Search

Background: The main access route for middle cerebral artery (MCA) aneurysms is the transsylvian approach. Although Sylvian fissure (SF) variations have been assessed, none have examined how this affects MCA aneurysm surgery. The objective of this study is to investigate how SF variants affect clinical and radiological outcomes for surgically-treated unruptured MCA aneurysms., Methods: This retrospective study examined consecutive unruptured MCA aneurysms in 101 patients undergoing SF dissection and aneurysm clipping. SF anatomical variants were categorized using a novel functional anatomical classification: Type I: Wide straight, Type II: Wide with frontal and/or temporal opercula herniation, Type III: Narrow straight, and Type IV: Narrow with frontal and/or temporal opercula herniation. The relationships between SF variants and postoperative edema, ischemia, hemorrhage, vasospasm, and Glasgow Outcome Scale (GOS) were analyzed., Results: Study included 101 patients (53.5% women), 60.9 ± 9.4 (range 24-78) years. SF types were 29.7% Type I, 19.8% Type II, 35.6% Type III, and 14.9% Type IV. The SF type with the highest proportion of females was Type IV (n = 11, 73.3%), while it was Type III for males (n = 23, 63.9%) (P = 0.03). There were significant differences between SF types, ischemia, and edema (P < 0.001, P = 0.008, respectively). Although narrow SF types had poorer GOS scores (P = 0.055), there were no significant differences between SF types and GOS, postoperative hemorrhage, vasospasm, or hospital stay., Conclusions: Sylvian fissure variants may impact intraoperative complications during aneurysm surgery. Thus, presurgical determination of SF variants can predict surgical difficulties, thereby potentially reducing morbidity for patients with MCA aneurysms and other pathologies requiring SF dissection., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Poor-grade aneurysmal subarachnoid hemorrhage (PGASAH) is associated with high mortality and morbidity regardless of treatment. Herein, we re-evaluate the safety and efficacy of microsurgical treatment for managing PGASAH patients in the current endovascular era., Methods: We retrospectively reviewed 141 consecutive patient records in a single institution who underwent microsurgical (n = 80) or endovascular (n = 61) treatment for PGASAH., Results: Baseline characteristics were similar, except for more intracerebral hematomas (46.3% vs 24.6%, p = 0.009), fewer intraventricular hemorrhages (26.3% vs 59%, p < 0.001), and fewer posterior circulation aneurysms (5.1% vs 44.3%, p < 0.001) in the microsurgery group. Decompressive craniectomy (58.5% vs 24.6%, p < 0.001) and shunt-dependent hydrocephalus (63.7% vs 41%, p = 0.01) were more common for microsurgery, while procedural ischemic complications were less common (5% vs 24.6%, p = 0.001). Both early (12.5% vs 32.8%, p = 0.006) and late mortality rates (22.5% vs 39.3%, p = 0.041) were lower for microsurgery, and favorable 12-month outcomes (modified Rankin scale = 0-2) were better (62.5% vs 42.6%, p = 0.026). Multivariate analysis revealed that advanced age, neurological grade, modified Fisher grade, larger aneurysm size, rebleeding, and cerebral infarctions were independent predictors of poor outcome. Microsurgery fared marginally better than endovascular treatment (OR: 2.630, 95% CI: [0.991-6.981], p = 0.052)., Conclusions: Timely and efficient treatment, either via open microsurgery or endovascular surgery, provided favorable outcomes for over half of PGASAH patients in this series. Therefore, early treatment should be offered to all PGASAH patients regardless of clinical and/or radiological factors. Microsurgery remains an effective treatment modality for selected PGASAH patients in the endovascular era., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Posterior circulation aneurysms have a higher tendency to rupture and become symptomatic in comparison to anterior circulation aneurysms. Current treatment modalities for aneurysms in these locations