-based closure of patent foramen ovale is effective in preventing paradoxical embolization of nitrogen bubbles after simulated dives.
Detailed description
The aim of this study is to determine whether catheter-based closure of patent foramen ovale (PFO) is effective in preventing paradoxical embolization of nitrogen bubbles after simulated dives. Ultrasonographic detection of venous and arterial nitrogen bubbles will be performed in divers after surfacing from simulated dives in hyperbaric chambers. Divers will be observed after two different dive profiles - Dive A (dive to 18 m for 80 min bottom time) and dive B (dive to 50 m for 20 min bottom time), both performed according to US Navy Air decompression procedure 1996. For both dives two groups will be compared: Divers with PFO and divers after previous catheter-based closure of PFO. The study will be observational. Sonographic detection of bubbles will be performed after simulated dives that are part of a training program of the divers. Two different dives, previously documented to generate significant amount of venous nitrogen bubbles, were chosen. The primary end-point will be a positive transcranial doppler test (defined as one or more bubbles detected either during native breathing or after Valsalva maneuver). Inclusion criteria are: 1) previously diagnosed PFO or a PFO that has been occluded by a catheter-based procedure, 2) signed informed consent Exclusion criteria: 1) another dive performed in the preceding 24 hours, 2) another previously diagnosed right-to-left shunt, 3) disagreement to be included in the study This study will be single-center.
Interventions
None listed
Sponsors
University Hospital, Motol
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
19 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. previously diagnosed PFO or a PFO that has been occluded by a catheter-based procedure 2. signed informed consent
Exclusion criteria
1. another dive performed in the preceding 24 hours 2. another previously diagnosed right-to-left shunt 3. disagreement to be included in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Arterial Nitrogen Bubbles After Surfacing | assesed within 1 hour after surfacing | Arterial gas bubbles are detected by transcranial doppler ultrasonography. Positive outcome is 1 or more bubbles detected. |
Countries
Czechia
Participant flow
Recruitment details
All participants were included consecutively in the Hyperbaric chamber of the Regional hospital Kladno, Kladno, Czech Republic and at Hyperbaric chamber Vyškov, Vyškov, Czech Republic, where they performed a training dive. Two dive profiles were performed (dive A and Dive B). The recruitment took part between 15/May/2013 and 15/June/2013.
Pre-assignment details
No participants were excluded from the study, all enrolled participants completed the study, no transition between groups occured.
Participants by arm
| Arm | Count |
|---|---|
| Closure Dive A Group Divers with a patent foramen ovale previously closed by a catheter-based procedure observed after Dive A. | 15 |
| Patent Foramen Ovale Dive A Group Divers with a previously diagnosed patent foramen ovale observed after dive A. | 19 |
| Closure Dive B Group Divers with a patent foramen ovale previously closed by a catheter-based procedure observed after Dive B. | 5 |
| Patent Foramen Ovale Dive B Group Divers with a previously diagnosed patent foramen ovale observed after dive B. | 8 |
| Total | 47 |
Baseline characteristics
| Characteristic | Patent Foramen Ovale Dive B Group | Total | Closure Dive A Group | Patent Foramen Ovale Dive A Group | Closure Dive B Group |
|---|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 8 Participants | 47 Participants | 15 Participants | 19 Participants | 5 Participants |
| Age Continuous | 33 years STANDARD_DEVIATION 4.8 | 35 years STANDARD_DEVIATION 8.6 | 41 years STANDARD_DEVIATION 8.5 | 33 years STANDARD_DEVIATION 7.6 | 33 years STANDARD_DEVIATION 12.1 |
| Body mass index | 25.2 kg/m2 STANDARD_DEVIATION 2.2 | 26.3 kg/m2 STANDARD_DEVIATION 3.9 | 27.3 kg/m2 STANDARD_DEVIATION 3.9 | 25.9 kg/m2 STANDARD_DEVIATION 4.2 | 28.3 kg/m2 STANDARD_DEVIATION 5.7 |
| history of decompression sickness | 3 participants | 31 participants | 14 participants | 10 participants | 4 participants |
| Number of decompression dives | 44 Dives STANDARD_DEVIATION 82 | 127 Dives STANDARD_DEVIATION 228 | 251 Dives STANDARD_DEVIATION 314 | 70 Dives STANDARD_DEVIATION 180 | 150 Dives STANDARD_DEVIATION 162 |
| Number of dives | 191 Dives STANDARD_DEVIATION 339 | 622 Dives STANDARD_DEVIATION 1238 | 1237 Dives STANDARD_DEVIATION 1762 | 412 Dives STANDARD_DEVIATION 984 | 998 Dives STANDARD_DEVIATION 1851 |
| Region of Enrollment Czech Republic | 8 participants | 47 participants | 15 participants | 19 participants | 5 participants |
| Sex: Female, Male Female | 0 Participants | 9 Participants | 3 Participants | 5 Participants | 1 Participants |
| Sex: Female, Male Male | 8 Participants | 38 Participants | 12 Participants | 14 Participants | 4 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 15 | 4 / 19 | 0 / 5 | 2 / 8 |
| serious Total, serious adverse events | 0 / 15 | 0 / 19 | 0 / 5 | 0 / 8 |
Outcome results
Primary
Arterial Nitrogen Bubbles After Surfacing
Arterial gas bubbles are detected by transcranial doppler ultrasonography. Positive outcome is 1 or more bubbles detected.
Time frame: assesed within 1 hour after surfacing
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Closure Dive A Group | Arterial Nitrogen Bubbles After Surfacing | 0 participants |
| Patent Foramen Ovale Dive A Group | Arterial Nitrogen Bubbles After Surfacing | 6 participants |
| Closure Dive B Group | Arterial Nitrogen Bubbles After Surfacing | 0 participants |
| Patent Foramen Ovale Dive B Group | Arterial Nitrogen Bubbles After Surfacing | 7 participants |
Comparison: null hypothesis: there is no difference in the occurence of arterial bubbles after simulated dive between closure and PFO groups.p-value: 0.02Fisher Exact
Comparison: null hypothesis: there is no difference in the occurence of arterial bubbles after simulated dive between closure and PFO groups.p-value: <0.01Fisher Exact