Arteriovenous aneurysm

Arteriovenous aneurysm is a pathological communication between the artery and the vein. Unlike physiological arteriovenous anastomoses with arteriovenous aneurysm there is no closing mechanism and physiological regulation of its function. Arteriovenous aneurysms may be congenital (ductal ducts, Parkes Weber disease with formation of massive hemangiomatous zones between the artery and vein, etc.). Acquired aneurysms occur more often (80%), they are caused by trauma (a bowl of the stitching or cutting nature) of the artery and vein, rupture of arterial aneurysm into the accompanying vein, less frequent biopsy of the vessel wall or application of an arteriovenous shunt for hemodialysis. The communication between the artery and the vein can occur with or without the formation of an aneurysmal sac. In the latter case, one should speak about the arteriovenous fistula. Such fistulas can be single and multiple. They can be located in close proximity to the heart and the periphery. The functional influence of the fistula on the heart and large vessels depends on the localization and the degree of blood flow through it. Fistula causes a discharge of blood with the development of hypoxia of peripheral tissues. The loss of blood volume from the arterial knee fistula to the venous is greater, the larger the diameter of the fistula and closer to the heart it is located. The discharge of blood from the artery to the vein leads to an overload of the right heart. The organism seeks to compensate for the insufficient cot on the periphery by an increase in cardiac output, spasm of peripheral vessels, and an increase in the volume of circulating blood ("the patient coats into his own venous system").

Symptoms, course. Palpable pulsating tumor, "machine-like" noise over the fistula, widening of the proximal veins with varicose veins pulsation, widening of the proximal artery with the formation of additional loops on the angiogram, peripheral fistulas lead to the development of symptoms of chronic arterial insufficiency. When clamping the leading artery or fistula, noise sometimes disappears, the pulse is cut and the blood pressure increases (the symptom of Nicolodoni-Dobrovolskaya).

Complications: right ventricular failure, varicose or ischemic ulcers, edema, congestive limb dermatitis.

Treatment is only prompt. Its goal is to eliminate the fistula with the restoration of blood flow along the artery and vein. This is achieved by crossing the fistula to cover the defects of the artery wall and vein. This reconstruction is performed with arteriovenous fistulas located proximal to the elbow or knee joint. When localizing distal to these joints, ligation of all leading and leading arteries and veins can be performed.

The prognosis with timely operative treatment is favorable. The earlier the operative correction is made, the less and more reversible the circulatory disturbances and changes in the myocardium.