ANESTHETIC TECHNIQUE AND PERIOPERATIVE RI SKS IN ENDOVASCULAR TREATMENT OF AORTIC-ANEURYSMS

Surgical treatment of aortic aneurysms carries significant cardiovascu lar risks. Transvascular insertion of endoluminal prostheses is a new, minimally invasive treatment for aortic aneurysms. The pathophysiolog y of this novel procedure, risks and benefits of different anaesthetic techniques, and typical complications need to be defined. Methods. Wi th their informed, written consent, 19 male patients aged 48-83 years of ASA physical status III and IV with infrarenal (n=18) or thoracic ( n=1) aortic aneurysms underwent 23 stenting procedures under general e ndotracheal (n=9), epidural (n=8), or local anaesthesia with sedation (n=6). Intra-anaesthetic haemodynamics, indicators of postoperative (p .o.) oxygenation and systemic inflammatory response, and perioperative complications were analysed retrospectively and compared between anae sthetic regimens. Results. Groups were well matched with regard to mor phometry and preoperative risk profiles (Table 1). The use of pulmonar y artery pressure monitoring, incidence of intraoperative hypotensive episodes, and p.o. intensive care was more frequent with general anaes thesia. Groups did not differ in total duration of anaesthesia care, i ncidence and duration of intraoperative hypertensive, brady-, or tachy cardic periods, incidence of arterial oxygen desaturation, use of vaso pressors, colloid volume replacements, or antihypertensives (Table 2). Postoperatively, all groups showed a similar, significant systemic in flammatory response, i.e., rapidly spiking temperature (p.o. evening: mean peak 38.5 +/- 1.0 degrees C), leucocytosis, and rise of acute-pha se proteins without bacteraemia (Table 3). During this period, despite supplemental oxygen, pulse oximetry revealed temporary arterial desat uration in 13 of 18 patients (70%) (Table 3). In 3 patients, hyperpyre xia was associated with intermittent tachyarrhythmias (n=3) and angina pectoris (n=1). There was no conversion to open aortic surgery, perio perative myocardial infarction, or death. Conclusions. Regional and lo cal anaesthesia with sedation are feasible alternatives to general end otracheal anaesthesia for minimally invasive treatment of aortic aneur ysms by endovascular stenting. However, invasive monitoring and close postoperative monitoring are strongly recommended with either method. Specific perioperative risks in patients with limited cardiovascular o r pulmonary reserve are introduced by the abacterial systemic inflamma tory response to aortic stent implantation. Hyperpyrexia increases myo cardial and whole-body oxygen consumption, and can precipitate tachyar rhythmias. Hyperfibrinogenaemia may increase the risk of postoperative arterial and venous thromboses. Close monitoring of vital parameters and prophylactic measures, including oxygen supplementation, low-dose anticoagulation, antipyretics, and fluid replacement are warranted unt il this syndrome resolves.