Optimal Sizing of Aortic Stent Graft for Blunt Thoracic Aortic Injury Considering Hypotension-Related Decrease in Aortic Diameter

Purpose: To evaluate the optimal sizing of an aortic stent graft in patients with blunt thoracic aortic injury (BTAI), considering the decrease in diameter in hypovolemic status. Materials and Methods: From 2014 to 2020, 25 patients who underwent thoracic endovascular aortic repair (TEVAR) for BTAI were included. Hemodynamic parameters in the emergency room (ER) and just before the main procedure (MP) were collected. The aortic sizes were measured during initial computed tomography (CT) on arrival in the ER, aortography (AG) during TEVAR, and final CT in the outpatient clinic. The appropriateness of the inserted stent graft size was investigated. Results: The mean values of the final CT/initial CT and final CT/initial AG (proximal descending thoracic aorta [pDTA]) were 113% and 105%, respectively. The final CT/initial CT (pDTA; 122.2% vs 108.8%, p=0.01) and final CT/initial AG (pDTA; 113.4% vs 102.1%, p<0.01) were significantly higher in patients with systolic blood pressure (SBP; MP) ≤90 mm Hg. The final CT/initial CT (pDTA; 120.4% vs 109.0%, p=0.03) and final CT/initial AG (pDTA; 111.4% vs 102.6%, p=0.01) were significantly higher in patients with mean blood pressure (MBP; MP) ≤70 mm Hg. On an average, the inserted stent grafts were oversized by 130% on initial AG. Based on the final CT scan, the inserted stent graft was as large as 122%. Conclusion: In the case of hemodynamic instability with SBP (MP) ≤90 mm Hg or MBP (MP) ≤70 mm Hg, despite adequate resuscitation, an oversized TEVAR stent graft of 130% can reduce the occurrence of endoleak and is sufficiently safe. Clinical Impact Despite sufficient resuscitation, the aorta size measured during TEVAR in patients with hemodynamic instability with systolic BP <90 mmHg and mean BP <70 mmHg may be reduced by more than 15% compared to that in the normal state. In this study, the mean size of the stent grafts were oversized by 130% on initial aortography, but were oversized by 122% based on final CT. When the stent graft was oversized by 130% in TEVAR for hemodynamic unstable patient with BTAI, the patient reached the proper oversizing subsequent to hemodynamic recovery.