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Trauma associated with the anatomical variation of thoracic great vessels
(Portuguese PDF version)

Ricardo Costa-Val¹, João Batista de Rezende-Neto², Leonardo P. Q. Silva³, Eduardo Vergara Miguel⁴, Tatiana Karina De Puy e Souza⁵

1. PhD student in Surgery, Universidade Federal de Minas Gerais (Brazil). Cardiovascular surgeon, Department of Trauma, Hospital João XXIII/FHEMIG, Belo Horizonte, MG, Brazil.
2. PhD in Surgery, Universidade Federal de Minas Gerais (Brazil). General surgeon, Department of Trauma, Hospital João XXIII/FHEMIG, Belo Horizonte, MG, Brazil.
3. General surgeon, Department of Trauma, Hospital João XXIII/FHEMIG, Belo Horizonte, MG, Brazil.
4. Vascular surgeon, head of the Service of Cardiovascular Trauma at Hospital João XXIII/FHEMIG, Belo Horizonte, MG, Brazil.
5. Undergraduate student in Medicine, Faculdade de Barbacena, Barbacena, MG, Brazil.

Correspondence:
Ricardo Costa Val
Rua Aimorés, 612/1103
CEP 30140-070 - Belo Horizonte - MG, Brazil
Tel.: +55 31 9972.6066/3224.2974
E-mail: costaval@mkm.com.br

J Vasc Br 2004;3(1):81-2

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PART II - WHAT WAS ACTUALLY DONE

After discussing the case, we opted for a conservative approach (monitoring the case), given that the patient was stable, lucid and was in a hospital specialized in trauma, which could provide surgical treatment at any time if it was necessary. A study of the aortic arch was required, evidencing absence of vascular lesions and anatomical variation of subclavian arteries, described as follows: the first branch of the ascending thoracic aorta was the right common carotid artery, the second branch was the left common carotid artery and the third branch was a whole arterial trunk, from which the right subclavian artery and the left subclavian artery emerged. The great deviation of the trachea to the right was due to the right subclavian artery, which crossed the whole mediastinum. The bullet was near the aortic arch (Figure 2).

Figure 2 - Aortography evidencing anatomical variation of subclavian arteries: right common carotid artery in the first branch of the ascending aorta, left common carotid artery in the second branch and a whole arterial trunk in the third branch, from which the right subclavian artery (crossing the mediastinum) and left subclavian artery emerged. There were no signs of vascular lesion, despite the location of the bullet.

DISCUSSION

As Saeed et al.¹ and Rich & Spencer² reported, anatomical variations of subclavian arteries are rare and of small clinical importance. However, they are a great challenge to surgeons, particularly in situations which involve a suspicion of vascular trauma. Another type of vascular lesion which is still discussed in medical literature and which also poses a great challenge to surgeons is minimal vascular lesions. For Mattox & Hirshberg,³ such lesions mainly are small arteriovenous lesions, minor pseudoaneurisms and dissection and obstruction caused by physical aggression (such as described above) and of which natural history is not completely known. In the latter case, once the major vascular lesion is not confirmed, the main concern is the possibility of the gunshot having burned the arterial wall, leading to complications in the future. Up to the present moment, the authors recommend a serial follow-up of these patients through angiography.

In their high-quality review article, Chiesa et al.⁴ discussed the importance of initial findings in cases of suspicion of blunt trauma of the thoracic aorta. Their observations are similar to those described by Mattox & Wall,⁵ who analyzed lesions to thoracic great vessels in general. In both studies, the authors recommend the use of chest radiography, which is an excellent method for initial diagnosis given that it have high rates of sensitivity and of negative predictive value for the presence of mediastinal hemorrhage, even though it cannot confirm this diagnosis. Another method for initial examination which is of great value is transesophageal echocardiogram, a procedure which presents several advantages, such as: it can be performed in unstable patients under surgery and general anesthesia; and it has good sensitivity to cardiac lesions and lesions to the ascending aorta. Magnetic resonance imaging, in its turn, can achieve rates similar to those of contrast computed tomography, but it cannot be performed in unstable patients and access to it is still quite limited in our milieu. For cases of stable patients with suspected vascular lesion in this area, instead of contrast tomography of the chest, the first options preferably are angiotomography and aortography. In our service, patients are evaluated together with the general surgeon, according to the ATLS® protocol, which is a reference for all professionals involved in treating a traumatized patient. All patients also undergo an upper digestive endoscopy and/or contrast examination of the esophagus, in order to rule out lesions in other structures in this region.

CONCLUSION

Vascular trauma of thoracic vessels is still a major challenge to modern medicine. The conservative treatment reported in part I was crucial for the complete recovery of the patient and demonstrated that worse than the physical aggression of the gunshot was the possibility of iatrogenic consequences of an unnecessary surgical intervention in a stable patient, for which appropriate diagnostic procedures had not been conclusive. Anatomical variations, despite being rare, such as in the case reported, are a natural phenomenon in the human species and may turn into great diagnostic challenges.

REFERENCES

1. Saeed M, Rufai AA, Elsayed SE, Sadiq MS. Variations in the Subclavian-axillary arterial system. Saudi Med J 2002;23(2):206-12.

2. Rich NM, Spencer FC. Subclavian artery injuries. In: Rich NM, Spencer FC, editors. Vascular Trauma. Philadelphia, PA: W. B. Saunders; 1978. p. 307-329.

3. Mattox KL, Hirshberg A. Traumatismo vascular. In: Haimovici H, Ascer E, Hollier LH, Strandness Jr. DE, Towe JB. Cirurgia Vascular - Princípios e Técnicas. 4ª ed. Rio de Janeiro: DiLivros; 1996. p. 480-96.

4. Chiesa R, Moura MRL, Lucci C, Castellano R, Civilini E, Melissano G, Tshomba Y. Blunt trauma of the thoracic aorta: mechanisms involved, diagnosis and management. J Vasc Br 2003;2(3):197-210.

5. Mattox KL, Wall MJ Jr. Injury to the thoracic great vessels. In: Feliciano DV, Moore EE, Mattox KL, editors. Trauma. 3rd ed. Stamford, CT: Appleton & Lange; 1996. p. 423-440.