Arterial Flashcards
Features of chronic lower limb arterial stenosis or
occlusion
● Intermittent claudication
● Rest pain
● Dependent rubor or sunset foot
● Ulceration
● Gangrene
● Arterial pulsation diminished or absent
● Arterial bruit
● Slow capillary refilling
Intermittent claudication
Reliably brought on by walking
Not present on fist step (unlike osteoarthritis)
Reliably relieved by rest, standing or sitting within 5 minutes
-lumbar vertebral disc pain or spinal stenosis usually only relieved by sitting and takes >5 minutes
Claudication distance varies little day-to-day
-unlike musculoskeletal pain
Claudication distance is decreased by increasing the work demands and hence oxygen requirements of the muscles affected, e.g. walking up hill, increasing the speed of walking and/or carrying heavy weights,
Most common site of stenosis
Superficial femoral artery disease (70%)
-hence majority of caludicants have calf pain
Aorto-iliac disease (30%)
Leriche’s syndrome
Aorto-iliac disease causing buttock claudication in association with sexual impotence
Rest pain
=anaerobic respiration at rest
=Critical limb ischaemia
Classically improved with standing
Worse when lying flat or limb elevation
Ulceration in CLI
painful erosion between toes or as shallow,
non-healing ulcers on the dorsum of the feet, on the shins and especially around the malleoli
Colour of chronic limb ischaemia
- Chronically ischaemic limb tends to equilibrate with the temperature of its surroundings
- May feel quite warm under the bedclothes.
-Does not produce paralysis and sensation is usually
intact
-Patients with their leg in dependence may have a red swollen foot that may be mistaken for cellulitis by
the unwary clinician.
However, elevation of the limb reveals the severity of the ischaemia, with venous guttering and foot pallor that changes to a red/purple colour when the limb is allowed to hang down again (dependent rubor or the sunset
foot sign)
Arterial bruit
=stenosis
Machinery murmur
= AV fistula
Loss of pulse on exercise
Indicated pulsation from collaterals around an occlusion
As vasodilation occurs below the occlusion and claudication occurs there is a loss of pulse pressure across the collaterals and a loss of pulse
Signs and symptoms of aortoiliac disease
- Claudication in buttocks, thighs and calves]=
- Femoral and distal pulses absent in both limbs
- Bruit over aortoiliac region
- Impotence (Leriche)
Signs and symptoms of iliac obstruction
- Unilateral claudication in the thigh and calf and sometimes the buttock
- Bruit over the iliac region
- Unilateral absence of femoral and distal pulses
Signs and symptoms of femoropopliteal obstruction
-Unilateral claudication in the calf
-Femoral pulse palpable with absent unilateral
distal pulses
Signs and symptoms of distal obstruction
- Femoral and popliteal pulses palpable
- Ankle pulses absent
- Claudication in calf and foot
Ankle-brachial pressure index
ABPI
Ratio of systolic pressure at the ankle to that of the ipsilateral arm
Highest pressure in the doralis pedis, posterior tibial or peroneal artery = numerator
Pressure in brachial = denominator
ABPI values
- 9 - 1.3 = normal
- 5 - 0.9 = intermittent claudication
- 3 - 0.5 = rest pain
<0.3 = imminent necrosis
> 20% drop post exercise = flow-limiting arterial disease
Duplex
Uses b-mode ultrasound and doppler
Cost-effective and non-invasive and in experienced hands as good as angiography
Relatively poor at visualising aortoiliac vessels, particularly in obese patients
High flow= stenosis
Digital subtract percutaneous angiography
DSA
-injection of radio-opaque contrast dye into the arterial tree by percutaneous catheter method e,g, seldinger cannulation
Images are obtained and digitalised by computer, removing the extraneous background tissues
Advantages:
- Provides dynamic arterial flow information
- Allows endovascular intervention
Disadvantages:
- Bleeding
- Haematoma
- False anuerysm
- Arterial dissection
- Thrombosis
- Renal injury
Non-surgical management of arterial stenosis
- Structured exercise programme of 2 hours per week for >3 months
- Smoking cessation
- Weight loss if obese
- Optimise medical coniditions
- -Diabetes: metformin
- -Hypertension: ACE-inhibitors
Atrovastatin (protective independent of serum cholesterol)
Clopidogrel
Complications of angioplasty
Occurs in ~5%
Haematoma
False aneurysm
Distal embolisation
Thrombosis
Hamper subsequent arterial bypass attempts
Miller cuff
Vein cuff for PTFE graft at distal anatsomosis
Approach for aortobifem bypass
Midline approach
-Transverse would divide inferior epigastric artery which are important collaterals in aortic occlusive disease
Subclavian steal syndrome
In periods of arm activity, reversal of the blood supply to the posterior cerebral circulation via the vertebral artery can result in a wide range of cerebral symptoms, including vertigo, diplopia, dysphagia, dysarthria, visual loss, or syncope
Proximal subclavian stenosis means that during upper limb exercise, there is reversal of flow from vertebral artery to supply upper limb
–> cerebral ischaemia
Caused by:
- Atherosclerosis
- Vasculitis
- Thoracic outlet syndrome (e.g. cervical rib)
- Complications following aortic coarctation repair
Coronary-Subclavian Steal Syndrome
Coronary-Subclavian Steal Syndrome occurs in patients who have undergone an Internal Mammary Artery (IMA) Graft. An increase in oxygen demand in the left arm then steals blood from the IMA leading to cardiac ischaemia.
