Short-term IV iron was not linked to fewer transfusions after head and neck free flaps

Design

Retrospective single-centre cohort

Population

324 adults having head and neck free flap reconstruction, 32 given preoperative IV iron

Primary outcome

Postoperative red cell transfusion

Effect

IV iron aOR 1.26 (95% CI 0.51–3.08); haemoglobin aOR 0.96 per g/L (0.94–0.98)

A retrospective cohort at a Canadian tertiary head and neck centre included 324 adults having free flap reconstruction for cancer between 2022 and 2025. From mid-2022, patients with haemoglobin below 130 g/L had transferrin saturation tested, and those below 20% could receive intravenous iron before surgery; 32 did.

Postoperative red cell transfusion was needed in 18.2%. Preoperative IV iron was not associated with transfusion risk (adjusted OR 1.26, 95% CI 0.51–3.08) or with the number of units given, even when restricted to those who received iron at least 7 days before surgery. Higher preoperative haemoglobin was associated with lower risk (OR 0.96 per g/L), and advanced tumour stage with higher risk (OR 2.55).

The iron group was small and, by design, iron-deficient, so a real benefit could be hidden. But the timing is the likely problem: head and neck cancer surgery is booked quickly, leaving little time for iron to raise haemoglobin. Detecting anaemia at the first visit, rather than at pre-assessment, gives any treatment a chance to work.

• Check haemoglobin and iron studies at the first head and neck cancer clinic visit, not only at pre-assessment.
• Start iron as early as the pathway allows; a week or two may be too short to change haemoglobin.
• Expect higher transfusion need in advanced-stage disease and plan cross-match accordingly.
• Look for other causes of anaemia, such as chronic disease or nutritional deficits, alongside iron.

Why it matters

Iron infusion is increasingly added before surgery, but its timing in fast cancer pathways may make it ineffective.

Don't overread it

Small, non-randomised iron group — this does not show IV iron is ineffective when given earlier.

The statistics, in plain English

An odds ratio of 1.26 with an interval from 0.51 to 3.08 is compatible with iron helping, doing nothing or doing harm; with only 32 treated patients, the study could not tell. Haemoglobin itself was the clearer predictor: each 1 g/L higher, about 4% lower odds of transfusion.

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