The injection of botulinum toxin A into the bladder is a commonly practiced procedure. However, the specific manner in which it is carried out, such as dosage and policies concerning antibiotic prophylaxis and oral anticoagulation is not clearly defined in ICS standards, nor in the Dutch, Belgian and European guidelines. Therefore, a survey was conducted to investigate the implementation in Dutch and Belgian clinics.

The survey comprised 11 questions concerning the respondent (nationality, hospital type and role), the brand of botulinum toxin A utilized and its dosage, method of anesthesia, type and timing of antibiotic prophylaxis, policy regarding the continuation of oral anticoagulation, and post-injection procedures (whether catheterization is performed, outpatient admission, and type and timing of follow-up). The survey was conducted via SurveyMonkey® and distributed through LinkedIn, email to members of the Dutch Urological Association and was specifically brought to the attention of members of the Dutch Working Group on Functional Urology and Reconstructive Urology, the Pelvic Floor Working Group of the Dutch Gyneacological Association and the Belgian Working Group Functional Urology. Inclusion took place from March 19th to April 11th, 2024.

258 Participants completed the survey of which 257 could be included: 81.3% were urologists, 0% gynecologists, 12.8% were residents (not) in training, 3.9% were physician assistant or nurse practitioner, and 0.8% were classified as 'other'. Of these, respectively, 23.3%, 34.6%, 39.7%, and 1.9% worked in an academic, teaching, non-teaching hospital, or independent treatment center.

The majority primarily administered onabotulinumtoxinA (61.1% 100E, 20.2% 200E, 0.8% 300E, with 3.1% reporting both 100E and 200E), followed by abobotulinumtoxinA (11.7% 500E, 0.8% 1000E) and incobotulinumtoxinA (2 urologists).

Regarding the use of anesthesia (and type), antibiotic prophylaxis (and type), management of oral anticoagulation, and post-injection policies/monitoring, substantial variation in responses was observed (see Table ).

No antibiotic prophylaxis was administered by 35.6% of the respondents, while 36.4% were based their antibiotic choice on recent culture results, and standard antibiotic prophylaxis was utilized by 28.0% of respondents.

In the study, anticoagulation management varied; approximately 4.3% stopped all anticoagulation. The most common approach (67.1%) was to continue acetylsalicylic acid and cease stronger anticoagulants. In 14.9% of respondents, both Clopidogrel/Ticagrelor and stronger anticoagulants were stopped. Continuing direct oral anticoagulants while stopping stronger ones occurred in 3.5% of cases. Lastly, 10.2% continued Vitamin K antagonists.

Regarding anesthetic methods, lidocaine bladder installation was the predominant choice in the majority of respondents (72.3%). A smaller proportion of cases (13.3%) were performed in the operating room under general anesthesia or spinal anesthesia, while sedation was used in 9.4% of instances. Only a minority (2.3%) of cases proceeded without anesthesia or in the operation room with lidocaine bladder installation (0.8%). Additionally, in 2.0% of cases, more than one anesthetic method was employed.

Moreover, the study identified notable distinctions between respondents from the Netherlands and Belgium. 
It's important to mention that there were fewer Belgian participants in the study (31 respondents, 12.1%), so we need to be careful when making strong conclusions about any big differences. Specifically, Belgian respondents did not employ abobotulinumtoxinA and administered lidocaine bladder installation less frequently than the Dutch respondents. Furthermore, patients in Belgium were more frequently admitted for standard day care treatment.
There was also a notable preference for physical appointments among Belgian participants, resulting in a comparatively lower frequency of telephone follow-ups.

The survey gives insights into how botulinum toxin A is used. Most respondents were urologists and urology residents (94.6%), mainly dealing with these procedures. They came from various types of hospitals, with many from academic and teaching hospitals.

The survey showed that onabotulinumtoxinA, particularly in the 100E dosage, was the most commonly used, followed by abobotulinumtoxinA and incobotulinumtoxinA. It is worth noting that the selection of botulinum toxin A type might be influenced by the fact that abobotulinumtoxin only received labeling for bladder use in Belgium from July 2023. Furthermore, respondents frequently mentioned that the dosage of botulinum toxin A, whether 100 or 200 IU, depended on the presence or absence of adult neurogenic lower urinary tract dysfunction. Obvious variations were seen in how anesthesia was administered, how antibiotics were used, and how patients were monitored after injection. In Belgium, the higher frequency of standard day care treatment admissions may be attributed to reimbursement policies that favor day care treatment. These findings suggest there's no standard way of care nationally and internationally.

There was also variability in how anticoagulation therapy was managed after the injection. While many stopped stronger anticoagulants but continued with acetylsalicylic acid, others stopped both stronger anticoagulants and Clopidogrel/Ticagrelor. Some continued with direct oral anticoagulants but stopped the stronger ones.

Lidocaine bladder installation was the most popular choice for anesthesia, but there were different methods of anesthesia used, like general anesthesia, spinal anesthesia, or sedation. This highlights the variability in healthcare organization and practices within the Netherlands and Belgium. 

There appears to be major variation in the practice of botulinum toxin A in the overactive bladder therapy. In this study, there appears to be substantial national and international variation in both the Netherlands and Belgium, noting that, because of the lower number of Belgian respondents included, it's important to be cautious when interpreting these differences internationally. Overall, the findings suggest a need for more research to create guidelines for botulinum toxin A administration. It is also important to consider how payment arrangements might affect these practices, although other factors like clinical guidelines and individual preferences may play a role.

Considering this survey's exclusion of other potential factors such as injection frequency, targeting of the trigone, and the extent of sterile procedures, it prompts the question: is there a definitive treatment for botulinum toxin A?
In addition to the potential effects of practice variation on treatment outcomes, its impact on costs and sustainability should also be taken into account.

Continence 12S (2024) 101520
DOI: 10.1016/j.cont.2024.101520