Type B aortic dissection in Marfan patients after the David procedure: Insights from patient-specific simulation

Objective

An elevated risk of acute type B aortic dissection exists in patients with Marfan syndrome after the David procedure. This study explores hemodynamic changes in the descending aorta postsurgery.

Methods

A single-center retrospective review identified 5 patients with Marfan syndrome who experienced acute type B aortic dissection within 6 years after the David procedure, alongside 5 matched patients with Marfan syndrome without dissection more than 6 years postsurgery. Baseline and postoperative computed tomography and magnetic resonance scans were analyzed for aortic geometry reconstruction. Computational fluid dynamic simulations evaluated preoperative and postoperative hemodynamics.

Results

Patients with acute type B aortic dissection showed lower blood flow velocities, increased vortices, and altered velocity profiles in the proximal descending aorta compared with controls. Preoperatively, median time-averaged wall shear stress in the descending aorta was lower in patients with acute type B aortic dissection (control: 1.76 [1.50-2.83] Pa, dissection: 1.16 [1.06-1.30] Pa, P = .047). Postsurgery, neither group had significant time-averaged wall shear stress changes (dissection: P = .69, control: P = .53). Localized analysis revealed surgery-induced time-averaged wall shear stress increases near the subclavian artery in the dissection group (range, +0.30 to +1.05 Pa, each comparison, P < .05). No such changes were observed in controls. Oscillatory shear index and relative residence time were higher in patients with acute type B aortic dissection before and after surgery versus controls.

Conclusions

Hemodynamics likely play a role in post–David procedure acute type B aortic dissection. Further investigation into aortic geometry, hemodynamics, and postoperative acute type B aortic dissection is vital for enhancing outcomes and refining surgical strategies in patients with Marfan syndrome.