Complications of penile prosthetic surgery and their management

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Intraoperative complications

The typical complication that may occur during dilation of the corpora cavernosa is perforation of the tunica albuginea. Typically the perforation occurs during the initial step of dilatation; if this is the case, interrupting the dilatation on that side and completing the same procedure contralaterally will show the real length of the crus. With a size nine Hegar dilator in place in the corpus cavernosum contralateral to the perforation, the surgeon should go back to the crus affected by the perforation and use only large dilators to complete the dilation. After completing the dilatation and placing the cylinders, a polydiox-ane suture may be passed through the rear tip of the cylinder and then through the tunica albuginea at the most proximal end of the corporotomy to anchor the cylinder in proper place. Alternatively a Dacron sock can be sutured to the rear tip of the prosthesis and fixed to the wall of the tunica with one or two sutures.

Proximal corporal perforations do not mean that surgery must be terminated. If there is a distal perforation, most experienced surgeons agree that surgery should be interrupted to prevent prosthesis infection. Although termination of surgery is the most prudent course in most distal perforations, in special cases such as extremely fibrotic corpora, primary suture of the albuginea with or without grafting may render good results. In such cases, after suturing the urethral perforation and inserting the cylinders, use of a suprapubic cystostomy tube or Foley catheter for one month has produced a successful outcome in a few reports [14].

Erectile Radiology
Fig. 12.3 Penile buckling due to overized left cylinder in MRI imaging.

Postoperative complications

The most significant postoperative complication associated with implant surgery is prosthetic infection, which occurs in 1 to 3% of cases [25]. Other important complications include distal and proximal perforation of the tunica albuginea, SST deformity, "S-shaped" deformity of the penis, erosion of a component, and mechanical malfunction of the device [30]. The best way to manage complications is to prevent them from happening by adequate sterile handling and correct sizing of the cylinders.

Diagnosis of complications is based on clinical history and physical examination, but imaging techniques may be useful to plan a surgical approach. MRI is the most valuable imaging technique for diagnosis of penile prosthesis complications [31]. MRI is radiation-free, demonstrates penile anatomy in three orthogonal planes, and is superior to any other imaging method in demonstrating soft tissue contrast [30,31,56] (see Figure 12.3). All penile implants except the now-discontinued Omniphase and Duraphase models, are compatible and safe with MRI field strength Tesla 1.5 and 3.0. The Omniphase or Duraphase prostheses are unsafe during MRI scanning due to their metallic components [60,61].

Prosthetic infection should be suspected when there is increasing postoperative pain, fever, ery thema of the incision or genitalia, and/or cutaneous fixation of prosthesis components, such as the pump to the scrotal skin [25]. This is the most feared complication after penile implant surgery. The use of antibiotics alone has not been successful in eradicating postoperative infections. It is difficult, if not impossible, for antibiotics to penetrate the area of a postoperative infection because the pseudo-capsule, which forms around the device, the relatively poor blood supply in the area, and the biofilm or slime produced by Staphylococci and other bacteria that provide a protected cavity in which bacteria can proliferate. When an infection develops around a portion of the implant, it may easily migrate to all other parts along the connecting tubes, as well as any foreign body, such as polytetrafluoro-ethylene or permanent sutures in the immediate area.

In the face of infection the surgeon has two options. The first is to remove the prosthesis and reinsert it at least three months or more later. If this option is chosen, the penis will be noticeably shorter and the reinsertion procedure more difficult because of the scar tissue that forms during that interval. The second option is to use a salvage procedure, which entails removing the prosthesis and all foreign materials, cleaning the wound with a series of antiseptic solutions and reinserting a new prosthesis at the same operation. Mulcahy [32] reported a success rate of 85% with the salvage procedure. There are several circumstances in which salvage should not be considered. These include prosthesis infections in patients with diabetic ketoacidosis, life-threatening sepsis, and frank tissue necrosis or urethral erosion of the cylinders in the fossa navicularis. If one excludes these conditions, a salvage approach is a reasonable procedure. According to a technique first described by Mulcahy [32,33], all prosthetic parts and foreign materials are removed; the wound is irrigated with a series of seven antibiotic solutions; the drapes, instruments, gloves and gowns are then changed, and a new prosthesis system placed in the wound.

