Penetrating traumatic aortic arch injury: a unique case report presentation

Abstract

Introduction:

Penetrating traumatic aortic arch injuries are rare due to the protective effect of surrounding structures. The choice between open surgical repair and endovascular repair depends on several factors including the patient’s hemodynamic status, anatomical considerations, and available expertise. However, these injuries remain associated with significant mortality, emphasizing the need for swift intervention and careful patient selection. Long-term follow-up is also essential to monitor potential complications such as stent migration or endoleaks in cases managed with endovascular repair.

Importance:

This case report highlights the challenges in managing delayed presentations of penetrating traumatic aortic arch injuries, emphasizing the importance of a multidisciplinary approach and the potential for nonoperative management in carefully selected patients.

Case presentation:

A 38-year-old male presented to a regional hospital 1 day after sustaining a left precordial stab wound. Initial assessment revealed hemodynamic instability (hypotension, tachycardia), and a left-sided hemothorax requiring drainage. Imaging (chest X-ray, computed tomography [CT] angiography) revealed an acute traumatic aortic injury involving the distal aortic arch near the left subclavian artery origin, characterized by an intimal flap, mural thrombus, a small pseudoaneurysm, and a mediastinal hematoma.

Clinical discussion:

After stabilization and transfer to a Level 1 trauma center, the patient was managed conservatively with serial CT angiography monitoring. Over a period of several weeks, the pseudoaneurysm remained stable without evidence of expansion, ultimately leading to successful nonoperative management. The patient was discharged with ongoing outpatient follow-up.

Conclusion:

This case demonstrates the successful nonoperative management of a delayed presentation of penetrating traumatic aortic arch injury. Careful patient selection, close multidisciplinary monitoring, and serial imaging are essential components of this approach. While this less invasive strategy avoids the risks associated with open or endovascular procedures, close monitoring for complications and timely intervention remain critical for optimal outcomes. Further research is needed to better define the indications for and outcomes of conservative management in such cases.

Background

Traumatic penetrating aortic arch injuries are rare occurrences, accounting for a small fraction of all aortic injuries. Their low incidence is attributed to the protection provided by surrounding structures, making direct injury to the aortic arch less common than in other anatomical regions^[1^]. However, despite their rarity, the severity of these injuries cannot be understated. The clinical presentation often involves a combination of symptoms, including chest pain, dyspnoea, hypotension, and shock^[1^]. Early recognition and accurate diagnosis are critical for timely intervention. Recent studies have highlighted the importance of comprehensive screening protocols to identify hemodynamically stable patients who might benefit from further evaluation for blunt aortic injuries^[2^].

HIGHLIGHTS

• Successful nonoperative management: Demonstrates the feasibility and potential benefits of a conservative approach in carefully selected patients with penetrating traumatic aortic arch injury. This contrasts with the typical need for surgical or endovascular intervention.

• Emphasis on patient selection and monitoring: Underscores the importance of stringent patient selection criteria for nonoperative management and the crucial need for close and vigilant monitoring for complications.

• Significant clinical relevance: Offers valuable insights into the management of a challenging and rare condition, contributing to a better understanding of this life-threatening injury and advancing treatment approaches.

The management of traumatic penetrating aortic arch injuries poses substantial challenges due to the complex anatomical location and potential associated injuries^[3^]. Surgical intervention remains the cornerstone of treatment. The choice between open and endovascular repair depends on various factors, including the patient’s hemodynamic status, anatomical considerations, and the available expertise and resources^[3^]. Open repair involves direct surgical access to the aortic arch, allowing for meticulous repair of the injury site^[3^]. On the other hand, endovascular repair offers a less invasive alternative, particularly suitable for patients who are not optimal candidates for open surgery^[3^].

Emerging evidence suggests that both approaches yield favorable outcomes when applied judiciously^[1^]. Early repair, whether open or endovascular, has been associated with improved survival rates and reduced morbidity in appropriately selected patients. Despite advancements in diagnosis and treatment, traumatic penetrating aortic arch injuries remain associated with high mortality rates^[2^]. This underscores the critical nature of these injuries and the need for swift and accurate intervention. Factors influencing outcomes include the patient’s overall health, concomitant injuries, the time elapsed from injury to treatment, and surgical approach^[3^].

Long-term follow-up studies are essential to evaluate the durability of endovascular repairs and to monitor potential complications such as stent migration or endoleaks^[4^]. Additionally, ongoing research into minimally invasive techniques, advanced imaging modalities, and patient-specific risk stratification will likely contribute to further improvements in outcomes^[4^].

