Hasan Kocaeli

Use of radial artery grafts in extracranial–intracranial revascularization procedures

Cerebral revascularization procedures have been used in the clinical management of actual or threatened cerebral ischemic states and unclippable cerebral aneurysms. An alternative to a low-flow bypass graft (for example, with the superficial temporal artery) is the use of high-flow grafts created using the saphenous vein (SV) or radial artery (RA). These high-flow grafts are particularly useful when otherwise adequate collateral flow is insufficient to enable sacrifice of the parent vessel without the risk of cerebral ischemia. In their clinical series of 13 patients who underwent high-flow bypass with an RA graft, the authors describe 8 women and 5 men whose ages ranged from 44 to 69 years (mean 57.84 +/- 9.05 years). Indications for RA graft bypass were unclippable aneurysms in 10 patients and occlusive cerebrovascular disease in 3 patients. The authors review the properties of the 2 most common conduits, the SV and RA grafts. They present the technique of high-flow extracranial-intracranial bypass produced using RA grafts in the management of occlusive atherosclerotic disease and complex intracranial aneurysms that are not otherwise amenable to either clip ligation or coil occlusion.

Spontaneous Intradural Vertebral Artery Dissection: A Single-Center Experience and Review of the Literature

OBJECTIVES To define the natural history of spontaneous intracranial vertebral artery dissections (VADs) and to review current treatment strategies. MATERIAL AND METHODS We searched the MEDLINE database for all existing English and French literature on VADs through January 2008. Keywords employed were intradural/intracranial vertebral artery dissection, vertebral artery dissection, and vertebral artery dissection treatment. We also reviewed our series of patients with spontaneous VAD treated in the past 5 years. Data were collected, categorized, and analyzed. RESULTS In our sample of 457 patients, men were more frequently affected than women, and the mean age was 51.8 years. The majority of patients (79%) presented with subarachnoid hemorrhage (SAH). We experienced a high incidence (37%) of recurrent SAH, particularly within the first 24 hours after SAH first occurred. Angiographic fusiform dilatation and pearl-and-string lesions were the most common finding. Patients who presented with SAH fared worse than those who presented with ischemia. CONCLUSIONS Due to a high rate of recurrent bleeding, we concluded that early treatment by either surgical or endovascular route is indicated in patients who present with SAH secondary to spontaneous intradural VADs. Treatment decisions should take into account the site and type of dissection, vertebral artery dominance, and involvement of posterior inferior cerebellar artery.

The potential applications of high-intensity focused ultrasound (HIFU) in vascular neurosurgery.

This review assesses the feasibilty of high-intensity focused ultrasound (HIFU) in neurosurgical applications, specifically occlusion of intact blood vessels. Fourteen articles were examined. In summary, MRI was effective for HIFU guidance whereas MR angiography assessed vessel occlusion. Several studies noted immediate occlusion of blood vessels with HIFU. Long-term data, though scarce, indicated a trend of vessel recanalization and return to pre-treatment diameters. Effective parameters for extracranial vascular occlusion included intensity ranges of 1,690-8,800 W/cm(2), duration <15 seconds, and 0.68-3.3 MHz frequency. A threshold frequency-intensity product of 8,250 MHzW/cm(2) was needed for vascular occlusion with a sensitivity of 70% and a specificity of 86%. Complications include skin burns, hemorrhage, and damage to surrounding structures. With evidence that HIFU can successfully occlude extracranial blood vessels, refinement in applications and demonstrable intracranial occlusion are needed.

CDP-choline and its endogenous metabolites, cytidine and choline, promote the nerve regeneration and improve the functional recovery of injured rat sciatic nerves

Abstract Objective: Topical cytidine-5′-diphosphocholine (CDP-choline) has been shown to improve the functional recovery and promote the nerve regeneration of injured sciatic nerves in rats. The aims of this study were to test whether CDP-choline was effective at promoting nerve healing when the surgery to repair an injury was delayed and to determine whether the cytidine and/or the choline moieties of CDP-choline contribute to its beneficial actions. Methods: One hundred and fifty Sprague-Dawley rats underwent a surgical procedure that involved damaging the right sciatic nerve and suturing the epineurium. The injured sciatic nerve was either repaired immediately (on the first day) or on the third day after surgery. Rats were assigned to one of five groups and received a topical application of either 0·4 ml of saline (control) or 0·4 ml of 100 μM CDP-choline, cytidine, choline, or cytidine+choline. Results: The sciatic function index (SFI) of the rats in both groups (those who had their nerve repair immediately versus those on day 3) improved gradually by 4, 8, and 12 weeks after surgery. The percentage recovery in SFI score was significantly higher in rats treated with CDP-choline or cytidine+choline at all time points. Axon count increased by ∼50% in rats treated either with CDP-choline or cytidine+choline. Treatment with CDP-choline or cytidine+choline reduced scar formation and decreased nerve adherence when the sciatic nerve was repaired immediately, and rats treated with CDP-choline or cytidine+choline had better axonal organization than control rats. Treatment with choline or cytidine alone led to a less marked improvement in SFI score and failed to increase axon count. Conclusion: Our results demonstrate that CDP-choline, as well as the combination of its metabolites, cytidine+choline, improves the functional recovery and promotes the regeneration of injured sciatic nerves treated with immediate or delayed surgical repair in rats.

