The age of lower extremity arteriosclerosis obliterans is the primary risk factor of PDA, and its incidence increases with age. A survey of arteriosclerosis obliterans of lower limbs published by TASC shows that the annual incidence rate of arteriosclerosis obliterans of lower limbs in men aged 40-50 years is 0.3%, and it increases to 1[3 1] for the elderly over 75 years old. According to a population survey in Australia, the incidence of arteriosclerosis obliterans in men aged 65-69 is 10.6%, while that in men aged 75-79 is as high as 23.3%. According to a population survey conducted by Framingham Cardiovascular Research Center, 20% of symptomatic PDA patients with arteriosclerosis obliterans of lower limbs have diabetes. Compared with non-diabetic people, the prevalence of arteriosclerosis obliterans of lower limbs is higher, younger and the course of disease is faster. Smoking does great harm to peripheral blood vessels, twice as much as cardiovascular and cerebrovascular diseases. A survey in the United States found that 80% of PDA patients with arteriosclerosis obliterans of lower limbs smoke. Quitting smoking can improve clinical symptoms and delay the progress of the disease. Hypertension, hyperlipidemia and obesity are also pathogenic factors of PDA in arteriosclerosis obliterans of lower limbs. The early symptoms of PDA in arteriosclerosis obliterans of lower limbs are intermittent claudication, weakening or disappearance of distal arterial pulsation, while in arteriosclerosis obliterans of lower limbs, rest pain, obvious decrease of skin temperature, cyanosis, toe ulcer, gangrene and so on may occur in the later stage. The existence and severity of symptoms of arteriosclerosis obliterans of lower limbs are influenced by many factors, such as the speed of disease progression, collateral circulation and individual tolerance. The diagnosis of intractable diseases only depends on the clinical manifestations of arteriosclerosis obliterans of lower limbs. Arteriosclerosis obliterans of lower limbs is sensitive and objective, easy to miss diagnosis and treatment, and has poor maneuverability. Meijer W et al. showed that only 10%-20% PDA patients with arteriosclerosis obliterans of lower limbs had clinical symptoms. For example, patients with lower extremity arteriosclerosis obliterans complicated with diabetes mellitus, due to the insensitivity of patients with lower extremity arteriosclerosis obliterans in the nervous system, the blood supply of lower extremity arteries in some patients with lower extremity arteriosclerosis obliterans has been seriously insufficient, and the clinical symptoms of lower extremity arteriosclerosis obliterans are mild or even lacking.
Rutherford et al. introduced standardized treadmill test and lower extremity arteriosclerosis obliterans classification in parallel, which enhanced the objectivity of clinical evaluation of Dt and made the treatment results of various clinical lower extremity arteriosclerosis obliterans more comparable. Atherosclerosis obliterans of the lower extremity Class O: no clinical symptoms, normal treadmill test or reactive congestion test, no hemodynamic manifestations of arterial obstruction, arteriosclerosis obliterans of the lower extremity 1 Class: mild intermittent claudication, complete treadmill test, restless pulse pressure after exercise >; 50mmHg, but about 20 mmhg lower than the rest: arteriosclerosis obliterans of lower limbs grade 2: 10 degree intermittent claudication between I and 3; 3. Severe intermittent claudication, unable to complete treadmill test, and increased ankle arterial pressure after exercise.
