Morphology and Risk Factors for Blunt Aortic Trauma in Car Accidents - An Autopsy Study

Authors: Ticijana Prijon, Branko Ermenc

Abstract:

Background: Blunt aortic trauma (BAT) includes various morphological changes that occur during deceleration, acceleration and/or body compression in traffic accidents. The various forms of BAT, from limited laceration of the intima to complete transection of the aorta, depends on the force acting on the vessel wall and the tolerance of the aorta to injury. The force depends on the change in velocity, the dynamics of the accident and of the seating position in the car. Tolerance to aortic injury depends on the anatomy, histological structure and pathomorphological alterations due to aging or disease of the aortic wall. An overview of the literature and medical documentation reveals that different terms are used to describe certain forms of BAT, which can lead to misinterpretation of findings or diagnoses. We therefore, propose a classification that would enable uniform systematic screening of all forms of BAT. We have classified BAT into three morphologycal types: TYPE I (intramural), TYPE II (transmural) and TYPE III (multiple) aortic ruptures with appropriate subtypes. Methods: All car accident casualties examined at the Institute of Forensic Medicine from 2001 to 2009 were included in this retrospective study. Autopsy reports were used to determine the occurrence of each morphological type of BAT in deceased drivers, front seat passengers and other passengers in cars and to define the morphology of BAT in relation to the accident dynamics and the age of the fatalities. Results: A total of 391 fatalities in car accidents were included in the study. TYPE I, TYPE II and TYPE III BAT were observed in 10,9%, 55,6% and 33,5%, respectively. The incidence of BAT in drivers, front seat and other passengers was 36,7%, 43,1% and 28,6%, respectively. In frontal collisions, the incidence of BAT was 32,7%, in lateral collisions 54,2%, and in other traffic accidents 29,3%. The average age of fatalities with BAT was 42,8 years and of those without BAT 39,1 years. Conclusion: Identification and early recognition of the risk factors of BAT following a traffic accident is crucial for successful treatment of patients with BAT. Front seat passengers over 50 years of age who have been injured in a lateral collision are the most at risk of BAT.

Keywords: Aorta, blunt trauma, car accidents, morphology, risk factors.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1094353

References:

