Spinal juvenile (Type III) extradural-intradural arteriovenous malformations

Spinal extradural-intradural AVMs

 J Neurosurg Spine 20:452–458, 2014

Owing to their rarity, demographics, natural history, and treatment, results for spinal juvenile (Type III) extradural-intradural arteriovenous malformations (AVMs) are frequently only provided in case report format.

Methods. A pooled analysis was performed utilizing the PubMed database through April 2013. Individualized patient data were extracted to elucidate demographics, hemorrhage risk, and treatment result information.

Results. Twenty-nine studies describing 51 patients were included. The mean age at presentation was 15.0 ± 10.5 years with a slight male predilection (63%, 1.7:1 sex ratio). Presentation modality included progressive deficits in 35%, hemorrhage in 31%, acute deficits not attributed to hemorrhage in 22%, and asymptomatic/incidental in 12% of patients. The annual hemorrhage rate was 2.1%; statistically significant risk factors for hemorrhage included presentation age (HR 0.39 [95% CI 0.18–0.87]) and associated aneurysms (HR 8.74 [95% CI 1.76–43.31]). Seventy-seven percent of patients underwent treatment; after a mean follow-up of 2.6 ± 3.2 years, 73% were improved, 10% were the same, and 17% were worse neurologically. Of 25 cases with described angiographic results, 8 lesions were obliterated (32%). Of these 25 patients, 8 had AVMs with associated aneurysms, and the aneurysm was obliterated in all 8 patients. Over the course of 57.9 patient-years of follow-up, including 55.3 patient-years for partially treated AVMs, no hemorrhages were described, reflecting a trend toward protection from hemorrhage after treatment (p = 0.12, likelihood ratio test).

Conclusions. Spinal juvenile (Type III) extradural-intradural AVMs commonly present symptomatically. Associated arterial aneurysms increase their hemorrhage risk, and protection from hemorrhage may be achieved from partial obliteration of these lesions, particularly if targeted toward associated aneurysms.

Spinal Glomus (Type II) Arteriovenous Malformations

Spinal Glomus (Type II) AVM

Neurosurgery 72:25–32, 2013

The natural history and treatment results for spinal glomus (type II) arteriovenous malformations (AVMs) remain relatively obscure.

OBJECTIVE: To calculate spinal glomus (type II) AVM hemorrhages rates and amalgamate results of intervention.

METHODS: We performed a pooled analysis via the PubMed database through May 2012, including studies with at least 3 cases. Data on individual patients were extracted and analyzed using a Cox proportional hazards regression model to obtain hazard ratios for hemorrhage risk factors.

RESULTS: The annual hemorrhage rate before treatment was 4% (95% confidence interval [confidence interval]: 3%-6%), increasing to 10% (95% CI: 7%-16%) for AVMs with previous hemorrhage. The hazard ratio for hemorrhage after hemorrhagic presentation was 2.25 (95% CI: 0.71-7.07), increasing to 13.0 within the first 10 years (95% CI: 1.44-118). The overall rates of complete obliteration were 78% (95% CI: 72%-83%) for surgery and 33% (95% CI: 24%-43%) for endovascular treatment. Long-term clinical worsening occurred in 12% of patients after surgical treatment (95% CI: 8%-16%) and in 13% after endovascular treatment (95% CI: 7%-21%). No hemorrhages occurred after complete obliteration. After partial surgical treatment, the annual hemorrhage rate was 3% (95% CI: 1%-6%); no hemorrhages were reported over 196 patient-years after partial endovascular treatment.

CONCLUSION: Spinal glomus (type II) AVMs with previous hemorrhage, particularly within 10 years, demonstrated a greater risk of hemorrhage. Complete obliteration and even partial endovascular treatment significantly decreased their hemorrhage rate.

KEY WORDS: