Arteriovenous malformation (AVM) is a pathological connection between veins and arteries, usually congenital. This pathology is widely known because of its occurrence in the central nervous system, but it can form anywhere in the body, for example, between the pulmonary trunk and the aorta ( open ductus arteriosus ).
| Arteriovenous malformation | |
|---|---|
| ICD-10 | Q 27.3 , Q 28.0 , Q 28.2 |
| ICD-10-KM | |
| ICD-9 | 747.6 , 747.81 |
| Diseasesdb | 15235 |
| Medlineplus | 000779 |
| eMedicine | topic list |
| Mesh | D001165 |
The genetic predisposition to AVM and the facts of its transmission by inheritance are unknown. It is believed that AVM is not a hereditary disease.
In arteriovenous malformations, most often, there is no capillary network, as a result of which there is a direct bypass of blood from the arterial pool to the system of superficial and deep veins.
The main mechanisms of the pathological effect of arteriovenous malformation on the brain:
- Rupture of pathologically altered vessels of the glomerulus or aneurysms of arteries that feed the AVM.
- Chronic circulatory failure caused by arteriovenous bypass surgery.
- Breakthrough syndrome of normal perfusion pressure.
Arteriovenous malformations of the central nervous system
Arteriovenous malformations (AVM) of the brain and spinal cord are a relatively infrequent nosological form, which can, however, cause severe neurological disorders and death. Although in most cases the disease manifests itself as intracranial or spinal hemorrhage, epileptic seizures, progressive myelopathy, the improvement of diagnostic methods leads to an increase in the frequency of diagnosis of AVM of the central nervous system at the preclinical stage. In the last decade, methods of surgical treatment of patients with AVM, the possibility of intravascular occlusion of malformations, and the availability of radiosurgery have undergone significant improvement. There are recommendations for the diagnosis and treatment of AVM, based on an analysis of published studies on the treatment of patients with AVM [1] .
Clinical Arteriovenous Malformations Clinic
- Hemorrhagic type of disease course - in 50 - 70% of cases. This type of course is characterized by the presence of arterial hypertension in the patient, the small size of the malformation node, its drainage into the deep veins, as well as the AVM of the posterior cranial fossa.
- The torpid type of course is characteristic of patients with large-sized AVMs, its localization in the cortex, and blood supply to the branches of the middle cerebral artery.
Hemorrhagic type:
In 50% of cases, it is the first symptom of AVM manifestation, which leads to a fatal outcome in 10–15% (with aneurysms up to 50%) and disability in 20–30% of patients [2] .
The annual risk of hemorrhage from AVM is 1.5 to 3%. During the first year after hemorrhage, the risk of recurrence is 6% and increases with age [3] .
During life, repeated hemorrhage occurs in 34% of patients who survived after the first, and among those who survived the second (mortality up to 29%) - 36% suffer from the third [4] .
Bleeding from AVM is the cause of 5–12% of all maternal mortality, 23% of all intracranial hemorrhages in pregnant women [5] .
The picture of subarachnoid hemorrhage is observed in 52% of patients [6] .
47% of patients have complicated forms of hemorrhage: with the formation of intracerebral (38%), subdural (2%) and mixed (13%) hematomas, ventricular hemotamponade develops in 47%.
Torpid type:
Convulsive syndrome (in 26 - 67% of patients with AVM)
Cluster headaches.
Progressive neurological deficit, as with brain tumors.
AVM Diagnostics
To diagnose a vascular disease such as arteriovenous malformation, various diagnostic methods are used.
- Angiography
- CT angiography
- MR angiography
- Ultrasound - dopplerography
Treatment
It is generally treatable by endovascular surgery .
The principles of surgical care for patients with AVM.
- The full treatment of patients with AVM requires the possibility of carrying out three main treatment options - surgical, embolization, radiosurgery.
- The decision on medical tactics and surgical intervention on the AVM should be made by a surgeon with personal experience in this area.
- When discussing the issue of indications for active treatment methods for patients with AVM, the risk ratio of the spontaneous course of the disease and the risk of complications of one or another treatment method are based on.
- The main task of any type of intervention is the complete obliteration of malformation for the prevention of intracranial hemorrhage.
The degree of radicalism of various AVM treatment methods
- Surgical treatment - a radical extirpation of an AVM with a volume of up to 100 ml is technically feasible.
- Embolization - a radical shutdown of the AVM from the bloodstream is possible in 10-40% of patients, in other cases - obliteration of the AVM occurs at 15 - 75%.
- Radiosurgical treatment - a complete obliteration of SM with a diameter of less than 3 cm is possible in 85% of patients (over 2 years).
Currently, combined treatment methods are actively used (embolization + surgery and / or radiosurgery and other combinations). This can significantly reduce the risk of complications and increase the radicalism of the intervention.
Notes
- ↑ Clinical recommendations for the diagnosis and treatment of arteriovenous malformations of the central nervous system - Internet community of neurosurgeons in Russia . neuro-online.ru. Date of treatment March 5, 2017.
- ↑ N. Martin et al., 1994
- ↑ R. Braun et al., 1990
- ↑ G. Rasmussen 1996
- ↑ B. Karlsson et al., 1997
- ↑ Lebedev V.V., Krylov V.V., 2000