Vascular Flashcards
What is Paget-Schroetter Syndrome?
A type of thoracic outlet syndrome caused by venous compression between first rib, clavicle and medial border of anterior scalene muscle resulting in upper limb DVTs.
Can be associated with body building (subclavius hypertrophy, axillary vein microtrauma)
What are the symptoms of thoracic outlet syndrome most commonly due to?
Neurogenic - 80-90% of cases with ulnar nerve root distribution symptoms. There is often no anatomical abnormality identified
What is Adson’s sign?
Loss of radial pulse in abducted arm by rotating head to ipsilateral side with extended neck after deep inspiration - a sign of TOS, although not specific
What are the borders and contents of the thoracic outlet?
Borders
1. Superior - Clavicle
2. Inferior - 1st rib
3. Lateral - middle scalene/cervical rib (if present)
Contents
1. Subclavian vein (medial)
2. Anterior scalene
3. Subclavian artery + brachial plexus (lateral)
What is Charcot’s Foot?
Neuropathic arthropathy with degeneration of weight bearing joint (often tarsometatarsal or metatarsophalangeal joints).
Presents as a hot swollen foot (joint) with palpable pulses in patient with peripheral neuropathy
Which 5 nerves can be injured during carotid endarterectomy, and how do these manifest?
- VII (Facial), marginal mandibular branch - ipsilateral drooping
- IX (glossopharyngeal) difficulty swallowing
- XII (hypoglossal) ispilateral tongue deviation (taste normal)
- Superior laryngeal - voice quality and high pitch phonation
- X (Vagus) - hoarseness or impaired cough
What are the characteristic arterial findings in Buerger’s disease?
Corkscrew arteries in both involved and unaffected limbs
Occurs in mostly Men between 20-40, smokers and usually distal extremities. Needs exclusion of proximal embolic and hypercoagulable states for diagnosis
What is the most common cause of prosthetic graft infection?
Staphylococcus species - (epidermidis or MRSA) - about 50%
Remainder pseudomonas, proteus, e.coli.
MRSA has a poor prognosis
What is the Samson classification of Prosthetic Graft infection (1-5)
- Confined to Dermis
- Involves SC tissue not contacting graft
- Involves body of graft but not anastomosis
- Involves exposed anastomosis without bacteraemia/haemorrhage
- Involves exposed anastomosis with bacteraemia/haemorrhage
What classification system can be used to grade arterial ischaemia?
Rutherfords
From which cells do Carotid body tumours arise?
Paraganglion cells.
Carotid body tumours arise at bifurcation splaying internal/external carotid arteries. They are more common in women and diagnosed in 40-50%
10% familial. Usually benign and mobile side-side
What is the inheritance of carotid body tumours?
Usually autosomal dominant.
May be associated with MENIIa or IIb or Von Hippel-Lindau syndrome
What is the genetic abnormality in Von Hippel Lindau syndrome?
Mutation of VHL tumour suppressor on Chromosome 3 (3p25-26)
What tumours are seen in Von Hippel Lindau syndrome?
Haemangioblastomas (cerebral in 60-80%, most common presentation), Phaeochromocytomas, RCC, Pancreatic serous cystadenoma
Retinal angiomatosis –> visual loss
How do Carotid body tumours present?
Slow growing spherical neck mass which may cause cranial nerve palsies (IX, X, XII).
Fixed in carotid sheath so can go side to side but not up and down
Endoscopic Thoracoscopic sympathectomy targets which nerve ganglions?
T2,T3 +/- T4 of paraspinal sympathetic chain
Hyperhidrosis when refractory to medical management with antiperspirants, anticholinergics and botox
80% satisfaction rates, 85-95% symptom improvement.
86% compensatory sweating (contralateral side)
<25% gustatory sweating
<5% cardiac sympathetic denervation
1-2% Horner’s Syndrome
Describe the 5 types of endoleak
In patients with an AAA, how many will also have popliteal aneurysms?
2-10%
Popliteal aneurysms are bilateral in 50% of cases
In patients with a popliteal aneurysm, how many will have a coexisting AAA?
