Hi, Complex Chiari malformation, also known as Type II Chiari malformation, is a condition in which a part of the brain called the cerebellar tonsils protrudes into the spinal canal. Decompression surgery is the standard treatment for Chiari malformation and involves removing a small portion of the bone at the back of the skull and upper neck to relieve pressure on the brain and spinal cord. While there is no cure for Chiari malformation, decompression surgery can alleviate symptoms and prevent further neurological damage. The surgery is generally considered safe and effective, with a success rate of 80-90%. However, as with any surgery, there are risks and potential complications, including infection, bleeding, and damage to surrounding structures. Your son needs to have a thorough evaluation by a neurosurgeon who is experienced in treating Chiari malformation to determine if surgery is appropriate for his specific condition. The decision to undergo surgery should be based on the severity of symptoms, the extent of the malformation, and the potential risks and benefits of surgery. To find a support group for persons who have had decompression surgery for Chiari malformation, you can search online for patient advocacy organizations such as the Chiari & Syringomyelia Foundation or the American Syringomyelia & Chiari Alliance Project. These organizations may have resources and information about support groups in your area or online. Your son s doctor may also be able to provide information or referrals to support groups. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician