Semirigid rod and malleable penile prostheses are implanted less commonly than multicomponent inflatable devices because of patient preference for more physiologic results with devices that inflate and deflate. Nevertheless, flexible devices may be preferred for complex reconstruction or when patients have significant issues with manual dexterity, require an implant, and use an external urinary collecting device. Three single-component flexible prostheses are available in the United States ( Table 123.1 and Fig. 123.1 ). Before insertion of a penile prosthesis, have proper sizers and sizes available and sterile, either in a sealed package or soaking in an antibiotic solution of bacitracin or rifampin. Make sure sizing instructions are available in the operating room (OR) and that a full complement of devices and backup devices is available.
|Name||Type||Company or Contact||Country|
|HR Penile Prosthesis||Malleable||Brazil|
|Virilis I and II||Nonmalleable||Giant Medical: www.giant-medical.com||Italy|
|Apollo Implant||Tissue expander||Giant Medical: www.giant-medical.com||Italy|
|Genesis Malleable||Malleable||Coloplast||United States|
|AMS Malleable 650/600M||Malleable||American Medical Systems||United States|
|AMS Dura II||Positionable||American Medical Systems||United States|
Approaches for Insertion
Although the subcoronal, penoscrotal, and infrapubic approaches are most commonly used, the penoscrotal incision is used by most surgeons. Implantation by the perineal approach takes longer and may increase the risk of infection because of proximity to the anus. Partial sensory loss into the glans can occur after making a distal penile incision even though the midline dorsal nerve is avoided. A circumcision is not usually necessary and may increase the risk of infection. If simultaneous insertion of an artificial urinary sphincter or male sling device is contemplated, separation of wounds (e.g., perineal and dorsal approaches) may reduce risk of simultaneous infections of prostheses in case one device becomes infected.
Start parenteral broad-spectrum antibiotics the day before an incision. Oral antibiotics for 7 to 14 days may be given postoperatively. Gram-positive bacteria such as Staphylococcus epidermidis are the most common pathogens in prosthetic infections. Patients may be instructed to scrub their genitalia in the shower for 10 minutes with povidone–iodine or chlorhexidine solution the night before surgery. Patients with remote active infections such as a urinary tract infection, decubitus ulcer, or osteomyelitis should have the infection treated before implant surgery. Shave or clip the genital area in the OR and scrub for 10 minutes with povidone–iodine or newer chlorhexidine–alcohol preparations. A sterile urethral catheter is inserted after the antibiotic preparation and removed as soon as the patient can voluntarily void. Antibiotics are administered intravenously 1 hour before the start of the procedure.
If a previous device is removed at the time of reinsertion of cylinders, extra irrigation with antibiotic solutions and povidone–iodine solution is helpful because the pseudocapsule of the cylinders can contain a biofilm colonized with gram-positive cocci. If the device is infected, a salvage procedure using seven irrigating solutions should be performed as outlined by Mulcahy.
Instruments needed include a basic set, Hegar dilators, small Army-Navy retractors, Weitlander and Brantley Scott ring retractors, an 18-French 5-mL silicone balloon catheter with a 12-mL syringe, a drainage bag and lubricating jelly, and bacitracin–neomycin irrigant. In patients with corporal fibrosis, Rosillo cavernotomes may be helpful.
If an inflatable penile prosthesis is to be replaced with a flexible one, infiltrate the base of the penis with lidocaine and begin with a penoscrotal incision. Remove the old prosthesis through incisions in the corpora. Most surgeons remove the reservoir to avoid late infections, but draining and retaining the reservoir has been safely performed in some patients.
Ventral Penile Approach
Anesthesia: Local anesthesia is helpful even with general anesthesia. Make a cutaneous penile block with long-acting local anesthetic such as 0.5% bupivacaine.
Incision: Begin with a 4- to 5-cm incision in the ventral midline of the penile shaft distal to the penoscrotal junction ( Fig. 123.2, A ). A transverse incision is also effective ( Fig. 123.2, B ) but is used usually for multicomponent devices to facilitate reservoir placement through the internal inguinal ring. Retract the incision distally to expose the dartos and Buck fascia in the midshaft of the penis. Grasp the subcutaneous tissue with small Allis clamps to act as retractors or place a Weitlaner retractor; spread the fascia and develop planes with vein retractors or place a Scott ring retractor. Dissect through each fascia layer using electrocautery and a tonsil clamp to develop and lift each layer from the tunica albuginea. Expose the urethra and corpus spongiosum and select an insertion site to one side of the urethra. Cauterize superficial vessels. If the corpus spongiosum is nicked, close it with a figure-eight 4-0 synthetic absorbable suture (SAS).
Place two stay sutures in the tunica albuginea and make a 3-cm incision between them into the corpus, beginning 0.5 cm from the distal end ( Fig. 123.3 ). Electrocautery is used to make this incision.
Use scissors to develop the initial subtunica plane proximally to the tip of the crura and distally to the glans penis, taking care to avoid perforation ( Fig. 123.4, A ). If corpora cavernosa are obliterated because of priapism, infection, or previous scarring, an Otis urethrotome or Rosillo cavernotome can be used to develop a channel for the implant. Stretch the corporal incision and insert a 10-mm Hegar or Brooks dilator or Dilamezinsert instrument until it fits well beneath the glans ( Fig. 123.4, B ). Progress through larger dilators, pointing the curve laterally, to 12 or 14 mm, depending on the type of prosthesis. Sponge forceps or careful dissection with a Kelly clamp may facilitate dilation under the glans ( Fig. 123.4, C ). Insert an 8- or 10-mm dilator proximally ( Fig. 123.4, D ), again taking care not to perforate the crus. Stop when the dilator is held up at the ischial tuberosity. It is unnecessary to use larger dilators proximally because the prosthesis is tapered.