Diagnosis of Aortic Dissection

Diagnosis of Aortic Dissection

Lynn E. Sosa, Harvard Medical School, Year IIILynn E. Sosa, Harvard Medical School, Year IIIGillian Lieberman, MDGillian Lieberman, MD

Lynn Sosa

Gillian Lieberman, MD April 2001

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Lynn Sosa

Gillian Lieberman, MD

Patient BC

58 58 yoyo female presented to an OSH w/ neck and female presented to an OSH w/ neck and back pain x 24 hoursback pain x 24 hoursPMH significant for CAD, PMH significant for CAD, s/ps/p MI, hypertensionMI, hypertensionOn physical exam, the following was noted:On physical exam, the following was noted:

Systolic BP of 60 on the right and 120 on the Systolic BP of 60 on the right and 120 on the leftleft2/6 systolic murmur radiating to the carotids2/6 systolic murmur radiating to the carotidsStrong carotid/brachial pulses, weak Strong carotid/brachial pulses, weak femoral/femoral/poplitealpopliteal/pedal pulses/pedal pulses

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Lynn Sosa

Gillian Lieberman, MD

Differential Diagnosis

Myocardial infarctionMyocardial infarctionPericarditisPericarditisPulmonary embolusPulmonary embolusAortic DissectionAortic DissectionPatient became Patient became hypotensivehypotensive and was transferred to and was transferred to BIDMC where a CT scan was performedBIDMC where a CT scan was performed

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Lynn Sosa

Gillian Lieberman, MD

BC’s Chest CT

Courtesy of Chad Brecher, MD, BIDMC

**

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Lynn Sosa

Gillian Lieberman, MD

BC’s Aortic Dissection

Courtesy of Chad Brecher, MD, BIDMC

Intimal flap

Intimal flap

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Lynn Sosa

Gillian Lieberman, MD

Clinical Manifestations

Peak incidence 6Peak incidence 6thth--77thth decadesdecadesMen affected more often than womenMen affected more often than womenTwoTwo--thirds of patients have thirds of patients have hxhx of hypertensionof hypertensionMost common symptom is sudden severe chest Most common symptom is sudden severe chest pain with “tearing” or “ripping” qualitypain with “tearing” or “ripping” qualityComplications include: Complications include:

Rupture (pericardial Rupture (pericardial tamponadetamponade))Occlusion of aortic branch vessels (stroke, MI, Occlusion of aortic branch vessels (stroke, MI, splanchnicsplanchnic infarction)infarction)Distortion of aortic annulus (aortic regurgitation)Distortion of aortic annulus (aortic regurgitation)

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Lynn Sosa

Gillian Lieberman, MD

PathophysiologyThere are two theories:There are two theories:A. An A. An intimalintimal tear tear exposes the media to the exposes the media to the pressure of pressure of intraluminalintraluminal blood which then blood which then penetrates the medial layer penetrates the medial layer and cleaves it and cleaves it longitudinallylongitudinallyB. Rupture of the B. Rupture of the vasavasa vasorumvasorum within the media within the media leads to secondary rupture leads to secondary rupture through the through the intimaintima

From Braunwald: Heart Disease: A Textbook of Cardiovascular Medicine, 6th ed. 2001

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Lynn Sosa

Gillian Lieberman, MD

Risk factors

Advanced ageAdvanced ageHypertension (72Hypertension (72--80% of cases)80% of cases)Bicuspid aortic valveBicuspid aortic valveCollagen diseases (Collagen diseases (Marfan’sMarfan’s, Ehlers, Ehlers--DanlosDanlos))Congenital abnormalities (Congenital abnormalities (ieie CoarctationCoarctation))Turner, Noonan syndromesTurner, Noonan syndromesPregnancyPregnancyTrauma (esp. iatrogenic)Trauma (esp. iatrogenic)

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Lynn Sosa

Gillian Lieberman, MD

ClassificationClassification is based on Classification is based on origin and extension of the origin and extension of the dissectiondissection----65% occur in the 65% occur in the ascending aortaascending aorta----20% occur in the 20% occur in the descending aortadescending aorta----10% occur in the aortic 10% occur in the aortic archarch----5% occur in the 5% occur in the abdominal aortaabdominal aortaDissection in the Dissection in the ascending aorta requires ascending aorta requires surgerysurgery

From Braunwald: Heart Disease: A Textbook of Cardiovascular Medicine, 6th ed. 2001

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Lynn Sosa

Gillian Lieberman, MD

Our Patient BC: Stanford Type A Aortic Dissection

Courtesy of Chad Brecher, MD, BIDMC

Intimal flap

True lumen

False lumen

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Lynn Sosa

Gillian Lieberman, MD

Our Patient BC: Extension of Dissection into Abdomen

Courtesy of Chad Brecher, MD, BIDMC

Intimal flap

Portal venous air

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Lynn Sosa

Gillian Lieberman, MD

Imaging StudiesThe best imaging modality should:The best imaging modality should:

