Penile curvature surgeries
The indications for surgical reconstruction include men with stable disease for at least 6 months who have a painless deformity. It would also be expected that the surgery would not be performed before one year after onset of disease. The patient should also have a compromised or inability to engage in coital activity due to deformity and/or inadequate rigidity. The patient with extensive plaque calcification may also be a good candidate for surgery, and certainly those who want the most rapid and reliable result are best treated with surgical correction. The preoperative consent is critical in this patient population, as these men are oftentimes unhappy with their deformity and in fact, up to 40% have been shown to have evidence of clinical depression. Therefore, setting appropriate expectations regarding outcomes before surgery is critical to ensure that the patient understands the limitations and possible side effects of surgery. These side-effects include a persistent or recurrent curvature. The goal of surgery is to make the patient “functionally straight,” which has been loosely defined as less than 20 degrees of curvature in any direction, which should not interfere with penetrative sex. There could be shortening of the penis, more commonly noted with plication than grafting procedures, as well as diminished rigidity (ED), which has been reported in all surgical studies, especially with the grafting operations, but appears to be most dependent upon preoperative erectile status. Lastly there could be diminished sexual sensation. This tends to be common in the early postoperative period but usually resolves.
Three surgical algorithms have been published since 1997 and have essentially agreed that there are two important factors determining the surgical approach. The first is that the patient can develop adequate penile rigidity for coitus with or without drug assistance, and the second is the degree of deformity. In those men who have adequate preoperative rigidity and a simple curvature of 60-70 degrees or less with no hinge effect or hourglass deformity, then a tunica plication technique can be used. For those who have a more severe or complex curvature or a destabilizing hourglass narrowing, then plaque incision or partial excision and grafting is recommended. Several surgical plication techniques have been developed since the 1960’s, including the Nesbit procedure, which is performed by cutting out a wedge of tunic on the convex (longer aspect of the penis) with closure of that defect to straighten the penis. There are a variety of plication operations, where incisions or sutures are placed to shorten the longer side of the penis without excising the tunic. There is no evidence that one particular procedure is superior to the other. The most important factor here appears to be physician preference and expertise with a particular approach. Overall, the plication operations have been shown to allow “functional straightness” in 85-100% of patients with up to 13% experiencing new ED.
Incision or partial excision and grafting is indicated for those who have strong erections preoperatively, curvature greater than 60-70 degrees and significant shaft narrowing, especially when there is a hinge effect. The goal of the operation is to limit trauma to the underlying cavernosal tissue so as to maintain the venous trapping relationship between the tunic and the graft with the underlying penile vascular (cavernosal) tissue. A variety of surgical grafting approaches have been used, including using grafts such as dermis, vein, tunica vaginalis, buccal mucosa, and postauricular skin, as well as allografts and xenografts, including processed, human and bovine pericardium, porcine subintestinal submucosa, and pig dermis. No graft has been found at this time to be the ideal graft, which would always have complete take, not contract, have adequate strength, resist infection, and reduce the risk of postoperative erectile dysfunction. Overall it appears that procedures with autologous grafts require more time and a second incision, whereas processed, off-the-shelf allograft and xenograft procedures appear shorter in duration with no reported transmission of disease. Synthetic grafts such as PTFE (Gore-Tex) and Dacron, increase the risk of infection and are palpable and therefore, not recommended. The primary concern is that there is an increased risk of postoperative erectile dysfunction with grafting procedures. In review of the literature, it appears that satisfactory straightening occurs with grafting in 74-100% of patients, with a range of new ED following surgery in 5-53%. Recent studies performed by centers of excellence show new ED rates in the 5-30% range.
In addition, recent studies have examined preoperative factors to determine if there are predictors of developing post-operative erectile dysfunction. A recent presentation examining all vascular risk factors, as well as: patient age, severity and direction of deformity, graft size, and pre-operative penile duplex ultrasound parameters demonstrated no statistically significant predictor for post-operative ED. It therefore appears that the most critical factors will be the patient’s preoperative erectile status and the experience of the surgeon.
In those patients with inadequate rigidity, placement of a penile prosthesis is recommended. Occasionally just placement of a prosthesis alone will provide adequate straightening, but in those patients with more severe deformity, a stepwise approach is taken to straighten the penis. It should be noted that a prosthesis that provides good axial rigidity is more likely to result in straightening than those which can expand in girth and length. In addition, malleable prostheses do not appear to provide good axial rigidity resulting in suboptimal straightening postoperatively. When penile prosthesis placement alone does not provide enough straightening, manual modeling as described by Wilson in 1994 appears to result in satisfactory straightening in the great majority of patients. This must be done with care to reduce the likelihood of urethral trauma. When there is inadequate straightening following manual modeling, Buck’s fascia can be mobilized followed by an incision of the scarred tunic. If the incision leaves a substantial tunic defect, which might result in prosthesis herniation, then grafting of the defect is recommended.
A recent presentation (Nov. 2009) examined 89 patients undergoing placement of a penile prosthesis for Peyronie’s disease with drug refractory erectile dysfunction. The study had up to a 9 year follow-up, and revealed a low prosthesis mechanical failure rate of approximately 4%, and an overall high patient satisfaction rate of 85%.
In summary, with respect to surgery, a detailed pre-operative consent is imperative to set appropriate patient expectations. A plication procedure is recommended for mild to moderate deformities (less than 60 degrees), and when there is borderline erectile dysfunction. Grafting is reserved for severe deformity greater than 60-70 degrees, and/or when there is a hinge effect. Most importantly these procedures should be offered when there is good pre-operative erectile function and when the procedure is being performed by an experienced surgical team. Prosthesis placement with additional maneuvers is recommended when the patient has erectile dysfunction that fails to respond to medical therapy.