Profound Hypothermia and Circulatory Arrest with Skull Base Approaches for Treatment of Complex Posterior Circulation Aneurysms

Summary  Objective. Cardiopulmonary bypass with profound hypothermia and circulatory arrest has seen a resurgence as an adjunct technique in neurological surgery. We report our experience with this technique in treating seven complex vertebro-basilar aneurysms.  Methods. Skull base approaches were used in all cases, providing excellent exposure and minimizing brain retraction. There were six basilar artery aneurysms and one giant fusiform vertebro-basilar artery aneurysm. All aneurysms but one had an apparent neck, which could be clipped. The fusiform vertebro-basilar artery aneurysm was trapped, partially resected, and the circulation was re-established with a saphenous vein graft from the cervical internal carotid artery to the mid-basilar artery.  Results. Five patients had an excellent outcome and two had a good outcome at one year or at latest follow up. Two of the patients showed improvement of neurological deficits which were present before the surgical intervention.  Conclusion. Applying very strict selection criteria in this small series of patients with posterior circulation aneurysms, excellent or good results were achieved using the profound hypothermic circulatory arrest technique.     

Giant, fusiform and dissecting aneurysms at the vertebro-basilar junction--report of five cases and their clinical pathophysiological aspects

Five cases of giant, fusiform, and dissecting aneurysms of the vertebro-basilar junction, in which direct surgical treatment was not feasible, are reported. Their initial symptoms were as follows: 3 subarachnoid hemorrhages (2 fusiform aneurysms, 1 giant aneurysm), 1 mass sign (giant aneurysm), and 1 ischemic sign (dissecting aneurysm). In two patients, one with a giant and one with a dissecting aneurysm, preoperative proximal vertebral occlusion was carried out by inflated balloon for 30 to 100 minutes, under observation of clinical signs and measurement of distal arterial pressure. This catheter technique with an inflated balloon provides the means to assess the effect of vertebral artery occlusion in the alert patient, and to determine if occlusion is tolerated or not. In one case with a giant aneurysm, the proximal vertebral artery was occluded extracranially with no complications and no recurrent subarachnoid hemorrhage for 1 year. The other four patients (1 thrombosed giant aneurysm, 2 fusiform aneurysms, 1 dissecting aneurysm) whose contralateral vertebral arteries were hypoplastic, and who refused to operation, were treated conservatively for 6 months to 6 years. Their outcomes were better than expected, with no recurrent subarachnoid hemorrhage nor aggravation of clinical symptoms except for the one case with a dissecting aneurysm whose deterioration was presumed attributable to late cerebellar cortical atrophy.     

Unruptured fusiform aneurysms of the posterior circulation with thalamic infarction

Three patients with unruptured fusiform aneurysms of the posterior circulation presented with nonhemorrhagic thalamic infarctions. All of the aneurysms were seen on enhanced computed tomographic (CT) scans preangiographically. Although unruptured fusiform aneurysms are probably a rare cause of nonhemorrhagic thalamic infarction, their importance lies in the therapeutic implications of this diagnosis. In patients with nonhemorrhagic thalamic infarction, we suggest careful scrutiny of the blood vessels on enhanced CT scans.     

Multiple giant fusiform aneurysms with hydrocephalus

Multiple giant fusiform aneurysms are uncommon. We report such a case of multiple giant fusiform aneurysms involving both internal carotid arteries and the basilar artery associated with hydrocephalus. The neurological deficits presented in this case were due to pontine infarction, which was suspected to be produced by thrombosis from the aneurysm, and a hydrocephalus might have been caused by a "water-hammering" effect of the elongated basilar artery.     

