Yasser Orz

Risks of surgery for patients with unruptured intracranial aneurysms

BACKGROUND With the widespread use of less invasive imaging tools, such as magnetic resonance angiography and computed tomographic angiography, unruptured cerebral aneurysms are found much more often than in the past. This retrospective study was undertaken to determine the risk factors for surgical intervention in a patient with an unruptured intracranial aneurysm. METHODS Over a 5-year period, 1,558 patients with intracranial aneurysms underwent surgery at our center. Of these, 310 patients (20%) with unruptured aneurysms were included in this study. RESULTS Out of 310 patients with unruptured aneurysms, 292 (95%) had a favorable outcome, and only one patient (0.3%) with a giant vertebral artery aneurysm died. Aneurysm size larger than 15 mm and location of the aneurysm in the posterior circulation were independent risk factors associated with less favorable outcomes. Patients with a single aneurysm had a better outcome than did patients with multiple aneurysms. CONCLUSION Our results support the contention that surgical treatment of unruptured intracranial aneurysms carries a low risk of morbidity and mortality and may improve the outcome in patients harboring cerebral aneurysms by preventing the devastating effects of subarachnoid hemorrhage. Aneurysm size, location, and number were risk predictors for surgical morbidity in patients with unruptured aneurysms.

Parameters for contralateral approach to ophthalmic segment aneurysms of the internal carotid artery.

OBJECTIVEThis study was undertaken to define more accurately the feasibility and indications of the contralateral pterional approach to ophthalmic segment aneurysms of the internal carotid artery (ICA). METHODSBetween 1995 and 1999, 46 patients with ophthalmic segment aneurysms of the ICA were surgically treated in our institution. Eleven of the 46 aneurysms were operated using the contralateral pterional approach. All aneurysms were successfully clipped without complications; three patients required bone resection around the aneurysm neck. We studied the 11 patients who were treated with the contralateral approach by defining six parameters to assess the feasibility of the approach and to predict the necessity for bone resection: 1) Parameter A, the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale; 2) Parameter B, the distance between the bilateral optic nerves at the entrance to the optic canal; 3) Parameter C, the interrelation of the optic nerve and the ICA, expressed as a/b in which a is the length from the midline to the optic nerve and b is the length from the midline to the ICA; 4) Parameter D, the size of the aneurysm neck; 5) Parameter E, the direction of the aneurysm from the ICA wall on the anteroposterior angiogram; and 6) Parameter F, the distance from the medial side of the estimated distal dural ring to the proximal aneurysm neck on the lateral angiogram. RESULTSParameters A to F were 8.8 mm (range, 5.4–11.1 mm), 14.5 mm (range, 10.4–22.2 mm), 0.9 mm (range, 0.6–1.3 mm), and 3.0 mm (range, 2.3–4.7 mm), 5 to 160 degrees, and 1.3 mm (range, 0.3–2.4 mm), respectively. All patients had excellent operative outcomes without visual dysfunction. Three patients required drilling of the bone around the optic canal on the craniotomy side; bone drilling was not required when Parameter E was between 30 and 160 degrees and Parameter F was more than 1 mm. CONCLUSIONParameters A to D are important for assessing the feasibility of the contralateral approach to ICA-ophthalmic segment aneurysms, and Parameters E and F are most useful for calculating the difficulty of this approach.

Surgical outcome for multiple intracranial aneurysms

SummaryThe surgical outcome of 221 cases with multiple intracranial aneurysms operated upon during the years 1988 to 1994 were reviewed. The patients were classified into three groups according to the locations of the aneurysms; group 1: multiple aneurysms located unilaterally in the anterior circulation only (147 cases); group 2: multiple aneurysms located bilaterally in the anterior circulation only (44 cases) and group 3: multiple aneurysms located in both anterior and posterior circulation or in the posterior circulation alone (30 cases). In 132 cases of group 1 (89.8%) all aneurysms were treated in one-stage operations. Twenty-eight patients from group 2 (63.6%) received partial treatment, where only the ruptured or the symptomatic aneurysms were treated. In 12 other cases from group 2 (27.3%) all multiple aneurysms were treated in two-stage operations. In group 3 patients, one-stage operations were performed in 18 cases (60%), while 9 patients (30%) received partial treatment only. Of the 221 multiple aneurysm cases, 162 (73.3%) presented with manifestations of subarachnoid haemorrhage (SAH). The remaining 59 multiple aneurysms cases (26.7%) presented with manifestations other than SAH (unruptured aneurysms). In the postoperative follow-up, of the 221 multiple aneurysms cases, 113 (51.1%) were free of neurological deficit (excellent), 48 cases (21.7%) were capable of leading an independent life (good), 32 cases (14.5%) were not independent and needed to be assisted (fair), and 28 patients (12.7%) died. These results were comparable to the results of patients with single aneurysms operated on during the same period.Based on our results, we recommend that whenever possible all multiple aneurysms should be treated in one-stage operations. In unruptured multiple aneurysm cases surgical management is the recommended treatment. In poor grade SAH patients or unruptured multiple aneurysms in old patients, two-stage operations or partial treatment of only the ruptured or the symptomatic aneurysms may be adopted.

