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 only half of AAAs above 5 cm would have ruptured unoperated. Furthermore, conservative treatment of AAAs may cause psychological side effects and impaired quality of life. To optimise the indication and time for operation for AAAs, we analysed whether serum elastin peptides (EP), procollagen-IIIN-terminal propeptide (PIIINP), and the initial AAA size could predict operation for AAAs in initially conservatively treated AAA.


METHODS
in 1994, 4404 65-73 year old males were invited to hospital-based screening for AAAs by ultrasonography. Seventy-six percent attended. One hundred and forty-one (4.2%) had AAAs (def: +30 mm). Nineteen were offered operation (AAA +50 mm), and 112 were followed with annual control 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; 0.11-0.49), and NPIIIP ( 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 multivariate formula could by ROC curve analysis predict cases reaching 5 cm in 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 of these due to death or severe illness. Of these, seven would have been predicted to reach an AAA size recommendable for surgery. If all 23 were included in the analysis, the sensitivity and specificity would have been 87% and 85%, respectively.


CONCLUSIONS
a predictive model using EP, PIIINP, and initial AAA size seems capable of predicting nine out of 10 AAAs that will be operated on within 5 years. However, a larger sample size is needed for clinical recommendations.
Lindholt
J S
JS
Department of Vascular Surgery, Viborg Hospital, Viborg, Denmark.
Heickendorff
L
L
Vammen
S
S
Fasting
H
H
Henneberg
E W
EW
D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000097:blood* / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D015331:Cohort Studies; D003094:Collagen; D004549:Elastin / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016014:Linear Models; D008297:Male; D008403:Mass Screening; D010455:Peptides / Q000097:blood; D011237:Predictive Value of Tests; D011347:Procollagen / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D011863:Radioimmunoassay; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography
D010455:Peptides; D011347:Procollagen; D011498:Protein Precursors; C032431:preprocollagen; D003094:Collagen; D004549:Elastin