Vascular System - Aortic Aneurysm and Dissection Flashcards
Aneurysm definition
A localised dilatation of an artery with at least a 50% increase in diameter compared to expected normal diameter
Features of true aneurysms
Involve all 3 layers of arterial wall
Fusiform or saccular in shape
Features of false aneurysms
Hole in arterial wall
Pulsatile haematoma contained by adventitia & surrounding tissues
Location of true aneurysms
Abdominal aorta and iliac Popliteal Femoral Thoracic aorta Thoracoabdominal aorta
Location of false aneurysms
Radial
Femoral
Anastomotic
Symptoms of aneurysms
Expansion thus compression/ eroding adjacent structures
Rupture
Distal embolism
Thrombosis
How can AAA cause death
Rupture (need out) or back pain by erosion of lumbar vertebrae but most are asymptomatic
Epidemiology of AAA
6,000 deaths per yr in UK
2% of death in men aged 65+ yrs
Risk factors of AAA
Male 65+ yrs Smoking HTN 1st degree relative with AAA (CTD) - rare cause of thoracic and abdominal aortic aneurysm
Px of AAA
Most are asymptomatic
Pain and/or tenderness
Px of AAA rupture
Abdominal pain radiating to back
Collapse
Pulsatile abdominal mass
Px of AAA embolisation
ALI (6 P’s)
Blue toe syndrome
Blue toe syndrome
Ischaemic toes with palpable foot pulses
Suggest micro-embolisation from atherosclerotic plaque or aneurysm
National AAA Screening Programme
Started in 2010
All men invited for screening US in 65th yr
Older men can self-refer
Risk of rupture of AAA
Normal aorta measure up to 2.5 cm in diameter
Risk of rupture of AAA increases w/ size
Size of 5.5 - 6cm has a risk of 5-15%
AAA and driving
Car drivers can continue if <6cm, must notify DVLA between 6-6.4cm and must stop when 6.5cm
Bus/lorry drivers must notify if <5.5cm and must stop if more
Mx of small AAA
Antiplatelet, statin, smoking cessation and treatment of HTN
Mx of small AAA - <3cm
No follow-up required if aged 65+
Mx of small AAA - 3-4.5cm
12 monthly surveillance US
Mx of small AAA - 4.5-5.5cm
3-6 monthly surveillance US
Mx of small AAA - >5.5 cm
Consider surgery
Indications of AAA surgery - Asymptomatic
Diameter > 5.5 cm
Increase in size > 1cm in a yr
Indications for AAA surgery - symptomatic
Rupture
Pain and/or tenderness (impending rupture)
Distal embolisation (ALI or blue toe syndrome)
Pre-operative assessment for aneurysm surgery
Bloods/ CXR/ ECG/ LFTs/ cardiopulmonary exercise test
Anaesthetic pre-assessment
Optimise cardiac, resp and renal functional
Ensure antiplatelet and statin
Consider age, frailty, co-mordities, pt wishes
Why should you ensure antiplatelet and statin before aneurysm surgery
Reduces risk of peri-operative MI
Open repair
Laparotamy incision in the midline from xiphisternum to pubic symphysis under GA
Aorta is identified in retroperitoneum
Heparin given as prophylaxis
Tubular graft is sewn to aorta inside sac
Complications of open repair
Death
Bleeding
Ischaemia - limb (ALI or trash foot) or colon (iscahemic colitis)
Cardiac, resp and renal failure
Wound infection, dehiscence and incisional hernia
Adhesive small bowel obstruction
Worst complications of open repair of aneurysms
Graft infection
Aorta-enteric fistula
Anatomical suitability for EVAR - aneurysm
Diameter < 30mm
Length >15 mm
Shape - cylindrical not canal
Angulation
Anatomical suitability for EVAR - iliac access and fixation
Patency
Diameter
Length
Tortuosity
Complications of EVAR
Death Contrast and radiation toxicity Wound haemotoma, serum, infection Damage to access vessels Lifelong surveillance required
What are re-interventions of EVARs usually due to
Slipping Kinking Thrombosis Endoleak Rupture
Endoleaks
Blood flowing out of the stent graft but inside the aneurysm sac
Can be low pressure or high pressure
May spontaneously seal with time
What can endoleaks cause
Expansion
Rupture
Type 1 endoleaks
Caused by poor seal between graft and aneurysm neck or iliacs Uncommon High pressure V concerning High risk of rupture
Type 2 endoleak
Caused by back bleeding lumbar arteries or IMA Common Usually low pressure Only concerning if sac is expanding Low risk of rupture
Mortality of open repair vs EVAR
Higher vs lower
Hosp stay in open repair vs EVAR
Longer in HDU bed vs shorter in ward bed
Late mortality of open repair vs EVAR
Lower vs higher
Who is open repair ideal for
Younger, more fit pts
What is EVAR better for
Older, less fit pts
Ruptured AAA - surgical emergency
Clinical dx
Emergency surgery
Try assess co-morbidities, pt and family wishes
Take bloods for FBC, U&E, glucose, clotting and crossmatch
Fluid resus to maintain BP
Invoke massive transfusion protocol
Clinical dx of rAAA
Age > 50yrs
Abdominal/back pain
Shock
What can popliteal aneurysm cause
Can cause a/c or c/c limb ischaemia by thrombosis or distal embolisation or DVT by compression of popliteal vein