Endovascular treatment of basilar trunk aneurysm associated with fenestration of the basilar artery

Abstract Basilar trunk saccular aneurysms associated with fenestration are infrequent, especially in the middle or distal portion of the basilar artery. Surgical treatment of the basilar trunk aneurysm is difficult, due to its anatomical environment and the complicated surgical exposure. A 46-year-old woman presenting with Hunt and Kosnik grade II subarachnoid hemorrhage was found to have a ruptured aneurysm arising at the proximal corner of the associated fenestration in the middle portion of the basilar artery. Because of surgical difficulties anticipated in approaching the aneurysm, it was decided to treat it with endovascular embolization utilizing the Guglielmi detachable coil; and complete occlusion of the aneurysm was obtained. The efficacy of endovascular treatment for the basilar trunk aneurysm with associated fenestration is discussed from anatomical and embryological points of view, and relevant literature is reviewed.

Transradial approach for selective cerebral angiography: technical note.

Abstract Selective cerebral angiography is currently being performed using transfemoral and transbrachial approaches. However, these techniques require patients to tolerate a prolonged focal compression and sometimes cause serious complications such as pulmonary embolism. The authors describe a technique of transradial approach as a safer selective cerebral angiography. Between July 1997 and November 1998, 70 patients underwent selective cerebral angiography with a transradial approach using a 4-F catheter. The collateral blood supply to the hand from the ulnar artery was confirmed using Allen’s test prior to the procedure. To prevent the mechanical spasm of the radial artery, an arterial introducer 20 cm long was used. The radial artery was successfully punctured and cannulated in all patients. Selective catheterization of the intended vessels was obtained In over 98% of the carotid angiography and over 95% of the vertebral angiography. No major vascular complications such as cerebral infarction, upper limb ischemia, significant local hematoma or pseudoaneurysm were experienced. The transradial approach is a less invasive and safer technique for selective cerebral angiography, and could be an alternative to transfemoral and transbrachial approaches. [Neurol Res 2000; 22: 605-608]

Specific characteristics and management strategies of posterior cerebral artery aneurysms:report of eleven cases

Owing to the deep location of the posterior cerebral artery (PCA) and its close relationship with the brainstem and surrounding vital structures, surgical treatment of aneurysms in this region is complex. This study was undertaken in an attempt to better delineate the surgical risks of PCA aneurysms. A retrospective analysis was undertaken in 11 patients with PCA aneurysm surgically treated between 1988 and 1996 at Shinshu University and its affiliated hospitals. Data regarding surgical strategy, surgical complications and outcomes were analysed. Seven aneurysms were saccular (including one mycotic) and the other four were fusiform, dissecting, thrombosed and an infundibular dilatation. The locations of the aneurysms were at the P1 segment in two patients, P1-P2 junction in two, P2 segment in six and P3 segment in one. Six saccular non-mycotic aneurysms were treated with neck clipping and the other five aneurysms were treated each with proximal occlusion of the parent artery, excision of the aneurysm or wrapping. All aneurysms were satisfactorily exposed except one large saccular aneurysm. Surgical outcomes were either good recovery or moderate disability in 10 patients, and severe disability in one patient with a large aneurysm due to temporal lobe contusion. In conclusion it is the responsibility of the surgeon dealing with rare PCA aneurysms to be aware of these specific characteristics and to appreciate which surgical technique is appropriate for each patient.

Juxta-dural ring aneurysms of the internal carotid artery

The terminology of juxta-dural ring aneurysms of the internal carotid artery is reviewed historically with special reference to those aneurysms protruding ventrally. The first description of such cases was made by Drake as exceptional examples of carotid-opthalmic aneurysms. Yasargil and Fox termed them ventral (inferior) internal carotid artery aneurysms. The term (ventral) paraclinoid aneurysms was coined by Nutik. We introduce the concept of carotid cave aneurysms. The name superior hypophyseal artery aneurysms was proposed by Day. Other related terminologies by various authors are also described.

No evidence of existence of functional 5-HT1 receptors in isolated and perfused canine basilar arteries

The vascular responses to intraluminally administered 5-hydroxytryptamine (5-HT), 5-carboxamidotryptamine (5-CT, a 5-HT(1)-like receptor agonist), alpha-methyl-5-hydroxytryptamine (alpha-M-5-HT, a 5-HT(2) receptor agonist) were examined, compared with those to noradrenaline (NA) and potassium chloride (KCl), in isolated and perfused canine basilar arteries using the steel cannula insertion method. These agonists usually elicited only a vasoconstriction in a dose related manner. Even in preconstricted preparations by 30 and 60 mM K(+) in modified Krebs solution, the injection of either 5-HT or 5-CT induced only monophasic constrictor responses without any dilation. The rank order of vasoconstrictive potency was 5-HT > alpha-M-5-HT >/= CT NA KCl. The constrictions to 5-HT, 5-CT and alpha-M-5-HT were significantly inhibited by ketanserin (a 5-HT(2) receptor antagonist), but not significantly blocked by methiothepin (a 5-HT(1) receptor antagonist). From these results, we concluded that 1) 5-HT induces a prominent vasoconstriction mainly due to an activation of 5-HT(2) receptors, 2) 5-CT-induced constriction may be mostly mediated by 5-HT(2) but not 5-HT(1) receptors, and 3) there are no functional vasodilator 5-HT receptors in the canine basilar artery.