In deceleration accident, which of the following fixed pa of aoa is not ruptured
Ans. b. Behind the esophagus "The majority of blunt injuries to the thoracic aoa occur at aoic isthmus just distal to the left subclan aery. Other locations include the transverse arch, proximal ascending aoa, and descending aoa just proximal to the diaphragm."- Sevitt S. The mechanisms of traumatic rupture of the thoracic aoa. Br J Surg 1977; 64; 166 "Tethering of aoa by the ligamentum aeriosum is believed to account for the high frequency of aoic injury in the isthmus region." Traumatic Aoic Rupture Traumatic aoic rupture is a cause of sudden death after an automobile collision or fall from a great heightdeg. Vessel is relatively fixed distal to the ligamentum aeriosum, just distal to the origin of the left subclan aerydeg. Causes: Trauma to the chest, Rapid deceleration injury Clinical Presentation: Traumatic aoic rupture is lethal in 75-90% of patients and only 15-20% arrive at the hospital alivedeg. Approx. 90% of those who arrive alive at the hospital have an injury in the region of the aoic isthmus >Injuries to the ascending aoae. Usually associated with other injuries like solid organ. Diagnosis: X-ray chest: Widened mediastinume Aoography: Gold standard for diagnosis Contrast enhanced CT, Trans-esophageal Echocardiography (TEE) is useful in making diagnosis. Traumatic Aoic Rupture Clinical Features History of high-speed decelerationQ injury Flail chestQ Fractured sternumQ SVC syndromeQ Multiple or 1st or 2nd rib fracturesQ Upper extremity hypeension or pulse deficitsQ Hematoma in the carotid sheathsQ Interscapular bruitsQ Hoarseness with normal larynxQ Radiographic Features Widening of mediastinumdeg (70%)Q Esophageal detion to the rightQ Tracheal detion to rightQ Leftdeg apical cap (65%)Q Downward displacement of left main stem bronchusQ Right paratracheal stripe thickeningQ Detion of NG tube to rightQ Left hemothoraxQ Displaced left paraspinal stripeQ Displaced right paraspinal stripeQ Treatment: Control of systolic BP to less than 100 mm HgQ Endovascular intra-aoic stentingeQ Direct repair or excision and grafting using a Dacron graftQ
At the level of aoic valve
Behind the esophagus
Where it pierces the crura of diaphragm
At ligamentum aeriosum