Following the final definition of the proposed vein harvesting procedure, engineers defined the requirement for a 5-mm clip applier with specific features to enhance the procedure. Ethicon Endo-Surgery had previously released the AllPort 5 mm Clip Applier, which provided medium/large clips, to the market in March 1995.
According to a surgeon panel, however, the vein harvesting procedure would be greatly enhanced with a similar device, but with a longer shaft and smaller clip. As a result, the design team was split, with one group separately focusing on the new clip applier.
The AllPort or AllPort LS Clip Appliers are the first 5-mm clip appliers on the market. Previous endoscope clip appliers used 10-mm or larger shafts. "EES has designed and provided a revolutionary, self-adjusting clip that provides the tissue capacity of larger instruments, but within a 5-mm shaft," Michael Boehm, senior design engineer, explains. He adds that the new clip is " a unique configuration providing a spring-loaded, preformed titanium clip that automatically adjusts to the changes in tissue thickness. It provides ligation security through the least invasive type of instrument."
Key components of the AllPort device include jaws, low-glare shaft assembly, rotation knob, handle and trigger. The instrument delivers 20 or 30 clips, depending on the clip size.
It works like this. The surgeon partially squeezes the trigger to close the jaws of the instrument before inserting it into the body cavity. This action, the first stage of the firing sequence, closes the jaws, but does not advance a clip or fire the instrument.
Next, the surgeon positions the jaws so that they completely enclose the tissue to be ligated. The trigger is partially squeezed to close the jaws and verify tissue position. If the surgeon determines that positioning is not correct, the trigger can be released to open the jaws and reposition the tissue.
After ensuring that the tissue is properly positioned for ligation, the surgeon squeezes the trigger until it stops. A clip advances into the tissue, ligating the structure, and the trigger is released. The instrument is then ready to place another clip as required.