Week 21 - Aneurysms, Ischaemic Limb, occulsions, arterial thrombosis, DVT

Question 1

what is an aneurysm

Answer 1

is an artery that has a localised dilation, with a permanent diameter of >1.5x that expected of the particular artery

Question 2

what is a false aneurysm

Answer 2

other surrounding tissues form the wall of the aneurysm

Question 3

where do pseudoaneurysms most commonly occur

Answer 3

in the femoral artery following a femoral artery puncture.

if there is inadequate pressure to the entry site of the puncture, then blood can spill out and form a haematoma. eventually the surrounding soft tissue will form the wall of the aneurysm

Question 4

what is the difference between a psuedo and real aneurysm

Answer 4

the difference is that in a pseudoaneurysm there is still communication between the lumen and the fluid collection, but in a haematoma, there is either no connection or just a one way ‘leakage’ of fluid

Question 5

what are the the two shapes of aneurysm

Answer 5

fusiform and sac-like

Question 6

what is a fusiform aneurysm

Answer 6

describes a shape that is tapered at both ends (a bit like a raindrop with a pointy bit at both ends)

Question 7

what is a sac like aneurysm

Answer 7

describes a more rounded characterisitc

Question 8

what are the risk factors for aneurysmal disease

Answer 8

Hypertension
Smoking
Age
Diabetes
Obesity
High LDL levels
Sedentary lifestyle
Genetic factors – are more important in aneurysmal disease than in atherosclerotic disease, although they have a role in both.
10% of cases have a first-order relative also with the condition

Question 9

what is the main risk of aneurysms

Answer 9

they have a tendency to dissect and rupture

Question 10

where does an aortic aneurysm most commonly rupture into

Answer 10

the retroperitoneal space

Question 11

what is used to ‘stage’ the aneurysm

Answer 11

ultrasound

it is accurate at assessing the site of the aneurysm, and easy to follow up cases to assess development

Question 12

an aortic aneurysm of what size should be treated

Answer 12

an aneurysm that is greater than 5.5cm

Question 13

what is thought to be a risk for rupture in an AAA

Answer 13

pain

Question 14

what is an open laparotomy

Answer 14

the affected segment of aorta may be clamped and replaced by a prosthetic segment

Question 15

what is the most common graft done in an open lapraotomy

Answer 15

a Dacron graft

Question 16

what is EVAR

Answer 16

Endoluminal surgery – EVAR – Endovascular aneurysm repair

n aortic graft is inserted through the femoral artery, and up into the abdominal aorta. This method is generally preferred (lower mortality 1.2%) but many patients are not suitable. There must be at least 2.5cm normal aorta between the aneurysm and the renal arteries to securely fix the graft in place.

Question 17

when does acute limb ischaemia happen

Answer 17

when there is a blockage of a peripheral artery, either from a thromboembolism, or sometimes from an embolic plaque

Question 18

As the MI is to coronary artery disease, acute limb ischaemia is to peripheral vascular disease

Question 19

what are the classic 6 P’s of acute limb ischaemia

Answer 19

Pulseless
Paraesthesia
Pain – muscles also become tender to palpation after about 6-8hours
Paralysis
Pallor
Perishing cold

Question 20

what is seen on the skin in acute limb ischaemia that implies irreversibility

Answer 20

fixed mottling

Question 21

how is diagnosis of acute limb ischaemia given

Answer 21

you can roughly localise the blockage by locating the bifurcation distal to the last palpable pulse

diagnosis is clinical

Question 22

what percentage of cases of ACI are fatal

Answer 22

22%

Question 23

what is given via the local arterial catheter in acute limb ischaemia

Answer 23

tissue plasminogen activator - thrombolytic agent

Question 24

what can reperfusion injury lead to

Answer 24

compartment syndrome

Question 25

where are the common sites for occlusion

Answer 25

splanchnic arteries superior mesenteric coeliac arteries renal arteries bifurcation of the aorta

