Bleeding risk in female patients undergoing intravesical injection of onabotulinumtoxinA for overactive bladder: a Danish retrospective cohort study

INTRODUCTION AND HYPOTHESIS: We aimed to examine the risk of bleeding in female patients undergoing intravesical onabotulinumtoxinA (BTX-A) treatments and provide clinical recommendations for the perioperative management of patients on antithrombotic therapy prior to BTX-A treatments. METHODS: This was a retrospective cohort of Danish female patients, who had their first BTX-A treatment because of an overactive bladder at the Department of Gynecology and Obstetrics, Herlev and Gentofte University Hospital, between January 2015 and December 2020. Data extraction was from an electronic medical journal system. BTX-A, Botox® Allergan was injected in the detrusor at 10–20 sites. Significant bleeding during or after a BTX-A treatment was defined as persistent macroscopic hematuria. Bleeding reporting was based on information obtained from journal notes. RESULTS: We included 400 female patients, who had a total of 1,059 BTX-A treatments. Median age at first BTX-A treatment was 70 years (IQR 21), and median number of BTX-A treatments was 2 (range 1–11). In total, 27.8% (n=111) received antithrombotic therapy. Within this group, 30.6% and 69.4% were on anticoagulant and antiplatelet therapy. No cases of hematuria were reported in our cohort. We found that no patients stopped their antithrombotic therapy, were bridged, or monitored by International Normalized Ration (INR) levels. CONCLUSIONS: We suggest that BTX-A treatments might be classified as low-risk procedures. Discontinuation of antithrombotic therapy is not required in the perioperative management of this patient group.