Purpose: To investigate the influence of
stent-graft oversizing on device-related complications after thoracic
endovascular aortic repair (TEVAR) for thoracic aortic aneurysm (TAA).
Methods: The study cohort was composed of patients
enrolled in 4 clinical trials of the TAG thoracic stent-graft. A total of 337
TAA patients (222 men; mean age 72 years) treated in these trials had sufficient
data for analysis of oversizing and post-procedure mortality and complications,
such as endoleak, migration, rupture, and reinterventions. Mean oversizing at
the proximal landing zone was 14.6% (range −3.4% to
39.7%). Patients were stratified based on the percentage of oversizing:
<10% (n=85, group 1), 10%–20%
(n=188, group 2), and >20% (n=64, group 3).
Results: Patients in group 1 had significantly
larger preoperative proximal aortic diameters (32.6 vs. 31.3 vs. 28.2 mm,
respectively; p<0.001) and neck lengths (6.9 vs. 5.8 vs. 5.2 cm
(p=0.035). Overall, type I endoleak was the most frequent complication
during the first 30 days of follow-up (35, 10.4%), but the incidences did
not differ among the 3 groups (10.6% vs. 11.2% vs. 7.8%,
respectively; p=0.809). Over a mean follow-up of 41.8±20.7 months,
there were no significant differences in the occurrence of device-related
complications among the groups, though the incidence of type I endoleaks was
lower in group 2 (9.4% vs. 3.2% vs. 7.8%, respectively;
p=0.073). Cox proportional hazards modeling showed no difference in the
time to type I endoleak among oversizing groups [group 1 vs. 2: HR 1.24,
95% CI 0.65 to 2.36 (p=0.509) and group 3 vs. 2: HR 1.24,
95% CI 0.60 to 2.60 (p=0.562)].
Conclusion: The percentage of oversizing did not
significantly affect the incidence of device-related complications after TEVAR
for TAA. Although oversizing may enhance the radial force and help maintain a
good proximal seal, additional oversizing seemed not to improve the overall
outcome in this analysis. The current guidelines regarding stent-graft
oversizing for TAA seem appropriate, though the correct percentage remains to be
determined
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