Rule of four: an anatomic and value-based approach to stent-graft inventory for blunt thoracic aortic injury.

Purpose: As blunt thoracic aortic injury (BTAI) treatment has shifted from open to thoracic endovascular aortic repair (TEVAR), logistical challenges exist in creating and maintaining inventories of appropriately sized stent-grafts, including storage demands, shelf-life management and cost. We hypothesized that most injured aortas can be successfully repaired with a narrow range of stent-graft sizes and present a value-based anatomic approach to optimizing inventory.

Methods: CT-scans of all patients with BTAI admitted to our Level I trauma center from Apr 2010-Dec 2018 were reviewed. Patients with anatomy incompatible with TEVAR were excluded. For each patient, after aortic sizing a set of two stent-grafts most likely to be utilized was selected from a list of twenty commercially available GORE conformable TAG endografts based on manufacturer instructions. Stent-graft sizes were then ranked based on the number of cases they would be suitable for. MATLAB was utilized to determine the combinations of stent-grafts which would cover the most patients.

Results: Twenty-eight patients with BTAI were identified and three were excluded based on iliac diameter. Most patients were male (68%), mean age 42.3 ± 20.2 years, mean ISS 37.0 ± 9.8. Overall mortality was 25%. Of the 20 available stent-graft options, a combination of four stent-grafts would successfully treat 100% of the patients in this series.

Conclusions: Based on actual CT-scan aortic measurements, we demonstrated that an inventory of four sent-graft sizes was sufficient to treat 100% of patients with BTAI. These data can be utilized as a value-based anatomic approach to aortic stent-graft institutional inventory creation and maintenance.