Profiling Surgical Staplers: Does Staple Direction Affect the Strength of the Anastomosis.

BACKGROUND: Few studies have been conducted regarding the optimal staple direction in gastrointestinal anastomosis. The purpose of this study was to evaluate the burst pressure of the anastomosis depending on the firing direction of the stapler.
METHODS: Pig esophagus and small bowel were used for all experiments. The small intestine represented a thin intestinal tract and the esophagus represented a thick intestinal tract. A side-to-side anastomosis was performed using a linear stapler, and the burst pressure was measured. A leak test on the anastomosis was then performed and burst pressures measured.
RESULTS: Burst pressures after anastomosis using a GIA™ 100-3.8 were 47.4 ± 10.4 mm Hg. With the same GIA, the burst pressure was significantly greater when the staples were driven from the small intestine into the esophagus (83.3 ± 17.3 mm Hg). Using the GIA™ 100-4.8, it was found that the burst pressure was significantly greater when the staplers were driven into the small intestine versus the esophagus (51.6 ± 7.1 vs. 68.6 ± 16.1 mm Hg). There was no significant difference between the different GIAs when fired in the same direction.
CONCLUSION: Burst pressures were significantly greater when the staplers were driven from the small intestine into the esophagus. The direction of the staple line influences the strength of the anastomosis.