Arteriovenous Malformations

results of complete AVM obliteration using endovascular techniques, however, are not known, since there is some suggestion that re-canalization may occur [22].

Endovascular embolization usually requires general or neuroleptic anesthesia to keep the patient motionless during the procedure. It also may require several staged procedures. First, a 5-7 French sheath is placed in the femoral artery and a diagnostic cerebral angiogram is performed using standard catheter angiography technique. The AVM characteristics are defined using conventional high-resolution angiography and a micro-catheter is co-axially advanced and placed into the intracranial circulation proximal to the AVM using a flow-directed micro-catheter or guidewire assistance. The AVM can then be further studied using microinjections to define nidal compartmental-ization, presence of aneurysms, location of intra-nidal fistulae and the pattern of venous drainage. Once the AVM anatomy and flow characteristics are understood, arterial feeders to be embolized are micro-catheterized and the embolic material is prepared. Embolization usually is accomplished with cyanoacrylate or, in some instances, silk. Attaching various chemical modulators to its basic structure to change the polymerization rate may modify cyanoacrylate; N-butyl cyanoacrylate (NBCA) is the present agent of choice. Vessel angioarchitec-ture determines the injection rate, volume and concentration of NBCA during AVM emboliza-tion.

The results and morbidity of AVM embolization have been described in several large clinical series [2,17,23]. Overall, between 2 and 18% of AVMs can be completely occluded using endovascular techniques. Procedural risk, however, is high - between 2 and 17% of patients suffer major or minor morbidity and mortality is between 1 and 4%. The overall risk of an ischemic complication per procedure is estimated to be 9.4%. These potential risks need to be considered and included in any decision making when embolization is used as an adjunct to surgery or radiosurgery. Inadvertent glue deposition in normal cerebral vessels, causing infarction, and catastrophic AVM rupture are the two most significant complications encountered during AVM embolization. AVM rupture may result from inadvertent NBCA placement into a draining vein, causing a sudden rise in nidal pressures and consequent hemorrhage. Alternatively, the NBCA bolus itself may rupture the nidus or cause partial nidal occlusion, diverting blood flow and pressure to other nidal segments, leading to rupture. The use of hypotension (60-80 mmHg systolic) for a short period during embolic injections and post-procedure hypotension (90-110 mmHg systolic) for 24-48 hours may help prevent AVM rupture. Thromboembolic complications during AVM embolization may be prevented by the administration of heparin, to achieve ACTs between 250 and 300 s during the procedure.

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Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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