Disorders of the Aorta

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Disorders of the Aorta

Chapter 38

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Aorta

Largest artery

Responsible for supplying oxygenated blood to essentially all vital organs


Disorders of the Aorta

Most common vascular problems of aorta

Aneurysms

Aortoiliac occlusive disease

Aortic dissection


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Aortic Aneurysms


Aortic AneurysmsDefinition

Outpouching or dilation of the arterial wall

Common problems involving aorta

Occur in men more often than in women

Incidence ↑with age


Abdominal Aortic Aneurysm


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Aortic AneurysmsDefinition

Abdominal aortic aneurysms (AAA)

Affect about 1.1 million adults between 55 and 84 years of age

Most occur below renal arteries


Aortic AneurysmsEtiology and Pathophysiology

May have aneurysm in more than one location

Aorta larger than 3 cm in diameter is considered aneurysmal

Growth rate unpredictable

The larger the aneurysm, the greater the risk of rupture



Dilated aortic wall becomes lined with thrombi that can embolize

Leads to acute ischemic symptoms in distal branches


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Case Study

E.O., a 74‐year‐old woman, comes to the ED with deep chest pain radiating throughout the chest to the back.

She reports that she smoked 1 pack of cigarettes/day for 20 years, quitting 5 years ago.

She weighs 212 lb.


iStockphoto/Thinkstock


Causes

Degenerative

Congenital

Mechanical

Penetrating or blunt trauma

Inflammatory

Infectious


Age

Male gender

High blood pressure (BP)

Coronary artery disease

Family history

High cholesterol

Lower extremity PAD

Carotid artery disease

Previous stroke

Aortic AneurysmsRisk Factors


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Smoking

Being overweight or obese

White and Native Americans have higher risk than African Americans, Hispanics, and American Asians.

Aortic AneurysmsRisk Factors


Bicuspid aortic valve Coarctation of the aorta Turner’s syndromeAutosomal dominant polycystic kidney disease Ehlers‐Danlos syndrome Loeys‐Dietz syndromeMarfan’s syndrome

Aortic AneurysmsGenetic Link


Aortic AneurysmsClassification

Two basic classifications

True

False


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True vs. False Aneurysm



True aneurysm

Wall of artery forms the aneurysm

At least one vessel layer still intact



True aneurysm

Further subdivided

Fusiform

Circumferential, relatively uniform in shape

Saccular

Pouchlike with narrow neck connecting bulge to one side of arterial wall


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False aneurysm

Also called pseudoaneurysm

Not an aneurysm

Disruption of all layers of arterial wall

Results in bleeding contained by surrounding structures


Aortic AneurysmClinical Manifestations

Thoracic aorta aneurysms

Often asymptomatic

Most common manifestation

Deep diffuse chest pain

Pain may extend to the interscapular area



Ascending aorta/aortic arch

Angina

Hoarseness

If presses on superior vena cava

Decreased venous return

Distended neck veins

Edema of face and arms


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Abdominal aortic aneurysms (AAA)

Often asymptomatic

Frequently detected

On physical exam

When patient examined for unrelated problem (i.e., CT scan, abdominal x‐ray)



AAA

May mimic pain associated with abdominal or back disorders

May spontaneously embolize plaque

Causing “blue toe syndrome”

Patchy mottling of feet/toes with presence of palpable pedal pulses


Case Study

Based on E.O.’s symptoms, which type of aneurysm would you suspect?

What are the immediate concerns for her?



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Aortic AneurysmComplications

Rupture—serious complication

Rupture into retroperitoneal space

Bleeding may be tamponaded by surrounding structures, thus preventing exsanguination and death.

