The most often quoted landmark paper regarding aneurysm rupture is:

Law MR, Morris J, Wald NJ. Screening for abdominal aortic aneurysms. J Med Screening 1994; 1:110–15.71

Annual AAA rupture risk in relation to size is usually quoted as follows:

AAA size (cm)

Risk of rupture per year (%)

I accept. Repair 4.0 to 5.5 cm abdominal aneurysms should be done in patients with abdominal pain without digestive cause diagnosed or acute increasing size of 0.5 cm in 6months even smaller than 5 cm aneurysm and of course rupture.

But I agree there`s no evidence to justify elective intervention in patients with aneurisms < 5,0/5,5 cm. Although smaller aneurisms could be offered repair when the patients are healthy, there is no data to justify elective repair of small aneurisms.

There are not standard approach. The mortality/morbidity after treatment of AAA in a specific institution should not exceed the risk of the fatal rupture.

I Agree but The UK Small aneurism Trial(Lancet 1998) showed that early elective surgery did not offer any all-cause survival advantage over regular ultrasound surveillance. The ADAM TRIAL (N Eng J Med 2002) published similar findings. The Eurostar(JVS 2004) registry indicate that even with the single outcome of freedom from aneurysm-related death following EVAR deployment,the rate of AAAs measuring between 4,0 and 5,4 cm is 3% within 5 years. Clearly ,there is very weak evidence to justify either open surgery or endovascular intervention in patients with aneurysms measuring less than 5,0 cm.

I support Andrew Choomg answer

Systematic Review and Meta-Analysis of Growth Rates of Small Abdominal Aortic Aneurysms

Comment

This study provides evidence growth rates of AAAs increase with aneurysm diameter. However, it did not completely satisfy the primary goal to determine optimal surveillance intervals because of the marked heterogeneity of growth rates in individual studies. Whereas the data would indicate that larger aneurysms grow faster than smaller aneurysms, something most of us already suspected, it does not provide useful information on the influence of patient characteristics, including age, sex smoking, diabetes and other relevant factors on AAA growth rates that would help optimize recommendations for surveillance intervals.

Conclusion

In studies reporting growth rates of small abdominal aortic aneurysms (AAA) there is considerable variation in growth rate, beyond that which can be explained by aneurysm diameter alone.

References

1JT Powell, MJ Sweeting, LC Brown, et al.: Systematic Review and Meta-Analysis of Growth Rates of Small Abdominal Aortic Aneurysms. Br J Surg. 98 :609-618 2011 21412998

2GL Moneta: Systematic Review and Meta-Analysis of Growth Rates of Small Abdominal Aortic Aneurysms. J Vasc Surg. 54 (6):1847 2011

Other morbidity data frequently are missing or underestimated when discussing about intervention on small diameter AAAs. Endovascular approach determines femoral access that would be necessary in a a long term follow-up when new reinterventions would be necessary.

How predict growth rates in abdominal aortic aneurysm?

JAMA, February 27, 2013—Vol 309, No. 8

Surveillance Intervals for Small Abdominal Aortic Aneurysms

A Meta-analysis

Importance Small abdominal aortic aneurysms (AAAs [3.0cm-5.4cm in diameter]) are monitored by ultrasound surveillance. The intervals between surveillance scans should be chosen to detect an expanding aneurysm prior to rupture.

Results AAA growth and rupture rates varied considerably across studies.Foreach0.5-cm increase in AAA diameter, growth rates increased on average by 0.59 mm per year (95% CI, 0.51-0.66) and rupture rates increased by a factor of 1.91 (95% CI, 1.61-2.25). For example, to control the AAA growth risk in men of exceeding 5.5 cm to below 10%, on average, a 7.4-year surveillance interval (95% CI, 6.7-8.1) is sufficient for a 3.0-cm AAA, while an 8-month interval (95% CI, 7-10) is necessary for a 5.0-cm AAA. To control the risk of rupture in men to below 1%, the corresponding estimated surveillance intervals are 8.5 years (95% CI, 7.0-10.5) and 17 months (95% CI, 14-22).

Conclusion and Relevance In contrast to the commonly adopted surveillance intervals in current AAA screening programs, surveillance intervals of several years may be clinically acceptable for the majority of patients with small AAA.

In conclusion, they demonstrated that most of the smallest AAAs remains quiescent over many years. Their findings suggest that surveillance strategies for small AAAs could be refined to reduce the number and frequency of surveillance scans required.

*Authors/RESCAN Collaborators and Author Affiliations are listed at the end of this article. Corresponding Author: Simon G. Thompson, DSc, Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, England ([email protected] .uk).

HEALTH TECHNOLOGY ASSESSMENT

VOLUME 17 ISSUE 41 SEPTEMBER 2013 ISSN 1366-5278

Systematic review and meta-analysis of the growth and rupture rates of small abdominal aortic aneurysms: implications for surveillance intervals and their cost-effectiveness

SG Thompson, LC Brown, MJ Sweeting, MJ Bown, LG Kim, MJ Glover, MJ Buxton, JT Powell and the RESCAN collaborators

We don`t operate on small(3-5,4 cm) aneurysms,no matter how good the patient`s clinical condition could be.We entirely support the statements made by Dr. Ocke Reis.

Age , Gender, Rate of expansion, symptomaticity, etiology,comorbidities , benefit of medical treatment of aneurysm, consent with provided evidence can help to reach conclusion for a single patient. However more research can be done to provide evidence based decision in this era of endovascular surgery to assess/decrease rupture rate for small aneurysms versus facilities for follow up, cost effectiveness, benefit to society overall before making any generalized statement for all to follow.

Dear Ghulam Farid,

Thanks for your answer . I also agree with you!

We performed a study to predict aortic intervention in patients with distal aortic dissection and we found that distal aortic diameter 4cm or more at presentation predicts intervention in type B dissection. So we would recommend intervention at 4cm dissecting aneurysm.

Dear Amr Arafat,

Can you send your data about this topic ?

The indication to treatment of AAA by EVAR or opensurgery should not be based on diameter alone. Into the decision fall important several aspects: age and operative risk of the patient, comorbidities as malignant disease or planned surgery for other entities, shape of the aneurysm , and gender. We could show recently by biomechanical stree testing that in female patients the aortic wall is less stable and my rupture earlier than in men with the same AAA diameter (Gender differences in biomechanical properties, thrombus age, mass fraction and clinical factors of abdominal aortic aneurysms. Tong J, Schriefl AJ, Cohnert T, Holzapfel GA. Eur J Vasc Endovasc Surg. 2013 Apr;45(4):364-72. ) available on my research gate page. In summary we do treat women starting at 4.5 cm by either open or endovascular surgery, and we treated patients with excentric or symptomatic aneurysms starting at diameters of 4 cm, in symptomatic patients maybe even less.

Dear Tina U Cohnert,

Thanks for you contribution. 

Congratulations for your nice work!!!

You are quite right when you say that The indication to treatment of AAA by EVAR or opensurgery should not be based on diameter alone and your work bring to us amazing informations to offer better treatment to our patients.