The initial clinical experiences to be published appeared a few years after its development. The Austrian study by Seweryn et al., which included 38 patients since 2009 was among the first (11). The authors reported continence success (defined as maximum one pad per 24 hours) at 60.5%. Since that report, the device has undergone modifications, most notably in 2013 with a silicone rather than titanium port cover and after 2014, this could be placed in the scrotum with the port pre-attached. This element along with its mesh arms and silicone cushion form key characteristics that distinguish it from adjustable male sling alternatives such as the Remeex system (Neomedic, Spain), consisting of a suprapubic pressure adjusting device (“varitensor”) connected via two traction threads to a suburethral prosthesis made of polypropylene and the Argus sling (Promedon, Argentina) (6, 12). The latter features a silicone cushion pad to compress the bulbar urethra, cone shaped columns on either side and “washers” to secure tension (13).

The switch to a silicone covered port was driven by early reports of device explantation as a result of reported titanium intolerance (14). The transition away from the inguinal port placement has reduced the total number of incisions required from two down to only one. The 3rd generation port is also smaller. In a multi-centre study from Germany and Spain, port related complications were 19.2% with the first device but 6.5% with the 3rd generation model (15).

In a recent series by Giammò et al., the mean operative time was 51 min, and most studies report similar results that total operative times under 60 min (16). Hospital discharge is usually planned for within 24 h and adjustments can be made to the port in the outpatient setting. In a recent systematic review, the mean number of fillings required was 2.4 (17).

In a 2019 meta-analysis of pooled data from 1,393 patients (20 studies), 90% were found to have symptom improvement at follow up (18). Sample sizes of the included studies ranged from 13 to 287 patients. Seven of the included studies reported patient satisfaction and rates ranged from 61.8% to 100%. Interestingly, in the study with a satisfaction rate of 61.8%, 39% of the sample had undergone previous radiotherapy and the explantation rate was 31.5% (19). In contrast, in the study recording 100% satisfaction, only 7.7% had received previous radiotherapy and the explantation rate was zero (20). More research is needed to determine what affects long term patient satisfaction.

Pooling data on dryness rates is difficult given the varying definitions for this parameter. In a retrospective study of 155 patients by Angulo et al. published in 2020, which had a mean follow up of 60 months, 72.1% achieved a dry status as defined by no pads or one security pad (21). Friedl et al. reported on the impact of ATOMS^TM on sexual function (22). Erectile function scores were improved at six months follow up and 38% of the sample started to have intercourse again after having stopped previously. Dual implantation of penile prosthesis and ATOMS^TM has been reported. To date, only data on simultaneous AUS placement at the time of surgical repair of refractory bladder neck contracture has been reported (23–25).

Muhlstadt et al. reported the overall complication rate to be 27.3% in their series of 187 patients. The authors found previous radiotherapy as well as previous urethral surgery to be significant predictors of a post operative complication (15). The learning curve associated with ATOMS was also studied and found the rate of complication to fall from 44% to 21.1% after 25 cases were performed. Angulo et al. reported an explantation rate of 8.5% in their multi-centre study of 902 patients (26). The two commonest indications for removal were persistent incontinence and port erosion. Explantation rates do vary, with reports of as high as 19% previously recorded (27). Possible reasons for such wide variations include different follow up lengths and the proportion of patients with radiotherapy. Giammo et al. reported the survival of the ATOMS^TM device to be 97% at 12 months and 89.9% at 60 months (28). As with all prosthetic devices, infection can be a major complication and rates between 2.7%–6.2% have been reported (8). Predictive nomograms have become increasingly popular across many areas of urology and tools are now available in the setting of ATOMS^TM (29, 30). This includes the tool developed by Dorado et al., which serves to predict risk of failure (30). Variables included in that tool are Male Stress Incontinence Grading Scale (MSIGS), 24-h pad test and history of radiotherapy.