Epidemiology of PAA
Commonest true peripheral aneurysm
50% bilateral
40% also have AAA
Indication for popliteal aneurysm surgery - asymptomatic
Diameter > 2-3cm
Significant lining thrombus
Indications for surgery - symptomatic PAA
Thrombosis (causing ALI)
Distal embolisation (causing c/c limb ischaemia or blue toe syndrome)
DVT (from compression of popliteal veins)
Typical popliteal artery bypass graft
Saphenous vein graft connecting superficial femoral artery and below-knee popliteal artery
Example of exclusion bypass
Endovascular treatment of PAA
Stent grafting
Thrombolysis
Stent grafting for PAA
Less morbidity and mortality
Inferior latency due to kinking and thrombosis
Thrombolysis for PAA
May clear run-off vessels in thrombosed popliteal aneurysm to allow bypass or stunting
How can other types of aneurysms cause death
Juxta-renal, suprarenal, thoraco-abdominal and thoracic aneurysms can cause death by rupture
What must be preserved during aneurysm repair
Blood supply
What are false radial or femoral aneurysm usually caused by
Iatrogenic arterial puncture
Treatment of false radial or femoral aneurysm
Spontaneous thrombosis
US guided compression
Thrombin injection
Surgery
Classification of aortic dissection
Type A
Type B
Type A aortic dissection
Start proximal to the left subclavian artery and involve the ascending aorta
Type B aortic dissection
Start distal to the left subclavian artery and involve the descending aorta
Epidemiology of aortic dissection
3-4 people per 100,000/yr in UK
M 3x more than F
Peak ages 50-65 yrs
Risk factors for aortic dissection
HTN Atherosclerosis Aortic aneurysm Bicuspid aortic valve Coarctation of aorta Fhx CTD Pregnancy Cocaine use High-intensity weightlifting
Px of aortic dissection
Tearing chest pain radiating to back Collapse Pulse deficits Radio-radial or radio-femoral delay Difference in BP between arms > 20 mmHG New aortic regurgitation murmur Neurological signs of strokes or paraplegia
Ix of aortic dissection
CXR
ECG
CT/ CTAngio
ABG
CXR for aortic dissection
Widened mediastinum
Pleural effusion/ haemothorax
ECG for aortic dissection
Ischaemic changes of coronary arteries malperfused
CT angiogram for aortic dissection
Intimal flap
True and false lumen
Branch vessel perfusion
Complications of aortic dissection
Malperfusion
Rupture
Aneurysmal dilatation
Complications of aortic dissection - malperfusion
Coronary --> MI Carotid --> stroke Spinal --> paraplegia Renal --> renal failure Mesenteric --> a/c mesenteric ischaemia Limb --> ALI
Mx of Type A aortic dissection
Open surgery to replace ascending aorta +/- arch +/- aortic valve
May require re-implantation of coronary arteries or great vessels
Mx of Type B aortic dissection - uncomplicated
Analgesia - morphine
Strict control of BP with IV labetalol (systolic 100 -120)
Surveillance
Mx of Type B aortic dissection - complicated
TEVAR to cover entry tear and promote thrombosis of false lumen
Symptoms of complicated Type B aortic dissection
Ongoing pain Uncontrolled BP Malperfusion Aneurysmal dilatation Rupture
Impact on family in chronic illness in childhood
Changes in roles, role expectations, responsibilities and patterns of interactions
Loss of ‘perfect’ child
Increased practical & emotional stress, depression
Strain on parental rships
Why is coping important
Severe illness and the many challenges associated with it can be viewed as stressors
Place demands on pt, requiring adaptation
Adaption achieved via physiological, behavioural, cognitive, emotional response
How can coping strategies be classified
In terms of function served, methods/ modes, type of action
Most common coping classification distinguishes
Emotion-focused coping
Problem-focused coping
Emotion-focused coping
Aimed at modifying response by regulating the emotional distress caused by the stressor or potential stressor
Problem-focused coping
These strategies attempt to alleviate or eliminate stressful situations through trying to take control i.e. doing something constructive about -ve events
Spp coping strategies - problem focused
Problem solving Support seeking Escape avoidance Distraction Cognitive restructuring
Spp coping strategies - emotional focused
Rumination Helplessness Social withdrawing Emotional regulation Info seeking Negotiation Opposition Delegation
When should problem-focused coping strategies be used
In controllable situations
When should emotion focused coping strategies be used
When there is no/little control
Coping in the a/c phase vs c/c phase
Emotion-focused coping in a/c and problem-focused in c/c is best
Influences on coping
Illness related factors
Background/ personal factors
Physical/ environmental factors
Illness related factors influencing coping
Level of threat to life/ functioning
Obviousness
Treatment regimens
Side effects
