Study design, materials and methods
The study was a retrospective analysis of CYP in a Spinal Cord Injury Centre (SCIC) who have received IDI of BTXA as part of bladder management for NDO. All patients had urodynamically proven NDO. Age at injury, cause of injury, impairment, bladder management, age at first injection, number of repeat injections, dose and formulation of BTXA, and current bladder management status of patients was recorded. A Kaplan Meier survival curve was created to determine the feasibility of long term treatment with IDI of BTXA.
Interpretation of results
The initial results (after 1 or 2 injections) were satisfactory for the majority of the patients based on urodynamics results and patient reporting. Three patients were not re-treated after the first injections either due to inefficacy or patient choice. A further 2 discontinued treatment after 2-5 injections. Patients who have received more than 5 repeat injections reported decreasing efficacy of treatment with shorter duration of effect and increased incontinence. This was more apparent in the patients who manage their bladder with intermittent catheterisation (IC) compared to a supra-pubic catheter (SPC). In patients who have received more than 5 repeat injections, the dose has gradually increased to the maximum permitted dose, and the frequency of injection has increased from annually to every 6 months. 2 patients who have had more than 5 repeated injections have been offered bladder reconstruction surgery due to inefficacy of IDI of BTXA; a further 3 patients are continuing with IDI of BTXA but report reduced duration of effect. The 2 patients who have received more than 10 injections both reported that the treatment has reduced duration of effect with increased incontinence and smaller capacity. One (performing IC) has been offered bladder augmentation (ileocystoplasty) and one (using SPC) is continuing but at the highest dose, and more frequent intervals. The Kaplan Meier survival graph for patients continuing with treatment is shown in Figure 1.