subclavian steal syndrome
Introduction
Introduction to the subclavian artery stealing syndrome Subclavian sterility syndrome (subclavianstealsyndrome) refers to the proximal part of the vertebral artery at the subclavian artery or the brachiocephalic trunk. There is partial or complete occlusive damage due to siphoning (stolen blood). The blood flow in the affected vertebral artery is retrograde, entering the distal heart segment of the affected subclavian artery, resulting in ischemic attack of the vertebral artery and ischemic symptoms of the upper limb of the affected side. Angiography confirmed stenotic lesions in the proximal concentric region of the subclavian artery, and blood flow in the lateral vertebral artery was retrograde, first reported by Contomi in 1960, but the patient had no neurological disorders. Reivich further reported angiographic data in 1961 and The symptoms of vertebral-basal arterial insufficiency appeared and an animal (dog) experiment was performed to confirm this phenomenon. It was pointed out that this is a new vascular syndrome and was named "under the subclavian artery steal syndrome". This syndrome can also be seen in the dry head of the head, because the retrograde blood also enters the subclavian artery, it can also be called "under the subclavian artery steal syndrome." basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: disturbance of consciousness
Cause
Causes of subclavian artery stealing syndrome
(1) Causes of the disease
Atherosclerosis is the most common cause of occlusion, and very few are congenital, rare in chest trauma, avascular disease, giant cell arteritis, embolism or tumor thrombus.
1. Atherosclerosis: The subclavian or brachiocephalic atherosclerosis often has the same damage in other blood vessels in the extracranial neck. For example, in a group of 168 cases, 80% of the total neck is present by angiography. Intracervical, extracranial or vertebral artery damage, 37 of the 74 adult patients (57.8%) had other cervical vascular lesions, and the most common internal carotid artery was due to atherosclerosis. A cause of systemic vascular damage.
2. Congenitality: Pieroni (1972) reported a case of congenital subclavian artery occlusion confirmed by angiography of the heart, this case of subclavian artery proximal confinement, the author reviewed 26 cases, indicating that congenital patients often have cardiovascular Defect, that is, if the syndrome occurs in the left aortic arch or the aortic arch is narrowed, there are many patent ductus arteriosus and ventricular septal defect. For example, if the right aortic arch is right, there is often tetralogy of Fallot and the right aortic arch is right. In the position, the aortic arch was normal, the subclavian artery was localized with dysplasia, atresia or isolation. A rare report was also found in the proximal subclavian artery dysplasia of the bilateral subclavian artery, and there was a bilateral augmentation of the aorta.
3. Iatrogenicity: There are reports of 12 cases of tetralogy of Fallot. When Blalock Taussig is performed, when the proximal subclavian artery and the pulmonary artery are anastomosed, angiography confirms that there is "the subclavian artery stealing blood"; In the case of the symptoms of insufficient blood supply to the basilar artery, the right subclavian artery originates from the aorta and is parallel to the back of the esophagus. This syndrome can also be caused when vascular surgery is performed for patients with malnutrition and dysphagia.
4. Trauma: A car accident causes a chest injury. In the subclavian artery, contusive thrombosis occurs on the proximal side of the vertebral artery at the beginning of the vertebral artery, resulting in this syndrome.
5. Others: such as rheumatic heart disease complicated by the first segment of the left subclavian artery embolism, no pulse, metastatic tumor thrombus and giant cell arteritis.
(two) pathogenesis
1. "Stolen blood" is caused by siphoning. Under normal physiological conditions, the arterial pressure of the intracranial artery is lower than the pressure of the aortic arch or its branches to maintain normal intracranial blood supply. When this pressure gradient is reversed, the blood can be The head is countercurrent to the heart or flows to the upper limbs. The "clavicle stealing blood" is the result of the lesion causing the subclavian artery to be lower than the basilar artery (Fields et al., 1972). Animal experiments have found that when the acute occlusion dog is right When the subclavian artery is close to the heart, it causes retrograde blood flow in the right vertebral artery. This blood flow retrograde depends on the blood pressure difference between the systemic blood pressure and the right vertebral-clavicular artery junction. When the blood pressure difference increases, the blood flow is reversed. Sammartino et al., 1964).
2. The factors causing blood stasis in the subclavian artery are occluded in the subclavian artery or the brachial plexus near the heart side, but not all of the phenomenon of "stealing blood" occurs, and the blood flow of the vertebral artery is reversed. There must be many physiological or anatomical The most important factor is the degree of stenosis of the subclavian artery. In patients with blood stasis, the systolic pressure difference between the two upper limbs is often larger than that of the person who does not steal blood. In addition, the collateral circulation is also considered.
3. The way to "steal the blood"
(1) When one side of the subclavian or the head arm is closed near the heart, the blood flow direction is the contralateral vertebral artery basilar artery affected side vertebral artery the distal part of the affected side of the subclavian artery.
(2) When the head arm is dry occlusion, in addition to the above-mentioned manner, the blood passes through the posterior communicating artery the affected internal carotid artery the common carotid artery the distal end of the affected subclavian artery.
(3) The left subclavian artery and the right brachiocephalic trunk are simultaneously narrowed, and the blood passes through the posterior communicating artery of both sides the basilar artery the vertebral artery on both sides the telecentric segment of the bilateral subclavian artery.
