Given the 46% mortality rate noted in non-operatively managed patients with TAIR (26), the SVS committee suggested urgent (<24 h) repair simultaneously or immediately after other injuries have been addressed, but at the latest prior to hospital discharge (27, 31). In some series, TAIR patients underwent delayed TEVAR up to 7–14 days after sustaining the injury and the published data is promising, although the small number of patients in these series might bias the results (32). Expectant strategy with thorough imaging surveillance and proper pharmaceutical treatment might be appropriate for “minimal aortic injury” cases showing limited periadventitial defect or hematoma (32, 33). ESVS suggests that delayed aortic repair for TAIR should be considered only in patients with periaortic hematoma less than 15 mm and when no rupture is present, but better evidence is necessary to support this suggestion (Class IIa, Level C) (29). In contrast with open aortic surgery, TEVAR can be performed in both stable and unstable patients with high technical success rates and good results, making it an attractive modality for unstable patients who urgently need to undergo TEVAR (34).

The timing of aortic repair in patients with TAIR in relation to other injuries should also be addressed. In the majority of TAIR cases, lung contusion, rib fractures, and limb injuries are also present and these can be addressed after the aortic repair (32, 35). Life-threatening injuries such as central neural system damage and/or other uncontrolled bleeding should be addressed probably before any aortic repair. Published data is scarce and more is necessary to answer the question of in what order injuries should be treated in relation to aortic repair.

This dilemma has also been addressed by the relevant SVS Committee, which underlined that in acute situations, such as TAIR, patient’s age should not play a significant role in decision-making on the type of repair. Despite the fact that younger patients have been reported to present with a higher risk for late complications, the lower mortality and SCI incidence after TEVAR compared to open repair render these long-term postoperative considerations insignificant (25, 36, 37). On the other hand, younger or fit patients with aortic anatomy unsuitable for TEVAR should consider undergoing open repair (27, 29). To date, it has been accepted that endovascular repair does not have a role in children and teenagers (38). The mismatch between vessel diameter and available stent sizes; the smaller arteries for access and the necessity for surgical exposure of the iliac artery; and finally, the fact that vessels of young individuals will outgrow the placed stents are some of the problems of endovascular repair in children and teenagers. These difficulties may lead vascular surgeons to think twice before proceeding to endovascular repair of isthmic ruptures in such young patients, but successful aortic repair with balloon-expandable stents has already been reported (38).

Most of the TAIR patients are of young age, usually younger than 40 years (26). With age, the aorta goes through normal changes such as diameter expansion and decrease of the aortic arch angulation. Available thoracic endografts have been developed to treat aneurysmal disease as they were designed to, and, therefore, they are suitable for larger aortic diameters and less angulated aortic arches. As a result, the “off-label” use of available thoracic endografts in TAIR cases may have anatomic limitations. Poor adaptation of a stent-graft to increased arch angulation could result in bad apposition and sealing, leading to endoleak and migration or collapse of the stent-graft (35, 39). Stent-graft collapse is a life-threatening complication that could lead to acute aortic occlusion and distal organ malperfusion (22). In TAIR cases after TEVAR, stent-grafts are more prone to collapse due to their larger size compared to the smaller aortic diameter of younger patients as mentioned above. Additionally, hypovolemic shock in trauma patients resulting in vasospasm and cyclic diameter variation of 10–20% in synchronization with the heart cycle can result in significant underestimation of the “real” aortic diameter and inaccurate preoperative stent-graft measurements (35, 40). More aggressive oversizing should be applied in gravely hypotensive patients, but it should not exceed 20% (29). All the above pose additional difficulties to optimal stent-graft sizing in TAIR, but endovascular bioengineers have already started to address the need of thoracic endografts that could fit TAIR patients (41).

