Basilar Artery Apex Research Articles

The effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization.

Arterial bifurcations are common locations for aneurysm development given the altered hemodynamic forces and shear stress variations present at these locations. Recent reports indicate that a wide basilar artery bifurcation angle is an independent predictor of aneurysm development, growth, and subsequent rupture. To determine the effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization, the records of 46 patients with basilar artery apex aneurysms treated with endovascular coil embolization from 2007 to 2013 were analyzed. A wide basilar artery bifurcation angle was associated with a Raymond-Roy Occlusion Classification (RROC) III occlusion in univariate analysis, but was not a statistically significant factor in multivariate modeling. An increasing basilar artery bifurcation angle was not associated with aneurysm recanalization or retreatment following coil embolization. Increasing packing density (p < .01) was the only statistically significant predictor of a RROC I or II closure. The initial RROC designation was the most powerful predictor of both eventual aneurysm recanalization (p = .01) and retreatment (p = .02). While increasing aneurysm size (p < .01), increasing aneurysm volume (p < .01), and increasing neck size (p < .01) were associated with wide basilar artery bifurcation angles, neck size (p = .03) was the only statistically significant predictor of basilar artery bifurcation angle on multivariate analyses. Basilar artery bifurcation angle fails to predict rates of initial occlusion, recanalization, and retreatment on multivariate modeling in our series. Basilar artery apex aneurysm neck size independently correlates with basilar artery bifurcation angle.

The Art of Basilar Apex Aneurysm Surgery: Is It Sustainable in the Future?

There has been a massive shift in the balance toward endovascular therapy for basilar artery (BA) aneurysms in the modern era.We retrospectively reviewed clinical and radiologic data from patients with BA aneurysms who were treated in a single medical center during a 10-year period from August 2006 to May 2016.Thirty-five consecutive patients with 46 aneurysms during the 10-year period were included. The rate of complete aneurysm occlusion in 35 cases using a 1-stage operation was 58.8% (20/34). The graft patency rates of 13 bypass surgeries were 84.6% (11/13) within 1 week and 69.2% (9/13) at 3 months after surgery. The cut flow index for all bypass cases was 0.79. The overall survival was 94% at discharge (2 patients died). The 3-month outcome was favorable (modified Rankin Scale score 0–2) for 27 patients (77.1%) and poor (modified Rankin Scale score 3–5) for 5 patients (14.2%), and 3 patients died (8.6%). The survival for patients with BA apex aneurysms was higher than the survival observed for patients with BA trunk/vertebrobasilar junction aneurysms.Microsurgical treatments for BA aneurysms can be effective, with good patient outcomes in the early stage after operation. Patients with wide-necked, fusiform, or dolichoectatic aneurysms seem to exclude the aneurysm, preventing unnecessary retreatments with bypass techniques. The potential for a poor prognosis of patients with BA trunk/vertebrobasilar junction aneurysms was higher than that for patients with basilar apex aneurysms who presented with unfavorable subsequent events.

Microsurgical Management of Basilar Artery Apex Aneurysms

asilar artery apex aneurysm is a critical nervous system vascular disease and accounts for 5% of central nervous B system aneurysms. With improvements in clinical diagnosis and the application of digital subtraction angiography, increasing numbers of basilar artery apex aneurysms are being diagnosed, and the choice of surgical treatment versus conservative observation becomes a concern. Nanda et al. present their experience with consecutively operated complex basilar apex aneurysms. Concerning the management of large or giant, wideneck, and calcified or thrombosed aneurysms, the authors conclude that microneurosurgery is still a useful alternative to endovascular therapy.

