Chronic urinary retention in young women is uncommon and Fowler’s Syndrome typically presents as painless urinary retention, characterised by a primary disorder of urethral sphincter relaxation typically associated with an elevated urethral pressure profile and abnormal findings in urethral sphincter EMG.   Sacral neuromodulation is effective in treating urinary retention in nearly  70% of women with Fowler’s syndrome, however this treatment may not be feasible for all patients because of concomitant medical co-morbidities, patient choice, or in health care settings with limited financial resources.   A recent clinical trial demonstrated that EMG guided transperineal injections of botulinum toxin into the external urethral  sphincter was an effective and safe outpatient-based alternative for managing urinary retention [1].   

The aim of this study was to prospectively evaluate the delivery of botulinum toxin treatment for managing urinary retention in women with Fowler’s syndrome in a real-world setting during the COVID pandemic and to evaluate efficacy, safety and side-effect profiles.

A service offering botulinum toxin injections into the urethral sphincter for managing urinary retention in women with Fowler’s syndrome was set up in 2011.  Due to the COVID pandemic, several services were closed in 2020 however the sphincter botulinum toxin clinic was prioritised and, exceptionally, kept open so that  women could continue to receive this treatment to avoid going into urinary retention and falling back on catheterisation.  Women meeting the criteria for Fowler’s Syndrome, (abnormal concentric needle EMG of the striated urethral sphincter and/or abnormally elevated urethral pressure profile)  were offered this treatment in case they were not suitable for sacral neuromodulation.  OnabotulinumtoxinA was injected into the external urethral sphincter as an outpatient procedure. 1 mL 2% lidocaine was injected on either side of the external urethral meatus initially, then 100 U onabotulinumtoxinA  dissolved in 2 mL saline was injected into the striated urethral sphincter transperineally.  

Women were followed up after 4 weeks through a telephone consultation, and they contacted the department for repeat injections when the effects began to diminish, after an embargo period of 12 weeks.  

Efficacy and side effects were assessed at baseline and 4 weeks after the injection using a standard battery of questions and questionnaires (International Prostate Symptom Score (IPSS) and Patient Perception of Intensity of Urgency score).

Women who were not required to shield and were deemed to be at low risk for developing COVID-related complications were seen in designated parts of the hospital where adequate precautions could be taken signed off by the Trust Infection Control Team ( “green” COVID pathway).  During this period, 17 women diagnosed with Fowler’s Syndrome (mean age 35.0±12.4 years) received 100U botulinum toxin injected EMG-guided into the external urethral sphincter as an out-patient procedure between 1st January 2020 and 31st December 2021.  14 (87.5%) women were dependent on intermittent self-catheterisation (ISC) and 2 (12.5%) had voiding difficulties but were not ISC dependent.   48 injections were administered and 12 women (71%) reported improvements in urinary symptoms across 37/48 injections (77% of injections).  9 women (53%) received >1 injection [median 4 injections/patient, median interval 3.5 months].

The improvements observed by women who responded to the injections (n=37 injections in 12 women) are summarised in Figure 1.
Amongst women requiring to recommence intermittent self-catheterisation, the mean time to requiring ISC was 2.95±0.41 months [median 3 months].  

Side effects reported were relatively mild:
•	transient stress incontinence (n=3), resolving within 2 weeks 
•	short-lasting pain and bleeding (n=3), resolving within 24 hours 
•	Increased pre-existing urinary urgency incontinence (n=2) 

Compared between baseline and 4 weeks post-injection, there was an improvement in mean International Prostate Symptom Score (IPSS) score from 20.5 to 12.83 and improvement in Patient Perception of Intensity of Urgency score from 0.87 to 2.03 (p<0.05) (n=6).

The results of this audit suggest that it has been feasible to continue offering sphincter botulinum toxin injections for the management of chronic urinary  retention due to Fowler’s Syndrome during the pandemic.   None of the women had developed COVID when evaluated at 4 weeks after injection.  Treatment effects could be accurately assessed over the phone at four weeks, however questionnaire data was not easy to collect.  
71% of women reported benefit to treatment, with a duration of effect that was expected for striated muscles (median 3 months).   The results suggest that the most common  improvement  was a reduction in ISC requirement, and 32% of respondents became free of catheterisation.  Other benefits in those who continued to catheterise included a greater ease and reduced pain with catheterisation.  Perception of bladder fullness was also found to improve as well.  Side effects associated with botulinum toxin were uncommon, and stress urinary incontinence was reported by only a small number of patients and occurred transiently.  The outcomes in this real-world support the findings from an earlier clinical trial in women with Fowler’s Syndrome [1] and in adults with dysfunctional voiding [2].

The results of this  study suggests that transperineal EMG-guided minimally-invasive urethral sphincter botulinum toxin injections administered during the COVID  pandemic significantly improved urinary symptoms amongst women with urinary retention due to Fowler’s syndrome and was well tolerated.

Panicker JN, Seth JH, Khan S, Gonzales G, Haslam C, Kessler TM, Fowler CJ. Open-label study evaluating outpatient urethral sphincter injections of onabotulinumtoxinA to treat women with urinary retention due to a primary disorder of sphincter relaxation (Fowler's syndrome). BJU Int. 2016 May;117(5):809-13. doi: 10.1111/bju.13342.
Liao YM, Kuo HC. Causes of failed urethral botulinum toxin A treatment for emptying failure. Urology. 2007 Oct;70(4):763-6. doi: 10.1016/j.urology.2007.06.1083. Epub 2007 Aug 20.

Continence 2S2 (2022) 100261
DOI: 10.1016/j.cont.2022.100261