MEDICAL PRACTICE R Boet HT Wong Vertebrobasilar artery dissection: SCH Yu current practice WS Poon !"#$%&'()"*+,- ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ Nine patients with vertebrobasilar artery dissections who presented with neurological symptoms or subarachnoid haemorrhage were identified and treated in the Neurosurgical Unit at the Prince of Wales Hospital in Hong Kong. An account of these patients is given and their treatment described. This paper further reviews selected literature to outline the concepts and appropriate management of vertebrobasilar artery dissections. !"#$%&'()*+,-./0'(123456789:;<=>? !"#$%&'()*+,-./012(34#$56789:;, !"#$%&'()*+,-./0123456347)89:;<) !" Introduction Vertebral artery dissections (VADs) are increasingly recognised as a cause of subarachnoid haemorrhage (SAH) or cerebrovascular ischaemia. These dissections may occur in the extracranial or intracranial segments of the vertebral artery; dissections in the latter may extend into the basilar artery. Vertebral artery dissections, which are potentially fatal, have no clearly stratified treatment protocols in the literature. With the introduction of endovascular treatment modalities in the management of cerebrovascular disease, however, several options have become available to physicians in the treatment of VADs. We report a series of patients with VADs and use these cases to illustrate the different treatment modalities available in contemporary neurovascular medicine. Key words: Case series Aneurysm, dissecting; Basilar artery; Case 1 Subarachnoid hemorrhage; A 54-year-old hypertensive man experienced a sudden onset of severe headache Vertebral artery and neck pain. On admission, the patient was fully conscious and demonstrated ! no focal neurological deficit. A computed tomography (CT) scan of the brain !"# $ revealed SAH. A digital subtraction angiogram (DSA) revealed a right-sided !" intracranial fusiform vertebral artery aneurysm. The patient subsequently !"#$ underwent endovascular obliteration of the lesion by complete occlusion at the site of pathology using six Guglielmi detachable coils (GDCs). A repeat DSA 6 months later revealed complete occlusion of the lesion. The patient made a full recovery. HKMJ 2002;8:33-8 The Chinese University of Hong Kong, Case 2 Prince of Wales Hospital, Shatin, Hong A 54-year-old man experienced a sudden severe headache and was admitted Kong: to hospital fully conscious and with no focal neurological deficit. A CT scan of Department of Surgery the brain revealed SAH and intraventricular haemorrhage. A DSA demonstrated R Boet, FCSSA, FHKAM (Surgery) HT Wong, MB, ChB, MRCS a right-sided intracranial fusiform vertebral artery aneurysm just proximal to the WS Poon, FRCS, FHKAM (Surgery) origin of the posterior inferior cerebellar artery (PICA). The patient underwent Department of Diagnostic Radiology and endovascular occlusion of the lesion at the site of pathology using nine GDCs, Organ Imaging resulting in complete occlusion and leaving the PICA intact, as evident from SCH Yu, FRCR, FHKCR backflow during a contralateral vertebral artery injection. The patient made Correspondence to: Dr R Boet a full recovery but refused follow-up angiography. HKMJ Vol 8 No 1 February 2002 33 Boet et al Case 3 A 63-year-old diabetic and hypertensive man was admitted to hospital after a sudden collapse. He was confused and had mild right hemiparesis. A CT scan of the brain revealed SAH and hydrocephalus that required a ventriculostomy. An initial DSA was not helpful in establishing the cause of SAH, as the patient was restless and only limited images could be acquired. The patient subsequently had a ventriculo- peritoneal shunt inserted, followed by a second DSA, which demonstrated a left-sided intracranial fusiform vertebral artery aneurysm. Because the DSA suggested that the origin of the PICA was involved in the aneurysm, a surgical trapping procedure was performed. During the operation, a very small PICA was encountered and preserved. The patient made a good recovery and is independent for daily activities. Case 4 Fig 1. Spin-echo T1-weighted fat suppression axial magnetic A 43-year-old man presented to hospital after a first-time resonance imaging at the C3 level, showing a haematoma in generalised convulsion. A CT scan of the brain revealed the wall of the left vertebral artery and narrowing of the SAH. A DSA revealed a right-sided intracranial fusiform lumen (white arrow) vertebral artery aneurysm just proximal to the PICA. Endovascular occlusion of the aneurysm was performed using nine GDCs detached at the site of pathology. A contralateral vertebral artery injection demonstrated good cross flow into the right PICA. The patient made a good recovery and a repeat DSA several months later