The purpose of this national observational study is to evaluate the Thoraflex™ Hybrid vascular prosthesis in the replacement of the aortic arch and the treatment of aneurysm/dissection of the descending thoracic aorta in relation to morbidity-mortality, visceral malperfusions, neurological and renal complications, endoleak and evolution of the aortic thoracic stent over time.

Quality control will be performed continuously at various stages of the error correction process, according to the sponsor's Standard Operating Procedures.

Systematic coherence control procedures will be implemented and documented. The correction procedures will be tracked. For the study data, requests (Queries) will be issued and transmitted to the various centres for resolution.

To ensure data quality, a Monitoring Plan will be implemented. This plan will detail the frequency of visits or check-ups and the proportion of the data verified. It is expected that at least 10% of the data will be verified.

The monitoring factors in relation to the quality of electronic case report form completion will be performed by one of the Clinical Research Associates.

The participating physicians will be automatically contacted in the event of the absence of data entry after inclusion of patients and/or dates of scheduled visits and planned controls.

All of the analyses will be managed by the Direction de la Recherche Clinique et de l'Innovation of CHU Amiens. The statistical analysis software to be used is SAS (version 9.1). According to the target population, a sample of approximately 80 to 100 patients is anticipated, which would enable accuracy of ± 8.5 to 9.5% for an estimation of an event rate of around 25%.

During implementation of the study, the observers will be asked to minimise any missing data. The data collected is comparable to usual practice, which should be available from the original medical record. However, in the event of absence of the latter, the note missing data will be added to the data collection form. Several measures will be taken to avoid patients being lost to follow-up.

The study documents provided to the observers for initiation emphasise the fundamental importance of patient follow-up and the collection of data during the entire study. If necessary, scientific societies as well as the French National Authority of Health (HAS) may remind the observers of their obligation to actively participate in the existing national observational study.

The observer will obtain the means to contact the patient, his/her General Practitioner or close friend/next of kin.

Demographic and medical data of patients and follow-up descriptive data will be reflected in the patient population included.

Qualitative parameters are described by their frequency distribution and related bilateral 95% confidence intervals, quantitative parameters by their average, standard deviation minimum, maximum, median and quartiles, number of missing values.

Each of the rates corresponding to the study criteria is analysed by calculating the frequencies of distribution and related bilateral 95% confidence intervals (95% CI).

The rate of events over time will be described by a survival curve using the Kaplan Meier method and the related Kaplan Meier estimators will be calculated.

On an exploratory basis, the criteria in the study will also be analysed according to the basic characteristics of the patients:

• Age (in categories)
• Sex
• Indications.

Inclusion Criteria:

• Patient presenting an aneurysm/dissection of the thoracic aorta of the aortic arch and/or the descending thoracic aorta, and necessitating a procedure of the "Elephant Trunk" type, with the Thoraflex™ Hybrid hybrid vascular prosthesis.

Exclusion Criteria:

• Patient having refused to sign the Consent form to the use of his/her data.
• Patient residing abroad, for whom follow-up is not possible.
• Patient with active endocarditis
• Patient who has received a post-infarction septal repair.
• A list of all of the patients who have received the Thoraflex™ Hybrid hybrid vascular prosthesis but not participating in the observational study will be documented, as well as the reasons for non-inclusion

Any patient presenting an aneurysm/dissection of the thoracic aorta of the aortic arch and/or the descending thoracic aorta and necessitating surgery of the Elephant Trunk type. To meet the requirements of the French National Authority for Health, this study will include all the patients treated with the Thoraflex™ Hybrid hybrid vascular prosthesis. Any surgeon practising in France and wishing to inplant a Thoraflex™ Hybrid hybrid vascular prosthesis will be available from the coordinating observer.