Popliteal aneurysm
Introduction
Introduction to iliac aneurysms Ankle aneurysm (poplitealaneurysm) is one of the more common aneurysms in peripheral vascular aneurysms, mostly atherosclerotic tumors, followed by invasive aneurysms. Formed by the expansion of the radial artery. Often bilateral onset, and more often combined with other aneurysms. Because of the often associated thrombosis in an aneurysm, thrombus shedding causes distal arterial embolization, which can lead to limb ischemia. basic knowledge The proportion of illness: 0.003% Susceptible people: no specific population Mode of infection: non-infectious Complications: arterial embolism
Cause
Cause of iliac aneurysm
(1) Causes of the disease
1. Arteriosclerosis: endometrial ulcers, local dystrophies of the wall, degeneration, and fragility to form an aneurysm.
2. Trauma: Traumatic iliac aneurysms are mostly pseudoaneurysms, which may be caused by penetrating injuries such as fractures or shrapnel near the knee joint, or by blunt trauma of the brachial artery caused by external force. In addition, iatrogenic trauma has gradually increased, such as the use of arthroscopy for meniscus resection caused by iliac aneurysms, these factors cause brachial artery wall damage, weak and form an aneurysm. Traumatic aneurysms are mostly young patients.
3. Exercise: The constant flexion and extension of the knee joint can also cause the blood vessels to expand and form an aneurysm. The radial artery passes between the adductor muscle tube and the posterior axillary ligament of the knee, which can cause local external pressure stenosis of the radial artery, and an aneurysm can be formed at the distal end of the stenosis.
4. Infection: including endogenous infections (such as sepsis or direct spread of infection) and exogenous infections, can cause weak and necrosis of the arterial wall, and eventually form an aneurysm.
5. Radial artery compression syndrome: occurs in young people, due to abnormal muscles, fiber bundles and other compression of the radial artery in the armpit, due to repeated chronic injury to the radial artery, can cause degenerative degeneration of the radial artery, and in the compression site Causes the development of atherosclerosis and arterial stenosis, thrombosis or intimal hyperplasia, and the proximal brachial artery pressure increases, leading to the expansion of the arteries after stenosis.
6. Other causes: Others such as degenerative degeneration of arterial membrane, nodular arteritis, Behcet's syndrome can cause iliac aneurysms, but it is rare.
(two) pathogenesis
1. Pathogenesis: no muscle protection around the radial artery and often in the stretched state with knee joint activity, so it is prone to atherosclerosis, under the influence of age, lipid metabolism disorder, smoking, high blood pressure and other factors, arterial porridge The development of sclerotherapy results in degeneration of the wall, local atrophy, fragility, etc. Aneurysms can be formed. Patients with such iliac aneurysms are often over 50 years old, often accompanied by coronary atherosclerotic heart disease. In addition, iliac aneurysms originating from arteriosclerosis Often bilateral, usually associated with aneurysms in other areas, according to statistics, 78% of patients with iliac aneurysms have a second aneurysm, 64% have aortic aneurysm, 47% have bilateral iliac aneurysms, 29.7% at the same time Combined with femoral aneurysm, a male patient was found to have an abdominal aortic aneurysm and a right subclavian aneurysm after surgery for bilateral iliac aneurysms.
Trauma or iatrogenic trauma can cause damage to the wall of the radial artery, weak or cause chronic degenerative degeneration of the radial artery, narrowing the lumen, and causing the narrowed lumen to expand into a tumor when the proximal pressure of the radial artery is increased.
2. Pathology: Most of the iliac aneurysms are true aneurysms. The shape is always slender and spindle-shaped. The tumor and the adjacent vessels are often twisted. The radial artery is thinner than the femoral artery, which is easy to cause stenosis and occlusion. The symptoms of limb ischemia occur; the axillary tissue is tight, and local compression symptoms such as venous return disorder and nerve compression are more likely to occur.
3. Pathological type: According to the part of the iliac artery aneurysm, it can be divided into 3 types:
(1) proximal type: often located in the posterior inner and upper of the armpit, usually the tumor is large, can be multi-cavity, most of the tumor has thrombosis, which can be followed by serious complications.
(2) Middle type: the knee joint is near to the center and extends distally, often in the shape of a shuttle.
(3) distal type: located at the farthest end of the radial artery, the aneurysm is small, not easy to be found, until thrombosis, acute arterial embolism, severe limb ischemia or gangrene.
