[Is it necessary to operate on small abdominal aortic aneurysms?].

The indication for surgical treatment of aneurysms of 5 cm diameter or larger is no longer the subject of much debate but the problem still arises for aneurysms equal to or less than 4 cm in diameter. This problem is a real one since epidemiologic studies have shown the frequency of aortic aneurysms to be about 45/100,000 in men and 20/100,000 in women. The incidence of rupture in these small aneurysms is null for some authors, such as Névitt, for those of less than 5 cm, but Crawford reported an incidence of 9%. Exceptionally, rupture may occur in ectatic aortitis with weakened walls. Small aneurysms are generally kept under observation and not operated upon immediately. The increase in size varies between 21 and 40 mm according to the patient. Apart from the size of the aneurysm a further factor to be allowed for is the presence or absence of an intramural clot. In addition to the possible role it can play in the course of the aneurysm itself it may be the source of an emboli, which, after rupture, are the cause of the second symptomatology of aortic aneurysms. Indications for surgery of small aneurysms should be restricted to those with large intramural aneurysms, those with irregular morphology of a segment possibly the site of weakening of the wall which can be detected by a scan or NMR imaging, without forgetting certain sacciform aneurysms suggestive of a mycotic etiology and requiring surgery.(ABSTRACT TRUNCATED AT 250 WORDS)