Why peripheral artery “blood shortage”
The clinical term for vascular diseases outside the cardiovascular system is peripheral vascular disease. Various causes of peripheral artery stenosis, embolism, occlusion, etc., can cause a series of symptoms such as cold limbs, no pulse, pain; in severe cases, it can cause limb necrosis, amputation, and even life-threatening. These diseases are common: atherosclerotic occlusive disease, thrombo-occlusive vasculitis, Raynaud’s disease or Raynaud’s sign, diabetic vasculopathy (such as diabetic foot), etc.
Peripheral arterial ischemic diseases are locally characterized by pain, skin color and temperature changes, limb swelling or atrophy, ulcers and gangrene as the main clinical manifestations.
1. Pain: including locomotor pain and persistent pain. Locomotor pain refers to the discomfort symptoms that accompany movement, including tiredness, dull pain, tension and pressure, spasmodic pain or sharp pain at the site of insufficient blood supply.
Motor pain occurring in the lower extremities is also called intermittent claudication, which is manifested by the patient walking at a certain speed for a certain distance and then experiencing soreness and twitching pain in a certain part of the lower extremity, forcing him to stop walking, and after resting for 1~5 minutes the symptoms are relieved or disappear, and then the same symptoms appear again when walking again. This is the early clinical manifestation of arterial occlusive disease. It is generally believed to be caused by insufficient blood supply to the arteries and stimulation of local muscles and peripheral nerves by metabolites.
Persistent pain, i.e. resting pain, refers to the pain produced by the limb at rest, which persists, especially at night. It is characterized by persistent dull pain with intermittent sharp stabbing pain, which may radiate to the distal extremities of the limbs and is accompanied by numbness, sympathetic coldness or burning, ankylosis, and pins and needles-like sensory abnormalities. The patient often sits on his knees to relieve the pain. When the limb is dystrophic ulcer or gangrene due to ischemia, there may also be persistent and severe localized pain. The pain is caused by arterial blockage, degeneration of peripheral nerves due to hypoxia, nerve fibrosis, and even nerve degeneration. The occurrence of persistent pain often indicates that the degree of lesion and ischemia has increased and is close to the degree of loss of compensation.
2, skin color, skin temperature changes: skin color and temperature depends on the speed of blood flow in the skin vessels, flow and blood oxygenation. With poor blood flow and insufficient arterial blood supply, the extremities will appear pale and cold. If blood stasis stays and blood return is blocked, local venous stasis occurs and the skin color is purple or skin temperature is elevated.
3, limb swelling or atrophy: long-term insufficient blood supply, limb loss of nourishment, or because of long-term knee sitting, limb waste, can make muscle atrophy, limb thinning. Conversely, if due to long-term venous blood return obstruction, there will be tissue edema, swelling and thickening of the limb.
4, ulcers or gangrene: arterial ischemia for a long time, no blood supply to the limb, there are gangrenous lesions, the gangrenous area due to liquid evaporation and absorption and the formation of dry gangrene; such as concurrent infection is the formation of wet gangrene, localized pus, a bad smell. Necrotic tissue is shed to form ulcers, which are more difficult to heal.
In addition, in the acute phase, patients often have systemic symptoms such as fever, bone pain, fatigue and discomfort.
Traditional treatment methods are poor.
The clinical treatment of peripheral arterial ischemic disease is divided into three parts: Chinese and Western drug therapy, surgical treatment and interventional treatment.
The indications for Chinese and Western drug therapy are acute thrombosis or embolism, chronic insufficiency of blood supply and arterial spasm diseases, including thrombolysis, anticoagulation, decongestion, dilation, fibrinogenesis, and inhibition of platelet adhesion and aggregation, but the efficacy is limited.
Surgical treatment includes vascular anastomosis and repair, vascular bypass surgery, venous valve repair, and amputation required for peripheral vascular injury, which can play a role in shortening the course of treatment, improving the efficacy, and reducing the rate of disability and mortality when combined with drugs. However, the indications for surgical treatment are narrow, and there are problems such as surgical complications and postoperative restenosis rates of up to 30%, and little effect on small arteries and capillaries in the distal limbs.
Compared with surgical procedures, interventional vascular therapy has the advantages of less damage, lower complication rate and mortality rate, and faster patient recovery, such as percutaneous transluminal balloon catheter angioplasty, endoluminal vascular stent implantation, atherosclerotic plaque spinning, laser angioplasty, and vascular embolization. However, interventional treatment also has problems such as little effect on small arteries and capillaries in the distal part of the limb and postoperative restenosis.
Spinal Cord Electrical Stimulation Ignites New Hope
In recent years, spinal cord electrical stimulation (SCS) has opened up a new therapeutic field for peripheral arterial vascular ischemic diseases for which conventional treatment methods are ineffective.
By stimulating the spinal cord area innervating the ischemic limb, SCS can, on the one hand, inhibit the sympathetic efferent impulses and dilate the small arteries and micro-arteries in the ischemic area, and at the same time, promote the regeneration of capillaries and the establishment of collateral circulation in the ischemic area, thus effectively improving ischemia, promoting tissue healing and delaying amputation. On the other hand, by stimulating the thick afferent nerve fibers, the pain “gate” is closed and the pain of the ischemic limb is effectively relieved.
It has been widely reported in the literature that SCS can achieve good results in severe atherosclerotic occlusive disease, thrombo-occlusive vasculitis, Raynaud’s disease or Raynaud’s sign, diabetic vasculopathy and other limb ischemia and ulcers, even if other conservative treatments and sympathectomy are ineffective, and even interventional vascular therapy and surgery are not effective. In Europe, nearly 10,000 patients are treated with SCS every year, which has greatly reduced the rate of amputation and given new hope to many diabetic foot patients.
In China, this treatment has just started, and only a few hospitals such as Nanjing and Beijing are carrying out it. Special reminder is needed: (1) Patients with ulcer area less than 3cm2 are suitable for SCS treatment. (2) Pain relief >50% and transcutaneous partial pressure of oxygen (TcPO2) elevation >15% as the indication of passing the test. (3) Those with TcPO2<10mmHg before treatment have poor prognosis. (4) The ulcer or toe amputation wound can heal if TcPO2 is elevated to 30mmHg after treatment. (5) SCS treatment of POAD can relieve pain, improve blood supply and delay amputation, but, like conventional methods, cannot change the final prognosis.