In keeping with the above, traumatic penetrating aortic arch injuries are rare but life-threatening events that demand prompt diagnosis and appropriate management. Despite their rarity, these injuries highlight the need for a multidisciplinary approach, encompassing trauma surgeons, vascular surgeons, and interventional radiologists^[5^]. With advancements in surgical techniques and diagnostic tools, outcomes for these injuries are gradually improving. However, continued research and collaboration are essential to refine protocols, enhance patient selection, and optimize long-term results.

We present a unique case of delayed presentation of penetrating aortic arch injury as a result of a precordial stab wound, which was successfully managed nonoperatively with the use of repeated computed tomography (CT) angiogram. Management was conducted in accordance with institutional protocols approved by the Human Research Ethics Committee (M2410116).

Case report

A 38-year-old male was seen at a regional hospital in Johannesburg, South Africa, 1 day after sustaining a left precordial stab wound in the left third intercostal space medial to the midclavicular line. On arrival, the patient was conscious, with a patent airway and spontaneous breathing. Circulation was compromised as evidenced by hypotension (BP 70/39 mmHg) and tachycardia (heart rate [HR] 118 bpm), with clinical signs of a left-sided hemothorax. His initial arterial blood gas demonstrated a metabolic acidosis, and he was resuscitated with 1 L of warm crystalloids. Initial blood tests revealed a hemoglobin of 8.6 g/dL, platelet count of 206, and a normal international normalisation rate of 1.1. Followed by a balanced blood transfusion consisting of two units of packed red blood cells and two units of fresh frozen plasma (FFP). This informed the balanced transfusion approach using two units packed red blood cells and two units FFP (1:1 ratio). A bedside chest X-ray (CXR) (Fig. 1) confirmed a left-sided hemothorax. Subsequently, a left-sided intercostal drain (ICD) was placed, which immediately drained 900 mL, followed by a second ICD placement. The patient responded to resuscitation with improvement in blood pressure to 110/70 mmHg and heart rate to 88 bpm.

Figure 1.

Baseline supine bedside CXR demonstrates veiling of the left hemithorax with contralateral mediastinal and tracheal shift consistent with a large left hemothorax. There is a widened mediastinum.

While still at the regional hospital, a baseline CT Angiogram of the chest (Fig. 2) was then ordered, which demonstrated an acute traumatic aortic injury of the caudal aspect aortic arch just proximal to the left subclavian artery (SCA) origin, with an intimal flap and mural thrombus, and a small pseudoaneurysm, associated with a mediastinal hematoma and residual left hemothorax.

Figure 2.

Traumatic aortic pseudoaneurysm and associated injuries. Axial CT angiogram of the chest demonstrates a small pseudoaneurysm (white arrow) and mural thrombus (black arrow) of the aortic arch, with associated mediastinal hematoma (asterisk) and left hemothorax (star).

The patient was subsequently referred to our level one trauma facility on day 3 post-injury for trauma surgery review. On arrival at our facility’s trauma emergency department, the patient remained hemodynamically stable with two left-sided ICDs. The patient had a persistent asymptomatic anemia of 8.6 g/dL, but remained asymptomatic, with no tachycardia, hypotension, or signs of tissue hypoxia. A repeat CTA chest (Fig. 3) was ordered and performed approximately 48 hours after the baseline CTA. This revealed a persistent pseudoaneurysm and intimal flap with a floating intraluminal thrombus of the aortic arch, with an improvement of the mediastinal hematoma and left hemothorax. The floating intraluminal thrombus was closely monitored with serial CTA imaging. Given its stability and absence of distal embolization or ischemic symptoms, anticoagulation was not initiated due to the risk of exacerbating the associated pseudoaneurysm. Multidisciplinary consensus favored conservative observation.

Figure 3.

Acute traumatic aortic injury and mediastinal hematoma. Interval CTA chest done at 24 hours post-baseline, axial (a), coronal (b) and sagittal, (c) plane images demonstrate a persistent pseudoaneurysm (white arrow) from the left ventrolateral border of the aortic arch, at the level just proximal to the left subclavian artery origin (star). There is an associated intimal flap and floating intraluminal thrombus (black arrow) at the caudal aspect of the arch at the level of the left SCA origin (star). Also demonstrated: (a) Residual mediastinal hematoma (H) and shallow residual left hemothorax with two ICDs.

The patient was consequently admitted to the cardiothoracic intensive care unit (ICU) for conservative (nonoperative) management and a plan for repeat CTA chest 2 weeks later (day 16 post-injury). The patient’s ICU stay was uneventful. His blood pressure was controlled using oral antihypertensives (Enalapril and Carvedilol), aiming for systolic BPs <120 mmHg. The ICDs were removed after drainage tapered sufficiently on days 6 and 7 post-injury.