At the Apex of Cerebrovascular Surgery—Basilar Tip Aneurysms

nruptured vertebrobasilar aneurysms account at least for 5% of all intracranial aneurysms (3), and basilar U artery apex aneurysms account for 50% of vertebrobasilar aneurysms (1). In Helsinki, 16% of hospitalized patients have posterior circulation aneurysms on computed tomography angiography. Basilar bifurcation aneurysms have often been rated as the most difficult of all intracranial aneurysms to be treated by surgery. As stated by Drake et al. (1), only 12 reported cases of operated basilar artery aneurysms were published in literature by 1960, whereas roughly 350 intracranial operations for anterior circulation aneurysms were reported by that time. In 1954, Olivecrona was the first neurosurgeon to clip a basilar artery apex aneurysm successfully (1). In 1984, Yasargil (4) reported the results of his series of 50 patients with basilar artery apex aneurysms (96% had a subarachnoid hemorrhage); he reported a “good” neurologic outcome in 37 (76%) of 50 patients. Subarachnoid hemorrhage itself most likely contributed to poor outcome in some patients. In 1985, Sugita and Kobayashi (2) reported their results of 49 patients with basilar artery apex aneurysms; they reported a good or excellent outcome in 40 (82%) of 49 patients. Most of these patients also had a subarachnoid hemorrhage, similar to the series by Drake et al. (1). The series by Drake et al. was published in 1996 and reported good or excellent results in 669 (86.9%) of 770 patients with clipped basilar bifurcation aneurysms. Microsurgical clipping resulted in a good or excellent outcome in 425 (90.6%) of 469 patients with small basilar tip aneurysms, 205 (84.4%) of 243 patients with large aneurysms, and 39 (67.2%) of 58 patients with giant basilar artery apex aneurysms (1). Despite notable improvements in cerebrovascular imaging, neuroanesthesia, and

Endovascular therapy for posterior circulation aneurysms: report with 14 cases

Objective To investingate the safety and feasibility of endovascular therapy in posterior circulation aneurysms.Methods There were 14 patients with posterior circulation aneurysms in this group,8 aneurysms located in the apex of basilar artery,3 aneurysms in superior cerebellar artery,l aneruysms in posterior inferior cerebellar artery,2 dissect aneurysms in vertebral artery. 6 patients were treated with coiling,3 patients with balloon assisted coiling,4 patients with Neuroform stent assisted coiling,1 patient was with Neuroform stent. Results 11 patients received complete occlusion,3 patients receiced 95％ occlusion.There was no SAH within follow - up period. DSA was performed in 3 patients,there was no recurrence. The patient solo -treated with stent was followed up with DSA one month later,and the aneurysm disappeared.Conclusion Endovascular therapy is a valuable and safe method for treatment of posterior circulation aneurysms. Key words: Intracranial aneurysm; Posterior circulation aneurysm; Endovascular therapy

Angiographic features of “brain sag”

Cerebrospinal fluid hypotension, or "brain sag," is a recently described phenomenon most commonly seen following craniotomy for the clipping of ruptured aneurysms along with preoperative lumbar drain placement. The clinical features and CT findings have been previously described. Clinical presentation can be similar to and often mistaken for cerebral vasospasm. In this study, the authors report on the angiographic findings in patients with brain sag. Five cases of brain sag were diagnosed (range 1-4 days) after the surgical treatment of ruptured aneurysms at the University of Illinois at Chicago. All patients met the clinical and CT criteria for brain sag. Admission cerebral angiograms and subsequent angiograms during symptoms of brain sag were obtained in all patients. In 3 patients, angiography was performed after the resolution of symptoms. In all 5 patients, the level of the basilar artery apex was displaced inferiorly with respect to the posterior clinoid processes during brain sag. This displacement was significant enough to create a noticeable kink in the basilar artery ("cobra sign") in 3 patients. Other angiographic findings included foreshortening or kinking of the intracranial vertebral artery. In all patients, the posterior cerebral arteries were displaced medially and inferiorly. Three patients were treated for simultaneous severe radiological vasospasm. In 4 patients, the brain sag was recognized, and the patients' conditions improved when they were placed flat or in the Trendelenburg position, at times combined with an epidural blood patch. Patients with follow-up angiography studies after the symptoms had resolved displayed a reversal of the angiographic features. Brain sag appears to be associated with characteristic angiographic features. Recognizing these features may help to diagnose brain sag as the cause of neurological deterioration in this patient population.

