Krit1 modulates beta 1-integrin-mediated endothelial cell proliferation.

Objective: Using ribonucleic acid interference on cultured cell lines, we examined the role of Krev interaction trapped 1 (krit1) and integrin cytoplasmic domain-associated protein-1 alpha (icap1alpha) in beta1-integrin-mediated cell proliferation.

Methods: Upon depletion of either krit1 or icap1alpha in the HeLa cells, umbilical vein endothelial cells, and microvascular endothelial cells, we examined the cell number and proliferation changes in the cells, followed by the evaluation of beta1-integrin-mediated mitogen-activated protein kinase signal pathway and microscopic study.

Results: Depletion of krit1 reduces cell number and decreases endothelial cell proliferation.

Frameless stereotaxy-assisted clipping of distal anterior cerebral artery aneurysm: technical note and case series.

Objective: Microsurgery for the clipping of cerebral aneurysms requires a working knowledge of the anatomy of the cerebral vasculature and its relationship to landmarks on the surface of the brain and along the skull base. However, for more distally located aneurysms of the anterior cerebral artery (ACA), locating the lesion can prove frustrating and may require much more extensive interhemispheric dissection than is otherwise needed for proximal control, exposure of the aneurysm, and clip application. We report a case series of five patients in which frameless stereotaxy and CT angiographic data sets were used to minimize the extent of surgery required to clip distal ACA aneurysms.

Persistent perioperative hyperglycemia as an independent predictor of poor outcome after aneurysmal subarachnoid hemorrhage.

Object: The authors of previous studies have shown that admission hyperglycemia or perioperative hyperglycemic events may predispose a patient to poor outcome after aneurysmal subarachnoid hemorrhage (SAH). The results of experimental evidence have suggested that hyperglycemia may exacerbate ischemic central nervous system injury. It remains to be clarified whether a single hyperglycemic event or persistent hyperglycemia is predictive of poor outcome after aneurysmal SAH.

Laparoscopic treatment of anterior sacral meningocele.

Background: Anterior sacral meningocele is a rare congenital malformation, whose open surgical treatment is well accepted. We present a laparoscopic approach as an adjunctive approach.

Methods: Five women who underwent laparoscopic transperitoneal surgery were clinically, radiologically, and surgically evaluated.

Transvenous embolization of a dural arteriovenous fistula of the laterocavernous sinus through the pterygoid plexus.

We present a novel access for transvenous embolization of a dural arteriovenous fistula of the laterocavernous sinus through the external jugular vein and the pterygoid plexus. The anatomy of the laterocavernous sinus is reviewed, and its clinical implications discussed in light of the case of a patient whose management was modified after identifying this anatomical variation.

Interaction between krit1 and malcavernin: implications for the pathogenesis of cerebral cavernous malformations.

Objective: Cerebral cavernous malformations (CCM) are a relatively common autosomal dominant disorder leading to the formation of vascular malformations in the nervous system. Mutations in krit1 and malcavernin, the proteins encoded by the genes at the CCM1 and CCM2 loci, respectively, are responsible for the majority of CCMs. Similar to integrin cytoplasmic domain-associated protein-1alpha, a known krit1 interactor, malcavernin is a phosphotyrosine binding protein.

Orthogonal interlocking tandem clipping technique for the reconstruction of complex middle cerebral artery aneurysms.

Objective: Complex aneurysms arising at the middle cerebral artery (MCA) bifurcation frequently present a microsurgical challenge to effectively obliterate while maintaining patency of the distal MCA branches. These aneurysms are often multilobed, with their long axis aligned with the long axis of the M1 trunk, placing the dome of the aneurysm in the surgeons' line of sight, preventing an unobstructed view of the entire bifurcation and proximal M1 segment. MCA aneurysms often have a broad neck, splaying the bifurcation.

Intracranial aneurysm following radiation therapy during childhood for a brain tumor. Case report and review of the literature.

