Abdominal aortic aneurism

Patients Aortic Aneurysm

Abdominal aortic aneurysm (AAA): refers to when the diameter of abdominal aorta expands to 1.5 times the normal diameter, and is the most common artery dilation disease. The rupture of abdominal aortic aneurysm could result in hemorrhage, threatening life of the patient. Once ruptured the mortality rate can be as high as 70-90%, however with elective surgery the mortality rate can be reduce to below 5%. Therefore, early diagnosis and treatment are very important.

Abdominal Aortic Aneurysm Symptoms

  1. Pulsatile abdominal masses: The aneurysm can be identified with physical examinations, as a round tumor located at the umbilical, or the upper left of the umbilical, the mass can be found pulsating at a rate that is consistent with the heartbeat.
  2. Pain: The aneurysm can compress and erode vertical body, causing pain at the nerve root of the abdomen and/or the lower back. Sudden sharp abdominal pain is often the precursor of rapid expansion or even rupture of the aneurysm.
  3. Sense of Compression: Compression of surrounding organs can result into associated symptoms, such as upper abdominal fullness, urinary system obstruction, etc.
  4. Embolism: The blood clot in the aneurism often falls off, and rushes to the peripheral circulation systems, resulting in arterial embolism at the lower extremity, leading to limb ischemia and necrosis
  5. Hemorrhage: The most serious clinical threat of this disease, manifested as sudden severe abdominal pain, hemorrhagic shock and pulsatile abdominal mass.
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Diagnosis

  1. Ultrasound: The ultrasound could detect abdominal aortic aneurysms with a diameter of greater than 3 cm, and whether there are plaques or blood clots present.
  2. CT (computer tomography): Plain and enhanced CT scan could accurately display the shape of the aneurysm and adjacent relationship with surrounding organs. The scan could also help physicians to judge whether there are anatomical abnormalities, and identify whether there are other abdominal diseases. The Spiral CT three-dimensional reconstruction technology (3DCTA) can accurately display the three dimensional morphology, size and degree of seriousness of the affected abdominal aortic branches, as well as measure the parameter of the various parts of the aneurysm.
  3. MR angiography: Angiography can show the location, size and shape of aneurysm without the need for contrasting agent, and can provide vivid images of the aneurysm. Angiograph can provide high diagnostic value for subacute and chronic hematoma caused by aneurysm rupture.
  4. DSA (digital subtraction angioplasty): DSA can provide important value in the diagnosis of thoracoabdominal aortic aneurysm, multiple aneurysm and aortic dissection. However the true size of the aneurysm may not be displayed when there is a large number of blood clots within the aneurysm.
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Therapeutic solutions: Endovascular Aortic Repair

Endovascular Aortic Repair (EVAR) is an alternative to open surgery and has the advantage of less trauma, faster recovery, fewer complications and fewer contra-indications. During EVAR, under the constant monitoring of DSA, a folded metal scaffold covered with artificial vascular membrane is delivered into the abdominal aorta through the bilateral common femoral artery approach, and then placed into the aneurysm cavity according to the stent positioning set before operation. The stent is fixed onto the artery wall near and distal to the aneurysm by using the self-expanding property of the metal scaffold and the barb on the bare segment of the scaffold (to withstand the impact of high pressure blood flow on the aortic wall). Then, the aortic wall of the aneurysm and stent membrane form blood thrombosis and structure, this achieves the purpose of isolating the aneurysm and treating the disease.

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Aortic Dissection Symptoms

Pain: The onset of acute aortic dissection is sudden, and greater than 90% of patients experience sudden severe tearing or knife like pain in the anterior chest, back or the abdomen, and the pain can be transferred along the aorta towards the upper or lower abdomen.

Sudden Death: When the ascending aorta is ruptured, acute cardiac tamponade could occur due to blood entering the pericardial cavity.

Neurological Symptoms: When aortic dissection affects the brachiocephalic artery, cerebral blood supply disorders could occur, such as syncope, coma, hemiplegia, etc.

Abdominal Pain: When dissection affects abdominal parenchymal organs.

Lower limb ischemia: Symptoms involve the traditional 5 Ps of acute ischemia in a limb (i.e., pain, paresthesia, pallor, pulselessness, poikilothermia).

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Therapeutic solutions

After diagnosis of thoracic aortic aneurysm, active treatment including surgical thoracotomy and endovascular repair should be carried out.

  1. Open Surgery: Total aortic arch replacement with the elephant trunk technique. Total aortic arch replacement, refers to the use of artificial blood vessels to replace the diseased thoracic aorta. The actual surgical procedure and post-operative results vary with the anatomical location of the thoracic aorta. The main complications of the procedure were bleeding, severe arrhythmia, coronary insufficiency, and central nervous system complications. The 1-year and 5-year survival rates were 80% - 90% and 60% - 80%, respectively.
  2. Minimally Invasive: Thoracic Endovascular Aortic Repair TEVAR: TEVAR is an alternative to open surgery and has the advantage of less trauma, faster recovery, fewer complications and fewer contra-indications. During TEVAR, under the constant monitoring of DSA, a folded metal scaffold covered with artificial vascular membrane are inserted into the aorta, With the continuous advances in the endovascular devices, some thoracic aortic aneurysms involving supra-aortic arch branches can also be repaired via endovascular repair.
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