Outcome After Surgery
- 90% good outcome, 5% mortality rate: In children with grades I-III Spetzler-Martin AVMs treated by resection, good recovery was achieved in 90% and deaths occurred at a rate of 5%.
- Radiographic obliteration rates were 89%(43)
- 0–12% morbidity resecting Spetzler-Martin grade I or II: Although class I or II data are lacking, the combined class III data strongly support resection as a primary treatment for patients with Spetzler-Martin grade I or II AVM. The low postoperative morbidity in these low-grade lesions (ranging from 0–12%), along with a high rate of complete obliteration (up to 100%), suggests that delayed control, inherent to radiosurgery, might not be warranted (39, 41–43).
Outcome After Radiation Therapy
- 80% obliteration rate: For comparison, a similar group of patients treated with radiosurgery alone had a reported 80% efficacy of lesion obliteration at 36 months, with 4 of 53 patients having recurrent hemorrhage after treatment (46).
- 4.3% rehemorrhage, 35% obliteration first 3 years children: One large pediatric AVM study included 40 patients and confirmed radiographic obliteration of the AVM nidus in 35% of them (47). The cumulative posttreatment hemorrhage rate was 3.2% per patient per year in the first year and 4.3% per patient per year over the first 3 years (47). These rates of obliteration, which are notably lower than those reported in the adult population, were potentially complicated by a slightly larger than average size of treated AVMs in the study group. In contrast, when a group of 53 children was stratified by AVM size (<3 cm3, 3–10 cm3 and >10 cm3), in the smallest and middle groups obliteration rates of 80% and 64.7%, respectively, were reported (46).
- Used small, deep lesions: Although class I and II data are lacking, the aggregate class III data strongly support the use of radiosurgery in the treatment of small (<3 cm diameter), deep-seated lesions in eloquent cortex. For Spetzler-Martin grade I and most grade II lesions, open resection is generally recommended over radiosurgery, unless there are specific considerations that make the patient unsuitable for resection. Radiosurgery should be used only for larger lesions (grade II-V), if the objective is complete obliteration of the AVM (48).
Outcome after Multimodality Therapy
- Neurointerventionalists, radiation oncologists, and neurosurgeons: Multimodality therapy of AVM has been advocated by several investigators(39, 41, 49, 50). Neurointerventionalists, radiation oncologists, and neurosurgeons work together to determine the best strategy for a particular patient. Using a multimodality approach, angiographic obliteration rates of 92.9% have been reported. In carefully selected patients treated with resection alone, a cure rate of 100% has been achieved (39).
- 58% obliteration in one report: The efficacy of multimodality treatment of large, complex lesions is supported by a group of 53 children at a 3-year follow-up. In these children a 58% cure rate was achieved for AVMs >6 cm in diameter (51).
In summary, the high likelihood of obliteration, coupled with low complication rates, make a convincing argument in favor of multimodality treatment of pediatric AVMs. Although no class I or II data directly support this recommendation, the class III data are compelling, and there is wisdom in pooling the skills of the concerned specialists.