Ionizing radiation therapy is associated with pathological vascular changes in intracranial vessels, most commonly in the form of vessel thrombosis and occlusion. The development of an intracranial aneurysm following such therapy, however, is far less common. In this report the authors describe a 24-year-old man in whom a distal middle cerebral artery aneurysm developed 15 years after radiotherapy, which was given as adjuvant treatment following resection of a medulloblastoma.

Hyperglycemia independently increases the risk of perioperative stroke, myocardial infarction, and death after carotid endarterectomy.

Objective: Clinical and experimental evidence suggests that hyperglycemia lowers the neuronal ischemic threshold, potentiates stroke volume in focal ischemia, and is associated with morbidity and mortality in the surgical critical care setting. It remains unknown whether hyperglycemia during carotid endarterectomy (CEA) predisposes patients to perioperative stroke and operative related morbidity and mortality.

Methods: The clinical and radiological records of all patients undergoing CEA and operative day glucose measurement from 1994 to 2004 at an academic institution were reviewed and 30-day outcomes were assessed.

Intracranial delivery of the nitric oxide donor diethylenetriamine/nitric oxide from a controlled-release polymer: toxicity in cynomolgus monkeys.

Objective: Diethylenetriamine/nitric oxide (DETA/NO) has been shown to be an effective treatment for delayed posthemorrhagic vasospasm when released abluminally from ethylene-vinyl acetate copolymer (EVAc). However, the observed mortality associated with this drug warrants further investigation. To establish a maximum tolerable dose, this study evaluated the toxicity of DETA/NO released from EVAc in a dose-escalation series in cynomolgus monkeys (Macaca fascicularis).

Systemic administration of simvastatin after the onset of experimental subarachnoid hemorrhage attenuates cerebral vasospasm.

Objective: Experimental evidence suggests that intercellular adhesion molecule-1 mediated leukocyte extravasation contributes to the pathogenesis of cerebral vasospasm. Simvastatin, an HMG-CoA reductase inhibitor, decreases intercellular adhesion molecule-1 expression and competitively inhibits leukocyte intercellular adhesion molecule-1 binding. We hypothesized that administration of simvastatin after the onset of subarachnoid hemorrhage (SAH) would attenuate perivascular granulocyte migration and ameliorate cerebral vasospasm in a rabbit model of SAH.

Controlled release of a nitric oxide donor for the prevention of delayed cerebral vasospasm following experimental subarachnoid hemorrhage in nonhuman primates.

Object: Results of prior studies in rats and rabbits show that the alteration of vasomotor tone in vasospasm following periadventitial blood exposure may be reversed, at least in part, by the administration of compounds releasing nitric oxide (NO). The authors have now generalized this finding to nonhuman primates.

Methods: Ten cynomolgus monkeys underwent cerebral angiography before and 7 days following the induction of subarachnoid hemorrhage (SAH) by the placement of 2 to 3 ml clotted autologous blood around the supraclinoid carotid, proximal anterior cerebral, and proximal middle cerebral arteries.

Evaluation of a distal pericallosal aneurysm visualized with 3-dimensional digital subtraction angiography: case report and treatment implications.

Background: Digital subtraction angiography (DSA) is considered the gold standard in the evaluation of cerebrovascular structures. Recently, 3-dimensional DSA (3D-DSA) has been increasingly used to obtain detailed information about the morphology and dimensions of intracranial aneurysms. We report the case of a patient who presented with a distal pericallosal artery aneurysm, which appeared by 2D imaging to be a fusiform, possible mycotic aneurysm.

Local delivery of ibuprofen via controlled-release polymers prevents angiographic vasospasm in a monkey model of subarachnoid hemorrhage.

Objective: Adhesion and migration of leukocytes into the periadventitial space play a role in the pathophysiology of vasospasm after subarachnoid hemorrhage (SAH). Intercellular adhesion molecule-1 is a determinant cell adhesion molecule involved in this process. Ibuprofen has been shown to inhibit intercellular adhesion molecule-1 upregulation and prevent vasospasm in animal models of SAH.

Supratentorial arteriovenous malformations.