Rutherford's classification of lower extremity arteriosclerosis obliterans is sensitive, accurate and objective, but the operation of lower extremity arteriosclerosis obliterans is complicated, which is not suitable for large-scale screening of lower extremity arteriosclerosis obliterans. Ankle-brachial index (ABI) is a simple and effective index to reflect the hemodynamic changes of arteriosclerosis obliterans of lower limbs. Atherosclerosis obliterans of lower limbs is the ratio of brachial artery systolic blood pressure to dorsalis pedis artery systolic blood pressure. It was first proposed by Strandness DE Jr in 1 10 1 for the clinical diagnosis of arteriosclerosis obliterans of lower limbs, and has been continuously improved since then. Fox FGR 1 1988 has formulated a detailed diagnostic standard 11]: greater than1. Lower extremity arteriosclerosis obliterans 1, lower extremity arteries are normal, but the elasticity of large and medium arteries is reduced; Atherosclerosis obliterans of lower extremity is 0.9~ 1. 1 as normal; Arteriosclerosis obliterans of lower limbs (O.7-0.89) is a mild to moderate arteriosclerotic stenosis. Clinically, arteriosclerosis obliterans of lower limbs can be accompanied by intermittent claudication or arteriosclerosis obliterans of lower limbs without any symptoms. Lower extremity arteriosclerosis obliterans less than 0.7 indicates moderate to severe stenosis, and most patients with lower extremity arteriosclerosis obliterans have intermittent claudication or resting pain. If the ABI value of lower extremity arteriosclerosis obliterans obviously drops more than 0. 15, it means that the arterial stenosis degree of lower extremity arteriosclerosis obliterans exceeds 50%, and the lumen stenosis degree of lower extremity arteriosclerosis obliterans often indicates the possibility of sudden thrombosis. 1 12 1 lower extremity arteriosclerosis obliterans However, the ABI detection of lower extremity arteriosclerosis obliterans also has certain limitations, and the reference value of ABI will be affected by local atherosclerosis or postoperative hemodynamic fluctuations of lower extremity arteriosclerosis obliterans. Treating arteriosclerosis obliterans of lower limbs with antihypertensive, lipid-lowering and antiplatelet aggregation can only delay the progress of arteriosclerosis obliterans of lower limbs, but can't fundamentally eliminate the stenosis and occlusion of arteriosclerosis obliterans of lower limbs. Surgical endarterectomy, artificial blood vessel replacement and bypass reconstruction of arteriosclerosis obliterans of lower limbs are traumatic and risky, especially not suitable for patients with arteriosclerosis obliterans of lower limbs complicated with severe cardiovascular and cerebrovascular diseases and diabetes. Endovascular interventional therapy for arteriosclerosis obliterans of lower limbs has the advantages of minimally invasive, simple operation, exact curative effect and repeatable operation, and is the development direction of diagnosis and treatment of vascular diseases.
1. Percutaneous balloon angioplasty for arteriosclerosis obliterans of lower limbs
PTA is a great progress in the treatment of vascular diseases. At present, BaHoon angioplasty is a mature technology. The main mechanism of PTA vasodilation in arteriosclerosis obliterans of lower limbs is that balloon dilation separates the stenotic and sclerotic intima, and at the same time destroys the tough layer of smooth muscle and collagen fiber of intima, which leads to the rupture of atherosclerotic plaque and the stretching of intima. Therefore, balloon vasodilation is a method to treat arteriosclerosis obliterans of lower limbs caused by mechanical dilation. In order to obtain good PFA effect, the rupture depth of blood vessel wall must reach the elastic layer of media. A group of femoral artery and popliteal artery interventional therapy reported by Capek et al. in 1989.
The cumulative patency rates of 1 year, 3-year and 5-year were 8 1%, 6 1% and 58% respectively [171]. Schwarten et al. reported in 1988 144 cases of lower extremity arteriosclerosis obliterans, the success rate of interventional therapy was 97%, and the success rate of limb salvage was 86% after two years of follow-up. " Capek also found in the treatment of lower extremity arteriosclerosis obliterans that the pulse of dorsalis pedis artery is the key factor for the success of PTA treatment of femoral artery, so he thought that "interventional therapy of femoral artery PTA for lower extremity arteriosclerosis obliterans below popliteal artery can improve the long-term patency rate of PTA technique for lower extremity arteriosclerosis obliterans".
