Determining ideal staple size for small intestinal surgery in cats

Background: The use of stapling equipment for intestinal surgery in cats is rarely reported, and appropriate staple sizes for cat intestine are unknown.
Objective: To determine staple cartridge sizes for thoracoabdominal (TA) and endoscopic gastrointestinal anastomosis (EndoGIA) that will simultaneously prevent leakage of small intestinal contents while also allowing for sufficient vascular permeability past the staple lines for intestinal healing. Methods: Two sizes of EndoGIA cartridges (2.0/2.5/3.0mm and 3.0/3.5/4.0mm) and two sizes of TA cartridges (2.5mm and 3.5mm), applied in a transverse manner across fresh cadaveric cat jejunum, were evaluated via intestinal burst pressure testing for maximum intraluminal pressure prior to leaking, and via infusion of an intravascular dye at normal arterial pressures to determine percentage of vascular patency past the staple lines. Vascular patency was compared not only from pre-and post-staple segments of the same intestinal sample, but also EndoGIA vascular patency was evaluated against TA vascular patency. Results: Two cats met study criteria. All samples had intraluminal burst pressures over twice the chosen minimum (of 30mmHg). Vascular patency post- staple line ranged from 0-90.8%, with the most consistently high numbers noted with the TA 3.5mm cartridges. No EndoGIA cartridge had a post- staple line vascular patency higher than 31.1%, and no intravascular dye was noted in any post- staple line sample in the EndoGIA 2.0/2.5/3.0mm group. Conclusions: While statistical analysis of the dataset was unable to be performed due to low numbers of samples for comparison, both intestinal intraluminal burst pressure trends and intravascular dye patterns suggested both the TA 3.5mm cartridge and (to a lesser extent) the 3.0/3.5/4.0mm EndoGIA cartridge could provide the ideal combination of intraluminal seal without restriction of vascular access for healing. The intravascular dye infusion technique, developed during this research, shows promise as a future instrument to determine vascular patterns around intestinal implants in cadaveric cat specimens.