Aspects on preoperative evaluation prior to EVAR of AAA

Abstract: Abdominal Aortic Aneurysms, AAA, is mainly a silent disease that mainly affects elderly males with a history of tobacco use, but when rupture occur most affected dies. Endovascular aneurysm repair (EVAR) has made it possible to treat more fragile and elderly patients with advanced co-morbidities. The benefit of EVAR might be questionable in relation to all cause mortality in some patients. Hence, the need for a proper preoperative evaluation in relation to long term mortality is warranted and the indication for operation should be balanced against the risk of rupture during the patients expected remaining lifetime. The aims of this thesis were to assess (I) cardiovascular predictors, (II) preoperative echocardiographic findings, (III) lung function determinants for all cause long term mortality, and to (IV) compare preoperative evaluation by a vascular physician with a standardized workup protocol. Data from patients undergoing elective standard EVAR for AAA between 1998–2011 at Vascular Center, Malmö, Skåne University Hospital, form the basis of this thesis. Paper I showed that myocardial ischemia on electrocardiogram, ECG, (HR 1.6 95% CI 1.1–2.4) and anemia,(HR 1.5 95% CI 1.0–2.1), were found to be independent predictors for long-term mortality. Paper II showed that severe heart valve disease measured with echocardiography, was prevalent in 8.7% among the EVAR patients and was an independent predictor for 1-year mortality (OR 3.5 95% CI 1.2–10.7). Paper III showed that chronic obstructive pulmonary disease, COPD, grade ≥3 measured with spirometry, or blood gas levels of PaO2 < 8.0 kPa (HR 2.1 95% CI 1.2–3.4), chronic kidney disease, stage ≥3 (HR 1.6 95% CI 1.1–2.2) and age ≥80 years (HR 1.6 95% CI 1.0–2.3), were found to be independently associated with long-term mortality. Paper IV showed that preoperative evaluation by a vascular physician between 2007 and 2011, versus the standardized evaluation protocol between 1998 and 2006, resulted in increased dosage of antihypertensive, platelet aggregation inhibitors and lipid lowering agents with 40%, 24% and 31%, respectively, reduced costs in preoperative patient evaluation (p<0.001), but there was no change in long-term mortality (p=0.24). In conclusion, assessment with preoperative ECG, echocardiography, spirometry, hemoglobin and GFR predicts long term mortality, and strengthens the need of formal evaluation for a better patient selection for elective EVAR of AAA. A preoperative assessment by a vascular physician did not affect mortality but a better pharmacological control of cardiovascular risk factors was obtained.