The multicomponent three-piece inflatable penile prosthesis (IPP) is the most frequently implanted penile prosthetic in the United States ( Fig. 124.1 ). The original IPP was introduced in 1973 by Brantley Scott and associates. During the past 2 decades, engineering refinements in IPPs resulted in both improvements in function or device longevity and patient acceptance. Effective oral therapy for erectile dysfunction (ED) was introduced in 1998 with Viagra. With the introduction of oral phosphodiesterase type 5 (PDE5) inhibitors, the term erectile dysfunction has assumed center stage in popular culture, and the terminology and stigma associated with impotence faded into the background. There are an estimated 30 million men in the United States with ED. ED is associated with the risk factors of aging, diabetes mellitus, smoking, hypertension, and atherosclerotic coronary artery and peripheral vascular disease. First-line therapy for ED is an oral PDE5 inhibitor, with the majority of prescriptions being written by primary care providers. Urologic consultation is most often sought for men failing PDE5 inhibitors. Not surprisingly, demographic studies suggest a decline in penile prosthetics operations from 1998 to 2010. Mirheydar et al concluded that hospital-based penile prosthetic surgeries declined from 4703 (1998) to 2338 (2010). Over the same time period, the authors noted an increase in the proportion of penile prosthetics that were three-piece IPPs and increasing numbers of cases performed as outpatients.
Types of Penile Prosthesis
After oral PDE5 inhibitors, intracavernous injection therapies, intraurethral suppositories, and vacuum erection devices (VEDs), penile prostheses represent a third-line therapeutic option for patients with ED. The American Medical Systems (AMS) 700 series prosthesis and Coloplast Titan prosthesis are the only prostheses manufactured in the United States ( Fig. 124.2 ). The type of device chosen should incorporate both surgeon preferences and patient characteristics. Patient factors include abdominal girth, Peyronie disease, corporal fibrosis, spinal cord injury, and manual dexterity. The three-piece penile prosthesis is regarded as the “gold standard,” accounting for approximately 70% of all implants in the United States. Two-piece (Ambicor) and semirigid rods account for 20% and 10% of all implants, respectively. The three-piece IPP best simulates normal erection and flaccidity. IPPs provide excellent rigidity and flaccidity secondary to greater reservoir capacity, enhancing cylinder fluid emptying and shaft filling. Contemporary devices have mechanical failure rates less than 5% at 5 years, approaching 30% at 15 years.
The AMS 700 MS prosthesis is available in three cylinder types: CX, CXR, and LGX. The CX and CXR, which have a three-layer design (inner layer of elastic, middle layer of woven Dacron-Lycra, and an outer layer of silicon), provide girth expansion. The LGX, with a bidirectional weave, permits both girth and length expansion up to 20%. The CX cylinders should be used for men with ED and concomitant Peyronie disease. In the authors’ experience, penile straightening to within 15 degrees is accomplished with penile implant alone when Peyronie curvature does not exceed 45 degrees. A variety of surgical reconstructive techniques may be performed simultaneously with IPP; the most common is forcible manipulation of the inflated device in the opposite direction of penile curve, first described by Steve Wilson, MD. The multidirectional length and girth expansion cylinders of the LGX bend with penile curvature. The CXR cylinders can be used in revision surgeries associated with corporal fibrosis and for patients with smaller corporal dimensions. The LGX is capable of providing length expansion over time and is ideal in patients with good penile elasticity and is the authors’ prosthetic of choice in postprostatectomy ED. Patients must be counselled appropriately. In the authors’ practice, patients are instructed to intermittently inflate and deflate the IPP over the first 6 months. This “stretching exercise” is done in addition to resuming normal coital activity. I recommend inflating the device immediately before a shower and deflating afterward, at least three times a week. Patients are encouraged to count the number of pumps needed to achieve comfortable and functional rigidity; these should increase overtime as the tunica stretches to accommodate more filling.
Several design advancements in the AMS 700 series have facilitated device implant and longevity. These improvements include preconnected cylinders and pump, Conceal low-profile reservoir with Parylene coating for enhanced durability, a variety of Snap-Fit Rear Tip Extenders, and a Momentary Squeeze (MS) pump with one-touch button.
