Should HRT be stopped before major surgery?
QShould HRT be stopped before major surgery such as hip replacement? If so when, and when can it be restarted?
AIn trials of thromboprophylaxis in orthopaedic surgery, rates of total and proximal VTE after hip replacement are 16.1 per cent and 5.9 per cent respectively. It is highly desirable to avoid increasing the risk any further.
A link between HRT and risk of venous thrombosis has been shown by a series of studies demonstrating a two- to four-fold increased risk. It is known that HRT results in increased resistance to activated Protein C and that these changes disappear soon after stopping HRT. There is no published study looking at HRT as a risk factor for post-operative venous thrombosis the association is assumed from data on spontaneous thrombosis.
While views on the role of HRT are changing, many women in the UK are prescribed HRT in the short-term to prevent peri-menopausal symptoms. Women may have HRT prescribed for longer to prevent osteoporosis.
There cannot be many clinical situations where interrupting HRT for a short time would result in any significant morbidity. So for the majority of women on HRT the recommendation would be to stop HRT before any major surgery to decrease the assumed increased risk of venous thrombosis.
In France it is recommended that HRT be stopped four weeks before surgery. There are no British guidelines. After orthopaedic surgery it is now recognised that the increased risk of venous thrombosis persists for four to six weeks. HRT should not be reintroduced until at least six weeks post-op, if the woman is mobile.
Dr Caroline Shiach is
consultant haematologist at Manchester Royal Infirmary