Prevention
Ankle aneurysm prevention
Change eating habits and lifestyles to improve overall health. Regular exercise, pay attention to diet, if smoking, please quit.
Complication
Ankle aneurysm complications Complications, arterial embolism
Distal embolization of iliac aneurysm and rupture of hemorrhage are the main complications of this disease. Among them, thrombus occlusion in aneurysm or embolization due to laminar thrombus in the tumor cavity, the radial artery is the most common cause of lower limb ischemia, and limp can occur. Resting pain can also cause skin necrosis and gangrene in the lower limbs due to acute complete occlusion.
Symptom
Symptoms of iliac aneurysm Common symptoms Motor dysfunction Joint hard edema intermittent sacral artery pulsation weakened or disappeared acral ulcer skin pale limbs chill
Small and uncomplicated iliac aneurysms are asymptomatic, but complications and symptoms will occur sooner or later. In conservative cases such as Szilagyi, 68% of complications occurred within 5 years, and Vermilion et al. followed 26 cases of iliac aneurysms. The average follow-up time was 3 years, and 31% had limb-threatening complications. The common clinical manifestations are as follows:
1. Axillary pulsatile mass: 48% of patients can detect the mass and provide a complaint. They can not complain of the presence of a mass, mostly obesity, joint stiffness and elderly patients. When examined, the knees are more prone to lumps and masses. It is pulsating, but it can also be pulsating because the tumor is full of blood clots.
2. Foot and calf ischemia: is the most common symptom of iliac aneurysm, which may have intermittent claudication, rest pain, ulcer formation and even gangrene (45% in the former, 38% in the latter three), the cause of limb ischemia It is a thrombus formation in the tumor, the thickening of the wall thrombus can completely block the tumor; there can be secondary thrombosis in the distal branch of the radial artery; due to the activity of the knee joint, the wall thrombus is detached, causing Repeated embolization of the distal segment of the artery.
3. Compression of adjacent tissues: The radial artery is closely adjacent to the iliac vein and the phrenic nerve. When the aneurysm is enlarged, the iliac vein is first compressed, causing reflux obstruction, calf edema, and even thrombosis in the vein (13%, Wychulis). After the tumor is further enlarged, the phrenic nerve (6.4%) can be compressed, causing pain and motor dysfunction.
4. Rupture bleeding: Rarely seen, Evans reported that of the 187 iliac aneurysms, only 4 tumors ruptured, accounting for 2.2%. Makhoul reported 7 reports in 1997, and the rupture rate of iliac aneurysms was less than 5%.
Examine
Aneurysm examination
1. Positive lateral radiograph of the knee: visible soft tissue shadow or calcification around the knee joint.
2. B-ultrasound: to understand the blood pressure of the wall thrombus and the tumor in the tumor.
3. Arteriography: To understand the diameter and blood flow of the aneurysm, especially the condition of the lower extremity artery, but it does not necessarily reflect the whole picture of the aneurysm.
4. CTA: can determine the size of the aneurysm, the wall thrombus, the lower extremity arterial vessels and the relationship with the surrounding tissue, but also to determine whether the contralateral or other sites with aneurysms.
Diagnosis
Diagnostic diagnosis of iliac aneurysms
diagnosis
The body can be seen to have swelling of the axilla, the pulsatile mass is consistent with the heart beat, the proximal type can be found on the inner side and the back of the lower third of the thigh, while the central and distal type can only be found behind the armpit. .
According to the symptoms of limb ischemia and compression, combined with cold, numbness, weakened or disappeared pulse, signs of pulsatile mass in the axilla, and eggshell calcification shadow on X-ray film, B-ultrasound, CT, angiography It is not difficult to establish the diagnosis as seen.
If limb ischemia occurs, there may be pale skin, ulcers or gangrene in the extremities, weak or disappeared pulsation of the brachial artery, signs of coldness in the limbs, such as suspected iliac aneurysms, and the contralateral limbs should also be examined to confirm whether there is a merger. Aneurysms in other areas.
Differential diagnosis
When the tumor thrombosis or occlusion of the tumor cavity, palpation can only touch the substantial, no pulsatile mass, need to be differentiated from axillary lipoma, fibroid, axillary cyst, color Doppler ultrasound can identify The nature of the mass.
