Is surgery necessary for abdominal aortic aneurysm less than 6 cm in diameter?
ABSTRACT During 8 years of an ultrasound screening programme for abdominal aortic aneurysm (AAA), 8944 people aged 65-80 years were scanned. 356 (4%) had AAA of diameter 3 cm or greater. Under our criteria repair was indicated if the aortic diameter reached 6 cm, if expansion reached 1 cm per year, or if the AAA caused symptoms; 124 patients met these criteria. Among the 8820 screened patients who did not meet the criteria, 1 death (0.4%) was attributed to ruptured aneurysm, although the retroperitoneal haematoma had developed within 5 days of surgery for a colon tumour. The risk of aortic rupture in patients with AAA less than 6 cm diameter with these criteria (0.4%) is lower than that for elective surgery (1-8%). Surgical repair is unnecessary and possibly detrimental in such patients, provided that ultrasound surveillance is undertaken.
- [Show abstract] [Hide abstract]
ABSTRACT: Two methods are available for treatment of aneurysm — open surgery or endovascular aneurysm repair. The first treatment uses synthetic polymeric graft to replace the diseased site, whilst the second involves strengthening the blood vessel wall with an expandable metallic stent. Endovascular aneurysm repair is gaining popularity over open surgery, but the technique is relatively new without long-term follow-up outcome. Pre-clinical evaluations are therefore crucial to minimise possible complications such as endoleaks, stent migration, stent failure and other complications. In this study, the effectiveness of stent geometry in terms of protecting the weak wall of an aneurysm sack from the impact of blood flow was studied. Three dimensional model of a simplified aneurysm model was constructed with a thickness of 2mm throughout. Two already expanded stent geometries were modelled and positioned inside the aneurysm site. Blood flow was simulated across the aneurysm sack using a commercially available fluid dynamics software. The results showed a slight increase in pressure within the aneurysm region under simulated blood flow. When metallic stents were introduced, the pressure at the aneurysm site was reduced. This study confirms the effectiveness of the endovascular aneurysm repair in terms of protecting the blood vessel from a possible rupture.12/2007: pages 398-402;
- [Show abstract] [Hide abstract]
ABSTRACT: Background: The decision of whether to repair small abdominal aortic aneurysms (AAAs), which are those that are less than 5 cm in diameter, remains controversial. Methods: We describe 161 consecutive patients who were seen at a single urban hospital with ruptured AAAs (rAAAs) and in whom aneurysm size was measured with ultrasound scanning, or rarely computed tomography, en route to the operating room. Eleven patients (6.8%) had AAAs that measured less than 5.0 cm. This group was compared with 150 patients who had rAAAs that were more than 5 cm. Results: The mortality rates were similar in both of the groups—70% for small rAAAs versus 66% for large rAAAs. No significant differences were seen between the patients with small and large ruptured aneurysms with respect to the prevalence rates of hypertension (60% vs 50%) or of cardiac disease (20% vs 22%). However, the prevalence rate of obstructive lung disease was significantly different (64% vs 25%; P = .02) as was the rate of diabetes (28% vs 3%; P = .004). Five aneurysms were measured at exactly 5 cm. This suggests that approximately 10% of all aneurysms that rupture in this series do so at 5 cm or less. Conclusion: In view of the safety of elective repair as compared with the prohibitive risk associated with aneurysm rupture, patients who are at good risk with small AAA (between 4 and 5 cm) should be considered for elective aneurysm resection. For unclear reasons, obstructive lung disease and diabetes are associated with a significantly greater risk for rupture of small AAA. Patients with these risk factors should be given special consideration. (J Vasc Surg 1998;28:884-8.)Journal of Vascular Surgery 12/1998; · 2.88 Impact Factor