Hypothesis / aims of study
First developed in 2008, the Adjustable Transobturator Male System (ATOMS) has recently gained popularity in the post-prostatectomy incontinence (PPI) scene, touting advantages such as surgical simplicity and post-operative adjustability, among others (1). The present study aims to explore this device as a potential treatment option for PPI. With the help of preoperative urodynamic testing, this study also includes a subgroup analysis of patients suffering from concomitant overactive bladder (OAB) as well as those having received prior radiotherapy before device installation.
Primary outcome was dryness rate, 24-hour pad-count change compared to baseline and results from the patient global impression of improvement (PGI-I) questionnaire. Secondary outcome was the frequency of postoperative adverse events, as well as the effects of concomitant OAB and prior radiotherapy on the device effectiveness and safety.
Study design, materials and methods
This was a single-center retrospective study. All implantations of the third generation Adjustable Trans Obturator Male System for post-prostatectomy incontinence were performed by one surgeon between June 2015 and March 2021. Prior to ATOMS implantation, all patients underwent a thorough work up including questionnaires, bladder diary, pad weight test, pad count, urodynamic study and cystoscopy.
Pre-operative urinary incontinence severity was defined as <2 pads per day (PPD), 2-4 PPD, and >4 PPD with regards to 24-h pad-count and/or <200g, 200-400g, and >400g regarding the 24-h pad-test (24h-PT) to classify mild, moderate, and severe incontinence, respectively. Dryness was defined as requiring 0 or 1 PPD postoperatively. Patients considered “improved” or “very much improved” were defined as having a reduction in the number of pads per day by ≥ 50% or ≥ 75%, respectively. Finally, significant patient satisfaction was defined by “much better”, and “Very much better” PGI-I results.
The obtained data was compiled in Microsoft® Excel® format (v.16.59, 2022) and was converted to SPSS v.26 (IBM Corp. Armonk, N.Y., USA) for analysis.
Results
Medical records of 91 patients were analysed. The median patient age for this group was 71 years with a mean follow-up of 29.9 months (SE 1.8; range 12 - 67). Pre-operative pad per day median was 4 (IQR 6-3; range 1-10), and pre-operative 24-hour pad test was 358 g (IQR 607-256; range 34-1592). This classified most patients as being either moderately (n=24; 36.9%) or severely (n=40; 61.5%) incontinent pre-operatively.
Post-operatively, median PPD at final follow-up was 1.0 (IQR 2-0; range 0-5; p < 0.001), with an overall improvement being noted in 56 (86.2%) patients. Within these 56 patients having improved, 43 (76.7%) of them were “very much improved” and of them 42 (75.0%) were dry. Patient satisfaction rate was 87.7% (n=57). With regards to complication rates, eight (12.3%) patients experienced complications of any Clavien-Dindo grade, of which four were a grade III due to one device migration (1.5%), as well as three explantations due to persistent leakage (4.6%). It is interesting to note that all four patients having undergone ATOMS explantation requested to have a reimplantation of the same device.
In our subgroup analysis, patients having received prior radiotherapy (n=22, 33.8%) had a lower improvement rate (73% vs 93%; p=0.03) as well as a lower dryness rate (45.5% vs 74.4%; p=0.02) than those having not received radiotherapy. Radiotherapy recipients also required more post-operative device adjustments (median 3.5 vs 2; p=0.01) and had a higher total instilled volume (median 18.3mL vs 13mL; p=0.01). There were no other statistically significant differences found in this subgroup analysis. Notably, differences in complication rates at any Clavien-Dindo grade, as well as the rate of patient satisfaction were statistically insignificant (Figure 1).
Eighteen (27.7%) patients presented with concomitant detrusor overactivity during preoperative urodynamic testing, with clinical overactive bladder being found in 16 patients (24.6%). Patients presenting with detrusor overactivity with clinical urgency symptoms alongside their post-prostatectomy incontinence had no pre-operative differences when compared with patients who had detrusor overactivity with no clinical OAB symptoms. Post-operatively, also no statistically significant difference was found in ATOMS outcomes in patients with detrusor activity with clinical OAB symptoms or in those without (Figure 2).
Interpretation of results
The AMS800, which is the most frequently implanted artificial urinary sphincter, may be considered the gold standard surgical treatment for post-prostatectomy incontinence (2). However, the ATOMS may be an excellent alternative. Our study demonstrates that the ATOMS is a safe and effective device in the treatment of post-prostatectomy incontinence, even when the majority of our patients presented with moderate to severe incontinence. We also found that the success rate of the ATOMS implantation seems to be unaffected by the presence of concomitant overactive bladder. Furthermore, in patients having received prior radiotherapy, dryness and improvement rates were less, and these patients required more adjustments and volume instillation.