Arteriovenous malformations are a heterogeneous group of intra-axial central nervous system vascular lesions consisting of tangles of abnormal arteriovenous connections without intervening capillary beds. The heterogeneity of arteriovenous malformations is described by the Spetzler-Martin grading scale, a scale that also forms the basis for clinical decision making. The microsurgical treatment of appropriately selected supratentorial arteriovenous malformations is based on the tenets of circumferential isolation and transection of arterial feeders, preservation of vessels en passant and surrounding functional neural tissue, and skeletonization and transection of venous drainage.

Contralateral approaches to multiple cerebral aneurysms.

Not infrequently, patients with bilateral cerebral aneurysms are encountered. In such patients, the ability to treat bilateral aneurysms through a unilateral approach spares the patient the risk and inconvenience associated with a separate craniotomy. The contralateral approach for aneurysm repair is technically feasible and safe in appropriately selected patients.

Orbitozygomatic approach to basilar apex aneurysms.

Basilar apex region aneurysms are among the most complex cerebral aneurysms. They are not, however, among the most common aneurysms, and increased use of endovascular treatment has further decreased the number of patients with these lesions who undergo surgery. Nonetheless, not all basilar apex aneurysms are amenable to coil embolization, and neurosurgeons must be prepared to treat patients with basilar apex aneurysms surgically.

Segmental agenesis of the internal carotid artery distal to the posterior communicating artery leading to the definition of a new embryologic segment.

We report a case of segmental agenesis of the right internal carotid artery (ICA) in a 53-year-old woman, associated with a saccular aneurysm of the left anterior cerebral artery (A1 segment) presenting with a right hemispheric transient ischemic attack. The agenetic segment was located distal to the origin of the posterior communicating artery (PComA), as documented both angiographically and by direct surgical inspection. This observation suggests the existence of a previously unrecognized embryologic segment of the ICA, located between the PComA origin and the terminal bifurcation of the ICA into the anterior and middle cerebral arteries.

Discovering the novel surgical approach.

Discovering the novel surgical approach requires surgeons to look beyond the dogma of current practices. By applying simple principles and concepts, such as the two-point method, working depth, working area, and angle of attack, novel approaches can evolve from existing approaches to improve exposure and decrease patient morbidity. The EOZ and ELSI are two examples in which these principles have been applied to generate novel surgical approaches by modifying existing ones.

De novo aneurysm formation 6 and 22 months after initial presentation in two patients.

Two cases of angiographically and surgically documented de novo intracranial aneurysm formation are reported. The first patient, a 32-year-old woman, developed two new aneurysms within a 6-month period, and the second patient, a 27-year-old woman, developed two new aneurysms within a 22-month period. In both patients, the new aneurysms were symptomatic, causing stroke and subarachnoid hemorrhage, respectively.

Developmental venous anomalies and sinus pericranii in the blue rubber-bleb nevus syndrome. Case report.

Blue rubber-bleb nevus syndrome (BRBNS) is a developmental disorder that originally was identified by the presence of distinctive cutaneous and gastrointestinal hemangiomas. More recently it has been recognized that the number of affected organs is larger and that BRBNS includes central nervous system vascular malformations. A 52-year-old woman in whom intracranial vascular malformations had been diagnosed earlier presented for evaluation.

Prevention of cerebral vasospasm by a humanized anti-CD11/CD18 monoclonal antibody administered after experimental subarachnoid hemorrhage in nonhuman primates.

Object: Leukocyte-endothelial cell interactions occurring in the first hours after subarachnoid hemorrhage (SAH) initiate changes in the endothelium and vessel wall that lead to an influx of leukocytes and the development of chronic vasospasm days later. Upregulation of intercellular adhesion molecule-1 (ICAM-1), also called CD54, appears to be a crucial step in this process. There is increasing experimental evidence that blocking the interaction between ICAM-1, which is expressed on endothelium, and integrins such as lymphocyte function-associated antigen-1 (CD11a/CD18) and macrophage antigen-1 (complement receptor 3, CD11b/CD18), which are expressed on the surface of leukocytes,prevents not only inflammation of vessel walls but also chronic vasospasm.