Aneurysms Flashcards
Definition of an aneurysm
Dilatation of all layers of the aorta leading to an increase in diameter of over 50% (in AA the diameter will be >3.5cm)
Causes of aneurysm
Degenerative disease
Connective tissue disease eg Marfan’s
Infection (mycotic aneurysm)
Risk factors
Male Age Smoking Hypertension Family history (30% in 1st degree male relatives)
Prevalence of 3% in the uk
Presentation of AAA
Asymptomatic, screening is used
Criteria for a screening test
Definable Prevalence Severity Natural history Reliable detection Early detection confers advantage Treatment available Cost Feasibility Acceptability
4 outcomes of AAA screening
Normal Small AAA (3-4.4cm) annual scans Medium AAA (4.5-5.5cm) 3 monthly scans Large AAA (over 5.5cm)
Impending rupture of AAA symptoms
Increasing back pain and is tender
Symptoms of AAA rupture
Abdo/back/flank pain
Painful pulsatile mass
Haemodynamic instability
Hypoperfusion
Unusual presentation of ruptured AAA
Distal embolism Aorticaval fissure Aortoenteric fistula Ureteric occlusion Duodenal obstruction
UK small aneurysm trial Lancet
Surgical repair of 4-5.5cm aneurysms doesn’t confer any benefit
With surgery 30day mortality is 5.8%
Risk of rupture is 1% per year
Patient fitness for surgery criteria
Full history and examination Bloods ECG ECGI PFTs MPS CPEX End of bed test Patient preference
Different advantages of USS Vs CTA/MRA
USS- no radiation or contrast and is cheap but operator dependant and can’t plan surgery
CTA/MRA- quick, not operator dependant, needed for surgery planning (detail) but uses contrast and radiation
Treatment
Conservative (not fit) and consider event of rupture
Endovascular repair
Open repair
Complications of open repair
There are many
Eg wound infect etc
Damage to bowels and ureters veins and nerves hernias embolus
DVT/PE
MI
Stroke
Death
Complications of endovascular repair
Same as open but endoleak, femoral dissection, ischaemia etc
Types of endoleak
type I: leak at graft ends (inadequate seal) - most common after repair of thoracic aortic aneurysms 4
type II: sac filling via branch vessel (e.g. lumbar or inferior mesenteric artery)
most common after repair of abdominal aortic aneurysms 4 (80%)
sometimes referred to as a “retroleak”
most spontaneously resolve and require no treatment
type III: leak through a defect in graft fabric (mechanical failure of graft)
type IV: a generally porous graft (intentional design of graft)
type V: endotension
EVAR study 1 and 2
1 sees 3fold reduction in operative mortality for EVAR and improved qol but no difference in overall mortality for open surgery
2 was against no intervention if unfit for open surgery
No difference in mortality, 9% opmort and 9% rupture rate per year
Emergency open repair
Straight to theatre Massive transfusion protocol Rapid anaesthetic Laparotomy xiphisternum to public symphysis Occlude aorta proximally 30-50% mortality
Emergency EVAR
Only if anatomical suitability
Local anaesthetic
For rupture no difference in mortality from open surgery
Carotid disease
Atherosclerosis is associated with ischaemic stroke and Tia
Vascular surgeons involved to manage for prevention
Virchow’s triad
Flow
Vessel wall
Coaguability
Diagnosis of carotid artery atherosclerosis stroke or tia
Normal stroke exam
Plus auscultation and USS of carotids
Poiseuilles law
As radius of a vessel decreases, velocity increases
<125cm/s <50% stenosis
>125 50-69% stenosis
>270 70-79% stenosis
End diastolic velocity >140 80-99% stenosis
Management of carotid Artery disease
Smoking cessation Control of hypertension Antiplatelets Statins diabetic control
Carotid endarterectomy
Incision
plaque removed
Artery closed
May prevent stroke
Complications of carotid endarterectomy
Wound infection, scar etc
Nerve damage (vagus and hypoglossal)
Perioperative stroke from plaque rupture, hypoperfusion
When is stenting or endarterectomy used instead of best medical treatment
Over 50-70% (nascet-ECST) stenosis
Management of asymptomatic patients
CEA more benefits in males or bilateral disease
Asymptomatic should only be operated on by operators with good risks and for stenosis of 60-89% in under 75s