Anatomic variation of the optic strut: classification schema, radiologic evaluation, and surgical relevance.

Objective Anatomic variability of the optic strut in location, orientation, and dimensions is relevant in approaching ophthalmic artery aneurysms and tumors of the anterior cavernous sinus, medial sphenoid wing, and optic canal. Methods In 84 dry human skulls, imaging studies were performed (64-slice computed tomography [CT] scanner, axial view, aligned with the zygomatic arch). Optic strut location related to the prechiasmatic sulcus was classified as presulcal, sulcal, postsulcal, and asymmetric. Morphometric analysis was performed. Results The optic strut was presulcal in 11.9% specimens (posteromedial margin bilaterally anterior to limbus sphenoidale), sulcal in 44% (posteromedial part adjacent to the sulcuss anterior two thirds bilaterally), postsulcal in 29.8% (posteromedial margin posterior to the sulcuss anterior two thirds), and asymmetric (left/right) in 14.3%. Optic strut length, width, and thickness measured 6.54 ± 1.69 mm, 4.23 ± 0.69 mm, and 3.01 ± 0.79 mm, respectively. Optic canal diameter was 5.14 ± 0.47 mm anteriorly and 4.79 ± 0.64 mm posteriorly. Angulation was flat (>45 degrees) in 13% or acute (<45 degrees) in 87% specimens. Conclusions Anatomical variations in the optic strut are significant in planning for anterior clinoidectomy and optic-canal decompression. Our optic strut classification considers these variations relative to the prechiasmatic sulcus on preoperative imaging.

Multiple Dural Tuberculomas Presenting as Leptomeningeal Carcinomatosis

Objective and Importance. We present the rare occurrence of multiple dural-based tuberculomas mimicking leptomeningeal carcinomatosis in a young immunocompetent patient. Clinical Presentation. A 36-year-old man presented with a 2-month history of generalized epileptic activity and altered perception. Neurological examination was remarkable for bilateral Babinskis sign. Cranial magnetic resonance imaging (MRI) revealed multiple dural-based enhancing lesions with cerebral edema. Intervention. A right frontal craniotomy was performed for diagnosis. Histological examination revealed multiple confluent necrotizing and nonnecrotizing granulomas with giant cells which was consistent with tuberculosis (TB), and the patient was placed on anti-TB therapy for 24 months. Conclusion. To the best of our knowledge isolated diffuse involvement of the dura mater by TB, mimicking leptomeningeal carcinomatosis, as the sole manifestation of disease has not been reported before. Since pachymeningeal TB is rarely suspected when atypical radiological appearance is combined with the absence of systemic disease, biopsy is inevitably required for diagnosis.

Cerebellar granulocytic sarcoma: a case report.

Granulocytic sarcoma is a rare tumor composed of immature granulocytic cells that is usually associated with acute myelogenous leukemia. Intraparenchymal cranial localization without skull, meningeal, or bone marrow invasion is extremely rare. The mechanisms of intraparenchymal cranial localization of GS remains unknown, as only 10 cases with cerebellar granulocytic sarcoma have been previously reported. Herein, we report a four year old boy with cerebellar localization of granulocytic sarcoma.

Early Surgical Management of Middle Cerebral Artery Aneurysms Associated With Intracerebral Hematomas: The Uludag˘ University Experience

In this case series study, the surgical outcomes of 29 patients with intracerebral hematomas resulting from the rupture of middle cerebral artery aneurysms that were operated on within the first 12 hours after rupture were retrospectively analyzed. Preoperative cerebral angiography could be obtained in 12 (41.3%) of our patients. Outcome was assessed according to the Glasgow Outcome Scale at 6 months after surgery. Overall mortality was 48%. Of 12 patients in good preoperative condition, 6 (50%) had a favorable outcome (Glasgow Outcome Scale, 4 to 5), whereas of the 17 patients in poor preoperative condition only 1 (5.8%) had a favorable outcome (P=0.042). Our results suggest that despite early surgical treatment of patients with ruptured middle cerebral artery aneurysms associated with massive intracerebral hematoma, mortality continues to be high in patients with poor preoperative grades.