revealed persistent complete occlusion. Case 5 A 58-year-old hypertensive man presented to hospital with sudden onset of left hemiplegia. A CT scan and magnetic resonance imaging (MRI) of the brain demonstrated a pontine infarct and ectatic left vertebral and basilar arteries with haemorrhage in the wall of these vessels. A DSA confirmed vertebrobasilar dolichoectasia. The clinical and radiological features suggested a diagnosis of vertebrobasilar dissection. In hospital, the patient experienced a sudden deterioration in level of consciousness, which was thought to result from an extension of the dissection, as repeat brain scanning revealed no additional haemorrhage. To prevent further dissection, while preserving flow through the basilar artery, endovascular stenting of the affected segment was performed using three coronary artery stents. The procedure was uncomplicated and technically successful, but the patient did not regain consciousness and died during the admission. Case 6 A 35-year-old woman presented to hospital with a 2-week history of moderately severe neck pain radiating to the Fig 2. Three-dimensional time-of-flight magnetic resonance occipital region. This did not resolve with the use of routine angiogram showing narrowing of the left vertebral artery at C2/C3 level (white arrow) analgesics. There were no other symptoms or signs. Magnet- ic resonance imaging of the neck revealed haemorrhage in prevent ischaemic complications. A follow-up MRA the wall of the left vertebral artery (Fig 1), and a magnetic demonstrated resolution of the lesion and anticoagulation resonance angiogram (MRA) demonstrated an irregular area therapy was discontinued. in the left extracranial vertebral artery at cervical level C2 to C3 (Fig 2). The clinical and radiological features were Case 7 thought to represent an extracranial VAD (ECVAD) and the A 55-year-old man presented to hospital having collapsed patient received anticoagulation therapy for 3 months to while playing chess in a park. On examination he was dull 34 HKMJ Vol 8 No 1 February 2002 Vertebrobasilar artery dissection Case 8 A 50-year-old man presented with an SAH, localised on DSA to an intracranial dissection of the vertebral artery, just proximal to the PICA. Endovascular occlusion with seven GDCs was performed, sparing the PICA as demon- strated on contralateral vertebral artery angiography. This patient is still awaiting follow-up angiography. Case 9 A 16-year-old girl presented with sudden onset of dizziness and vomiting. A CT scan revealed bilateral cerebellar infarcts. A DSA revealed a right-sided extracranial dissection of the vertebral artery at the C1 to C2 level, with absent filling of the peripheral right posterior cerebral artery, the right superior cerebellar artery, and the right PICA. The patient was commenced on anticoagulation therapy but due to clinical deterioration and cerebellar swelling, subsequently underwent posterior fossa decompression and infarct resection. She made a slow but steady recovery following surgery, and currently is moderately disabled but Fig 3. Digital subtraction angiogram of the right vertebral independent for daily activities. After 3 months of artery demonstrating a fusiform dissecting aneurysm distal to the posterior inferior cerebellar artery, but proximal to the anticoagulation therapy, a repeat DSA revealed thrombosis vertebrobasilar junction of the right vertebral artery, but a completely normal posterior circulation following left vertebral artery injection. but conscious, and had no clinical features other than Anticoagulation therapy was subsequently discontinued. neck stiffness. A CT scan of the brain revealed diffuse SAH, which was prominent in the posterior fossa. A DSA revealed Discussion a right-sided intracranial fusiform vertebral artery aneurysm distal to the PICA, but not extending into the basilar artery Vertebral artery dissections may occur in extracranial and (Fig 3). Endovascular occlusion of the aneurysm was intracranial segments of the vertebral artery.1 Extracranial performed using seven GDCs detached at the site of VADs are far more common than their intracranial counter- pathology, but sparing the PICA. Contralateral vertebral parts and generally have a good prognosis.2-4 Patients with injection revealed good filling of the posterior circulation ECVADs often present with neck pain and occipital (Fig 4). The patient made a good recovery. Subsequently, headache.1,2,4,5 If neurological symptoms and signs do not follow-up angiography revealed persistent complete accompany these features, a dissection is often not suspected occlusion of the aneurysm. as a possible cause of the pain. The patient may subsequently experience the complication of vertebrobasilar ischaemia, which may occasionally