An Automatic Suturing Machine for Intestinal Anastomosis: Advantages Compared With Hand-Suturing Technique

One of the main procedures in intestinal surgery is anastomosis, which is mostly performed by stapling or hand suturing. Due to limitations of these methods, a novel automatic suturing machine was designed and fabricated in this study, equipped with a needle-driving system; a thread control mechanism, and a linear mechanism, which is applicable in intestinal anastomosis by making continuous sutures. The main advantages of the fabricated machine are employing biocompatible suture, from the tissue's adaptation point of view, and making a uniform suturing pattern, independent of surgeon's skill, and thus offering a greater strength than the hand-sutured specimen. In order to evaluate the capability of the fabricated machine and investigate the validity of the hypothesis made in this study, that is, a more uniform suture will result in a greater mechanical strength of the sutured tissue, in vitro tests were performed on human intestine specimens, which were manually sutured by an expert surgeon and by the automatic suturing machine. The tensile tests with an elongation rate of 5 mm/min were done for 90 specimens, in 9 groups with various suturing configurations. The optimum pattern, from the mechanical strength point of view, was found to be the same in both manual and automatic suturing methods, that is, h7 d6 ( h = distance of suture from the edge of the tissue = 7 mm, and d = distance between stitches = 6 mm). It was also shown that the maximum breaking strength, for the best suturing pattern, h7 d6, is significantly greater when the automatic suturing machine was employed, compared with the hand-sutured tissue ( P < .001).