Four weaned male pigs (mean age, 4 卤 0 weeks; mean weight, 6.8 卤 0.1 kg) first underwent a 60-cm reversed intestinal segment followed by a STEP 4 to 6 weeks later. The LigaSure Impact (Covidien, Valleylab, Tyco Healthcare Group LP, Boulder, CO) was used to perform the procedure. Animals were fed on postoperative day 2 and terminated 1 week later. Morphometric data were collected, and intestinal tissue was obtained for histology.
Mean bowel caliber of 5.1 卤 0.5 cm was tapered to 1.8 卤 0.3 cm post-STEP with a mean increase in the length of the dilated segment of 82%卤 20%. All animals tolerated enteral feeding, and all survived to termination on day 7. Histologic evaluation revealed the zone of tissue fusion to be 7.1 卤 1.5 mm. Masson trichrome, hematoxylin and eosin, and polarized picrosirius red stains demonstrated that the fusion zone was well healed with overlying granulation tissue.
This is the first report of the successful application of radiofrequency energy to perform the STEP procedure in animals. Although further evaluation is required, tissue fusion devices may eventually provide an alternative to the linear stapler for the STEP procedure.