Endocutter Staple Height Auto-Adjusts to Tissue Thickness

Abstract

Surgeon choice of the appropriate staple height has been cited as a factor in the mechanical integrity of a staple line. However, tissue measured at the industry standard 8 g/mm2 is usually thicker than the formed staple height of the staples that hold it together. This means that the pressure that the staples apply must be greater than 8g/mm2. Additionally, formed staple heights in tissue may be different than formed staple heights of the same cartridge type when fired without tissue. This means that there is likely a compressive limit to the individual staples deployed by the stapling system. The purpose of this study is to establish the degree to which staple heights of endocutter staples auto-adjust to tissue and the compressive limit to tissue that this infers. Excised gastric remnants from laparoscopic sleeve gastrectomy were measured for tissue thickness at different external pressures. An optimized experimental staple line was then created in parallel to the clinical staple line. The doubly-stapled gastric sliver then underwent computed tomography with solid modeling software to measure staple heights. Staple heights fired in gastric tissue were significantly different than industry labelled and control staple heights. Clinical staple heights were significantly shorter than measured tissue thickness at 8 g/mm2. Staple height more closely approximated tissue thickness under 15 g/mm2 of pressure, rather than the 8 g/mm2 loading pressure used by industry for tissue thickness range labelling. Staples deployed in human gastric tissue are taller than commercial labelling. The closed staple height corresponds to tissue thickness under 15g/mm2 of pressure, not the labelled staple height. These results demonstrate that staple heights from modern endocutter staplers adjust to tissue, approximating a maximum compressive force just above 15g/mm2.