Complex basilar artery aneurysms treated using surgical basilar occlusion: a modern case series

Complex aneurysms of the basilar artery (BA) apex can be successfully treated using surgical occlusion of the proximal BA. Since the introduction of the Guglielmi detachable coil in 1991, the focus on treating BA aneurysms has been on using endovascular techniques. Outcomes with endovascular techniques have been less than optimal for large and complex aneurysms. The authors therefore report on their current 22-year experience with surgical BA occlusion for complex BA aneurysms and long-term outcome. Fifteen patients underwent surgical BA occlusion at Columbia University Medical Center for complex basilar apex aneurysms between 1987 and 2009. The clinical records of each patient were reviewed for details of presentation, hospital course, operative intervention, and outcome. Postoperatively, all patient encounters were recorded at discharge, at the 1-month and 1-year follow-up evaluations, and at long-term outcome. Twelve (80%) of 15 patients experienced no new postoperative neurological deficits. Three patients presenting with severe neurological impairment (modified Rankin Scale [mRS] score > 3) made excellent recoveries (mRS Scores 1-2) at long-term follow-up. One patient died, 1 suffered a stroke during the postoperative angiogram which resulted in hemiparesis, and 1 suffered internuclear ophthalmoplegia which resolved by the 1-month follow-up. Long-term follow-up occurred at an average of 3 ± 4.5 years, ranging from 2 months (for a recently treated patient) to 18 years. The average mRS score at long-term follow-up was 1 ± 1.5. No patient experienced postoperative hemorrhage, rebleeding, or delayed neurological deterioration. Surgical occlusion of the BA is an effective treatment option offering a high rate of angiographic cure in a single procedure for patients with complex BA aneurysms. The ability to surgically perform point occlusion of the BA without impairment of brainstem perforators, while maintaining collateral blood flow to the posterior circulation branch vessels, may provide an advantage compared with endovascular treatments.

Accessing the Basilar Artery Apex: Is the Temporopolar Transcavernous Route an Anatomically Advantageous Alternative?

The restricted operative field, difficulty of obtaining proximal vascular control, and close relationship to important anatomic structures limit approaches to basilar apex aneurysms. We used a cadaveric model to compare three surgical transcavernous routes to the basilar apex in the neutral configuration. Five cadaveric heads were dissected and analyzed. Working areas and length of exposure provided by the transcavernous (TC) approach via pterional, orbitozygomatic, and temporopolar (TP) routes were measured along with assessment of anatomic variation for the basilar apex region. In the pterional TC and orbitozygomatic TC approaches, the mean length of exposure of the basilar artery measured 6.9 and 7.2 mm, respectively (p = NS). The mean length of exposure in a TP TC approach increased to 9.3 mm (p < 0.05). Compared with the pterional and orbitozygomatic approaches, the TP TC approach provided a larger peribasilar area of exposure ipsilaterally and contralaterally (p < 0.05). The multiplanar working area related to the TP TC approach was 77.7 and 69.5% wider than for the pterional TC and orbitozygomatic TC, respectively. For a basilar apex in the neutral position, the TP TC approach may be advantageous, providing a wider working area for the basilar apex region, improving maneuverability for clip application, fine visualization of perforators, and better proximal control.

