Aortic Dissection Clinical Presentation, Diagnosis and Medical Management Adoracion N. Abad, M.D.

Aortic Dissection not very common, but challenging, frequently fatal, emergency clinical condition keys to improve outcome: –high index of suspicion –prompt diagnosis and treatment

Predisposing Factors HPN – 62-78% aortic disease –aortic dilatation/aneurysm –annulo-aortic dysplasia –chromosomal aberration Turner’s syndrome Noonan’s syndrome –aortic arch hypoplasia –coarctation of aorta –bicuspid AV –heredetary CTD Marfan’s syndrome Ehler’s Danlos syndrome

Predisposing Factors Cont… traumatic injury –arterial cannulation during surgery –catheter based diagnostic or therapeutic intervention –chest trauma –high intensity weight lifting or other strenuous R training cocaine β blocker withdrawal women <40, 50% occurs during pregnancy –HPN in 25-50%

Clinical Presentation CP – severe,abrupt, sharp or “tearing” (72.7%) –ant. CP – dissection in asc Ao –post. CP or back pain or abdominal pain - distal to L subclavian –can radiate anywhere in the thorax or abdomen –can occur alone or associated with: syncope M.I. CVA CHF

Clinical Presentation Cont… HPN – more common in type B (70% vs 35%) CHF – (7%) syncope – (12.7%) cardiac arrest or sudden death neurologic – CVA paralysis M.I. – (1-2%) –involvement of coronaries –RCA>L –with thrombolytic – mortality >70%

Clinical Presentation cont… Involvement of desc. Ao sphlancnic ischemia renal insufficiency lower extremity ischemia spinal cord ischemia CP or back pain 86% HPN 69% abdominal pain 43% hypotension/shock 3% abrupt onset 89% peripheral neuropathy 2% migratory pain 25% ARF 14 % IRAD Registry

Differential Diagnosis myocardial ischemia M.I. with or w/o ST elevation pericarditis pulmonary embolism AR without dissection AA with dissection musculoskeletal pain mediastinal tumor pleuritis PUD/perforating ulcers acute pericarditis

Diagnosis of Aortic Dissection Prediction model for early diagnosis of Ao dissection –In analysis of 250 patients with CP or back pain, 128 with dissection –96% can be identified by combination of 3 clinical predictors: 1.immediate onset of CP with tearing and or ripping character 2.mediastinal and or aortic widening on xray 3.variation in pulse BP > 20 mmHg between R and L arm

Diagnosis of Aortic Dissection cont… when all variables absent7% aortic pain 31% mediastinal/Ao widening 39% pulse or BP difference or any combination of the 3 83% incidence of dissection Von Kodolitsch et al., Arch Intern Med 2000;160:

Diagnostic Procedures CXR –widening of mediastinum (60-70% sensitivity) –Ca sign – separation of intimal calcification from outer aortic soft tissue border by 1 cm

Diagnostic Procedures ECG –no specific findings associated with dissection –1/3 – LVH –1/3 – normal –ischemia

Diagnostic Procedures TEE –can be done fast, safely and in any environment high sensitivity up to 98% high specificity up to 97% –specifically informative ARostia of coronaries involved PECT

Diagnostic Procedures TEE limitations: –unable to visualize distal ascending and descending abdominal aorta –technically difficult in esophageal structures or varices

Diagnostic Procedures CT Scan –identifies 2 distinct lumen with intimal flap –sensitivity with contrast % no contrast % –specificity with contrast % no contrast % advantages: –readily available in most hospitals even on emergency basis –identifies intraluminal thrombus and PE

Diagnostic Procedures limitations: –intimal flap seen in < 75% –site of entry rarely identified –contrast potentially nephrotoxic –cannot assess AR or coronary involvement

Diagnostic Procedures Spiral CT –gives accurate 3D view of aorta sensitivity – % specificity – % –disadvantages Potentially nephrotoxic, site of entry difficult

Initial interpretation was findings c/w aortic dissection, with thrombosis of the false lumen. Only a small amount of flow is present in the false channel at this point in time, suggesting the dissection may be healing, and stablilizing.

Diagnostic Procedures MRI –currently gold standard sensitivity – 98% specificity – 98% –determines location of intimal tear, secondary tears and branched vessels –no contrast needed –can detect AR –disadvantages limited availability time consuming contraindicated in metallic implants

Diagnostic Procedures Aortography sensitivity – 86-88% specificity – 75% –procedure of choice in earlier days –now rarely used because it is invasive, needs contrast and consumes time

What is the Best Modality? Depends on: –accesibility –expertise of the institution

Management General principle –Aortic dissection of ascending aorta – surgical emergency –If confined to descending aorta – medical except when there is hemorrhage into pleural or retroperitoneal space –In all – prompt control of BP if HPN present

Management Medical –uncomplicated distal dissection –stable dissection isolated to aortic arch –stable chronic dissection

Medical Management ICU admission target BP – mmHg SBP or lowest level tolerated to dP/dT (force of ejection of flow from LV) –nitroprusside/nicardepine –β blocker (esmolol, propranolol or labetatol) if β blocker contraindicated –verapamil or diltiazem if with refractory HPN –evaluate renal artery involvement

“Disease is very old, and nothing about it has changed It is us who change as we learn to recognize what was formerly imperceptible” Dr. Jean Martin Charcot

Take Home Message Despite recent advancement in diagnosis and treatment, mortality remains high We need to continue improvement in prevention, prompt diagnosis and management of this frequently fatal condition

Thank You!