Evaluation of a commercial vascular clip: risk factors and predictors of failure from in vitro studies.

OBJECTIVE

To assess risk factors and predictors of failure of the Hem-o-lok(TM) vascular clip (Weck Closure Systems, Research Triangle Park, NC, USA) using vessels harvested from a porcine model.

MATERIALS AND METHODS

Vessels of various diameters were harvested from a porcine model, clipped at 90 degrees or 45 degrees using the Hem-o-lok clip and then cut either flush or with a 1-mm cuff. The vessels were then connected to a burst-pressure device and pressures required to burst the clip or to cause it to leak were measured.

RESULTS

The Hem-o-lok clip leaked or burst when the vessel to which it was applied was cut flush. The clip became even more likely to fail if the angle of application of the clip was not at 90 degrees to the vessel surface.

CONCLUSION

The Hem-o-lok vascular clip is safe if it is applied at 90 degrees to the vessel surface and, more importantly, if a 1-mm cuff is left between the clip and the point at which the vessel is divided. We would therefore discourage the practice of not leaving this cuff of tissue, in an attempt to maximize vessel length during laparoscopic donor nephrectomy.