Combined endovascular stent implantation and coil embolization for the treatment of a vertebro-basilar fusiform aneurysm: technical case report

We describe a case of the combined application of endovascular stent implantation and Guglielmi detachable coil packing for the treatment of a vertebro-basilar fusiform aneurysm and review the literature on stent placement to treat cerebral aneurysms. A 70-year-old female presented with an acute headache from subarachnoid hemorrhage. A fusiform aneurysm with a broad-based neck and dome, measuring 15 mm, involving the union of the vertebral arteries and the proximal basilar artery was demonstrated on cerebral angiography. The aneurysm was judged to be inoperable and treated conservatively. Twelve days later the patient was transferred to our hospital for endovascular therapy. An intravascular stent (MultiLink) was placed across the base of the aneurysm through the right vertebral artery. After this, coil placement in the aneurysm around the stent was performed via a microcatheter guided from the left vertebral artery. After that a microcatheter was guided from the right vertebral artery through the interstices of the stent into the aneurysm, and additional coils were placed. Final angiography showed subtotal occlusion of the aneurysm and excellent blood flow of the parent artery through the stent. There were no new neurological deficits. Neither rerupture nor ischemic event has occurred. The use of stents provides another treatment for managing the difficult entity of intracranial aneurysms.     

Encephalo-myo synangiosis (EMS) in the vertebrobasilar occlusive disease. Case reports

Two case of vertebro-basilar insufficiency treated with infratentorial (IT) Encephalo-Myo-Synangiosis (EMS) using the pedicled occipitalis muscle flap, are presented. IT EMS was carried out for revascularization of the vertebro-basilar system. None of these cases has suffered from either carotid or vertebrobasilar insufficiency during seven years follow-up period. As far as we know this is the first report of successful IT EMS for vertebro-basilar insufficiency.     

Natural history of giant intracranial aneurysms

The outcome of a consecutive series of 28 patients with giant aneurysm who had been followed without surgery from one month to 12 years after the diagnosis was made, are presented with reviewing their radiological and clinical features. Symptoms and signs were directly or indirectly attributable to the intracranial mass effect and nine patients (32%) presented subarachnoid hemorrhage. Subarachnoid hemorrhage was frequently associated with intraventricular or intracerebral hemorrhage, a poor clinical grading at admission and a high mortality. Subarachnoid hemorrhage was most often recorded from the giant aneurysm at the supraclinoid portion of the internal carotid artery and the vertebro-basilar artery, but the rupture from the intracavernous giant aneurysm, completely thrombosed giant aneurysm and the fusiform type of giant aneurysm was rare. The mortality rate in 28 cases for the above follow up period was 46% (13 in 28 cases) and major morbidity occurred in 11% (3 in 28 cases). The above outcome of non operated giant aneurysm cases may justify the surgical management of the giant aneurysm, but as the intracavernous giant aneurysm and thrombosed giant aneurysm are relatively harmless, surgical indication should be carefully decided, especially in the older patients.     

Persistent primitive proatlantal intersegmental artery (PPPIA) presenting with cerebral infarction

A case of persistent primitive proatlantal intersegmental artery (PPPIA) is reported. A 65-year-old male with treated hypertension was admitted to our clinic complaining of dysarthria and hemiparesis of sudden onset two days after the ictus. CT revealed spotty low-density lesions in the left corona radiata and bilateral thalami with bilateral watershed infarction. MRI findings were also compatible with cerebral infarction. Left common carotid angiography demonstrated a large anastomosis between the external carotid artery and the vertebral artery at the proatlantal region. Neither of the vertebral arteries were visualized on digital subtraction aortography. All the blood circulation of the vertebro-basilar system was through this anastomotic artery (PPPIA). A flow study revealed hypoperfusion in the territory of the left middle cerebral artery on 133Xe SPECT. Bone window CT of cervical vertebrae revealed hypoplasia of the left transverse foramen in C2, C3, C4, C5, C6 vertebrae. This case is very suggestive of an anaplasia or hypoplasia of the vertebral arteries. The etiology of his left frontal infarction seemed to be a blood-stealing phenomenon of long standing, from the anterior to the posterior circulation through the PPPIA.     

