The implant consists of a silicone elastomer balloon, connected to a self-sealing port by a 2 lm conduit (Fig. 2). The tip of each balloon has a radio-opaque marker that can be easily visualized under fluoroscopy to confirm the correct position. The conduit carries 1 lumen to connect the balloon with the port to fill the balloon, while the other lumen is occupied by a push wire, in order to stiffen the device during the implantation. Normally two balloons will be used at initial implantation. The titanium port is designed to self-seal during the filling or withdrawal of fluid from the balloon.

In order to facilitate implantation, special instruments are provided (Fig. 3). The U-shaped sheath can carry a sharp stylete for perforation of the pelvic floor, a blunt one to open layers above the pelvic floor and the tissue expansion device (TED) do develop and increase space for to hold the balloon.

The patient is prepared and placed in the lithotomy position under general, spinal, or local anesthesia. Fluoroscopy is attached and the balloons are evacuated from air. After cystoscopy the bladder is emptied and filled with 100 cc of contrast solution via the rigid cystoscope in order to visualize the bladder and bladder neck. The cystoscope is retained to maintain a straight horizontal positioning of the urethra.

Two small perineal stab incisions (alternatively one 2 cm transverse incision) are made on each side of the urethra. A hemostat is now used to subcutaneously palpate the ipsilateral inferior ramus of the pubic bone and the rigid cystoscope sheath for orientation. Fluoroscopy provides further topographic information. Once the correct entry point in a small triangle between the urethra (cystoscope) and pubic bone is identified, the pelvic floor is perforated ca 1 cm paraurethrally using the sharp trocar. Parallelity of cystoscope and trocar in fluoroscopy help avoiding urethral trauma (Fig. 4). When the pelvic floor has been passed, the blunt trocar and the TED are used to develop and define the spot for balloon position (Fig. 5). This should be close to the bladder neck after RPE or next to the apex in patients with the prostate in place (after TURP, external beam radiation therapy (EBRT)). Finally the inner part of the trocar (TED or stylete) is removed and the balloon put in place with the help of the push wire. Attention should be paid to make sure the wire reaches the tip of the balloon. The balloon is then inflated with 0.5–1 ml of isotonic contrast using a non-corning needle, and the U-shaped trocar is removed while securing the balloon position with the push wire. The procedure is repeated on the contralateral side. Correct position of the balloons as well as slight narrowing of the urethra may be confirmed by a UCG (Fig. 6). Now the push wires may be removed. Finally the ports are buried superficially in the sub-dartos fascia in the anterolateral wall of the scrotum, in order to enable percutaneous adjustment after surgery. Wounds are closed after rinsing with antibiotic solution. A 14Fr Foley catheter is inserted for 12 h.

In the rare case of intraoperative bladder perforation, a new position for the balloon has to be established, and the Foley is left for 5 days. If the urethra has been perforated, the implantation on this side has to be abandoned. It may be approached again after 3 months; however, many patients may be cured with unilateral placement of a balloon.

In 2006 an alternative implantation technique was described by Gregori, implanting the balloons under transrectal ultrasound (TRUS) guidance [2]. Namely, when doing the procedure in local anesthesia, this novel approach carries advantages, as the anesthetic can already be injected under sonographic control. The initial incision is similar to the one described above. The progression of the trocar is controlled with TRUS guidance using a 7.5 MHz linear and small convex probe. The trocar is inserted through skin incision and directed to one side of the bladder neck, perforating the pelvic diaphragm. The layers may additionally be opened injecting ca 10 ml saline at the bladder neck through the trocar with a long puncture needle. This maneuver can well be monitored by TRUS. With the US-guided approach instead of a rigid cystoscope, a Foley catheter may be used making the possibility to perform the procedure under local anesthesia even more likely. Ultrasound allows an excellent visualization of the catheter and the surrounding anatomical structures. Placement of the balloons finally works just as described above.

According to the healthcare system, the procedure can be performed as an outpatient therapy. At any rate antibiotics should be applied for 4 days minimum. The Foley is removed after 12 h. Some patients might show improved continence due to postoperative swelling but usually become incontinent after the edema has subsided. Adjustment can be started 4–6 weeks later, when the pseudo-capsule has formed around the balloons (Fig. 7). Further adjustments can be made in 3–4 week intervals until total continence is achieved. Adjustments should be limited to 1 ml per balloon per visit, to minimize pain and the risk of migration. Balloons can be inflated to a volume of 8 ml. The device can be deflated if the patient develops obstructive voiding difficulties.