What problems are anticipated during proximal graft deployment?

What problems are anticipated during proximal graft deployment?

Hemodynamic stability to preserve organ function is the primary goal for aortic endovascular stent placement. Various comorbid conditions make this particularly important. Special attention must be directed towards evaluating the function and reserves of cardiac, pul-monary, neurologic, and renal systems. Fluid requirements are potentially large because significant amounts of blood can be lost, often concealed, during these procedures. In addition, emergent conversion to open repair secondary to aortic rupture is always possible.

Distal migration of the endograft during proximal deployment may not include the aneurysm sac, causing endoleakage. Older endovascular stent-grafts employed large balloon angioplasty catheters to expand and secure the proximal stent attachment system of the endovascular graft to the underlying normal vessel wall. These balloons have a large cross-sectional area, predisposing them to dis-tal aortic migration as forward aortic blood flow pushes in downstream. Device malposition secondary to inadvertent migration may result in either occlusion of major arterial branches or incomplete aneurysm exclusion. Induced hypotension during device deployment has been success-fully used by some centers to assist in proximal endovascu-lar stent-graft placement and may reduce the magnitude of migration. However, significant endovascular stent-graft movement may nonetheless occur because of continued aortic blood flow. The risk of malposition may be decreased by induced hypotension using short-acting vasodilators, ventricular quiescence (achieved by either pharmacologic induction of sinoatrial and atrioventricular nodal inhibition with high-dose adenosine), or induced ventricular fibrillation. Most likely, no interventions are necessary for self-expanding devices placed in the infrarenal aorta.