THE EFFICACY OF MEDICINAL LEECHES IN PLASTIC AND RECONSTRUCTIVE SURGERY: A SYSTEMATIC REVIEW OF 277 REPORTED CLINICAL CASES IAIN S. WHITAKER, B.A. (Hons) M.A. Cantab MBBChir, F.R.C.S., Ph.D., 1,2 * OMAR OBOUMARZOUK, M.B.B.S., M.R.C.S., 1 WARREN M. ROZEN, M.B.B.S., BMedSc, PGDipSurgAnat, Ph.D., 2 NAGHMEH NADERI, M.D., M.R.C.S., M.Sc., 1 S.P. BALASUBRAMANIAN, M.B.B.S., M.R.C.S., 1 ERNEST A. AZZOPARDI, M.R.C.S., MScSurg, M.D., 1 and MOSHE KON, M.D., Ph.D. 3 Background: Although there are numerous case reports and small case series describing the experiences of leech therapy in various cir- cumstances, there are relatively few large studies evaluating the effectiveness of leeching to relieve venous congestion. The therapeutic value of leeching is illustrated by these reports but the current literature lacks a cohesive summary of previous experiences. Methods: An electronic search of PubMed, the Cochrane library and the Centre for Reviews and Dissemination between 1966 and 2009 was used to retrieve human studies published in the English language evaluating outcomes following leech therapy. The ‘success’ and ‘failure’ of leech therapy were the primary outcome measures and secondary outcomes included complications, number of leeches used, pharmacological adjuncts and blood transfusion requirements. Results: In total, out of 461 articles, 394 articles met the exclusion criteria. The 67 included papers reported on 277 cases of leech use with an age range of 2–81 years and a male to female ratio of almost 2:1. The overall reported ‘success’ rate following leech therapy was 77.98% (216/277). In terms of secondary outcome measures, 49.75% of cases (N 5 101) required blood transfusions, 79.05% received antibiotics (N 5 166) and 54.29% received concomitant anticoagulant therapy. The overall complication rate was 21.8%. Conclusion: In the absence of robust randomized controlled trials on which the evidence may be based, this synthesis of current best evidence guides clinicians during the process of consenting patients and using leeches in their practice. V V C 2012 Wiley Periodicals, Inc. Microsurgery 32:240–250, 2012. Bloodletting and the therapeutic use of medicinal leeches dates back to ancient Egypt. 1 Decades of reports of leech therapy in plastic and reconstructive surgery 2 and more recently the application of leeching for medical prob- lems 3–6 has given Hirudo therapy a niche in contempo- rary medical practice. Plastic, 7–10 maxillofacial, 11 and other reconstructive surgeons 12,13 use leeches to aid sal- vage of compromised pedicled flaps, 2,14 microvascular free-tissue transfers 15–17 and venously congested extrem- ities including digits, 9,18–25 nipples, 26,27 ears, 28–32 lips, 33,34 nasal tips, 12,35 and the penis. 36 After many years of use, Hirudo medicinalis received official FDA ap- proval as a medical device in 2004. 37 Leeches are useful to the reconstructive surgeon, as venous anastomoses can either become compromised or are not even attempted. When anastomoses are per- formed, venous thrombosis is a more common complica- tion than arterial thrombosis 38 and it has been demon- strated in experimental flaps that acute venous obstruction is more damaging than acute and complete pedicle obstruction, where both arterial and venous supplies are involved. 39–41 There are a small number of experimental studies quantifying leech efficacy. A randomized control trial of leech treated venous compromised rodent epigas- tric skin flaps demonstrated a significant increase in flap survival rate, 42 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, quantita- tive measurements of blood flow using injected fluores- cein demonstrated an improvement of venous congestion after leech application. 43 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 microcircu- lation caused by injection of the leech’s vasoactive secre- tions. 44 Although there are numerous case reports and small case series describing the experiences of leech therapy in various circumstances, there are relatively few large stud- ies evaluating the effectiveness of leeching to relieve ve- nous congestion. 2,23,45,46 Although the therapeutic value of leeching is illustrated by these reports, the current lit- erature lacks a cohesive summary of previous experien- ces. The aim of this paper is to present current best evi- dence regarding the use of leeches by reviewing 277 cases retrieved from the literature. In the absence of ro- bust randomized controlled trials on which the evidence may be based, such a synthesis of current best evidence may serve to elucidate the efficacy of leech therapy, and 1 Department of Burns and Plastic Surgery, Morriston Hospital, Swansea, Wales, UK 2 The Taylor Lab, Room E533, Department of Anatomy and Neurosciences, University of Melbourne, Grattan St, Parkville Victoria 3050 Australia 3 Department of Plastic and Hand Surgery, University Medical Centre, Utrecht, The Netherlands *Correspondence to: Dr Iain S Whitaker, The Taylor Lab, Room E533, Department of Anatomy and Neurosciences, University of Melbourne, Grat- tan St, Parkville Victoria 3050 Australia. E-mail: iainwhitaker@fastmail.fm Received 23 January 2011; Accepted 21 September 2011 Published online 8 March 2012 in Wiley Online Library (wileyonlinelibrary. com). DOI 10.1002/micr.20971 V V C 2012 Wiley Periodicals, Inc.