Vollmer et al. (1973) divided 40 cases as follows:
1 vertebral artery - vertebral artery (66%);
2 carotid-basal artery (26%);
3 external carotid artery - vertebral artery (6%);
4 carotid artery - subclavian artery (accounting for 2%) stealing blood, the company also pointed out that only the affected side of the internal carotid artery occlusion damage, the external carotid artery - vertebral artery shunt.
4. The meaning of collateral circulation when "stolen blood"
When the subclavian artery steals blood, the appearance of collateral circulation is a response to occlusion. The following five collateral circulations are common in cerebral angiography:
1 vertebral artery and vertebral artery;
2 thyroid artery and thyroid artery;
3 cervical ascending artery and ipsilateral vertebral artery and branch of anterior vertebral artery;
4 the branch of the ipsilateral cervical ascending artery and vertebral artery;
5 occipital branch of the external carotid artery and the muscle branch of the ipsilateral vertebral artery (occipital anastomosis).
Theoretically, the basilar artery ring is a good collateral circulation system, but it is limited by congenital development, especially the posterior communicating artery dysplasia (22%). It can be severe when there is large blood vessel obstruction outside the skull. Affecting blood circulation, angiographic observation of 42 patients with this syndrome found that in patients with vertebrobasilar insufficiency, the blood flow of the posterior cerebral artery originated from the internal carotid artery (normally from the basilar artery); The arteries are embryonic (ie, the artery is straight from the internal carotid artery to the rear) and the junction of the posterior communicating artery and the posterior cerebral artery is at an angle (indicating dysplasia), which is higher than in patients without vertebral-based blood supply.
Prevention
Prevention of steal syndrome of subclavian artery
Early detection, early diagnosis, early treatment is the key.
Complication
Complications of subclavian artery stealing syndrome Complications
Symptoms of vertebral-basal arterial insufficiency are the most common and can be considered as secondary clinical manifestations of the disease.
Symptom
Symptoms of subclavian artery steal syndrome (common symptoms) common symptoms, fatigue, arthritis, diarrhea, dysphagia, convulsions, dizziness, vertigo, atherosclerosis, visual impairment, syncope
1. The average male is more common than the female, the age is more than 50 years old, and the left side is more common. This may be because the left subclavian artery has a large angle at the beginning of the aorta and is susceptible to blood flow. Causes atherosclerosis, this syndrome may have neurological symptoms of vertebral-basal arterial insufficiency and ischemic symptoms of upper limbs. Symptoms of insufficient carotid blood supply are rare, only seen in the head or the bilateral subclavian artery stenosis. patient.
2. The most common symptoms of vertebral-basal arterial insufficiency are vertigo, limb paralysis, paresthesia, bilateral visual impairment, ataxia, diplopia, syncope, and rare intermittent claudication, difficulty in pronunciation, Dysphagia, tinnitus, convulsions, headaches and mental disorders, a small number of "drop attack" can occur, manifested as no aura, sudden onset of lower extremity muscle loss and fall, without consciousness disorder, and can quickly recover, possible It is caused by ischemia of the medullary vertebral body. Generally, patients with this syndrome will not cause permanent nerve damage.
3. The common symptoms of upper limb ischemic symptoms are intermittent exercise, limb weakness, pain and paresthesia, and very few causes finger cyanosis or necrosis.
4. General signs
(1) Blood pressure: The blood pressure of the upper limbs of the affected side is reduced. The difference in systolic blood pressure between the two upper limbs can be 20-150 mmHg, and the majority difference is 20-70 mmHg. From the perspective of angiography, degree of symptoms and frequency of attack, blood pressure difference and damaged blood vessel stenosis The extent of the relationship
(2) Pulse: Most of the radial artery in the affected side is weakened or disappeared, and some of the radial artery or subclavian artery pulsation is also weakened or disappeared. In addition, the pulse on the affected side is late, which is due to the pulse wave from the contralateral vertebral artery to the affected vertebra. The artery, then the wrist, is far away.
(3) vascular murmurs on the supraclavicular region: most audible and systolic murmurs, and the affected limbs may aggravate the murmur.
Such as:
1 In the medical history, there is insufficient blood supply to the vertebral-basal artery, especially the ischemic symptoms of the upper limb.
2 examination found that the systolic blood pressure difference between the two arms was above 20mmHg.
3 pulse is late.
4 There is a vascular murmur in the subclavian-vertebral artery area, that is, the disease should be considered, but special examination is still needed to confirm the diagnosis.
Examine
Examination of subclavian artery stealing syndrome
Routine examination of blood and CSF is generally non-specific.
1. Transcranial Doppler ultrasonography (TCD) is used to detect the blood vessels and blood flow in the neck. The suspects should undergo the ipsilateral beam arm test to detect changes in the reverse blood flow of the vertebral artery (Huang Yining et al., 1997).
2. Digital subtraction angiography (DSA) focuses on the aortic arch, bilateral subclavian artery and common carotid artery. If the subclavian or brachiocephalic trunk is found, the proximal part of the vertebral artery begins to be severely narrow. For the lumen of 85%) or almost occlusion, and even visible contrast agent through the contralateral vertebral artery up to the basilar artery, and descending (countercurrent) to the distal side of the affected subclavian artery can be confirmed.
Diagnosis
Diagnosis and differentiation of subclavian artery stealing blood syndrome
Attention should be paid to the differentiation of vertebral artery type cervical spondylosis, posterior cranial fossa occupying lesions, and Meniere's disease.