The Coloplast Titan prosthesis is available in two types: the Titan Touch and Narrow Body Cylinders. The Coloplast prosthesis differs from the AMS 700 series in terms of device design. First, the Coloplast prosthesis is constructed with an inert aromatic polyurethane polymer called Bioflex, which possesses a higher tensile strength and increased abrasion resistance compared with silicon. The two physical properties that make the Coloplast Titan cylinders ideal for the management of complex Peyronie disease are tensile rigidity and maximal cylinder diameter. The Coloplast CloverLeaf reservoir assumes a cloverleaf configuration when deflated, facilitating placement. The cylinder input tubing exits at a zero-degree angle, permitting smaller corporotomies and deeper seating of the rear cylinders with less dissection or dilation. The Coloplast IPP contains a Lock-Out valve to prevent autoinflation. Henry et al have demonstrated that the Titan IPP cylinders can also increase patient perception of length. Achieving optimum satisfaction with perceived penile length requires aggressive cylinder sizing at the time of implant (minimizing rear tip extender and maximizing inflatable cylinder length) and rehabilitation for the 12 months (with intermittent inflation and deflation).
Preoperative Preparation
A thorough history and physical examination should be done before any surgery. Prior surgical interventions should be documented because they may impact the choice of incision and details of surgical intervention. Reservoir placement is more complicated in men with prior abdominal surgeries. History and examination should identify prior bilateral inguinal herniorrhaphies, prostatectomy, cystectomy, and proctocolectomy. Each of these poses specific challenges to placement of IPP reservoirs. Cardiology or endocrinology consultation preoperatively may be indicated for men with severe vascular ED and associated heart disease or diabetes mellitus (hemoglobin A1C [Hgb A1C ] ≥8.0 mmol/mol). Men on chronic anticoagulation need specialty assessment to determine their risks for coming off anticoagulation. Depending on the form of anticoagulation, patients should optimally be off new oral blood thinners for 3 to 5 days and remain off those agents for 10 to 14 days postoperatively. Scrotal hematoma is an invariable consequence of IPP. For men who cannot come off anticoagulation, consideration should be given to another trial of conservative therapy with high-dosage penile injectable agents (Trimix) or VEDs.
Preoperative consent should be obtained for all patients with specific mention of complications, including bleeding, infection, device malfunction, erosion, and patient dissatisfaction. The number one complaint after IPP is that the penis is not as long or as big as it used to be. Shaft dimensions do change with aging secondary to decreasing content of smooth muscle and increasing content of collagen. Men with postprostatectomy ED are at significant risk for penile shortening. A specific discussion regarding penile length and size are important to “set” patient expectations. For men with severe ED who report no nocturnal erections and express concerns about penile length, I recommend several months of penile stretching by VED. The VED is cycled on/off for 15 minutes daily without application of the constriction band. Preoperative urinalysis and culture should be free from infection. Urinary irritative or obstructive symptoms should be evaluated with uroflow and postvoid residual testing. If any surgical management of benign prostatic obstruction is entertained, that surgery should be done well in advance of IPP followed by several months of convalescence to permit restoration of normal voiding patterns. The night before and morning of surgery, patients should shower with antibacterial soap.
Infection Prevention
Urologic prosthetic surgery has a heightened risk of infection. Although the literature remains controversial as to the predictive value of Hgb A1C , at Mayo Clinic Florida the Surgical Quality Committee has set a cutoff for elective prosthetics, Hgb A1C below 8.0 mmol/mol. Above this level, patients receive dietary counseling and endocrinology consultation, and surgery is put on hold. Hgb A1C may take several months to drop on new dietary or hypoglycemic regimens.
The AUA Best Practice Statement on Urologic Surgery Antimicrobial Prophylaxis (2008) mandates an aminoglycoside and first- or second-generation cephalosporin or vancomycin perioperatively to include coverage for both gram-positive and gram-negative microorganisms. It is our preference to use combination intravenous vancomycin and gentamicin given 1 hour before surgical intervention. In May 2001, AMS began to manufacture all penile prosthetics with a rifampin–minocycline coating (InhibiZone), inhibiting bacterial growth after surgery, including both Staphylococcus epidermidis and Staphylococcus aureus . The drug-eluting aspect of this implant is relatively short-lived, with significant decreases in rifampicin and minocycline after 1 and 7 days, respectively. The Coloplast IPP components are coated with a hydrophilic substance that reduces bacterial adherence when activated with aqueous solution immediately before implantation. The hydrophilic coating of the Coloplast IPP can also be activated by dipping in antibiotic solution; in vitro studies show elution of drug and inhibition of bacteria. The hydrophilic Titan Touch IPP is lubricious when wet and must be handled carefully. All components of the Titan are coated. Recent literature comparing patients receiving first-time IPPs with those receiving AMS InhibiZone rifampin–minocycline or Coloplast Titan dipped in rifampin–gentamycin shows statistically similar infectious rates (≤1%).
