Leech Therapy Can Save Previously Unsalvageable Tissue Transplants

Website: http://www.sic2004.org/

Newswise — In July 2004, the nation's media reported that the Food and Drug Administration (FDA) issued its first ever medical device approval for a live animal " leeches (and maggots). That report explained how leeches can help revive the health of human tissue when modern medical techniques fail. Now, researchers have long term follow-up data that supports the claim that leech therapy can save head and neck cancer patients from undergoing a second major reconstructive surgery.

Historical evidence exists that leeches were used medicinally more than 2,500 years ago as evidenced by their appearance in wall-paintings depicting withdrawal of blood found in the era of the Egyptian pharaoh, King Tut. Today, these bloodsucking annelid worms have been approved by the FDA as a last-ditch effort to restore blood flow in failing head and neck reconstruction cases.

Surgery for oral and head and neck tumors often involves the removal of tissue that leaves a large hole in the face, mouth or throat requiring major reconstructive surgery, which takes an average of 12 hours. One such method of reconstruction is the use of "free flaps," or tissue from another part of the patient's body that is transplanted into the affected area. Though the success rate for free flaps is quite high, if blood flow between the transplanted skin and new location cannot be established (venous obstruction), additional surgery may be required to initiate blood flow. In a few cases, venous obstruction persists and blood cannot flow. At that point, the transplant is considered unsalvageable and the tissue dies, necessitating a second transplant surgery. Leech therapy presents an alternative for these cases that allows patients to avoid another transplant surgery. By attaching to the transplanted tissue, the leeches drain out blood, which maintains blood flow and keeps the tissue alive.

In the August 2002 edition of Archives of Otolaryngology " Head and Neck Surgery, head and neck cancer researchers introduced a leech therapy protocol that was successful in saving previously unsalvageable free flap failures. Long term follow-up of this research provides additional findings showing that leech therapy can benefits for restoration of head and neck free flap reconstructions determined to be unsalvageable. The updated findings of "Leech Therapy for the Salvage of Revascularized Free Tissue Transfer with Venous Obstruction" will be presented by authors Douglas B. Chepeha, MD, Brian Nussenbaum, MD, Carol R. Bradford, MD, and Theodoros N. Teknos, MD, of the Department of Otolaryngology, University of Michigan Health System, Ann Arbor, at the 6th International Conference on Head and Neck Cancer (http://www.sic2004.org) being held August 7-11, 2004, at the Wardman Park Marriott in Washington, DC.

Methodology: From January 1, 1995 to April 1, 2004, 700 head and neck free tissue transfers were done. Out of these cases, 15 patients developed flap failure, as a result of venous obstruction that was deemed unsalvageable. These patients, nine men and six women (median age 54 years, range 21 to 79 years) received leech therapy after their venous outflow obstruction was determined unsalvageable by surgery or thrombolytic therapy (medication to dissolve blood clots). Leech therapy with the Hirudo medicinalis species of leech was provided to ten patients extraorally (outside the mouth) and four patients intraorally (inside the mouth), while one patient received the therapy both intraorally and extraorally. The patients were measured for flap salvage rate, number of leeches used per patient, time needed for inosculation (tissue cohesion), duration of intensive care unit admission, transfusion requirement per patient, and complications during leech therapy.

Results: The leech treatment was successful in restoring blood flow and ensuring survival of all 15 free flap reconstructions (eight totally, seven partially). The average number of leeches used per patient was 270 (ranging from 80-672 leeches) and the average time for the leeching program was 6.9 days (range three to 16 days). The average for the intensive care unit monitoring was 9.9 days (range four to 18 days). The transfusion requirement per patient was 13 U (units) of packed red blood cells (range five to 62 U), with no substantial transfusion related problems. The complications that developed were: intensive care unit psychosis in five patients, prerenal azotemia (an excessive level of nitrogen-type wastes in the blood) in four patients, and congestive hear failure, pneumonia, decubitus ulcer (bed sore), and non-Aeromonas wound infection, in one patient each.

Conclusion: Leech therapy continues to be an effective method of salvaging venous obstruction flap failure when surgery and other treatment options fail, saving patients from a second reconstructive surgery and providing positive long term results. As with any therapy, the risks involved must be examined before undertaking leech therapy, therefore the authors recommend judicious application of this protocol.