Introduction: Patients who fail all minimally invasive therapies for idiopathic (IDO) or neuropathic detrusor overactivity (NDO) undergo augmentation cystoplasty as a last resort. While the success rates are high, some patients continue to have resistant overactive incontinence symptoms. The management of these patients is undefined, and onabotulinum toxin A (BTX) is often employed to try and limit further interventional surgery. No literature exists that documents efficacy in this scenario. We have analysed the urodynamic and clinical response in this patient cohort
Methods: This is a retrospective review of all cystoplasty patients who underwent BTX injection at a tertiary centre between 2008-2019. Details including indications for cystoplasty, time from cystoplasty, video-urodynamic, BTX dose and clinical outcomes were analysed. BTX was injected into the remnant native bladder avoiding the bowel segment. A positive clinical response was considered improvement of overactive symptoms (incontinence) sufficient to merit repeat BTX injections. Outcomes at the end of the follow up period are documented. Poor compliance was defined as increase in pressure of more than 1cmH2O for every 40ml infused volume.
Results: 30 patients were identified (11 men and 19 women). Indications for augmentation, urodynamic findings and outcomes are shown in Table 1. The interval between cystoplasty and initial BTX was 98 months (range 3-271). Mean DO pressure was 43 (range (11 to 91). 100U BTX was used as an initial dose in 3 patients and the rest had either 200 or 300U. The overall response rate was 44% (8 / 18) for patient with IDO and 58% (7 /12) for NDO.
24 / 30 patients had persistent DO as a cause of their leakage. The response rate in this group was 46%. 13 / 30 patients had poor compliance with the majority (10) having associated DO. The response in this group was 8 / 13 (62%), all with DO/compliance loss, but it is not clear whether this was in response to DO or reduction in compliance pressures. Two out of the three (67%) patients with sensory symptoms responded well to BTX. In patients that failed BTX , 1 patient was managed with an SNM implant and 11/ 30 (37%) required further surgical intervention. The 15 patients who went on to have regular BTX experience a persistent benefit, with a mean 7.6 injections (range 2-16) over a period of 6.2 years (range 0.3 – 13.1 years). At their latest injection, three-quarters (11/15) received 300U BXT while the others received 200U.
Conclusions: Forty-four percent of IDO-cystoplasty patients responded well to BTX therapy, and 58% of NDO-cystoplasty patients. These patients continued to be maintained with BTX therapy. Patients who did not respond generally required further surgical intervention. It is not clear from this retrospective data whether compliance pressure or DO responds to the BTX therapy. Further urodynamic assessment is indicated to assess who is best to treat. Source of