While ATOMS^TM surgery is covered in the latest EAU guideline, no formal recommendations regarding any of the adjustable male slings are given as the panel determined the current body of literature to be still lacking (31). Fixed male slings do however receive a recommendation. Here it is stressed that the role of such fixed devices should be limited to the setting of men with mild to moderate incontinence. Again however, it is underscored that the evidence is also limited for this intervention type. The American Urological Association guidelines do not make any specific comment regarding the ATOMS^TM device (2). Male slings as a group are discussed with a similar recommendation that they are avoided in the setting of severe incontinence. These positions shared by the EAU and AUA guidelines are very similar to those from the Urological Society of India, Canadian Urological Association (CUA) and the International Consultation on Incontinence (ICI) (32–34). Of note, some of these guidelines are not updated yearly. The CUA document was disseminated in 2012, which was before the last generation of ATOMS^TM was released and there have been multiple original studies published since then (32). Bhatt et al. evaluated all five of these guidelines on the topic of post prostatectomy incontinence using the Appraisal of Guidelines for Resarch and Evaluation II (AGREE II) tool on domains such as scope, clarity and applicability (35). The authors concluded the AUA guidelines to score highest.

There are several advantages that can be found with the ATOMS^TM device. Firstly, and in contrast to fixed slings such as the AdVance™ and the AUS, adjustments can be made without the need to return to surgery and the scrotal port placement allows for ease of access when doing so. Also, if there is a complication that is localised to the port only, the port can be removed in isolation. While this means that further adjustments cannot be made, it avoids the complete explantation of the device. ATOMS^TM is also associated with a shorter operative time compared to AUS. In a propensity-score-matched analysis comparing the two devices, the mean operative time associated with ATOMS^TM was significantly shorter (56 vs. 100 min, p < 0.001) (36). In contrast to AUS where satisfactory manual dexterity and cognition is required, patients are not required to manipulate the ATOMS^TM device themselves. While simpler methods for activation of the AMS 800 have been proposed, these are not yet in clinical use. Even if patients have normal cognition and dexterity at the time of surgery, if they later suffer an acute medical event such as a stroke that impairs their upper motor function and/or their cognitive status, this can pose obvious problems for those with an AUS in situ. From a practical perspective, patients with AUS also require greater caution when performing a subsequent cystoscopy as well as the need for a urologist to attend the operating theatre to deactivate the AUS device if undergoing surgery by another specialty when catheterization is being performed. From an anatomical perspective, the non-circumferential design reduces the risk of urethral atrophy and erosion. Infection rates are also lower when compared to AUS as well as Argus and Remeex. There is a potential cost advantage too, with Constable et al. reporting costs associated with ATOMS^TM procedure to be £6,000 compared to £9,000 with the AUS (37).

However, as raised by international guidelines, the levels of evidence supporting the role of ATOMS^TM is more limited compared to AUS. This is perhaps the biggest disadvantage. How these abovementioned advantages translate overall is thus yet to be fully determined.

While the body of original studies for ATOMS^TM does exceed 20, many are single centre and retrospective in nature and to date, there have been no randomised studies, which have placed ATOMS^TM head-to-head against AUS. The MASTER trial did compare male slings with AUS but most of the slings included in that non inferiority trial were the fixed type and a full breakdown is not given (38). The authors found no differences in SUI burdens at follow up. However, secondary outcomes such as complication rates did favour AUS. The proposed advantages of the AUS are its feasibility in patients with previous radiotherapy and those with severe SUI.

Beyond the abovementioned lack of studies in comparison to other incontinence devices, other challenges exist. For example, the lack of standardised reporting as well as lack of consensus regarding reporting of SUI. Some author groups prefer to use pad count while others choose pad weight. Furthermore, for each one of these, consensus is lacking regarding how to how to grade severity. This makes comparisons between studies more difficult. Another area that appears to lack standardisation is reporting of port removal/total explantation. For example, some groups report this as a complication but others consider it a late treatment failure. Unless a reader studies the results very carefully and is aware of this, one can easily misinterpret the complication burdens across different studies.

Heterogeneity in other forms is also common among studies. For example, populations with both RP and benign prostate surgery patients and some having had radiotherapy. Furthermore, radiotherapy type (e.g., adjuvant vs. salvage) is not routinely specified in these studies. Studies reporting their experiences with ATOMS^TM over several years will usually include patients have had different generations of ATOMS^TM devices. This can introduce further bias.