[Aortic stent: the anesthesiologist's point of view]

The treatment of thoracic or abdominal aorta aneurysms with endoprostheses or aortic stents consists of placing the stents within the aorta to exclude the aneurysm, followed by inflation of a balloon inserted through the vessel in order to fix the stent to the vascular walls. The procedure is minimally invasive, causes little pain, and is performed by femoral arteriotomy or puncture. Absolute immobility of the lower limbs is required if lesions are to be avoided and the duration can not be foreseen. Patients are usually elderly, have severe vascular disease, hypertension, ischemic heart disease and sometimes also have renal dysfunction that may deteriorate with the use of iodine contrast media. Epidural anesthesia is preferred for placement of an abdominal stent, with general anesthesia used if epidural anesthesia is contraindicated. Surgery is performed in an angio-radiologic operating theater that is specially prepared for emergency laparotomy or thoracotomy. General anesthesia is used for thoracic aneurysms. When the endoprosthesis is implanted, it is important to prevent distal migration of the stent caused by heart beat and arterial pressure generated by the root of the aorta. A sympathic block provides adequate mean blood pressure (approximately 70-80 mmHg) for preventing migration. Five minutes before release of the stent, esmolol (0.5 mg/kg) is given along with nitroglycerine (titrated to dose-response) in perfusion, and upon release of the stent and sufflation of the balloon, a Valsalva maneuver is carried out obtain a heart rate of 40 to 50 beats/min and a mean arterial pressure of 40 to 45 mmHg. Postoperative recovery occurs in a special observation ward in the first few hours after surgery, with strict monitoring of diuresis and hydration. Analgesic requirements are minimal and intravenous metamizol or ketorolac are adequate. In conclusion, stent implant is a complex procedure in patients with severe associated disease who require strict and full monitoring during surgery and in the first few hours afterwards.