Severe back pain

May/may not have back/flank ecchymosis


Aortic AneurysmComplications

Rupture—serious complication related to untreated aneurysm

Rupture into thoracic or abdominal cavity

Massive hemorrhage

Most do not survive long enough to get to the hospital



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Aortic AneurysmDiagnostic Studies

X‐rays

Chest – demonstrate mediastinal silhouette and any abnormal widening of thoracic aorta

Abdomen – may show calcification within wall of AAA

ECG – to rule out MI



Echocardiography

Assists in diagnosis of aortic valve insufficiency

Ultrasonography

Useful in screening for aneurysms

Monitors aneurysm size



CT scan Most accurate test to determine Anterior‐to‐posterior length

Cross‐sectional diameter

Presence of thrombus

Best type of surgical repair

MRI Diagnose and assess the location and severity


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Angiography

Anatomic mapping of aortic system using contrast

Not reliable method of determining diameter or length

Can provide accurate information about involvement of intestinal, renal, or distal vessels


Aortic AneurysmCollaborative Care

Goal – prevent aneurysm from rupturing

Early detection/treatment imperative

Once detected

Studies done to determine size and location


Case Study

E.O. has an ECG in the ED that rules out an acute MI.

Chest x‐ray is suspicious for thoracic aneurysm.

She is now scheduled to go to radiology for CT scan of her chest.



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If carotid and/or coronary artery obstruction present, may need to correct before repair Small aneurysm (4‐ 5.5 cm) Conservative therapy used Risk factor modification

↓ blood pressure Ultrasound, MRI, CT scan monitoring annually



5.5 cm is threshold for repair Intervention at >5 cm in women with AAA

Surgical intervention may occur earlier in Patients with a genetic disorder

Rapidly expanding aneurysm

Symptomatic patients

High rupture risk


Case Study

E.O. returns from CT scan with a diagnosis of a thoracic aortic aneurysm measuring 5.2 cm.

A surgical consult is ordered and E.O. is scheduled for surgery in the next hour.



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Surgical therapy

If ruptured, emergent surgical intervention required

90% mortality with ruptured AAAs

Preop

Hydration

Stabilize electrolytes, coagulation, and hematocrit



Surgical technique

Open aneurysm repair (OAR)

Incising diseased segment of aorta

Removing intraluminal thrombus or plaque



Surgical technique –OAR

Inserting synthetic graft

Dacron or polytetrafluoroethylene (PTFE)

Suturing the native aortic wall around graft

Acts as protective cover


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Surgical Repair of Aneurysm



Autotransfusion reduces need for blood transfusion during surgery

AAA resection

Require cross‐clamping of aorta proximal and distal to aneurysm

Can be completed in 30 to 45 minutes

Clamps are removed and blood flow to lower extremities is restored



AAA resections If extends above renal arteries or if cross‐clamp must be applied above renal arteries Check for adequate renal perfusion after clamp removal and before closure of incision.

Risk of postop renal complications ↑significantly when repair is above renal arteries.


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Endovascular graft procedure

Alternative to conventional surgical repair

Involves placement of sutureless aortic graft into abdominal aorta inside aneurysm

Minimally invasive

Done through femoral artery cutdown




Graft

Constructed from Dacron cylinder

Surface supported with rings of flexible wire

Delivered through sheath to predetermined point


EVAR


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Graft

Deployed against vessel wall by balloon inflation

Anchored to vessel by series of small hooks




Blood then flows through graft, preventing expansion of aneurysm

Aneurysm wall will begin to shrink over time

Must meet strict eligibility criteria to be a candidate



Endovascular graft procedure Benefits

↓ anesthesia and operative time

Smaller operative blood loss

↓morbidity and mortality

More rapid resumption of physical activity

Shortened hospital stay

Quicker recovery

Higher patient satisfaction

Reduction in overall costs


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Potential complications

Endoleak

Aneurysm growth

Aneurysm rupture

Aortic dissection

Bleeding




Potential complications

Stent migration

Renal artery occlusion

Graft thrombosis

Incisional site hematoma

Site infection




Graft dysfunction may require traditional surgical repair

Need for long‐term follow‐up


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Intraabdominal hypertension (IAH)

Potentially lethal complication in emergency repair

Associated with abdominal compartment syndrome (ACS)