Conservative (labyrinth-preserving) transpetrosal approach to the clivus and petroclival region--indications, complications, results and lessons learned

OBJECTIVE: Tumours or vascular lesions of the clivus and juxtaclival region present a unique challenge to neurosurgeons and a variety of techniques, with a wide spectrum of complexity, have been advocated. This report presents the use of a conservative transpetrosal approach which combines partial removal of the postero-lateral petrous bone with preservation of the labyrinth, with particular focus on efficacy and the reduction of complications. PATIENTS AND METHODS: Over 9 years, 52 patients underwent a conservative combined supra-infratentorial, labyrinth-preserving transpetrosal approach. There were 32 women and 20 men; 33 had tumour lesions including 22 patients with a clival or petroclival meningioma. Among the 19 patients with a vascular lesion, 12 patients had a basilar artery trunk aneurysm, including one giant midbasilar aneurysm. 3 Patients had vertebro-basilar junction aneurysms, and 4 patients had a pontine cavernoma. Data on the clinical features, investigations and operative techniques were extracted from the patient's case records. Outcome was assessed by serial examinations of the patients or by telephone interview with the treating physician, and in survivors graded as excellent, good or poor. RESULTS: 52 patients, 23 patients (44%) had an excellent outcome, in 21 patients (41%) the outcome was good and in 7 patients (13%) the outcome was poor. One patient with a complex fusiform basilar trunk aneurysm, operated upon as an emergency, died in the postoperative period. Total resection was achieved, as demonstrated by follow-up MRI in 20 of 33 patients with a tumour, including 15 of 22 patients with clival or petro-clival meningiomas. All vascular lesions were treated effectively and in 14 patients with a basilar or vertebro-basilar junction aneurysm, clipping of the aneurysm was achieved. In one patient, a giant calcified vertebro-basilar junction aneurysm was resected. New cranial nerve deficits or an accentuation of a pre-existing deficit, occurred in 8 patients with a tumour and 4 patients with a vascular lesion. Complications included: temporary conductive hearing deficit in 4 patients, a minor laceration of the sigmoid/transverse sinus in 4 and transient post-operative CSF leakage in 12 patients. Temporary lumbar drainage resulted in sealing of the CSF leak in 8 patients, but in 3 patients a permanent ventriculo-peritoneal shunt had to be implanted. CONCLUSION: When based on adequate experience in skull base surgery, the combined supra-infratentorial, conservative transpetrosal approach, with preservation of the labyrinth, allows direct and wide exposure of a large variety of tumour and vascular lesions located along the supra- and infratentorial juxta-clival area; little or almost no retraction of neurovascular structures is needed and with adherence to important principles, complications related to the approach can be minimised.     

Giant cerebral aneurysms

Summary A review of the literature regarding the clinical aspects, diagnosis and management of giant aneurysms and examples from the series of 30 cases of these lesions draw attention to the following aspects: – clinical presentation:a large proportion of aneurysms, measuring more than 2.5 cm in diameter presents with signs and symptoms suggesting a tumorous lesion. Cranial nerve palsies are a frequent sign. However, approximately 60 per cent of cases present with subarachnoid haemorrhage on admission or with history of SAH in the past.In contrast to smaller aneurysms giant aneurysms involve mainly the ICA and the VB system and less frequently the ACA complex.– radiology:Giant aneurysms have fairly characteristic CT appearance but must be differentiated from some basal tumours like meningioma, neurinoma, pituitary adenoma, germinoma. Angiography remains the main diagnostic tool. Subdivision of giant aneurysms into five types plus fusiform aneurysm based on the degree of thrombosis and degree of opacification on angiogram is justified in view of its implications for the management. Serpentine type of giant aneurysm is a particular form of a partially thrombosed lesion and it is not limited to the MCA. Giant partially thrombosed aneurysms may act as a source of emboli.– management:Surgical treatment still remains a formidable task. Direct clipping of the neck is often impossible. In the majority of cases temporary occlusion of the parent vessel proximally and distally to the lesion is necessary at the time of operation of permanent occlusion of the parent vessel, and remains the only possibility. In such cases a bypass operation should be considered and should be done at the same time as staged occlusion. There is good evidence that a bypass is also of value in patients in whom only the extracranial ICA is ligated.– morbidity and mortality are higher than in other types of aneurysms. Prognosis in non-treated, nonthrombosed or partially thrombosed giant aneurysms particularly of the vertebro-basilar system is extremely poor.     

