Treatment of Unruptured Vertebral Artery Dissecting Aneurysms

A Juvenile Case of Bow Hunter's Syndrome Caused by Atlantoaxial Dislocation with Vertebral Artery Dissecting Aneurysm

BACKGROUND

Bow hunter's syndrome (BHS) is caused by posterior circulation insufficiency that results from the occlusion or compression of the vertebral artery (VA) during neck rotation. Owing to its rarity, there is no guideline to support the decision of selecting a conservative or a surgical approach. Management of BHS is dependent on each patient.

CASE DESCRIPTION

A 13-year-old girl presented with transient visual disturbance, hypoesthesia, and paralysis of the left side of the body. Magnetic resonance imaging revealed an acute cerebral infarction in the right thalamus, and magnetic resonance angiography demonstrated occlusion of the right posterior cerebral artery and dilation of V3 of the left VA. Digital subtraction angiography revealed a left VA dissecting aneurysm at V3 and left VA occlusion at the level of C1-C2 during neck rotation to the right. A dynamic x-ray suggested atlantoaxial joint instability, and three-dimensional computed tomography revealed aplasia of C1 lamina and atlantoaxial rotatory dislocation. BHS with left VA dissecting aneurysm caused by atlantoaxial rotatory dislocation was diagnosed. We performed C1-C2 posterior fusion by the Goel-Harms technique. Stroke did not recur, and computed tomography angiography obtained 8 months postoperatively demonstrated a decrease in the dissecting aneurysm.

CONCLUSIONS

To our knowledge, this is the first case of BHS with VA dissecting aneurysm and aplasia of C1 lamina. Based on this case, we suggest that C1-C2 posterior fusion is effective for BHS with VA dissecting aneurysm.

Surgical treatment of intracranial VA dissecting aneurysm

OBJECT

Intracranial VA dissections are reported to cause headache, brain stem infarction, and SAH with an associated high morbidity and mortality. We aimed to clarify both the clinical characteristics and effectual treatment of intracranial VA dissections, and to present a retrospective analysis of our experience in the treatment.

MATERIAL AND METHOD

Between 1995 and 2007 we experienced 62 VA dissections in our institution. Fourteen of 62 (23%) cases of VA dissections were associated with aneurysm, and received surgical treatment. Five of fourteen cases presented with SAH, 8/14 cases with ischemia, 1/14 cases with headache.

RESULTS

In the hemorrhagic group, internal trapping of aneurysm (ITA) was successfully performed in four cases. In one case, bypass surgery was followed by ITA, while one case with treatment-related complication was observed. But Glasgow Outcome Scale (GOS) of almost all cases was severe; 2/5 cases showed good recovery (GR), and 3/5 cases had severe disability. In the non-hemorrhagic group, proximal clipping or trapping was performed in 4/9 cases. Bypass surgery followed by proximal clipping or trapping was performed in 2/9 cases, and ITA in 1/9 case. One case showed treatment-related complication. GOS was GR in all cases.

CONCLUSION

Outcome in the hemorrhagic group was more severe as compared to the non-hemorrhagic group. The surgical strategy should be planned according to the location of the aneurysm and the origin of PICA.