DISCUSSION
In patients undergoing FET for chronic arch and/or descending aorta
aneurysms SCI has been reported in up to 20% of
cases4. Although CSFD has been a useful method to
relieve paraplegia after repair of type B acute aortic
dissection5, its role before, during and after surgery
for extended aortic aneurysms has not yet been clearly defined. Indeed,
there are still insufficient data to recommend the prophylactic use of
CSFD when FET is performed to treat patients with thoracic aortic
pathologies involving the aortic arch.
Katayama et al. reported postoperative SCI in 3.5% of patients
undergoing FET mostly for acute aortic dissection preoperative CSFD
being used in <10% of cases6; they
concluded that paraplegia may be prevented by avoiding deep insertion of
the stent graft and by maintaining an elevated blood pressure
postoperatively. According to a recent meta-analysis, FET was associated
to more adverse neurologic events in acute type A dissection while a
significantly lower risk of SCI was related to the use of a stent of 10
cm indicating that a stent 15 cm or greater or coverage extending up or
beyond T8 should be avoided7. On the other hand,
analyzing patients undergoing FET for acute aortic dissection others
found that the level of deployment of the distal edge of the stent graft
did not influence development of post-repair
paraplegia8.
In the present case pre-operative partial occlusion of intercostal
branches due to intra-aortic thrombotic stratification may have resulted
in chronic SCI. During surgery, temporary circulatory arrest and missed
antegrade perfusion of the left subclavian artery may have worsened
chronic SCI; nevertheless, during the procedure an evident subclavian
artery backflow indicated adequate flow in the left vertebral artery
while perfusion of the descending aorta was maintained with a catheter
inserted into the graft with adequate perfusion pressures. Furthermore,
post-operative CT scan showed a correct position of the short stent of
the Thoraflex graft, which was inserted under direct vision verifying
absence of intercostal branches in the covered thoracic aorta. The mild
ischemia due to the surgical procedure associated to pre-existing
chronic SCI may justify both the post-operative paraplegia and its rapid
reversal with CSFD.
The present case confirms that CSFD can effectively reverse paraplegia
after a FET procedure and that a successful outcome may be obtained by
early awakening the patient for accurate assessment of the neurological
status and timely detection of SCI. Furthermore, when using FET in
atherosclerotic aortic aneurysms with diffuse thrombotic wall
stratification it may be reasonable to consider the prophylactic use of
CSFD.