40%
When should popliteal aneurysms be repaired?
In general if they are symptomatic (although they most often present with occlusion/embolisation i.e. acutely, rather than with claudication), or over 2cm. Definitely over 3cm
Usually bypass and exclude
When should carotid endarterectomy be performed?
70-99% symptomatic stenosis of ipsilateral carotid
Small benefit for 50-69% stenosis (NASCET)
What is Subclavian steal syndrome?
Retrograde flow of blood down vertebral artery to distal subclavian artery if proximal subclavian is stenosed/occluded.
Blood flows through common carotid to circle of Willis and back to vertebral
Most patients are asymptomatic, and can be treated with secondary prevention techniques.
Angioplasty is usually first line interventional, but can do transposition or bypass. Endarterectomy is not performed
Which coagulation factors are degraded by Protein C and Protein S
Factor V
Why does Factor V Leiden cause hypercoagulability
The mutated Factor V is not inactivated by protein C
How does Antiphospholipid syndrome cause hyper coagulability?
APL inhibits protein C which normally degrades factor V
Absolute contraindications to thrombolysis (6)
- Active bleeding (not menorrhagia)
- Aortic Dissection
- Cerebral aneurysm or AVM
- Intracranial neoplasia
- Previous cerebral/intracranial haemorrhage (ever)
- Recent thromboembolic stroke
Relative contraindications to thrombolysis (7)
- Active PUD
- Bleeding diathesis (tendancy to bleed) or anti coagulated
- Pregnancy
- Recent head trauma (2-4 weeks)
- Recent GI Bleeding (within 6 months)
- Recent major surgery (2-3 weeks)
- Severe hypertension (>180/110)
What is the most common type of visceral artery aneurysm?
Splenic 60-80%
Hepatic 20%
SMA, GDA, pancreatic 6%
IMA <1%
What is the most common site of compartment syndrome in the leg?
Anterior compartment of both upper and lower legs
What are the compartments of the the thigh?
Anterior, posterior and medial
What are the compartments of the lower leg?
Anterior, lateral, superficial posterior and deep posterior
Describe the Crawford system for Aortic Aneurysms
For thoracoabdominal aneurysms.
1 - L SCA to suprarenal aorta
2 - L SCA to aortic bifurcation
3 - 6th rib/IC space to aortic bifurcation
4 - Diaphragm to aortic bifurcation
5 - 6th rib/IC space to suprarenal aorta
Describe the De-bakey and Stanford classifications
Stanford A/Debakey I-II originate in ascending aorta proximal to left subclavian
Debakey I is ascending/descending (60%)
Debakey II ascending only (10%)
Debakey III descending only (30%)
What is the most common type of aortic dissection
Ascending and descending (60%)
10% confined to ascending
30% descending only
Which of the following is protective against vascular restenosis?
von Willebrand Factor
Vascular endothelial growth factor
Platelet derived growth factor
ICAM-1
E-selectin
VEGF - angiogenic factor, creates new blood vessels, promotes endothelial recovery.
vWF = platelet adhesion
ICAM1 = adhesion migration of leucocytes
E-selectin - endothelial dysfunction, lymphocyte migration
PDGF - smooth muscle migration and intimal thickening
What is Nutcracker syndrome?
Compression of left renal vein between aorta and SMA
Amputations
1. Symes
2. Lisfranc
3. Burgess
4. Chopart
5. Ray
6. Gritti-Stokes
- Ankle amputation, provides durable end and reliant on good PTa
- Through tarsometatarsal joint
- Proximal tibial/fibular amputation with long posterior flap
- Disarticulation at midtarsal joint
- Through distal metatarsal head
- Below knee resection of supracondylar femur and stick patella onto end
What classification system is used for venous incompetence
The CEAP classification.
Main distinction is primary (Ep) or secondary (Es) or congenital (Ec)
With increasing severity going C1 (superficial) to C6 (active ulcer)
What is the most common side effect of statins?
Myopathy (1.5-3%)
What is the most problematic side effect of Gadolinium?
Nephrogenic systemic fibrosis - contraindicated where eGFR <60
Which syndrome is associated with congenital lymphedema?
