Vascular Surgery Flashcards
Aetiology of acute limb ischameia?
- Acute embolic ischameia: an embolus occluded a healthy arterial tree
- Acute traumatic ischaemia
- Acute thrombotic ischaemia: atherosclerosis and sluggish blood flow could cause thrombus formation
What is Claudication
Claudication is pain in the legs or arms that comes on with walking or using the arms. This is caused by too little blood flow to your legs or arms. Claudication is usually a symptom of peripheral artery disease, in which the arteries that supply blood to your limbs are narrowed, usually because of ATHEROSCLEROSIS
Risk factors of embolic ischaemia?
MI
Atrial fibrillation
Prosthetic valve replacement
What are the 6P’s of acute ischaemia?
Pain Paraesthesia Pale Pulseless Paralysis Piokilothermia (inability to regulate core body temperature )
What is the first line investigation in acute ischaemia and why?
DUPLEX. BEDSIDE. NON INVASIVE. NO CONTRAST NEEDED.
Pros and cons of MRA in acute ischaemia?
PROS: Less nephrotoxic and no radiation
COMS: more expensive and time consuming
Management of a patient with acute limb ischameia?
- IMMEDIATE IV Heparin (anticoagulant) to prevent clot propagation
- Analgesia
- Revascularization methods or improve existing perfusion
Management of a patient with acute limb ischameia?
- IMMEDIATE IV Heparin (anticoagulant) to prevent clot propagation
- Analgesia
- Revascularization methods or improve existing perfusion
Explain and reperfusion injury (one of the the two main complications of intervention after acute limb ischaemia)
Ischaemia-Reperfusion injury is defined as the paradoxical (self contradictory) exacerbation of cellular dysfunction and death, following restoration of blood flow to previously ischaemic tissues. Reestablishment of blood flow is essential to salvage ischaemic tissues. However reperfusion itself paradoxically causes further damage, threatening function and viability of the organ. IRI occurs in a wide range of organs including the heart, lung, kidney, gut, skeletal muscle and brain and may involve not only the ischaemic organ itself but may also induce systemic damage to distant organs, potentially leading to multi-system organ failure. Reperfusion injury is a multi-factorial process resulting in extensive tissue destruction.
Explain compartment syndrome (one of the the two main complications of intervention after acute limb ischaemia)
Muscle swelling due to reperfusion after ischaemia. The swollen muscles are compressed within the fixes fascial compartments, compressing the blood vessels which may lead to ischaemia itself. The pressure could also cause local nerve damage.
What is the treatment of compartment syndrome
The treatment is urgent fasciotomy to release the compression. The usual site for fasciotomy is the calf
Management of acute limb ischaemia?
If due to an Embolus: fogarty embolectomy
If due to thrombosis:
- thrombolysis of focal lesion
- bypass surgery if it is an extensive lesion
What is a bypass surgery
Coronary artery bypass surgery is also called bypass surgery or open heart surgery. It is done to allow blood to flow around blocked blood vessels in the heart. Coronary arteries are the blood vessels that supply the heart muscle with oxygen and nutrients. During bypass surgery, a piece of a blood vessel from the leg, arm or chest, called a graft, is removed and attached to the aorta and around the blocked blood vessel of the heart. The blocked blood vessel remains, but blood is carried around it in the new blood vessel. If there are several blocked vessels, you may have more than one bypass done.
Main cause of chronic ischaemia?
Above 45: Atherosclerotic changes.
Below 45:
-in DM patients: presenile atherosclerosis
-in non DM patients: buerger’s disease of raynaud’s disease
Main cause of chronic ischaemia?
Above 45: Atherosclerotic changes.
Below 45:
-in DM patients: presenile atherosclerosis
-in non DM patients: buerger’s disease, Raynaud’s disease, arteries
Clinical presentation of DVT?
UNILATERAL: Redness Hotness Tenderness Oedema Swelling Pain
Do DVT patients have pitting or non pitting oedema?
PITTING
What is the score used to predict likelihood of DVT?
Well’s score.
-2 to 0: unlikely
1 to 2: moderate probabity
3-8: high probability
What do we give -2 for on the well’s score?
Any other diagnosis just as likely as DVT
Imaging of choice for DVT?
Duplex ultrasound with compression.
Other imaging choices for DVT?
Contrast venography - previous gold standard but invasive and expensive (x ray with continuous contrast infusion)
CT venography - can be used to diagnose inferior vena cava and iliac vein thrombosis, as well as thrombosis of the common, deep and superficial femoral veins
DVT Treatment and management:
- LMWH Heparin for at least 5 days + warfarin.
Stop LMWH after INR: 2-3 for 2 consecutive days
Stopping warfarin depends on the group:
-PRVOKED DVT: lifelong anticoagulan
(Pregnancy, cast, contraceptives) from 3 to 6 months
ACTIVE CANCER: 6 months of LMWH
-Unprovked DVT:
Warfarin for you to6 months, lifelong warfarin should be considered. - Compression stockings ( however contraindicated in patients with PAD) and early mobilization to avoid post thrombotic syndrome.
Describe post thrombotic syndrome
Occurring after DVT due to improper canalization and valve damage. Limb swelling, hardening, pain, pigmentation and ulceration, lipodermatoscelorsis, venous eczema (redness and itching)
Presentation of pulmonary embolism? TRIAD
- Pleuritic Chest pain ( sudden and intense sharp, stabbing, or burning pain in the chest when inhaling and exhaling. It is exacerbated by deep breathing, coughing, sneezing, or laughing.)
