If you follow my Instagram, aka "All Things Avery", you might remember that a few weeks ago we heard the results of Avery's recent sleep study and CT scan. The sleep study showed that Avery has been suffering from hypercapnia, or carbon dioxide retention from severe central sleep apnea. Prior to her acute episode of hydrocephalus/shunt malfunction back in September, Avery had never been on oxygen other than during operations. After she recovered from her ICP induced coma and seizures, her apnea persisted and we've had her on oxygen during her sleep since then. The sleep study showed that while the flow of oxygen keeps her O2 levels in a reasonable range, her carbon dioxide levels slowly rise throughout the night as her brain fails to send the message to EXHALE. We were advised to start her on a ventilator during sleep to preserve any brain function she has and keep her from essentially poisoning herself every night.
We also discovered that Avery's right coronal suture has "refused", her lamboids sutures had been fused since birth and her Chiari 1 malformation was worsening.
Traditionally, a Chiari 1 malformation involves the herniation of the cerebellar tonsils to some degree (3mm-5mm) and is usually asymptomatic. Avery's Chiari was initially classified as a level 1, but her recent CT scan was read as a "Chiari 2" (seen almost exclusively in the spina bifida community) malformation because her herniation now includes her cerebellar tonsils and a portion of her cerebellum, brain stem and 4th ventricle. The lack of room in her skull is forcing her brain down through her foramen magnum, into her spinal column and most likely causing her central sleep apnea along with a plethora of other symptoms.
So, HUGE DEAL.
Today we met with her neurosurgeon who advised that we operate on her Chiari malformation ASAP (like, this Wednesday, the 17th- his soonest available surgery time). The decompression surgery is very dangerous, even though we've decided on the least invasive version which would only include an incision down the back of her head and the removal of some of the bone from her C1 and C2 vertebrae ("suboccipital craniectomy" and "cervical laminectomy" if you're nerd who likes to research-like me 😊). Often a neurosurgeon will also perform a duraplasty to create additional space, but there's a good chance that Avery would bleed out on the operating table, so we've decided to skip that step and simply repeat the bony decompression (which is life-threatening enough for Avery because of how tight the back of her skull is) if symptoms reappear postoperatively.
Once Avery has healed from the decompression surgery, we will tackle a full CVR/FOA again, but with the addition of remove the occipital portion of her skull this time- essentially removing and remodeling her ENTIRE skull (as opposed to the CVR/FOA she had last year that simply involved release of both coronal sutures and her left orbit). Again, we will face the bleeding risk and possible termination mid-surgery, but there's an urgency to do these operations sooner than later as Avery has simply run out of room for her brain to continue growing.
Because Avery's Chiari malformation is in such bad shape, our surgeon has proposed lots of safety techniques that he doesn't normally employ (like nerve monitoring, etc) to try to lessen the probability that she will be paralyzed or unable to swallow, or... other stuff. 😑 We're sad that she will need so many invasive procedures in the next few months, but excited to have the process moving along quickly now and confident that we will have a good outcome.
Feel free to say a little prayer for us on Wednesday morning! Once these next two (or three) surgeries are complete, it's very likely Avery that won't ever need another skull surgery, or at least not for a long time. THAT is something to be excited about!