Risk Factor Analysis for the Mal-Positioning of Thoracic Aortic Stent Grafts.
The present study aimed at quantifying mal-positioning during thoracic endovascular aortic repair and analysing the extent to which anatomical factors influence the exact stent graft positioning.



A retrospective review was conducted of patients treated between 2007 and 2014 with a stent graft for whom proximal landing zones (LZ) could be precisely located by anatomical fixed landmarks, that is LZ 1, 2, or 3. The study included 66 patients (54 men; mean age 51 years, range 17-83 years) treated for traumatic aortic rupture (n = 27), type B aortic dissection (n = 21), thoracic aortic aneurysm (n = 8), penetrating aortic ulcer (n = 5), intramural hematoma (n = 1), and floating aortic thrombus (n = 4). Pharmacologic hemodynamic control was systematically obtained during stent graft deployment. Pre- and post-operative computed tomographic angiography was reviewed to quantify the distance between planned and achieved LZ and to analyze different anatomical factors: iliac diameter, calcification degree, aortic angulation at the proximal deployment zone, and tortuosity index (TI).



Primary endoleak was noted in seven cases (10%): five type I (7%) and two type II (3%). Over a mean 35 month follow up (range 3-95 months), secondary endoleak was detected in two patients (3%), both type I, and stent graft migration was seen in three patients. Mal-positioning varied from 2 to 15 mm. A cutoff value of 11 mm was identified as an adverse event risk. Univariate analysis showed that TI and LZ were significantly associated with mal-positioning (p = .01, p = .04 respectively), and that aortic angulation tends to reach significance (p = .08). No influence of deployment mechanism (p = .50) or stent graft generation (p = .71) or access-related factors was observed. Multivariate analysis identified TI as the unique independent risk factor of mal-positioning (OR 241, 95% CI 1-6,149, p = .05). A TI >1.68 was optimal for inaccurate deployment prediction.



TI calculation can be useful to anticipate difficulties during stent graft deployment and to reduce mal-positioning.
Aix-Marseille Université, IFSTTAR, Marseille, France; APHM, University Hospital Nord, Department of Vascular Surgery, Marseille, France; Aix-Marseille Université, CNRS, Ecole Centrale Marseille, Marseille, France. Electronic address: mourad.boufi@ap-hm.fr.
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Boufi
Aix-Marseille Université, CNRS, Ecole Centrale Marseille, Marseille, France.
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Guivier-Curien
APHM, University Hospital Nord, Department of Vascular Surgery, Marseille, France.
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Dona
Aix-Marseille Université, Department of Public Health, Marseille, France.
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Loundou
Aix-Marseille Université, CNRS, Ecole Centrale Marseille, Marseille, France.
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Deplano
Aix-Marseille Université, CNRS, Ecole Centrale Marseille, Marseille, France.
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Boiron
APHM, University Hospital Nord, Department of Vascular Surgery, Marseille, France.
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Hartung
Aix-Marseille Université, IFSTTAR, Marseille, France; APHM, University Hospital Nord, Department of Vascular Surgery, Marseille, France.
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YS
Alimi
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D000072226:Computed Tomography Angiography; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*; D055815:Young Adult
Anatomy; Mal-positioning; Stent graft; Thoracic aorta