Gangrene
Gangrene refers to death of macroscopic portions of tissue, which turns black because of the breakdown of haemoglobin and the formation of iron sulphide
Definition of acute limb ischaemia
Embolic arterial occlusion causing limb-threatening ischaemia requiring urgent intervention
6 Ps of acute limb ischaemia
Pain
Pallor
Paralysis
Pulsessness
Paraesthesia (actually anaesthesia)
Poikilothermia (Perishingly cold)
Treatment of acute limb ischaemia
1) 5000 units of IV heparin
- prevent elongation of clot (particularly distal)
2) Analgesia for pain
3) Embolectomy
- Expose vesssel
- Transverse incision proximal to occlusion
- Fogarty catheter to remove embolism
- DSA to demonstrate flow
4) Post-op heparin infusion
- Warfarin bridging
Considerations for thrombolysis
Acute limb ischaemia in which the occlusion is not causing severe ischaemia
Thrombolysis will take up to 24 hours to achieve clot breakdown
Consists of intra-arterial injection of tissue plasminogen activator
Contraindications: recent stroke, pregnancy, bleeding diathesis, poor outcomes in patients over 80 years old
Broad treatment for acute mesenteric ischaemia
1) resection of infracted bowel
2) embolectomy of arterial bypass
3) re-look lap at 24 hours +/- further resection
Sources of emboli
Cardiac
- AF
- Left ventricular mural thrombus post MI
- Vegetation from infective endocarditis
Aneurysms
-Trash foot
Atherosclerotic plaques
- thrombosis at site
- emboli from site
Parasitic
Mycotic
Air
- central venous access
- head and neck injury / surgery
Fat
- trauma
- intramedullary nailing / fracture fixation
Indications for amputation
Dead limb
● Gangrene
Deadly limb ● Wet gangrene ● Spreading cellulitis ● Arteriovenous fistula ● Other (e.g. malignancy)
‘Dead loss’ limb
● Severe rest pain with unreconstructable critical leg ischaemia
● Paralysis
● Other (e.g. contracture, trauma)
Long posterior flap
Oldest of the below-knee approaches
- Popular as relatively simple
- Tibial tuberosity identified and a distance 10 cm measured distally and marked with a sterile marker pen; this is the anterior landmark
- Circumference is measured at this landmark with a long suture tie and this length divided into two thirds
- The suture is centred over the anterior landmark so that there is one-third either side. = posterior limit of transverse incision
Indications for repair of abdominal aortic aneurysm
Symptomatic
Asymptomatic and 5.5 cm or larger
Asymptomatic, larger than 4.0 cm and has grown by more than 1 cm in 1 year.
Monitoring abdominal aneurysm growth
> 5.5cm: 2ww referral to vascular centre
3 - 5.4cm: 12 ww to vascular centre
- 0 - 4.4cm: scan every 2 years
- 4 - 5.4cm: scan every 3 months
Risk factors for abdominal aortic aneurysm
COPD
PAD/ CVD
European
FHx
HTN
Increased cholesterol
Smoking
Definition of aneurysm
Vessel more than 50% increase in size
Dilatation of localised segments of the arterial system of increased by 50% of original size
Ectatic vessels
Dilatation of vessels but <50% increase
Location of abdominal aortic aneurysms
95% are infra-renal
Complications of amputation
Immediate
-Haemorrhage
Early
- Haematoma
- Infection (gas gangrene secondary to faecal contamination in above-knee)
- Wound dehiscence
- Gangrene of flaps
- DVT, PE
Late
- Pain
- -unresolved infection such as sinus, osteitis,
- -bone spur
- Phantom limb pain (give amitriptyline and gabapentin)
- Ulceration of the stump
Management of ruptured abdominal aortic aneurysm
● Early diagnosis (abdominal/back pain, pulsatile mass, shock)
● Immediate resuscitation (oxygen, intravenous replacement therapy, central line)
● Maintain systolic pressure, but not >100 mmHg, consider permissive hypotension
● Urinary catheter
● Cross-match 6 units of blood
● Rapid transfer to the operating room
Complications of AAA repair
Cardiac
- ischameia
- infraction
Respiratory
- atelectasis
- HAP
Colonic ischaemia
-~10%, usually resolved without intervention
Renal failure
Neurological
-spinal cord ischaemia
impotence
Aortoduodenal fistula
-think if meleana or haematemesis in months/years post AAA repair
Prosthetic graft infection
Buerger’s disease
Thromboangiitis obliterans
Consists of occlusive disease of small and medium sized arteries, thrombophlebitis of superficial veins, and raynaud’s syndrome
-e.g. plantar, tibial, radial
Often only one or two of the features present
Occurs in male smokers, <30 years
Smoking cessation halts progression but does not reverse damage
Cystic myxomatous degeneration
Jelly-like cystic material around arteries such as politeal
Causes claudication from compression
Treatment is by removal of material +/- resection of artery and bypass
Acrocyanosis
Often confused with Raynaud’s
Young female patients with chillblains and dusky hand
Not episodic, not painful
