What Are the Functions of Leeches?

Leeches are small blood-sucking worms that have been used in medicine since around 1300 BC. Leeches can grow up to 4.7 inches long, and can weigh up to .05 ounces. They have posterior and anterior suckers, each having at least 60 to 100 teeth. Leeches secrete a substance called hirudin, which promotes bleeding and prevents blood clotting. This makes them beneficial for a wide range of medical problems. Hirudin has even been synthetically reproduced to be used in hospitals when live leeches are not available.

Anticoagulant

• The hirudin secreted from leeches works as an anticoagulant while the leech is feeding. It has been used in the treatment of deep vein thrombosis, or blot clots in the veins located deep within the body. Leeches are also used to treat coronary ischemia, which is a condition caused by a lack of blood flow to the heart. Hirudin can be isolated and extracted from leech saliva. According to the Alternative Medicine Review, at least 14 different anticoagulants can be extracted from leeches.

Microsurgery

• Leeches are beneficial in microsurgery when tiny veins need to be reattached in body parts that can be challenging to work on. For example, ears and noses have small veins that require a steady hand from an expert surgeon to mend. Until the mid-1980s, attempts to reattach veins in these areas were unsuccessful. According to PBS, this changed in 1985 when a Harvard doctor successfully reattached the ear of a 5-year-old boy using leeches. Since then, leeches have been used during microsurgery on ears, noses, scalps, fingers, toes and limbs.

Post-Operative Wound Care

• Leeches are invaluable for post-operative wound care, particularly after reconstructive surgery. Leeches can relieve venous congestion in patients after breast surgery. In trauma cases, skin grafts and tissue flaps can be salvaged through the use of leeches. Leeches are placed on the skin, and led to the appropriate site by applying a sucrose solution around the wound. After feeding for about 10 to 20 minutes, the leeches will stop and remove themselves from the wound.

Other Medical Uses

• Leeches have been used to treat patients suffering from a wide range of medical issues. They have helped alleviate knee pain caused by osteoarthritis, reduce high blood pressure, and treat skin lesions such as boils or abscesses. Doctors are also discovering new ways to use leeches in treating problems of the ears, nose and throat, such as ear infections, sinusitis and abscesses in the tonsils. Topical skin creams have been manufactured using hirudin to reduce swelling in hematomas caused by trauma.