SEP monitoring during balloon occlusion test or operation for vertebro-basilar aneurysms

SEP (somatosensory evoked potential) monitoring was carried out on seven patients with vertebro-basilar aneurysms during balloon occlusion test, during operation, or after operation. In the patient (case 5) with basilar tip aneurysm, the amplitude of N20 remarkably decreased and this finding closely correlated with disturbed consciousness during transient balloon occlusion of the basilar artery. In another patient (case 6) with vertebral dissecting aneurysm, cerebellar retraction caused transient prolongation of N20 latency during operation. In another case, postoperative SEP monitoring revealed marked reduction of N20 amplitude in the patient (case 7) who showed disturbed consciousness and bilateral oculomotor palsy after operation for basilar aneurysms, but who showed no abnormality in postoperative ABR (auditory evoked brainstem response). The other four patients showed no neurological deterioration and no SEP change during transient balloon occlusion of the parent arteries. Because of the high rate of "false-negative" findings, it remains unclear whether SEP monitoring during surgery for vertebrobasilar aneurysms is of value to predict postoperative deficit due to brainstem ischemia. In our study, however, the changes of SEP were well correlated with neurological deterioration and/or the location of postoperative infarction. In conclusion, SEP monitoring during balloon occlusion tests or operations for vertebro-basilar aneurysms is considered to be useful in predicting ischemic complication of the brainstem caused by the occlusion of the parent artery. However other methodologies have to be developed in order to monitor the pyramidal tract and reticular activating system of the brainstem more accurately.     

Excision and end-to-end anastomosis of a fusiform aneurysm of the distal posterior inferior cerebellar artery associated with ischemia--case report.

A 35-year-old male with a sudden onset of severe vertigo and vomiting had a fusiform aneurysm of the distal portion of the left posterior inferior cerebellar artery. The symptoms were caused by cerebellar infarction probably due to an embolism from the aneurysm. The aneurysm was excised and the artery reconstructed by end-to-end anastomosis with an excellent outcome. Histological examinations showed mural thrombus but no wall dissection.     

Short-segment Internal Trapping for Symptomatic Thrombosed Large Fusiform Vertebral Artery Aneurysms (Bird’s Nest Trapping): A Technical Note

Internal trapping with coils is an established treatment of symptomatic large non-branching thrombosed fusiform vertebral artery aneurysms (VAA). However, when perforators arise near the aneurysm neck, parent artery occlusion has a high risk of causing medullary infarction. As an alternative treatment, we performed short-segment internal trapping of the artery using n-butyl-2-cyanoacrylate (NBCA) and coils (bird’s nest trapping). Before treatment, perianeurysmal perforators are carefully detected using high-resolution three-dimensional rotational angiography (3DRA). Double microcatheters are advanced to the distal portion of the aneurysm through a balloon guiding catheter where coils are deployed without tight packing. Then, NBCA is injected into the coil mass, taking care to preserve perforators and significant branches. The same maneuver is repeated in the proximal portion of the aneurysm. Coil placement is avoided within the middle of the aneurysm; however, if necessary, only a small number of coils are placed to prevent worsening of mass effect. Two quinquagenarian males presented with a large thrombosed fusiform VAA that caused symptoms due to mass effect. In each case, perforators arose from the parent artery and short-segment internal trapping with NBCA and coils was performed. Symptoms improved after treatment and follow-up imaging confirmed aneurysm shrinkage with no long-time recurrence. In symptomatic large fusiform VAAs where the distance from the lesion to important perforators is extremely short, internal trapping using a combination of NBCA and coils can be more useful than conventional internal trapping.     

