Arteriovenous malformations

Known arteriovenous malformation, aneurysm, or intracranial neoplasm... 

Known structural vascular lesion (e.g., arteriovenous malformation)... 

Hemorrhagic strokes account for 12% of strokes and include subarachnoid hemorrhage, intracerebral hemorrhage, and subdural hematomas. Subarachnoid hemorrhage may result from trauma or rupture of an intracranial aneurysm or arteriovenous malformation. Intracerebral hemorrhage occurs when a ruptured blood vessel within the brain parenchyma causes formation of a hematoma. Subdural hematomas are most often caused by trauma. 

In subarachnoid hemorrhage due to a ruptured intracranial aneurysm or arteriovenous malformation, surgical intervention to clip or ablate the vascular abnormality substantially reduces mortality from rebleeding. The benefits of surgery are less well documented in cases of primary intracerebral hemorrhage. In patients with intracerebral hematomas, insertion of an intraventricular drain with monitoring of intracranial pressure is... 

History of intracranial hemorrhage, arteriovenous malformation, or aneurysm... 

AUC area under the curve AV atrioventricular AVM arteriovenous malformation (blood vessel abnormality) b/c because BB beta blockers BCL B-cell lymphoma BCL-ABL a type of cancer gene bid twice a day (Latin bis in die ) BiPAP bilevel continuous airway pressure... 

Contraindications Active internal bleeding, arteriovenous malformation or aneurysm, cerebrovascular accident (CVA) with residual neurologic defect, history of CVA (within the past 2 yr) or oral anticoagulant use within the past 7 days unless PT is less than 1.2 X control, history of vasculitis, hypersensitivity to murine proteins, intracranial neoplasm, prior IV dextran use before or during percutaneous transluminal coronary angioplasty (PTCA), recent surgery or trauma (within the past 6 wk), recent (within the past 6 wk or less) GI or GU bleeding, thrombocytopenia (less than 100,000 cells/pl), and severe uncontrolled hypertension... 

Contraindications Active internal bleeding or a history of bleeding diathesis within previous 30 days, arteriovenous malformation or aneurysm, history of intracranial hemorrhage, history of thrombocytopenia after prior exposure to tirofiban, intracranial neoplasm, major surgical procedure within previous 30 days, severe hypertension, stroke... 

A 13-year-old boy underwent a 17-hour craniotomy in an attempt to resect an arteriovenous malformation with propofol-based anesthesia. He developed frank propofol infusion syndrome after 74 hours of postoperative propofol sedation in the neurosurgical ICU (used to manage intracranial hypertension). Echocardiography showed severe biventricular dysfunction despite extraordinary pharmacological support. Extracorporeal circulation with membrane oxygenation (ECMO) was instituted at the bedside via cannulation of the left femoral vessels. Hemofiltration... 

Heindel CC, G.S. Dugger, EC. Guinto (1975) Spinal arteriovenous malformation with hypogastric blood supply. J. Neu-rosurg. 42, 462-464... 

Rosenblum B, Oldfield EH, Doppman JL, Di Chiro G (1987) Spinal arteriovenous malformations a comparison of dural arteriovenous fistulas and intradural AVM s in 81 patients. J Neurosurg 67 795-802 Rosenkranz M, Grzyska U, Niesen W, Fuchs K, Schummer W, Weiller C, Rother J (2004) Anterior spinal artery syndrome following periradicular cervical nerve root therapy. J Neurol 251 229-231... 

Spiller W (1909) Thrombosis of the cervical anterior median spinal artery. I Nerv Ment Dis 36 601 Stein SC, Ommaya AK, Doppman JL, Di Chiro G (1972) Arteriovenous malformation of the cauda equina with arterial supply from branches of the internal iliac arteries. Case report. J Neurosurg 36 649-651 Stepper F, Lovblad KO (2001) Anterior spinal artery stroke demonstrated by echo-planar DWI. Eur Radiol 11 2607-2610 Suh T.H., Alexander L (1939) Vascular system of the human spinal cord. Arch Neurol Psychiat 41 659-677 Suzuki T, Kawaguchi S, Takebayashi T, Yokogushi K, Takada J, Yamashita T (2003) Vertebral body ischemia in the posterior spinal artery syndrome case report and review of the literature. Spine 28 E260-264... 

