Where the clot risk actually is in ENT surgery

Design

Retrospective national database study (Atropos, 66 million patients), univariable risk analysis

Population

277,187 adults undergoing ENT surgery in the United States, 2015 to 2025

Primary outcome

Venous thromboembolism within 90 days of surgery

Effect

Overall 0.63%; free tissue transfer 6.1%, lateral skull base 4.4%, cricopharyngeal myotomy and anterior skull base 3.1%; prior VTE OR 12.3 (95% CI 11.2 to 13.4)

A national aggregated database of 66 million patients yielded 277,187 adults who had ENT surgery between 2015 and 2025, followed for venous thromboembolism at 90 days. Overall the rate was 0.63 per cent, which is low enough to explain why chemoprophylaxis is inconsistent across the specialty.

The average conceals the decision. By subspecialty, head and neck ran at 1.3 per cent and sleep surgery at 0.3 per cent. By procedure, free tissue transfer was 6.1 per cent, lateral skull base 4.4 per cent, and cricopharyngeal myotomy and anterior skull base surgery 3.1 per cent each. That is a tenfold spread within one specialty's operating lists.

The strongest single risk factor was a previous venous thromboembolism, at an odds ratio of 12.3 — larger than any procedural category. So the two questions that should decide prophylaxis are which operation and whether they have had a clot before, asked together rather than by protocol.

• Ask about previous venous thromboembolism in every ENT pre-assessment; it outweighed every procedural factor here.
• Set your chemoprophylaxis threshold by procedure, not by specialty.
• Free flap, skull base and cricopharyngeal myotomy patients belong in the high-risk pathway.
• Balance against bleeding risk in the same conversation — this study measured only thrombosis.
• Audit which of your own ENT procedures are being given prophylaxis; the spread here suggests habit rather than risk drives it.

Why it matters

It replaces a specialty-wide assumption that ENT is low risk with a list of the operations where it is not.

Don't overread it

Database coding with univariable risk analysis only; this describes which patients clot, not whether prophylaxis prevents it.

The statistics, in plain English

Risk factors were assessed by univariable analysis only, so the odds ratio of 12.3 for prior venous thromboembolism is unadjusted — some of it reflects the comorbidity that caused the first clot rather than the surgery. Procedural rates come from administrative coding across a decade, which captures events that reached medical attention and misses those that did not. The low overall rate means small absolute differences look large in relative terms.

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