Two of the most controversial issues related to TEVAR is the coverage of the LSA and whether routine or selective LSA revascularization should be preferred. In TAIR cases, the landing zone requirements for TEVAR are different to that of thoracic aneurysmal disease, but the proximity of the isthmic injury to the LSA origin makes coverage necessary in up to 50% of TAIR patients (26, 42, 43). Distal arm ischemia, possible vertebrobasilar pathology, and possible occlusion of thyrocervical collateral arteries to anterior spinal arteries increase the risk of SCI occurrence after LSA coverage. To date, no clear consensus regarding preoperative LSA revascularization has been reached and published data are controversial. Some authors suggest LSA coverage when necessary and expectant strategy, and others suggesting the opposite (32, 35, 44). Suggested indications include patent left internal mammary artery to left anterior descending coronary artery bypass or any anatomic variation that renders a patent left vertebral artery necessary. In any case, decision should be made on an individual basis and take into account the level of expertise in either open or endovascular technique, the patient’s general condition, and the presence of concomitant injuries (27, 45).

Open TAIR repair with cardiopulmonary bypass requires a large dose of systemic heparin to perform; a disadvantage that TEVAR does not have. Published data partially support performing TEVAR without the use of heparin in TAIR cases with presence of grave concomitant injuries and high risk for bleeding (13, 46). On the other hand, the majority of currently available sheaths are 22–24 F in diameter and occlude the blood flow at the access vessel. Without the use of heparin, this diminished blood flow caused by the sheath could potentially lead to lower limb ischemia, especially when TEVAR procedural time is prolonged by less experienced operators. Routine heparinization in these cases is frequently based on local experience, as available evidence is very limited. Individualizing the decision and balancing the thrombophylic and hemorrhagic potential of each particular patient is currently suggested (27, 32).

Spinal cord ischemia occurs rarely (3%) after TEVAR for traumatic aortic rupture, significantly lower than open thoracic aortic repair (26, 47). To our opinion, routine CSF drainage is not justified by a number of characteristics of TEVAR for TAIR, such as the limited length of the covered thoracic aorta and the substantial risk of epidural bleeding in the multi-trauma patient, who frequently presents with synchronous coagulopathy. CSF drainage should be considered only in the presence of SCI symptoms (27). Recognizing signs of SCI in a multi-trauma patient who possibly presents with concomitant TAIR and central and/or peripheral neural system trauma can be challenging, therefore, an objective diagnostic and treatment algorithm should be developed.

Despite the fact that TEVAR could be performed under local anesthesia in elective cases, in emergency settings with a multi-trauma patient who is often agitated, non-cooperative, and presents with a number of concomitant injuries of various gravity, local anesthesia is less favorable. Published data support that TEVAR for TAIR should always be performed under general anesthesia (27).

The ideal strategy for long-term follow-up of TAIR patients after TEVAR is still in evolution. Annually performed CTA control for life is considered the best method for elective TEVAR surveillance, but this strategy might not suit patients who underwent TEVAR for TAIR. Opposite to the nature of degenerative thoracic aortic aneurysms, TAIR is not an evolving aortic disease process, but rather a stable injury as a direct result of trauma. Despite current guidelines suggesting the contrary, annual CTA might not be mandatory if TEVAR in TAIR cases is successfully completed and no complications occurred in the short- and midterm follow-up periods (28). The RESCUE trial results suggest that annual follow-up is mandatory only for a period of 5 years (48). This becomes more important given, the younger age of these patients, and the concerns of cumulative radiation and iodinated contrast exposure (49, 50). Other alternative follow-up strategies have been suggested, such as the combination of plain X-ray and MRA that could be of benefit for the long-term surveillance of these patients (28). Follow-up timing and preferred imaging method after TEVAR in TAIR cases should be individualized, tailored, and adapted to the specific conditions of each particular patient.

Anatomic variations and anomalies of the arch and its branches are considered rare, but they are reported to reach as high as 15–34% in published TAIR case series (43). These variations include aberrant right subclavian artery, bovine arch type, Kommerell’s diverticulum, right-sided aortic arch, left vertebral artery, and others. Endovascular specialists should carefully examine the pre-procedural CTA in order to recognize aortic arch anomalies or variations, and consequently avoid complications such as cerebrovascular events, endoleaks, upper extremity ischemia, and SCI. Customized TEVAR materials can address difficult aortic anatomies in elective cases, but in the emergency settings of TAIR, customization is not possible. Therefore, in patients presenting with TAIR and existing arch variations, TEVAR might not be a technically feasible solution, leaving open or hybrid repairs the only way to address the aortic trauma (43).