Preoperative evaluation

Evaluation of patients for treatment with an AUS starts with a comprehensive office visit, including taking a history and performing a physical examination, urinalysis, and urine culture. Each patient completes a 72-hour voiding diary and a 24-hour urinary pad weight test that is brought to the office visit. The pad-weight study is an invaluable objective measure of the magnitude of the incontinence. During the office visit, videourodynamics are performed. This step, along with the voiding diary and patient history, helps confirm the factors contributing to the incontinence and identifies factors that may mitigate against a good outcome. Some investigators have suggested that urodynamic study is superfluous to the selection of the patient for implantation, but the authors disagree. Cystoscopy is performed in all patients to evaluate the urethra for a healthy placement site and to exclude urethral strictures and anastomotic contracture.

Preparation

The authors attempt to ensure that the urine is sterile and that infected foci are not present the week before surgery. Preoperative antibiotics (an aminoglycoside and cephazolin or vancomycin) are given intravenously. Surgery is conducted under general or spinal anesthesia with the patient in the low lithotomy position and with the entire operative site shaved. Before draping, a 10-minute, iodine-based skin preparation is performed that includes the lower abdomen, genitals, and perineum. A 16-French Foley catheter is placed to drain the bladder and to facilitate identification and dissection of the urethra, which is the first step of the procedure.

Preparation

The authors attempt to ensure that the urine is sterile and that infected foci are not present the week before surgery. Preoperative antibiotics (an aminoglycoside and cephazolin or vancomycin) are given intravenously. Surgery is conducted under general or spinal anesthesia with the patient in the low lithotomy position and with the entire operative site shaved. Before draping, a 10-minute, iodine-based skin preparation is performed that includes the lower abdomen, genitals, and perineum. A 16-French Foley catheter is placed to drain the bladder and to facilitate identification and dissection of the urethra, which is the first step of the procedure.

Cuff placement

The ideal site for placement of the AUS cuff is at the bulbar urethra just proximal to the bifurcation of the corporal bodies ( Fig. 1 ). Bucks fascia is incised, as it reflects off the bulbar urethra onto the diverging corporal bodies. A tunnel can be made using scissor dissection, dorsal to Buck’s fascia over the roof of the urethra as it passes between the separating corporal bodies. A right-angle clamp may be passed atraumatically through this tunnel while avoiding the dorsal aspect of the urethra ( Fig. 2 ). Blunt or spread dissection can be hazardous in this area, as it risks the thinning of the urethra or splitting into the urethra. Being posterior to the bifurcation of the corporal bodies is important in that it allows for a safer dissection dorsal to the urethra and presents a larger urethra.

The proper placement of the AUS cuff at the proximal urethra. The divergent corporal bodies protect the cuff from inadvertent activation when sitting. This location is reached easily with the patient in low lithotomy and can be felt before incision as the area where the urethral catheter is no longer palpable in the perineum.

( A ) The urethra is held gently and pulled away from the corporal body. ( B ) Buck’s fascia is incised sharply as it reflects off of the bulbar urethra. This step allows clean, sharp dissection of the ventral urethra under direct vision ( C ) and provides protection from injury during manipulation ( D ).

Generally, a 4.0- or 4.5-cm AUS cuff is selected, and a cuff that has the snuggest fit, but is not obstructive, results in better continence ( Fig. 3 ). The circumference of the urethra at the dissected site is measured in centimeters to guide selection of cuff size. The authors believe that the measurement should be taken on a bare corpus spongiosum, as intervening fat or muscle rapidly atrophies, causing leakage of the device. Other than when implanting a transcorporal cuff, the cuff size is always smaller than the measured circumference of the urethra, because much of what is measured around the urethra is compressible spongy tissue and because postoperative subcuff atrophy will occur. Although no accurate guide can be given, generally if the corpus spongiosum measures 5 cm, the authors implant a 4-cm cuff.

For good function, the cuff should fit snugly around the bulbar urethra.

The best test of cuff fit is the visual and endoscopic appearance after it has been placed around the urethra. If the measurement was incorrect, it is often obvious (the cuff looks obviously too loose or is strangling the urethra). At this point, the cuff should be changed, regardless of waste of equipment. If the margin of tightness is small, cuff size can be increased by a few millimeters by excising up to 2 mm from inside the tab. Caution must be used in performing this unapproved maneuver, as removing too much from the cuff tab may create a hole that is large enough to cause herniation of the cuff through the tab hole and malfunction of the device. The authors routinely perform urethroscopy after urethral dissection and cuff placement to ensure an absence of dissection injury to the urethra and to confirm good cuff sizing.

The tubing to the AUS cuff is passed from the perineal dissection using a transfer trocar or a tonsil clamp (underneath Colles’ fascia and staying close to the pubic bone) to the right lower quadrant abdominal wound where the incision is located for placement of the reservoir and scrotal pump. Throughout the procedure, the operative site and the components periodically and liberally are irrigated with an antibiotic solution.