Background/ personal factors influencing coping
Personality Socio-demographic Timing in life Knowledge Beliefs Motivation Education
Phsyical/ environmental factors influencing coping
Hosp/ home environment Social support Finance Resources availability Educational opportunities
What factors can facilitate coping and adjustment in c/c childhood illness
A flexible, cohesive and supportive family with open and clear communication
Parental coping style is adaptive
General support system
Pre-illness personality and functioning of the child
Understanding of disease
The clinicians role in coping
Identify challenges
Steer emotion or problem-focused coping in +ve direction
misconception
Introduce pts to ideas of coping
Ensure pts equipped to adopt necessary coping
Assess and enhance social support
Branches of the arch of aorta
From L - R
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
What does the brachiocephalic trunk give rise to
Right subclavian artery
Right common carotid artery
Posterior intercostal arteries
Branches of descending thoracic aorta found at each vertebral level
What do the posterior intercostal arteries anstamose with
Anterior intercostal arteries
What are the anterior intercostal arteries a branch of
Internal thoracic artery
Where do the internal thoracic arteries lie
Parasternally
Venous drainage of the thoracic cavity
Azygous venous system
Azygous vein
Found on the right
Drains into superior vena cava
Where is the hemiazygous vein found
On the left, where intercostal veins drain into
What does the hemiazygous vein drain into
Main azygous vein
Thyro-cervical trunk as branch of subclavian artery
Thyro-cervical artery –> supra scapular artery –> circumflex scapular arteries
Where does the internal thoracic artery branch from
Subclavian artery
Where does the abdominal aorta pass through the diaphragm
T12
Unapired arteries of abdominal aorta
Coeliac axis
Superior mesenteric artery
Inferior mesenteric artery
Paired arteries of abdominal aorta
Inferior phrenic arteries
Middle suprarenal arteries
Renal arteries
Gonadal arteries
What level does the inferior phrenic arteries leave at
T12
What level does the coeliac axis/ trunk leave at
T12
What does the coeliac axis supply blood to
The foregut - stomach, first 2 parts of duodenum, liver, spleen and pancreas
Which level does the middle suprarenal arteries leave at
L1
What do the middle suprarenal arteries supply blood to
Suprarenal gland
What level does the superior mesenteric artery leave at
L1
What does the superior mesenteric artery supply blood to
Midgut
What does the midgut consist of
3rd and 4th part of duodenum Rest of small intestine (jejunum and illeum) Caecum Ascending colon 2/3rds of transverse colon
What levels do the renal arteries leave at
Between L1/2
What level do the renal arteries leave at
L2
What level does the inferior mesenteric artery leave at
L3
What does the inferior mesenteric artery supply blood to
Last third of transverse colon
Descending colon
Rectum
Where does the abdominal aorta bifurcate
L4 - umbilicus
What is the inferior vena cava formed by
The union of common iliac veins at L5
Where are parietal vessels found
Coming off at each vertebral level
All paired
What do the parietal vessels supply
Body wall
Diaphragm
Where are the lumbar arteries found
Leaving each vertebral level from L1 - L4
What do paired visceral arteries supply
Bilateral organs
Why does venous drainage from the abdomen have to pass through the liver
Venous blood holds all the digestion products
What does the hepatic vein drain into
Inferior vena cava
What is the portal vein formed from
Splenic vein
Superior mesenteric vein
Inferior mesenteric vein
What do the vertebral arteries join together to form
Basilar artery
What is the basilar artery a branch of
Subclavian artery
What do the basilar arteries give rise to
Pontine arteries
Posterior cerebral artery –> posterior communicating artery
Where does the left common carotid bifurcate at
L4
Into internal carotid artery and external carotid artery
Branches of internal carotid artery
Middle cerebral artery
Opthalmic artery
Anterior cerebral artery –> anterior communicating artery
Branches of external carotid artery
Facial artery
Maxillary artery
Occipital artery
Superficial temporal artery
Venous drainage of head and neck
No veins, instead there are sinuses
Sinuses
Venous channels running in between meningeal layers
What does confluence of sinuses in the head form
Internal jugular vein
What is the axillary artery a part of
Brachial plexus
Where does the axillary artery start at
Lateral border of 1st rib
Origin of axillary artery
Subclavian
Where does the brachial artery start
Inferior border of teres major
What does the brachial artery pass under
Bicipital aponeurosis
What does the bicipital aponeurosis do
