Combined reconstruction of the vertebral and carotid artery in one single procedure

Multidisciplinary treatment of posterior circulation ischemia

Compromise of blood flow to the brain leads to cerebral ischemia, which if left untreated may even result in cerebral infarction. This has been the main cause of major morbidity and mortality over the years in the US and around the world. Cerebral ischemia to the posterior fossa is more critical and difficult to treat. This is primarily due to complex anatomy and physiology of the posterior fossa cerebal circulation. There has been multiple modalities tested over the years to treat posterior fossa ischemia which have definitely contributed in the outcome in patients with this complex problem. Improving the blood flow in the areas of brain at risk in properly selected patients could prevent impending cerebral ischemia and infarction. Today, there are mainly three types of treatment offered to patients with posterior cerebral ischemia. These are (a) medical, (b) endovascular and (c) surgical. The recent advances in technology, the diagnosis and mode of therapy, has definitely improved the outcomes of cerebral ischemia. We discuss the multidisciplinary treatment of posterior circulation ischemia. Various pre-operative and operative techniques involved in treating patients with posterior cerebral ischemia are discussed.

Microsurgical anatomy of cerebral revascularization. Part II: Posterior circulation

Object. Revascularization is an important component of treatment for complex aneurysms, skull base tumors, and vertebrobasilar ischemia in the posterior circulation. In this study, the authors examined the microsurgical anatomy related to cerebral revascularization in the posterior circulation and demonstrate various procedures for bypass surgery.

Methods. The microsurgical anatomy of cerebral and cerebellar vessels as they relate to revascularization procedure and techniques, including extracranial-to-intracranial bypass grafting, arterial interposition grafting, and side-to-side anastomosis, were examined by performing stepwise dissections in 22 adult cadaveric specimens. The arteries and veins in the specimens were perfused with colored silicone.

Dominant cerebral and cerebellar revascularization procedures in the posterior circulations include superficial temporal artery (STA)—posterior cerebral artery (PCA), STA—superior cerebellar artery (SCA), occipital artery (OA)—anterior inferior cerebellar artery, OA—posterior inferior cerebellar artery (PICA), and PICA—PICA anastomoses. These procedures are effective in relatively small but critical areas including the brainstem and cerebellum. For revascularization of larger areas a saphenous vein graft is used to create a bypass between the PCA and the external carotid artery. Surgical procedures are generally difficult to perform in deep and narrow operative spaces near critical vital structures.

Conclusions. Although a clear guideline for cerebral revascularization procedures has not yet been established, it is important to understand various microsurgical techniques and their related anatomical structures. This will help surgeons consider surgical indications for treatment of patients with vertebrobasilar ischemia caused by aneurysms, tumors, or atherosclerotic diseases in the posterior circulation.

Thyrocervical to vertebral artery transposition and ipsilateral carotid endarterectomy

BACKGROUND

We report a new method for treating patients with symptomatic high-grade stenosis of the proximal vertebral artery associated with high-grade stenosis of the ipsilateral carotid artery.

METHODS

Our patient had high-grade stenosis of the proximal right vertebral artery as well as high-grade stenosis of the ipsilateral carotid artery and suffered continued posterior circulation ischemic neurological deficits despite anticoagulation.

RESULTS

The patient was successfully treated with a carotid endarterectomy and thyrocervical-to-vertebral artery transposition in a single operation.

CONCLUSION

This procedure has the advantage in this setting of avoiding additional cross clamping on the diseased carotid artery that would normally be required for the vertebral-to-carotid artery transposition with carotid endarterectomy. Also, thrombosis at one anastamosis site would not endanger the other site as well.