Bilal M. Shafi

Profiling surgical staplers: effect of staple height, buttress, and overlap on staple line failure.

BACKGROUND Few studies have been designed to assess the performance of surgical staplers. In this study, we analyzed the effect of staple height, buttressing, and overlapping of staple lines on staple line failure. METHODS Staple lines created on fresh porcine small bowel segments ex vivo were tested for leak pressure by insufflating air into the bowel under water and recording pressure at failure. Three separate experiments were done and included staple height (white, 2.5 mm, n = 16; blue, 3.5 mm, n = 16; green, 4.1 mm, n = 16; one half of them buttressed); the absence (n = 12) or presence (n = 12) of an overlap in 3.5-mm staple lines; and the absence (n = 14) or presence (n = 11) of buttresses in 3.5-mm overlapping staple lines. Data are reported in median values and ranges; nonparametric tests were used for data analysis. RESULTS In the porcine small bowel, leak pressure was related to staple height; green loads had the worst profile (35 mm Hg, range 19-105) compared with the blue (79 mm Hg, range 9-177), and white (108 mm Hg, range 28-280) loads (P = .006). Buttressing uniformly improved leak pressure for all staple loads (P <.0001). No significant difference was found between lines with overlapping (59 mm Hg, range 32-121) and those without (42 mm Hg, range 22-75; P = .162). Buttressing also improved the leak pressure of overlapping staple lines from 65 mm Hg (range 47-121) to 93 mm Hg (range 75-187; P = .0014). CONCLUSION Great variability was found in the leak pressures among the different applications of the same stapler. Staple height is an important determinant of leak pressure. The presence of an overlap did not affect leak pressure; in fact, a trend toward improvement was seen with overlapping staple lines. Buttressing improved all types of staple lines.

Injectable Biomaterials in Surgery

Biomaterials in clinical practice encompass an enormous breadth of different materials, performing varied functions and taking different forms. Injected biomaterials are a unique subset within the biomaterial field, really entering the mainstream in recent years with the proliferation of minimally invasive technologies. Undoubtedly, as the breadth and depth of minimally invasive technology continues to grow, there will be a continued and even growing emphasis on newer materials or in some cases adaptation of older materials for novel applications.