| disease | Peyronie's Disease |
Fibrous cavernositis of the penis is also known as penile induration. It was first reported by Peyronie in 1743, hence also called Peyronie's disease. The lesions are mainly confined to the tunica albuginea of the penis and the space between the tunica albuginea and the erectile tissue, characterized by localized fibrous patches. During erection, functional shortening and bending deformities may occur, often accompanied by psychological and sexual dysfunction in patients.
bubble_chart Etiology
The cause of the disease is not well understood. In the 1960s, it was believed to be perivascular inflammation between the white membrane of the penis and the erectile tissue. However, anti-inflammatory treatments were ineffective. Currently, it is thought that penile patches are scars, not inflammation, and are the result of an autoimmune process.
Various endogenous and exogenous factors that regulate collagen synthesis, such as ascorbic acid, EGF, IGF, etc., play an important role in the pathogenesis of penile fibrotic cavernositis. TGF-β, as a cytokine affecting extracellular matrix deposition, can induce fibrosis of the penile white membrane.
bubble_chart Pathological Changes
The view that trauma contributes to the onset of fibrotic cavernositis of the penis has been widely accepted. Clinical and pathological examinations reveal that all patches are located on the dorsal or ventral midline of the penis and are attached to the septal fibers. The tunica albuginea of the penis is a layered structure, primarily stratified on the dorsal and lateral sides of the penis, with the outer layer consisting of longitudinal fibers and the inner layer of circular fibers. On the ventral midline, the outer fibers of the tunica albuginea are sparse, forming a single layer. The septal fibers fan out and interweave with the inner layer fibers of the tunica albuginea to form a ring-like structure.
When the tunica albuginea sheath and septal fibers are stretched to their maximum extent, the septum forms an I-shape; the stress is exerted by the hydrostatic pressure formed within the corpora cavernosa. Excessive external tension (dorsiflexion or ventroflexion) can disrupt this balancing mechanism, leading to the separation between the inner and outer layers of the tunica albuginea and the formation of a potential cavity. Blood extravasation into the cavity triggers an inflammatory response, resulting in induration. After the dissolution of the blood clot in the potential cavity, fibrinogen remains in the space. Retained fibrinogen can activate fibroblasts, increase vascular permeability, and produce inflammatory factors. Although this is a normal healing response, due to the lack of vascular distribution in the tunica albuginea, patients prone to scar formation may not easily clear fibrinogen during the remodeling phase, leading to fibrosis. However, in most cases of penile trauma, the inflammatory response and induration in the tunica albuginea and surrounding tissues can fully recover without fibrosis.Trauma to the tunica albuginea of the penis can result from sexual intercourse, instrumental examinations, or direct injury. Some patients may develop fibrotic cavernositis of the penis without any history of trauma or even sexual activity. This condition is more common in middle-aged individuals and rare in young and elderly people. This is related to the high elasticity and strong resistance to flexion and extension of the tunica albuginea in young people, while in the elderly, it is associated with reduced intense sexual activity. In middle-aged individuals, the elasticity of the tunica albuginea declines, and if combined with intense and frequent sexual activity, it can easily lead to the occurrence of fibrotic cavernositis of the penis.
bubble_chart Auxiliary ExaminationHigh-resolution superficial color Doppler ultrasound can objectively determine the size of patches or calcifications, the number of lesions, and evaluate treatment efficacy.
Before and after intracavernosal injection of vasoactive agents, color Doppler ultrasound can be used to examine the tunica albuginea of the corpus cavernosum, the cavernosal artery pulsation, and venous function. It can also observe the collateral pulsation between the dorsal penile artery and the corpus cavernosum, as well as between the corpora cavernosa. In some cases, when examining penile blood vessels, if a branch of these vessels is injured, erectile dysfunction may occur.
Cavernosal perfusion dynamics and cavernosography. After intracavernosal injection of vasoactive agents, physiological saline is perfused to measure the rate of venous leakage. Diluted contrast agent is injected into the corpus cavernosum, and X-ray plain films are taken to observe the sites of venous leakage. It has been reported that approximately 36% of patients with erectile dysfunction combined with penile fibrotic cavernositis exhibit abnormal penile artery blood flow, while 59% have abnormal venous occlusion function. This indicates that an important cause of erectile dysfunction in patients with penile fibrotic cavernositis is the presence of penile vascular insufficiency.
Peyronie's disease can be divided into acute and chronic phases. The acute phase is characterized by acute inflammatory reactions and pain, primarily occurring during penile erection, with 30-40% of patients experiencing significant pain symptoms. This phase can last for several months, during which nodules may form on the penis, causing progressive curvature toward the affected side. When active inflammation of the penile tunica albuginea ceases, the condition enters the chronic phase. During this phase, pain symptoms typically disappear, fibrous plaques become hardened, and the curved penis cannot straighten.