Surgical approaches for vertebro-basilar trunk aneurysms located in the midline

Summary Fourteen cases of midline vertebro-basilar trunk aneurysms were operated on by four routes of surgical approach: middle fossa anterior transpetrosal approach (ATP), presigmoid transpetrosal approach (PTP), conventional lateral suboccipital approach (LSO) or suboccipital transcondylar approach (STC). There was no mortality, but the morbitity was different depending on the surgical approach. In basilar trunk aneurysms located higher than the internal auditory canal, excellent results were obtainable by ATP, especially in the case of posteriorly projecting aneurysms. For midline vertebral aneurysms located lower than the internal auditory canal, STC resulted in less surgical complications than LSO. Extradural resection of the jugular tubercle was necessary for aneurysms located on the distal vertebral artery at or close to the vertebro-basilar junction. For vertebro-basilar junction aneurysms located at the level of the internal auditory canal, hearing was preserved by STC, but not by ATP or PTP. However, choice of the surgical approach may depend on the direction of the aneurysm and the technical accessibility of the skull base. All these skull base approaches reduced surgical complications of retraction damage to the cranial nerves and the brain stem. This holds true for all aneurysms arising from the midline vertebro-basilar trunk.     

Conservative (labyrinth-preserving) transpetrosal approach to the clivus and petroclival region – indications,complications, results and lessons learned

Objective. Tumours or vascular lesions of the clivus and juxtaclival region present a unique challenge to neurosurgeons and a variety of techniques, with a wide spectrum of complexity, have been advocated. This report presents the use of a conservative transpetrosal approach which combines partial removal of the postero-lateral petrous bone with preservation of the labyrinth, with particular focus on efficacy and the reduction of complications. Patients and methods. Over 9 years, 52 patients underwent a conservative combined supra-infratentorial, labyrinth-preserving transpetrosal approach. There were 32 women and 20 men; 33 had tumour lesions including 22 patients with a clival or petroclival meningioma. Among the 19 patients with a vascular lesion, 12 patients had a basilar artery trunk aneurysm, including one giant midbasilar aneurysm. 3 Patients had vertebro-basilar junction aneurysms, and 4 patients had a pontine cavernoma. Data on the clinical features, investigations and operative techniques were extracted from the patients case records. Outcome was assessed by serial examinations of the patients or by telephone interview with the treating physician, and in survivors graded as excellent, good or poor. Results. 52 patients, 23 patients (44%) had an excellent outcome, in 21 patients (41%) the outcome was good and in 7 patients (13%) the outcome was poor. One patient with a complex fusiform basilar trunk aneurysm, operated upon as an emergency, died in the postoperative period. Total resection was achieved, as demonstrated by follow-up MRI in 20 of 33 patients with a tumour, including 15 of 22 patients with clival or petro-clival meningiomas. All vascular lesions were treated effectively and in 14 patients with a basilar or vertebro-basilar junction aneurysm, clipping of the aneurysm was achieved. In one patient, a giant calcified vertebro-basilar junction aneurysm was resected. New cranial nerve deficits or an accentuation of a pre-existing deficit, occured in 8 patients with a tumour and 4 patients with a vascular lesion. Complications included: temporary conductive hearing deficit in 4 patients, a minor laceration of the sigmoid/transverse sinus in 4 and transient post-operative CSF leakage in 12 patients. Temporary lumbar drainage resulted in sealing of the CSF leak in 8 patients, but in 3 patients a permanent ventriculo-peritoneal shunt had to be implanted. Conclusion. When based on adequate experience in skull base surgery, the combined supra-infratentorial, conservative transpetrosal approach, with preservation of the labyrinth, allows direct and wide exposure of a large variety of tumour and vascular lesions located along the supra- and infratentorial juxta-clival area; little or almost no retraction of neurovascular structures is needed and with adherence to important principles, complications related to the approach can be minimised.Published online July 23, 2003     