vary widely including microsurgical clipping, trapping with bypass, wrapping, and various endovascular methods such as coiling, balloon or stent-assisted coiling, flow diversion, and vessel sacrifice, among others.Overall, surgical versus endovascular treatment of posterior circulation aneurysms continue to be a controversial topic in cerebrovascular neurosurgery. At our center, multi-disciplinary assessments including surgeons capable of both endovascular and microsurgical treatments of these aneurysms are employed to guide the treatment strategies. As advancements in both fields are made, this will continue to be a topic for debate. Anatomy and individual patient's characteristics will dictate the correct approach and therefore proficiency in the microsurgical techniques required to treat these aneurysms will continue to be both relevant and important., (© 2022. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Background: Determining if paraclinoid aneurysms are intradural or extradural is critical for surgical planning., Objective: To create an easily reproducible diagnostic method based on bony anatomy that precisely locates the distal dural ring (DDR) to determine the position of paraclinoid aneurysms as intradural, transitional, or extradural., Methods: Bilateral anatomic dissections of 10 cadaveric heads (20 sides) were performed to evaluate DDR anatomy. We observed a plane that reflects the position of the DDR passes through 4 bony landmarks: 1) The anterior clinoid-internal carotid artery intersection, 2) the optic strut, 3) the optico-carotid elevation, and 4) the base of the posterior clinoid process. This landmark-based plane can thus define the location of the DDR using 3-dimensional computed tomography angiography (CTA). This was confirmed in 27 surgical patients with intradural/transitional aneurysms and 7 patients with extradural aneurysms confirmed with magnetic resonance imaging (MRI). The DDR plane method easily classified aneurysm locations as intradural (above the DDR plane), extradural (below the DDR plane), or transitional (the DDR plane crosses the aneurysm). The aneurysm's location was subsequently confirmed intraoperatively or with MRI., Results: The DDR plane method determined if paraclinoid aneurysms were intradural, transitional, or extradural in all 34 cases examined. The visibility of the anatomic features that define the DDR plane was also verified in 82% to 89% of CTA images from 100 patients., Conclusion: The DDR plane method provides a useful diagnostic tool to evaluate the position of the DDR and determine the anatomic location of paraclinoid aneurysms., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Background: Cerebral bypass procedures are complex and require substantial experience and skills and thorough preoperative planning. Cerebrovascular surgeons face increasingly complex bypass cases because most routine cases are managed by endovascular means, and because increasing numbers of patients have complex medical problems that affect available and suitable bypass conduit options. We report the cases of several patients undergoing cerebral bypass with limited bypass conduit alternatives, in whom there were unexpected intraoperative difficulties requiring complex solutions., Methods: The neurological surgery department database was reviewed to identify patients who had undergone cerebral bypass procedures during a 13-year period in whom there were limited available bypass conduits, and in whom unexpected intraoperative difficulties were encountered during cerebral bypass., Results: Patient outcomes and graft patency were evaluated for 13 patients including 6 with ischemia, 3 with giant aneurysms, 2 with mycotic aneurysms, 1 with dissecting aneurysm, and 1 with gunshot-induced pseudoaneurysm. Median duration of follow-up was 43 months. In 12 of 13 patients, bypass graft/grafts were patent on the last computed tomography angiogram. In 1 patient, a prophylactic bypass procedure, the graft was not filling, probably because