Trends in Surgical Case Volume During Pacific Partnership Missions Onboard USNS Mercy

Abstract

Introduction: Since 2006, the U.S. Navy has conducted six Pacific Partnership (PP) missions throughout Southeast Asia on board the U.S. Naval Ship Mercy (T-AH 19). This study describes trends in overall and surgical specialty operative volumes to better understand the burden of surgical disease treated during these humanitarian and civic assistance (HCA) operations. This information can assist medical planners and surgical leaders involved in future humanitarian missions.

Materials and methods: Following approval from the Naval Medical Center San Diego Institutional Review Board, a retrospective review of surgical case data was performed for the six PP missions from 2006 to 2018. Data collected included patient demographics, Current Procedural Terminology codes, and surgical specialty. The primary outcome was surgical case volume per specialty. Secondary outcomes included surgical staffing per mission and overall trends in operative volume.

Results: A total of 3,826 operative procedures were performed during the study period. Mission years in which case volume for both general surgery and ophthalmology were below their respective medians were associated with the least total surgical services to host nations (HNs). The number of active duty Navy surgeons varied with each mission; however, the staffing for a PP mission generally included at least two general surgeons, one ophthalmologist, one plastic surgeon, one pediatric surgeon, one orthopedic surgeon, one otolaryngologist, one oral surgeon, one urologist, and one obstetrician-gynecologist. Case volume per surgeon was highest in 2006 (50 cases per surgeon) and decreased after 2006, reaching an all-time low during the 2018 PP mission (10 cases per surgeon). Pediatric surgery and plastic surgery had the highest average case volumes per surgeon at 58 and 46 cases per surgeon, respectively, while oromaxillofacial surgery and neurosurgery had the lowest average case volumes per surgeon at 9 and 14 cases per surgeon, respectively.

Conclusions: Operative volume on military HCA missions is greatly influenced by the priorities of the HN, the mission focus, the number of individuals from the HN that present for screening, and the availability of personnel and resources available on the hospital ship. Future mission planning should optimize general surgery and ophthalmology staffing and essential equipment, as total mission case volumes were highly dependent upon the productivity of these two specialties. Careful determination of the surgical needs of HNs should serve as a guide for the selection of subspecialists to maximize effectiveness in future military HCA missions.