gms | German Medical Science

Introduction: Endovascular treatment of the ascending aorta and the aortic arch is currently performed in selective patients. Multiple tortuous segments of the aorta may lead to inability to advance or deploy an endograft via conventional transfemoral access and may prohibit precise stentgraft placement. Aim of the experimental study was to test feasibility and hemodynamic alteration during antegrad-transcardiac instrumentation for endovasculat treatment of the ascending aorta in a porcine model. Conventional retrograde-transfemoral (TFA), was compared to to antegrade-transseptal access (TSA) and antegrade-transapical access (TAA) using through-and-through guidewire technique to the ascending aorta for endograft introduction.

Material and methods: Domestic pigs of either sex were investigated. TFA (n=6, 52±8 kgBW) was compared to TAA (n=6, 54±8 kgBW) and TSA (n=6 pigs, 54±6 kgBW). Custom-made endografts (polyester-tube + 2nitinol-stents, 24x32 mm) were advanced and deployed into the ascending aorta. Myocardial and cerebral perfusion were assessed by fluorescent-microspheres (FM). Hemodynamic parameters were evaluated during baseline (T1), sheath-forwarding (T2), endograft deployment (T3) and after retraction of the sheath (T4) by PiCCO and Swan-Ganz measurement. Transit-time flow measurement (TTFM) on the carotid artery was performed.

Results: Endograft deployment was feasible in all animals. All coronary arteries remained patent. Cardiac-output, heart rate and central-venous-pressure were stable throughout the whole study in all animals (p=n.s.). During T2 transient hemodynamic alteration due to transient severe valve insufficiency occurred during TSA and TAA while values remained stable during TFA, recovering during T4 within ten minutes in all animals. The innominate artery was partially occluded in 4 (TSA), 3 (TAA) and 5 (TFA) animals, reflected by reduced TTFM. There was no periprocedural deterioration of myocardial and cerebral perfusion assessed by FM. Endograft deployment during TAA lasted significantly shorter than in TSA and TFA.

Conclusion: Antegrade-transcardiac access to the ascending aorta is feasible in a porcine model. Transient hemodynamic instability in TSA and TAA recovered to near preoperative values. TAA caused less hemodynamic alteration. Transcardiac access might be a treatment option for selective patients unfit for open surgery to treat pathologies of the ascending aorta and the aortic arch.