Revascularization of vertebro-basilar occlusive disease

Various surgical techniques have been reported for vascular reconstruction in cases of vertebro-basilar occlusive disease, but sufficient study has not been made on the question of which technique should be applied in various pathological conditions. Based on our experience, we have examined the advantages and disadvantages of these techniques. In 34 patients with clinically and angiographically diagnosed vertebro-basilar insufficiency, the reconstructive vascular surgery to the posterior circulation was performed. Preoperatively, 24 had vertebro-basilar TIAs, 2 had RIND, 3 had progressing symptoms and 5 had brain stem infarctions verified by persistent deficits. In the 18 patients with intracranial vertebro-basilar occlusive lesions, the bypass were done to the proximal posterior inferior cerebellar artery in 7 cases, proximal superior cerebellar artery in 9 cases, posterior cerebral artery in one and anterior inferior cerebellar artery in one. In the 16 patients with extracranial occlusive lesions of vertebral artery, endarterectomy or subclavian-vertebral transposition was performed. With the exception of one of the progressing stroke cases, in which the surgery was ultimately too late, there were no cases in which neurological symptoms become aggravated following operation. Patency was 94% (32/34). In light of these findings, the following conclusions concerning the operative indication and the selection of the technique have been drawn. In cases with occlusive lesions of basilar artery, the first choice should be bypass to the proximal superior cerebellar artery. In cases with occlusive lesions of vertebral artery, bypass to the posterior inferior cerebellar or superior cerebellar or anterior inferior cerebellar artery should be performed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dejerine-Roussy syndrome following endovascular parent artery occlusion for an unruptured posterior cerebral artery aneurysm (P2 segment): case report

A right posterior cerebral artery (PCA) fusiform aneurysm was incidentally discovered in a 53-year-old man. Although the aneurysm was asymptomatic, treatment of the aneurysm was indicated to avoid possible hemorrhage and/or mass effect. Since the patient tolerated temporary balloon occlusion of the right PCA at P1-P2 segments and sufficient collateral flow to the right temporo-occipital region was observed during such occlusion, parent artery occlusion as well as intraluminal occlusion of the aneurysm was performed with Guglielmi detachable coils. The patient did not develop neurological deficit immediately after embolization. However, he subsequently developed Dejerine-Roussy syndrome due to an infarction in the territory of the thalamogeniculate artery. Parent artery occlusion together with intraluminal aneurysmal obliteration is an useful treatment for a fusiform aneurysm of the PCA. However, ischemic complication in the territory of the perforating artery can not be predicted.     

Aneurysms of the vertebro-basilar system: Clinical analysis and follow-up result

Summary 336 cerebral aneurysms were treated during the past 18 years. Amongst these, 30 patients harboured aneurysms in vertebro-basilar circulation and form the subject material to be analysed. 17 were non-surgically treated whilst 13 cases received surgical treatment. In the group of non-surgical treatment, 6 were found in a moribund stage on admission, 9 had rebled during hospitalization and died. 2 other patients with large or giant aneurysms were treated palliatively and conservatively. They still survived over 18 months. 12 aneurysms were surgically clipped and 1 was wraped with muscle. 2 of them died 1 week postoperatively due to pulmonary embolism. Risk factors are discussed. In contrast to the aneurysms of other circulatory territories vertebro-basilar aneurysms should be operated at the earliest possible opportunity; waiting does not provide an additional advantage to offset the risk of high mortality and morbidity after recurrent haemorrhage and vasospasm in this region.     

Four cases of fusiform posterior inferior cerebellar artery aneurysms successfully treated by trapping and occipital artery-PICA bypass

Aneurysms located on the proximal portion of the posterior inferior cerebellar artery (PICA) are rare, and even rarer are fusiform aneurysms in this location. Therefore the principles of surgical management are poorly understood and still subject to debate. The management plan for these lesions is based on the proper understanding of the PICA anatomy, and particularly the origin of important perforating arteries. As many anatomic variations of PICA can be observed and the perforator's origin is sometimes in complex anatomical relations with the aneurysm, the management has to be individualized in each case. The objective of management is to exclude of the aneurysm from the circulation while preserving the perforator and distal flow. We report four cases of PICA fusiform aneurysms of the anterior or lateral medullary segments which were treated successfully with trapping of the abnormal arterial segment and distal revascularization of PICA. Trapping was adjusted to the specific anatomical circumstances in each case, preserving perforators to the maximum and revascularizing (OA-distal PICA) distal territory.     

Aplasia of both vertebral arteries

An angiographically verified case of aplasia of both vertebral arteries is described. Blood was supplied to the whole vertebro-basilar territory by the hypertrophied left occipital artery the direct continuation of which was the basilar artery of the brain. The article also deals with other anomalies of the vertebral arteries which are important in surgery.