The Risk-Benefit Ratio of Leech Therapy: A Single-Center Retrospective Study

Abstract

Background: Venous congestion in transplanted or replanted tissues remains a common and challenging complication of plastic and reconstructive surgery. The local application of medicinal leeches is effective in reducing postoperative venous congestion in skin flaps and restoring normal blood flow. However, leech therapy is associated with a number of risks, including infections; in order to digest blood, leeches have a symbiotic relationship with Aeromonas species in their gut. Aeromonas infections are associated with a dramatic decrease in flap salvage rates. This is why prophylactic antibiotic treatment and external decontamination of the leeches are widely recommended. Methods: We performed a single retrospective study of patients having undergone leech therapy between January 1st, 2010, and December 31st, 2018, at Amiens-Picardie University Hospital, France. Each patient’s medical history, clinical data, laboratory results, prophylactic antibiotic use, and complications were recorded.Results: A total of 37 patients (mean age: 47) had undergone leech therapy after reconstructive surgery. Antimicrobial prophylaxis was documented in 32 (84.6%) patients. However, there are no guidelines on the choice of prophylactic antibiotic treatment. Twenty-four of the 37 (64.8 %) patients had anemia (mean hemoglobin level: 8.5 (6-11.1) g/dL), and 13 of the 24 (54%) required a transfusion. Thirteen of the 37 patients (35.1%) had a post-operative infection mainly due to Aeromonas spp. (76.9%). Leech therapy was effective in 23 of the 37 patients (62%) overall and in 2 of the 10 patients (20%) with an Aeromonas infection. The association between Aeromonas infection and flap salvage failure was highly significant (p = 0.005).Conclusions: The results of the study emphasized that clinical bacteriologists and surgeons should be aware that leeches are potential sources of infection.