Confirm/refute the diagnosis Confirm/refute the diagnosis Determine location/origin of the dissectionDetermine location/origin of the dissectionIdentify certain anatomical features including: extent, Identify certain anatomical features including: extent, sites of entry/resites of entry/re--entry, presence of thrombus, branch vessel entry, presence of thrombus, branch vessel involvement, presence of AR, pericardial effusion, coronary involvement, presence of AR, pericardial effusion, coronary artery involvementartery involvement

Imaging options for dissection include:Imaging options for dissection include:CXRCXRAortographyAortographyContrastContrast--enhanced CT enhanced CT MRIMRITTE/TEETTE/TEE

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Lynn Sosa

Gillian Lieberman, MD

Patient 2: Chest X-RayMost common finding is Most common finding is widening of the aortic silhouette widening of the aortic silhouette (81(81--90%)90%)“Calcium sign”“Calcium sign”-- calcification of calcification of the aortic knob with separation the aortic knob with separation of the of the intimalintimal calcification from calcification from the outer aortic soft tissue the outer aortic soft tissue border by more than 1cmborder by more than 1cm------suggestive of dissectionsuggestive of dissectionCXR is often non diagnosticCXR is often non diagnostic--up to 12% are normalup to 12% are normal

Sternal wires

Courtesy of Chad Brecher, MD, BIDMC

Calcium sign

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Lynn Sosa

Gillian Lieberman, MD

AortographyFirst modality for accurate diagnosis of dissectionFirst modality for accurate diagnosis of dissectionLook for two Look for two luminalumina or an or an intimalintimal flap (diagnostic)flap (diagnostic)Indirect signs: deformity of the aortic lumen, thickening of Indirect signs: deformity of the aortic lumen, thickening of aortic walls, branch vessel abnormalities, aortic aortic walls, branch vessel abnormalities, aortic regurgitationregurgitationSensitivity: 77Sensitivity: 77--88%, Specificity 94%88%, Specificity 94%AdvantagesAdvantages

Can determine extent/branch vessel involvementCan determine extent/branch vessel involvementIdentification of complications (AR, coronary artery involvementIdentification of complications (AR, coronary artery involvement))

DisadvantagesDisadvantagesInvasiveInvasiveDelayed time to procedureDelayed time to procedureLength of procedureLength of procedure

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Lynn Sosa

Gillian Lieberman, MD

Patient 3: Example of Dissection Involving the Left Renal Artery

From Braunwald: Heart Disease: A Textbook of Cardiovascular Medicine, 6th ed. 2001

Right renal artery

Left renal artery

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Lynn Sosa

Gillian Lieberman, MD

CT ScanAssess for two distinct aortic Assess for two distinct aortic luminalumina by presence of an by presence of an intimalintimal flap or differential rate of contrast flap or differential rate of contrast opacificationopacificationSensitivity: 83Sensitivity: 83--96%, Specificity: 8796%, Specificity: 87--100% 100% AdvantagesAdvantages

Rapid access emergentlyRapid access emergentlyNoninvasiveNoninvasiveCan detect presence of thrombus in false lumen and pericardial Can detect presence of thrombus in false lumen and pericardial effusioneffusion

DisadvantagesDisadvantagesRequires IV contrastRequires IV contrastCannot usually identify site of Cannot usually identify site of intimalintimal teartearOnly identify Only identify intimalintimal flap in 75% of casesflap in 75% of cases

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Lynn Sosa

Gillian Lieberman, MD

Patient 2: Hemorrhage into False Lumen

Courtesy of Chad Brecher, MD, BIDMC

True lumen

False lumen

Falselumen

Hematomawithin falselumen

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Lynn Sosa

Gillian Lieberman, MD Patient 2: CT Reconstruction of Aortic Dissection

Courtesy of Chad Brecher, MD, BIDMC

True lumen

Falselumen

Thrombus infalse lumen

Intimalflap

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Lynn Sosa

Gillian Lieberman, MD

Magnetic Resonance ImagingCurrent gold standard for diagnosis of aortic dissectionCurrent gold standard for diagnosis of aortic dissectionLook for double lumen, visible Look for double lumen, visible intimalintimal flapflapSensitivity/Specificity: 98%Sensitivity/Specificity: 98%Advantages Advantages

NoninvasiveNoninvasiveNo IV contrast or radiation requiredNo IV contrast or radiation requiredHighHigh--quality images in several planesquality images in several planesCan assess for involvement of branch vessels, ARCan assess for involvement of branch vessels, AR