Also a delayed form of salvage therapy using primary removal of the prosthesis, continuous antibiotic irrigation for several days, and secondary prosthesis reimplantation, ideally after 72 hours, has been published [25]. If salvage procedures are planned, it seems wise to treat the patient with systemic antibiotics for up to 48 hours prior to the salvage surgery, especially if fluid is available for culture and antibiotic testing [30].

If mechanical problems in an inflatable device develop after surgery, a trend to remove and replace the entire device has emerged recently. Common mechanical failures are tubing fracture, cylinder or reservoir leak, cylinder aneurysm, or connector disruption. Most urologists consider that replacing the entire device will give the patient added longevity in all parts [14,30]. Certainly after two or three years, it is prudent to replace all the prosthesis components because there can be significant wear of the device within that period. In addition, repeated penile incisions to change cylinders may shorten the penile length [34]. Furthermore, bacteria-positive cultures of clinically uninfected penile prostheses have been found in 70% of tested implants. In some patients, more than one organism grew, and in some patients the pump culture was negative but the biofilm was positive [35]. This may explain the higher infection rate that occurs with revision surgery [36,37,38]. Combining complete implant removal with a modified salvage protocol leads to a markedly decreased incidence of infection in patients with a penile prosthesis who are undergoing revision for non-infectious reasons [39].

A correct procedure in a properly selected patient does not necessarily result in a satisfactory outcome for the patient. A common reason for patient dissatisfaction is the lack of adequate engorgement of the glans during sexual activity. Typically, the patient reports that the corpora cavernosa are perfectly rigid after activating the implant but the glans remains soft, interfering with the patient's sexual satisfaction. Mulhall et al. [40] recently reported a beneficial effect of oral sildenafil on glans engorgement in patients with penile implants complaining of lack of glans engorgement. By using the IIEF, the authors also showed that sildenafil caused a statistically significant improvement in implant assisted intercourse. Similar results with the use of 500 |g of intra-urethral alprostadil were reported by Chew and Stuckey [41] in a patient who had been treated with a Dynaflex prosthesis.

In case of impending distal protrusion of cylinders, a new pocket for the tip of the cylinder within the distal corpus cavernosum should be created after hemicircumcision. Also windsock techniques with synthetic materials have been described for this condition. In some patients, an SST deformity develops, also termed "floppy glans". This condition is best treated by a circumcising incision, dissection of the glans from underlying tissue, and non-absorbable suture fixation of the glans to the tips of the corpora [56].

Re-operations

The reimplantation of an inflatable three-piece prosthesis in a patient with severe corporeal fibrosis is a surgical challenge. The worst fibrosis develops as a result of previous removal of an infected implant. Penile shortening results and dilatation of the scarred corporal bodies may be tedious and time-consuming. Wilson published an excellent review on special tools and techniques for these patients [28]. Correct cylinder sizing is of special importance in these cases. Sometimes it is prudent to implant a smaller device and exchange it for a larger device, after several months of active tissue expansion by regular and frequent use of the device. While the implantation of synthetic graft material is sometimes unavoidable, it is important to remember that the risk of infection during any penile prosthesis surgery correlates with duration of the procedure and amount of synthetic material that is implanted [56].

Results of penile prosthetic surgery

Generally penile implant surgery is associated with a high success rate [42]. In a recent study, the satisfaction rates of erectile function in patients treated with sildenafil, intracavernosal alprostadil injections, or three-piece inflatable penile prosthesis, were compared [43]. Patients enrolled in this study had failed initial sildenafil therapy. They were reinstructed on proper dosing and timing of sildenafil or directed to an alternative treatment. Satisfaction from treatment was assessed by a validated instrument, the Erectile Dysfunction Inventory for Treatment Satisfaction (EDITS), and erectile function was checked by the erectile function domain score of the IIEF. Total satisfaction and erectile function scores were significantly better in patients who had received the penile implant than in those treated with sildenafil or intracavernosal injection therapy. Mulhall et al. [44] assessed the effect of two- or three-piece inflatable implants in a series of men who used the IIEF and EDITS questionnaires at baseline and postoperatively. At one year follow-up, all assessments of erection, ejaculation, orgasm, and sexual satisfaction were significantly better than baseline values.

