Thoracic Aortic Dissection

8/6/2019 Thoracic Aortic Dissection

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PEARLS ON THORACIC AORTAPEARLS ON THORACIC AORTADISSECTIONDISSECTION

1. This is not an ³old person¶s disease´ as the1. This is not an ³old person¶s disease´ as theaverage age of patients in a review of average age of patients in a review of

Canadian Medical Protective AssociationCanadian Medical Protective Association(CMPA) files was only 49 years with a range(CMPA) files was only 49 years with a rangeof 18of 18 ± ± 79 years.79 years.



2 .2 . 10% of pts will10% of pts will NOTNOT have pain, insteadhave pain, insteadpresenting with syncope or focal neurologicalpresenting with syncope or focal neurologicalfindings such as stroke, decreased LOC andfindings such as stroke, decreased LOC andparaplegia (when the dissection involves theparaplegia (when the dissection involves theanterior spinal artery).anterior spinal artery).



3 . Other descriptors of the pain such as ³sharp´3 . Other descriptors of the pain such as ³sharp´are more commonly used than "tearing´.are more commonly used than "tearing´.

pain is usually sudden in onset and alsopain is usually sudden in onset and alsomaximal at onsetmaximal at onsetsurprisingly, pleural or positional pain wassurprisingly, pleural or positional pain waspresent in 44% of the patients in the CMPApresent in 44% of the patients in the CMPA

review (tearing pain was only described by 1review (tearing pain was only described by 1of 32 patients)of 32 patients)



4. The pain can be in the anterior chest as well as4. The pain can be in the anterior chest as well asother less common locations such as the neck,other less common locations such as the neck,

jaw, abdomen and lumbar areas. The latter jaw, abdomen and lumbar areas. The latter two locations occur when the dissection hastwo locations occur when the dissection hasextended distal to the diaphragm.extended distal to the diaphragm.

the pain is frequently NOT radiating inthe pain is frequently NOT radiating innaturenature



5 . The most consistent finding on the physical5 . The most consistent finding on the physicalexam is a sick looking patient. Other findingsexam is a sick looking patient. Other findingsinclude:include:

a new aortic regurgitation murmur in approximatelya new aortic regurgitation murmur in approximately1/3 of patients1/3 of patientsa difference > 2 0 mm Hg in the systolic blooda difference > 2 0 mm Hg in the systolic bloodpressure between the two armspressure between the two arms

history of hypertension is commonhistory of hypertension is common

focal neurological abnormalitiesfocal neurological abnormalitiesfindings of pericardial tamponade (hypotension,findings of pericardial tamponade (hypotension,JVD, muffled heart sounds, etc.)JVD, muffled heart sounds, etc.)



6 . The chest x6 . The chest x- -ray isray isnormal in ~ 10% of normal in ~ 10% of patients ( 3 0% in thepatients ( 3 0% in theCMPA review). TheCMPA review). Themost common findingmost common findingis a widenedis a widenedmediastinummediastinum (>7.5 (>7.5 cm) .cm) .



Other findings include:Other findings include:obliteration of the aortic knobobliteration of the aortic knobdisplacement of the trachea to the right or leftdisplacement of the trachea to the right or leftif a nasogastric tube is in place it may also beif a nasogastric tube is in place it may also bedisplaced to the right or leftdisplaced to the right or leftdouble density appearance of the aorta whichdouble density appearance of the aorta whichis created when a false lumen has beenis created when a false lumen has been

formed by the dissection in addition to the trueformed by the dissection in addition to the truelumen of the aortalumen of the aorta



the calcified aortic wall will appear to bethe calcified aortic wall will appear to bedisplaced away from the lumen of the aortadisplaced away from the lumen of the aortaleft pleural effusionleft pleural effusiondepression of left main stem bronchusdepression of left main stem bronchusdiscrepancy in the diameter of the ascendingdiscrepancy in the diameter of the ascendingand descending aortaand descending aorta



8. Transesophageal echocardiography (TEE) and8. Transesophageal echocardiography (TEE) andCT scanning are highly sensitive and specific for CT scanning are highly sensitive and specific for diagnosing a dissection of the thoracic aorta.diagnosing a dissection of the thoracic aorta.

Unfortunately, it is not practical to do one of theseUnfortunately, it is not practical to do one of theseexaminations on every patient who presents withexaminations on every patient who presents with

anterior chest, neck, jaw, abdominal or lumbar anterior chest, neck, jaw, abdominal or lumbar painpain



9.9. The DThe D -- dimer test plays an important role indimer test plays an important role inscreeningscreening low risklow risk patients (high risk patientspatients (high risk patientswill go directly to TEE or CT scanning)will go directly to TEE or CT scanning)

blood clots are formed as the dissectionblood clots are formed as the dissectionoccurs and then break down spontaneouslyoccurs and then break down spontaneouslyresulting in the production of Dresulting in the production of D - - dimersdimerswhich are a fibrin degradation productwhich are a fibrin degradation producta recent review demonstrated that Da recent review demonstrated that D - -dimers are positive in 90% of dissections of dimers are positive in 90% of dissections of the thoracic aortathe thoracic aorta



a false negative Da false negative D - - dimer is more frequent if dimer is more frequent if testing within 2 hrs. of the onset of symptomstesting within 2 hrs. of the onset of symptomsas in pulmonary embolism, there are manyas in pulmonary embolism, there are manycauses of an elevated Dcauses of an elevated D ± ± dimer so thatdimer so thatconfirmation is required by TEE or CTconfirmation is required by TEE or CTscanningscanning

may result in increased CT scanningmay result in increased CT scanning



10. Once the diagnosis has been established,10. Once the diagnosis has been established,initiate stabilization and then call a CV/thoracicinitiate stabilization and then call a CV/thoracicsurgeon as quickly as possiblesurgeon as quickly as possible

surgery is usually required for dissections of surgery is usually required for dissections of the ascending aortathe ascending aortadescending aorta dissectionsdescending aorta dissections may may bebe

managed medically withmanaged medically with BB--blockers to lower blockers to lower the pulse and bp and thus decrease stress onthe pulse and bp and thus decrease stress onthe dissection sitethe dissection site



the CMPA made the following statementthe CMPA made the following statementregarding thoracic aorta dissections:regarding thoracic aorta dissections:³³The diagnosis may elude even the most The diagnosis may elude even the most experienced and knowledgeable clinicians´.experienced and knowledgeable clinicians´.

however, your documentation must reflect thathowever, your documentation must reflect thatyou considered this diagnosis and madeyou considered this diagnosis and madereasonable steps to rule it outreasonable steps to rule it out

Source: Marill et al. "Serum DSource: Marill et al. "Serum D - - dimer is a Sensitive Tool for the Detection of Acutedimer is a Sensitive Tool for the Detection of Acute Aortic Dissection: A Pooled Meta Aortic Dissection: A Pooled Meta - - Analysis. The Journal of Emergency Medicine, Analysis. The Journal of Emergency Medicine,

February 2 007February 2 007CMPA. ³Aortic Dissections: Tearing Apart the Data´. Risk Identification for AllCMPA. ³Aortic Dissections: Tearing Apart the Data´. Risk Identification for All

Physicians, June 2 008Physicians, June 2 008

Thoracic Aortic Dissection

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