Surgery/AH2 Flashcards
(217 cards)
AAA-definition
Abdominal aortic aneurysm (AAA) is a focal dilatation of the abdominal aorta to more than 1.5 times its normal diameter.
State some risk factors for AAA-major ones are
Advanced age Smoking (most important risk factor) Atherosclerosis Hypercholesterolemia and arterial hypertension Positive family history Trauma
Best initial test to diagnose USS
abdominal ultrasound is the best initial and confirmatory test to diagnose AAAs and determine their extent.
Where is the most common location for AAA to occur at
Below the renal arteries- Infrarenal
Because there is less collagen in this area
Why do you get autonomic symptoms- sweating and feeling calmy after rupture of AAA
Since the celiac, sup., and inf. ganglia runs throughout the AA, a bulging aneurysm or a ruptured aneurysm causing a bleed into the peritoneal space (ant or post) will result in compression of said ganglia leading to sympathomimetic symptoms, like sweating, anxiety, anorexia, constipation.
Classic triad for ruptured AAA
- Hypotension/collapse
- Back/abdominal pain
- Palpable, pulsatile abdominal mass (caution
in patients with raised BMI)
State some investigations you would want to order and the reason for it
- bloodwork: CBC, electrolytes, urea, creatinine, PTT, INR, type and cross
- abdominal U/S- screening and surveillance
- CT with contrast(accurate visualization, size determination, EVARplanning)
- peripheral arterial doppler/duplex (rule out aneurysms elsewhere, e.g. popliteal)
What is the medical management of AAA which is less than 5.5cm- 4 things
Smoking cessation (reduces rate of expansion and risk of rupture)
Improve blood pressure control
Commence statin and aspirin therapy
Weight loss and increased exercise
What are the indications for surgery in AAA-4 things
- Surgery should be considered for an AAA >5.5cm in diameter,
- AAA expanding at >1cm/year
- symptomatic AAA in a patient who is otherwise fit.
- Rupture
What are the mainstay treatment options for AAA repair
Open repair involves a midline laparotomy or long transverse incision, exposing the aorta, and clamping the aorta proximally and the iliac arteries distally, before the segment is then removed and replaced with a prosthetic graft
The endovascular repair involves introducing a graft via the femoral arteries and fixing the stent across the aneurysm –> EVAR(remember the complication is endoleaks)
The patient has a ruptured AAA, if the patient is stable vs unstable what do you do
If the patient is unstable, they will require immediate transfer to theatre for open surgical repair
If the patient is stable, they will require a CT angiogram to determine whether the aneurysm is suitable for endovascular repair*
However
Treatment: open emergency surgery (gold standard) or endoscopic treatment
What are some of the physical signs you may see in a pt. with a ruptured AAA which is contained
Throbbing abdominal or low back pain radiating to the flank, buttocks, legs, or groin Grey turner sign (ecchymosis of the affected flank area) Cullen sign (periumbilical ecchymosis)
Definition of a dissection
Dissections are a separation of the arterial wall layers caused by blood entering the intima-media space after a tear in the internal layer occurred.
What are the characteristic clinical features in an aortic dissection
- Sudden and severe tearing/ripping pain in the anterior chest, interscapular area, the neck, jaw or abdomen depending on the site of dissection
- Syncope
- Asymmetrical pulse and BP readings
What is the treatment for aortic dissection
A- needs help
B- conservative
Open or endovascular stent grafting repair (Stanford A dissections, which involve the ascending aorta, require immediate surgery)
Control hypertension (Stanford B dissections, which do not involve the ascending aorta, are generally treated conservatively)
STI and Aneurysm connection
Tertiary syphilis (due to obliterative endarteritis of the vasa vasorum)
CXR of an aortic dissection will show
widened mediastinum
What some causes of aortic dissection
- HTN
- Trauma
- Syphilis
- Connective tissue disease
- Use of amphetamines and cocaine
- Atherosclerosis
Location of aortic dissection, and its classification
Standford classification
Stanford A = Affects ascending aorta
Stanford B = Begins beyond brachiocephalic vessels.
6Ps of acute limb ischemia
6 Ps – all may not be present
Pain: absent in 20% of cases
Pallor: within a few hours becomes mottled cyanosis
Paresthesia: light touch lost first then sensory modalities
Paralysis/Power loss: most important, heralds impending gangrene
Polar/Poikilothermia/ Perishing cold’ Pulselessness: not re iable
What are the difference between embolus and thrombus causing acute limb ischemia
The embolus is an acute onset compared to the thrombus- which is chronic- hence there can be hx of claudication and thrombosis
examples of conditions that predispose to embolism are: arrhythmias, endocarditis, and arterial
aneurysms
existing atherosclerotic plaques (i.e. chronic PAD) can rupture causing thrombosis
Leriche syndrome (aortoiliac occlusive disease)-triad is
Pain in both legs and the buttocks
Bilaterally absent femoral, popliteal, and ankle pulses
Erectile dysfunction
Shock
What is the initial test for ALI and then diagnostic test,
what other tests can be done
Best initial test: arterial and venous Doppler
Diminished or absent Doppler flow signal distal to site of occlusion.
Confirmatory test: angiography (DSA, CTA, MRA)
Digital subtraction angiography (DSA) is the imaging modality of choice.
Should only be performed if delaying treatment for further imaging does not threaten the extremity
-can consider ECHO if embolic
Acute limb ischemia due to thromboembolism- treatment
- Leg is viable
- Emergency
- Leg is unviable
Acute limb ischaemia is a surgical emergency. Complete arterial occlusion will lead to irreversible tissue damage within 6 hours. Early senior surgical support is vital.
Start the patient on high-flow oxygen and ensure adequate IV access. A therapeutic dose heparin or preferably a bolus dose then heparin infusion should be initiated as soon as is practical.
Systemic anticoagulation with an IV heparin bolus followed by continuous infusion unless a contraindication is present
Viable, non-threatened limb
Urgent angiography to localize the site of the occlusion
Revascularization procedure (open or catheter-directed thrombectomy or thrombolysis) within 6–24 hours
Threatened limb: emergent revascularization procedure within 6 hours
Non-viable limb: limb amputation
Acute limb ischemia due to compartment syndrome: fasciotomy (see compartment syndrome)
Acute limb ischemia due to a dissecting aneurysm: stenting and/or surgical repair