Aneurysm

Question 1

what is ananeurysm?

Answer 1

focal dilation of an artery >50% of the normal diameter of the vessel

Question 2

what size confirms an aneurysm in aorta, common iliac and popliteal?

Answer 2

aorta = >3cm
common iliac = >2.5cm
popliteal = >1cm

Question 3

what is a true vs false aneurysm?

Answer 3

true = involves all 3 layers of the arterial wall, blood contained within all 3 layers
false/pseudoaneurysm = vessel wall is damaged so blood leaks out and is contained within surrounding tissues

Question 4

how can aneurysms be classified by morphology?

Answer 4

fusiform (vessel is symmetrically swollen)

saccular/berry (swells out the way)

Question 5

what should you look for in a popliteal aneurysm?

Answer 5

other aneurysms

commonly have one in other politeal and an AAA

Question 6

most AAA are what shape?

Answer 6

fusiform

Question 7

congenital causes of aneurysm?

Answer 7

connective tissue disorder (marfans, ehlers danlos etc)

PKD associated with cerebral aneurysms

Question 8

acquired causes of aneurysm?

Answer 8

vasculitis
infectious (syphilis, TB etc)
most are idiopathic (possibly due o to collagenase imbalance)
trauma

Question 9

modifiable risk factors?

Answer 9

smoking
hypertensino
high cholesterol
obesity

Question 10

non-modifiable risk factors?

Answer 10

male gender
age
family history
ethnicity 
known coronary artery/peripheral vascular/carotid/cerebrovascular disease)

Question 11

which aneurysms are most likely to rupture?

Answer 11

risk increases with size

Question 12

mortality of AAA rupture?

Answer 12

75% wont make it to hospital

25% of those who make it to hospital wont make it

Question 13

what can give better chance of making it to hospital in AAA?

Answer 13

if it ruptures into retroperitoneal space meaning its contained
(rapidly fatal if it ruptures into the intra-peritoneal space as it can just keep bleeding)

Question 14

what other problems can an aneurysm cause?

Answer 14

thromboembolic events

local pressure effects (mainly in politeal)

Question 15

why does risk of rupture increase with size?

Answer 15

law of la place
larger vessel radius = more tension required to withstand internal fluid pressure, so when artery wall expands, the wall gets thinner but the tension on the wall increases, increased tension leads to more expansion and greater risk of rupture

Question 16

how is AAA diagnosed?

Answer 16

men >65 are screened via abdominal USS
do USS if suspicious of asymptomatic USS
do CT angiogram if symptomatic or suspected rupture
most are found incidentally however

Question 17

where do you examine for an AAA?

Answer 17

palpate for expansile mass above the umbilicus (AA bifurcates at umbilicus level)

Question 18

what symptoms might you get from AAA?

Answer 18

usually pain or pulsatile feeling but usually asymptomatic

Question 19

how is asymptomatic AAA managed?

Answer 19

stop smoking and reduce cardio risk (loose weight, treat hypertension etc)
close surveillance depending on size or consider surgical repair if large enough

Question 20

when is surgical repair considered in asymptomatic AAA?

Answer 20

if >5.5cm or >4cm and grown >1cm in past year

Question 21

how is asymptomatic AAA surveillanced?

Answer 21

if 3-4.4cm = yearly USS
if 4.5-5.4cm = 3 monthly USS
>5.5 = surgery

Question 22

workup for elective repair in asymptomatic AAA?

Answer 22

must do CT angiogram to know specific location

assess fitness for surgery with bloods, ECG, ECHO, pulmonary function tests, frailty score and METS

Question 23

how might a ruptured AAA present?

Answer 23

collapse
hypotension
sudden onset abdo pain radiating to back (or might just be felt in back)
expansile abdo mass +/- tenderness

Question 24

how else might a AAA present?

Answer 24

can present like renal colic (esp in men >50)
retroperitoneal fluid can cause flank pain
so beware of “renal colic” in men >50

Question 25

how is a ruptured AAA managed?

Answer 25

surgical emergency
ABCDE (get large bore IV access, send bloods, fluid resuscitation with permissive hypotension)
arrange urgent CT imaging (try and stabilise enough to get a CT before surgery)
refer to vascular surgery for open or endovascular repair

Question 26

what is permissive hypotension?

Answer 26

as long as patient is conscious (enough blood getting to brain to maintain consciousness) then you dont need to push blood and fluids in to increase BP
maintain systolic BP 70-80mmHg
if theyve made it to hospital then theyve probably formed a tamponade or clot which is keeping the bleeding at bay, if you pump lots of bloods/fluids in you could disrupt this causing massive bleed

Question 27

what happens in open repair?

Answer 27

laparotomy (open them up)
aorta clamped proximal and distal to aneurysm
aneurysm cut open and a graft inserted into aorta, aorta wall then sewn back up around graft

Question 28

what happens in endovascular repair (EVAR)?

Answer 28

repairs artery from inside using a stent graft
access from femoral artery and series of wires etc fed up into aorta under X ray guidance and stent expanded inside aorta
good for complex cases involving coeliac axis, mesenterics etc as can cover a few vessels

Question 29

complications of EVAR?

Answer 29

mainly endoleak
blood leaks through or around the graft/stent meaning the aneurysm sac can refill and rupture
might settle on it own or may need another surgery

Question 30

4 types of endoleak?

Answer 30

1 = leak due to incomplete seal
2 = back bleeding from arteries entering sac
3 = graft dysfunction
4 = porous graft material

Question 31

which is better open repair or EVAR?

Answer 31

neither strictly better
EVAR better survival at 6 months
open repair better survival at 8 years