Rule of Four: A Value-Based Approach to Aortic Stent Graft Inventory Creation for the Treatment of Blunt Thoracic Aortic Injuries Using Real Patient Aortic Measurements

Abstract

As blunt thoracic aortic injury (BTAI) treatment has shifted from open to thoracic endovascular aortic repair, 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. Computed tomography scans of all patients with BTAI admitted to our level I trauma center from April 2010 to December 2018 were reviewed. Patients with anatomy incompatible with thoracic endovascular aortic repair 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 stent graft sizes by the manufacturer with the longest history of US Food and Drug Administration approval for BTAI. Stent graft sizes were then ranked based on the number of cases they would be suiTable for. Twenty-eight patients with BTAI were identified and three were excluded based on anatomic considerations. Most patients were male (68%), mean age 42.3 ± 20.2 years, mean Injury Severity Score 37.0 ± 9.8. Overall mortality was 25%. The Table summarizes the percentages of patients successfully treated by each combination of stent graft sizes. Of the 20 available stent graft options, a select combination of four stent grafts would successfully treat 96% of the patients in this study. Based on actual computed tomography scan aortic measurements, we demonstrated that an inventory of four sent-graft sizes was sufficient to successfully treat 96% of patients with BTAI. These data can be utilized as a value-based approach to aortic stent graft institutional inventory creation and maintenance.Table ICT scan measurements for graft ranking (left), percentage of patients with BTAI successfully treated with each stent-graft size and combination (right).VesselDiameter (mm ± SD)Aorta, at L carotid a. ostium23.4 ± 3.4Aorta, at L subclavian a. ostium22.2 ± 3.9Aorta, proximal to injury20.6 ± 4.3Aorta, distal to injury20.3 ± 4.5Common iliac a.9.1 ± 1.9External iliac a.7.4 ± 1.6Graft size combinations% Cases26, 26-21, 28, 31 mm9626, 26-21, 28 mm8426, 28, 31 mm8426, 28 mm7226 mm only5228 mm only4426 - 21 mm only3631 mm only28 Open table in a new tab