Endovascular therapy of posterior circulation aneurysms

Objective To investigate the safety and feasibility of endovascular therapy in posterior circulation aneurysms. Method There were 47 patients with posterior circulation aneurysms in this group, 25 aneurysms located in the apex of basilar artery,4 aneurysms in superior cerebellar artery,5 aneurysms in posterior inferior cerebellar artery,2 aneurysms in anterior inferior cerebellar artery,9 dissect aneurysms in vertebral artery,other 2 patients suffered from multiple aneurysms. 23 patients were treated with coiling, 16 patients with balloon assisted coiling, 7 patients with Neuroform stent assisted coiling, 1 patient was with Neuroform stent. Results 37 patients received complete occlusion,9 patients received 95% occlusion. 1 patient combined with Moyamoya disease died of widespread brain swelling and cerebral hernia after the procedure. There was no SAH within follow-up period. DSA was performed in 5 patients, there was no recurrence. The patient solo-treated with stent was followed up with DSA one month later,and the aneurysm disappeared. Conclusions Endovascular therapy is a valuable and safe method for treatment of posterior circulation aneurysms, balloon remodeling and stent assistant embolization should be performed in wide-necked aneurysms. Key words: Intracranial aneurysm; Posterior circulation; Endovascular therapy

Upper basilar artery aneurysms: oculomotor outcomes in 163 cases

The purpose of this study was to identify factors predictive of postoperative oculomotor nerve palsy among patients who undergo surgery for distal basilar artery (BA) aneurysms. The data can be used to estimate preoperative risk in this population. The natural history of oculomotor nerve palsy in patients with good outcomes is also defined. The cases of 163 patients with distal BA aneurysms, who were treated surgically between 1996 and 2002, were retrospectively studied to identify factors contributing to oculomotor nerve palsy. After the data had been collected, stepwise logistic regression procedures were used to determine the predictive effects of each variable on the development of oculomotor nerve palsy and to create a scoring system. Factors that interfered with resolution of oculomotor dysfunction in patients with good outcomes were also studied. Postoperative oculomotor nerve palsy occurred in 86 patients (52.8%) with distal BA aneurysms. The following factors were associated with postoperative oculomotor dysfunction, as determined by a categorical data analysis: (1) younger patient age (p < 0.001); (2) poor admission Hunt and Hess grade (p < 0.001); (3) use of temporary arterial occlusion (p < 0.001); 4) poor Glasgow Outcome Scale score (p < 0.001); and (5) the presence of a BA apex aneurysm that projected posteriorly (p < 0.001). For patients with good outcomes, postoperative oculomotor nerve palsy resolved completely within 3 months in 31 patients (52%) and within 6 months in 47 patients (80%). The projection of the BA aneurysm was associated with incomplete oculomotor recovery at 6 months postoperatively (p = 0.019). The results of this study can help identify patients with a high risk for the development of oculomotor nerve palsy. This may help neurosurgeons in preoperative planning and discussions.

Basilar artery to bilateral posterior cerebral artery 'Y stenting' for endovascular reconstruction of wide-necked basilar apex aneurysms: report of three cases

Endovascular reconstruction of basilar artery (BA) apex aneurysms has been augmented by adjunctive techniques such as balloon and stent assistance. We present three cases of a wide-necked BA apex aneurysm involving the bilateral P1 segments of both posterior cerebral arteries (PCAs) treated by placement of BA to PCA stents bilaterally in a 'Y' configuration to reconstruct the BA apex for effective coil embolization. Three patients (aged 70, 65 and 37 years) with wide-necked basilar artery aneurysms presented for endovascular treatment. All aneurysms had necks that involved the bilateral P1 segments. Each patient was deemed an appropriate candidate for endovascular reconstruction. Patients were pretreated with clopidogrel (75 mg) and aspirin (325 mg) each day for 3 days prior to the procedure. Following induction of general anesthesia, access to the right femoral artery was obtained by placement of a 6F sheath. Intravenous heparin was administered to achieve an activated coagulation time (ACT) of approximately 300 seconds. A 6F guide catheter was placed within the left vertebral artery (VA) in two patients, the right VA in a third. Utilizing over-the-wire (OTW) technique, a microcatheter was advanced into the left P2-P3 junction of the PCA. A 300-cm 0.014-inch microwire was passed through the microcatheter into the distal PCA and the microcatheter was removed. In each case, two neuroform stents were prepared (SMART Therapeutics Inc., San Leandro, CA) and advanced OTW into the PCA with the most acute angle relative to the BA. The initial stent placed was 20 mm in length and was deployed from the P1 segment into the BA. The microwire was pulled retrograde into the BA apex, then advanced though the stent struts and into the right PCA. A second stent, 15mm in length, was advanced OTW through the struts of the previously placed stent. It was then deployed from the P1 into the BA where it overlapped the first stent, resulting in a stent-in-stent 'Y' configuration at the BA apex. A microcatheter was advanced OTW into the BA apex aneurysm and coil embolization proceeded in the usual fashion. Following the procedure, each patient was maintained in the neurosurgical intensive care unit (NICU). All remained neurologically intact. The two elderly patients were discharged to home the morning following the procedure. The third patient suffered an upper GI bleed and was treated an additional 3 days in hospital. Oral clopidogrel (75 mg by mouth) and aspirin (325 mg by mouth) were continued daily for 4 weeks. The 'Y' stent configuration for reconstruction of the BA apex is a safe effective technique in patients with wide-necked BA aneurysms.

