Is the use of intraoperative heparin safe?

Despite the reliability of microvascular free tissue transfer, flap loss remains a significant concern. To improve outcome, various pharmacologic agents have been used to prevent microvascular thrombosis. The authors review their experience with intraoperative heparin therapy, specifically addressing the risks of hematoma, pedicle thrombosis, and flap loss rate.

Results from consecutive free flaps performed over a 3-year period were reviewed using a prospectively maintained database. Patients were divided into two groups: group A received a bolus of 3000 units of intraoperative heparin 10 minutes before flap pedicle ligation; group B did not receive intraoperative heparin. Patient demographics, procedure type, diagnosis, adjuvant treatment, and complications were recorded. Outcome variables included microvascular thrombosis, total and partial flap loss, hematoma, seroma, pulmonary embolism, and death.

Four hundred seventy patients underwent 505 microvascular free flaps for reconstruction of oncologic defects. Reconstructed areas included head and neck (n = 288), trunk and breast (n = 151), upper extremity (n = 12), and lower extremity (n = 19). Of these, 260 flaps (group A) received an intraoperative heparin bolus, and 245 flaps (group B) received no intraoperative heparin bolus. There were no statistically significant differences in major and minor complications between the two groups (power = 0.85).

Intraoperative systemic heparin use has no statistically significant effect on the incidence of microvascular thrombosis. In addition, administration of a single dose of intraoperative heparin does not increase the rate of hematoma formation or prevent microvascular thrombosis. Thus, critical factors for flap survival are likely independent of the use of intraoperative anticoagulation.