Venous congestion in transplanted or re-implanted tissues remains a common and chal-lenging complication in plastic and reconstructive surgery. Local application of medicinal leeches is effective to reduce postoperative venous congestion of the flap and to restore normal blood flow. However, leech therapy is associated with a number of risks, including infections. Indeed, leeches maintain a symbiotic relationship with Aeromonas species in order to digest blood in their gut. Aeromonas spp. infections can occur 1 to 30 days post-application of leeches and are associated with a dramatic decrease in flap salvage rates (88 to 30%). For these reasons, prophylactic antibiotics and, external decontamination are widely recommended throughout the course of leech therapy.

The aim of this study is to investigate the prevalence of side effects (anemia and infection) from patients treated with leeches in French Hospital.

Inclusion Criteria:

• Patient who received leeches (for more than 2 days) at the Amiens University Hospital over a period of 9 years (2010-2018)

Exclusion Criteria:

• Hirudotherapy outside the inclusion period
• Hirudotherapy or less than 2 days of treatment

Patient who received leeches (for more than 2 days) at the Amiens University Hospital over a period of 9 years (2010-2018)