AHA Coding Clinic® for ICD-10-CM and ICD-10-PCS - 2025 Issue 2; Ask the Editor
Encephalomyosynangiosis
A 9-year-old patient with Moyamoya disease was admitted for surgical treatment. The patient previously underwent a right extracranial to intracranial revascularization procedure using temporalis muscle and now presents for indirect revascularization of the left hemisphere. The left parietal superficial temporal artery was found to be extremely small and short, making it unsuitable for an indirect bypass. Therefore, a portion of the left temporalis muscle was harvested as a vascularized pedicled flap and used for indirect vascularization.Burr holes were created, and craniotomy bone flap was removed from the left frontotemporal region. An operating microscope was used to assist in opening the thickened arachnoid to allow ingrowth of new vessels from the muscle graft. The temporalis muscle with overlying fascia was sutured to the edges of the dura after placing it in intimate contact with the pial surface of the brain. The portion of the exposed brain was closed using a small piece of onlay dural graft superior to the muscle graft. The inner table of the bone was drilled to accommodate the bulk of muscle graft and the inferior portion of bone was trimmed to not compromise the pedicled vascularized muscle as it entered the subosseous space. The bone flap was then placed back onto the skull using a titanium plating system.What is the appropriate ICD-10-PCS root operation for indirect revascularization using the temporalis muscle (encephalomyosynangiosis)? ...
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Article Overview
This premium article covers a pediatric neurosurgical revascularization case for Moyamoya disease and explains the operative approach used when direct vessel options were not suitable. It is intended for coders, CDI teams, and neurosurgery professionals who need to understand the procedure context, anatomy, and documentation details associated with indirect revascularization techniques.
Why This Topic Matters
Accurate understanding of this procedure supports correct surgical coding and clinical documentation review for complex cerebrovascular cases, especially when the operative note uses specialized terminology tied to indirect revascularization.
What You Will Learn
- The clinical context for a Moyamoya disease revascularization case
- How an indirect cerebral revascularization approach is described in operative documentation
- The anatomy and surgical steps referenced in the procedure narrative
- Why detailed operative language matters for coding and documentation review
Who Should Read This
- Medical coders
- Clinical documentation integrity specialists
- Neurosurgery staff
- Health information management professionals
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