Position of Enoxaparin and DOACs in Extended Prevention of VTE After Surgeries for Gynecological Malignancies

Introduction

Studies confirm that extended thromboprophylaxis reduces mortality and morbidity related to venous thromboembolism (VTE) post-surgery in oncological patients. However, regimens and recommendations vary. For surgeries of gynecological malignancies, current international guidelines recommend 28-day administration of enoxaparin.

As for DOACs, even though these drugs are commonly used in the treatment of VTE associated with malignancy, there is insufficient data for their use in postoperative thromboprophylaxis in oncological patients. To date, only one study has been published focusing on the use of apixaban in thromboprophylaxis after gynecological malignancy surgery, which did not provide sufficiently reliable safety evidence for changing the existing guidelines. DOACs, however, have undeniable advantages over low molecular weight heparins (LMWH), such as a more convenient method of administration and no need for laboratory monitoring of effect, which is why experts are increasingly viewing them as a potential alternative for extended postoperative VTE prophylaxis. For this reason, the cited Australian and New Zealand study also focused on their routine use in postoperative thromboprophylaxis.

Survey Study

For the study purposes, a total of 67 gynecologic oncologists were approached with online questionnaires concerning their used postoperative prophylactic regimes and the potential use of DOACs in these situations. The aim was to determine the current practice of thromboprophylaxis primarily after gynecologic laparotomies. A total of 48 out of 67 respondents (71.6%) completed the questionnaire.

Findings

The utilized regimens varied not only according to the type of surgery performed, but there was no uniformity even within the same category. The only consensus was regarding the use of DOACs — none of the surveyed specialists routinely used them in thromboprophylaxis after gynecologic oncological procedures.

The most consensus was seen in the regime after laparotomic surgery for gynecological malignancies. 77% of gynecologic oncologists reported using a 28-day enoxaparin regimen, as recommended by international guidelines. Others used either a 21-day regimen (8.3%), heparin administration during hospitalization followed by 28 days of enoxaparin (6.2%), enoxaparin administration only during hospitalization (2.1%), compression stockings (2.1%), and the remaining 4.2% assessed the need for prophylaxis based on the patient's VTE risk. 66% of gynecologic oncologists stated that they would offer DOACs as an alternative to patients post-laparotomy if there were no contraindications, while 10.6% would not use any thromboprophylactic regimen if enoxaparin were unavailable.

Regarding thromboprophylaxis post-laparoscopic surgery for gynecological malignancies, 34% of gynecologic oncologists prescribe a 28-day enoxaparin regimen, 19% do not indicate any standard procedure and focus on recommendations based on the patient's VTE risk stratification, 17% use enoxaparin only during hospitalization, 6.4% administer enoxaparin for 7–14 days, and 2.1% prescribe compression stockings and sequential compression devices.

For surgeries of vulvar malignancies, 37.5% of gynecologic oncologists use the 28-day enoxaparin regimen, 27% use enoxaparin only during hospitalization, 19% do not indicate any standard procedure and focus on recommendations based on the patient's VTE risk stratification, and 4.2% prescribe the use of compression stockings and sequential compression devices.

56% of the surveyed specialists had already used direct oral anticoagulants in VTE prophylaxis, with apixaban being the most used, followed by rivaroxaban. The reasons most frequently cited for not routinely using DOACs in prophylaxis were a lack of data (68%) and cost (40%; in Australia and New Zealand, DOACs are not covered for thromboprophylaxis use).

Conclusion

The 28-day enoxaparin regimen remains the clinical standard in thromboprophylaxis post-laparotomic surgery for gynecological malignancies. The main barrier to the routine use of DOACs in these cases is the lack of high-quality data from studies.

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Sources: Boo M., Simcock B., Sykes P., Brand A. Direct oral anticoagulants (DOACs) use for prolonged venous thromboembolism prophylaxis following surgery for gynaecological malignancies in Australia and New Zealand − a clinician survey. Aust N Z J Obstet Gynaecol 2023 Jul 11, doi: 10.1111/ajo.13737 [Epub ahead of print].