Double aneurysms at distal basilar artery: report of nine cases

OBJECTIVE: Double aneurysms at the basilar bifurcation and the basilar artery-superior cerebellar artery (BA-SCA) junction have not been well investigated previously. We analyzed nine patients with double basilar aneurysms to evaluate their radiological characteristics and suitable treatment. METHODS: Between 1978 and 1999, the incidence of double aneurysms was 5.3% in our 169 consecutive surgical cases of distal BA aneurysms. Seven (77.8%) of the nine patients with double aneurysms had associated aneurysms in the anterior circulation. Open surgery was performed in eight patients and coil embolization in one. The patients' radiological findings, choice of treatment, and surgical results were analyzed retrospectively. RESULTS: The size of the basilar bifurcation aneurysms ranged from 2 to 8 mm (mean, 4.4+/-2.0 mm), and the size of the BA-SCA aneurysms ranged from 2 to 12 mm (mean, 5.6+/-3.6 mm). Diagnosis of double basilar aneurysms was difficult when the basilar trunk had twisted or when size differences between the two aneurysms were apparent. The angle between the posterior cerebral artery and SCA appeared to be wider on the same side as the BA-SCA aneurysms (101+/-42 degrees) than on the opposite side (26+/-24 degrees). The P1 segment of the posterior cerebral artery originated in an upright direction from the basilar bifurcation between the two basilar aneurysms in seven patients. The pterional approach was used in eight patients; 14 basilar aneurysms were successfully clipped and 2 were wrapped. Nonstraight clips with short blades were used frequently. Coil embolization of double aneurysms was required twice in one patient because the initial angiogram was misinterpreted as a single aneurysm and its bleb. CONCLUSION: Measurement of the posterior cerebral artery-SCA angle is a simple method to estimate the presence of BA-SCA aneurysms and to differentiate double aneurysms from a bilocular aneurysm at the basilar bifurcation. The pterional approach is suitable for clipping double basilar aneurysms because anterior circulation aneurysms often coexist, and the upstanding P1 segment is an obstacle in the subtemporal approach to the basilar bifurcation aneurysm. Nonstraight clips with short blades are convenient to avoid conflicting clips in the narrow surgical space.     

Variant aneurysms of the fenestrated basilar artery

Two cases of aneurysm occurring on a fenestrated basilar artery are reported. One patient had a saccular aneurysm in the typical location at the vertebrobasilar junction at the proximal end of the fenestrated basilar segment. The aneurysm sac projected dorsally into the brain stem. The other patient had a blister-like aneurysm distal to a fenestration of the terminal basilar artery. The development of a distal aneurysm on a fenestrated basilar artery is predictable based on the reported morphology of the vessel wall in this vascular anomaly.     

Endovascular treatment of basilar artery aneurysms

International experience regarding the treatment of basilar artery aneurysms using the Guglielmi Detachable Coil (GDC) system was reviewed. The four patient series included in this critique were composed of similar numbers of patients who had aneurysms that predominantly involved the basilar artery bifurcation and who presented clinically after a subarachnoid hemorrhage. Consistent results observed between the individual outcome experiences were as follows: (1) complication rates associated with the endovascular treatment of basilar artery aneurysms compared favorably with the historical rates associated with direct surgical clipping; (2) smaller aneurysms in this location could be more safely and completely occluded than their larger counterparts; (3) the endosaccular thrombus produced after GDC placement is a dynamic, rather than permanent, entity; (4) progressive thrombosis, thrombolysis, or compaction of the coil mass — singly or in combination — can account for changes in the extent of aneurysm occlusion observed over time; (5) even if an aneurysm could not be obliterated completely, treatment with GDC coils immediately after subarachnoid hemorrhage appeared to confer a protective effect upon patients compared to the natural history of untreated, ruptured intracranial aneurysms. In summary, these studies support the following conclusions regarding GDC-mediated electrothrombosis for the treatment of aneurysms: (1) aneurysm morphologies that are the most troublesome to treat by a conventional open surgical approach are also the most difficult to treat endovascularly; (2) although a useful therapeutic option for high-risk surgical candidates after aneurysmal hemorrhages, the endovascular treatment of intracranial aneurysms (basilar or otherwise) as more than a temporizing (i.e., not curative) intervention is not yet supported by data; (3) when comparing the complications and expenses associated with open surgical and endovascular therapy for aneurysms, long-term morbidity and cost analyses must incorporate the respective requirements for subsequent angiographic evaluation and repeat treatment sessions to address aneurysm residuals; (4) limited clinical and angiographic follow-up data preclude conclusions regarding the value of endovascular treatment for the management of asymptomatic aneurysms; (5) direct clip ligation of intracranial aneurysms remains the definitive treatment strategy until appropriate prospective, controlled, randomized studies prove otherwise.     

Supranuclear ophthalmoplegia with basilar artery aneurysms

In two patients, large aneurysms of the basilar artery produced a supranuclear gaze paresis, involving horizontal gaze in one case and vertical gaze in the other. In both cases the diagnosis was suggested by computed tomography and confirmed by vertebral angiography. Autopsy findings in one case confirmed the diagnosis. Although supranuclear gaze palsies must reflect damage to structures deep within the brain stem, these cases illustrate that an extrinsic lesion may produce such damage indirectly. Basilar artery aneurysm should be considered in patients presenting with supranuclear gaze paresis and long tract signs.     

Microneurosurgery for aneurysms of the basilar artery.

