Cyanosis or necrosis of the fingers

Introduction Finger cyanosis or necrosis is the ischemic symptom of upper limbs in the clinical manifestations of subclavian steal syndrome. The common ones are intermittent exercise, weak upper limbs, pain and paresthesia, and very few causes finger cyanosis or necrosis.

Cause

Cause:

1. "Stealing 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, blood can flow back from the head to the heart or to the upper limbs. "The subclavian artery 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 right subclavian artery of the acute occlusion dog is proximal to the heart, it causes retrograde blood flow to the right vertebral artery. This blood flow retrograde depends on the blood pressure difference between the systemic blood pressure and the right vertebral-subclavian artery junction. When the difference increases, it causes blood flow retrograde (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. There are many physiological or anatomical factors in the vertebral artery blood flow retrograde, the most important of which is the degree of subclavian artery stenosis. In patients with blood stealing, the systolic pressure difference between the two upper limbs is often less than that of blood stealing. Bigger. In addition, it depends on the situation of the side branch cycle.

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 into: 1 vertebral artery-vertebral artery (66%); 2 carotid-basal artery (26%); 3 external carotid artery-vertebral artery (6%); 4 carotid artery - subclavian artery (2%) stealing blood. He also pointed out that only the external carotid artery-vertebral artery shunt occurs when there is occlusive damage to the internal carotid artery.

4. The meaning of collateral circulation when "stolen blood"

When the subclavian artery steals blood, the presence of a collateral circulation is a response to occlusion. Cerebral angiography commonly has the following five collateral circulations: 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 ipsilateral cervical ascending artery and vertebral artery Branches; 5 occipital branches of the external carotid artery and the musculoskeletal 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. Affect blood circulation. An angiographic observation of 42 patients with this syndrome found that in patients with vertebrobasilar insufficiency, the blood flow to the posterior cerebral artery originated from the internal carotid artery (normally from the basilar artery); the posterior cerebral artery was embryo The type (ie, the artery is straight from the internal carotid artery to the rear) and the junction between the posterior communicating artery and the posterior cerebral artery has an angle (indicating dysplasia), which is higher than that in patients without vertebral-based blood supply.

an examination

Related inspection

Pulse blood pressure

diagnosis:

1. The average male is more common than the female, and the age is more than 50 years old. More common to the left side of the damage. This may be due to the large angle of the left subclavian artery at the beginning of the aorta, which is susceptible to blood flow and causes atherosclerosis. This syndrome may have neurological symptoms of vertebral-basal arterial insufficiency and ischemic symptoms of upper limbs. Symptoms of carotid insufficiency are rare and are only seen in patients with dry or bilateral subclavian artery stenosis.

2. Symptoms of vertebral-basal arterial insufficiency: The most common symptoms are dizziness, limb paralysis, paresthesia, bilateral visual impairment, ataxia, diplopia, syncope, and rare intermittent claudication, difficulty in pronunciation Dysphagia, tinnitus, convulsions, headaches and mental disorders. A few people may have a "drop attack", which shows that there is no aura, sudden onset of lower limb muscle loss and fall, without consciousness disorder, and can quickly recover, may be due to ischemia of the medullary vertebral body. Generally, patients with this syndrome will not cause permanent neurological damage.

3. Ischemic symptoms of upper limbs: Commonly, the intermittent movement is ineffective, the upper limbs are weak, the pain and paresthesia, and very few cause finger cyanosis or necrosis.

4. General signs

(1) Blood pressure: The blood pressure of the upper limbs of the affected side is reduced, and 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 point of view of angiography, degree of symptoms and frequency of attacks, the difference in blood pressure is independent of the degree of stenosis of the damaged blood vessel.

(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 affected side of the pulse is late, which is due to the pulse wave from the contralateral vertebral artery to the affected side of the vertebral artery, and then to the wrist, the distance is far.

(3) vascular murmurs on the supraclavicular region: most audible and systolic murmurs, and the affected limbs may aggravate the murmur.

Such as: 1 history of vertebral-basal arterial insufficiency, especially at the same time there are ischemic symptoms of the upper limbs. 2 examination found that the systolic blood pressure difference between the two arms is above 20mmHg; 3 pulse is late; 4 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.

Differential diagnosis

Differential diagnosis of finger cyanosis or necrosis:

1, purple red palm: purple red palm: If the palm color black red black red, purple red palm, we must consider serious heart disease, such as coronary heart disease, asthma, etc., when inflammation is not controlled to the development of sepsis The palm color will also return to the microcirculation and cause blood purple. At this time, the danger signal should be improved early.

2, the hand skin is purple: the skin is purple is the type of purple hair.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.