De novo development of saccular aneurysms: report of two cases.

The development of de novo aneurysms after previous successfully treated aneurysms is uncommon. If risk factors are not present the patient may be reassured that the risk of developing a further aneurysm following successful treatment is minimal. Two cases of second aneurysms developing six and eighteen years after successful treatment of a first aneurysm are reported. The risk factors associated with the formation of second aneurysms are emphasized.