Five-year results of elastin and collagen markers as predictive tools in the management of small abdominal aortic aneurysms

Objective: small abdominal aortic aneurysms (AAAs) do rupture and on;y half of AAAs above 5 cm would have ruptured unoperated. Furthermore, conservati ve treatment of AAAs may cause psychological side effects and impaired qual ity of life. To optimise the indication and time for operation for AAAs, we analysed whether serum elastin peptides (EP), procollagen-IIIN-terminal pr opeptide (PIIINP), and the initial AAA size could predict operation for AAA s in initially conservatively treated AAA. Material and Methods: in 1994, 4404 65-73 year old males were invited to ho spital-based screening for AAAs by ultrasonography. Seventy-six percent att ended. One hundred and forty-one (4.2%) had AAAs (def: +30 mm). Nineteen we re offered operation (AAA + 50 mm), and 112 were followed with annual contr ol scans for 1-5 years (mean 2.5 years). Of these, 99 had their EP (ng/ml) and PIIINP (ng/ml) determined using ELISA and RIA techniques. Two observers and one scanner were used. Results: the mean expansion rate was 2.7 mm/year. The initial AAA size (r = 0.46; 0.26-0.61), EP (r = 0.31; 0.11-0.19), and NIIIP (r = 0.24; 0.02-0.44 ) was independently significant associated to expansion rate in a multiple linear regression analysis including the three mentioned variables. The mul tivariate formula could by ROC curve analysis predict cases reaching 5 cm i n diameter within 5 years with a sensitivity and specificity of 91% and 87% , respectively, increasing to 91% and 94% respectively, by accepting a 2 mm variation in those measurements. Twenty-three were lost to follow up, 21 o f these due to death or severe illness. Of these, seven would have been pre dicted to reach an AAA size recommendable for surgery. If all 23 were inclu ded in the analysis, the specificity would have been 87% and 85%, respectiv ely.