Ex vivo pneumostasis evaluation of a variable-height staple design.

OBJECTIVE: This study examined the effect of using a variable-height staple construct containing three rows of staples with heights of 3.0, 3.5, and 4.0 mm (staple leg length, medial to lateral) versus standard three-row single-height staplers (with staple heights of either 3.5 or 4.8 mm) for pneumostasis in healthy porcine and canine lung parenchyma to determine whether a single stapler that uses variable staple heights could perform as well as, or better than, existing single-height stapling devices. The work presented here used healthy animal tissues, in lieu of diseased tissue, which is extremely difficult to obtain and quantify. METHODS: Briefly, fresh explanted porcine and canine trachea-lung blocs were used for all testing. Tissue thicknesses were measured with a custom-design spring-loaded caliper before stapling with control and test articles to ensure that the tissue was of "appropriate" thickness for the stapler size (staple height) selected (per manufacturer's instructions for use). All tissue measurements were comparable across each area of lung tested, and both test and control devices were fired into the same tissue thicknesses. After stapling, the lungs were submerged in water, insufflated, checked for air leaks at four discrete (increasing) pressures, and scored using a predetermined scale. Statistical analysis was performed for n = 26 (3.5-mm staples), n = 29 (4.8-mm staples), and n = 26 or 29 (paired to the standard group) for the variable-height stapler (3.0-, 3.5-, and 4.0-mm staples). RESULTS: The results demonstrated that the test article comprising three rows of variable-height staples provided comparable pneumostasis with the standard three-row single-height staplers (with staple heights of either 3.5 or 4.8 mm) under the test conditions described. CONCLUSIONS: A novel test article containing three rows of staples with heights of 3.0, 3.5, and 4.0 mm (variable-height stapler) showed promising results when compared with standard commercially available single-height staplers, performing as well as or better than the standard single-height staplers. This work demonstrates important first steps to proving equivalent device performance, which might facilitate the use of a variable-height stapler in place of multiple single-height staplers.

Comparison of endostapler performance in challenging tissue applications.

BACKGROUND: Surgical staplers are frequently used in a variety of applications, demanding exacting instrument performance over a huge range of tissue compositions and disease states. The shape of a staple that is formed by a stapling device is one industry-accepted indicator of device performance; typically a B-shaped staple is considered the gold standard for staple formation. This B shape allows blood flow through the tissue, which is one important factor in the healing events that take place clinically after stapling. With the use of an animal model, this ex vivo study investigated staple formation when thick tissue endoscopic staplers were used on challenging and variable tissue. The setting was a corporate institution in the United States. METHODS: Two 60-mm linear endoscopic thick tissue reloads, a varied-height stapler (VHS), and a single-height stapler (SHS) were fired on 7 different regions of porcine stomach. Resultant staple formation was assessed per region of the stomach and evaluated for proper B-shaped staple formation and staple malformation. RESULTS: The VHS reload had significantly better B-shaped formation (P<.001) for all regions of the stomach and reduced occurrence of malformed staples in 5 of the 7 regions compared with the SHS reload, wherein the remaining 2 regions exhibited comparable malform occurrence. CONCLUSIONS: This study compared 2 thick tissue reloads and found that the VHS reload had superior outcomes, with respect to staple formation, compared with the SHS reload.