Corrosion of aneurysm clips: evaluation and clinical implications. Part 1: Metallurgical foundations of stress corrosion failure.

Several intracranial failures of aneurysm clips have been documented recently. Consistently, the mechanism of failure has been stress corrosion. These failures could have been anticipated if certain metallurgical properties of the clips had been known. In this paper, we review the metallurgical basis of stress corrosion failure and offer serial metallurgical tests as screening procedures to determine a clip's propensity towards failure. The importance of determining a clip's fracture toughness, a key indicator of stress corrosion resistance, is emphasized.