Heparin-induced thrombocytopenia in lower extremity free tissue transfers.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) an immunologically mediated reaction to heparin products, can lead to severe thrombocytopenia and potentially life-threatening thrombotic events. In microsurgery, a missed or delayed diagnosis of HIT can cause complications requiring revision operations, flap loss, or limb loss. Surgeons must remain vigilant for this uncommon yet potentially devastating condition and keep abreast of management strategies. METHODS: CPT and ICD-10 codes in electronic medical records were used to collect demographic information, clinical courses, and outcomes for patients with a HIT diagnosis who underwent lower extremity free tissue transfer in one institution. RESULTS: The authors' institution performed 415 lower extremity free flaps in 411 patients during the 10-year study period. Flap salvage rate was 71% for compromised lower extremity flaps without HIT, and 25% in those with HIT. Four patients (four flaps) met study inclusion criteria during the study period. Three of the four flaps failed and were later debrided; one was rescued after a takeback for anastomosis revision. Two patients successfully underwent a delayed second free flap procedure after recovery, and one was salvaged with a pedicled muscle flap. CONCLUSIONS: Surgeons should monitor for HIT by establishing coagulation panel and platelet count baselines and trending these values in the early post-operative period for patients treated with heparin products. The 4T score can be used to screen for HIT with high clinical suspicion. Arterial thrombosis or poor flap perfusion despite sound microvascular technique could suggest HIT. Surgical and medical management including strict heparin avoidance can prevent adverse events for these patients.

A Case for a Local Flap as Primary Reconstruction for Hidradenocarcinoma of the Leg.

Hidradenocarcinomas are rare, aggressive sweat gland tumors typically occurring in the scalp and upper extremities. They have rarely been described in the lower extremity. Due to their rarity, there is little consensus on optimal adjuvant therapy for these tumors after resection. Regardless, it is important to plan tumor excision and subsequent reconstruction with adjuvant therapy in mind. This case report describes a patient for whom a local muscle flap with skin graft provided adequate wound coverage after excision of hidradenocarcinoma and negative-pressure wound therapy. The surgical site then withstood adjuvant radiation therapy. When radiation is planned to a wound bed after tumor excision, a local muscle flap is the excellent first choice over skin graft alone regardless of wound bed characteristics.