04/11/2024 Flashcards
What are the 2 types of AAA true aneurysms and which is more likely to rupture?
Saccular - more likely to rupture
Fusiform
Pathophysiology of AAA?
Weakening of the Aortic Wall over time due to age, high blood pressure, or genetic factors. Conditions like atherosclerosis further damage the wall, making it prone to dilation.
Chronic inflammation and an increase in enzymes that break down structural proteins (like elastin and collagen) within the aortic wall contribute to this weakening.
As the wall weakens, the aorta starts to bulge out due to the constant pressure of blood flowing through it.
With each heartbeat, the pressure on this weakened area causes it to enlarge progressively, forming an aneurysm.
If the aneurysm continues to grow, the aortic wall may become too thin to handle the pressure, leading to a rupture.
Triad of AAA?
Hypotension
Tearing back or abdominal pain
Painful pulsatile mass
Investigations for AAA?
US is first line
CT angiography for detailed assessment, especially for pre-surgery
In haemodynamically unstable patients the diagnosis is clinical, these patients are not stable enough for a CT scan etc to confirm the diagnosis and should be taken straight to theatre.
What is the mortality rate of a ruptured AAA?
80%
Management of asymptomatic AAA?
Rusk factors - statins, aspriin 75mg OD, antihypertensives, stop smoking & screening
Surgery - open surgical repair or EVARif more comobidities, women or men >70
If a pt has an AAA found at 4.7cm how often do they need to be screened?
3 monthly
What is a small, medium and large AAA?
3-4.4cm = small
4.5-5.4cm = medium
>=5.5cm = large
What are the 2 different types of surgery for AAA?
Open surgical repair - large laparotomy, clam aorta, remove aneurysm all segment and replace it with a synthetic graft.
EVAR - stent graft is inserted through femoral arteries and places within the aneurysm to reinforce the aortic wall
OSR vs EVAR for AAA?
OSR has good long term durability, is good for younger pts or those with complex anatomy
More invasive, longer recovery time and higher postoperative risk
EVAR requires lifelong surveillance due to potential for endoleak. It’s also not suitable for all anatomies.
What can trigger Raynaud’s disease?
Cold temperature or emotional stress
Pathophysiology of raynayds disease?
Excessive arterial vasoconstriction in response to cold temperatures or stress
What can cause raynaud syndrome i..e secondary raynaud phenomenon?
Vasospasms due to arteriolar changes in fingers which may be precipitated by the following:
Drugs - oral contraceptives
Cervical rib
leukaemia
type I cryoglobulinaemia, cold agglutinins
Smoking
Ioccupation trauma e.g. handling vibrating tools
Hyperviscocity
CTD e.g. scleroderma, SLE, sjogrens etc
Arterial disease
Neurological diseases e.g. carpal tunnel syndrome
Which area of the hand is typically spared in primary raynauds diseases but not in secondary?
The thumb!
Due to it having better blood flow
Clinical presentation of raynauds?
Finger & toes B/L
White -> blue -> red
Livedo reticularis may occur during episodes
Rewarming is associated with transient numbness, pain or paraesthesia in the affected areas
In primary you may get Sx of systemic vasospasm e.g. migraine or IBS
In secondary you may get pain, ulceration or necrosis due to critical ischaemic, signs of associated systemic disease.
Managament of raynauds?
Prevent cold to hands/feet & stress management & minimise vibration exposure & smoking cessation & discontinue causative drugs
Nifedipine or other CCB
If severe or complicated pt may be admitted and given IV prostcyclin infusions: effects may last several weeks/months e.g. iloprost
Pathophysiology of hammer toes and claw toes in diabetic foot disease?
Muscle wasting of the intrinsic pedal muscles leads to overpowering of the spared extrinsic muscles = Thickening of plantar aponeurosis = sole of foto contracts
Triad of Leriche syndrome?
Absent femoral pulses
Impotence
Claudication
What ABPI suggests critical limb ischaemic?
<0.5
Trophic changes from peripheral arterial disease?
Hair absent
Thickened nails
Dry scaly skin
Shiny skin
Imaging for PAD
ABPI (if too high due to calcification then toe brachial index may be done)
Handheld Doppler is the best initiat test for detecting blood flow if acute limb ischaemia
CT angiography with contrast to look for thr site of stenosis or occlusion
What options for surgery are there for PAD/
Endovascular revascularisation- percutaneous transluminal angioplasty +/- stent placement or atherectomy
Peripheral artery bypass surgery or endarterectomy (opening vein up ans scraping off plaque)
Wet vs dry gangrene
dry gangrene – where the blood flow to an area of the body becomes blocked - chronic
wet gangrene – caused by a combination of an injury and bacterial infection - more of an emergency in terms of vascular surgeons as will spread quickly!!
What is autonomic dysreflexia?
A clinical syndrome that occurs in pts who have had a spinal cord injury at or above level of T6
This causes a sympathetic spinal reflex via thoracolumbar outflow and the usual parasympathetic response is prevented by the cord lesion = imbalanced sympathetic response causing extreme hypertension, flushing and sweating above the level of the cord lesion