of lack of demand. Two patients died during follow-up of unrelated causes., Conclusions: Cerebrovascular surgeons should be versatile in dealing with patients with complex bypass. When there are limited available conduit options, we find that collaboration with other surgical specialties (e.g., plastics and vascular) is helpful. In patients in whom extreme intraoperative difficulties are expected, thorough preoperative planning with multiple backup plans should be exercised, as described in this report., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: It can sometimes be challenging to find a suitable clip to treat an unusual aneurysm, or when the surrounding anatomy is unusual, especially in resource-limited environments. We describe a method to modify aneurysm clips based on the method originated by Sugita et al in 1985. Herein clip modification (Clip-Mod) is used to treat anatomically difficult anterior communicating artery aneurysms., Methods: The Department of Neurological Surgery database was reviewed to find aneurysm patients treated using modified aneurysm clips. Clip-Mod was performed during surgery by shortening the tines of titanium aneurysm clips by abrasion applied from the side of a standard 3-mm surgical diamond drill bit under constant irrigation. Note that the thickness of the tines and the clip spring were not modified or contacted by the drill., Results: Four cases used modified aneurysm clips, from 648 total clip-treated aneurysms (0.6%) by 2 surgeons over a 14-year period. Three patients presented with subarachnoid hemorrhages that were determined to be due to anterior communicating artery aneurysms. One patient presented with an incidental unruptured anterior communicating artery aneurysm. All 4 patients were treated with 3-mm titanium clips shortened intraoperatively to 1- to 2-mm lengths, to achieve aneurysm obliteration without stenosing parent or perforating vessels., Conclusions: All 4 patients have done well clinically with no reoccurrences after 2-6 years' follow-up, which included angiographic evaluation. The use of this "Clip-Mod" technique thus appears useful for anterior communicating artery aneurysms. Clip-Mod could also be considered for treating other aneurysms when the "perfect" length clip is not available., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: In contemporary microneurosurgery reducing retraction-induced injury to the brain is essential. Self-retaining retractor systems are commonly used to improve visualization and decrease the repetitive microtrauma, but sometimes self-retaining retractor systems can be cumbersome and the force applied can cause focal ischemia or contusions. This may increase the morbidity and mortality. Here, we describe a technique of retraction using 10-0 sutures in the arachnoid., Objective: To evaluate the imaging and clinical results in patients where 10-0 suture retraction was used to aid the surgical procedure., Methods: Adjacent cortex was retracted by placing 10-0 nylon suture in the arachnoid of the bank or banks of the sulcus. The suture was secured to the adjacent dural edge by using aneurysm clips, allowing for easy adjustability of the amount of retraction. We retrospectively analyzed the neurological outcome, signal changes in postoperative imaging, and ease of performing surgery in 31 patients with various intracranial lesions including intracranial aneurysms, intra- and extra-axial tumors, and cerebral ischemia requiring arterial bypass., Results: Clinically, there were no injuries, vascular events, or neurological deficits referable to the relevant cortex. Postoperative imaging did not show changes consistent with ischemia or contusion due to the retraction. This technique improved the visualization and illumination of the surgical field in all cases., Conclusion: Retraction of the arachnoid can be used safely in cases where trans-sulcal dissection is required. This technique may improve initial visualization and decrease the need for dynamic or static retraction.