- Shortness of breath/ rapid breathing(dyspnea/ Tachypnea)
- Hemoptysis (massive attack)
What are the 3 risk groups of PE?
1.High risk PE (massive PE) –
PE so severe as to cause circulatory collapse due to acute right heart failure
(i.e. systolic BP <90mmHg or BP drop ≥40mmHg for more than 15 minutes that is not caused by a cardiac arrhythmia, hypovolaemia or sepsis).
- Intermediate risk PE (submassive PE) – the patient is haemodynamically stable on presentation (systolic BP >90mmHg) but with evidence of right ventricular strain (elevated of troponin T due to myocardial injury, evidence of right heart strain on CTPA or ECHO)
- Low risk PE - the patient is haemodynamically stable with no signs of right ventricular strain. The majority of patients fall into this category. They may be suitable for outpatient ambulatory care within a robust clinical governance framework.
D.D of PE?
ØPneumonia ØCOPD ØCardiac failure Ø Pneumothorax Ø Myocardial infarction ØExacerbations of asthma
According to the Well’s score for PE, what score shows that PE may be likely or unlikely?
4 or more: PE likely
Less than 4: unlikely
What are the two things we would give a 3 on the PE wells score?
- Previous DVT
2. Diagnosis other than PE is less likely
When should we do the d dimer test in patients with suspected PE?
Only if their wells score is less than 4, since d dimer is a great negative predictor
First line imaging modality for PE?
CTPA
What is the alternative we use to the first line imaging investigation of PE and when is it contraindicated?
Ventilation/Perfusion lung scan (V/Q scan). Not appropriate if D-dimer negative and Wells score suggests PE unlikely. Must perform pregnancy test first in women of child-bearing age
Most common finding in an ECG of a PE patient?
Sinus tachycardia
Under what condition do we perform Duplex ultrasound for a PE patient
This test is useful to increase the likelihood of reaching a diagnosis in patients with probable PE (Wells’ score > 4 or have a positive D-dimer test) whose CTPA is negative.
In such patients, compression ultrasound may reduce the need for performing pulmonary angiography (which is very invasive however the most accurate tests)
Summarize the imaging modalities for PE in order of importance
- CTPA
- V/Q scan
- Duplex
- Echo (will relatively diagnose massive PE and right sided failure)
- Pulmonary angiography
- Chest x ray
Lab tests for PE?
ABG / D dimer / Troponin T (may be elevated)
Treatment of PE?
-Low risk PE – treatment same as for acute DVT. ( check the DVT lecture)
-Intermediate risk PE (sub-massive PE): Administer bolus dose of IV Unfractionated Heparin (80 Unit/kg), followed by daily s/c LMWH. Follow with warfarin as per acute DVT.
-Massive PE – thrombolysis is first line treatment.
Ø If cardiac arrest about to happen , may thrombolyse patient on clinical grounds alone (without imaging or lab tests).
Ø Follow thrombolytic therapy up with unfractionated heparin infusion and then warfarin.
(WARFARIN GIVEN EXACTLY AS DVT IN PROVOKED AND UNPROVOKED GROUPS)
What are the 3 palpable pulses of the lower limb?
femoral: located along the crease midway between the pubic bone and the anterior iliac crest. Use the tips of your 2nd, 3rd and 4th fingers.
posterior tibial: palpated halfway between the posterior border of the medial malleolus and the Achilles tendon.
dorsalis pedis: palpated lateral to the extensor hallucis longus tendon (between 1st and 2nd toe)
and sometimes the popliteal
What do we find in the lower extremities of someone with PAD?
Hair loss
Brittle nails
What do we do to a patient who got PE when anticoagulants are contraindicated?
inferior vena cava filter is inserted to prevent recurrent episodes of pulmonary embolism.
In addition to anticoagulant s, what should we give a patient with PE?
Morphine , oxygen , thrombolytics , anticoagulant , embolectomy.
Which vein takes the distribution of: medial aspect of the mid-thigh running down to the knee
Long saphenous vein
Define varicose veins
dilated , elongated tortuous veins
Treatment of varicose veins.?
Graded elastic stockings
Sclerotherapy
Endogenous laser
Symptoms of varicose veins
the most common being aching or heaviness, which typically increases throughout the day or with prolonged standing and is relieved by elevation or compression. ANA 7ASES B TO2L
- Other less common symptoms include ankle swelling and itching.
- REMEMBER-PATIENT WITH VARICOSE SHOULD BE EXAMINED WHILE STANDING
What does the location Of varicose veins tell us about the veins affected?
Medial thigh and calf varicosities suggest long saphenous incompetence
• Posterolateral calf varicosities are suggestive of short saphenous incompetence
• Whereas anterolateral thigh and calf varicosities may indicate isolated incompetence of the proximal anterolateral long saphenous tributary.
Manage,ent of venous ulcers?
Life style modification (movement to encourage venous return)
Leg elevation
Compression
Graduated class I or II elastic stockings
Varicose vein surgery
Does lymphedema cause pitting or non Pitt oedema?
NON PITTING
What conditions cause pitting or non pitting oedema?
Except lymphedema and myxedema, most other diseases cause pitting edema. Lymphedema is initially pitting
