Vascular surgery Flashcards
Causes of acute arterial occlusion or insufficiency
Pro embolic states - Cardiac arrhythmias, endocarditis, aneurysms
Hyper coagulable states - Congenital clotting disorder e.g. antithrombin deficiency, protein C def or factor V Leiden, prothrombin or hyperhomocysteinemia. Acquired eg immobility, cancer, pregnancy, anti phospholipid syndrome, inflammatory disorders
Presentation of Acute arterial occlusion or insufficiency
6 P
Pain, Pallor, parenthesis, Paralysis/reduced power (impending gangrene), Polar/poikilothermia (Cold), pulselessness.
Graded by sensory and motor defects
Grade 1: Viable, Non sensory or motor deficit = no immediate threat
Grade 2: Marginally threatened, Minimal sensory eg toes deficit, no motor = Salvaeable if promptly treated
Grade 3: Immediately threatened, More than toes sensory loss and mild to moderate motor loss = Salvageable if promptly revascularised
Grade 4: Irreversible , Profound sensory and motor loss egnumb and paralysis = major tissue loss, amputation, permanent nerve damage inevitable
Differentiate Embolus to thrombus
Embolus - acute, prominent loss of S and M, No Hx of claudication or atrophic changes and normal collaterals pulses.
Thrombus - Progressive or acute on chronic onset, Less profound S and M loss, may have Hx of claudication or atrophic changes. Contralateral limb pulse reduce or absent.
Ix for acute arterial occlusion
Hx and Ex - if immediately threaten go to surgery
ABI
ECG and troponin - rule out MI or arrhythmia
FBC - leukocytosis, thrombocytosis, reduced PLT.
PR/INR - check pt anticoagulant therapy
Echo - source - wall motion abnormalities, thrombus, valvular disease, aortic Disection type A
CT - Underlying atherosclerosis, aneurysm,aortic dissection
Conventional catheter based angiography in OR or prelude to thrombocytosis
Tx for Acute arterial occlusion
Heparin
Emergent revascularisation if impaired neurovascular status.
If not neurovascular impaired then work up including angiogram
Definitive Tx
- embolus - embolectomy
- Thrombus - Thrombectomy may need bypass graft or endovascular therapy
- If irreversible ischemia (no M Ro S, Absent V and A dopplers and rigor - amputation
Tx underlying cause
Post operative - Heparin and may need warfarin depending on underlying cause
Cx of acute arterial occlusion
Compartment syndrome with prolonged ischemia - 4 compartment fasciotomy
Risk of arrhythmia and depth with reperfusion injury
Renal failure and multi organ failure due to toxic metabolites
12-15% mortality rate
5-40% morbidity rate - amputation.
DDX for claudication
Vascular - atherosclerotic disease, Vasculitis eg Buerger’s disease, Diabetic neuropathy, Venous disease eg DVT or varicose veins, Popliteal entrapment syndrome eg baker’s cyst
Neurological - Neurospinal disease eg spinal stenosis, Reflex sympathetic dystrophy.
MSK - osteoarthritis, rheumatoid arthritis, CT disease, remote trauma
How to differentiate vascular and neurogenic claudication
Vascular
Releived when stop walking, worse when walking uphill, pulses and ABIs reduced, Pain on cycling, no motor weakness after walking, and skin changes present.
Neurogenic
Improved on bending over or sitting, worsen when walking down hill, Pulses and ABI is normal, no pain on cycling, Motor weakness after walking, Skin changes absent.
Commonest cause of Chronic artery occlusion
Atherosclerosis in lower limb
Risk factors for Chronic artery occlusion
Major ones are smoking and DM
Minor - HTN, Hyperlipideamia, FMHx, Obesity, sedentary lifestyles, PMHX or FmHx CAD/CVD
Signs and symptoms of chronic artery occlusion
Claudication - on exertion, relieved by rest and no postural changes necessary. Reproducible over same distance in same spot and received by same rest.
Critical if pain at rest, or night or tissue loss eg ulcers or gangrene.Pain on forefoot and improved by hanging foot off bed. ABI less than 0.40
Pulses may be absent, may have Bruins
Signs of poor perfusion - hair loss, hypertrophic nails, atrophic muscle, skin ulceration and infection, slow CRT, Prolonged pallor with elevation and rub or on dependency, venous trough get
Other signs of atherosclerosis - CVD, CAD, impotence, splanchnic ischemia
Ix for chronic artery occlusion
Bloods - FBC, Fasting lipid, U and E, Coags,
ABI - less then 0.9 abnormal. Rest pain is at 0.3
CTA and MRA
Arteriography
Tx for Chronic artery occlusion
Conservative - risk factor modification - stop smoking, sugar, BP, and lipid control, antiplt. Exercise. Foot care
Meds - Anti PLT, clostazol (cAMP phosphodiesterase)
Surgery
- Indicated if severe lifestyle impairment or critical ischemia
- Endovascular - stunting or angioplasty
- Endarterectomy - removal plaque and repair with patch
- Bypass graft sites -
- Chemical Sympathectomy - vasodilation
- Amputation - when not suitable for revascularisation or persistent serious infection/gangrene
What is an Aortic dissection
Tear in aortic intima allowing blood to dissect into the media
Type A involves the ascending aorta
Type B only descending aorta
Acute less then 2 was
Cause of aortic dissection
Most common - HTN causing degenerative and cystic changes to damage aortic media Other CT disease eg Marfan's or Ehler's Caustic medial necrosis Atherosclerosis Congenital conditions eg coarctation Infections eg syphilis Trauma Arteritis eg Takayasu's
Who get aortic dissection
Males more then femal
African Americans more then Asians
50-65 yr old or 20-40 if CT disease
Presentation of Aortic dissection
Sudden onset tearing chest pain that radiates to back
Hx of HTN, ischemia syndromes to to occulsions eg MI, Ischemic stroke, Horner syndrome, Mesenteric ischemia, AKI, Peripheral ischemia
Rupture into pleura - dyspnea or hemoptysis. Peritoneum - hypotension and shock. Or Pericardium - Cardiac tamponade
Syncope
Ex - asymmetric BP and pulses, new diastolic murmur caused by unseating of aortic valve cups in a type A dissection
