Aortic Aneurysm Flashcards
Aortic Aneurysms
- what are they?
A permanent, localized outpouching, or dilation of vessel wall (congenital or acquired)
May involve aortic arch, thoracic aorta, abdominal aorta or a combination
- most are abdominal aorta below renal arteries
- 75% occur in abdomen; 25% in thoracic aorta
Dilated aortic wall becomes lined with…
thrombi
Primary Cause of Aortic Aneurysm (5)
- Degenerative
- Congenital (Ehlers Denholm syndrome, marfan syndrome - breakdown of elastic tissue)
- Mechanical (blunt force trauma)
- Inflammatory (giant cell arteritis)
- Infections (HIV, syphilis, artherosclerotic plaque)
Classification
Aneurysms are classified as TRUE or FALSE
True Aneurysm
The wall of the artery forms the aneurysm, and at lease one vessel layer is intact
True aneurysm subdivides into
1. fusiform aneurysm
2. Saccular aneurysm
False Aneurysm (pseudoaneurysm)
- not an aneurysm but a disruption of all layers of arterial wall -> results in bleeding that is contained
- may result from trauma or infection, or at the site of peripheral artery bypass surgery
Fusiform is common in…
Saccular is seen where?
a) the abdominal aortic area
b) in the brain
Clinical manifestation of thoracic aneurysm
often aortic aneurysms are asymptomatic but if symptoms are present:
thoracic: deep diffuse chest pain extending to interscapular area
Clinical Manifestations of Ascending aorta & aortic arch aneurysm (5)
hoarseness, coughing, SOB d/t pressure on laryngeal nerve, angina, TIA
Clinical Manifestations of Abdominal Aortic Aneurysm (2)
Often asymptomatic, detected on routine physical exam
- pulsatile mass in periumbilical area slightly left of the midline
- back pain caused by compression on lumbar nerve & epigastric discomfort
Complications of Aortic Aneurysm (3)
Most serious: rupture of aneurysm (EMERGENCY SITUATION)
Flank ecchymosis (Grey TUrner’s sign - discoloration in the lateral flank.)
Cullens sign - superficial edema and bruising in the periumbilical area
Appear 24-48 hours after the onset of retroperitoneal bleeding
If ruptured blood leaks into thoracic or abdominal cavity, 90% mortality from hemorrhage
Treatment of AA: Goal
to prevent aneurysm rupture and extension of dissection
Treatment of AA: Conservative therapy
- for small asymptomatic AAAs (4.0-5.5cm)
- size of aneurysm will determine the risk of rupture
- quit smoking, treat HTN, ultrasound surveillance every 6 months with referral to surgery if the diameter reaches 5.5 cm or grows more than a cm in a year.
Treatment of AA: Surgery is for… (4)
rapid expanding aneurysm (> 1cm diameter increase/year)
When pt becomes symptomatic
High risk of rupture
Involves replacing abdominal aneurysm with a synthetic tube graft
Elective Surgery for AA: During Pre-op
Hydration
Correction of electrolytes, coagulation, hematocrit abnormalities (pts with low hematocrit have higher blood loss and need fluid and blood replacement)
Bowel prep
Elective Surgery for AA: Procedure (5)
- Incision of diseased aortic segment
- Removal of thrombus or plaque
- Deployment & suturing of synthetic graft
- Most resections done in 30-45 min
- Requires cross-clamp clamping distal to aneurysm
Emergency Surgery for AA
Ruptured aneurysm -> 100% fatality without emergency surgery
Only minimal physical preparation is possible
Reassurance and emotional support for pt and family
Lethal complication in repair of ruptured AAA = intra-abdominal hypertension with associated compartmental syndrome
- Decrease HTN - intra-abdominal htn reduces blood flow to the viscera and causes decreased perfusion to the organs and can cause multisystem organ failure
Post-Op Care Abdominal Aortic Aneurysm(6)
- Typically admits to ICU post-op for 24-48 hours
- ECG, ET tube, art line, CVP or PA catheter, peripheral IVs, foley catheter, chest tubes (if thorax opened in surgery), possibly an NG
- Pain meds: either epidural catheter or PCA
- Maintain adequate respiratory function, fluid & electrolyte balance
- Assess graft patency
- Monitor renal perfusion
Graft Patency
Adequate BP important: prolonged hypotension results in graft thrombosis
- determine adequate blood flow by looking at urine output, MAP, and extremities
- severe hypertension may cause undue stress on anastomosis sites and they could burst
- MAP should be greater than 60 or greater than or equal to 65. shows organ perfusion
- IV diuretics and dysrhythmias
CVS (7)
continuous ECG monitoring
- myocardial ischemia or MI during peri-op due to decreased myocardial O2 supply or increased demand
- dysrhythmias r/t electrolyte imbalance, hypoxemia, hypothermia or myocardial ischemia
Electrolyte and ABG monitoring
Admin O2
Adequate pain control
Resume cardiac meds
Infection post-op AA
Vascular graft infection
- admin broad spectrum antibiotic per order
Assess for fever, increased WBC, redness, swelling, drainage
Assess surgical site for infection
Also, examine all IV sites
- foley cath insertion site
Post-op GI
After abdominal aortic surgery, paralytic ileus is possible d/t anaesthesia & manipulation of bowel
- intestines become swollen & bruised paused peristalsis
- NG prevent aspiration of stomach contents - low intermitted suction to decompress the bowel
- Return of bowel function. Listen to the bowel sounds, passing flatus, paralytic ileus rarely lasts past POD4
CNS
Assess LOC
Glasgow coma scale
With involvement of descending aorta, neurovascular assessment of lower extremities is important
Peripheral Perfusion Status
- check all peripheral pulses q1h for several hrs (per protocol) and then per routine
- if surgery involves ascending aorta & aortic arch -> emphasis is to assess carotid, radial and temporal pulses
- If surgery involves descending aorta - assess femoral, popliteal, posterior tibial and dorsalis pedis pulses
- mark pulse locations with a felt-tip pen
Renal
Foley cath
immediate post-op: record u/o q1h maintain 0.5-1 ml/kg/hr
I&O daily weight until resumes regular diet
Monitor lab work for renal function (BUN, Creatinine, eGFR)
Factors for decreased renal perfusion
Embolization to renal artery(ies)
Individuals at high risk for renal failure include patients with hypotension, prolonged clamping during surgery, preexisting renal disease or diabetes (have to clamp under the aorta distal to it)
