Traumatic rupture thoracic aorta · ruptured aorta wasmissed in onepatient (case 2), andthe difficulties of diagnosing this condition, even during thoracotomy, are emphasized. The

Thorax (1969), 24, 25.

Traumatic rupture of the thoracic aortaG. KEEN, R. A. BRADBROOK, AND F. McGINN

From the United Bristol Hospitals

Seven patients who had traumatic ruptures of the thoracic aorta are reported. Four of thesedied within a few hours of admission, allowing no opportunity for diagnosis or treatment.However, three survived long enough for elective surgery to be undertaken. A diagnosis ofruptured aorta was missed in one patient (case 2), and the difficulties of diagnosing this condition,even during thoracotomy, are emphasized. The value of serial chest radiography and forwardaortography is discussed. Two of these patients underwent successful aortic repair, using leftatrio-femoral bypass.

This report describes our experience with thiscondition at one hospital over a five-year periodand includes those patients who died within a fewhours of admission and those who survived longenough for the diagnosis to be established and forattempted surgical repair to be undertaken. Ofseven patients, two ultimately recovered.

CASE REPORTS

CASE 1 A man aged 62 was admitted to BristolRoyal Infirmary on 27 July 1963. He was working onthe supporting chains of Clifton Suspension Bridgefrom which he fell 20 ft. (6 m.) to the roadway ofthe bridge, apparently falling on his outstretchedhands in a face-down position. He was admitted ina very shocked condition and despite attempts atresuscitation he died 90 minutes later. At necropsyhe had an almost complete circumferential tear of thethoracic aorta just above the diaphragm. Other in-juries included multiple fractures, among which werebilateral Colles' fractures.

CASE 2 A man aged 28 was admitted to BristolRoyal Infirmary on 4 December 1965 having beeninvolved in a motor vehicle accident. He had sus-tained concussion, a fractured pelvis, fractures of theleft ribs 2-10 and of the shaft of the left femur, and aruptured diaphragm with herniation of some abdomi-nal contents into the thorax (Fig. 1).

Operation A left postero-lateral thoracotomy throughthe eighth intercostal space was carried out. The leftpleural cavity contained stomach, omentum, trans-verse colon, and spleen, together with 200-300 ml. ofblood. There was bruising of the hilum of the lungbut no other abnormality was detected. The leftdiaphragm was torn from the chest wall radially tothe oesophageal hiatus. The abdominal viscera werereplaced and the diaphragm was repaired with two

rows of thread sutures. A Steinmann pin was insertedinto the left tibial tubercle for traction of the frac-tured femur. At the end of the operation the patient'sbreathing was inadequate and tracheostomy was per-formed to conduct positive pressure ventilation. Post-operatively he appeared well, although he was anuricand was therefore transferred to Ham Green Hospital,the regional dialysis centre, for treatment. Haemodia-lysis was undertaken on two occasions but on theninth post-operative day he died suddenly.

Necropsy findings The significant finding at necropsywas a complete circumferential tear of the aorta justbelow the origin of the left subclavian artery. Bloodhad been contained within a small sac composed ofadventitia which had ruptured shortly before death,with resulting haemorrhage into the mediastinum andinto the root of the neck in front of the vertebralcolumn.

Subsequent examination of chest radiographs takenat the time of admission to Bristol Royal Infirmaryand to Ham Green Hospital (the last being one daybefore death) showed the mediastinal shadow to beenlarged, and although none of these radiographswas truly antero-posterior, owing to the difficulty ofexamining this patient, the diagnosis could have beensuspected earlier, with the possibility of successfultreatment.

CASE 3 An 18-year-old girl was admitted on 9 July1965 to Bristol Royal Infirmary. She had been drivinga motor scooter with a pillion passenger (case 4) andhad collided head-on with a saloon car. On admissionshe was unconscious and barely breathing and died15 minutes later. Necropsy showed a complete cir-cumferential tear of the aorta just beyond the leftsubclavian artery. There was also a fractured lefttibia and fibula.

CASE 4 A young man aged 20 was admitted at thesame time as case 3, also unconscious, and he also

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G. Keen, R. A. Bradbrook, and F. McGinn

FIG. 1. Case 2. Radiograph at time of admission. Evidence of rupturedleft leaf of diaphragm was obvious but the mediastinal shadow wasregarded as normal.

died shortly after admission. Necropsy showed anaortic tear identical to that found in case 3. Therewas also a fractured shaft of the right femur andmultiple fractures of the pelvis.

