P048: UNUSUAL HEMATOMA REQUIRING THYROMENTAL ARTERY COILING AFTER A SUPRACLAVICULAR BLOCK
Joseph Prunier, DO1; Nicholas Farrat, MD1; Heine Rivera-Rodriguez, MD1; Jose Rivera-Melendez, MD1; Eugenio Oliveros, APRN2; Suvikram Puri, MD1; Enrico M Camporesi, MD1; Jason Udani, MD1
1University of South Florida Morsani College of Medicine; 2TeamHealth Anesthesia, Tampa General Hospital
We report a case of supraclavicular hematoma formation with subsequent pseudoaneurysm development following an ultrasound-guided supraclavicular nerve block. An 84-year-old male with end-stage renal disease (ESRD) on hemodialysis, coronary artery disease (CAD), congestive heart failure (CHF), atrial fibrillation, and hypertension presented for scheduled creation of a right upper-extremity arteriovenous fistula (AVF). He had received dialysis the day before. Laboratory studies revealed thrombocytopenia (platelet count 86 × 10³/µL) with all other coagulation parameters within normal limits. The patient was not receiving anticoagulation for atrial fibrillation owing to a prior gastrointestinal bleed while on warfarin.
A supraclavicular nerve block was performed in the pre-operative area for primary anesthesia and postoperative analgesia. The block was performed under US guidance with standard ASA monitors. No pulsatile vessels were visualized other than the subclavian artery. Ropivacaine 0.5% was injected incrementally in 5-mL aliquots with negative aspiration before each injection. The patient reported no paresthesia and remained hemodynamically stable throughout the procedure.
Forty-five minutes after the injection, the patient was transferred to the operating room with the previous block site clean, dry, and intact. Upon positioning, significant swelling was noted in the right supraclavicular area. An immediate bedside ultrasound, performed with a vascular surgeon present, showed no extravasation or pulsatile flow other than that of the subclavian artery. A pressure dressing was applied, and the surgery was canceled due to concern for venous arterialization. The patient was observed in the PACU; after six hours, he remained stable, with no evidence of an expanding hematoma, and was discharged with close follow-up.
Four hours after discharge, the patient returned to the emergency department with new firmness and pain in the right supraclavicular region that worsened on head rotation to the right. He exhibited no motor or sensory deficits, and his vital signs were normal. Repeat laboratory studies showed a platelet count of 78 × 10³/µL. Computed tomography angiography of the neck demonstrated a "large right supraclavicular hematoma measuring 9 × 7 × 7 cm with a focal area of contrast blush suggestive of pseudoaneurysm formation".
On post-block day 5, diagnostic cerebral angiography identified a large pseudoaneurysm arising from a distal branch of the thyrocervical trunk. The lesion was successfully treated with embolization using Onyx and detachable coils, followed by percutaneous thrombin injection under ultrasound guidance. The patient tolerated the procedure well and was discharged the following day with no further complications. We suspect that the relative thrombocytopenia may have contributed to this event.
