Detachable parallel action clamp for endoscopic surgery

The existing occlusive clamps used in endoscopic surgery are modifications of the basic conventional scissors clamp design used in open surgery. All the current clamps, including atraumatic ones, cause tissue damage. The scissors design is intrinsically unsound because the occlusive force is not uniformly distributed and is much greater near the pivot end than between the free ends of the jaws. The ideal occlusive clamp should be based on parallel occluding jaws, as this mechanism ensures a uniform occlusion without undue crushing of the bowel. During the last two years we have been involved in the development of a detachable endoscopic atraumatic clamp. This has necessitated considerable biological experimentation, mechanical engineering design work, and clinical evaluation. The biological studies were concerned with the measurement of the forces (compression and friction) necessary to occlude and seal bowel at different intraluminal pressures without causing surface damage. The mechanical engineering and design development of the parallel jaw action clamp incorporating pseudoelastic nickel-titanium (Ni-Ti) spring was based on the data obtained from the biological studies. Once the basic design was established, miniaturization allowed the production and clinical evaluation of an endoscopic detachable parallel action clamp (DPAC) that can be introduced through 5.0-mm ports.