Technical Considerations in Penile Prosthetic Surgery

Preoperative considerations Patients are admitted to the hospital either the evening before or the morning of the operation. The shorter the hospital stay, the smaller the risk of contracting infections from hospital contamination. The urine culture should be negative at the time of surgery [14,55].

Antibiotic prophylaxis is used routinely. Intra- venous administration of the first dose of the antibiotic should be completed at least one hour before the skin incision to ensure having adequate serum con- centrations of the antibiotics at the time of surgery. There is no general agreement on the antibiotic regimen to be used. It is advisable to use the antibiotic recommendations of the hospital in which the surgery is performed. The most common germs involved are Staphylococcus species, particularly Staphylococcus epidermidis, and gram negative enteric bacteria. One commonly used antibiotic regimen is a cephalosporine during the hospital stay followed by oral ciprofloxacine for one week after discharge [55]. Some clinicians prefer to use vancomycine and rifampicin [14]. Other clinicians use other combinations.

Genital shaving should be performed in the operating room immediately prior to surgery to avoid contamination of the incision. Shaving should be followed by a fifteen minute surgical scrub with iodopovidone [55]. Traffic within the operating room should be minimized to reduce the risk of infection. Proper sterile technique, minimizing tissue trauma, short operating time and effective wound closure, are also well known to reduce the risk of perioperative infections [26].

Operative considerations The surgical approach may differ according to the type of implant used, the surgeon’s preference and the previous surgical history of the patient. Semi- rigid prostheses may be implanted either subcoro-

Surgical Treatment of Erectile Dysfunction 141

nally, infrapubically or scrotally. Inflatable implants may be implanted either infrapubically or scrotally. There is no evidence that any one surgical approach is best [27]. The transverse scrotal approach allows excellent exposure of most of the length of the corpora cavernosa. With this approach, the crura of the corpora cavernosa may be easily exposed as far back as the ischial tuberosities. This posterior exposure may be important when there is severe scarring of this segment of the corpora. At the same time, the distal part of the corpora may be easily exposed by degloving the penis from the surgical incision [14]. A ring retractor with hooks placed at the skin edges sig- nificantly facilitates the exposure of the surgical field. This retractor should be available during these procedures. Placement of a urethral catheter may be of help in identifying the urethra. In addition, if the reservoir is placed in Retzius’ space, the bladder should be emptied first to minimize the risk of inad- vertent bladder injury. During the procedure the surgical field should frequently be irrigated with an antibiotic solution such as gentamycin. Dilating the corpora cavernosa is a key step of the procedure. Dif- ferent dilators are available; each surgeon should use the one with which he or she feels most comfortable. Hegar and Brooks dilators are useful in most cases, while Rossello dilators are of particular value when managing fibrotic corpora cavernosa [28]. The narrow base three-piece implants mentioned above are helpful in these cases, as they only require dilation up to 10 mm. A major advantage of using narrow-base implants is that they avoid the need for

a synthetic patch to close the corporotomy. This may occur, when a conventional three-piece implant has been placed in severely fibrotic corpora cavernosa.

Measuring the length of the corpora cavernosa is important to avoid developing penile deformities after surgery. The use of the Furlow inserter to measure the length of the distal and proximal part of the corpora cavernosa is very helpful. The sum of the proximal and distal measurements minus 1 cm is the length of cylinder that should be implanted. Gener- ally the shorter length should be chosen when there is doubt between measured lengths (e.g. choose an

18 cm cylinder if the length of the corpus cavernosum is 18.5 cm). Montague et al. [29,56] have pro- posed that the length of cylinders should be 2 cm less

than the measured corporal length in order to avoid pain and deformities from over-sizing of the cylinders. Ultrex cylinders, which can lengthen with inflation should be sized 1 cm less than measured corporal length. Semi-rigid rods should be sized about half a centimeter less than the measured corporal length [25]. Proper prosthesis width is also crit- ical for optimal support for erection. If the 12 mm dilator is snug, it is more appropriate to use a narrow cylinder, as the fully expanded standard inflatable cylinders reach at least 18 mm in girth [25].

