Thoracic aortic injury

Most traumatic aortic injuries are the result of penetrating causes, whereas blunt aortic injury is less common. The initial treatment is determined by the patient's condition. Diagnostic studies include catheter arteriography, computed tomography, and transesophageal echo cardiography. This article summarizes the initial evaluation and management of patients with an aortic injury and describes the various treatment options such as delayed selective management, endovascular solutions, and surgical repair.     

Traumatic aortic injury

Optimal timing of surgical repair for traumatic aortic injury (TAI) is still controversial. We have experienced 3 cases of TAI. The 1st one suffered from severe multisystem trauma in addition to TAI, so we performed graft replacement of the proximal descending aorta electively 31 days after the injury. The 2nd one had massive pleural effusion on admission and we performed urgent operation. They recovered uneventfully. The last one died of aortic re-rupture during anesthetic induction despite attempting emergent operation. In patients with serious multisystem trauma besides TAI, surgical repair can be delayed as long as there are no signs of on-going rupture and/or bleeding, however close observation, serial computed tomography( CT) check-ups and strict control of blood pressure are needed.     

Blunt thoracic aortic injury

Blunt thoracic aortic injury (BAI) is a rare but often fatal injury that occurs with severe polytrauma. Immediate diagnosis and treatment of BAI are essential for a successful outcome. We reviewed our experience with 20 patients with BAI treated at a Level I trauma center between 1995 and 2006. The mean Injury Severity Score was 38 +/- 14 and 14 patients had an abnormal Glasgow Coma Score; associated injuries included abdomen in 13 patients, extremity in 12, and head in six. Chest x-ray (CXR) findings were suggestive of aortic injury in 15 patients, equivocal in three, and showed no evidence of aortic injury in two. Diagnosis was made by CT angiography (CTA) in 17 patients, transesophageal echocardiography (TEE) in two, and formal angiography in one. Sixteen patients underwent operative repair of BAI. Of these, eight also underwent laparotomy, six had operative repair of extremity fractures, and three had pelvic embolization. Five patients died, three of whom were treated nonoperatively, and length of hospitalization in survivors was 32 +/- 20 days. BAI is rare and often associated with multiple life-threatening injuries complicating diagnosis and treatment. Our data support the aggressive use of CTA even when classic CXR findings are not present. When CT must be delayed for abdominal exploration, intraoperative TEE is useful.     

Imaging of thoracic aortic injury

Isthmic aortic rupture or disruption should be systematically sought when there is high kinetic energy trauma to the thorax. This condition is extremely serious and life threatening. It needs to be diagnosed rapidly but diagnostic pitfalls must be avoided. CT angiography is the standard examination. The main CT signs of rupture or disruption of the thoracic aorta are periaortic hematoma, intimal flap, pseudo-aneurysm and contrast agent extravasation. There are three types of lesion: intimal, subadventitial or pseudo-aneurysmal, and complete rupture with lesion of the three tunicae, and it is important to grade them for better therapeutic management. The main diagnostic pitfalls of the CT scan are the presence of a ductus diverticulum and post-isthmic fusiform dilatation. Associated lesions must not be overlooked. The most common are ruptures of the aortic root and the thoracic aorta in the diaphragmatic hiatus.     

Seat-belt injuries of the spine in young children.

Seat-belt fractures of the lumbar spine in adolescents and adults are well recognised but there are few reports of these injuries in young children. We reviewed all seat-belt injuries in skeletally immature patients (Risser 0), seen at a tertiary referral centre between 1974 and 1991. There were ten cases, eight girls and two boys, with an average age of 7.5 years (3 to 13). Four distinct patterns of injury were observed, most commonly at the L2 to L4 level. Paraplegia, which is thought to be uncommon, occurred in three of our ten cases. Four children had intra-abdominal injuries requiring laparotomy. There was a delay in diagnosis either of the spinal or of the intra-abdominal injury in five cases, although all had contusion of the abdominal wall, the 'seat-belt sign'. Treatment of the fractures was conservative, by bed rest and then hyperextension casts. The incidence of this potentially devastating injury can be reduced by the optimal use of restraints, but there is often a delay in diagnosis. Our classification system may aid in the early detection and evaluation of this injury.     

