Background Medicinal leech therapy is used for the salvage of tissue flaps failing because of venous congestion. Leeches secrete hirudin, an anticoagulant and a histamine-like vasodilator that promotes re-establishment of capillary growth. Intraoral medicinal leech therapy is useful in reconstructive surgery but poses specific challenges. There are few publications on intraoral leech therapy, and no specific intraoral protocol has been established.

Objectives The purpose of this study was to present our experience of intraoral leech therapy with review of the relevant literature and to propose a protocol specific for intraoral leech therapy.

Case Report A female patient with intraoral squamous cell carcinoma underwent resection, bilateral neck dissection and reconstruction with a radial forearm free flap. Post-operatively she developed a venous clot and then a hematoma both requiring revision surgeries. She consequently developed venous congestion requiring intraoral leech therapy. 

Methods A literature review was conducted in several medical databases. Search terms used were medicinal leech therapy, free flaps, venous congestion, head and neck reconstruction.  

Principle Findings/Discussion Intraoral leech therapy is challenging for several reasons; limited space of the oral cavity, potential for migration down the aerodigestive tract; anchorage of leeches to specific intraoral sites and the need for intubation and sedation.  As a result, this treatment is labour-intensive and highly operator dependant. We propose a protocol specific for intraoral leech therapy that includes pre-operative patient counseling, identifying suitable patients for leech therapy, methods of securing accurate attachment, preventing leech migration, number of leeches and duration of therapy and objective monitoring of progress. Also, we suggest training of nursing and medical staff in leech therapy in specialised head and neck units.

Conclusion Medicinal leech therapy is useful for the salvage of venous congested intraoral free flaps. The effectiveness of this therapy can be improved with a evidence-based protocol specific for the oral cavity.