CASE 5 A 40-year-old man was admitted to BristolRoyal Infirmary on 25 October 1966 following a roadtraffic accident. On examination he had surgicalemphysema of the right side of the chest and aninjury to the right femur. Chest radiographs, retro-spectively, showed the mediastinum to be widenedand there were multiple right rib fractures (Fig. 2).A radiograph of the right femur showed a supra-condylar fracture. The patient was transferred to theoperating theatre for suture of a lacerated scalp andinsertion of a Steinmann's pin through the right tibialtubercle. At the completion of this operation, cardiacarrest supervened but he was resuscitated by externalcardiac massage. Three hours later his conditiondeteriorated and a further chest radiograph showedthe left chest to be opaque. At this stage advicewas sought from the thoracic service and the patientwas removed to the operating theatre where imme-diate left thoracotomy was undertaken. However, assoon as the chest was opened it was obvious thatthe aorta had ruptured and death took place almost at

once. At necropsy the aorta was found to be com-pletely ruptured through all layers circumferentiallyat the level of the ligamentum arteriosum.

CASE 6 A 54-year-old man was admitted on 25October 1967 having been involved in a head-on colli-sion whilst in the front passenger seat of a small car. Hewas concussed and suffered a central dislocation ofthe right hip. A chest radiograph (Fig. 3) showed themediastinal shadow to be rather wide. This patienthad undergone thoracic surgery for the repair of ahiatus hernia 10 years previously and fortunatelythere was available a follow-up radiograph takenthree months previously. In comparison with the pre-sent radiograph the increase in size of the mediastinalshadow was obvious (Fig. 3). An aortogram (Fig. 4)showed an almost complete circumferential tear ofthe aorta just below the left subclavian artery.

Operation The patient was positioned for leftthoracotomy and the left femoral artery was exposed.The left chest was opened widely through the fourthinterspace. There were a few pleural adhesions result-ing from a previous hiatus hernia repair. The aorta,at and below the left sub-clavian artery, was the siteof a dense haematoma. Cannulation for left atrio-

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Traumatic rupture of the thoracic aorta

FIG. 2. Case 5. Chest radiograph at timeof admission (a), with rapid progress toleft haemothorax (b).

(a)

(b)

femoral bypass was undertaken before further dissec-tion. The aorta was mobilized proximal to the leftsubclavian artery where it was clamped and the leftsubclavian artery was also clamped. The aorta wasmobilized well below the haematoma and clamped,and the patient was then put on left atrio-femoralbypass using a cannula from the left atrium to a

reservoir and thence to the pump and left femoralartery. It was found that a flow of 2-5 1. per minutethrough the femoral artery allowed good perfusionand gave a right radial arterial pressure of 80 mm.Hg. The patient passed urine during perfusion, indi-cating satisfactory renal perfusion. Heparin, 1 mg./kg.body weight, had been given just prior to perfusion.

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(a)

FIG. 3. Case 6. Comparison between radio-graph (a) (23.5.67) and (b) (25.10.67) showsan obvious increase in the size of the aorticknuckle.

(b)

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FIG. 4. Case 6. Forward aortogram demonstrating tear ofaorta distal to origin of left subclavian artery.

The aortic haematoma was explored, showing analmost complete rupture of the media and a completerupture of the intima 1 cm. below the left subclavianartery. This area was excised and replaced with aI in. length of woven Dacron, using continuous suturesof 4/0 silk. Following this, when the clamps werereleased, small bleeding points at the anastomosiswere controlled with extra sutures. Heparin wasneutralized with protamine sulphate, 1 mg./kg. bodyweight. The patient was taken off bypass and thechest was closed in layers with one pleural drain.The left femoral artery was repaired in continuity.

Post-operatively the patient made a satisfactoryrecovery and at the time of discharge his residualsymptom was diplopia when looking to the extremeright, which was thought to be due to an associatedorbital injury.

CASE 7 A 60-year-old man was admitted on 8November 1967 having been knocked down by a carwhilst road sweeping. His injuries included a lacera-tion of the scalp, supracondylar fracture of the leftfemur, and a ruptured diaphragm.

Operation A left postero-lateral thoracotomy wasdone through the seventh intercostal space. Thestomach and spleen had herniated through a rent inthe diaphragm which extended radially from the chestwall almost to the oesophageal hiatus. The spleenwas torn and bleeding. Splenectomy was done; the

stomach was reduced into the abdomen and thediaphragm was repaired with two rows of continuoussilk. In view of our previous recent experience, theaorta was examined from the subclavian artery dis-tally, but apart from tortuosity no evidence of injurywas present. Skin traction was applied to the lefttibia and primary grafting of a skin defect over thevault of the skull was carried out. The patient madea good recovery from this operation. However, fourdays post-operatively a chest radiograph showedwidening of the mediastinal shadow and an aorto-gram taken on the same day showed an obvious tearwith dissection just distal to the left subclavian artery.Operation was undertaken three hours later.