DisadvantagesDisadvantagesNot usually available on emergent basisNot usually available on emergent basisContraindicated in patients w/ pacemakers, surgical clips, Contraindicated in patients w/ pacemakers, surgical clips, certain prosthetic heart valvescertain prosthetic heart valvesLength of studyLength of studySafety concerns for unstable patientsSafety concerns for unstable patients

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Lynn Sosa

Gillian Lieberman, MD

Patient 4: Intimal Flap on MRI

BIDMC

Intimal flap

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Lynn Sosa

Gillian Lieberman, MD

Patient 4: Involvement of Left Iliac Artery

BIDMC

Intimal flap

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Lynn Sosa

Gillian Lieberman, MD

EchocardiographyPoor sensitivity/specificity for TTE limits usePoor sensitivity/specificity for TTE limits useTEE: Sensitivity 98TEE: Sensitivity 98--99%, Specificity 7799%, Specificity 77--97%97%Assess for presence of undulating Assess for presence of undulating intimalintimal flap separating flap separating two two luminaluminaAdvantagesAdvantages

NoninvasiveNoninvasiveFastFastCan be performed at the bedsideCan be performed at the bedsideCan look for entry/reCan look for entry/re--entry sitesentry sites

DisadvantagesDisadvantagesContraindicated in esophageal diseaseContraindicated in esophageal diseasePoor visualization of distal ascending aorta and proximal archPoor visualization of distal ascending aorta and proximal arch

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Lynn Sosa

Gillian Lieberman, MD

Patient 5: Aortic Dissection on TEE

T

F I E

T

F

From Flachskampf, FA and WG Daniel. Transesophageal Echocardiography: Aortic Dissection. Cardiology Clinics. 18 (4): 807-817.

F = false lumenT = true lumenE = entry pointI = intimal flap

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Lynn Sosa

Gillian Lieberman, MD

Patient 6: Undulating Intimal Flap

Leaflets of aortic valve

Intimal flap

From Flachskampf, FA and WG Daniel. Transesophageal Echocardiography: Aortic Dissection. Cardiology Clinics. 18 (4): 807-817.

Movement ofintimal flapduring systole

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Lynn Sosa

Gillian Lieberman, MD

Summary

Aortic dissection should always be considered in Aortic dissection should always be considered in the differential in patients presenting with chest the differential in patients presenting with chest pain and a pain and a hxhx of hypertensionof hypertensionInvolvement of the ascending aorta is a surgical Involvement of the ascending aorta is a surgical emergencyemergencyThe best diagnostic studies are MRI and TEE but The best diagnostic studies are MRI and TEE but there is still an important role for CT as wellthere is still an important role for CT as well

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Lynn Sosa

Gillian Lieberman, MD

ReferencesBraunwaldBraunwald. “Aortic Dissection.” . “Aortic Dissection.” Heart Disease: A Textbook of Heart Disease: A Textbook of Cardiovascular MedicineCardiovascular Medicine. WB Saunders, 2001. 1431. WB Saunders, 2001. 1431--1448.1448.FlachskampfFlachskampf FA, Daniel WG. FA, Daniel WG. TransesophagealTransesophageal echocardiography: aortic echocardiography: aortic dissection. dissection. CardiolCardiol ClinClin 18: 80718: 807--817, 2000.817, 2000.Manning WJ. Clinical manifestations and diagnosis of aortic disManning WJ. Clinical manifestations and diagnosis of aortic dissection. section. UpToDateUpToDate, 2001., 2001.<http://<http://www.uptodate.comwww.uptodate.com/>/>McDonough, CG and McDonough, CG and CreagerCreager, MA. “Diseases of the Peripheral Vasculature.” , MA. “Diseases of the Peripheral Vasculature.” PathophysiologyPathophysiology of Heart Diseaseof Heart Disease. Lilly. Baltimore: Lippincott, Williams . Lilly. Baltimore: Lippincott, Williams and Wilkins, 1998. 307and Wilkins, 1998. 307--309. 309. TorossovTorossov M, Singh A, Fein SA. Clinical presentation, diagnosis, and hosM, Singh A, Fein SA. Clinical presentation, diagnosis, and hospital pital outcome of patients with documented aortic dissection: the outcome of patients with documented aortic dissection: the albanyalbany medical medical center experience, 1986 to 1996. Am Heart J 137: , 1999.center experience, 1986 to 1996. Am Heart J 137: , 1999.

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Gillian Lieberman, MD

Acknowledgements

Chad Chad BrecherBrecher, MD, MDRachel Van Rachel Van SambeekSambeek, HMS III, HMS IIIRaymond Liu, HMS IIIRaymond Liu, HMS IIIBeverleeBeverlee TurnerTurnerGillian Lieberman, MDGillian Lieberman, MDLarry Barbaras and Cara Lyn D’amourLarry Barbaras and Cara Lyn D’amour