Lesões traumáticas do mediastino: aspectos na tomografia computadorizada

Abstract

As lesões traumáticas mediastinais constituem achados pouco freqüentes no trauma torácico, mas são de extrema importância, por representarem mau prognóstico, dada a sua gravidade e lesões associadas. O trauma mediastinal é cada vez mais diagnosticado pela tomografia computadorizada, em especial pelo rápido tempo de aquisição decorrente da técnica helicoidal, que permite a avaliação de pacientes em estado grave, possibilitando a adoção de conduta terapêutica eficiente. Os autores estudaram 11 pacientes com trauma torácico submetidos a tomografia computadorizada, os quais apresentaram lesões mediastinais. A hemorragia mediastinal representou a lesão mais comum nesta casuística, manifestando-se sob a forma de infiltração da gordura mediastinal, com a presença de material denso permeando os espaços mediastinais, ou sob a forma de hematoma. O hemopericárdio representou a segunda lesão mais comum, caracterizado por material denso ou líquido no interior do pericárdio. As lesões aórticas foram observadas em três casos, caracterizadas por irregularidade parietal no contorno aórtico ou por pseudo-aneurisma. Neste trabalho o trauma torácico fechado foi observado em seis casos, enquanto o trauma aberto ocorreu em cinco pacientes. As causas de trauma fechado foram atropelamento, colisão automobilística e queda de altura. A forma penetrante de traumatismo torácico decorreu de dois modos de agressão: lesão por arma de fogo e lesão por arma branca Unitermos: Hemorragia mediastinal; Lesão da aorta; Tomografia computadorizada. Traumatic mediastinal lesions: computed tomography findings.Traumatic mediastinal lesions are unusual findings in patients with thoracic trauma but may represent poor prognosis and be associated with severe lesions. Mediastinal trauma is increasingly being diagnosed by computed tomography due to the fast acquisition times of helical techniques, allowing the evaluation of critically ill patients and the adoption of efficient therapeutic measures. The authors studied 11 patients with mediastinal lesions who were submitted to computed tomography due to thoracic trauma. The most frequent finding was mediastinal bleeding characterized by infiltration of mediastinal fat, dense material within the mediastinal spaces or hematoma. Hemopericardium was the second most common lesion in this series, appearing as dense or liquid material in the pericardium. Aortic lesions such as wall irregularities or pseudoaneurisms were less commonly seen (three patients). In this study blunt thoracic traumas were observed in six cases whereas penetrating trauma occurred in five cases. The causes of blunt trauma were pedestrians struck by car, motor vehicle accidents and falls. Penetrating trauma was due to lesions produced by bullets or knifes.

Tomographic aspects of penetrating thoracic trauma: injuries from firearms and other weapons

“…In both of our cases, the lesion was in the left hemidiaphragm, with gastric herniation. Herniation of the stomach or colon into the thorax is the finding that is most characteristic of rupture of the left hemidiaphragm ( 4 , 19 , 20 ) . Because CT allows rapid, efficient diagnosis of diaphragmatic lesions, it facilitates early treatment, avoiding the need for late repair, which, due to the presence of fibrous tissue, can be more difficult ( 18 ) .…”

“…Because CT allows rapid, efficient diagnosis of diaphragmatic lesions, it facilitates early treatment, avoiding the need for late repair, which, due to the presence of fibrous tissue, can be more difficult ( 18 ) . Coronal and sagittal reconstructions increase the diagnostic accuracy of the method ( 4 , 19 , 20 ) . The co-occurrence of abdominal lesions and hemidiaphragm rupture has been reported in the literature ( 4 , 19 ) .…”

“…Coronal and sagittal reconstructions increase the diagnostic accuracy of the method ( 4 , 19 , 20 ) . The co-occurrence of abdominal lesions and hemidiaphragm rupture has been reported in the literature ( 4 , 19 ) . In our sample, we observed diaphragmatic rupture accompanied by hemoperitoneum in two cases and by splenic injury in one.…”

“…CT is quite effective in evaluating traumatic lesions of the skull, face, spine, thorax, abdomen, and pelvis, allowing a more detailed study of the injuries of victims of trauma and therefore playing an essential role at trauma centers ( 2 ) . Chest CT presents greater sensitivity and specificity than does chest X-ray in the detection and evaluation of the extent of traumatic injury to the lung parenchyma, pleural space, mediastinum, and diaphragm ( 4 , 5 ) .…”

Blunt thoracic trauma with the formation of pseudoaneurysm with the junction of the right subclavian artery

“…In general, traumas involving aorta and great mediastinal vessels add approximately 5% of incidents; however, there is a high rate of mortality representing up to 15% of deaths in the automobile collisions. About 4/5 of patients with aortic injuries die before intra-hospital care with a rate of up to 90% of death after 14 days of those who survive [1][2][3] .…”