The live cadaver model presents a useful simulation of the conditions of live surgery for clipping cerebral aneurysms and managing intraoperative rupture. This model provides a means of practice and promotes team management of intraoperative cerebrovascular critical events. Precise metric measurement for evaluation of training performance improvement can be applied.

Cervical dural arteriovenous fistulas (dAVFs) are a rare cause of intracranial subarachnoid hemorrhage (SAH) but should be considered when other sources are not found. Subarachnoid hemorrhage caused by dAVF is thought to occur as a result of venous hypertension in most cases. The clinical presentation, acute onset of severe headache, is similar to that in patients with other causes of SAH; however, severe neurological deficits (Hunt and Hess Grade IV and V SAH) have not been reported in SAH caused by cervical dAVFs. Patients with this type of SAH commonly report suboccipital headache, neck pain, and nausea, and thus these hemorrhages can be easily dismissed as perimesencephalic SAH. Vigilant evaluation with 4-vessel cerebral angiography, including selective catherization of both proximal vertebral arteries, should be performed. The practice of unilateral vertebral artery injection with reflux into the contralateral vertebral and posterior inferior cerebellar arteries has the potential to overlook cervical dAVF. Magnetic resonance imaging may be useful to evaluate for other causes of SAH but is probably not sensitive for the identification of a cervical dAVF. Surgical treatment of this lesion has an excellent outcome.

No abstract

A cute hydrocephalus is a common sequela of aneurysmal SAH effectively treated with an EVD. Ultimately, a significant proportion of patients may need conversion of their EVD to a permanent VP shunt due to development of chronic hydrocephalus.Although it is a common neurosurgical practice to convert the EVD to a VP shunt, the available literature offers little guidance regarding the technique and site for the placement of the ventricular catheter. Some neurosurgeons prefer using the same EVD hole, whereas in some units it is common practice to use a new, "fresh" site. Each technique has its own pros and cons. Using the same site that had been used for the EVD provides atraumatic entrance of the proximal catheter into the ventricular system through an established track and minimizes the operative risks of hemorrhage and catheter malpositioning. However, Object. The purpose of this study was to determine the incidence of shunt infection in patients with subarachnoid hemorrhage (SAH) after converting an external ventricular drain (EVD) to a ventriculoperitoneal (VP) shunt using the existing EVD site. The second purpose was to assess the risk of shunt malfunction after converting the EVD to a permanent shunt irrespective of the cerebrospinal fluid (CSF) protein and red blood cell (RBC) counts.Methods. Data obtained in 80 consecutive adult patients (18 men and 62 women, mean age 60.8 years, range 33-85 years) who underwent direct conversion of an EVD to a VP shunt for post-SAH hydrocephalus between August 2002 and March 2007 were retrospectively reviewed. In each patient, the existing EVD site was used to pass the proximal shunt catheter. In no patient was VP shunt insertion delayed based on preoperative RBC or protein counts.Results. The mean period of external ventricular drainage before VP shunt placement was 14.1 days (range 3-45 days). No patient suffered ventriculitis. The mean perioperative CSF protein level was 124 mg/dl (range 17-516 mg/ dl). The mean and median perioperative RBC values in CSF were 14,203 RBCs/mm 3 and 4600 RBCs/mm 3 (range 119-290,000/mm 3 ), respectively. No patient was lost to follow-up. The mean follow-up duration was 24 months (range 2-53 months). Three patients (3.8%) had shunt malfunction related to obstruction of the shunt system after 15 days, 2 months, and 18 months, respectively. There were no shunt-related infections. No patient suffered a clinically significant hemorrhage from ventricular catheter placement after VP shunt insertion.Conclusions. In adult patients with aneurysmal SAH, conversion of an EVD to a VP shunt can be safely done using the same EVD site. In this defined patient population, protein and RBC counts in the CSF do not seem to affect shunt survival adversely. Thus, conversion of an EVD to VP shunt should not be delayed because of an elevated protein or RBC count. (DOI: 10.3171.JNS.2008.109.12.1001 Key WoRDS • communicating hydrocephalus • shunt infection • shunt malfunction • subarachnoid hemorrhage 1001Abbreviations used in this paper: CSF = cerebrospinal fluid...

SUMMARY:Brain arteriovenous malformations are frequently associated with the presence of intracranial aneurysms at a higher-thanexpected incidence based on the frequency of each lesion individually. The identification of intracranial aneurysms in association with AVMs has increased due to improvement in diagnostic techniques, particularly 3D and superselective conventional angiography. Intracranial aneurysms may confer a higher risk of hemorrhage at presentation and of rehemorrhage in patients with AVMs and therefore may be associated with a more unfavorable natural history. The association of AVMs and intracranial aneurysms poses important therapeutic challenges for practicing neurosurgeons, neurologists, and neurointerventional radiologists. In this report, we review the classification and radiology of AVM-associated intracranial aneurysms and discuss their clinical significance and implications for treatment. ABBREVIATION: IA ϭ intracranial aneurysm

Screening to identify patients at risk for development of hemorrhagic complications from underlying structural vascular lesions before the use of IV rtPA with computed tomography angiography should be considered.

BACKGROUND AND PURPOSE:Tentorial dural arteriovenous fistulas are characterized by a high hemorrhagic risk. We evaluated trends in outcomes and management of tentorial dural arteriovenous fistulas and performed a meta-analysis evaluating clinical and angiographic outcomes by treatment technique.

Developmental venous anomalies (DVAs), formerly known as venous angiomas, have become the most frequently diagnosed intracranial vascular malformation. DVAs are currently considered congenital cerebrovascular anomalies with mature venous walls that lack arterial or capillary elements. They are composed of radially arranged medullary veins, which converge in an enlarged transcortical or subependymal collector vein, and have characteristic appearances (caput medusae) on magnetic resonance imaging and angiography. DVAs were once thought to be rare lesions with substantial potential for intracerebral hemorrhage and considerable morbidity. The prevalence of incidental and asymptomatic DVAs has been more apparent since the advent of magnetic resonance imaging; recent cohort studies have challenged the once-held view of isolated DVAs as the cause of major neurological complications. The previously reported high incidence of intracerebral hemorrhage associated with DVAs is currently attributed to coexistent, angiographically occult cavernous malformations. Some patients may still have noteworthy neurological morbidity or die as a result of acute infarction or hemorrhage directly attributed to DVA thrombosis. DVAs can coexist with cavernous malformations and arteriovenous malformations. Such combination or transitional forms of malformations might suggest common pathways in pathogenesis. Recent data support a key role for DVAs in the pathogenesis of mixed vascular malformations.