Since the development of custom-made fenestrated and branched endografts a novel therapeutic option for the management of thoracoabdominal and para-renal aortic aneurysms was made accessible. Because of the design of these branched endografts, an arterial vascular access from the upper limb is required to allow selective catheterization of the branch component and the respective target vessel (celiac trunk, superior mesenteric artery, renal artery).2

Primary end-point is to evaluate the requirement of upper extremity arterial access (UEA) retrospectively in the cohort of patients with thoracoabdominal aortic aneurysms treated by means fenestrated and/or branched endografts in Vascular surgery San Raffaele Hospital between 2013 and 2017, and prospectively in the next 50 patients that will be treated between 2017 and 2020.

Secondary end-point is an anatomical evaluation of the different sites available for UEA(upper extremity arterial access ) based on pre-operative imaging studies.

Materials and methods:

The investigators review a prospectively compiled Microsoft Office Excel database with the procedural details of the 34 patients treated at Vascular surgery of San Raffaele Hospital between October 2013 and March 2017 by means of total endovascular thoracoabdominal aortic aneurysm repair and of those of the next 50 patients who will be treated until December 2020. All patients in which an UAE (upper extremity arterial access ) is employed will be identified together with the side (left/right) and site (proximal/distal axillary artery, brachial artery) of vascular access. Furthermore, the pre-operative contrast-enhanced computed tomography scans (CTA) of all patients, stored in the hospital PACS, will be analyzed on the dedicated workstation with OsiriX software (Pixmeo sarl, Bernex, Switzerland) currently employed at Vascular surgery of San Raffaele Hospital for imaging assessment.

Requirement of an UEA(upper extremity arterial access ) during the procedure is extrapolated from the corresponding field of the available database and reported together with side and site of access and reason for the employment of UEA (upper extremity arterial access ) and for its location.

Multi-planar, curved and 3D reconstructions of each patient CTA will be analyzed and the following measurements recorded:

1. patency of both potential upper extremity access vessels (right/left subclavian artery);
2. diameter of the proximal axillary artery on both sides;
3. diameter of the distal axillary artery on both sides;
4. presence of calcifications on the proximal axillary artery on both sides;
5. presence of calcifications on the distal axillary artery on both sides;
6. arterial tortuosity index on both sides: measured as the ratio between the axillary artery length measured on curved reconstruction and its length measured on 3D reconstruction.

All the assessed variables will be prospectively recorded in a Microsoft Office Excel database together with patients' weight, height, age and gender.

All patients involved in the retrospective part of the study have already signed informed consent for data collection and analysis at hospital admission.

The 50 patients that will be enrolled until December 2020 will also sign an "ad hoc" consents, specific for this study.

Sensitive patient information will not be available during data analysis. The clinical study will be carried out according to the ethical principles of the Declaration of Helsinki and following the active regulations on observational studies.

Analysis:

Patients characteristics and anatomical data on UEAs(upper extremity arterial access) will be analyzed on Wizard Statistics software to investigate the presence of statistically significant Pearson correlations among the identified variables.

The extracted data and their relevant clinical and procedural implications will be submitted for publication in peer-reviewed scientific journals focused on the field of vascular and endovascular surgery.

Inclusion criteria:

• Patient undergoing total endovascular treatment of thoracoabdominal pathology at San Raffaele Hospital in between October 2013 and December 2020.

Exclusion criteria:

• Incomplete imaging quality not including the arterial segments to be studied (axillary and brachial artery).

patient undergoing total endovascular treatment of thoracoabdominal pathology