Background: Circular stapling is the most commonly used anastomosis method after esophagectomy. However, it is unclear to what extent the diameter of the stapler affects the occurrence of postoperative anastomotic leakage, given the elasticity of gastrointestinal tissues that can adapt to a range of stapler sizes. This study aimed to observe and evaluate the possible effects of various diameters of circular staplers on anastomotic efficacy in gastroesophageal anastomoses of the same diameter.

Methods: Four circular staplers with different diameters from the same series were used to investigate the anastomotic effect on eight groups of fresh porcine esophagogastric tissues, with 32 anastomoses being tested. Anastomotic seepage was inspected using normal saline diluted with methylene blue.

Results: No stapling failure was observed in any of the 32 anastomoses; however, two anastomoses in the 21 mm stapler group showed deviation in staple line approximation and mild fluid leakage. This issue was corrected by intensive tissue trimming at the root of the stapler's base.

Conclusion: A smaller circular stapler may cause poor anastomotic alignment and seepage of the digestive juices due to the thicker esophageal tissue remaining at the base of the stapler. It is recommended that the internal diameter of the esophagus be tested in clinical practice using a valve-size tester, similar to that used in valve surgery, to select a larger circular stapler whenever possible.