Nonoperative management of traumatic aortic injury

BACKGROUND: The standard management for patients with blunt aortic injury is surgery; however, a small number of patients have been medically managed. The outcome of these nonoperatively managed patients is unknown. METHODS: Seven patients diagnosed as blunt aortic injury were managed without aortic surgery between January 1993 and April 2002, and their outcomes were retrospectively investigated. RESULTS: There were three men and four women, with a mean age of 48.7+/-22.7 years and Injury Severity Score of 37.7+/-16.9. The reason for nonoperative management was refusal of surgery (2), do-not-resuscitate order (1), diffuse brain injury (2), small intimal tear (1), and technical difficulty (1). Two patients died resulting from associated injuries. Five patients are alive, and in three patients complete resolution of aortic injury was observed. CONCLUSIONS: In selected patients with multiple associated injuries or severe comorbidity, nonoperative management after blunt aortic injury can be a treatment of choice.     

Combined blunt aortic and bronchial injury

We report the case of a 29-year-old man with left blunt chest trauma resulting in an intimal tear of the proximal descending aorta, for which he underwent successful thoracic endovascular graft stenting. He subsequently developed progressive left lung collapse, and bronchoscopy revealed left bronchial disruption. A left thoracotomy with end-to-end anastomosis of the left bronchus was performed successfully. The literature from 6 other similar cases of concomitant aortic and bronchial injuries was reviewed.     

Multiple subfailures characterize blunt aortic injury

BACKGROUND: Blunt aortic injuries result from rapid deceleration of the thorax as may occur during automotive impacts and falls from extreme heights. Pathological findings can range from failure of specific vessel layers to immediate vessel wall rupture. The purpose of this investigation was to determine the sequence of local structural events that may lead to aortic wall disruption. METHODS: Fourteen porcine aorta specimens were opened to expose the intima and longitudinally distracted until rupture. Longitudinal mechanics were quantified and subfailures were identified. Histology was used to examine internal layer subfailure. RESULTS: Videography demonstrated that subfailures propagated into complete vessel wall rupture. Subfailures occurred before complete vessel rupture in 93% of specimens. Intimal and medial subfailures were present at 74% of the stress and 82% of the strain to rupture. Multiple subfailures were evident in 79% of specimens. CONCLUSION: Present results supported the clinical theory that nonimmediate death as a result of blunt aortic injury is commonly caused by propagation of lesser lesions, initiating on the intimal layer, into complete vessel rupture including the adventitial layer. This finding, along with histologic evidence of subfailure pathological findings, confirms the presence of an acute window during which recognition and initiation of permissive hypotension may be lifesaving.     

Myocardial injury in major aortic surgery

PURPOSE: The purpose of this study was to examine the effects of major aortic surgery and its associated oxidative stress and injury on the myocardium. METHODS: Plasma from 27 patients who underwent thoracoabdominal aortic aneurysm (TAAA) repair and 17 patients who underwent infrarenal aortic aneurysm (AAA) repair was collected at incision, aortic crossclamping, and reperfusion and 1, 8, and 24 hours thereafter. Samples were assayed for the myocardial specific protein troponin-T, total antioxidant status, and lipid hydroperoxides. RESULTS: Ten patients experienced cardiac dysfunction in the first 24 hours after surgery (eight patients in the TAAA group and two patients in the AAA group). Immediately after reperfusion, total antioxidant status levels dropped in all patients with TAAA and with AAA; this was more marked in patients with TAAA, leading to a significant difference between the two groups at this time point and for up to 1 hour thereafter (P <.01). Patients with TAAA showed a sharp rise in lipid hydroperoxide levels immediately after reperfusion, and levels were significantly higher than in patients with AAA (P =.0007). In patients with AAA, no significant change in troponin-T was observed throughout the study period; whereas in patients with TAAA, levels were significantly elevated at 8 and 24 hours after reperfusion (P <.01). Troponin-T levels significantly correlated with total antioxidant status (r = -0.5) and lipid hydroperoxides (r = 0.78) but not with systolic blood pressure. CONCLUSION: Supracoeliac aortic crossclamping is associated with a significant release of the myocardial injury marker troponin-T. This seems to correlate with the severity of oxidative rather than hemodynamic stresses. Ameliorating oxidative injury during TAAA surgery may therefore have a cardioprotective effect.     

