Impact of quantitatively determined native thoracic aortic tortuosity on endoleak development after thoracic...

The objective of our study was to assess whether there is an association between native thoracic aortic curvature and the development of endoleaks after thoracic endovascular aortic repair.

Quantitative analysis of the native aortic lumen was performed on preprocedural CT angiograms of 40 patients with thoracic aortic aneurysm treated by thoracic endovascular aortic repair. The curvature of the median centerline was measured. Tortuosity indexes were calculated on the basis of the sum of the curvature values within the diseased segment and in the proximal and distal fixation zones. The association between the tortuosity index and endoleak was analyzed.

Compared with patients without endoleaks, the tortuosity index of the proximal fixation zone was higher in patients with type Ia endoleak (9.5 vs 1.5 cm(-1), p < 0.01); the tortuosity index of the distal fixation zone was higher in type Ib endoleak patients (6.6 vs 0.5 cm(-1), p < 0.05); and the tortuosity indexes of the proximal fixation zone and of the diseased segment were higher in type III endoleak patients (11.0 vs 1.5 cm(-1), p < 0.01; and 15.8 vs 7.2 cm(-1), p < 0.01, respectively). Patients with a type III endoleak had longer diseased segments and larger mean diameters of the aneurysm than patients without endoleaks (148.6 vs 87.1 mm, p < 0.01; and 75.4 vs 63.2 mm, p < 0.05, respectively). Logistic regression analysis revealed that the risk of a type I or type III endoleak increased as the tortuosity index increased, with a 90% risk of endoleak at a tortuosity index of 10 cm(-1) in the proximal fixation zone.

Quantification of aortic tortuosity using CT angiograms may help to predict whether an endoleak will develop after thoracic endovascular aortic repair, and this quantification method may become an important tool for risk stratification before thoracic endovascular aortic repair.