Study design, materials and methods
Patients with AUS implanted during the period 1st January 2011 – 31th Dec 2018 were identified. Their records were retrospectively reviewed. Efficacy was assessed in terms of daily pad use, 1-hour pad test result, and the improvement in quality of life. Questionnaires used for the assessment of quality of life were the Incontinence Impact Questionnaire (IIQ-7), Urogenital Distress Inventory (UDI-6) and World Health Organization-Five Well Being Index (WHO-5). Complications rates were also reviewed.
Results
24 patients had AUS implanted, of which 1 was a revision surgery. AMS 800™ Urinary Control System was implanted in all cases. Mean age was 71 (range 50-85). The indications for surgery were post-prostatectomy incontinence (75%, n=18), post-TURP incontinence (17%, n=4) and neurogenic bladder (8%, n=2). 3 patients had pelvic radiotherapy prior to operation. Preoperative urodynamic studies found a mean abdominal leak point pressure of 52.8 cmH2O (range 14-104 cmH2O), and detrusor overactivity was found in 50% of the patients.
The social continence rate at 1 year, defined as 0-1 daily pad use, was 83%. Pre-operative mean daily pad use and mean 1-hour pad test was 5.3 and 58.4g, which decreased to 1 and 7.7g respectively at 1 year after the operation. Detrusor overactivity in preoperative urodynamic studies was not found to be a factor for failure.
Pre-operative mean scores of IIQ-7, UDI-6 and WHO-5 were 12.3, 10.5 and 60.8, which improved to 3.4, 5.1 and 66 respectively at 1 year after the operation.
At the time of the review, 75% of the AUS implanted were functional. 8% had mechanical failure but were not removed. 17% of the AUS were removed due to cuff erosion (n=3) or urethral erosion (n=1). There was 1 unfortunate case of infection, resulting in cuff erosion and explantation. Previous radiotherapy was not a risk factor for erosion or re-intervention.
Interpretation of results
The efficacy of AUS implantation in this series is comparable to the results reported in the literature. The social continence rate for international series averages at 79% according to a systematic review (1), while it was 83% in this series. Interestingly, 69% of patients reported being less bothered by storage symptoms after the operation according to UDI-6, while 23% were more bothered.
Improvement in the quality of life was seen according to IIQ-7 and UDI-6. This improvement was not detected with WHO-5. This questionnaire had been used to assess the subjective psychological well-being. Although WHO-5 was validated as an outcome measure in clinical trials and was successfully applied across a wide range of study fields (2), it may not be a good tool to reflect continence outcome. Another factor could be that male patients have a different perception of incontinence and have different coping strategies compared to female patients. There is a need to understand the impact of incontinence and its treatment on male patients’ self-image and emotional health. Psychosocial support and counselling may improve their sense of well-being.
There is unfortunately a higher incidence of erosion in this series. Cuff erosions occurred at a median time of 1 month after the operation, while pump erosion occurred at 23 months. There was an episode of epididymo-orchitis 2 months prior to pump erosion, and it is postulated that the inflammation of the tissue surrounding the pump has led to this complication. Proper cuff size selection, careful dissection, meticulous hemostasis and perioperative strategies to prevent infection remain the keys to prevent erosion and explantation.