Vertebrobasilar insufficiency. Part 1: Microsurgical treatment of extracranial vertebrobasilar disease

Superficial temporal and occipital artery bypass pedicles to superior, anterior inferior, and posterior inferior cerebellar arteries for vertebrobasilar insufficiency

Eighty-three patients underwent 85 intracranial to extracranial pedicle bypass anastomosis procedures to the posterior circulation. There were 15 patients with occipital artery (OA) to posterior inferior cerebellar artery (PICA) anastomosis, 20 patients with OA to anterior inferior cerebellar artery (AICA) anastomosis, and 50 patients with superficial temporal artery (STA) to superior cerebellar artery (SCA) anastomosis. All patients had transient ischemic attacks (TIA's) suggestive of vertebrobasilar ischemia. Twenty-seven patients had crescendo TIA's or stroke in evolution and were considered to be clinically unstable. All patients had severe bilateral distal vertebral artery or basilar artery disease. Twenty-two patients had bilateral vertebral artery occlusion and three had basilar artery occlusion. In this series, 69% had complete resolution of symptoms; the mortality rate was 8.4% and the morbidity rate 13.3%. Clinically stable patients did better than unstable patients. The STA-SCA anastomosis was well tolerated and technically less demanding than the OA-PICA or OA-AICA anastomosis procedures. Patients with symptomatic severe bilateral vertebral or basilar artery disease have a grave prognosis and the option of a surgical arterial pedicle revascularization procedure should be offered to them.

Vertebrobasilar insufficiency revealed by xenon-133 inhalation SPECT

A study of cerebral and cerebellar blood flow reactivity to acetazolamide by xenon-133-inhalation single photon emission computed tomography (133Xe SPECT) was carried out in a patient with bouts of transient basilar ischemia, whose neurological examination, computed tomographic scan, and auditory evoked potentials were normal. Though the patient was symptom-free at the time of the study, 133Xe SPECT demonstrated vertebrobasilar insufficiency by showing an impaired vasodilatory response in both the occipital lobes and the right cerebellar hemisphere. Three weeks later, the patient suffered an extensive stroke in these same areas. We therefore suggest that this method could be of great value in the assessment of vertebrobasilar insufficiency.

Complications of intracranial bypass for vertebrobasilar insufficiency

The authors' initial experience with intracranial revascularization of vertebrobasilar insufficiency, reported previously, fortunately yielded reasonably good results with high patency rates but in some cases there were significant, albeit temporary, complications. Since that time, major brain-stem strokes have occurred in two patients following superficial temporal to superior cerebellar artery bypass procedures. This occurrence has caused the authors to reassess their experience with this procedure and review the published literature with regard to complications. This review and the results of the international bypass study on anterior circulation ischemia suggest that a very cautious and conservative approach should be taken prior to considering intracranial bypass to the superior cerebellar or posterior cerebral artery.

A case of cerebello-pontine angle infarction found by vertebral angiography

A patient was admitted complaining of sudden vertigo. Otoneurological examinations, electronystagmography (ENG), and vertebral angiography (VAG) showed constriction of vertebral artery and anterior inferior cerebellar artery, and basilar artery obstruction. Based on these findings, we diagnosed the case as posterior cranial fossa infarction. Computed tomography (CT) and magnetic resonance imaging (MRI) findings were negative. The authors conclude that VAG should be performed in certain cases of vertigo thought to be of central nervous origin when CT and MRI findings are both negative.

Vertebrobasilar insufficiency. Part 2. Microsurgical treatment of intracranial vertebrobasilar disease

Posterior circulation transient ischemic attacks have an associated risk of subsequent infarction of approximately 5% per year. Intracranial vertebrobasilar thrombo-occlusive lesions appear particularly likely to result in repetitive ischemic symptoms and in infarction due to hemodynamic insufficiency. The authors present their experience with 45 patients with symptomatic intracranial vertebrobasilar vascular disease despite maximal medical therapy. The specific operative approaches for intracranial vertebral artery endarterectomy and extracranial to intracranial posterior circulation revascularization procedures are outlined.