Operation Inherent Resolve Epidemiological Study of Surgical Cases Role III Combat Support Hospital, 2017-2021

Surgical workload in military operations evolves across phases of conflict, yet limited data describe operative volume and case mix during the transition to stability operations. Operation Inherent Resolve (OIR) provides a contemporary model to evaluate these changes at Role 3 facilities during Phase IV operations.

A retrospective review was conducted of operative encounters at a Role 3 military treatment facility during OIR (February 2017-October 2021). All cases performed in the operating room were included. Both battle injuries and disease and nonbattle injury (DNBI) cases were analyzed. Data collected included demographics, anatomic region, procedure performed, operative time, and surgical specialty involvement.

A total of 516 patients underwent 606 operative encounters. The mean age was 31 years, and 97% of patients were male. The largest proportion of patients were host-nation individuals (48%), followed by U.S. service members (34%) and coalition personnel (16%). Operative volume declined substantially over time, from more than 200 cases in 2017 to fewer than 50 in 2021. General surgery (39%) and orthopedic surgery (35.8%) accounted for most cases. Irrigation and debridement comprised 69% of orthopedic procedures. Notably, head and neck cases accounted for 26% of surgical sites, with otolaryngology representing a significant proportion of the operative workload. Noncombat surgical conditions, including appendicitis, remained stable despite declining overall case volume.

During Phase IV operations in OIR, operative volume declined while case diversity and subspecialty demands persisted. These findings support the need for a broadly capable Role 3 facility during stability operations. Strategies to maintain surgical readiness in low-volume environments are critical for future military medical planning.