Stresses in aneurysm clips
Year: 1989
Type: article
Abstract: The hysteresis of prototype aneurysm clips made from either titanium alloy (Ti6Al4V) or Elgiloy (CoNi) have been compared. If aneurysm clips are opened too wide during insertion, stresses in excess of the yield strength of the material can be applied, causing hysteresis and uncertainty in the actual closing force. In this work, the authors demonstrated that, although mechanical test data on different alloys give useful guidance to the alloys' suitability of withstanding such loading, it is the design and geometric section of the device that determine the stress applied. Aneurysm clips formed from the two alloys were compared at maximum recommended extension using a Digital Force Gage to monitor the load applied, and yielding was demonstrated in certain aneurysm clip configurations. Consequently, it is clearly possible to overstress the clips, even using recommended procedures. Both the increase and decrease of the closing force of the clip after overstressing its spring are indicative of relaxation of residual stresses. This is unpredictable and therefore dangerous. It would be desirable for manufacturers to specify a value for the closing force of the clip after it has been opened to its maximum which could be used as a standard for surgeons. Regulatory agencies or neurosurgeons would therefore clearly benefit from improved standardization of calibration procedures for such clips.
Source: Clinical Materials
Authors: T. Reich, F. Schmidt
Institutions: NYU Langone Health, Rusk Rehabilitation, New York University
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W2058732149