Figure 4: Planned repeat CTA imaging of the chest was performed on day 14 of admission (17 days post-injury). This revealed persistent aortic arch pseudoaneurysm with a residual intimal flap but resolution of the floating mural thrombus, improvement of the mediastinal hematoma, and a focal small collection along the previous anterior ICD tract. The patient was consequently discharged home with follow-up and surveillance in the surgical outpatient department for review and to monitor the pseudoaneurysm.

Figure 4.

Interval CTA chest done 2 weeks after injury, axial (a), coronal (b), and sagittal (c) plane images demonstrate persistent aortic arch pseudoaneurysm (white arrows). There is a residual intimal flap with resolution of the luminal thrombus (black arrow). Residual mediastinal hematoma (H) and hemothorax (E) are also demonstrated.

Discussion

Nonoperative management of penetrating traumatic injury to the aortic arch is a complex topic, often requiring a multidisciplinary approach. Rapid assessment and stabilization are crucial, and this involves monitoring vital signs, obtaining intravenous access, and providing resuscitation as needed^[6^]. Imaging techniques like CT angiography to assess the extent of injury is essential^[7^]. Patients may then be closely monitored in an ICU setting with continuous cardiac and respiratory monitoring^[6^]. Control of blood pressure is vital, and this can involve the use of medications such as beta-blockers to reduce aortic wall stress and prevent further injury^[8^]. Fluid resuscitation must be carefully managed to avoid overload, especially if there is a risk of cardiac tamponade^[8^]. Patients should be monitored for signs of complications, including aneurysm formation, hemorrhage, or signs of organ ischemia due to disrupted blood flow^[9^]. In some cases, endovascular repair techniques may be considered, particularly for patients who are not surgical candidates due to comorbidities or other factors^[10^]. Stenting can be a less invasive alternative and may help control hemorrhage or repair the vessel^[11^]. Regular follow-up with imaging studies, particularly CT angiography, is essential to monitor for late complications like pseudoaneurysm formation^[12^].

The prognosis for patients with penetrating aortic arch injuries varies widely based on factors like the severity of the injury, the presence of other injuries, and the overall stability of the patient^[13^]. Studies indicate that patients managed nonoperatively who are hemodynamically stable may have a reasonable chance of survival, particularly if they can be closely monitored^[13^]. Nonoperative management can lead to approximately 30%–60% survival rates in select populations, depending on injury characteristics and patient factors^[14^]. The development of complications may impact long-term survival; thus, continuous follow-up is essential^[14^].

As the case discussed above demonstrates, it is possible to manage such complex penetrating aortic arch injuries nonoperatively, provided the patient is hemodynamically stable. The decision for conservative management was based on the patient’s hemodynamic stability at the time of tertiary review, absence of ongoing bleeding, stable imaging findings, and multidisciplinary input involving trauma, cardiothoracic, and vascular teams. A patient would require management in an ICU setting along with daily (or twice daily) hemoglobin checks, chest physio for management of the hemothorax, and a repeat CT Angiogram within 7–10 days post the initial CT angiogram. This repeat imaging is to accurately assess the resolution, or progression, of the initial features of injury, namely, intimal flap, pseudoaneurysm, mural thrombus, and mediastinal hematoma. Repeat imaging prior to discharge is also recommended. If at any point the patient becomes hemodynamically unstable, access to theatre (and cardiac bypass) must be readily available.

Conclusion

Nonoperative management of penetrating aortic arch injuries is a nuanced approach that requires careful patient selection, thorough monitoring, and an adaptable treatment plan. While outcomes can vary significantly, advances in imaging and management strategies have improved select patients’ prognoses, highlighting the importance of individualized care. Regular follow-up is essential to address potential complications and ensure optimal recovery.

Ethical approval

Ethical approval for this study (Wits Health Consortium: 31 Princess of Wales, Parktown) was provided by the Human Research Ethics Committee of the University of the Witwatersrand, Johannesburg, South Africa on 22 January 2025. Ethics protocol number: M2410116.

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Sources of funding

Not applicable.

Author contributions

All listed authors contributed equally to the paper according to: study design, data collection data analysis, and writing the paper.

Conflicts of interest disclosure

Not applicable.

Research registration unique identifying number (UIN)

National Health Research Database, GP202411039, https://nhrd.health.gov.za.

Guarantor

Rudo Pswarayi.

Provenance and peer review

Not applicable.

Data availability statement

No datasets were generated or analyzed during this study.