Operation The left femoral artery was exposed anda left thoracotomy was undertaken through the fourthinterspace. The left atrium was cannulated and a leftatrio-femoral bypass was held in readiness. The lungwas then reflected forward and the aorta wasexamined. It appeared to be of normal size; butthere was a bruise of the whole circumference about12 cm. below the left subclavian artery. When theaorta was palpated more carefully, a haematoma wasfelt at its posterior aspect. A left atrio-femoral bypasswas managed as in case 6. A clamp was applied tothe arch of the aorta just proximal to the left sub-clavian artery. The left subclavian artery wasclamped, as was the distal aorta. The aorta was tran-sected at the level of the left subclavian artery. Onecentimetre proximal to this there was a completecircumferential tear of the intima and media, extend-ing to the lower aortic segment which appeared astwo concentric tubes separated by fresh clot. The tearhad also extended proximally along the aortic archbeyond the aortic clamp. The intima and media weresutured back to the adventitia using numerous 4/0silk sutures. The distally transected aorta was firstrepaired with a running suture re-uniting the dissectedmedia to the adventitia, and the aorta was then re-paired end-to-end, using continuous 4/0 silk. TIheaorta was very atherosclerotic but on release of theclamps good haemostasis had been secured. The chestwas closed in layers with one pleural drain, and theleft femoral artery was repaired in continuiity.The patient made a slow but satisfactory recovery

from his injuries.

DISCUSSION

INCIDENCE Traumatic rupture of the aorta is notrare and there are numerous reports of smallgroups of patients. Strassmann (1947) reported7,000 necropsies on patients who were either deadon admission or died on the day of admission tohospital. In 69 of these (1%) death was due totraumatic rupture of the aorta. National statisticsrelating to the frequency of this condition arenot available in the United Kingdom. However,Brown (1967, personal communication) describes

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19 patients in whom this injury was identified atcoroner's necropsies conducted by him in Bristolover the previous five years. These, together withthe patients discussed in this paper, show an inci-dence of 26 such cases occurring in a populationof about half a million in five years. Since allpatients suffering a traumatic death are subject tonecropsy, it is likely that these figures are sub-stantially correct.

PATHOLOGY Rupture of the aorta involves theintima and media and is usually a circumferentialtear at or just below the origin of the left sub-clavian artery, although avulsion of the innomi-nate artery occurs less frequently. The haematomais usually contained by the thick adventitia,although the ruptured ends of the media may beseveral centimetres apart. This false aneurysmmay rupture within minutes, hours or days, orproceed to the formation of a chronic aneurysmwhich may remain unsuspected for many years.Rice and Wittstruck (1951) discuss the mecha-nism of rupture with deceleration injuries andobserve that, whenever one part of the body isdecelerated at a rate which differs from that ofanother part, the connexion between these twoparts is under stress, which is proportional to therate of deceleration. Violent deceleration, such asaccompanies head-on automobile collisions, air-craft crashes or falls from a height will producesuch a state of affairs, the descending thoracicaorta continuing a forward movement, whereasthe aortic arch is retained by the great vessels.This probably explains the frequency of tears atthe level of the ligamentum arteriosum or at theorigin of the innominate artery. The aorta neednot be diseased (as it was in case 7) for themajority of recorded cases occurred in young andpreviously healthy adults. Jahnke, Fisher, andJones (1964) recorded six patients successfullytreated at the Walter Reed General Hospital,Washington by surgical repair, using left atrio-femoral bypass or cardiopulmonary bypass. Thesepatients probably underwent a process of naturalselection as they were operated on at intervals of22 hours, 4, 7, 6, 14, and 15 days following injury,usually having been transferred great distances-in some cases from Europe-for surgery. Spencer,Guerin, Blake, and Bahnson (1961) reported sevensuch patients, one of whom survived surgery. Theyalso reported eight cases of late traumatic aneu-rysm at the level of the ligamentum arteriosum,seven of whom survived resection of the aneurysm.One of this group had his operation 37 yearsfollowing the presumptive injury (having been