Milroy’s disease
Also pitting, skin changes
Autosomal dominant
What is the difference between Parkes-Weber and Klippel Trenaunay syndrome?
In KTS there are capillary venous and lymphatic malformations associated with limb overgrowth
In PWS there is the same along with AVFs.
Where should AV fistulae be sited?
In the non-dominant arm and as distal as possible apparently
1) Snuffbox
2)Radiocephalic (Brescia-Cimino) fistula
3) Braciochephalic
4) transposed brachiobasilic (needs transposition)
Which arteries cause Type 2 Endoleaks?
Usually IMA or lumbar or median sacral arteries
What is May-Thurner syndrome?
Compression of LCIV by RCIA
Leads to DVT - consider where no provoking factors, more common in women
What is popliteal entrapment syndrome?
Compression of popliteal artery due to anatomical variant at knee - with abnormal attachment of gastrocnemius lateral medial to popliteal artery
What are important trials in AAA?
UK SAT Chichester/MASS trials and US Veterans studies.
Caucasian smokers 50-79 had higher prevalence - 4.9% of people
MASS trial defined aneurysmal as >3cm
What is the UK screening program for AAA?
Single USS of males at 65.
If <3cm - discharge
3-4.4cm - annual USS
4.5-5.4cm - 3/12 USS
5.5 or greater –> urgent referral for CTA
What is the aneurysm rupture risk at 1 year for:
1) 3-3.9cm
2) 4-4.9cm
3) 5-5.9cm
4) 6-6.9cm
5)>7cm
1) 0%
2) 1%
3) 11%
4) 11-22%
5) 33%
How can you classify types of vasculitis?
1) Aortic - Takayasu’s, Bergers, Giant cell arteritis
2) Large and medium - Buerger’s, Giant cell arteritis, Polyarteritis
3) Medium muscular - Polyarteritis, Wegener’s granulomatosis
4) Small muscular - Wegener’s, Rheumatoid vasculitis
What is Takayasu’s arteritis?
• Inflammatory, obliterative arteritis affecting aorta and branches
• Females> Males
• Symptoms may include upper limb claudication
• Clinical findings include diminished or absent pulses
• ESR often affected during the acute phase
What is Buergers Disease?
• Segmental thrombotic occlusions of the small and medium sized lower limb vessels
• Commonest in young male smokers
• Proximal pulses usually present, but pedal pulses are lost
• An acuter hypercellular occlusive thrombus is often present
• Tortuous corkscrew shaped collateral vessels may be seen on angiography
What is giant cell arteritis?
• Systemic granulomatous arteritis that usually affects large and medium sized vessels
• Females > Males
• Temporal arteritis is commonest type
• Granulomatous lesions may be seen on biopsy (although up to 50% are normal)
What is polyarteritis nodosa
• Systemic necrotising vasculitis affecting small and medium sized muscular arteries
• Most common in populations with high prevalence of hepatitis B
• Renal disease is seen in 70% cases
• Angiography may show saccular or fusiform aneurysms and arterial stenoses
What is Wegener’s granulomatosis?
• Predominantly affects small and medium sized arteries
• Systemic necrotising granulomatous vasculitis
• Cutaneous vascular lesions may be seen (ulceration, nodules and purpura)
• Sinus imaging may show mucosal thickening and air fluid levels
What is the commonest cause of acute mesenteric ischaemia?
Embolic (50%) - 50% survival, 30% if delayed
Thrombotic - usually prodromal, asymptomatic until >80% stenosis
Mesenteric vein thrombosis - 60% thrombophilia
What is the cause of a cervical rib?
Elongation of transverse process of 7th cervical vertebra - usually a fibrous band attaching to mid 1st rib
0.2-0.4% incidence
70% bilateral
Treat trans axillary approach
How can you grade femoropopliteal stenosis/occlusion
TransAtlantic Inter-Society Consensus (TASC)
A - single stenosis <5cm
B - Multiple stenosis <5cm, total <10cm, occlusion <3cm
C - multiple stenosis/occlusion >10cm
D - multiple occlusions >10cm
Key is that C or D lesions should be stented if plastid
When should fasciotomies be performed
Consider if >6hr since symptom onset
What is dysphagia lusoria?
