Estrogens in the Perioperative Period: Remarks from the Ansesthesiology Literature

2001 review article is unfortunately one of the more recent publications on the subject.  (1)

     The perioperative use of estrogen cross-sex hormone therapy (csHT) is a topic of controversy in both transgender women as well as in cisgender women taking menopausal HRT or combined oral contraceptives (OCP).  Little data exists in any context with respect to perioperative venous thromboembolic risks (VTE) in those patients taking estrogen of any type and for any reason.  Most guidelines are based on consensus opinion and of varying vintage.

     This review article aimed to review perioperative estrogen therapy from the reference frame of the anasthesiologist.  While the article reviews a number of conditions of interest, the section focusing on perioperative VTE will be discussed here.

     It is first mentioned that studies of VTE in estrogen therapy of any kind suggest relative risk of 2-3 for users vs. non-users.  While these studies are still equivocal and suggest that the risk is greatest in the first year of therapy, the 2-3x increase in risk likely translates into a real world increase of 1-2 cases per 10,000 women per year.  Furthermore, there may be a subset of users at baseline higher risk due to occult prothrombotic states, which have a 6.2% baseline prevalence in the general population, but a 60.2% prevalence in those with a personal or family history of VTE.

     The authors conclude that no evidence-based recommendations can be made with respect to withholding perioperative estrogen therapy, nor with respect to postoperative VTE prophylaxis with heparin.  Recommendations from various British bodies and organizations are presented showing a range of conflicting and equivocal recommendations.  Providers are advised to rely on clinical judgment.   

Comments:
 
     This 11 year old article unfortunately represents one of the more recent publications on the issue of perioperative VTE and estrogen therapy; randomized controlled trials are sorely lacking.  In the discussion the author mentions that withholding perioperative OCP may result in an unwanted pregnancy with attendant risks and morbidity; it is recommended that physicians consider these risks when analyzing the pros and cons on an individual basis.  The same thought process should be applied for transwomen, who may experience significant emotional symptoms from hormone withdrawal in what is for many an already extremely stressful event.  In the case of transwomen, it is likely safe to continue csHT in the perioperative period if they have no personal or family risk factors, have been on csHT for > 1 year, wear sequential compression devices postoperatively, and have received informed consent about the minimal absolute risk increase.  Providers should also keep in mind the background rate of VTE in major pelvic surgery without the use of estrogens.


References:

1) Brighouse, D.  Hormone Replacement Therapy and Anaesthesia.  British Journal of Anaesthesia 86(5): 709-16.