Acute Aortic Disease.. - Index of

Endovascular Thoracic Aortic Stent Grafting 295
distal thoracoabdominal aorta approaching 92%. Panos and coworkers (99) reported
on five patients undergoing similar surgical strategy using the Endofit endoluminal
stent graft (Endomed Inc., Phoenix, Arizona, U.S.A.) with complete obliteration in
two patients and partial obliteration in three patients.
At the University of Pennsylvania, we have attempted to alter the prognosis
and natural history of the residual type B dissection following acute type A dissection
repair by stenting the distal aortic arch and descending thoracic aorta. We have
presented a method for simultaneous open repair of the aortic dissection and
antegrade “stented elephant trunk” stabilization of the descending aorta using thoracic
aortic stent grafts (Fig. 4) (101). To date, nine patients have been treated with
this technique, with five patients (56%) demonstrating complete thrombosis and
stabilization of the false lumen in the entire aorta (Fig. 5). Two patients (22%) had
stabilization of the descending thoracic aorta with persistence of the false lumen in
the aorta beginning at the level of the celiac axis. Two patients (22%) had persistent
false lumen in the descending thoracic aorta. Paraplegia did not develop in any of
the nine patients. Other reports of similar combined open and aortic stent graft repair
of acute type A dissection demonstrated comparable results of false lumen
obliteration and prevention of distal aortic aneursymal remodeling (96–99).
Arch Hybrids
Conventional repair of atherosclerotic aortic arch aneurysm is technically
demanding, requiring CPB and deep hypothermic circulatory arrest. Despite
recent improvements in surgical technique, total arch repairs of large atherosclerotic
arch aneurysms still have significant morbidity and mortality (102–105). In
contrast to nonatherosclerotic aortic arches, large atherosclerotic saccular aneurysms
of the arch are extremely high risk for perioperative stroke, as this disease
is a grave marker of extensive arch and brachiocephalic atheromatous disease. In
this subset of high risk patients, even the most recent series indicate in-hospital
mortality rates ranging from 6.3% to 20%, with stroke rates up to 12%
(43,106–111).
Beginning with descending thoracic aortic aneurysms, endovascular stent
graft technology has evolved as a safe and effective treatment for various thoracic
aortic diseases (20,46,50,112–115). Because of the anatomical features of the
aortic arch, endovascular therapy of arch aneurysms remains a technical challenge
(130,131). Maintaining cerebral perfusion and eliminating embolic events during
deployment are crucial for optimal neurologic outcome. Limited to Europe and
Japan due to the availability of stent graft devices, small series of combined extraanatomical
bypass of the great vessels with endovascular deployment of a stent
graft in the arch have been reported with promising results (102,116–121). With
FDA approval in 2005, the Gore TAG (W.L. Gore, Flagstaff, Arizona, U.S.A.)
thoracic endoprosthesis became available commercially in the United States.
Previously, these patients have been considered prohibitively high risk for
conventional open arch repair due to their comorbidities, including the atherosclerotic
burden in the arch and the associated high stroke risk.