Stent Graft Oversizing is Associated with an Increased Risk of Long-Term Left Ventricular Wall Thickening in Young Patients Following Thoracic Endovascular Aortic Repair

The ventricular myocardium consists of a syncytium of myocytes organized into branching, transmurally oriented laminar sheets approximately four cells thick. When systolic deformation is expressed in an axis system determined by the anatomy of the laminar architecture, laminar sheets of myocytes shear and laterally extend in an approximately radial direction. These deformations account for ∼90% of normal systolic wall thickening in the left ventricular free wall. In the present study, we investigated whether the changes in systolic and diastolic function of the sheets were sensitive to alterations in systolic and diastolic load. Our results indicate that there is substantial reorientation of the laminar architecture during systole and diastole. Moreover, this reorientation is both site and load dependent. Thus as end-diastolic pressure is increased and the left ventricular wall thins, sheets shorten and rotate away from the radial direction due to transverse shearing, opposite of what occurs in systole. Both mechanisms of thickening contribute substantially to normal left ventricular wall function. Whereas the relative contributions of shear and extension are comparable at the base, sheet shear is the predominant factor at the apex. The magnitude of shortening/extension and shear increases with preload and decreases with afterload. These findings underscore the essential contribution of the laminar myocardial architecture for normal ventricular function throughout the cardiac cycle.

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Satisfactory Long-term Outcomes of Thoracic Endovascular Aortic Repair With a Bare Stent for Acute Complicated Type B Aortic Dissections

Journal of Endovascular Therapy ◽

10.1177/1526602820966991 ◽

2020 ◽

pp. 152660282096699

Author(s):

Yaowang Lin ◽

Shaohong Dong ◽

Jianfan Luo ◽

Weijie Bei ◽

Qiyun Liu ◽

...

Keyword(s):

Stent Graft ◽

False Lumen ◽

Thoracic Endovascular Aortic Repair ◽

Endovascular Aortic Repair ◽

Type B ◽

Stent Group ◽

True Lumen ◽

Aortic Remodeling

Purpose To compare the clinical outcomes after thoracic endovascular aortic repair (TEVAR) with a bare stent to those after TEVAR alone in patients with complicated acute type B aortic dissection (cATBAD). Materials and Methods A prospective, randomized trial was conducted at 2 medical centers in China between 2010 and 2013. Patients with cATBAD were randomly assigned to receive TEVAR with a bare stent (n=42) or TEVAR only (n=42). Patients were scheduled to undergo computed tomography angiography at 3, 6, and 12 months and then annually to 5 years. The primary endpoint was all-cause mortality at 5 years; secondary outcomes were a composite of complications (endoleak, stent-graft–induced new entry, aortic rupture, and secondary intervention) and aortic remodeling at 1 and 5 years. Results All-cause death occurred in 1 (2.4%) patient in the TEVAR with bare stent group (lung cancer) and 5 patients (11.9%) in the TEVAR group (4 aorta-related) during the 5-year follow-up (log-rank p=0.025). The 1- and 5-year rates of complications and secondary interventions did not differ between the groups. Patients in the TEVAR with bare stent group had higher increases in the thoracic true lumen diameter (19.7±3.6 vs 17.0±6.2 mm, p=0.018) and abdominal true lumen diameter (13.7±4.8 vs 7.2±6.1 mm, p<0.001) and a higher incidence of complete false lumen thrombosis (80.9% vs 47.6%, p=0.005) at the 1-year follow-up. However, no between-group differences in the changes of aortic remodeling parameters were observed between the 1- and 5-year follow-up periods. Conclusion The addition of a distal bare stent to a thoracic stent-graft during TEVAR was associated with significantly improved long-term survival in cATBAD patients vs TEVAR only, likely due to the prevention of true lumen collapse and improvement of complete false lumen thrombosis of the dissected aorta.

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