In patients with suprapubic tubes (SPTs), complaints of urinary leakage per urethra or around the tube are common, and are often refractory to medical therapy. Intradetrusor onabotulinumtoxinA (BTX-A) injection is considered a “next step” for these patients. However, potential benefit must be balanced with risk factors inherent to patients with indwelling catheters including bacterial colonization and chronic inflammatory changes to bladder mucosa. We assessed the use of intradetrusor BTX-A in the setting of existing or concomitant SPT as a safe way to decrease urinary leakage.

Patients undergoing BTX-A injection with an in situ or concomitantly placed SPT at a single institution from 2007 to 2017 were retrospectively reviewed utilizing CPT codes. Clinical characteristics of patients were abstracted including  pre-procedure urinalysis and urine culture and peri-procedural use of antibiotics. Outcomes considered included complications such as 30 day post-procedure urinary tract infection (UTI), bleeding, or hospitalization, as well as degree of perceived improvement. Patient characteristics were assessed by chi-square or t-test analyses and outcomes were assessed by univariable and multivariable logistic regression models.

A total of fifty patients underwent BTX-A injection in the setting of SPT. Thirty (60%) of these patients had an in situ SPT at time of first BTX-A injection compared to 20 (40%) patients who had a SPT placed at the time of their first botox injection. The majority of the cohort (86%) was female.  Mean age was 59 years, ranging from 16-82 years, and mean BMI was 30.1 kg/m2. The most common overlapping indications for BTX-A injection were neurogenic bladder (86%), urinary incontinence (52%), and urgency/frequency (30%). 

Patients within our cohort had an average of four BTX-A injections total (range 1-12) and 88% reported subjective improvement as well as decreased leakage after their first BTX injection (p=0.03). 

Overall complication rate for intradetrusor BTX-A injection in the setting of in situ or concomitantly placed SPTs was 12% with hematuria and UTI being the most common adverse effects. Although there were more instances of post procedure bleeding in the concomitantly placed SPT group (10% vs 3%), with one occasion requiring admission for clot evacuation, there was no statistically significant difference in complication rate between patients with in situ vs. concomitantly placed SPT at time of first botox (6% vs 20%, p=0.16). 

Pre-procedural urine cultures were positive at time of injection among 56% of patients. Nearly all patients received documented peri-procedural antibiotics (96%) and 44% received a post-procedure antibiotic course. Positive preoperative urine culture correlated to increased likelihood of prescribed post-procedure antibiotics (OR: 3.56, p=0.04). Post procedure antibiotic course did not cause a statistically significant difference in post procedure UTI rate as 22 patients received an antibiotic course after first BTX-A and one (4.5%) had a post procedure UTI compared to the 1 of 27 patients (3.7%) who did not receive post procedure antibiotics and had an UTI (OR: 0.82, p = 0.88).

Additionally, 28 patients were managed with a catheter associated urinary tract infection prophylaxis irrigation regimen during their SPT management. The majority of patients used normal saline as part of their routine (43%), followed by 3% saline (29%), acetic acid (14%) and gentamicin solution (7%). Nineteen of the patients (38%) were on a UTI prophylaxis irrigation regimen prior to first BTX-A (n=12 for in situ SPT and n = 7 for concomitant SPT patients), none of whom (0%) had a post procedure UTI.

Results showed that the majority of patients with in situ or concomitantly placed SPTs experienced decreased urinary leakage post procedure. Complication rates in patients in both sub groups (in situ vs concomitant SPTs) were low and comparable to complication rates in the literature of BTX-A injection in the absence of a SPT. However, decreased UTI rate is likely multifactorial as patients received a combination of preventive measures including prophylaxis irrigation regimen as well as peri and post procedural antibiotics.

Intradetrusor BTX-A injection appears to be safe and efficacious in patients with in situ and concomitantly placed SPTs, with the most common complication being UTI or bleeding. The risk factors of chronic colonization and mucosal changes associated with an in situ tube and the extra bladder puncture executed with concomitant SPT placement did not contribute to a statistically significant difference in UTI or bleeding rates between sub groups. Prophylaxis regimens initiated prior to first BTX-A injection may help minimize complication rates of UTI and post procedure antibiotic course does not appear to decrease UTI rate. BTX-A injections should continue to be considered for reducing urinary leakage in this challenging to manage population.