Y5 - Superior vena cava obstruction

Question 1

what is superior vena cava obstruction also known as

Answer 1

superior vena cava syndrome

Question 2

most common cause

Answer 2

malignancy

Question 3

why has there been an increase in benign causes

Answer 3

due to intravascular devices

Question 4

def

Answer 4

obstruction of SVC which causes interrupted venous return from the head, thorax, and upper extremities to the right atrium

Question 5

what does increased venous pressure cause

Answer 5

oedema in the head, neck, arms, and cynosis

Question 6

aetiology

Answer 6

majority of cases are due to malignancy

Question 7

what is the most common malignancy causing SVC obstrucion

Answer 7

1 lung cancer

• non-small cell lung cancer (50%)
• small cell lung cancer (25%)

Question 8

is SVC obstruction more common on the right or left

Answer 8

right (80%)

Question 9

what are other malignancies causing SVC obstruction

Answer 9

1 lung cancer
2 lymphoma
3 thymoma

Question 10

what metastatic tumours cause SVC obstruction

Answer 10

1 breast cance
2 colon cancer
3 kaposis sarcoma

Question 11

what are benign causes of SVC obstruction

Answer 11

iatrogenic causes
-central venous catheters
-pacemakers
mediastinal fibrosis by radiotherapy or infections

Question 12

what is the most common cause of SVC obstruction

Answer 12

non-hodgkins lyphoma

Question 13

what happens to the cervical venous pressure in SVC obstruction

Answer 13

is increased to 20-40mmHg from normal range of 2-8mmHg

Question 14

what is the most important collateral venous return pathway with an obstructed SVC

Answer 14

the azygous venous system

Question 15

epi

Answer 15

increase in benign causes of SVC obstruction due to intravascular devices however malignant causes are most common
elderly males

Question 16

RFs

Answer 16

Hx of smoking
intravascular device
>50yrs

Question 17

signs and symptoms

Answer 17

oedema in face and upper extremities
dyspnoea
-worsens by bending forward or lying down
facial plethora
distended neck and chest veins

Question 18

investigations

Answer 18

CXR
-widened mediastinum or mass lesion
CT chest

Question 19

what is the most useful imaging test

Answer 19

CT chest with IV contrast

Question 20

what may be seen on a CT chest with SVC obstruction

Answer 20

full or partial obstruction

collateral vessels

Question 21

what may be found on ultrasound of upper extremities

Answer 21

dilated SVC; monophasic flow

Question 22

what is the initial investigation

Answer 22

CXR

Question 23

what is the management for acute airway obstruction in SVC obstruction

Answer 23

1 secure airway by intubation/surgery

2 radiotherapy and corticosteroids if life threatening

Question 24

what corticosteroids may be used in life threatening SVC obstruction

Answer 24

dexamethasone 10mg IV bolus plus 4mg per 6hrs

Question 25

what is the management for malignant ongoing SVC obstruction

Answer 25

treat malignancy

Question 26

what is the management for infectious causes of SVC obstruction

Answer 26

treat underlying infection

Question 27

what is the management for iatrogenic causes of SVC obstruction

Answer 27

catheters should be removed, give thrombolysis and/or anticoagulation
OR
percutaneous balloon dilatation/stenting with or without lead removal

Question 28

prevention

Answer 28

stop smoking

Question 29

complications

Answer 29

problems with percutaenous stenting

bleeding related to thrombolysis or anticoagulation

Question 30

prognosis

Answer 30

poorer prognosis for malignant causes

-non-small cell lung cancer resistant to chemo and radiotherapy has survival <6 months