Traumatic rupture of the thoracic aorta due to closed-chest trauma

EDITORIAL

Associate professor, Vascular Surgery, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil

It is likely that any area in vascular surgery or trauma surgery has been so benefited over the past years as the diagnosis and treatment of traumatic lesions of the thoracic aorta due to closed–chest trauma. If, on the one hand, laws have been implemented to make protection methods in frontal motor vehicle collisions mandatory – such as the use of the safety belt, the use of inflatable devices, known as air bags, and deformable body structures that absorb impact. On the other hand, new habits were created in large cities, such as the use of motorcycles for fast deliveries and high impact and energy sports, known as radical sports, which involve sudden acceleration and deacceleration and falls under high speeds, maintaining a high prevalence of these lesions.¹

Although protection mechanisms have been incresingly more used, traumatic lesion of the thoracic aorta is the second most common cause of death due to closed trauma (15–20% of deaths) in the USA, resulting in a high prehospital mortality rate, with around 90% of patients dying at the accident site.²

In the metropolitan area of São Paulo, there were, according to the Brazilain Unified Health System Database (DATASUS³), 1,460 deaths due to traffic accidents between October 2005 and September 2006. This is the most recent data and about 180 to 300 deaths are related to aortic lesions. This high mortality rate shows that there is the need of improving the systems of rescue and prehospital care in our urban centers, as well as the early recognition of these patients and their referral to proper centers.

However, there is a group of patients that survive the initial trauma and present hemodynamically stable with contention of the aortic lesion by underlying structures, allowing to establish a diagnosis and perform the treatment. The main signs guiding the diagnosis of aortic lesions are the information of the lesion mechanism (when it involves frontal impact and deacceleration), the association of spinal trauma, thoracic and sternal excoriations and fracture of the costal archs, especially of the first rib. The diagnostic methods are widely approached in the review performed by Drs. Vishal Bansal, Jeanne Lee and Raul Coimbra, who draw attention to the suspicion based on the information of the trauma mechanism.⁴

The severity of a multisystemic trauma and its relationship with mortality and morbidity can be seen by trauma indexes. In a previous series, published in this journal by Miotto Neto et al.,⁵ there was a mean injury severity score (ISS) of 42.1, with two deaths in 11 patients submitted to surgery. This high ISS was associated with severe multisystemic lesions. In this series, one death was a direct consequence of aortic lesion, but the other patient, after a successful endovascular repair, died of severe lung and cervical spine contusion.

Over the past 10 years, two factors have contributed to the improvement in survival rates of patients with traumatic rupture of the aorta: First, the introduction and dissemination of the endovascular technique; second, the use of multichannel tomography scanners, which provide fast acquisition (up to 10 minutes in total), image definition and high sensitivity and specificity. This method is enough to identify the lesions and for treatment indication and planning, either operative or endovascular. In that article, Dr. Bansal highlights the comparative aspects of the growing importance of tomography and aortography. Aortography, in our opinion, is dismissed as a diagnostic method and is only used at the surgical center as part of the endovascular treatment.

Among the advantages we could perceive in the endovascular treatment is the fact that, at the same procedure, after the implantation, one can immediately proceed to the repair of associated abdominal, thoracic, neurological and orthopedic lesions, since the traumatic rupture is no longer the most important morbidity factor. The stent graft can be implanted without using anticoagulants, different from the open repair with or without bypass in the left femoral atrium. These factors, besides the short time needed for its execution, have made this the method of choice at Pronto–Socorro do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. There are also patients with severe hemodynamic instability and massive hemothorax, in which left thoracotomy or bilateral thoracotomy are the most freasible options to identify lesions and repair them. The article by Dr. Bansal presents criteria for contra–indication for surgery, which we suggest should be followed by other groups.

As to postoperative paraplegia, if one the one hand there is no consensus in the literature, on the other hand the results in our series, added by three cases since its publication, showed the superiority of the endovascular treatment in avoiding it. Other series show agreement with this observation.^6–9

In conlusion, the four basic points to improve the results of traumatic rupture of the aorta due to closed–chest trauma are:

– Fast identification, in which the information on the mechanisms involved in the trauma is important;

– Multislice tomography, quickly performed at the admission of risk patients for traumatic rupture of the aorta or in multiple trauma patients with mediastinal widening;

– Logistic conditions to perform the endovascular treatment of the traumatic ruptura of the aorta, which will certainly become the standard conduct for most cases, except for unstable patients and those with massiva hemothorax, which is opposed to some services;

– Early repair of visceral, orthopedic and neurological lesions.

References

1. McGwin G, Reiff DA, Moran SG, Rue LR. Incidence and characteristics of motor vehicle collision–related blunt thoracic aortic injury according to age. J Trauma. 2002;52:859–65.

2. Dosios TJ, Salemis N, Angouras D, Nonas E. Blunt and penetrating trauma of thoracic aorta and aortic arch branches: an autopsy study. J Trauma. 2000;49:696–703.

3. Brasil, Ministério da Saúde. Informações de saúde, estatísticas vitais mortalidade e nascidos vivos, mortalidade geral. Brasília: Ministério da Saúde. Disponível em: http://www.datasus.gov.br.

4. Bansal V, Lee J, Coimbra R. Current diagnosis and management of blunt traumatic rupture of the thoracic aorta. J Vasc Bras. 2007;6:64–73.

5. Mioto Neto B, Aun R, Estenssoro AEV, Puech–Leão P. Tratamento das lesões de aorta nos traumatismos torácicos fechados. J Vasc Bras 2005;4:217–26.

6. von Ristow A. Management of aortic lesions in blunt chest trauma. J Vasc Bras. 2005;4:215–6.

7. Ott MC, Stewart TC, Lawlor DK, Gray DK, Forbes TL. Management of blunt thoracic aortic injuries: endovascular stents versus open repair. J Trauma. 2004;56:365:70.

8. Kasirajan K, Heffernan D, Langsfeld M. Acute thoracic aortic trauma: a comparison of endoluminal stent grafts with open repair and nonoperative management. Ann Vasc Surg. 2003;17:589–95.

9. Gan JP, Campbell WA. Immediate endovascular stent graft repair of acute thoracic aortic rupture due to blunt trauma. J Trauma. 2002;52:154–7.

Traumatic rupture of the thoracic aorta due to closed–chest trauma

Ricardo Aun

Publication Dates

• Publication in this collection
  19 July 2007
• Date of issue
  Mar 2007