Reduces blood flow to viscera

End‐organ perfusion impaired



Nursing ManagementAssessment

Thorough history and physical exam

Watch for signs of cardiac, pulmonary, cerebral, and lower extremity vascular problems

Establish baseline data to compare postoperatively


Case Study

E.O.’s assessment findings include

Alert and oriented to person and place‐disoriented to time

BP 158/98, P 92, R 22

Verbalizes pain at 6 on 0‐10 scale

Bilateral pedal pulses audible by Doppler



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Note quality and character of peripheral pulses and neurologic status

Mark/document pedal pulse sites and any skin lesions on lower extremities before surgery



Monitor for indications of rupture

Diaphoresis

Pallor

Weakness

Tachycardia

Hypotension



Monitor for indications of rupture

Abdominal, back, groin, or periumbilical pain

Changes in level of consciousness

Pulsating abdominal mass


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Nursing ManagementPlanning

Overall goals include

Normal tissue perfusion

Intact motor and sensory function

No complications related to surgical repair


Nursing ManagementNursing Implementation

Health promotion

Alert for opportunities to teach health promotion to patients and their caregivers

Encourage patient to reduce cardiovascular risk factors

These measures help ensure graft patency after surgery



Acute intervention

Patient/caregiver teaching

Providing emotional support for patient/caregiver

Careful assessment of all body systems


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Case Study

E.O.’s daughter is called and arrives in the E.D.

Her daughter is very anxious and has many questions regarding the impending surgery.




Acute intervention

Preop teaching

Brief explanation of disease process

Planned surgical procedure

Preop routines

Bowel prep

NPO

Shower

IV antibiotics right before incision made



Acute intervention

Preop teaching

Expectations after surgery

Recovery room, tubes, drains

ICU

Beta blocker


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Acute intervention

Postop

ICU monitoring

Arterial line

Central venous pressure (CVP) or pulmonary artery (PA) catheter

Mechanical ventilation

Peripheral IV lines

Urinary catheter



Acute intervention

Postop

ICU monitoring

Nasogastric tube

ECG

Pulse oximetry

Pain medication


Case Study

E.O.’s surgery goes well and she arrives in ICU.

What are your priorities in monitoring her in the immediate postoperative period?



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Acute intervention

Postop

Maintain graft patency

Normal blood pressure

IV fluids and blood components

CVP or PA pressure monitoring

Urinary output monitoring

Avoid severe hypertension Drug therapy may be indicated



Acute Intervention

Postop

Cardiovascular status

Continuous ECG monitoring

Electrolyte monitoring

Arterial blood gas monitoring

Oxygen administration

Antidysrhythmic and antihypertensive meds

Pain control

Resume cardiac medications



Acute intervention

Postop

Infection

Antibiotic administration

Assessment of body temperature

Monitoring of WBC

Adequate nutrition

Observe surgical incision for signs of infection


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Acute intervention

Postop

GI status

Record amount and character of NG tube output

Abdominal assessment

Passing of flatus = return of bowel function

Assess for signs of bowel ischemia



Acute intervention

Postop

Neurologic status

Level of consciousness

Pupil size and response to light

Facial symmetry

Speech

Ability to move upper extremities

Quality of hand grasps



Acute Intervention

Postop

Peripheral perfusion status

Pulse assessment Mark pulse locations with felt‐tip pen


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Acute intervention

Postop

Peripheral perfusion status

Extremity assessment Temperature, color, capillary refill time, sensation, and movement of extremities

May need to use a Doppler to assess



Acute intervention

Postop

Renal perfusion status

Urinary output

Fluid intake

Daily weight

CVP/PA pressure

Blood urea nitrogen/creatinine


Case Study

E.O. progresses well through the postoperative phase and is scheduled to be discharged.

Her daughter is present and they are ready for discharge instructions.