Anchors biceps brachii to medial side
Separates arterial and venous vessels
Which arteries start at the antecubital fossa
Radial artery
Ulnar artery
Which is artery is deeper - radial or ulnar
Ulnar is deeper
Radial is more superficial
What does the radial artery pass through
Anatomical snuffbox
1st webspace
Deep palmar arch
Comes from radial artery
What does the deep palmar arch anastomose with
Superficial palmar arch
Testing the anastomosis between the palmar arches
Allen’s test
Which artery supplies the scaphoid
Radial
Path of ulnar artery
Passes under pronator teres and rests under flexor carpi ulnaris
Runs alongside ulnar nerve
What does the ulnar artery run in
Guyon’s canal
What does the ulnar artery pass over
Flexor retinaculum (no risk of compression)
What does the ulnar nerve create
Superficial palmar arch - metacarpal branches, digital branches
Arterial supply of upper limb
Subclavian –> axillary –> brachial
- -> radial –> deep palmar arch
- -> ulnar –> superficial palmar arch
Superficial veins of arms
Dorsal venous arch - cephalic, basilic, median cubital vein
Where is the cephalic vein found
Radial side of arm
Where is the basilic vein
Ulnar side of arm
Where is the median cubital vein found
In between cephalic vein and basilic vein
Where do the veins in the dorsal venous arch drain into
Brachial vein as well as radial and ulnar vein
At same landmarks turn into axillary vein then subclavian
Which veins in the arms also drain into subclavian vein
Cephalic
Basilic
Deep veins in arms
Radial Ulnar Brachial Axillary Subclavian
What supplies blood to the pelvis
Primarily internal iliac artery
What do the common iliac arteries divide into
External iliac artery
Internal iliac artery
Branches of internal iliac artery
Umbilicus artery
Obturator artery
Superior and inferior gluteal arteries
Venous drainage of pelvis
Matches arteries
Start of femoral artery
Inguinal ligament
Division of femoral artery
Profunda femoris
Superficial femoral artery
What does profunda femoris supply
Anterior and posterior aspects of thigh
2 circumflex femoral arteries from perforating arteries join with cruciate anastomosis around hip joint - creates retinacular vessels
What is the femoral triangle bound by laterally
Sartorius
What is the femoral triangle bound by medially
Adductor longus
What is the femoral triangle bound by superiorly
Inguinal ligament
What is the floor of the femoral triangle
Pectinueus and Iliopsoas
Roof of the femoral triangle
Skin
Where does the femoral artery sit at
Mid-inguinal point
Mid-inguinal point
Found between pubic symphysis and ASIS
Midpoint of inguinal ligament
Between pubic tubercle and ASIS
What is the popliteal fossa found by superiorly
Hamstring muscles
What is the popliteal fossa bound by laterally
Rectus femoris
What is the popliteal fossa bound by medially
Semimembranosus
Semitendinosus
What is the popliteal fossa bound by inferiorly
Gastrocnemius
Where does the popliteal artery start
Adductor hiatus
What do the popliteal arteries give rise to
Genicular arteries
How many genicular arteries do we have in each leg
4
Superior and inferior, both lateral and medially
These form an anastomosis around knee joint
What do popliteal arteries divide into
Posterior and anterior tibial arteries at the inferior border of popliteus
Terminal branch of anterior tibial artery
Dorsalis pedis at ankle joint
Branch of posterior tibial artery
Lateral - peroneal artery
Terminal branch of posterior tibial artery
Medial and lateral plantar arteries
Deep venous drainage of legs
Anterior tibial vein Posterior tibial vein Popliteal vein Femoral vein External iliac vein
Superficial drainage of legs
Dorsal venous arch - short and long/great saphenous veins
Where does the long saphenous vein run from
Runs from medial aspect of dorsal venous arch and drains into femoral vein
Short saphenous vein
Runs posteriorly and laterally to drain into popliteal vein
What is venous blood pushed around by
Arterial pressure
Features helping venous drainage in legs
Soleal pump o pushes on veins and causes blood to travel up
Deep fascia compartmentalising muscles - when muscles contracts, pushes on veins
Venae commintantes
Veins running alongside arteries
Structures at particular risk of supracondylar humeral fracture
Brachial artery
Median nerve
Arterial supply to the lower limb
External iliac –> femoral –> popliteal
- -> anterior tibial –> dorsalis pedis
- -> posterior tibial –> peroneal
Where are aortic aneurysms usually located
Abdomen - infrarenal to bifurcation
What does lifelong surveillance of EVAR entail
Yearly CT and/ or US
Monitoring position of stent grafts, size of aneurysm sac and any endoleaks
Symptoms of ruptured aneurysm - haemorrhage
Hypotension
Pale, clammy
High HR
Investigation for ruptured aneurysm
ECG
Amylase
CT