Peyronie's disease is also considered a fibrotic tumor-like condition of the penis. Similar fibrotic processes occur in other important tissues of the body, such as the palmar fascia scarring in Dupuytren's contracture, the plantar fascia scarring in Ledderhose disease, and the tympanic membrane scarring in tympanosclerosis. Approximately 30% of Peyronie's disease cases are associated with Dupuytren's contracture, while only 3% of Dupuytren's contracture cases involve Peyronie's disease. Although a familial tendency has been observed, no correlation has been found between the disease and HLA-B7 or HLA-B27.The condition predominantly affects middle-aged individuals, primarily between 45 and 60 years old.
Most cases of Peyronie's disease develop insidiously, with patients experiencing unsatisfactory erectile function, painful plaques, and slowly progressive penile curvature. Some cases present abruptly, with sudden penile curvature that typically does not progress further.
Penile curvature and deformity can lead to sexual dysfunction. If erectile dysfunction is present, it may indicate psychological barriers or organic vascular sexually transmitted diseases.
Hard nodules or cord-like plaques can be palpated on the dorsal side of the penis, varying in size, single or multiple, with no or mild tenderness, and may cause pain during erection. The condition does not affect the urethra, causing no urinary or ejaculatory dysfunction. If plaques calcify or ossify, plain X-rays can reveal the lesions and measure their size.
bubble_chart Treatment Measures
The outcome of penile fibrotic cavernositis shows that approximately 13% of cases may resolve, 47% remain unchanged, and 40% gradually progress. Although there have been reports of untreated cases where the lesions completely disappeared, such instances are exceedingly rare. Even if the lesions resolve spontaneously, it typically takes several years.
Young patients with soft plaques smaller than 2 cm and a short symptomatic duration have a better prognosis. If the penis develops an angle greater than 45° in the early stages, the deformed penis is unlikely to return to normal. Calcification of the plaque indicates a poor prognosis.
Sufficient time should be allowed to observe the progression of the lesion, and treatment options should be decided only after the condition stabilizes.
For patients with plaque lesions that do not affect erection or sexual intercourse, medical treatment is generally recommended. Vitamin E (400 mg, twice daily) acts as a free radical scavenger, promoting connective tissue repair with no significant side effects. Other medications such as para-aminobenzoic acid (PABA, which may be tried in young patients with painful erections as the main symptom), mefenamine (Allerga), colchicine, tamoxifen, steroids, and procarbazine have also been reported in clinical studies. However, some of these drugs have severe side effects and should be used with caution. Intralesional injections, such as parathyroid hormone, dimethyl sulfoxide, cortisone, collagenase, superoxide dismutase, interferon, and verapamil, have also been proposed. Most reported cases involve non-randomized selections, lack placebo controls, or are not based on large-scale case summaries, making it difficult to assess the true efficacy of these drugs. Comprehensive literature reviews indicate that the effectiveness of drug therapy is almost always less than 50%. Additionally, treatments such as X-ray therapy, ultrasound, iontophoresis, and laser therapy have been reported, but their efficacy remains uncertain.
The goal of surgical treatment is to correct penile curvature and restore sexual function. The method advocated by Nesbit involves removing a small elliptical portion of the tunica albuginea on the convex side of the curvature, then suturing the incised tunica albuginea to close the defect and straighten the penis. If the penile length is sufficient and the curvature is grade I, without incising the tunica albuginea, simple suturing of the longer side of the tunica albuginea may suffice. This method is straightforward and has fewer complications. Both approaches do not injure the corpora cavernosa and generally do not affect erectile function postoperatively, yielding satisfactory results, which is why they are widely used in clinical practice. Gelbard and Hayden (1991) suggested avoiding tunica albuginea resection and instead making several relaxing transverse incisions on the concave side of the curved penis, filling the incisions with grafts. Others advocate removing the penile plaque and repairing the defect with grafts, such as dermis, saphenous vein, tunica vaginalis, or synthetic materials. However, since the lesion often extends beyond the plaque and infiltrates surrounding erectile tissue, excessive removal of the plaque and surrounding tissue raises concerns about erectile dysfunction. Montorsi et al. (1994) emphasized the importance of preoperative color Doppler ultrasound to assess penile hemodynamic parameters and accurately evaluate the structure of the corpora cavernosa and venous function. If penile venous insufficiency is present, plaque resection and defect repair are not recommended, as the postoperative erectile dysfunction rate can be as high as 70%.
For cases of penile curvature combined with erectile dysfunction, the curvature should be corrected first, followed by minimally invasive treatments for erectile dysfunction, such as intracavernosal injections of vasoactive drugs, intraurethral administration of Muse, or vacuum erection devices. These methods may achieve therapeutic effects for erectile dysfunction. If non-surgical therapies fail, penile prosthesis implantation may be considered.
This disease should be differentiated from congenital penile curvature deformity, dorsal penile stirred pulse embolism, post-traumatic penile fibrosis, and leukocyte infiltration of the corpora cavernosa.