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Ambulatory and home care

Encourage patient to express concerns

Instruct patient to gradually increase activities

No heavy lifting

Teach about signs and symptoms of complications

Infection

Neurovascular changes


Nursing ManagementEvaluation

Expected outcomes

Patent arterial graft with adequate distal perfusion

Adequate urine output

No signs of infection


Aortic Dissection


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Aortic Dissection

Often misnamed “dissecting aneurysm”

Not a type of aneurysm

Result of a false lumen through which blood flows

Classified by location and duration of onset


Aortic Dissection


Aortic Dissection


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Aortic Dissection

Affects men more often than women

Occurs most frequently between sixth and seventh decades of life


Aortic DissectionEtiology and Pathophysiology

Due to degeneration of the elastic fibers in the arterial wall

Chronic hypertension hastens the process

Tear in inner layer allows blood to “track” between inner and middle layer


Aortic DissectionEtiology and Pathophysiology

As heart contracts, each systolic pulsation ↑ pressure on damaged area

Further ↑ dissection

May occlude major branches of aorta

Cutting off blood supply to brain, abdominal organs, kidneys, spinal cord, and extremities


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Aortic DissectionClinical Manifestations

Depend on location of intimal tear and extent of dissection



Pain characterized as

Sudden, severe pain in anterior part of chest, or intrascapular pain radiating down spine to abdomen or legs

Described as “sharp” and “worst ever”

May mimic that of MI



Cardiovascular, neurologic, and respiratory signs may be present

If aortic arch involved

Neurologic deficiencies may be present


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Aortic DissectionComplications

Cardiac tamponade

Severe, life‐threatening complication

Occurs when blood escapes from dissection into pericardial sac



Cardiac tamponade

Clinical manifestations include

Hypotension

Narrowed pulse pressure

Distended neck veins

Muffled heart sounds

Pulsus paradoxus



Aorta may rupture

Results in exsanguination and death

Hemorrhage may occur in mediastinal, pleural, or abdominal cavities

Occlusion of arterial supply to vital organs


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Aortic DissectionDiagnostic Studies

ECG to rule out MI

Chest x‐ray

3‐D CT scan

Transesophageal echocardiography

MRI


Aortic DissectionCollaborative Care

Initial goal

↓ BP and myocardial contractility to diminish pulsatile forces within aorta



Drug therapy

IV β‐adrenergic blocker

Esmolol (Brevibloc)

Other antihypertensive agents

Calcium channel blockers

Nitroprusside

Angiotensin‐converting enzyme inhibitors

MorphineCopyright © 2014 by Mosby, an imprint of Elsevier Inc.

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Conservative therapy

If no symptoms

Can be treated conservatively for a period of time

Pain relief and BP control



Endovascular dissection repair

Standard to treat acute descending aortic dissections with complications

Similar to EVAR



Surgical therapy

Emergency surgery for acute ascending aortic dissection

When drug therapy is ineffective or when complications of aortic dissection are present

Surgery is delayed to allow edema to decrease and to permit clotting of blood


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Surgical therapy

Involves resection of aortic segment and replacement with synthetic graft material

Women experience poorer surgical outcomes and higher mortality than men


Aortic DissectionNursing Management

Preoperative

Semi‐Fowler’s position

Maintaining a quiet environment

Anxiety and pain management

Opioids and tranquilizers as ordered

Continuous IV administration of antihypertensive agents



Preoperative

Continuous ECG and intraarterial pressure monitoring

Observation of changes in quality of peripheral pulses

Frequent vital signs


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Postoperative See aneurysm postop care (discussed earlier)

Discharge teaching Therapeutic regimen Antihypertensive drugs and side effects

If pain returns or symptoms progress, instruct patient to seek immediate help


Following an aortic aneurysm repair, the patient suddenly develops severe pain in the right lower extremity. The right pedal pulse is decreased, and the right foot is cool and pale. Which complication should the nurse suspect?

a. Hypothermia

b. A wound infection

c. Bleeding from the graft site

d. An embolization or graft occlusion

Audience Response Question


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Disorders of the Aorta