Examination of factors in type I endoleak development after thoracic endovascular repair

Objective: The objective of this study was to assess the effects of operative indication, anatomy, and stent graft on type I endoleak occurrence after thoracic endovascular aortic repair. Methods: A retrospective review was conducted of patients admitted for thoracic endovascular aortic repair between 2007 and 2013. All computed tomography angiography imaging was analyzed for the presence of endoleak and measurement of diameters and lengths. Variables studied included underlying disease, emergency, achieved aortic neck length, difference between proximal and distal neck diameters, landing zone 2, and stent graft characteristics (diameter, number, type of device, oversizing degree, and covered aorta length). Results: The study population involved 84 patients (mean age, 56 years; range, 17-94 years) who were treated for thoracic aortic aneurysm (TAA) (n = 29; 34.5%), traumatic aortic rupture (n = 27; 32%), type B aortic dissection (n = 19; 22.5%), intramural hematoma (n = 2; 2%), penetrating aortic ulcer (n = 5; 6%), and aortoesophageal fistula (n = 2; 2%). Of these, 60 patients (71.5%) were treated emergently and 24 (28.5%) electively. Primary type I endoleak was noted in eight patients (9.5%), of which two resolved spontaneously. After a mean follow-up of 32 months (range, 3-76 months), secondary type I endoleak was detected in four patients (4.5%). All of them occurred after emergent TAA treatment. Comparison between emergent and elective groups revealed no significant differences in neck length (19.5 mm vs 26.5 mm; P = .197), oversizing degree (11.1% vs 10.9%; P = .811), or endoleak rates (13.3% vs 8.3%; P = .518). Hemorrhagic shock was not predictive of endoleak (P = .483). Cox regression analysis of the different anatomic and stent graft-related factors revealed short proximal landing zone as the unique independent predictor of type I endoleak (hazard ratio, 0.89; 95% confidence interval, 0.81-0.99; P = .032). Conclusions: Endoleak risk seems not to be increased by an emergency setting. However, the relatively high rate of late endoleak observed after emergent TAA repair advocates for close follow-up, contrary to traumatic aortic rupture. Furthermore, regardless of the pathologic process, a longer proximal landing zone is likely to guarantee early and late success.