The efficacy of medical leeches in plastic and reconstructive
November 4, 2015
Bloodletting and the therapeutic use of medicinal leeches dates back to ancient Egypt. Decades of reports of leech therapy in plastic and reconstructive surgery and more recently the application of leeching for medical problems has given Hirudo therapy a niche in contemporary medical practice. Plastic, maxillofacial, and other reconstructive surgeons use leeches to aid salvage of compromised pedicled flaps, microvascular free-tissue transfers and venously congested extremities including digits, nipples, ears, lips, nasal tips, and the penis. After many years of use, Hirudo medicinalis received official FDA approval as a medical device in 2004.
Leeches are useful to the reconstructive surgeon, as venous anastomoses can either become compromised or are not even attempted. When anastomoses are performed, venous thrombosis is a more common complication than arterial thrombosis and it has been demonstrated in experimental flaps that acute venous obstruction is more damaging than acute and complete pedicle obstruction, where both arterial and venous supplies are involved. There are a small number of experimental studies quantifying leech efficacy. A randomized control trial of leech treated venous compromised rodent epigastric skin flaps demonstrated a significant increase in flap survival rate, and in a leech treated porcine model of venous compromised flaps, improved blood flow was objectively demonstrated using laser Doppler perfusion monitoring. In a case of human ear replantation, quantitative measurements of blood flow using injected fluorescein demonstrated an improvement of venous congestion after leech application. The increased blood flow found throughout the leech treated flap is thought to be due to a combination of bleeding relieving obstruction and thus capillary pressure, and also by effects on the microcirculation caused by injection of the leech’s vasoactive secretions. Although there are numerous case reports and small case series describing the experiences of leech therapy in various circumstances, there are relatively few large studies evaluating the effectiveness of leeching to relieve venous congestion. Although the therapeutic value of leeching is illustrated by these reports, the current literature lacks a cohesive summary of previous experiences.