Rear tip extenders may be used to achieve the desired length of the cylinders. In cases of severe fibrosis of the crura, it is better to choose a shorter cylinder and add several centimeters of rear tip extenders to achieve the desired length. The smaller size of the rear tip extenders will facilitate their inser- tion into the narrow crura. Once the cylinders are in place, they should be inflated to check for adequate positioning and sizing. Filling of the devices can be done with 0.9% NaCl solution or with iso-osmolar dilute contrast agents. In Europe, contrast material is preferred, while in the United States surgeons prefer NaCl solution. The corporotomy incisions should be closed with 2-0 polydioxanone running suture. The input tubing of inflatable cylinders may be posi- tioned intracorporally and exit from the corpora at a convenient location or the tubing may exit directly where the tubing comes off the cylinder. If there is extensive scar tissue in the corpora, inflation and deflation of the cylinder may cause erosion of the cylinders where the tubing presses against the thick- ened tunica [25,56].

Placing the reservoir blindly into the retrovesical area from a scrotal incision requires special care. The superficial inguinal ring should be palpated and then elevated with a Deaver retractor. The index finger should be passed medial to the spermatic cord and should gently perforate the fascia transversalis, thus reaching the Retzius space. The use of an extra-long nasal speculum to open the space facilitates reservoir placement using a long clamp with no teeth. The reservoir should be filled adequately and the tubing connected using a specifically dedicated “quick” con- nector system. Blind placement of the reservoir should not be attempted when there is perivesical scarring, as may occur after cystectomy or prostatec-

142 Chapter 12 tomy. In such cases, the reservoir should be placed by

a second pararectal skin incision. Adequate filling of the reservoir can be achieved

with less than the maximum reservoir capacity of 50,

65 or 100 ml, but the filling volume should be at least

10 cm more than the maximum filling volume of both cylinders. The implant should then be activated and the wound closed, leaving the cylinders fully inflated. This improves hemostasis and reduces the risk of hematoma formation. The use of a drain is controversial. Some surgeons prefer to use a drain to reduce the risk of hematoma while other surgeons believe that an indwelling drain increases the risk of infection. The infrapubic approach has the advantage of implanting the reservoir under direct view. However, the infrapubic approach has the disadvan- tages of possible damage to the dorsal nerves of the penis with sensory loss, limited corporal exposure and lack of ability to fix the pump in the scrotum. If a urethral catheter is used, it should be removed on the first morning after surgery. The cylinders should be deflated to half their maximum volume on the first morning after surgery, when the patient usually is discharged from the hospital [14].

Anesthesia Penile implants may be placed under general or regional anesthesia. For the implantation of semi- rigid rod or soft silicone cylinders, a penile block with

a local anesthetic may be sufficient. After tourniquet

placement, about 25 cm 2 of 1% lidocaine are addi-

tionally instilled into each corpus cavernosum. Alternatively, surgery can be done with a pudendal block without the need of corpus cavernosum insti- lation [55]. For placement of hydraulic devices, penile blocks combined with pudendal blocks are preferred by some surgeons; most surgeons recom- mend general or spinal anesthesia [56].

Postoperative management Most patients are discharged on the first day after surgery and intravenous antibiotics are stopped at that time. At home, patients are usually prescribed one week of oral quinolones.

Patients are instructed to start activating and deac- tivating the implant as soon as the local pain has sub- sided enough to allow this. In most cases this takes

place during the first follow-up visit appointment seven to ten days after surgery. Sexual activity is not allowed until six weeks after the procedure, when the second outpatient visit should take place. Ideally, validated instruments, including the IIEF, should be used at three, six and/or 12 months after surgery to produce objective outcome data once the patient has resumed sexual activity on a regular basis. Particular care should be taken in assessing penile length and sensitivity, which represent two possible patient complaints [14].

Complications of penile prosthetic surgery and their management

Technical Considerations in Penile Prosthetic Surgery