#96 Roles Of Urodynamics In the Assessment of Post Radical Prostatectomy Incontinence: Do Findings Change Patient Management? Cheng J1, Patel A2, Tse V1, Chan L1 1. Concord Repatriation General Hospital, Sydney, Australia, 2. City Hospitals Sunderland NHS Foundation Trust, UK Introduction Urinary incontinence after radical prostatectomy is aetiologically diverse, and not solely confined to post-surgical stress urinary incontinence (SUI). Previous studies have shown overall incidence of detrusor overactivity (DO) in this group ranging between 25-63% (1). However, depending on local practice patterns, urodynamic studies may or may not be performed in men prior to surgery for SUI. Historically, urodynamics have successfully directed management of post prostatectomy patients who had surgery performed for benign or malignant conditions (2). With increasing treatment options for overactive bladder and new surgical procedures for male SUI, we aimed to evaluate the impact of urodynamic study findings on subsequent patient management in a contemporary cohort of prostate cancer patients with post radical prostatectomy incontinence. Materials and Methods Prostate cancer patients with urinary incontinence post open radical prostatectomy, who had failed conservative management/Kegel exercises and being considered for surgical treatment underwent multichannel urodynamic studies according to ICS standards between 2011 and 2015. All urodynamic studies were performed at least 9 months post radical prostatectomy. Patients with adjuvant or salvage radiotherapy, as well as those who have undergone previous surgical treatments for SUI were also included. Urodynamic findings were reviewed and subsequent patient management outcomes obtained from medical records. Patients who had laparoscopic or robotic radical prostatectomies were excluded, as were patients treated with radiotherapy alone. Results 115 patients (age 51-87, median age 69) were included, with median pad weight of 250g (50-1000g). 17 patients (15%) had diabetes and 10 patients (9%) had other relevant comorbidities (Table 1). Table 1 Relevant comorbidities Prior to urodynamics, 31 patients (27%) had adjuvant or salvage external beam radiotherapy, 16 (14%) had prior SUI surgery, and 4 patients (3%) had both. Overall, DO was demonstrated in 51 patients (44%) and 48 patients (42%) had reduced compliance on filling. In total, 66 patients (57%) had filling phase abnormalities detected on urodynamics. These abnormalities were more common amongst patients who had prior SUI surgery (75%) and those with previous external beam radiotherapy (74%). (Figure 1) Figure 1 Patient characteristics and filling phase abnormalities In patients with DO, 57% (29/51) were treated solely with anticholinergics, mirabegron or intravesical onabotulinumtoxinA, and did not proceed to surgical management for SUI. 25% (13/51) of patients with DO were managed with surgical treatment for SUI alone and 18% (9/51) received treatment for DO prior to undergoing surgery for SUI. Of those who underwent treatment for DO, 34% (13/38) were drug refractory and received onabotulinumtoxinA. The type(s) of incontinence demonstrated on urodynamic study, as well as subsequent patient management are outlined in Figure 2. Figure 2 Treatment of patients with urodynamic detrusor overactivity In patients without DO, only 6% (4/64) of patients required treatment with anticholinergics, mirabegron or onabotulinumtoxinA, either in isolation or combined with surgical treatment for SUI. These patients were treated on the basis of decreased compliance +/- decreased functional capacity. The majority (81%, 52/64) of patients without DO proceeded to surgical management for SUI. Overall, urodynamic findings had a direct impact upon patient management in 36.5% (42/115) patients. (Table 2) Table 2 Urodynamic findings and their influence on patient management Discussion We found DO to be a common finding (44%) in our group of men presenting with moderate urinary incontinence post radical prostatectomy, who were initially deemed suitable candidates for consideration of SUI surgery. Regardless of whether there is a previous history of failed SUI surgery, a third of our patients were managed differently as a result of their urodynamic findings, and did not proceed to SUI surgery as their sole form of treatment. More than half of our patients with urodynamic detrusor overactivity were managed by treatment of their DO alone, and did not proceed to surgical treatment for SUI. Had urodynamics not been performed, these patients may have gone ahead with either a sling or an artificial urinary sphincter implantation. In contrast, many patients without DO proceeded to surgical treatment for SUI alone. Whilst the finding of preoperative urodynamic bladder dysfunction may not influence the outcome of SUI surgery (3), knowledge of the presence of DO assisted our patient counselling prior to SUI surgery. In addition, our urodynamic findings enabled us to select the most appropriate surgical treatment options for individual patients who have previously undergone SUI surgery. Conclusion Bladder dysfunction is an important cause of post prostatectomy incontinence in addition to sphincter insufficiency, and a significant proportion of such patients can be successfully treated without requiring surgical treatment. Urodynamic study plays an important role in patient evaluation, and helps to optimise the opportunity for successful treatment outcome by guiding individual patient management.   References 1. Thiruchelvam N et al. A review of detrusor overactivity and the overactive bladder after radical prostate cancer treatment BJUI 2015 Dec;116(6):853-61 2. Leach GE and Yun SK Post-prostatectomy incontinence: Part II. The results of treatment based on urodynamic evaluation Neurourol Urodyn 1992; 11:99-105 3. Holm HV et al. Severe postprostatectomy incontinence: Is there an association between preoperative urodynamic findings and outcome of incontinence surgery Scand J Urol 2015 Jun; 49(3):250-9 Urodynamic finding Outcome Patient number DO Treatment with anticholinergics, mirabegron or onabotulinumtoxinA, either in isolation or combined with surgical treatment for SUI 40 Bladder outlet obstruction Existing sling divided prior to insertion of AUS 1 Existing sling well positioned on ultrasound Patient underwent AUS rather than revision of existing sling Relevant Comorbidities Patient number Diabetes 17 Stroke (CVA/TIA) 4 Parkinson’s 2 Psychotropic medication use Previous spinal surgery 1 Hydrocephalus Disclosure: None of the authors have financial ties with any business organisations with respect to the subjects mentioned in this study.