Experimental evaluation of staple lines in gastric surgery

This study was designed to evaluate the bursting pressure, tensile strength, and healing of staple lines in the dog stomach. Pavlov pouches were created in 30 dogs using a single, double, or triple application of a stapler loaded with 4.8-mm staples. Staple lines were assessed immediately in half of the animals and after 21 days in the remaining animals. Acutely, reinforcing a single staple line with a second or third application of the stapler resulted in an anastomosis more resistant to leakage and disruption. Satisfactory healing occurred by 21 days and contributed to staple line strength in the pouches using a single and double application of the stapler. The orientation of collagen deposition in the anastomosis was related to the number of staples used. The degree of collagen deposition across the muscularis mucosa correlated with the healed staple line strength. Although healing occurred when a triple application of the stapler was utilized, the orientation of the fibroconnective tissue was parallel to the anastomosis and did not contribute to staple line integrity.