The authors report microsurgical treatment in 32 cases of basilar artery aneurysms, operated on with good results in 28 cases, fair results in one, and poor results in one; there were two deaths. Twenty-nine patients (91%) were able to return to social activities. Characteristics of the surgical techniques include 1) taking a transsylvian route; 2) retracting the M1 portion of the middle cerebral artery (occasionally the C1 portion of the internal carotid) medially with tapered brain retractors; and 3) approaching the aneurysm through and between perforators arising from the posterior cerebral artery in cases of high-placed basilar bifurcation. With regard to instrument improvements, tapered brain retractors, a multipurpose head frame, and bayonet clips (Sugita design) proved very helpful.     

Endovascular treatment of basilar artery trunk aneurysms

Background  

There has been little reported on the endovascular experience of basilar artery (BA) trunk aneurysms due to its low incidence. The purpose of this study is to report the results of endovascular treatment (EVT) of BA trunk aneurysms.     

Enlarging thrombosed aneurysm of the distal basilar artery

The case of a 65-year-old man who had partial left third nerve palsy is reported. Radiographic examination disclosed a completely thrombosed giant suprasellar aneurysm. Although an angiogram appeared to indicate that his aneurysm arose from the distal basilar artery, he was also noted to have an unusual and ectatic distal internal carotid artery on the left side, and this was also felt to be a potential source of the aneurysm. Operative exploration was performed and confirmed the basilar artery as the sight of origin, and definitive therapy was deferred. The patient's progress was monitored, and for 3 years his neurological course was stable and there was no change in his radiographic abnormalities. During the 6 months following this period, the patient developed signs and symptoms of progressing hydrocephalus and was found to have significant enlargement of his still completely thrombosed giant aneurysm. This complicated case highlights the controversy regarding the management of this difficult condition, particularly with regard to endovascular therapies, and also provides insight into the evolution of this dynamic disease process.     

Transpetrosal approach for aneurysms of the lower basilar artery

Extradural subtemporal access to the petrosal ridge and a resection of the anterior pyramidal bone produced direct observation of the lower basilar artery, with minimum retraction of the temporal lobe and preservation of the temporal bridging veins. Two patients with lower basilar trunk aneurysms facing toward the brain stem, were operated on by the "transpetrosal approach," with successful clipping of the aneurysms. Auditory function was preserved in one case. This approach decreases the possibility of retraction damage to the temporal lobe, brain stem, or cranial nerves, and may be helpful for surgery of aneurysms arising around the vertebrobasilar junction or at the origin of the anterior inferior cerebellar artery.     

Zygomatic temporopolar approach for basilar artery aneurysms

For surgery of upper basilar artery aneurysms, we have modified the temporopolar approach proposed by Sano by detaching the zygomatic arch to obtain a wide, shallow operating field. This approach seems to be suitable for anteriorly protruding, high-positioned, or large aneurysms of the upper basilar artery. We have used this zygomatic temporopolar approach in 4 patients with such aneurysms and obtained satisfactory results. In this paper, we detail the operative procedure and emphasize certain technical points to minimize temporal lobe retraction and to prevent oculomotor and facial nerve injuries.     

Perioperative morbidity and mortality of coronary artery surgery after the age of 70 years

The aim of this study was to compare the actual perioperative (operative and hospital) morbidity and mortality of coronary bypass surgery in patients aged 70 years or older and patients aged 69 years of younger. From January 1987 to September 1988, 102 patients aged 70 years or older underwent isolated aortocoronary bypass surgery. They were compared with the younger patients operated in the same period. Preoperative, operative and postoperative data were analyzed. There was no significant difference between the mortality and morbidity of the two groups. Morbidity was evaluated according to several parameters, low cardiac output, prolonged ventilation, cerebrovascular accident, transient ischemic attacks, pulmonary problems, psychosis, renal failure, wound problems and reoperations. Because this is a limited experience it may be premature to conclude than older patients can be operated on as safely as their young counterparts, but this study shows that age is not in itself a risk factor.     

Treatment of giant fusiform aneurysms of the basilar trunk with intra-aneurysmal and basilar artery coil embolization

OBJECTIVE: The authors report their experience in endovascular treatment of basilar artery (BA) trunk aneurysms by intra-aneurysmal and BA occlusion. METHODS: Four patients were referred to our hospital from 1995 until 2002 with variable clinical presentations and radiologic appearances. All the patients were subjected for tolerability to balloon BA occlusion test to verify the collateral supply from the posterior communicating arteries. The patients were treated by intra-aneurysmal embolization together with basilar artery occlusion. RESULTS: All the aneurysms were successfully isolated from the circulation. Transient postoperative neurologic deficits were constant findings in all the cases. Outcome was finally good for all the patients. CONCLUSIONS: Endovascular treatment of complex BA trunk aneurysm by intra-aneurysmal embolization and BA occlusion method is a valuable alternative for management and successful isolation in patients with good collateral arterial flow.     

Saccular aneurysms of the distal anterior cerebral artery

We report a series of 42 consecutive patients with aneurysms of the distal anterior cerebral artery (ACA). Of these, 36 patients had one aneurysm, 5 had two aneurysms, and one had three aneurysms. Thirty patients had a ruptured distal ACA aneurysm; among these patients, the size of the aneurysm was less than 5 mm in diameter in 20, 6 to 10 mm in 7, and larger than 11 mm in 3. Eighteen patients (42.9%) had multiple aneurysms, and distal ACA aneurysms were responsible for a subarachnoid hemorrhage in 10. Thirty-four patients underwent direct surgery, and 30 of these had excellent outcomes 3 months after surgery. The treatment of patients with distal ACA aneurysms is often technically difficult, because of their broad neck configuration and the coexistence of other aneurysms. Nevertheless, the present study emphasizes that distal ACA aneurysms tend to bleed, irrespective of their size, and that excellent outcomes are obtainable by direct surgery.