Mohs Surgery for Recurrent Auricular Squamous Cell Carcinoma on Apixaban
A 72-year-old man is referred for Mohs micrographic surgery of a recurrent 1.8 cm squamous cell carcinoma on the left helix. He had a previous excision two years ago with positive margins. He takes apixaban for atrial fibrillation (CHA2DS2-VASc 4), aspirin 81 mg daily, and has a prosthetic right hip placed in 2019. He stopped apixaban three days ago on his own because he was told 'blood thinners cause bleeding.' He has no history of bleeding, bruising, or transfusion. Blood pressure is 152/88 mmHg. Preoperative INR is not applicable; creatinine clearance is 62 mL/min. The tumor is fixed to underlying cartilage on palpation, and there is no cervical lymphadenopathy. He asks whether he should stop aspirin too and whether he needs antibiotics for his hip.
1. How should his anticoagulant and antiplatelet therapy be managed around Mohs?
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For cutaneous surgery, continuing apixaban is generally safer than interrupting it because the thromboembolic risk from a CHA2DS2-VASc of 4 outweighs the modest bleeding risk of Mohs. He has already held it for three days, so confirm the last dose and coordinate with cardiology if there is uncertainty. Proceed with Mohs if his clinical status is stable, achieve meticulous hemostasis, and restart apixaban after hemostasis is secure, typically within 24 hours or per the prescribing team's plan. Routine heparin bridging is not indicated for atrial fibrillation and increases bleeding. Continue aspirin rather than stopping it; neither agent needs to be withdrawn for this procedure in most cases. Document the shared decision, and advise him not to self-discontinue anticoagulation in the future.
2. Does he need antibiotic prophylaxis for his prosthetic hip? Explain the evidence and guideline position.
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Routine antibiotic prophylaxis for a prosthetic joint is not recommended for dermatologic surgery. The risk of hematogenous prosthetic joint infection from a clean cutaneous procedure is very low, and there is no convincing evidence that prophylaxis reduces it. Current orthopedic and dental guidance restricts prophylaxis to selected high-risk situations, not routine skin surgery. He has a well-functioning hip placed in 2019 with no history of prosthetic joint infection, so prophylaxis would add cost, antimicrobial exposure, and resistance risk without clear benefit. If he had a recent joint replacement, prior prosthetic joint infection, or significant immunosuppression, discuss the rare exception with orthopedics, but do not give routine antibiotics. Treat any active skin infection separately and use sterile technique.
3. During Mohs, bleeding obscures the surgical field. What intraoperative and postoperative measures reduce recurrence and complications?
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Use a local anesthetic containing epinephrine; epinephrine is safe on the ear and improves hemostasis. Control bleeding with precise electrocoagulation, pressure, topical thrombin, and careful undermining rather than blind cautery that can distort the margin. Because the tumor is recurrent and fixed to cartilage, examine the cartilage and deep margin carefully; if cartilage invasion is suspected, discuss cartilage resection or multidisciplinary management rather than assuming Mohs clearance. Achieve layered closure or allow second-intention healing depending on the defect, and use a pressure dressing. Postoperatively, advise avoiding NSAIDs, monitor for hematoma, and arrange wound checks. Restart apixaban after hemostasis and confirm the plan with the patient's prescriber. Document that margin control, not speed, determines the extent of resection.