Does a small-diameter rod-type tunneler reduce postoperative swelling? An evaluation using a canine arteriovenous graft model.

PURPOSE: Sheath-type tunnelers are frequently used to create vascular access using vascular grafts. However, during vascular access creation, tunnelers damage the surrounding tissues, consequently causing problems, such as swelling, failure to heal, and infection. This study evaluated a novel rod-type tunneler that was designed to prevent tunneler-related tissue damage and its sequelae. METHODS: We developed a small-diameter rod-type tunneler that reduces injuries during subcutaneous tunnel creation. The rod diameter of this tunneler is smaller than the vascular graft diameter being implanted. It has a structure in which a vascular graft is implanted at a target site by grasping and pulling the vascular graft. Three dogs were used in the experiment, and arteriovenous grafts were created using a rod-type and a sheath-type tunneler on the left and right thighs, respectively, with a different type of commercially available graft used in each dog. The edema of the tissues surrounding the vascular graft was measured at 11 sites by ultrasonography at prespecified intervals. RESULTS: Compared with implantation using a sheath-type tunneler, when the self-sealing Rapidax II was implanted using the small-diameter rod-type tunneler, the postimplantation edema (degree of change) decreased by 28-53% and 80-247% in the peri-vascular-graft area and within the loop, respectively. The MAXIFLO and SEALPTFE did not significantly reduce postoperative edema but exhibited a tendency for improved postimplantation tissue healing. CONCLUSIONS: The reduced-diameter rod-type tunneler may be a useful device for vascular graft implantation.

Evaluation of a Spray-type, Novel Dextrin Hydrogel Adhesion Barrier Under Laparoscopic Conditions in a Porcine Uterine Horn Adhesion Model.

STUDY OBJECTIVE: To establish a porcine uterine horn adhesion model that mimicked laparoscopic procedures and use it to investigate the effect of a spray-type, novel dextrin hydrogel adhesion barrier (AdSpray; Terumo Corporation, Tokyo, Japan) on postsurgical adhesions. DESIGN: A single-blind randomized controlled trial (Canadian Task Force Classification I). SETTING: A Certified animal research facility. SUBJECTS: Sixteen female pigs. INTERVENTIONS: All animals underwent laparoscopically assisted adhesion-inducing surgery. The uterine horns and the peritoneum of the pelvic sidewall were injured. In the experimental group, AdSpray was applied to the injured site, and the handling of the sprayer was assessed. At 28 ± 1 days after surgery, animals were sacrificed, and adhesions at the injured site were evaluated. Uterine horn suture sites were examined under a light microscope to assess healing of the incised wound, the inflammatory reaction, abscess, and the foreign body reaction to the surgical suture. MEASUREMENTS AND MAIN RESULTS: The control group showed severe adhesions over the entire surface interface at the uterine horn suture sites and peritoneal resection site. Compared with the control treatment, AdSpray exhibited a higher percentage of adhesion-free sites (p < .001) and reduced the total adhesion score (p < .001). In the AdSpray group, no inflammation or abscess formation was observed on histopathological examination, and ideal healing of the suture sites was confirmed in all cases. CONCLUSION: Based on the results of the present study, the novel dextrin hydrogel shows excellent adhesion prevention and can be easily applied during laparoscopy using a dedicated sprayer.