Several authors have reported their long-term results in studies published prior to 2000. In 1997, Daitch et al. [45] reported a five-year actuarial mechanical failure rate of 9.1% for AMS CX three-piece devices and 17.1% for Ultrex devices. This study suggested that mechanical failure is correlated with patient dissatisfaction, but this suggestion should be interpreted cautiously because some patients with surviving implants may also have little satisfaction. In 1999 Wilson et al. [46] reported the results of a prospective study of 1383 Mentor Alpha-1 penile implants and determined the mechanical survival of 410 original and 971 enhanced models. The five-year device survival rate increased from 75.3% for the original to 92.6% for the enhanced model overall, and from 75.3 to 93.6% for first-time implants only. The estimated failure rate was 5.6% for the original model and 1.3% for the enhanced model. Carson [47] reported a long-term multicenter study of the 700CX three-piece inflatable prosthesis, focusing on patients' satisfaction with a median follow-up of almost 48 months. At follow-up, 79% of the patients were using the implant at least twice monthly and 88% stated that they would recommend an implant to a friend with ED.

In a recently conducted multi-center study assessing the long-term reliability of three-piece AMS prostheses including the CX, CXR and Ultrex cylinders [48], at a mean follow up of 59 months, 92.5% of patients were still engaging in sexual intercourse with a mean frequency of 1.7 times weekly. Patients and partners reports of erection were excellent, satisfactory or poor in 48, 50, and 2%, and 17, 66, and 17%, respectively. Levine et al. [49] studied 112 patients who had an Ambicor two-piece prosthesis and 91 of their partners at a mean of four years after surgery. This study included a modified EDITS instrument, which showed that the procedure met the expectations of 87% of the patients, and that they were very confident with the device. A recent report of a head-to-head comparison of three-piece inflatable prostheses by Mentor and AMS did not reveal significant differences between the devices [50]. Data was collected by a computer-assisted telephone interview consisting of 37 questions. The overall satisfaction rate was 69% and 72%, and respondents reported that they would have the surgery performed again.

In another study, a psychosexual questionnaire was used to assess psychosexual benefits after implant surgery. Patients perceived an improvement in erectile ability and libido [51], and concerns about achieving and maintaining an erection during intercourse were significantly alleviated.

Montorsi etal. [14] reported an increase in the frequency of sexual activity, and improved satisfaction with sexual life in men with penile implants.

Only a few authors have reported long-term results of semi-rigid prostheses. Salama [52] reported that 70% of patients and 57% of partners were satisfied with their semi-rigid AMS 650 or Mentor Accu-Form prostheses. There was an increase in the frequency of intercourse, sexual desire and ability to achieve orgasm. Of note, dislike for the device was the most common cause for dissatisfaction among patients, while a sense of unnaturalness was the most common cause for dissatisfaction for partners.

In another recent study, Ferguson and Cespedes [53] reported five to seven year follow-up results with Dura-II penile prostheses. No mechanical defects were found in the 9% of men who had the device later explanted. Satisfactory rigidity was reported by 76% of the patients and ease of use was reported by 87%. A limitation of malleable implants is the potential for insufficient penile girth. Most of the patients having a semi-rigid penile implant have some form of penile vascular failure. Over time, spontaneous filling of the corporal tissue surrounding the cylinders tends to reduce. This may create the condition called "pencil-like erection", which is unsatisfactory to most patients [14].

Regardless of the type of prosthesis used, meticulous surgical technique and the surgeon's experience are the most important factors in determining the final outcome of the procedure. In addition, it is clear that the greatest chance for achieving satisfactory long-term results is at the time of the first implant. This underlines the importance of adhering to proven principles of patient selection, pre- and postoperative management and surgical technique, including meticulous observation of antiseptic procedures [54]. A recent paper has reported that the revision rate for penile prostheses may be much higher for inexperienced surgeons compared to experienced surgeons, and that inexperienced surgeons tend to select simple prosthetic devices, which may not fit the patients' expectations [59].

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Dealing With Erectile Dysfunction

Dealing With Erectile Dysfunction

Whether you call it erectile dysfunction, ED, impotence, or any number of slang terms, erection problems are something many men have to face during the course of their lifetimes.

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