4-Year Results of the Bolton Relay Proximal Scallop Endograft in the Management of Thoracic and Thoraco-Abdominal Aortic Pathology with Unfavourable Proximal Landing Zone.

ABSTRACT Introduction Thoracic endovascular aortic repair with a scallop design (scallop-TEVAR) is a useful treatment strategy to extend the proximal landing zone (PLZ), whilst maintaining perfusion to one or more of the supra-aortic trunks when treating aortic pathology with an unfavourable PLZ. The durability of this approach with the Bolton Relay scallop endograft (Terumo Aortic, Sunrise, Florida, United States) has not been established. Methods A retrospective review of prospectively collected data on consecutive patients that received scallop-TEVAR in zones 0-2 at a tertiary aortic unit was undertaken. The main outcome was durability, characterised by survival estimates, freedom from reintervention to the thoracic aorta and PLZ, migration and aneurysm sac regression. Results Between 2009-2019, 38 patients (71% male; median age of 70 years) underwent scallop-TEVAR for thoracic aortic pathology (n=28, 74%) or as part of thoracoabdominal aneurysm repair (n=10, 26%). The use of scallop-TEVAR significantly extended the PLZ (median 5mm preoperative PLZ vs 26mm extended PLZ, P=0.0001). A total of 41 supra-aortic trunks were perfused with a scallop including the LSA (n=25), LCCA (n=6), neo/IA (n=4), LSA and vertebral (n=1), IA and LCCA (n=2) in conjunction with 15 extra-anatomical bypasses. The PLZ was at Ishimaru zone 0 and 1 in 6 cases (16%), respectively, and zone 2 in 26 cases (68%). Technical success was 98%. The 30-day mortality was 5% (2/38; one death from myocardial infarction and one from multi-organ failure). Minor stroke occurred in three (8%) and temporary spinal cord ischaemia in two (5%) patients. Median follow-up was 4.5 years (0-10.53 years) during which two patients (5%) developed type Ia endoleak and required intervention to the PLZ (one from device-related migration and one from disease progression). All-cause and aorta-related survival was 72% and 85%; freedom from thoracic and PLZ reintervention was 92% and 97%, respectively. There were no cases of early or late thoracic aortic rupture, retrograde type A aortic dissection or supra-aortic trunk occlusion. Conclusions Scallop-TEVAR offers a less invasive treatment option to extend the seal zone in selected patients with an unfavourable PLZ, allowing for a durable repair in terms of overall survival and reintervention. Periprocedural stroke remains a principle concern.