Study Analyzes Appropriate Landing Zones for TEVAR in Acute Type B Aortic Dissections

January 24, 2022—The Society for Vascular Surgery (SVS) announced the publication of a study that evaluated the results of thoracic endovascular aortic repair (TEVAR) after acute type B aortic dissection (aTBAD). The findings suggest that most patients with aTBAD have < 2 cm of proximal healthy descending thoracic aorta.

The study was published by Tomaz Mesar, MD, et al in Journal of Vascular Surgery (JVS; 2022;75:38-46).

Jean Panneton, MD, the senior investigator of the study, commented in the SVS press release, “TEVAR for the treatment of complicated aTBAD has been shown to have favorable outcomes compared to both open aortic repair and medical therapy. However, the optimal approach for this therapy, including timing, coverage length, and landing zone remains to be fully elucidated.

“The aim of this study was to evaluate and compare postoperative outcomes and late aortic-related adverse events in patients undergoing TEVAR for complicated aTBAD with proximal endograft deployment in landing zones 2 versus 3.”

SVS reported that in the study, Dr. Panneton and colleagues performed a retrospective chart review from a single center of adult patients who underwent TEVAR for complicated aTBAD within 6 weeks of diagnosis. Patients included in the review were treated from January 2008 to December 2018. Reviewers excluded patients with previous type A repair and connective tissue disorders.

As summarized in the SVS press release, the review was composed of 83 patients, with a mean age of 60 ± 12 years and an average time to TEVAR of 4 ± 8 days. The patient data were evaluated and separated into three study groups based on landing zone: Zone 3 (Z3; n = 35); Zone 2 (Z2; n = 48 with left subclavian artery covered [Z2C, n =10] and left subclavian revascularized [Z2R, n = 38].

The findings reported in JVS included the following:

• Imaging evaluation revealed that only 11% of the study population had > 2 cm of healthy descending aorta to land the TEVAR
• 30-day survival (overall, 88%) did not differ between the groups: Z3, 89%; Z2C, 80%; Z2R, 90% (P = .6)
• Postoperative spinal cord injury differed between the groups: Z3, 0%; Z2C, 20%; Z2R, 2.6% (P = .012)
• Subsequent retrograde aortic dissection was observed in three (4%) patients: one in Z2 and two in Z3
• The overall aortic reintervention rate at 36 months after TEVAR differed significantly between the Z3 and Z2 groups (31% vs 10%; P = .25)

The investigators concluded that in patients treated for complicated aTBAD, Z2 TEVAR is associated with a lower need for aortic reintervention and aortic-related adverse events as compared to Z3 TEVAR. Additionally, they suggest that patients may benefit from a more aggressive proximal landing zone with similar perioperative morbidity when Z2 TEVAR is done with left subclavian artery revascularization.

Dr. Panneton explained these findings in the SVS press release:

In the SVS press release, the JVS editors advised that many technical details must be considered to achieve excellent outcomes in this difficult patient population. The editors stated, “Strong consideration for landing the TEVAR in Zone 2, including subclavian artery revascularization, appears important to better long-term outcomes.”