الفهرس 
Chapter 1 : Anesthetic management of endovascularOnly 14 pages are availabe for public view
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Abstract
The patient who presents for vascular surgery is a high risk surgical candidate and is typically characterized by a history of atherosclerosis, hypertension, COPD, coronary artery disease or diabetes mellitus . So, endovascular interventions offer major advantages of being minimally invasive techniques with less stress, less morbidity, shorter hospital stay, faster return to normal life style and the possibility of surgical correction for those medically compromised patients who are otherwise too ill for open surgical repair because of the associated risks.1
Endovascular aortic repair for aneurysms of abdominal or thoracic aorta should include preoperative assessment of cardiac condition according to ACC/AHA guidelines for noncardiac surgery. Functional capacity of the patient is assessed with optimization of associated medical conditions preoperatively in elective cases.2
General, regional or local infiltration can be used in EVAR depending on the complexity of aneurysmal anatomy and premorbid state of the patient where local anesthesia can be used for simple infrarenal abdominal aneurysms.3
Regional anesthesia has the advantages of blocking stress response, the patient can be used as a monitor for dyspnea or angina, improved graft blood flow and postoperative analgesia
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with the disadvantages of patient discomfort in long duration procedures, respiratory depression from sedation or high level and the risk associated with thrombolytic therapy.4
General anesthesia can be used to control airway and secure it against aspiration . Also, it has the advantage of easy control of hemodynamics as induced hypotension is required during deployment of the stent graft.5
Post operative complications include endoleaks, acute kidney injury, spinal cord ischemia , misdeployment of the graft, myocardial infarction , embolic events, rupture of the aneurysm and post implantation syndrome.6,7
Interventional neuroradiology is used for treatment of many cerebrovascular diseases including embolization of brain A.V malformations , coil embolization of intracranial aneurysms, angioplasty for cerebral vasospasms, thrombolysis of acute thromboembolic stroke and embolization of tumours.8
Digital subtraction angiography in hybrid theatre exposes anesthesiologists to great risk of radiation which necessitates optimal protection including use of lead aprons, thyroid shield, movable lead glass screens and keeping a distance away from the source of radiation .9
General anesthesia for endovascular neurosurgery has the advantage of minimizing motion artifact thus improve image
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quality. Total intravenous anesthetic technique or combination with low inspired concenterations of inhalational can optimize rapid neurological evaluation postoperatively. General anesthesia gives the advantage of easy control of paco2 through ventilation as mild hypocapnea can be used in case of increased intracranial tension . Also, easy control of blood pressure can be achieved to produce induced hypotension in case of A.V malformations before glue injection or produce induced hypertension in case of acute arterial occlusion or vasospasm.10
Monitored anesthetic care with conscious I.V sedation allows continual assessment of neurological functions during the procedure but with the potential of upper airway obstruction. It has the advantage of no hemodynamic changes associated with intubation or emergence from general anesthesia but with poor tolerance of induced hypotension in awake patient .11
The post operative complications include intracranial hemorrhage, displacement of coil, thromboembolic stroke or arterial vasospasm. The patient is transported to I.C.U postoperatively with good monitoring of arterial blood pressure and anticoagulation with heparin is continued up to hours after the procedure to prevent thromboembolism but in case of intracranial hemorrhage, it must be reversed with protamine to control bleeding.12,13
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Transcatheter Aortic Valve Implantation is used for high-risk patients with aortic stenosis where general, thoracic epidural or local anesthesia can be used according to the used approach.14
General anesthesia has the advantages of good hemodynamic stability, adequate attenuation of stress response and early diagnosis and treatment of possible complications through the use of transesophageal echocardiography but with potentially increased respiratory complications.15
Thoracic epidural anesthesia can be used with advantages of postoperative analgesia and ability to perform a fast track but hypotension must be prevented for fear of myocardial ischemia. Also, Use of heparin intraoperatively and postoperative dual antiplatelet therapy increase the risk of epidural hematoma.16
Local infiltration can be used for transfemoral approach but it is not suitable for transapical approach. Intravenous sedation with remifentanil infusion alone or combined with propofol can be used. Invasiveness of the procedure and the difficulty to achieve stable hemodynamics are the major limitations.17
During prosthesis implantation, Rapid ventricular pacing is used to induce temporary reversible cessation of cardiac output during aortic valve deployment to prevent malposition and embolization of the prosthesis. Bolus of vasopressor prior to or
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immediately after the rapid pacing episode can maintain coronary perfusion pressure and prevent ischemia of hypertrophied myocardium.18
Postoperative complications include vascular injuries, arrhythmias, renal impairment, neurological complications, cardiac tamponade and left main coronary artery occlusion.