The abnormal aorta: a statistical definition and strategy for monitoring change.

OBJECTIVES This study defines a protocol for monitoring the growth of small abdominal aortic aneurysms based on age-related abnormality thresholds, observed aortic growth patterns and the limits of precision of the measurement technique. DESIGN 13000 men aged 60 - 75 years were invited to their GP's surgery for measurement of the maximum diameter of the infrarenal aorta. Seventy-six percent responded and measurement was possible in 97.1% of the respondents. The AP diameter of the aorta was measured according to a strict protocol, with a portable ultrasound scanner. SETTING Cases were recruited from the conurbation of Birmingham and Solihull, U.K. CHIEF OUTCOME MEASURE: A statistical description of the differences in distributions of aortic diameters of four age groups of males. MAIN RESULT The aorta expands in diameter during the seventh and eighth decade for up to 25% of all those screened. The order of magnitude of this change is similar to that previously attributed to the growth of small aneurysms. Age-related thresholds for abnormality should range from 24 mm for a 60 year old to 37 mm for a 75 year old. CONCLUSIONS Using data on the expected maximum rate of change of the dilated aorta and statistically derived thresholds from this analysis a monitoring strategy is suggested for those with an abnormal aorta.

[1]  M. David Tilson,et al.  Suggested standards for reporting on arterial aneurysms , 1991 .

[2]  J. Collin,et al.  SCREENING FOR ABDOMINAL AORTIC ANEURYSMS , 1987, The Lancet.

[3]  J. Hamer,et al.  A statistical analysis of the growth of small abdominal aortic aneurysms. , 1994, European journal of vascular surgery.

[4]  N. Browse,et al.  Physiological studies in arteriomegaly. , 1974, Cardiovascular research.

[5]  R. Vogelzang,et al.  Normal aortoiliac diameters by CT. , 1988, Journal of computer assisted tomography.

[6]  M. P. Nevitt,et al.  Prognosis of abdominal aortic aneurysms. A population-based study. , 1989, The New England journal of medicine.

[7]  L. Holmberg,et al.  Natural history of patients with abdominal aortic aneurysm. , 1991, European journal of vascular surgery.

[8]  F. Fowkes,et al.  Increasing incidence of aortic aneurysms in England and Wales. , 1989, BMJ.

[9]  T. M. Silver,et al.  Actuarial analysis of variables associated with rupture of small abdominal aortic aneurysms. , 1985, Surgery.

[10]  B. Sonesson,et al.  Infrarenal aortic diameter in the healthy person. , 1994, European journal of vascular surgery.

[11]  D. Bergqvist,et al.  Natural history of abdominal aortic aneurysm detected by screening , 1993, The British journal of surgery.

[12]  F. Smith,et al.  Ultrasonographic screening for abdominal aortic aneurysm in an urban community , 1993, The British journal of surgery.

[13]  J. Powell,et al.  Limitations of ultrasonography in surveillance of small abdominal aortic aneurysms , 1991, The British journal of surgery.

[14]  O. Ekberg,et al.  A population based screening of abdominal aortic aneurysms (AAA). , 1991, European journal of vascular surgery.

[15]  J. Swedenborg,et al.  Ruptured abdominal aortic aneurysms: A study of incidence and mortality , 1986, The British journal of surgery.

[16]  P. Harris Reducing the mortality from abdominal aortic aneurysms: need for a national screening programme. , 1992, BMJ.

[17]  J. Collin ELECTIVE SURGERY FOR SMALL ABDOMINAL AORTIC ANEURYSMS , 1987, The Lancet.

[18]  B. Heather,et al.  General practice‐based population screening for abdominal aortic aneurysms: A pilot study , 1989, The British journal of surgery.

[19]  John W. Tukey,et al.  Exploratory Data Analysis. , 1979 .

[20]  D. Graham,et al.  Low density lipoprotein uptake by an endothelial-smooth muscle cell bilayer. , 1991, Journal of vascular surgery.

[21]  R. Limet,et al.  Determination of the expansion rate and incidence of rupture of abdominal aortic aneurysms. , 1991, Journal of vascular surgery.

[22]  H. Ashton,et al.  Abdominal aortic aneurysm in 4237 screened patients: Prevalence, development and management over 6 years , 1991, The British journal of surgery.

[23]  M. Docker,et al.  Accurate screening for abdominal aortic aneurysm. , 1992, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[24]  J. Collin,et al.  How fast do very small abdominal aortic aneurysms grow? , 1989, European journal of vascular surgery.