Mastery of Operative Suturing/Stapling in Intestinal Surgery (MOSIS) Development of a Military General Surgery Resident Education Simulation Curriculum

Objective: To develop, implement, and evaluate the Mastery of Operative Suturing/Stapling in Intestinal Surgery (MOSIS) curriculum, a longitudinal, simulation-based educational program designed to enhance open intestinal surgery competency and military surgical readiness among general surgery residents. Design: Curriculum development and assessment study using the ADDIE instructional design framework. Validity was established through expert consensus among trauma and colorectal surgeons and supported through standardized evaluator training and checklist anchoring. Resident performance was measured using binary task checklists and structured technical assessment rubrics. Statistical analyses compared performance across postgraduate year (PGY) levels. Setting: A single tertiary academic military medical center. Participants: Thirty-three general surgery residents (PGY-1, n = 11; PGY-2, n = 4; PGY-3, n = 10, PGY-5, n = 8) enrolled in the MOSIS curriculum. Results: Performance on hand-sewn anastomoses demonstrated significant improvement with increasing training level. For single-layer end-to-end anastomosis, correct task completion increased from 78.6% (PGY-1) to 100% (PGY-5) (p = 0.002). For two-layer side-to-side anastomosis, performance improved from 83.3% (PGY-1) to 100% (PGY-5) (p = 0.001). In contrast, accuracy for stapled anastomoses was uniformly high across all PGY levels, with no statistically significant differences for side-to-side stapled (p = 0.255) or circular stapled configurations (p = 0.293). Conclusions: The MOSIS curriculum provides a structured, mastery-based framework that effectively develops open intestinal surgery skills among military general surgery residents. Significant PGY-related gains in hand-sewn anastomotic performance highlight the curriculum's educational impact. High stapled performance across levels suggests that targeted emphasis should remain on hand-sewn techniques essential for expeditionary and resource-limited environments. The MOSIS model is feasible, reproducible, and broadly applicable across military surgical training programs as a core component of military-unique curriculum and readiness preparation.