Anatomical Feasibility of the “Canaud Technique” for Physician-Modified Thoracic Endovascular Grafts for the Treatment of Aortic Arch Disease

Abstract

Purpose:

Thoracic endovascular aortic repair (TEVAR), originally conceived for deployment distal to the left subclavian artery (LSA), has been recently extended to more proximal landing zones. Among total endovascular solutions, the “Canaud technique” for Physician-Modified Thoracic Endovascular Grafts (C-PMEGs) has gained acceptance with good early results. The aim of this study is to report the proportion of patients with zone 0, 1, and 2 aortic arch lesions that could theoretically be treated with a C-PMEG.

Materials and Methods:

Computed tomography angiography (CTA) of all consecutive patient candidates to open, hybrid, or endovascular arch repair from January 2009 to July 2023 at our Institution were analyzed. The assessment of feasibility of C-PEMG was conducted following previously extensively described anatomical criteria.

Results:

During the study period, 209 consecutive patients were candidates for an open, hybrid, or endovascular aortic arch repair. Of them, 164 patients had a preoperative CTA scan eligible for analysis. One hundred twenty-six patients were male (76.8 %), with a mean age of 67 ± 10.8 years. Ninety-four patients (57.3%) were affected by atherosclerotic aneurysms, 48 post-dissecting aneurysms (29.3%) and 22 penetrating aortic ulcers (PAUs) (13.4%). Twenty patients (12.2%) were suitable for double-fenestrated C-PMEG, and 34 patients (20.7%) for single-fenestrated C-PMEG, totaling 32.9% of the entire cohort. The combination of supra-aortic trunks (SAT) bypass or the use of covered stent in IA or left common carotid artery (LCCA) as adjunctive maneuvers, would extend the C-PMEGs feasibility to 69 patients (42.1%). The use of an iliac graft conduit in 3 (1.8%) patients with inadequate ileo-femoral accesses would increase the C-PMEG suitability to 72 patients (43.9%). The main reason for exclusion was excessive ascending aortic diameter in 78 patients (47.6%).

Conclusions:

The use of C-PMEG was shown to be theoretically feasible in a percentage of patients ranging from 32.9 to 43.9% affected by aortic arch aneurysms, dissections, and PAU. The main reason for exclusion was the dimension of the ascending aorta. The C-PMEG technique is a viable option in aortic arch lesions endovascular treatment. An off-the-shelf device with similar characteristics could also be used in emergency, avoiding the limitations of physician modifications (such as time for back-table procedure, sterility, off-label use).

Clinical Impact

Thoracic endovascular aortic repair (TEVAR) has been extended to more proximal landing zones for the treatment of aortic arch aneurysm, dissections, penetrating aortic ulcers. Among total endovascular solutions, the “Canaud technique” for Physician-Modified Thoracic Endovascular Grafts (C-PMEGs) has gained acceptance with good early results. The anatomical feasibility in 164 consecutive patients was 69 patients (42.1%), with the combination of supra-aortic trunks (SAT) bypass or the use of covered stent in IA or left common carotid artery (LCCA) as adjunctive maneuvers, showing that the C-PMEG technique is a viable option in aortic arch lesions endovascular treatment.