In terms of patient preparation, preoperative male genital hair removal with a razor results in significantly less skin trauma and better hair removal than hair clippers. In a comparative trial, there was no increased risk of surgical site infections with scrotal shaving. The Sexual Medicine Society of North America has a position statement advocating scrotal hair removal by razor by the surgeon at the time of operation ( www.smsna.org ) The authors recommend a mechanical skin cleansing with betadine scrub followed by chlorhexidine–alcohol (ChloraPrep) paint before incision. Chlorhexidine–alcohol solutions should be allowed to dry for 3 minutes before applying drapes to avoid Bovie ignited fires.
Operating Room Equipment
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Proprietary assembly kit, reservoir, and cylinder sets should be opened and prepared on a separate Mayo stand with plastic covering. Manufacturers recommend not preparing or storing the prosthetic components on cloth or paper drapes. The authors’ preference is for a large basin filled with a dilute solution of polymyxin–Polysporin for frequent glove cleansing, removing blood before handling prosthetics. The Lone Star, Furlow Inserter, and disposable Deaver retractors are left soaking in this basin until ready for use.
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Open the assembly kit before skin incision, and prepare four to six mosquito clamps with the silicone tubing provided. The authors’ preference is for the scrub technician or resident to delay opening and prepping of the reservoir until the surgeon is ready to implant.
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Fill two 60-cc and two 30-cc syringes with sterile injectable saline. Attach proprietary filling tips to all four syringes.
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For Coloplast Titan, have antibiotic dipping solution in a labeled kidney basin and a second kidney basin with injectable normal saline. For AMS InhibiZone product, stock a filling basin with saline for filling and a second basin for wetting the prosthetic immediately before implantation.
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Follow the manufacturer’s device preparation guidelines for prosthetic assembly.
Recommended Operating Room Setup
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Separate Mayo stand for sterile preparation of penile prosthetic
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Wash basin for cleansing gloves before handling of the penile prosthetic
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Additional sterile gloves
Instrumentation
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Retractors: Deaver, Vein retractor, Army-Navy
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Tissue forceps: DeBakey, Addison
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Mosquito clamps with and without rubber “shods”
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Metzenbaum and Mayo scissors
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Babcock and right angle clamps
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Foerster lung clamp (for ectopic reservoir placement)
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One #15 for skin and #12 scalpel blade for corporotomies
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One pediatric suction tip
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Kittners or peanuts
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1 Furlow insertion tool
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Hegar dilators, Uramix cavernotomes, and Brooks dilators
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One graduated pitcher with sterile saline
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One Asepto irrigation syringe
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Two 60-cc Luer lock syringes
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One 10-cc Luer Lock syringe for irrigation before connection
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One 14-Fr Foley catheter, catheter plug, and drainage bag
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One Jackson-Pratt drain
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Flexible cystoscope and video tower
Draping
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One lap pack
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Six sterile towels
Solutions
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250 mL of sterile, isotonic, sodium chloride USP solution for device filling
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1000-mL noninjection sterile saline
Surgical Approaches
Multicomponent IPPs can be implanted via an infrapubic or transscrotal approach. Individual surgeons cite a variety of preferences for each approach, but there is no enhanced safety of one over the other. Beyond preference and experience, patient factors may dictate the approach. In the current literature, the transscrotal approach is favored approximately 80% of the time. Both approaches are described in detail in this chapter. Briefly, the transscrotal approach allows for greater proximal crural exposure, avoids dorsal nerve injury, and allows direct visualization of pump placement. However, reservoir placement is performed blindly, which can be especially tricky in patients with prior abdominal surgery. In contrast, the infrapubic approach allows for reservoir placement under direct vision, avoids scrotal dissection, and may be completed in a shorter time than the penoscrotal approach, but dorsal neurovascular bundle injury is a significant concern and devastating complication.
Penile prostheses are performed under general, spinal, or epidural anesthesia. Local anesthesia can enhance recovery but is rarely the performed in multicomponent implant placement (pudendal nerve block combined with penile block instilling 1% lidocaine directly into the corpus cavernosum).
Implantation of AMS 700 LGX or Coloplast Titan Inflatable Penile Prosthesis via Penoscrotal Approach
Preliminary Dissection and Cylinder Sizing
The patient is prepped and draped in a sterile manner and placed in supine position with the legs slightly flexed and abducted. The authors’ preference is for the low lithotomy position in Allen stirrups ( Fig. 124.3 ). A 16-Fr Foley catheter for novel cases or 14-Fr Foley catheter for revisions is placed sterilely, and a ChloraPrep mini stick is used to clean the exposed Foley catheter after insertion. Gloves are cleansed in basin to minimize contamination with intraurethral bacteria.
