Hybrid aortic procedures for endoluminal arch replacement in thoracic aneurysms and type B dissections.

The aim of this study was to report our clinical experience with and review current literature on endoluminal aortic hybrid techniques and to evaluate outcome in high-risk patients treated for complex aortic arch lesions combining conventional supra-aortic debranching bypasses with subsequent or staged thoracic endovascular grafting. Of 172 patients treated with thoracic endografts for different thoracic aortic pathologies within the last 8 years, the mid-aortic arch was involved in 25, i.e. at least the left common carotid artery had to be overstented and revascularized to provide a proper proximal landing zone. These debranching bypasses were performed as a simultaneous or a staged procedure. All patients were at high-risk and were excluded by cardiac surgeons as ineligible for conventional arch repair. After partial (n=16) or complete (n=9) supra-aortic transposition, 4 different commercially available endografts (80% TAG, WL Gore) were implanted transfemorally or via iliac conduit. Deployment success was 100% in 25 patients after simultaneous or staged supra-aortic transposition; in 32% an emergency procedure was performed due to contained rupture; in 36% more than 1 endograft system was implanted (2 in 20%, 3 in 8% und 4 in 8%). The overall perioperative thirty-day mortality was 5 of 25 (20%) due to interoperative proximal bare stent perforation (n=1), transfusion related acute lung injury (TRALI n=1), cardiac failure (n=1), embolic stroke (n=1) and pneumonia (n=1). The mean follow-up was 21 months. All endoleaks type I (n=3) were corrected with another endograft; the 2 endoleaks type II sealed spontaneously. The major adverse events were: prolonged ventilation in 5 (20%), temporary renal insufficiency with hemodialysis (n=2), bypass infection (n=1), without any complications (n=9). No cases of paraplegia were recorded. Hybrid aortic arch repair is technically challenging but feasible. This novel approach may be an alternative to standard open procedures in high-risk patients and emergency cases. However, the promising early results need to be confirmed by longer follow-up and larger series.

Intraindividual assessment of the thoracic aorta using contrast and non-contrast-enhanced MR angiography.

PURPOSE: To avoid intravenous contrast media application, new MRA sequences using inherent blood contrast are available. The clinical use of these non-contrast-enhanced MRA (non-CE-MRA) sequences is still limited for the aorta. Thus, the goal was to compare a standard CE-MRA with a non-CE-MRA for the thoracic aorta. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. CE-MRA and non-CE-MRA (1.5 T) were performed in the same 50 healthy volunteers (mean age: 48). CE-MRA: GRE-Turbo-Flash-3D (1.2 x 1.2 x 1.6 mm (3)), 0.15 mmol Gd/kg, TA 22 +/- 2 sec. Non-CE-MRA: Respiratory-and cardiac-gated, T 2-prepared 3D-trueFISP (1.2 x 1.2 x 1.3 mm (3)), TA 14 +/- 5 min. Assessment included (3 readers, consensus): image quality (sharpness of vessel wall, signal homogeneity, artifacts) at the ascending aorta, arch, descending aorta and supra-aortic vessels. RESULTS: The image quality in the ascending aorta was rated 'excellent' in 78 %, 'moderate' in 22 %, 'poor' in 0 % for non-CE-MRA versus 22 %, 50 %, and 28 % for CE-MRA (Cohen's kappa = 29 %, McNemar p < 0.001). In a comparison of non-CE-MRA versus CE-MRA, the aortic arch and descending aorta showed no significant difference (kappa = 58 %/p = 0.250 and kappa = 100 %/p = 1.000, respectively). Supra-aortic vessels were rated 'excellent' 45 %/ 49 %, 'moderate' 30 %/ 49 % and 'poor' 13 %/ 2 %, 12 % of supra-aortic vessels were visualized < 1 cm at non-CE-MRA. CONCLUSION: Diagnostic image quality of the thoracic aorta can be achieved without application of intravenous contrast media. Images of the aortic root using ECG-gated non-CE-MRA are superior to standard CE-MRA. This technique might be applicable in NSF patients.