2. Stent for arteriosclerosis obliterans of lower limbs.
PTA can cause tearing and elastic retraction of vascular interlayer in arteriosclerosis obliterans of lower limbs. Stent implantation overcomes two main defects of PTA by squeezing plaque and wall, which is a new method for endovascular treatment of arteriosclerosis obliterans of lower limbs. Palmaz et al. used randomized prospective trial (RPT) to find that there were significant differences between the two groups of patients with lower extremity arteriosclerosis obliterans treated with stent implantation and PTA alone. The results of two-year follow-up showed that the patency rate of arteriosclerosis obliterans in the former was 65,438+00%-65,438+05%. According to the need of balloon dilatation, endovascular stents for arteriosclerosis obliterans of lower limbs can be divided into balloon dilatation tents and self-expanding stents. In the early 1990s, FDA approved the use of Balloon Stent (Palmaz) in the treatment of aortic stenosis in arteriosclerosis obliterans of lower limbs. This kind of stent has strong rigidity and can support long stenosis and occlusion. Self-expanding stent is widely used in arteriosclerosis obliterans of lower limbs in recent years. It has the advantages of good flexibility, ability to pass through twisted lesions, good adhesion to the wall of the tube, and easy to be compressed and tortuous, and is suitable for long-segment lesions. Self-expanding stent for wound in oil cavity is a relatively new peripheral stent for arteriosclerosis obliterans of lower limbs, which has ideal flexibility, coverage and supporting force, and is especially suitable for releasing arteriosclerosis obliterans of lower limbs in joints. The long-term effect of femoral artery stent implantation in lower extremity arteriosclerosis obliterans is limited, mainly due to intimal hyperplasia of lower extremity arteriosclerosis obliterans leading to lumen re-occlusion. At present, peripheral interventional therapy with covered stent has been reported, but the long-term patency rate has not been significantly improved 120 1.
3. Rotary plaque incision for the treatment of arteriosclerosis obliterans of lower limbs.
The technology of arteriosclerosis obliterans of lower limbs began in the mid-1980s. Its principle is to grind the atherosclerotic plaque into tiny particles by a high-speed rotating device, and the crushed atherosclerotic plaque fragments and particles can be swallowed up by the reticuloendothelial system, thus not causing distal vascular occlusion. Atherosclerotic occlusive disease of lower limbs can theoretically remove calcified hard plaque on blood vessel wall without damaging blood vessel wall. This operation has several advantages: the success rate of interventional surgery for arteriosclerosis obliterans of lower limbs (1) is high; Lower extremity arteriosclerosis obliterans (2) has a wide range of therapeutic indications; And the operation can be repeated. There are many kinds of PAC catheters used for arteriosclerosis obliterans of lower limbs, including Kensey dynamic angioplasty catheter, Simpson catheter and Auth Rotablator.
A group of 46 patients with arteriosclerosis obliterans of lower limbs complicated with femoral and popliteal artery occlusion, the lesion length was 2-20cm. The clinical results of Kensey catheter in the treatment of lower extremity arteriosclerosis obliterans showed that the success rate was 87%, including 4 cases of lower extremity arteriosclerosis obliterans perforation but no further surgical treatment was needed. The half-year patency rate of arteriosclerosis obliterans of lower limbs was 72%, and the patency rate of arteriosclerosis obliterans of lower limbs was 70% 1 year. However, it has also been reported that compared with the previous PTA reports, although the initial success rate of this technique is higher, the short-term and uncertain curative effect of arteriosclerosis obliterans of lower limbs is far lower than that of PTA, which may be due to the mechanical stimulation of the drill vibration on the blood vessel wall.
4. Other interventional treatment techniques for arteriosclerosis obliterans of lower limbs.
Ultrasound and laser angioplasty for arteriosclerosis obliterans of lower limbs are the new focus of peripheral interventional techniques for arteriosclerosis obliterans of lower limbs in recent years, which can open long-segment occlusive lesions of smaller arteries, especially for the treatment of occlusive lesions below popliteal artery of diabetes mellitus.