Giant posterior circulation aneurysms pose a significant challenge to neurovascular surgeons. Among various treatment methods that have been applied individually or in combination, clipping under hypothermic circulatory arrest (HCA) is rarely used. We present a 62-year-old man who initially underwent coil occlusion of the right vertebral artery (VA) for a 2.5 cm giant vertebrobasilar junction (VBJ) aneurysm. His neurological condition had declined gradually and the aneurysm grew to 4 cm in size. The patient underwent clip reconstruction of giant VBJ aneurysm under HCA. His postoperative course was prolonged due to his preexisting neurological deficits. His preoperative Modified Rankin Score was 5, and improved postoperatively to 3 at three and six months, and to 2 at one year. The video can be found here: http://youtu.be/L53SiLV8eJY.

Intracranial pseudoaneurysms (IP) represent about 1% of all patients presenting with an intracranial aneurysm. In true intracranial aneurysms, the intima, internal elastic lamina, and media are disrupted, but the adventitia is intact. In pseudoaneurysms, there is disruption of all three layers of the arterial wall, thus resulting in higher rates of re-hemorrhage and thrombus formation. Patients with IP commonly present with subarachnoid hemorrhage or thromboembolic complications. Until now, no specific guidelines have been established for the ideal treatment of pseudoaneurysms. Although IP have higher rates of morbidity and mortality compared to true intracranial aneurysms, surgical treatment can prevent catastrophic hemorrhagic and thrombotic complications. Despite recent advances in endovascular techniques that allow safe approaches to complicated intracranial vascular pathologies, vascular trapping and bypass remains the definitive and safe treatment for IP. Based on our experience and related literature, we consider the latter treatment in experienced hands as an effective and decisive treatment modality to prevent the devastating complications of IP. In this article, we discuss the surgical management of iatrogenic intracranial internal carotid artery pseudoaneurysms by trapping, and extracranial-intracranial bypass through a case illustration in which the technique is demonstrated via a video presentation.

Thrombosed giant intracranial aneurysms usually present with symptoms and signs from their mass effect. Although multiple treatment options are available, direct clip reconstruction with thromboendarterectomy remains the gold standard. Here we present a 66-year-old man with seizure, aphasia and hemiparesis. Work-up revealed a giant partially thrombosed aneurysm of the internal carotid artery bifurcation with surrounding vasogenic edema. He underwent clip reconstruction of the aneurysm via a cranio-orbital approach. Although we prepared for bypass with the radial artery and/or the superficial temporal artery, we were able to clip-reconstruct the aneurysm without bypass. The patient improved upon his pre-morbid state after surgery and made an excellent recovery. The video can be found here: http://youtu.be/P&#95;10hRQFuPo .

Object: The goal of this study was to determine whether drilling out the occipital condyle facilitates surgery via the far-lateral approach by comparing data from 10 clinical cases with that from studies of eight cadaver heads., Methods: During the last 6 years at Louisiana State University Health Sciences Center-Shreveport, 10 patients underwent surgery via the far-lateral approach to the foramen magnum. Six of these patients harbored anterior foramen magnum meningiomas, one patient a dermoid cyst, two patients vertebral artery (VA) aneurysms, and an additional patient suffered from rheumatoid disease of the craniocervical junction. The surgical approach consisted of retromastoid craniectomy and C-1 laminectomy. The seven tumors and the pannus of rheumatoid disease were completely excised, and the two aneurysms were clipped without drilling the occipital condyle. In one patient a chronic subdural hematoma was found 3 months after surgery, but no patient displayed any complication associated with surgery. It is significant that in no patient was a cerebrospinal fluid leak present. All patients experienced improved neurological function postoperatively. To compare surgical visibility, eight cadaveric specimens (16 sides) were studied, including delineation of the VA and its segments around the craniocervical junction. Increase in visibility as a function of fractional removal of the occipital condyle was quantified by measuring the degrees of visibility gained by removing one third and one half of the occipital condyle. Removal of one third of the occipital condyle produced a mean increase of 15.9 degrees visibility, and removal of one half produced a mean increase of 19.9 degrees., Conclusions: On the basis of their findings the authors conclude that removal of the occipital condyle is not necessary for the safe and complete resection of anterior intradural foramen magnum tumors.

The initial presentation of intracranial aneurysm can be missed in routine clinical practice. An underlying aneurysm may have a subtle presentation that warrants definitive diagnostic procedures. A retrospective review of 270 patients with aneurysms at our institution revealed 40 patients (14.8%) with a significant delay in diagnosis before definitive treatment. The delay due to missed diagnosis varied from 2 days to a few months. In retrospect, 58% had a Hunt and Hess grade I clinical presentation at readmission. Clinical status was rated as grade 0-I in the majority of patients (65%), grade II in 20%, and grade III in 12.5%. One patient had grade IV status. These grades are significantly different from the initial grade at which each of the patients first sought medical attention. The second admission significantly affected the outcome. A delay in diagnosis of aneurysmal subarachnoid hemorrhage resulting in poor clinical grade influenced neurologic outcome significantly.

