bubble_chart Overview

Fibrous cavernositis of the penis is also known as penile induration. It was first reported by Peyronie in 1743, hence it is also called Peyronie's disease. The lesions are mainly confined to the white membrane of the penis and the space between the white membrane and the erectile tissue, characterized by localized fibrous patches. During erection, functional shortening and bending deformities may occur, and patients often suffer from psychological and sexual dysfunction.

bubble_chart Etiology

The cause of the disease is not well understood. In the 1960s, it was believed to be perivascular inflammation between the penile white membrane and the erectile tissue. However, anti-inflammatory treatments proved ineffective. Currently, it is thought that penile plaques are scars, not the result of inflammation, but rather an autoimmune process.

Various endogenous and exogenous factors that regulate collagen synthesis, such as ascorbic acid factor, 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 fibrous 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 penile white membrane is a layered structure, primarily stratified on the dorsal and lateral sides of the penis, with the outer layer composed of longitudinal fibers and the inner layer of circular fibers. On the ventral midline, the outer fibers of the penile white membrane are sparse, forming a single layer. The septal fibers fan out and intertwine with the inner layer fibers of the white membrane to form a ring-like structure.

When the white membrane sheath and septal fibers are stretched to their maximum extent, the septum forms an I-shape, and the hydrostatic pressure within the corpora cavernosa generates stress. Excessive external tension (dorsiflexion or ventriflexion) can disrupt this balance mechanism, leading to the separation between the inner and outer layers of the white membrane and the formation of a potential cavity. Blood extravasation into this cavity triggers an inflammatory reaction, 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 white membrane, patients prone to scar formation may find fibrinogen difficult to clear during the remodeling phase, leading to fibrosis. However, in most cases of penile trauma, the inflammatory reaction and induration in the white membrane and surrounding tissues can fully recover without fibrosis.

Trauma to the penile white membrane can be caused by sexual intercourse, instrumental examinations, or direct injury. Some patients develop fibrous 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 white membrane in young people, while in the elderly, it is associated with reduced intense sexual activity. In middle-aged individuals, the elasticity of the white membrane decreases, and if combined with intense and frequent sexual activity, it can easily lead to the occurrence of fibrous cavernositis of the penis.

bubble_chart Clinical Manifestations

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. 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 harden, and the penile curvature becomes irreversible.

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, plantar fascia scarring in Ledderhose disease, and 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 predisposition has been observed, no correlation has been found with HLA-B7 or HLA-B27.

The condition predominantly affects middle-aged individuals, typically 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 usually does not progress further.

Penile curvature and deformity can lead to sexual dysfunction. If erectile dysfunction is present, it may indicate psychological distress or organic vascular sexually transmitted diseases.

Palpable nodules or cord-like plaques of varying sizes, single or multiple, can be felt on the dorsal aspect of the penis, with no or mild tenderness. Pain may occur during erection. The condition does not involve the urethra, causing no urinary or ejaculatory dysfunction. If plaques calcify or ossify, plain X-rays can reveal the lesions and measure their size.

The disease should be differentiated from congenital penile curvature, dorsal penile vein thrombosis, post-traumatic penile fibrosis, and leukocyte infiltration of the corpora cavernosa.

bubble_chart Auxiliary Examination

High-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 white membrane of the corpus cavernosum, the stirred pulse of the corpus cavernosum, and venous function. It can also observe the collateral stirred pulse between the dorsal stirred pulse of the penis and the corpus cavernosum, as well as between the corpus cavernosum and the corpus cavernosum stirred pulse. In some cases, when examining the penile blood vessels, if a branch of this vessel is injured, erectile dysfunction may occur.

Cavernous perfusion dynamics measurement and cavernosography. After intracavernosal injection of vasoactive agents, physiological saline is perfused to measure the speed of venous overflow fistula disease. Diluted contrast agent is injected into the corpus cavernosum, and X-ray plain films are taken to observe the site of venous blood fistula disease. It has been reported that approximately 36% of patients with erectile dysfunction combined with penile fibrotic cavernositis have abnormal penile stirred pulse blood flow, while 59% have abnormal venous closure function. This indicates that an important cause of erectile dysfunction in patients with penile fibrotic cavernositis is the presence of penile vascular insufficiency.

bubble_chart Treatment Measures

The outcome of penile fibrotic cavernositis is approximately 13% remission, 47% no change, and 40% gradual progression. Although cases of complete resolution without treatment have been reported, they are extremely rare. Even if the lesions resolve spontaneously, it usually takes several years.

Young patients with soft patches smaller than 2 cm and a short duration of symptoms have a better prognosis. If the penis forms an angle greater than 45° early on, the deformed penis is less likely to return to normal. Calcification of the patch indicates a poor prognosis.

Sufficient time should be allowed to observe the progression of the lesions, and treatment plans should be decided only after the condition stabilizes.

For patients with patch lesions that do not affect erection or sexual intercourse, drug therapy is generally recommended. Vitamin E (400 mg, twice daily) is a free radical scavenger that promotes connective tissue repair with no significant side effects. Other drugs with clinical reports include 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. However, some of these drugs have severe side effects and should be used with caution. Intralesional injections are also advocated, commonly using parathyroid hormone, dimethyl sulfoxide, cortisone, collagenase, superoxide dismutase, interferon, or verapamil. Most reported cases are non-randomized, lack placebo controls, or are not large-scale summaries, making it difficult to evaluate the true efficacy of these drugs. Comprehensive literature reports indicate that the effectiveness of drug therapy is almost always less than 50%. Additionally, there are reports on the use of X-rays, ultrasound, iontophoresis, and laser therapy, 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 piece 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 simple and has fewer complications. Both methods do not injure the corpora cavernosa and generally do not affect erectile function postoperatively, with satisfactory outcomes, making them widely used in clinical practice. Gelbard and Hayden (1991) suggested not removing the tunica albuginea but making several relaxing transverse incisions on the concave side of the curved penis and filling the incisions with grafts. Others advocate removing the penile patch and repairing the local defect with grafts, such as dermis, great saphenous vein, tunica vaginalis, or synthetic materials. However, since the lesions often extend beyond the patch and infiltrate surrounding erectile tissues, excessive removal of the patch and surrounding tissues may risk erectile dysfunction. Montorsi et al. (1994) emphasized the use of color Doppler ultrasound preoperatively to assess penile hemodynamic parameters and accurately evaluate the structure of the corpora cavernosa and venous function. If penile venous insufficiency is present, patch removal and defect repair are not recommended, as the postoperative erectile dysfunction rate can be as high as 70%.

For penile curvature combined with erectile dysfunction, the curvature should be corrected first, followed by minimally invasive treatments for erectile dysfunction, such as intracavernosal injection of vasoactive drugs, intraurethral administration of Muse, or vacuum erection devices, which may achieve therapeutic effects. If non-surgical therapy fails, penile prosthesis implantation may be considered.