Leeches and Maggots in Wound Healing

Question 1

Describe how maggot therapy work (4 key points)

Answer 1

1. Maggots debride (clean) wounds by dissolving dead, infected tissue
2. Maggots disinfect the wounds by killing bactera (even when antibiotics are ineffective). N.B. They’re more effective at killing gram +’ve bacteria
3. Maggots prevent further infection of wound
4. Maggots actively promote wound healing

Question 2

Explain the 2 ways in which maggots can be applied in therapy

Answer 2

1. Free-range larvae applied directly to the wound (Good for large wounds)
2. Contained larvae dressings (preferred by patients but less effective)

Question 3

How are free-range maggots applied? (6 steps)

Answer 3

1. Barriers are applied to protect the surrounding skin - because maggots only eat dead skin and secrete stuff which can irritate normal skin
2. Apply maggots to wound
3. Cover with a moist swab and perforated film dressing
4. Leave for 3-4 days
5. Dispose of use dressings via clinical waste
6. Wash maggots from wound (discard in clinical waste)

Question 4

What wounds cannot be treated with maggots? (2)

Answer 4

1. Dry wounds (but a moist gauze swab may be sufficient to provide moisture)
2. Wounds in body cavities

Question 5

What factors influence the effectiveness of maggot therapy? (3)

Answer 5

1. Age (less effective if >60 years old)
2. Influenced by type of wound (less effective on non-traumatic wounds or deeper wounds)
3. Less effective in chronic limb ischaemia

Question 6

Why consider maggot therapy over conventional therapy? (4)

Answer 6

1. Difficult to treat or wounds unresponsive to conventional treatments
2. Maggots have been shown to clean wounds more quickly than conventional dressings
3. maggots can aid the management of infected wounds through anti-bacterial secretions
4. Faster healing times achieved with maggot therapy - can benefit patient and can also be cost effective

Question 7

What are the benefits of leeches in microsurgery? (3)

Answer 7

1. Drains blood from congested sites
2. relieves building pressure
3. prevents blood clotting in small veins in graft

Question 8

A substance in leech saliva includes ‘hirudin.’ What does it do?

Answer 8

Hirudin is an anti-coagulant in leech saliva.

It prevents blood from clotting by binding to and inactivating thrombin, thus inhibiting the conversion of fibrongen to fibrin

Question 9

Explain the steps to apply leeches (4)

Answer 9

1. clean the patient’s skin thoroughly with soap and water, then rinse with destilled water (leeches don’t like strong odor)
2. place a dampened square of gauze on the area to be treated (to prevent them wondering off)
3. choose a hungry leech
4. attachment occurs generally quickly. If not, produce a tiny droplet of blood with a needle prick

Question 10

What is the main safety consideration with leeches? (1)

Answer 10

1. Infection is the main complication (as leeches aren’t sterile)