Rigi10™ Malleable Penile Prosthesis
Also Known As
Cavernosal fibrosis, Penile fibrosis (when specifically referring to the corpora cavernosa), Corpus cavernosum fibrosis, CCF (Cavernous Cavernosum Fibrosis), Fibrosis of the corpora cavernosa, Corporal scarring
Definition
Corporal fibrosis is a pathological condition characterized by the excessive formation of fibrous connective tissue (scar tissue) within the corpora cavernosa of the penis.1 It involves the replacement of smooth muscle cells with fibrotic tissue inside the corpora cavernosa after an inciting event.2 This process leads to the overgrowth, hardening, and scarring of erectile tissues, primarily due to an excess deposition of collagen fibers and extracellular matrix components.3 The primary pathophysiological event is the over-expression of plasminogen activator inhibitor 1, transforming growth factor β1 (TGF-β1), and reactive oxygen species, which lead to increased myofibroblast activity and elevated collagen production and accumulation.4 This results in loss of corpora cavernosa sinusoid architecture, disorganized extracellular matrix, and scar contraction, ultimately impairing the tissue’s ability to expand and engorge with blood—a function essential for achieving and maintaining an erection.5 Consequently, corporal fibrosis is a significant contributor to erectile dysfunction (ED) and can lead to penile length loss and/or curvature.6
Clinical Context
Corporal fibrosis is clinically relevant in the context of erectile dysfunction (ED) and penile deformities. It is often encountered in patients with specific medical histories that serve as risk factors for developing this condition.1
The most common causes include:
- Priapism: Particularly refractory low-flow priapism, where prolonged erection leads to tissue hypoxia and subsequent fibrosis.2 The corporal fibrosis occurring secondary to ischemic priapism is typically more severe and dense distally.3
- Penile Trauma: Severe trauma to the penis can initiate a fibrotic healing process.4
- Penile Prosthesis Complications: Explantation of an infected penile prosthesis is a common precursor to significant corporal fibrosis.5 After removal of an infected penile prosthesis, the more severe and dense fibrosis is noted proximally.6
- Peyronie’s Disease: This condition is characterized by the formation of fibrous plaques in the tunica albuginea, but can also involve underlying cavernosal tissue.7
- Chronic Intracavernous Injections: Long-term use of vasoactive drugs injected directly into the penis for ED treatment can induce fibrosis.8 A study on 300 consecutive clinical cases who were long-term users of prostaglandin E1 (PGE1) showed that 23.3% of patients developed penile fibrosis.9
- Systemic Diseases: Conditions like diabetes mellitus and aging are associated with an increased risk of developing cavernosal fibrosis due to factors like oxidative stress and altered signaling pathways.10 Hypertension and castration have also been cited as etiological factors.11
Patient Selection Criteria: Patients presenting with ED, especially if it’s severe, progressive, or associated with penile pain, curvature, or shortening, should be evaluated for corporal fibrosis. Those with the risk factors mentioned above are particularly susceptible. Diagnosis may involve patient history, physical examination, and imaging studies like penile Doppler ultrasound or MRI to assess blood flow and tissue characteristics.12
Surgical Procedures: In cases of severe corporal fibrosis leading to ED unresponsive to conservative treatments, surgical intervention may be necessary. The primary surgical approach is often the implantation of a penile prosthesis. However, the presence of significant fibrosis makes this procedure more challenging, potentially requiring specialized techniques such as corporal excavation, scar tissue resection, and grafting to create adequate space for the implant and to restore penile length or correct deformities.13
Expected Outcomes: The expected outcome of treating corporal fibrosis depends on its severity and the chosen intervention. Conservative treatments in early or mild cases, such as phosphodiesterase-5 inhibitors (PDE5is) or pentoxifylline, aim to halt or reverse the fibrotic process and improve erectile function, though their efficacy in established, severe fibrosis is limited.14 For severe cases, penile prosthesis implantation can restore sexual function, but the presence of fibrosis can impact the complexity of the surgery, recovery, and final penile size.15 Fibrosis and loss of penile length after removal of an infected penile prosthesis can be significant, with the length of new cylinders potentially up to 7cm less than the length of the original prosthesis cylinders.16 This expected loss of length can negatively impact patient satisfaction.