Left subclavian artery coverage during endovascular repair of thoracic aorta injury in trauma and non-trauma patients

Hemodynamic changes for half cover left subclavian artery ostium during thoracic endovascular aortic repair

Purpose

Some clinicians use endografts to cover half the left subclavian artery (LSA) ostium to cure some cases with insufficient proximal landing zone (PLZ) in thoracic endovascular aortic repair (TEVAR) treatment. We used computational fluid dynamics (CFD) to study the hemodynamic changes in the LSA because they may cause acute thrombosis or arteriosclerosis.

Methods

The digital model of the aortic arch was established and named model A, which only included the supraarch branch of the LSA. By directly covering half of the LSA ostium, which was named as model B. All established models were imported into the Gambit grid division software for grid division and were subsequently imported into the Fluent software for hemodynamic numerical simulation and calculation to analyze the related changes in LSA hemodynamic parameters after stent implantation.

Results

Under the same aortic inlet flow, in model B, the local blood flow velocity of the LSA ostium increased and the whole blood flow velocity at the distal end decreased. The average wall shear stress (WSS) of the LSA was significantly decreased. Meanwhile there was an obvious turbulent flow in the LSA lumen, and the related blood flow state was disordered.

Conclusion

CFD research confirmed that the implantation of an endograft covering half the LSA ostium can cause obvious hemodynamic changes, which is likely to cause a long-term arteriosclerosis or acute thrombosis of the LSA, finally increasing the risk of stroke. Once this operation is performed in some specific clinical cases for simplicity and economy, it seems that we should actively antiplatelet and follow up regularly.

Initial Outcomes of the Gore TAG Thoracic Branch Endoprosthesis for Endovascular Repair of Blunt Thoracic Aortic Injury

BACKGROUND

Endovascular repair of blunt thoracic aortic injury (BTAI) has dramatically reduced the morbidity and mortality of intervention. Injuries requiring zone 2 coverage of the aorta traditionally require left subclavian artery (LSA) sacrifice or open revascularization. Furthermore, these injuries are associated with an increased risk of in-hospital mortality and long-term morbidity. Here we report 1-year outcomes of total endovascular repair of BTAI with the GORE® TAG® Thoracic Branch Endoprosthesis for LSA preservation.

METHODS

Across 34 investigative sites, 9 patients with BTAI requiring LSA coverage were enrolled in a nonrandomized, prospective study of a single-branched aortic endograft. The thoracic branch endoprosthesis device allows for graft placement proximal to the LSA and incorporates a single side branch for LSA perfusion.

RESULTS

This initial cohort included 8 male and 1 female patient with a median age of 43 (22, 76) and 12 months of follow-up. Five total years of follow-up are planned. All participants had grade 3 BTAI. All procedures took place between 2018 and 2019. The median injury severity score was 2 (0, 66). The median procedure time was 109 min (78, 162). All aortic injuries were repaired under general anesthesia and with heparinization. A spinal drain was used in one patient. Post-deployment balloon angioplasty was conducted in one case at the distal landing zone. There was one asymptomatic LSA branch occlusion 6 months after repair. It was attributed to the purposeful proximal deployment of the branch stent to accommodate an early vertebral takeoff. The occlusion did not require revascularization. There were no strokes, mortalities, or aortic adverse events (migration, endoleak, native aortic expansion, dissection, or thrombosis) through 12 months of follow-up.

CONCLUSIONS

Initial cohort outcomes suggest that endovascular repair of zone 2 BTAI is feasible and has favorable outcomes using the thoracic branch device with LSA preservation. Additional cases and longer-term follow-up are required for a definitive assessment of the device's safety and durability in traumatic aortic injuries.

The impact of urgency of repair on outcomes following thoracic endovascular aortic repair for blunt thoracic aortic injury

OBJECTIVE

Current societal recommendations regarding the timing of thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI) vary. Prior studies have shown that elective repair was associated with lower mortality after TEVAR for BTAI. However, these studies lacked data such as Society for Vascular Surgery (SVS) aortic injury grades and TEVAR-related postoperative outcomes. Therefore, we used the Vascular Quality Initiative registry, which includes relevant anatomic and outcome data, to examine the outcomes following urgent/emergent (≤ 24 hours) vs elective TEVAR for BTAI.

METHODS

Patients undergoing TEVAR for BTAI between 2013 and 2022 were included, excluding those with SVS grade 4 aortic injuries. We included covariates such as age, sex, race, transfer status, body mass index, preoperative hemoglobin, comorbidities, medication use, SVS aortic injury grade, coexisting injuries, Glasgow Coma Scale, and prior aortic surgery in a regression model to compute propensity scores for assignment to urgent/emergent or elective TEVAR. Perioperative outcomes and 5-year mortality were evaluated using inverse probability-weighted logistic regression and Cox regression, also adjusting for left subclavian artery revascularization/occlusion and annual center and physician volumes.

RESULTS

Of 1016 patients, 102 (10%) underwent elective TEVAR. Patients who underwent elective repair were more likely to undergo revascularization of the left subclavian artery (31% vs 7.5%; P < .001) and receive intraoperative heparin (94% vs 82%; P = .002). After inverse probability weighting, there was no association between TEVAR timing and perioperative mortality (elective vs urgent/emergent: 3.9% vs 6.6%; odds ratio [OR], 1.1; 95% confidence interval [CI], 0.27-4.7; P = .90) and 5-year mortality (5.8% vs 12%; hazard ratio [HR], 0.95; 95% CI, 0.21-4.3; P > .9).Compared with urgent/emergent TEVAR, elective repair was associated with lower postoperative stroke (1.0% vs 2.1%; adjusted OR [aOR], 0.12; 95% CI, 0.02-0.94; P = .044), even after adjusting for intraoperative heparin use (aOR, 0.12; 95% CI, 0.02-0.92; P = .042). Elective TEVAR was also associated with lower odds of failure of extubation immediately after surgery (39% vs 65%; aOR, 0.18; 95% CI, 0.09-0.35; P < .001) and postoperative pneumonia (4.9% vs 11%; aOR, 0.34; 95% CI, 0.13-0.91; P = .031), but comparable odds of any postoperative complication as a composite outcome and reintervention during index admission.

CONCLUSIONS

Patients with BTAI who underwent elective TEVAR were more likely to receive intraoperative heparin. Perioperative mortality and 5-year mortality rates were similar between the elective and emergent/urgent TEVAR groups. Postoperatively, elective TEVAR was associated with lower ischemic stroke, pulmonary complications, and prolonged hospitalization. Future modifications in society guidelines should incorporate the current evidence supporting the use of elective TEVAR for BTAI. The optimal timing of TEVAR in patients with BTAI and the factors determining it should be the subject of future study to facilitate personalized decision-making.