Endovascular Treatment for Pseudoaneurysms After the Surgical Repair of Aortic Coarctation

Impact of extra-anatomical bypass on coarctation fluid dynamics using patient-specific lumped parameter and Lattice Boltzmann modeling

Accurate hemodynamic analysis is not only crucial for successful diagnosis of coarctation of the aorta (COA), but intervention decisions also rely on the hemodynamics assessment in both pre and post intervention states to minimize patient risks. Despite ongoing advances in surgical techniques for COA treatments, the impacts of extra-anatomic bypass grafting, a surgical technique to treat COA, on the aorta are not always benign. Our objective was to investigate the impact of bypass grafting on aortic hemodynamics. We investigated the impact of bypass grafting on aortic hemodynamics using a patient-specific computational-mechanics framework in three patients with COA who underwent bypass grafting. Our results describe that bypass grafting improved some hemodynamic metrics while worsened the others: (1) Doppler pressure gradient improved (decreased) in all patients; (2) Bypass graft did not reduce the flow rate substantially through the COA; (3) Systemic arterial compliance increased in patients #1 and 3 and didn't change (improve) in patient 3; (4) Hypertension got worse in all patients; (5) The flow velocity magnitude improved (reduced) in patient 2 and 3 but did not improve significantly in patient 1; (6) There were elevated velocity magnitude, persistence of vortical flow structure, elevated turbulence characteristics, and elevated wall shear stress at the bypass graft junctions in all patients. We concluded that bypass graft may lead to pseudoaneurysm formation and potential aortic rupture as well as intimal hyperplasia due to the persistent abnormal and irregular aortic hemodynamics in some patients. Moreover, post-intervention, exposures of endothelial cells to high shear stress may lead to arterial remodeling, aneurysm, and rupture.

Late Complications After Previous Surgical Repair for Coarctation With Extra-Anatomic Bypass Graft: Report on Two Cases

Surgical correction of aortic coarctation (CoA) has been the standard treatment in infants and adolescents to prevent late consequences related to obstruction and distal hypoperfusion. Several surgical techniques for CoA repair have traditionally been applied. However, late complications, including re-CoA and pseudoaneurysm formation, are not uncommon. The incidence of complications is highly related to the type of initial surgery. Here, we are reporting two cases of late complications related to an infrequently used surgical technique, the extra-anatomical aortic bypass graft (EABG). The first case presented with pseudoaneurysm at the distal anastomosis site with the descending aorta and treated by endovascular stent graft. The second case presented with stenosis at the proximal anastomosis site with the left subclavian artery (LSCA) and treated medically upon the request of the patient.