kicked by a calf). This may imply that once apatient who has developed a false aneurysm hassurvived for more than a few years, the ultimateprognosis may be relatively good. Both theseauthors stressed the value of forward aortographyto locate the site of the aortic lesion. Eiseman andRainer (1958), Alley, Van Mierop, Li, Kausel, andStranahan (1961), Bromley, Hobbs, and Robinson(1965), and Roberts and Lord (1967) also reportedpatients who survived surgical repair of traumaticrupture of the aorta. Most patients in these series,and our own patients, were the victims of severedeceleration or acceleration injuries, prominentamong which were head-on automobile collisions,the patient usually having occupied the frontpassenger seat. Associated injuries were frequentand included ruptured diaphragm, rupturedspleen, fractured femur and broken ribs, occurringseparately or together. In the present series, frac-tured femur, tibia or dislocated hip occurred insix, ruptured diaphragm in two, and rupturedspleen in one. Head injuries were almost invari-able. It was therefore not surprising that theseassociated injuries usually obscured the aortic dis-ruption; many patients died suddenly and un-expectedly in hospital days or weeks followingsuccessful surgical treatment for other injuries(case 2). This injury is more likely to be diagnosedif it is suspected, and serial radiology of the chestwill often show a progressively widening medias-tinum. Suspicion is best confirmed by forwardaortography, achieved by advancing a catheter(introduced by the Seldinger technique into thefemoral artery) into the ascending aorta, at whichpoint the injection should be made. This seemsto be the only certain way of demonstrating abreak at any point in the aortic arch. This investi-gation was helpful in our two surgically treatedcases and there is little doubt that in case 7, inwhom the aorta appeared normal at operation,only incontrovertible aortographic evidence ofaortic disruption prevented the operation beingabandoned as a false alarm. Others have com-mented on the frequent benign appearance of theaorta at operation. Eiseman and Rainer (1958)reported such a patient who, despite a clinicaldiagnosis of traumatic rupture of the aorta, wasfound to have an apparently normal aorta atexploratory thoracotomy. Aortotomy was there-fore not carried out. However, this patientdeveloped an aneurysm, clearly seen on chestradiographs three weeks later. At a further opera-tion the aortic wall was found to be completelytransected just below the left subclavian artery,with a 6 cm. separation of aortic ends opening

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into the aneurysmal sac. In the patient who diedof aortic rupture 9 days after thoracotomy torepair the diaphragm (case 2), the aorta appearednormal at operation as it also did in the firstoperation on the patient (case 7). The usual courseis for traumatic false aneurysm to rupture in amatter of hours, days or weeks following injury.Since there is no way to determine which patientswill survive to form a chronic aneurysm, anattempt at surgical repair must follow diagnosis assoon as possible and certainly in many of thepatients in whom surgical repair is undertaken asuccessful outcome can be expected.

Left atrio-femoral bypass (Cooley, DeBakey,and Morris, 1957; Gerbode, Braimbridge, Os-born, Hood, and French, 1957) allows satisfac--tory and safe operating conditions, preventingproximal hypertension and left ventricular strainduring aortic cross clamping and furthermoreensures adequate renal and spinal cord perfusion.Heparinization and its reversal by protamineposes no undue bleeding problems at the aorticrepair. However, should intra-abdominal bleedinghave been overlooked or intra-cerebral bleedingbe taking place, heparinization might significantlyaffect this.

We are grateful to Dr. Rhys-Davies for performingaortography on patients 6 and 7, and to Miss A.Pakington who managed the left atrio-ventricularbypass. We also thank Dr. G. Burton and Dr. P.Baskett who anaesthetized patients 6 and 7 respec-tively, and Professor T. Hewer and Dr. N. Brownfor access to necropsy reports on the fatal cases.

REFERENCES

Alley, R. D., Van Mierop, L. H. S., Li, E. Y., Kausel, H. W., andStranahan, A. (1961). Traumatic aortic aneurysm: graftlessexcision, anastomosis. Arch. Surg., 83, 300.

Bromley, L. L., Hobbs, J. T., and Robinson, R. E. (1965). Early repairof traumatic rupture of the thoracic aorta. Brit. med. J., 2, 17.

Cooley, D. A., DeBakey, M. E. and Morris, G. C. (1957). Controlledextracorporeal circulation in surgical treatment ofaortic aneurysm.Ann. Surg., 146, 473.

Gerbode, F., Braimbridge, M., Osborn, J. J., Hood, M., and French, S.(1957). Traumatic thoracic aneurysms: treatment by resectionand grafting with the use ofan extracorporeal bypass. Surgery, 42,975.

Eiseman, B., and Rainer, W. G. (1958). Clinical management of post-traumatic rupture of the thoracic aorta. J. thorac. cardiovasc.Surg., 35, 347.

Jahnke, E. J., Fisher, G. W., and Jones, R. C. (1964). Acute traumaticrupture of the thoracic aorta. Report of six consecutive cases ofsuccessful early repair. Ibid., 48, 63.

Rice, W. G., and Wittstruck, K. P. (1951). Acute hypertension anddelayed traumatic rupture of the aorta. J. Amer. med. Ass., 147,915.

Roberts, J. C., and Lord, P. W. (1967). Ruptured thoracic aorta.Anaesthesia, 22, 415.

Spencer, F. C., Guerin, P. F., Blake, H. A., and Bahnson, H. T. (1961).A report of 15 patients with traumatic rupture of the thoracicaorta. J. thorac. cardiovasc. Surg. 41, 1.

Strassmann, G. (1947). Traumatic rupture ofthe aorta. Amer. Heart J.,33, 508.

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Traumatic rupture thoracic aorta · ruptured aorta wasmissed in onepatient (case 2), andthe difficulties of diagnosing this condition, even during thoracotomy, are emphasized. The