Dysphagia due to aberrant right subclavian
What is superior mesenteric artery syndrome?
Angle between SMA and Aorta is 6-25deg (as opposed to 38-56)
3rd part of duodenum is constricted
4th part of duodenum may be high inserted.
What is Homan’s procedure
Indications for surgery
Marked disability or deformity from limb swelling
Lymphoedema caused by proximal lymphatic obstruction with patent distal lymphatics suitable for a lymphatic drainage procedure
Lymphocutaneous fistulae and megalymphatics
Procedures
Homans operation: Reduction procedure with preservation of overlying skin (which must be in good condition). Skin flaps are raised and the underlying tissue excised. Limb circumference typically reduced by a third.
Charles operation: All skin an subcutaneous tissue around the calf is excised down to the deep fascia. Split skin grafts are placed over the site. May be performed if overlying skin is not in good condition. Larger reduction in size than with Homans procedure.
Lymphovenous anastamosis: Identifiable lymphatics are anastomosed to sub dermal venules. Usually indicated in 2% of patients with proximal lymphatic obstruction and normal distal lymphatics.
What are the grades of compression stockings?
1) 14-17
2) 18-24
3) 25-35
Usually use Class 2 for venous ulcers
What is the 5 year patency rate of a PTFE above knee bypass?
47% (66% vein)
What is a potential reason for failure of thorascopic sympathectomy?
Failure to divide nerve of Kuntz between T1 and T2 (connection from 2nd IC nerve to first IC ventral rams)
How is LMWH derived?
Derived from UFH by depolymerisation to yield fragments about 1/3 the size of UFH.
How does LMWH differ from UFH? (4)
1) Reduced ability to catalyse inactivation of thrombin because the reduced size fragments cannot bind thrombin, but can still inactivate Xa
2)reduced non specific binding of plasma proteins, which results in increased predictability of dose-response relationship
3) reduced binding of endothelial cells and macrophages –> increased half life
4) reduced platelet binding (?reduced rate of HIT)
Why is Warfarin prothrombotic when started?
It inhibits Protein C > Protein S in addition to II, VII, IX and X, which take effect later
What is the evidence for the use of NOACs?
Einstein PE
Einstein DVT
both rivaroxaban - non-inferior to warfarin/enoxaparin
What is the evidence for thrombolysis in DVT?
CAVENT Study (2012) - reduced incidence of PTS for iliofemoral DVT
ATTRACT (2018) no overall advantage, subgroup of iliofemoral DVT shows reduced PTS
Within 14 days. Consider temporary filter (remove <6 weeks)
Describe the arterial anatomy of the leg
1) Femoral artery arises from external iliac beneath inguinal ligament
2) Divides into SFA (medially) and Profunda (thigh)
3) SFA enters posterior compartment of thigh through Hunters canal (sub sartorial canal) through opening in Adductor Magnus
4) The popliteal artery passes behind the knee, medial to the vein and tibial nerve and trifurcates at the lower border of popliteus
5) Anterior Tibial and tibioperoneal trunk (divides into posterior tibial and peroneal artery)
What is the appropriate technique for arteriotomy?
Usually should be transverse - will need patch closure if longitudinal
Close interrupted double ended prolene from inside to out
What size of Fogarty Catheter is used for embolectomy?
4/5 Proximal and 3/4Fr distal (3 times each way)
Where are Fasciotomy incisions made?
Full length skin incisions
1) Anterior - two fingers lateral to anterior border of tibia (beware common fibular nerve) –> anterior and lateral compartments
2) Posterior - two fingers posterior to the medial malleolus (superficial and deep posterior)
When would you consider thrombolysis for an acutely ischaemic limb?
Mostly where the limb is not immediately threatened and no contraindications. May be of particular use for thrombosed grafts
What is the stroke/TIA risk with a 75-99% Carotid stenosis at 1 year
19.5%
30-74% = 5.7
0-29% = 2.1