Moyamoya seems to be mainly confined to the Japanese and other Asians, and in most cases the cause is unknown (Bruno et al. 1988 Chiu et al. 1998). Some cases are familial (Kitahara et al. 1979) others appear to be caused by a generalized fibrous disorder of arteries (Aoyagi et al. 1996), and a few may result from a congenital hypoplastic anomaly affecting arteries at the base of the brain, or associated with Down s syndrome (Cramer et al. 1996). The syndrome may present in infancy with recurrent episodes of cerebral ischemia and infarction, mental retardation, headache, epileptic seizures and, occasionally, involuntary movements. In adults, subarachnoid or primary intracerebral hemorrhage are also common owing to rupture of collateral vessels. There have also been a few reports of associated intracranial aneurysms (Iwama et al. 1997) and also of cerebral arteriovenous malformations. 

Fig. 7.1. Intracerebral hemorrhage, (a) A CT brain scan showing a typical deep "hypertensive" primary intracerebral hemorrhage, (b) These CT brain scans showing a right frontal arteriovenous malformation causing hemorrhage.

Fig. 7.5. Arteriovenous malformation, A T2-weighted MRI (a) and cerebral angiogram (b) showing a dural arteriovenous malformation (arrows) at the right cerebellopontine angle, causing tinnitus.

Arteriovenous malformations present most commonly with signs consistent with a space-occupying lesion or seizures and consist of an abnormal fistulous connection(s) between one or more hypertrophied feeding arteries and dilated draining veins (Clatterbuck et al. 2005) (Fig. 7.5). The blood supply is derived from one cerebral artery or, more often, several, sometimes with a contribution from branches of the external carotid artery. Arteriovenous malformations vary from a few millimeters to several centimeters in diameter. Approximately 15% are associated with aneurysms on their feeding arteries. Some grow during life but a few shrink or even disappear, and some are multiple. These fistulae occur in or on the brain, or in the dura of the intracranial sinuses. 

Headache, although common, is not by itself diagnostically helpful and may well be a coincidence. Rarely, a bruit can be heard over the skull or orbits. A brainstem arteriovenous malformation can present similarly to multiple sclerosis, with fluctuating symptoms and signs of brainstem dysfunction, perhaps caused by recurrent hemorrhage. 

Telangiectasias are collections of dilated capillaries that are usually of no clinical significance (Milandre et al. 1987). They may be associated with hereditary hemorrhagic telangiectasia (the Osler-Weber-Rendu syndrome), but this is more likely to be associated with neurological complications from a pulmonary arteriovenous malformation with right-to-left shunting, such as cerebral hypoxia, brain abscess, paradoxical and septic embolism, or from an associated intracranial arteriovenous malformation or aneurysm (McDonald et al. 1998). 

European Radiology 15 448-452 Clatterbuck RE, Hsu FP, Spetzler RF (2005). Supratentorial arteriovenous malformations. Neurosurgery 57 164-167 Cordonnier C, Al-Shahi Salman R, Wardlaw J (2007). Spontaneous brain microbleeds systematic review, subgroup analyses and standards for study design and reporting. Brain 130 1988-2003... 

Pulmonary arteriovenous malformation (Ch. 6) nfective endocarditis (Ch. 6) nflammatory bowel disease (Ch. 6) nfective endocarditis (Ch. 6)... 

Pretreatment CT showing hypodensity which could represent evolving infarct over three hours old mass effect or edema tumor, aneurysm or arteriovenous malformation... 

Pontine hemorrhages are fatal in around 50% of patients (Wijdicks and St. Louis 1997). Those caused by cavernomas or arteriovenous malformations have a better outcome (Rabinstein et at 2004). The management of patients with hypertensive pontine hemorrhage is usually conservative, but some case reports have documented successful stereotactic aspiration. However, there is likely publication bias and the natural history of the condition is difficult to predict since patients with small hemorrhages do well with conservative management. 

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