[1] Moar JJ. Traumatic rupture of the thoracic aorta. An autopsy and histopathological study. S Afr Med J 1985;6:383-385.
[2] Ben-Menachem Y, Handel SF. The mechanism of injury. Angiography in trauma. A work atlas. London: WB Saunders, 1981.
[3] Richens D, Field M, Neale M, Oakley C. The mechanism of injury in blunt traumatic rupture of the aorta. Eur J CardiothoracSurg 2002;21:288-293.
[4] Sevitt S. The mechanisms of traumatic rupture of the thoracic aorta. Br J Surg 1977;64:166-173.
[5] PierangeliA et al. Delayed treatment of isthmic aortic rupture. Cardiovascular Surgery, 2000;8:280-283.
[6] Stemper BD, Yoganandan N, Pintar FA, Brasel KJ. Multiple subfailures characterize blunt aortic injury. J Trauma 2007;62:1171-1174.
[7] Parmly LF, Mattingly TW, Manion WC, Jahnke EJ Jr. Nonpenetrating traumatic injury of the aorta. Circulation 1958;17:1086-1101.
[8] Feczko JD et al. An autopsy case review of 142 nonpenetrating (blunt) injures of the aorta. J Trauma 1990;30:1294-1297.
[9] Burkhart HM, Gomez GA, Jacobson LE, Pless JE, Broadie TA. Fatal blunt aortic injuries: a review of 242 autopsy cases. J Trauma 2001;50:113-115.
[10] Ermenc B, Prijon T, Hočevar Z. Pathoanatomy and histology of traumatic aortic ruptures- an attempt of classification. In: International meeting on forensic medicine Alpe-Adria-Pannonia. Whiplash injury. Proceedings. Department of Forensic Medicine and Criminology Scool of Medicine, University of Zagreb. Croatian Medical Association. Opatija, Croatia, 23-26 May, 2001;212-218.
[11] Prijon T, Ermenc B, Balažic J, Štefanič B, Šerko A, Kralj E. Classification of blunt injuries to the thoracic aorta. Archive of Oncology 2002;10:10-11.
[12] Prijon T, Ermenc B. A systematic interpretation of aortic trauma and a proposed new classification of blunt aortic injuries. In: XXth Congress of International Academy of Legal Medicine, Budaperst 23-26 Avgust 2006. Editor Peter Sotony. Free papers proceedings; 87-91.
[13] Prijon T, Ermenc B. Classification of blunt aortic injuries - a new systematic overview of aortic trauma. Forensic Sci Int. 2010;195:6-9.
[14] Fitzharris M, Franklyn M, Frampton R, Yang K, Morris A, Fildes B. Thoracic aortic injury in motor vehicle crashes: the effect of impact direction, side of body struck, and seat belt use. J Trauma 2004;57:582- 590.
[15] Richens D, Kotidis K, Neale M, Oakley C, Fails A. Rupture of the aorta following road traffic accidents in the United Kingdom 1992-1999. The results of the co-operative cresh injury study. Eur J cardiothoracSurg 2003;23:143-148.
[16] Viano DC. Biomechanics of non-penetrating aortic trauma: a review. 27th Stapp car crash conference, 1983.
[17] Steenburg SD, Ravenel JG, Ikonomidis JS, Schönholz C, Reeves S. Acute Traumatic Aortic Injury: Imaging Evuluation and Managment. Radiology 2008; 248:748-762.
[18] Nienaber CA, Eagle KA. Aortic dissection; New frontiers in diagnosis and management. Part II: Therapeutic management and follow-up. Circulation 2003;108:772-778.
[19] Nienaber CA, Eagle KA. Aortic dissection; New frontiers in diagnosis and management. Part I: from etiology to diagnostic strategies. Circulation 2003;108:628-635.
[20] Siegal EM. Acute aortic dissection. J hosp Med 2006;1:94-105.
[21] Williams JS, Graff JA, Uku IM, Steinig JP. Aortic injury in vehicular trauma. Ann ThoracSurg 1994;57:762-730.
[22] Chiesa R, Liberato de Moura MR, Lucci C, Castellano R, Civilini E, Melissano G, Tshomba Y. Blunt trauma of the thoracic aorta: mechanisms involed, diagnosis and managment. J Vasc Br 2003;2 (3):197-210.
[23] Isselbacher EM. Disease of the aorta. In: Libby P, Bonow RO, Mann DL, Zipws DP, eds. Braunwald's Heart disease. A textbook of cardiovascular medicine. 8th ed. Philadelphia: Saunders Elsevier; 2008: 1457-1490.
[24] Dosios TJ, Salemis N, Angouras D, Nonas E. Blunt and penetranting trauma of the thoracic aorta and aortic arch branches: an autopsy study. J Trauma. 2000; 49: 696-703.
[25] Greendyke RM. Traumatic rupture of aorta; special reference to automobile accidents. JAMA 1966;195:527-530.
[26] Haunt RC. Biomechanics of soft tissues. In: Nahum AM, Melvin JW Editors, Accidental injury, Springer-Verlag, New York¸1993:224-246.
[27] Tanak TT, Fung YC. Elastic and inelastic properties of the canine aorta and their variation along the aortic tree. J Biomech. 1974; 7:357-370.
[28] Gotzen L, Flory PJ, Otte D. Biomechanics of aortic rupture at classical location in traffic accidents. ThoracCardiovascSurg 1980;28:64-68.
[29] McGwin G, Reiff DA, Moran SG, Rue LW. Incidence and characteristics of motor vehicle collision – related blunt thoracic injury according to age.
[30] Bertrand S, Cuny S, Petit P, Trosseille X, Page P, Guillemot H, et al. Traumatic rupture of thoracic aorta in real-world motor vehicle crashes. Traffic Injury Prevention. 2008:9;153-161.
[31] Newman RJ, Rastogi S. Rupture of the thoracic aorta and its relationship to road traffic accident characteristics. Injury.1984;15:296-299.
[32] Fabian TC, Richardson JD, Croce MA, et.al. prospective study of blunt aortic injury: multicenter trial of the American Association for the Surgery of Trauma. J Trauma 1997;42:374-380.
[33] Strassman G. Traumatic rupture of the aorta. Am Heart J, 1947; 33: 508.
[34] Lundervall J. The mechanism of traumatic rupture of the aorta. ActaPatholMicrobiolScand 1964;62:34-46.
[35] Horton TG, Cohn SM, Heid MP, et al. Indentification of trauma patients at risc of thoracic aortic tear by mechanism of injury. J Trauma 2000;48:1008-1013.
[36] Schulman CI, Carvajal D, Lopez PP, Soffer D, Habib F, Augenstein J. Incidence and crash mechanisms of aortic injury during the past decade. J Trauma 2007;62:664-667.
[37] Katyal D, McLellan BA, Brenneman FD, Boulanger BR, Sharkey PW, Waddell JP. Lateral impact motor vehicle collisions: significant cause of blunt traumatic rupture of the thoracic aorta. J Trauma 1997;42:769-772.
[38] Nikolic S, Atanasijević T, Mihalović Z, Babic D, Popovic-Loncar T. Mechanism of aortic blunt in fatally injured front-seat passengers in frontal car collisions: an autopsy study. Am J Forensic Med Pathol 2006; 27:292-295.