Lecture 8 Lymphedema: Pathophysiology & Diagnosis

Question 1

Primary vs. Secondary Lymphedema

Answer 1

• Primary: Absence/decrease of lymphatic vessels
• Secondary: acquired through cancer, trauma, and infection

Question 2

Primary Lymphedema: Aplasia

Answer 2

• missing function of lymphatic system

Question 3

Primary Lymphedema: hypoplasia

Answer 3

• not enough lymphatic system

Question 4

Function of the lymphatic system

Answer 4

1. absorption and transport of lymph assists venous circulation
2. Immunological
3. Digestion

Question 5

what is the percentage of interstitial fluid that lymph system & venous system collects?

Answer 5

• Lymph system collects 10-20%
• Venous system collects 80-90%

Question 6

How are the Lymphatics run to the circulatory system?

Answer 6

• Parallel

Question 7

Fluid pathway of Lymphatic System

Answer 7

• unidirectional flow only toward heart

Question 8

Superficial and deep pathways of Lymphatic system

Answer 8

Interstitial spaces > Lymphatic capillaries > Pre-collectors > Collectors > Lymph nodes > Trunks > Ducts > Venous angles (subclavian veins) > Venous circulation

Question 9

Where are lymph vessels not fond

Answer 9

• Brain and Spinal Cord

Question 10

Lymphatic Capillaries

Answer 10

• no valves, lymph can flow in any direction
• allow us to manipulate the drainage pathway
• Main function = Absorption

Question 11

Collectors

Answer 11

• Have valves: unidirectional
• “micro hearts”
• Function = Transport

Question 12

Function of Lymph nodes

Answer 12

• Produce lymphocytes
• Trap foreign matter
• Regulates fluid volume

Question 13

Function of the ducts

Answer 13

• Empty lymph fluid into the blood circulation at the right and left venous angles

Question 14

Thoracic Duct

Answer 14

• drains 75% of the body’s lymph fluids
• Starts around L2 level

Question 15

Right Lymphatic Duct

Answer 15

• drains 25% of the body’s lymph fluid

Question 16

Major watershed area

Answer 16

• Mid sagittal
• transverse
• calvicular
• spine of scapula
• gluteal

Question 17

Function of Anastamoses

Answer 17

• allow for fluid exchange

Question 18

What are the regional lymph node groups

Answer 18

Axillo-axillary
Interinguinal
Axillo-Inguinal

Question 19

Fluid Transport out of capillaries

Answer 19

• Arterial Side
  -Blood Capillary pressure (BCP)
• Colloid osmotic pressure interstitiel (COPi)

Question 20

Fluid transport into capillaries

Answer 20

• Venous side
• Interstitial Pressure
• Colloid Osmotic Pressure Plasma (COPp)

Question 21

Starling’s Law: fluid balance is even

Answer 21

BCP = COPp

Question 22

Starling’s Law: Arterial

Answer 22

BCP > COPp = Ultrafiltration

Question 23

Starling’s law: Venous

Answer 23

BCP < COPp = Reabsorption

Question 24

Lymphatic Transport

Answer 24

• No central pump or heart equivalent

Question 25

Lymphatic fluid is transported via

Answer 25

- intrinsic contractions - Lymph volume - Skeleteal muscle contraction * Ankle Pump - Arterial pulsation - Respiratory pressure changes - External pressure

Question 26

Lymphedema defined

Answer 26

- Abnormal accumulation of protein rich fluid causing chronic inflammation and reactive fibrosis

Question 27

Pathophysiology of Lymphedema

Answer 27

Reduced lymph transport capacity > Mechanical insufficiency & less protein absorbed > Increased protein draws more fluid out of capillaries > increasing ultrafiltration > edema

Question 28

Lymphedema leads to

Answer 28

Increase in infection risk

Question 29

Primary Lymphedema is caused by?

Answer 29

- Lymphatic dysplasia - More often in females and in the Lower extremities

Question 30

Milroy's disease is a form of?

Answer 30

- Primary lymphedema

Question 31

Secondary Lymphedema can be caused by?

Answer 31

- filariasis, cancer, trauma, infection, surgery, radiation, CVI

Question 32

Highest risk to develop Breast cancer-related lymphedema?

Answer 32

- ALND + radiation therapy (Axillary lymph node dissection)

Question 33

What is something to be aware of BCRL?

Answer 33

- Typically occurs within 1 year of cancer treatment but can develop years after

Question 34

What does Limb Alert mean?

Answer 34

- no blood pressure & No IVs

Question 35

Clinical Characteristics of both types

Answer 35

- starts distally - pitting in early stages - fibrosis in mid stages - skin changes in later stages - positive stemmer signs - rarely painful

Question 36

How does Lymphedema progress through the stages

Answer 36

- progressive, but no consistent pattern

Question 37

Stage 0

Answer 37

- transport capacity reduced - no real objective differences - no edema detectable

Question 38

Stage 1

Answer 38

- Accumulation of protein rich fluid - Pitting may be present - reduces with elevation - no fibrosis

Question 39

Stage II

Answer 39

- Constant girth increase - Pitting & fibrosis present - elevation doesn't reduce swelling

Question 40

Stage III

Answer 40

- Non Pitting edema (fibrosis) - skin changes: thickening, hyperpigmentation, increased skin folds, fat deposits

Question 41

Positive Stemmer's sign

Answer 41

- dorsal skin of the second toe/finger can't be easily lifted away from the bone

Question 42

3 main tissue texture

Answer 42

- soft - spongy - firm

Question 43

Girth Measurements

Answer 43

Mild: < 3 cm difference between affected and unaffected limbs Moderate: 3-5cm difference between affected and unaffected limbs Severe: > 5cm difference