Ann Thorac Surg 2006;82:1095-1097
© 2006 The Society of Thoracic Surgeons
Case report
Traumatic Innominate Artery Disruption and Aortic Valve Rupture
Michael W.A. Chu, MD, MEd,
Mary Lee Myers, MD*
Division of Cardiac Surgery, Department of Surgery, University of Western Ontario, London, Ontario, Canada
Accepted for publication January 10, 2006.
* Address correspondence to Dr Myers, Division of Cardiac Surgery, London Health Sciences Centre, Room B6-114, 339 Windermere Rd, London, Ontario, N6A 5A5 Canada (Email: ml.myers{at}lhsc.on.ca).
 |
Abstract
|
|---|
Rapid deceleration injury causing blunt thoracic trauma can result in injury to the thoracic aorta. Rupture of the aortic isthmus is the most common presentation; however, injury can occur more proximally in the arch vessels or the aortic root. We present an unusual case of simultaneous innominate artery disruption with aortic valve rupture after a motor vehicle accident, and we discuss issues surrounding the diagnosis and operative management of this rare, but life-threatening condition.
|
Introduction
|
|---|
Blunt thoracic aortic trauma occurs most commonly after motor vehicle accidents and carries a very high mortality risk. Most patients have major associated injuries and only a small percentage of patients survive to hospitalization with approximately 90% lethality in the field. Acute transection of the proximal descending thoracic aorta occurs most commonly, but it is important to also screen for injury to the aortic root, the great vessels, and the heart. Diagnosis can be made by computed tomography or transesophageal echocardiography, or both. Urgent intervention is necessary to prevent hemodynamic collapse; however, consideration should be given to all major injuries, addressing each in order of pressing magnitude.
A 19-year-old man who was driving was involved in a high-speed motor vehicle accident in which his car veered off an embankment and landed partially submerged in freezing water. He was wearing his seat belt. After 30 minutes of extrication, he was intubated and transported to our tertiary center where the initial assessment revealed a sinus tachycardia, blood pressure of 184/68, a temperature of 34.4°C, and a Glasgow coma score of 8T. Chest roentgenogram demonstrated bilateral pulmonary contusions and a left hydropneumothorax. A secondary survey identified a sternal fracture, no jugular venous distention, and an open left femur fracture. Electrocardiography revealed sinus tachycardia with no ST-segment elevation abnormalities and a troponin I level that was 0.26 µg/mL. His past medical history was unremarkable. A computed tomographic chest scan identified an innominate artery injury with contrast extravasation (Fig 1), bilateral pulmonary contusions, a small left pleural effusion, and a grade I–II splenic laceration. Primary resuscitation consisted of a left chest tube thoracostomy, warmed intravenous crystalloid fluids, and external rewarming. After the patient was stabilized in the intensive care unit, he was taken to the operating room to explore the innominate artery injury.
View larger version (82K):
[in this window]
[in a new window]
|
Fig 1. Spiral computed tomographic scan demonstrating extraluminal contrast in the mediastinum, posterior to the origin of the innominate artery (arrow).
|
|
After induction of general anesthesia, transesophageal echocardiography revealed severe aortic insufficiency with an abnormal appearing ascending aorta. A median sternotomy incision was utilized with a right supraclavicular extension for adequate exposure of the innominate artery and its bifurcation. There was a hematoma involving the ascending aorta and an easily palpable thrill at the aortic root. These findings raised concerns about a possible retrograde aortic dissection and accordingly cardiopulmonary bypass was initiated through the left common femoral artery and the right atrium. The innominate artery was isolated and a 9-French balloon-tipped cannula was placed into the distal segment for antegrade cerebral perfusion. The aortic cross clamp was applied between the innominate artery and the left common carotid artery, and a separate clamp was placed on the distal innominate artery to isolate the innominate arterial injury. Cardiac arrest was achieved with retrograde cold blood cardioplegia, and antegrade cerebral perfusion was maintained at a flow rate of 200 mL/min. An oblique aortotomy revealed a nondissected aorta, a normal tricuspid aortic valve, but a ruptured noncoronary cusp. The proximal innominate artery was found to be completely disrupted from the aortic arch apart from the adventitial layer with a posterior directed false aneurysm. A 10-mm Dacron (Vascutek, Inchinnan, Scotland) graft was used to anastomose the innominate artery to the aorta. An attempt was made to repair the ruptured aortic valve cusp with a single running 5-0 Prolene (Ethicon, Somerville, NJ) suture, reattaching the ruptured edge of the leaflet to the annulus with a single plication stitch at the commissure adjacent to the left coronary cusp. After weaning from cardiopulmonary bypass, transesophageal echocardiography showed a persistent central jet consistent with moderate aortic insufficiency. Accordingly, the heart was rearrested and the aortic valve was replaced with a 21-mm bi-leaflet mechanical valve. The patient was easily weaned from cardiopulmonary bypass with a low-dose norepinephrine infusion. Postoperatively, all vasoactive medications were quickly weaned, but he remained intubated until definitive management of his orthopedic injuries was completed the following day. Repeat abdominal computed tomography demonstrated that his splenic injury was stable and unchanged. The remainder of his hospitalization was uneventful. He was discharged home on postoperative day 20. Follow-up echocardiography demonstrated normal left ventricular and prosthetic valve function with a residual gradient of 11 mm Hg.
