(946) Trading Leeches for Intradermal Bivalirudin for Threatened Free Flaps

Introduction: Free flaps are utilized in reconstruction for defects created during surgery. Due to the manipulation of blood vessels, venous congestion is a potential complication. Treatments for this include surgical reintervention, systemic anticoagulation, or leeches; but local bivalirudin injected into the flap has also been investigated. This method gives the opportunity to forgo the OR, widespread systemic anticoagulation exposure and avoids the potential infectious associated with leeches. Bivalirudin is a direct thrombin inhibitor that works in a similar way to hirudin in leeches saliva. A previous study utilized bivalirudin 0.3 mg/kg intradermally of the free flap. This was found to have success, with only 2 of 10 patients requiring additional. This practice was implemented at our academic medical center and we sought to understand the efficacy.

Methods: A retrospective, single-center, cohort review of head and neck surgical patients who received intradermal bivalirudin. The primary outcome was the need to return to OR within 72 hours of bivalirudin administration. Secondary outcomes include need for blood transfusion, the percent decrease in hemoglobin and increase in APTT and need for additional operative intervention. Due to the small number of patients, only descriptive statistics were performed.

Results: From January 1, 2024 when the bivalirudin protocol was put into place, there have been 4 courses of intradermal bivalirudin utilized for 3 patients. The most common type of free flap utilized was anterolateral thigh (ALT) flap. Doses were 0.3mg intradermal either every 6 hours or every 8 hours. 2 patients required operative intervention within 72 hours of bivalirudin use. The average hemoglobin was 9 g/dL and dropped on average 20.1% while the APTT baseline was on average 32.5 seconds and increased on average 53%. Patients required an average of 3 packed red blood cells while receiving bivalirudin.

Conclusions: At this time, intradermal bivalirudin appears to be safe to utilize in head and neck free flap patients with monitoring of CBC and APTT while on therapy. Data collection of additional patients is needed to draw any significant conclusions. This therapy, if effective, has the potential for flap patients to need a reduced amount of time in the ICU.