We report a patient who presented with headache due to diffuse subarachnoid hemorrhage. A four-vessel angiogram revealed a left posterior communicating artery aneurysm with fetal origin, persistent primitive trigeminal artery and hypoplastic vertebral artery on the same side. This association was considered coincidental and co-existence of a saccular aneurysm with an anatomical variation of intracranial vasculature is briefly discussed.

Object: Transluminal angioplasty has become a widely used adjunct therapy to medical management of symptomatic cerebral vasospasm following subarachnoid hemorrhage (SAH). Despite anecdotal reports of universal, angiographically confirmed reversal of vasospasm and high rates of clinical improvement, no rigorous examination of the efficacy of this procedure has been conducted. In this study the authors assess the efficacy of the aforementioned procedure., Methods: Thirty-eight patients enrolled as part of the North American trial of tirilazad in aneurysmal SAH underwent transluminal angioplasty for symptomatic cerebral vasospasm. Fifty-three percent of these patients showed good recovery or moderate disability based on their 3-month Glasgow Outcome Scale score. Among the 38 patients who underwent angioplasty, the severity and type of vasospasm, use of papaverine in addition to balloon angioplasty, timing of treatment, and dose of study drug did not have an effect on the outcome. The results of their neurological examinations improved in only four of the 38 patients immediately after the procedure. A conditional logistic regression analysis was performed in which these patients were compared with individuals matched for age, sex, dose of study drug, admission neurological grade, and modified Glasgow Coma Scale score at the time of angioplasty. No effect on favorable outcomes was found for this procedure., Conclusions: Transluminal cerebral angioplasty is very effective in reversing angiographically confirmed vasospasm, and anecdotal reports of its clinical utility are numerous. However, in this report the authors conclude that its superiority to medical management for symptomatic cerebral vasospasm is questionable.

Objective: Associations among various factors and the occurrence of hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) were evaluated retrospectively in 897 patients enrolled in the North American study of tirilazad mesylate., Methods: Patients were assessed for hydrocephalus in a blinded fashion. Assessment of hydrocephalus was made on the basis of 3-month follow-up computed tomographic studies or, for those without a 3-month follow-up scan, on the basis of the latest computed tomographic studies obtained at least 10 days after SAH. Criteria indicating the occurrence of hydrocephalus were the presence of significantly enlarged temporal horns or prior placement of a ventricular shunt. Univariate analysis was performed to assess relationships among various factors and hydrocephalus. Factors statistically associated with the occurrence of hydrocephalus were analyzed further using logistic regression analysis., Results: Overall, 25.9% of the 897 patients developed hydrocephalus. Statistically significant associations among the following factors and hydrocephalus were observed (P value; risk coefficient): 1) severity of 3-month post-SAH Glasgow Outcome Scale (0.0001; 2.00); 2) increased ventricular size at admission (0.0001; 2.78); 3) neurological grade severity at admission (0.0274; 1.26); 4) preexisting hypertension (0.0284; 1.66); 5) alcoholism (0.0066; 2.30); 6) female sex (0.0056; 0.49); 7) increased aneurysm size (0.0239; 0.56); 8) pneumonia (0.0299; 1.78); 9) meningitis (0.0290; 5.86); and 10) intraventricular hemorrhage at admission (0.0414; 1.64)., Conclusion: Hydrocephalus seems to have a multifactorial etiology. Knowledge of risk factors related to the occurrence of hydrocephalus may help guide neurosurgeons in the long-term care of patients who have experienced aneurysmal SAH.

A 32-year-old male presented with subarachnoid hemorrhage following head trauma. Initial carotid angiography revealed an aneurysm protruding from the dorsal wall of the supraclinoid internal carotid artery. Two weeks later, following two additional hemorrhagic episodes, repeat carotid angiography showed severe vasospasm and dramatic expansion of the aneurysm. He died 17 days after the accident. Autopsy and histological examination confirmed the diagnosis of a traumatic, false aneurysm of the internal carotid artery. Improved prognosis requires early recognition and surgical obliteration of such aneurysms.