|
Comment
|
|---|
Blunt thoracic aortic trauma is commonly caused by a sudden deceleration injury, usually occurring after a motor vehicle accident or fall from a great height. The isthmus is the most common location for this injury [1, 2]; however, the aortic root, arch, and origins of the brachiocephalic vessels can also be involved [3–5]. The mechanism of injury has been described as sudden anteroposterior mediastinal compression between the sternum and the vertebrae with acute cervical and aortic arch hyperextension that can result in avulsion of the origin of the innominate artery [3–5]. In our patient, the anteroposterior compression likely occurred as the aortic valve closed with the resultant force compressing the column of blood within the ascending aorta toward the largest sinus of Valsalva, resulting in rupture of the noncoronary cusp and acute aortic insufficiency [6]. The simultaneous presentation of these two injuries has not been previously described.
A high index of suspicion is required to make the diagnosis of blunt aortic injury. Our patient did not have the typical seat-belt sign or widened mediastinum on chest roentgenogram [1, 2]. Nonetheless, he did present with a sternal fracture and left hydropneumothorax that warranted further investigation with a contrast enhanced computed tomographic scan. Transesophageal echocardiography established the diagnosis of aortic insufficiency and should be used routinely in all patients with blunt innominate artery injury to evaluate the integrity of the aortic valve and to aid in the assessment of the ascending and descending aorta.
Although innominate artery injuries may be repaired without the use of CPB [3–5], it was necessary in this case to institute CPB with cardioplegic arrest to evaluate the ascending aorta and aortic valve. The use of CPB also permitted continuous antegrade cerebral perfusion while the innominate artery was repaired with an interposition graft. It was believed that an attempt to repair the valve was warranted, as the valve tissue initially appeared to be of reasonable quality and the commissures were essentially intact. However, others have concluded that aortic valve replacement provides a reliable, predictable long-term outcome compared with repair in the setting of traumatic injury [6, 7].
Simultaneous blunt traumatic innominate artery disruption and aortic valve cusp rupture is exceedingly rare and requires urgent operative intervention. Diagnosis can be made with contrast enhanced computed tomography and transesophageal echocardiography. When the patient is hemodynamically stable, operative repair can be delayed long enough to assess, stabilize, and appropriately prioritize all injuries.
|
Acknowledgments
|
|---|
Dr Chu received financial support from the William T. MacEachern Research Fellowship.
|
References
|
|---|
- Sturm JT, McGee MB, Luxenberg MG. An analysis of risk factors for death at the scene following traumatic aortic rupture J Trauma 1988;28:1578-1580.[Medline]
- Fabian TC, Richardson JD, Croce MA, Smith JS, Rodman Jr G, Kearney PA. Prospective study of blunt aortic injurymulticenter trial of the American Association for the surgery of trauma. J Trauma 1996;42:374-383.
- Karmy-Jones R, DuBose R, King S. Traumatic rupture of the innominate artery Eur J Cardiothorac Surg 2003;23(5):782-787.[Abstract/Free Full Text]
- Harris K, Youngson GG, McKenzie FN. Traumatic avulsion of the innominate artery J R Coll Surg Edinb 1981;26(1):39-41.[Medline]
- Stover S, Holtzman RB, Lottenberg L, Bass TL. Blunt innominate artery injury Am Surg 2001;67(8):757-759.[Medline]
- Devineni R, McKenzie FN. Avulsion of a normal aortic valve cusp due to blunt chest injury J Trauma 1984;24:910-912.[Medline]
- Girardi L, Isom OW. Repair of traumatic aortic valve disruption and descending aortic transection Ann Thorac Surg 2000;69:1251-1253.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
P. Kaul, R. George, R. Paniagua, A. Petsa, and S. Congiu
Innominate truncal dissection and rupture into right pleural cavity following acute type A dissection of the aorta with right coronary ostial avulsion and inferior STEMI
Perfusion,
September 1, 2011;
26(5):
435 - 440.
[Abstract]
[PDF]
|
|
|
Top
Abstract
Introduction
