Management
The approach to management of AVMs is dependent on location, and they
are classified as either intracranial or extracranial. A cranial lesion
leads to the inclusion of neurosurgery to guide care. Otherwise, a
multidisciplinary approach to clinical decisions will help to promote
optimal outcomes through consideration of the risks and benefits of the
treatment options for both types of AVMs. Traditionally procedures such
as surgical endovascular resection, embolization using a chemical for
glue, coil placement, and radiation therapy are considered the primary
interventions for AVM management (75). Recently, several investigators
have reported an association with somatic KRAS mutations and AVMs (76).
These mutations lead to aberrant activation of the MAPK signaling
pathway. Several case reports describe radiologic response to inhibition
of this path with biologic agents, such as AKT inhibitors (76,77).
Therefore, medical therapies for AVMs may be new modalities for
treatment in the future and several studies are underway (78).
Following her initial visit, the patients headaches resolved. Therefore,
a non-urgent elective embolism with interventional radiology was
recommended in the next year. The parents were asked to monitor for
increased size or new symptoms. Approximately six months later, the
patient re-presented with cramping pain in the right supraclavicular
area and there was an increase in size of the AVM. A selective
embolization utilizing n-butyl cyanoacrylate (Onyx) was performed (79).
In addition, peri-procedural sirolimus was used in order to decrease
post-embolism collateralization (80,81). A cerebral angiogram was
performed to allow better visualization of the anatomic vasculature, and
revealed a malformation within the right upper thoracic and cervical
regions, with significant blood supply from the thyrocervical trunk and
common origin, ascending cervical, deep cervical and right occipital
arteries. She underwent 3 embolization procedures, every 2 weeks, and
had a good response. Her lesion became smaller both on clinical exam and
by MRI imaging. She was asymptomatic and followed every 6 months for a
year and then annually with both exam and MRI. She has been followed
post procedure for 5 years without recurrence or increase in AVM. Of
note, no genetic testing was performed due to lack of biopsy tissue
sampling.