Ajay Singla and Craig Comiter (eds.)Post-Prostatectomy Incontinence10.1007/978-3-319-55829-5_12

New Technologies in the Management of Post-prostatectomy Urinary Incontinence

Neha R. Malhotra¹ and Y. Zaki Almallah¹

(1)

Department of Urology, University of Illinois at Chicago, CSN Suite 515 M/C 955, 820 S Wood St., Chicago, IL 60612, USA

Y. Zaki Almallah

Email: yzam@hotmail.com

Keywords

Post-prostatectomyUrinary incontinenceNew technology

Abbreviations

AMS

American Medical Systems

ATOMS

Adjustable transobturator male system

AUS

Artificial urinary sphincter

PPI

Post-prostatectomy incontinence

TMOD

Tape mechanical occlusive device

Combined Compression and Adjustable Systems

Traditional slings offered fixed compression of the sphincter or an area just distal to it but were only suited for mild to moderate incontinence [1, 2]. Newer, adjustable transobturator systems offer higher degrees of compression, which can be increased as needed and do not require manual dexterity or cognitive capabilities needed to operate an AUS. Furthermore, the lack of mechanical parts nullifies the risk of mechanical failure [3]. Of these, the one that has gained the most traction around the world is the adjustable transobturator male system (ATOMS, Agency for Medical Innovation, Feldkirch, Austria). It has been approved for use in Europe since 2008. Unlike other devices, ATOMS is both anchored and adjustable.

ATOMS consists of a macroporous, monofilament propylene mesh arms that are affixed using suture, an adjustable central silicone cushion, and titanium port for percutaneous adjustment [3]. Four-point fixation of the central cushion to the mesh arms using suture allows for even distribution of pressure and avoids dislocation [3]. The central cushion is placed over the distal bulbospongiosus muscle to provide indirect compression of urethra while having a decreased risk of erosion [4]. This may prove advantageous in men who have, or will undergo, radiotherapy as part of their cancer treatment. As initially described, ATOMS is placed through a midline vertical perineal incision carried down to expose the bulbospongiosus muscle, and a space is then created toward the ischiocavernosus muscle [3]. Helical tunnelers are then used to pass the device through the obturator foramen in an outside-in technique, and the mesh arms are drawn back to secure the system to the inferior pubic rami [3]. The titanium port for percutaneous adjustment was placed in the symphysis region, but may also be placed in the scrotum [5]. In early studies, the mean operative time was less than 1 h, and in the most recent results, experienced surgeons can implant the device in less than 30 min [3, 6].

The initial Austrian study of 38 patients had an approximately 60% dry rate, 24% improvement, and 16% failure (more than two pads daily); this study did include men with mild, moderate, and severe post-procedural incontinence; however, the mean preoperative pad used was 6.8 [3]. A multicenter European study with 99 patients corroborated these results with 63% of patients being dry [7]. In the initial study, four patients were dry with just one adjustment, but in total a mean of four adjustments occurred in the mean follow-up period of 17 months. The most common complication was pain, and only one device required explantation [3]. Longer-term follow-up at this institution and other institutions showed a 15% explantation rate (9/62) but maintained the 61% continence rate [8]. They found that, in addition to other factors, severe PPI was a risk factor for failure to achieve continence [8]. A smaller, retrospective study in Spain showed 12 out of 13 patients (92%) with mild to moderate continence dry at 16-month follow-up, suggesting this technique is reproducible [5]. The most recent multicenter results with the third generation of the device are consistent with prior results and continue to have a dry rate of around 61%, but now the total explantation rate is nearing 20% [6]. Interestingly, the most common reason for explantation is cited as titanium intolerance; other reasons include device dysfunction, infection, dislocation, and persistent pain [6].

These results are encouraging, but there is some concern about the rate of explantation and the number of patients reporting pain. Nevertheless, the overall concept is novel and more long-term data are awaited.

Compressive Devises and New Sphincters

Though ATOMS has perhaps gained the most support as a mechanical sphincter alternative with the potential to treat severe PPI, there are other devices that provide complete or partial urethral occlusion. These include alternate sphincters and tape that can be activated. Again the concepts of these new devices are very innovative but the experience with them is still very limited. Larger-scale studies, preferably randomized controlled trials, are the only way forward for these devices to become acceptable in the mainstream clinical practice.

FlowSecure

The popularly used AMS 800 AUS is known to have a high learning curve for implantation, and as such, some of the newer sphincter attempts such as the FlowSecure (Barlow Scientific Limited, London, United Kingdom) and the Zephyr ZSI 375 (discussed later) offer preassembled circuits to decrease operative time and improper connections or implantation [9]. The FlowSecure, developed by Michael Craggs and Anthony Mundy, offers a one-piece silicone device free of tubing connections and includes a urethral cuff, a pressure-regulating balloon, a stress relief balloon, and a control pump [9, 10]. The unique feature of this device is the stress release system, designed to respond to transient increases in intra-abdominal pressure by increasing urethral occlusion, but requires an additional balloon as compared to the AMS system. The extraperitoneally placed stress relief balloon is designed to provide conditional occlusion. As with the traditional AUS, both a perineal and an abdominal incision are made for placement of the device. The pressure can be altered by injecting or removing fluid percutaneously after implantation, a potential advantage over the AMS system [10]. The preliminary study of nine patients showed a decrease in mean leakage from 770 to 55 mL [9]. At 6-month follow-up, all patients who were using pads preoperatively and were still enrolled in the study were noted to have continued, though decreased, pad use. Initial experience did show mechanical issues in two of the nine implants, but since that time the device has been reengineered [9].

Zephyr ZSI 375

Another artificial urinary sphincter alternative is the ZSI 375 (Zephyr Surgical Implants, Geneva, Switzerland). Marketed as a one-piece sphincter, it consists of an adjustable urethral cuff pre-connected to a pump and a pressure-regulating tank [11]. Like the AMS 800, it requires both a perineal incision for cuff placement and an inguinal incision for pump and tank placement. There is no abdominal reservoir. The device consists of not only a hydraulic circuit but also a pressure-regulating compensation circuit. The device is prefilled with 9 mL of saline (4.5 mL in each circuit) on the back table prior to implantation, but later injection of saline into the pouch can be used to increase pressure. This is similar to the FlowSecure sphincter and a potential advantage over the AMS system [10]. Urethral closure pressures range from 60 to 100 cmH₂O. In an early, retrospective study of 36 men, 26 (73%) of men experienced gain of social continence, defined as less than or equal to one pad use per day, but only 4 (11%) were completely dry, requiring no pads [11]. Four devices were removed, one for erosion and three for infection [11]. While the Zephyr ZSI 375 may offer a simpler surgical placement due to the lack of the abdominal reservoir, it fails to show comparable dry rates to the current AMS 800, and the most recent results show a rate of explantation over 60% for reasons such as mechanical defect, infection, pain, and erosion [12].

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