Informed Consent Forms
Template and checklist for hirudotherapy informed consent
Last updated: March 14, 2026
Legal Requirement
Required Disclosures
Nature of Procedure
- Application of live, FDA-cleared medicinal leeches (510(k)-cleared medical device)
- Each leech creates a Y-shaped bite wound and feeds for 20-45 minutes
- Prolonged bleeding (typically 4–24 hours, occasionally longer in anticoagulated patients) is an expected therapeutic effect, not a complication
Common Side Effects
- Localized itching at bite site (37-75% of patients)
- Regional lymphadenitis (6-13% of patients)
- Mild-to-moderate blood loss per session
- Residual Y-shaped scar at each bite site (~2-3 mm)
- Mild stinging at bite initiation (resolves in 1-2 min)
Serious Risks
Aeromonas Infection
7-20% of treatment courses without prophylaxis, <5% with prophylaxis. Aeromonas hydrophila and related species are obligate symbionts of the leech gut. Infection may manifest up to 26 days after treatment. One documented case of lethal sepsis (A. veronii). Aeromonas meningitis has been reported. Cases of fluoroquinolone-resistant infection have been published.
Other Serious Risks
- Blood loss requiring transfusion: 49.75% of microsurgical patients require transfusion (Whitaker et al., 2012)
- Allergic reaction: Rare; ranges from localized urticaria to anaphylaxis
- Treatment failure: ~78% flap salvage rate; 22% may require resection despite therapy. Infection reduces salvage to 37.4%
Off-Label Disclosure
Mandatory for Non-Surgical Uses
For any use beyond the FDA-cleared indications (venous congestion in grafts, flaps, and replanted tissues), the consent form must explicitly state:
- The proposed use is off-label
- The FDA has not evaluated safety or effectiveness for the specific condition
- Available evidence may be limited
- The patient understands and accepts the off-label nature of the treatment
Antibiotic Prophylaxis Disclosure
Standard of Care Requirement
The consent process must inform the patient that prophylactic antibiotic therapy is part of the standard of care. Patient refusal of prophylactic antibiotics is grounds for withholding leech therapy (Mumcuoglu et al., 2014). This must be documented as a condition of treatment.
Consent Form Checklist
A Compliant Consent Form Must Include:
- ☐ Patient name, date, treating practitioner
- ☐ Diagnosis and clinical indication
- ☐ FDA clearance status (510(k)-cleared, product code NRN)
- ☐ Off-label status disclosure (if applicable)
- ☐ Procedure description (number of leeches, sites, duration)
- ☐ Common side effects (itching, lymphadenitis, bleeding, scarring)
- ☐ Serious risks (Aeromonas % range, blood loss, allergy)
- ☐ Prophylactic antibiotic requirement (drug, dose, duration)
- ☐ Alternatives to leech therapy
- ☐ Right to withdraw consent at any time
- ☐ Contraindication screening acknowledgment
- ☐ Patient signature, practitioner signature, date
Witness signature is recommended but not universally required.
Alternatives Section
Treatment Alternatives to Disclose
- Heparin-soaked gauze/pledgets (chemical leeching)
- Surgical revision of venous anastomosis
- Hyperbaric oxygen therapy
- Negative pressure wound therapy
- Observation and conservative management