Corrosion of aneurysm clips: evaluation and clinical implications. Part II: Individual performance

The intracranial fracture of aneurysm clips due to stress corrosion failure is an increasingly common long term postoperative complication. To study the susceptibility of different clips to this process, we evaluated seven aneurysm clips (Mayfield, Yasargil, Vari-Angle McFadden, Scoville, Heifetz, and Pivot) in vitro. Microstructures, hardness, chemical composition, and susceptibility to stress corrosion failure were all measured by standard metallurgical techniques. Certain clips such as Heifetz, Pivot, and Vari-Angle showed a much greater propensity to stress corrosion failure than the others. As a result of our tests, we recommend that only the clips that show high stress corrosion resistance in in vitro testing should be considered for long term in vivo implantation.