Malleable Penile Prosthesis

A malleable penile prosthesis is clinically indicated for adult males with erectile dysfunction (ED) who have not responded to, are not candidates for, or are dissatisfied with less invasive treatments such as oral medications (e.g., PDE5 inhibitors), intracavernosal injections, or vacuum erection devices.¹ It is considered a third-line therapy for ED.⁶ Malleable implants may be particularly suitable for patients with limited manual dexterity or cognitive impairment who might find the operation of an inflatable prosthesis challenging, or for those who prefer a simpler, permanently firm device.² Other indications can include ED secondary to conditions like Peyronie\’s disease (with or without plaque incision/excision and grafting), priapism leading to corporal fibrosis, or following radical pelvic surgeries (e.g., prostatectomy, cystectomy) that result in intractable ED.⁷

Patient selection criteria involve a thorough medical history, physical examination, and discussion of patient/partner expectations and lifestyle.²¹ Key considerations include the patient\’s overall health, surgical fitness, motivation, and understanding of the potential outcomes, risks, and limitations of the prosthesis.¹&sup8; Patients with active infections (systemic or localized to the urinary tract/genitalia), unresolved voiding dysfunction, or unwillingness to undergo potential revision surgery are generally not candidates.¹ Contraindications also include severe psychological conditions that might impair the ability to cope with an implant, or unrealistic expectations regarding penile size or function.²²

The surgical procedure typically involves making an incision (e.g., penoscrotal, infrapubic) to access the corpora cavernosa (the erectile chambers of the penis). The corpora are then dilated to create space for the two prosthetic cylinders. The malleable rods are sized appropriately and inserted into each corpus cavernosum.¹ The penis remains semi-rigid, allowing it to be manually positioned for intercourse or bent downwards for concealment. The procedure is usually performed under general or spinal anesthesia.²&sup5;

Expected outcomes include the ability to achieve a penile erection firm enough for sexual intercourse, thereby restoring sexual function for many patients.&sup5; Patient satisfaction rates with malleable prostheses are generally good, although they may be slightly lower than with three-piece inflatable devices in some studies, often due to the permanent semi-rigidity.² However, malleable implants have a lower risk of mechanical failure compared to inflatable devices.² Potential complications include infection (the most serious risk), erosion of the device through the skin, pain, mechanical malfunction (though less common than inflatables), and potential for penile shortening or altered sensation.¹³ Thorough preoperative counseling is crucial to set realistic expectations regarding penile length, girth, and the nature of the erection achieved with a malleable prosthesis.²¹