Can I go scuba diving with a ventricular shunt?

Your question raises many issues. While you asked specifically about diving with a ventricular shunt, there are additional considerations for someone with Spina Bifida.

The quick answer to your question is that the limited evidence suggests that someone with a ventricular shunt that does not drain into the blood stream can dive safely up to four atmospheres of pressure. This means that those who do not have a shunt that goes to the atrium (a ventriculoatrial or VA shunt) is most likely safe to dive down to 100 feet. This is based on research using decompression tanks (hyperbaric chambers) which showed that the shunts worked normally up to this pressure. The specialists believe that the shunt will drain normally because the brain/ventricles and the abdomen will be equally affected by the increased environmental pressure of the deeper water.

Now for more of the special considerations:

1. Some diving agencies allow for shunts only as long as the rest of the neurologic exam is normal. Others recognize the lifelong changes of conditions such as Spina Bifida and allow divers to be certified.
   
   
2. Shunts that are old or are no longer believed to be working may not equally respond to the pressure changes and are not known to be safe for diving.
   
   
3. Shunts draining a syrinx (spinal cord cyst) have not been tested. The spinal cord is not as capable of releasing nitrogen as the brain and may be more susceptible to decompression effects on the spinal blood vessels.
   
   
4. Shunts to the atrium are affected by the blood stream which may get nitrogen bubbles when surfacing during a dive. These may adversely affect the shunt and are not allowed by most diving certification agencies.
   
   
5. Individuals with seizure disorders are not allowed to dive. Some certifying agencies allow for divers who have been seizure free without medication for five years.
   
   

In addition to the shunt, potential divers with Spina Bifida also need to consider:

1. Thermal regulation issues – Diving in cold water or at deeper levels of warm water will promote vasoconstriction of the bodies blood vessels, meaning blood will be diverted from the skin to the body's core organs. This can adversely affect the limbs that do not have the sensation to recognize the cold temperatures. Thus, warm water diving and using wet suits are advised.
   
   
2. Musculoskeletal strength, mass, and sensation – Low muscle mass in the paralyzed limbs can affect buoyancy and may require weighted belts to help keep the diver submerged. Low bone density in the affected limbs may result in fractures if diving off the side of boats without accessible platforms. Limbs are subject to scrapes, cuts, and burns from underwater coral or plants. Wetsuits can protect the skin from these noxious agents. Another consideration is wetsuits that fit improperly as a result of decreased limb bulk may not adequately protect against the cold water.
   
   
3. Effects of bowel and bladder conduits and reconstruction – Bowel or bladder conduits, including Mitrofanoff and cecostomy continence ostomies, will allow water to back-flow into the bowel or bladder at depths as little as 5 feet below the surface. Therefore, the bowel or bladder can fill quickly, a particular concern for an augmented bladder which may rupture. Therefore, those with conduits are not advised to dive but may safely snorkel at the surface.
   
   
4. Latex precautions – Some diving equipment may contain latex, including the snorkel you breathe through. Check with the equipment companies first.
   
   
5. Fitness issues – Most SCUBA divers propel themselves with their arms and legs, with most of the force generated by finned lower extremities. Propelling by arms alone generally requires more energy and oxygen use, which can affect how fast the diver uses up the air in the SCUBA tanks and how quickly the diver becomes fatigued.
   
   

As always, individuals living with Spina Bifida are encouraged to participate in any and all activities that interest them. Because diving has unique safety issues due to the need for a specialized breathing apparatus and the special considerations of the increased atmospheric pressure from swimming underwater, one needs to be aware of all of the issues to remain safe for themselves and their diving partners.

There is a certification process available from the Handicapped SCUBA Association. For more information, please visit www.hsascuba.com/. The Health Guide for Adults Living with Spina Bifida is a good overview of the medical issues surrounding Spina Bifida.

References used in preparation of this Question of the Month include:

Cheng JF, Diamond M. SCUBA diving for individuals with disabilities. Am J Phys Med Rehabil. 2005;84:369-375.

For more information on the genetics and factors associated with Spina Bifida, please visit the Spina Bifida Association fact sheet.

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