Neurosurgery Coding Alert

Question: Encounter notes indicate that the surgeon performed craniotomy for a patient with a malformation due to type II Arnold-Chiari syndrome without spina bifida or hydrocephalus. They removed a portion of the occipital bone at the back of the skull to relieve pressure on the brain stem and spinal cord. The surgeon then expanded the dura by suturing a dural graft in place. How should I code this encounter?

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Answer: For this encounter, report 61343 (Craniectomy, suboccipital with cervical laminectomy for decompression of medulla and spinal cord, with or without dural graft (eg, Arnold- Chiari malformation)) for the craniotomy. Since the dural graft is mentioned in the 61343 descriptor, you shouldn’t submit an additional code for the graft placement. Also, append Q07.00 (Arnold-Chiari syndrome without spina bifida or hydrocephalus) appended to 61343 to represent the patient’s condition.

Arnold-Chiari alert: There are several diagnosis code options for Arnold-Chiari malformation, type II. In addition to Q07.00, you might have also chosen one of the following codes for a type II malformation:

• Q07.01 (Arnold-Chiari syndrome with spina bifida)
• Q07.02 (Arnold-Chiari syndrome with hydrocephalus)
• Q07.03 (Arnold-Chiari syndrome with spina bifida and hydrocephalus)

Arnold-Chiari alert 2: The Q07.- (Arnold-Chiari syndrome) codes are for type II Arnold-Chari malformations as well as type I malformations — even though there are differences in the conditions. According to Mayo Clinic, “type I Chiari malformation symptoms and signs can show up in infants, children, teens or adults. Type II Chiari malformation is associated with spina bifida and is present at birth.”

If however, the notes mention type III Arnold-Chari malformation, you’ll choose a code from the Q01.- (Encephalocele) set. When it’s indicated that the patient has a type IV malformation, you’ll choose a code from the Q04.8 (Other specified congenital malformations of brain) set.