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.