Endovascular Versus Surgical Treatment of Basilar Artery Apex Aneurysms

Endovascular Guglielmi detachable coil (GDC) occlusion, a relatively recent addition to the therapeutic armamentarium available for basilar artery apex aneurysms, continues to gain acceptance as a viable alternative to conventional microneurosurgical clipping. Two retrospective studies describe experience with this device. Gruber and colleages compared short-term outcomes for clip versus GDC in a cohort of 41 patients. Twenty-one patients were treated with GDC, …

Endoscope-assisted Supraorbital Craniotomy for Lesions of the Interpeduncular Fossa

The supraorbital approach is well accepted for lesions in the anterior fossa, the sellar region, and the anterior circle of Willis. However, the usefulness of this approach has not yet been elucidated for lesions in the interpeduncular fossa. The technique of an endoscope-assisted, ipsi- and contralateral supraorbital approach to lesions within the interpeduncular fossa is described, and the initial results are reported. A small supraorbital craniotomy, using an eyebrow incision, was performed in each of seven patients who were operated on for different types of lesions in the interpeduncular fossa, including a neuromuscular choristoma of the oculomotor nerve, a retrosellar epidermoid tumor, and five aneurysms (two of the basilar artery tip, two at the offspring of the superior cerebellar artery, and one fusiform arterial widening of the basilar artery apex). The surgical approach, its indications and limitations, and the additional value of an endoscope are outlined. All lesions could be easily reached and well visualized through this approach by using an endoscope as an adjunct to the operating microscope. The saccular aneurysms all could be clipped successfully, the fusiform widening was wrapped, the epidermoid tumor was removed completely, and the choristoma was removed only partially because of brain stem invasion. The patient with the neuromuscular choristoma had persistent diabetes insipidus postoperatively, most probably caused by stretching the pituitary stalk with the endoscope. The patient with the epidermoid tumor showed a postoperative transient partial oculomotor nerve paresis at the side of the approach. The cosmetic results of the eyebrow incisions for this approach were excellent in all patients. Lesions in the interpeduncular fossa can be effectively treated using a supraorbital approach, which can be ipsi- or contralateral to the side of the lesion, depending on the exact location of the lesion. The use of an endoscope is essential to visualize these lesions that lie in the shadow of the sellar and parasellar anatomic structures. The major advantage over other approaches are a nearly perpendicular surgical route (although the distance is longer, which is, on the other hand, not a disadvantage), a minimized amount of dissection and brain retraction by using an endoscope through anatomic gateways, and a small surgical incision with excellent cosmetic results.

Complex partial seizures associated with unruptured thrombosed basilar artery apex aneurysm

Complex partial seizures, an unusual presentation of a thrombosed basilar artery apex aneurysm, are described. The possible etiologies causing this presentation are reviewed.

Ligation of the basilar artery as the definitive treatment for a giant aneurysm of the basilar artery apex

Ligation of the basilar artery as the definitive treatment for a giant aneurysm of the basilar artery apex