Question 26

what are the signs of renal artery occlusion

Answer 26

sudden onset flank pain haematuria

Question 27

what test should you perform on all suspected ischaemic bowel patients

Answer 27

lactate - normal lactate makes the condition unlikely

Question 28

where does the thrombus travel in a DVT

Answer 28

travels from the deep veins, through the right side of the heart and into the lungs, where it becomes lodged in the pulmonary arteries

Question 29

what happens when a DVT travels to the pulmonary arteries

Answer 29

it blocks blood flow to areas of the lungs and this is called a PE

Question 30

what happens if the patient has a hole in their heart

Answer 30

the blood clot can pass through the left side of the heart and into the systemic circulation. it can travel to the brain and cause a large stroke

Question 31

what are thrombophilias

Answer 31

conditions that predispose patients to develop blood clots

Question 32

what are examples of thrombophilias

Answer 32

Antiphospholipid syndrome Factor V Leiden Antithrombin deficiency Protein C or S deficiency Hyperhomocysteinaemia Prothombin gene variant Activated protein C resistance

Question 33

if you can remember one cause of recurrent VTE what should it be

Answer 33

antiphospholipid syndrome. the common association you may come across in exams is recurrent miscarriage. the diagnosis can be made with a blood test for antiphopholipid antibodies

Question 34

what is VTE prophylaxis usually in the hospital

Answer 34

low molecular weight heparin such as enoxaparin

Question 35

what are the contraindications for VTE prophylaxis

Answer 35

active bleeding or existing anticoagulation with warfarin or a DOAC

Question 36

what is the main contraindication for anti-embolic compression stockings

Answer 36

peripheral arterial disease

Question 37

how does one examine for leg swelling

Answer 37

measure the circumference of the calf 10cm below the tibial tuberosity. more than 3cm difference between calves is significant

Question 38

what is the scoring system used to predict risk of patient who is presenting with symptoms of having a DVT or PE

Answer 38

the Wells score it includes risk factors such as a recent surgery, clinical findings such as unilateral calf swelling 3cm greater than the other leg

Question 39

what is required to diagnose DVT

Answer 39

doppler ultrasound of the leg NICE recommends repeating negative ultrasound scans after 6-8 days if a positive D dimer and Well's score suggest a DVT is likely

Question 40

what is initial management of a suspected or confirmed DVT or PE

Answer 40

starts with anticoagulation

Question 41

what are two examples of anticoagulation

Answer 41

apixaban or rivaroxaban

Question 42

what do NICE recommend considering for patients with a symptomatic iliofemoral DVT and symptoms lasting less than 14 days

Answer 42

catherter-directed thrombolysis

Question 43

what are the options for long term anticoagulation in VTE

Answer 43

DOAC, warfarin or LMWH

Question 44

what are DOACs

Answer 44

oral anticoagulants that do mot need monitoring

Question 45

give four examples of DOACs

Answer 45

apixaban rivaroxaban edoxaban dabigatran

Question 46

what is warfarin

Answer 46

a vitamin K antagonist

Question 47

what is the target INR for warfarin when treating PEs and DVTs

Answer 47

between 2 and 3

Question 48

in which patients is warfarin first line

Answer 48

in patients with antiphospholipid syndrome

Question 49

what is the first line anticoagulant in pregnancy

Answer 49

LMWH

Question 50

how long do you continue anticoagulation if there is a reversible cause

Answer 50

3 months

Question 51

how long do you continue anticoagulation if the cause is unclear, there is a recurrent VTE, or there is an irreversible underlying cause such as thrombophilia

Answer 51

beyond 3 months

Question 52

how long do you continue anticoagulation for in patients with active cancer

Answer 52

3-6 months

Question 53

what are inferior vena cava filters

Answer 53

devices inserted into the IVC, designed to filter the blood and catch any blood clots travelling from the venous system, towards the heart and lungs they act as a sieve, allowing blood to flow through whilst stopping larger blood clots

Question 54

when are inferior vena cava filters used

Answer 54

in unusual cases of patients with recurrent PEs or those who are unsuitable for anticoagulation

Question 55

what is investigated when patients have their first VTE witihout a clear cause,

Answer 55

NICE guidlines recommend reviewing the medical history, baseline blood results and physical examination for evidence of cancer