Arteriovenous malformation

Description:

Arteriovenous malformation (AVM) — pathological communication between veins and arteries, usually inborn. This pathology is widely known because of its emergence in the central nervous system, but it can be created in any place of an organism, for example, between a pulmonary trunk and an aorta (an open arterial channel).

Symptoms of the Arteriovenous malformation:

1. Hemorrhagic type of a course of a disease – in 50 – 70% of cases. Existence at the patient of arterial hypertension, the small size of a node of a malformation, its drainage in deep veins, and also AVM of a back cranial pole is characteristic for this purpose like a current.
2. The torpid type of a current, is characteristic of patients with AVM of the big sizes, its localization in bark, blood supply with branches of an average brain artery.
Hemorrhagic type:
In 50% of cases is the first symptom of manifestation of AVM that causes a lethal outcome at 10 - 15% (at aneurisms to 50%) and an invalidism of 20 - 30% of patients. (N. Martin et al., 1994).
The annual risk of hemorrhage makes 1,5 – 3% of AVM. Within the first year after hemorrhage risk repeated - 6% also increase with age. (R. Braun et al., 1990).
During life repeated hemorrhage happens at 34% of the patients who survived after the first, and among transferred the second (a lethality to 29%) - 36% suffer from the third. (G. Rasmussen 1996).
Bleeding from AVM is the reason of 5 - 12% of all maternal mortality, pregnant women have 23% of all intracraneal hemorrhages. (B. Karlsson et al., 1997)
The picture of subarachnoidal hemorrhage is observed at 52% of patients (Lebedev V. V., Krylov V. V., 2000).
47% of patients have complicated hemorrhage forms: with formation intracerebral (38%), subdural (2%) and mixed (13%) hematomas, the gemotompanada of ventricles develops at 47%.
Torpid type:
Convulsive syndrome (at 26 – 67% of patients with AVM)
Cluster headaches.
The progressing neurologic deficit, as well as at brain tumors.

Reasons of the Arteriovenous malformation:

Genetic predisposition to AVM and the facts of its transfer are by inheritance unknown. It is considered that AVM — not a hereditary disease.
In arteriovenous malformation, most often, there is no capillary network owing to what direct shunting of blood from the arterial pool in system of superficial and deep veins is performed.
Main mechanisms of pathological influence of an arteriovenous malformation on a brain:
- A gap patholologically the changed vessels of a ball or aneurisms of the arteries feeding AVM.
- The chronic circulatory unefficiency caused by arteriovenous shunting.
- Syndrome of break of normal perfused pressure.

Treatment of the Arteriovenous malformation:

Generally gives in to treatment by methods of endovascular surgery.
The principles of rendering the surgical help to patients with AVM.
1. Full treatment of patients with AVM demands a possibility of carrying out three main options of treatment – surgical, embolizations, radio surgical.
2. On AVM the surgeon having personal experience in this area has to carry out the decision on medical tactics and surgical intervention.
3. At discussion of a question of indications to active methods of treatment of patients with AVM proceed from a ratio of risk of a spontaneous course of a disease and risk of complications of this or that way of treatment.
4. The main objective of any kind of intervention is a full obliteration of a malformation for prevention of intracraneal hemorrhages.