What Is A Penile Implant?

Introduction

Penile implants are an effective treatment for erectile dysfunction (ED). Penile implants were introduced in the early 1970s as a means of reliable treatment for all types of ED. Patients suffering from ED have benefitted tremendously since its introduction. 

In the past, patients suffered silently and ED was often incorrectly classified as psychogenic in origin. Early implants often had mechanical troubles and required frequent maintenance and repair. This further exacerbated the stigma around ED, fortunately, implants continued to be developed that could be more reliable and effective in managing ED.¹

Types of penile implants

Over time, the development of penile implants lead to better mechanical reliability and safety. There are two types of commonly used penile implants: 2-piece and 3-piece inflatable penile prosthesis (IPP), and semi-rigid penile prosthesis (SPP).² Both of these implants consist of a pair of cylinders inserted into the corpora cavernosa, while IPPs have additional components such as a pump and/or reservoir.³

IPPs were first established in 1973 but were unreliable, with patients experiencing mechanical failure rates ranging from 21-45% during the first year of implantation. This has been curbed over the years with the advancement of different types of IPP in the market.² 

The 3-piece IPP exhibits similar functionality during both the erect and flaccid state. This implant comprises a pair of cylinders, a pump, and a reservoir of salt water which are embedded in the penile corporal bodies, the scrotum, and the abdominal wall respectively. The saltwater is pumped from the reservoir into the cylinders, allowing the patient to regulate penile rigidity and flaccidity. Similarly, the 2-piece IPP consists of a pair of cylinders, but the pump and reservoir are combined as a single unit. The 2-piece has been beneficial for patients who have already undergone multiple abdominal surgeries. 

SPPs, on the other hand, are penile implants consisting of two poly-ether-ketone flexible rods implanted into the penis. They regulate stiffness and size and result in a permeant semi-rigid state. Comparatively, SPPs have a lower risk for dysfunction.^4,5

Indications for penile implants

Penile implants are the gold standard of treatment for ED. In 1998, the systemic combination therapy of sildenafil citrate became the first line of oral medication therapy for ED. However, the success rate of this therapy was limited and second-line treatments such as sex therapy, vacuum device therapy, intraurethral medications, and penile injection therapy were often considered.⁶ 

Apart from ED, penile implants were also commonly used for other medical conditions, namely Peyronie’s disease, ED post-prostatectomy, and severe cases of vascular disease. 

Peyronie’s disease is a condition where fibrous scar tissue forms in the deeper tissues under the skin of the penis which results in curved and painful erections. Penile prosthesis implantation is a safe and reliable technique for straightening penile curvature.⁷ 

Patients undergoing a prostatectomy may experience ED post-surgery due to artery and nerve damage. Penile prosthesis implantation can allow the preservation of erectile function after a prostatectomy.⁸

Evaluation and candidacy

Similar to every surgery, patients undergo a crucial medical assessment and diagnostic procedures for penile implantation. Past medical and surgical histories are important elements for any diagnostics. Some patients may have other health implications when seeking treatment for ED which could affect the success of prosthetic surgery. These health implications range from vascular disease to diabetes and prior medical assessment is vital before surgical intervention.⁹

Based on the preoperative determination protocol, some patients may be assessed to have psychological conditions that are unsuitable for prosthesis implantation, which prompts the need to administer psychological analysis before surgery. 

Some patients may experience dissatisfaction with an implant due to a variety of reasons, such as: 

• Reduction in penile size 
• Expectations not met 
• Difficulty participating in sexual intercourse
• Artificial or unnatural appearance 
• Difficulty ejaculating 
• Malfunction

Studies have shown the importance of psychological evaluation and clearly defined expectations before penile implantation surgery to maximise patient satisfaction. Additionally, the best candidates for implantation are those who have already tried more conservative treatments and require a more reliable source of treatment for their ED.¹⁰ 

Surgical procedure

A week before the operation, the patient undergoes several medical tests to determine fitness for the surgery. These include presurgical urine and blood tests along with medical and cardiac clearances.¹¹ 

During the surgery, general anaesthesia is administered and the patient is prepped from the belly button down to the mid-thigh. 3-piece IPP implantation is performed by making either an infrapubic (lower abdomen) or penoscrotal (underneath the penis) incision. This decision is based on the surgeon’s preference and patient anatomy. 

A skin incision is performed and subcutaneous tissue is dissected down the penile shaft on each side of the urethra. Once all the components are connected and in position, the incision is closed in two layers. 

There have been several complications observed with this surgery. Infection is the most worrisome complication of the surgery followed by acute fever. Another common complication is the potential for deformity and potential ‘floppy glans syndrome’ (hypermobility of the penis, even when erect) due to improper cylinder size. This can consequently lead to an undesired cosmetic appearance and cause difficulty performing intercourse.¹²   

Postoperative care and recovery

Postoperative care and recovery is crucial. A catheter may be required while recovering in the hospital. Patients are advised not to sit on the scrotum for the first three postoperative days. They are also instructed to keep the penis straight and up, towards the belly button until inflation of the penile shaft. Patients should be able to perform daily tasks once no discomfort is observed in the shaft of the penis. They can resume sexual activity four weeks post-surgery, provided that they attend at least two postoperative check-ins with their physician.¹³

Benefits and risks

Penile implants have posed many positive outcomes and improvements in the quality of lives of patients. Since the implant is completely encased within your body it is virtually invisible. It is convenient and easy to achieve erection for ED patients. Thanks to advancements in implant technology, implants now have long-term durability and a minimal recovery time is required.¹⁴ 

However, it must be noted that surgery complications can occur, impacting a patient’s quality of life and overall satisfaction with the implant. Complications such as infection, prosthesis malfunction, penile corporal perforation, and penile length loss are possible outcomes to consider. 

Several factors can be considered to reduce the risk of surgical complications, such as appropriate patient selection, methodical preoperative assessment, and following specific intraoperative protocols and postoperative recommendations. 

Patient experience and satisfaction

In the past, there have been high rates of patient dissatisfaction associated with penile implantation and as few as 50% of patients reported tumescence during sexual arousal. The reoperation rate was also significantly high and patients were not fully satisfied with their sexual relationship despite achieving a functional erection. 

This prompted the need for sexological counselling pre and post-operation.¹⁵ Recently, patient satisfaction has improved due to the involvement of psychological counselling. A study conducted on 52 people assigned male at birth (AMAB) showed that all, except 4 patients, had sexual intercourse regularly suggesting an improved sexual relationship. Furthermore, only a quarter of the patients reported restriction in intercourse positions.¹⁶

Cost and insurance considerations

The financial aspect of penile implants is debated as most insurance companies do not cover penile implant costs. Patients tend to self-finance their surgery and counselling sessions. The average cost of consultation is estimated to be £700, whereas the surgical treatment costs range from £1500 to £15000 depending on the device implanted. 

Future trends and advances

Recent decades have seen advancements in penile prosthesis design and technique. These include enhancements in reservoir design, cylinder characteristics, and the widespread use of infection retardant coatings which have become reliable and accessible to patients. 

Future research warrants investigation into other factors such as surgical approach, patient age, geography, implant size, and the cause of ED to improve the functionality of penile implants.¹⁷

Summary

Penile implants are a viable treatment option when conservative treatment fails but patients do need to consider the risks and consequences that can arise with surgery. However, penile implants can pose many beneficial impacts on a patient’s quality of life. Therefore, it is vital to have open communication between patients and physicians to maximise patient satisfaction.