Endovascular repair for ruptured thoracic aortic aneurysm and traumatic aortic injury

In contrast to high mortality of open surgery for thoracic aortic catastrophes including ruptured thoracic aortic aneurysm (RTAA) and traumatic aortic injury (TAI), excellent short-term outcomes of thoracic endovascular aortic repair (TEVAR) have recently been reported. We report our single-center experiences with TEVAR for aortic catastrophes. Thirteen patients with thoracic aortic catastrophes (RTAA in 7 patients, TAI in 6 patients) have received TEVAR from February 2004 to June 2010. In cases of RTAA, 5 descending aortic aneurysm ruptures and 2 aortic arch aneurysm ruptures were included. In patients with arch aneurysm ruptures, fenestrated stent grafting (SG) and SG combined with arch debranching were performed. In all cases of TAI, aortic injuries occurred near the isthmus and 5 patients received fenestrated SG. The initial success rate was 100% and there was no perioperative death. Mean duration of observation was 24 months, which revealed 4 late deaths. The causes of late death were liver failure, cerebral contusion, senility and unknown. A patient with RTAA experienced a type III endoleak as an aorta-related event 24 months after operation. There was no enlargement of aneurysm in any patient. TEVAR for aortic catastrophes seems to be performed safely with acceptable outcomes. Although morphological incompatibility, unstable preoperative haemodynamics and longer time for preparation may become impediments to perform TEVAR, we believe that TEVAR should be the 1st choice for life-threatening aortic catastrophes. However, a careful follow-up is necessary because TEVAR has several unique late complications.     

Natural history of minimal aortic injury following blunt thoracic aortic trauma

Background

Endovascular repair of blunt traumatic thoracic aortic injuries (BTAI) is common at most trauma centres, with excellent results. However, little is known regarding which injuries do not require intervention. We reviewed the natural history of untreated patients with minimal aortic injury (MAI) at our centre.

Methods

We conducted a retrospective database review to identify all patients with a BTAI between October 2008 and March 2010. The cohort comprised patients initially untreated because of the lesser degree of injury of an MAI. We reviewed initial and follow-up computed tomography (CT) scans and clinical information.

Results

We identified 69 patients with a BTAI during the study period; 10 were initially untreated and were included in this study. Degree of injury included intimal flaps (n = 7, 70%), pseudoaneurysms with minimal hematoma (n = 2, 20%) and circumferential intimal tear (n = 1, 10%). Six (60%) patients were male, and the median age was 40 years. Duration of clinical follow-up ranged from 1 month to 6 years (median 2 mo) after discharge, whereas CT radiologic follow-up ranged from 1 week to 6 years (median 6 wk). Seven (70%) patients had complete resolution or stabilization of their MAI, 1 (10%) with circumferential intimal tear showed extension of the injury at 8 weeks postinjury and underwent successful repair, and 2 (20%) were lost to follow-up.

Conclusion

There appears to be a subset of patients with BTAI who require no surgical intervention. This includes those with limited intimal flaps, which often resolve. Radiologic surveillance is mandatory to ensure MAI resolution and identify any progression that might prompt repair.     

Management of blunt thoracic aortic injury.

Blunt traumatic aortic transection (TAT) is an uncommon injury in clinical practice that is associated with a high morbidity and mortality. The approach to patients with such an injury is controversial with specific regard to the most effective diagnostic tools, timing of surgical intervention and mechanisms of spinal cord protection. Chest X-ray with widening of the mediastinum is unreliable as a diagnostic tool. Contrast enhanced helical CT Scan has replaced the traditional angiography as the screening diagnostic tool of choice Emergency thoracotomy and repair should be reserved for the few patients with isolated TAT without any major concomitant injuries. Delayed management approach with aggressive blood pressure control and serial radiological monitoring is a safe and recommended option for those with severe concomitant injuries or other medical co-morbidity that puts surgery at high risk. Active augmentation of the distal perfusion pressure during cross clamp offers the best protection against development of paraplegia during open surgical repair. Endovascular stenting offers a minimally invasive method of treatment but the long-term durability of the endovascular stent is still unknown. We feel that the greater feasibility of the endovascular repair in the acute phase of the thoracic injury is an advantage over the open surgery and should be the treatment of choice in patients with severe concomitant injuries.     

Spinal cord injury following aortic arch replacement

Surgery Today - Postoperative spinal cord injury is a devastating complication after aortic arch replacement. The purpose of this study was to determine the predictors of this complication. A group...