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F. E. Martins et al. (eds.)Textbook of Male Genitourethral Reconstructionhttps://doi.org/10.1007/978-3-030-21447-0_44

44. Penile Prosthesis Implantation: Penoscrotal Approach

Hussain M. Alnajjar¹ and David J. Ralph¹

(1)

The Institute of Andrology, Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK

David J. Ralph

Email: dralph@andrology.co.uk

Keywords

Erectile dysfunctionPenile prosthesisPenoscrotal

44.1 Introduction

Patients with erectile dysfunction (ED) are often initially managed with lifestyle changes, oral pharmacotherapy and Vacuum Erection Device (VED). If these measures fail, patients maybe commenced on intracavernosal injections or intraurethral medications consisting of Alprostadil. Examples of intracavernosal and intraurethral medications are Caverject® and MUSE® respectively.

In the event that none of the above conservative measures or treatments work, implantation of penile prosthesis may be considered. The term “end-stage” or “refractory” ED is used in patients who have exhausted all medical treatments. However, penile prosthesis may be inserted in the absence of end-stage ED, due to other reasons , such as patient choice (dissatisfaction with or contraindication to oral or intracavernosal pharmacotherapy use), Table 44.1.

Table 44.1

Indications for penile prosthesis insertion

Indications and Patient Selection
Refractory erectile dysfunction
Failure to tolerate pharmacotherapy/patient choice
Refractory ischaemic priapism
Buried penis
Difficulty with using condom sheath for incontinence
Neurological conditions/spinal injury

44.2 Patient Selection and Counselling

Patients undergoing penile prosthesis surgery require a detailed pre-operative assessment and counselling prior to their operation (Fig. 44.1). This is a crucial step to ensure that patients have made fully informed decisions and that they understand what the surgery entails and its intended objectives. Patients should also be provided with adequate training and information beforehand. It is highly recommended that patients should be provided a demonstration of the various devices allowing them to understand how the devices operate, familiarize themselves with the pump and how to cycle the device. This will also allow them to appreciate the feel and texture of the various components of the device. It is crucial to provide patients with written information concerning the surgery, options of prostheses, advantages versus disadvantages, and potential risks associated with the operation (Table 44.2). Patients should be given sufficient time to come to a decision prior to proceeding with surgery. It is also important to involve their partner, if possible.

Fig. 44.1

Penile prosthesis counselling proforma (Courtesy of Clare Akers and Fiona Holden)

Table 44.2

Consent proforma , potential risks associated with penile prosthesis insertion

Infection

Bleeding

Soft glans/Super-Sonic Tilt (SST)

It will not increase penile length

Mechanical failure

Urethra, bladder, bowel injury

Glans hypoaesthesia

Erosion

During patient counselling, particular considerations should be given to patient’s medical and surgical history when considering the type of penile prosthesis. A summary of specific considerations to patient factors when choosing the most suitable penile prosthesis is listed in Tables 44.3 and 44.4.

Table 44.3

Patient factors to be considered before choosing the most suitable penile prosthesis

Diabetes mellitus

Spinal cord injury

Manual dexterity

Previous pelvic surgery

Previous radiotherapy

Presence of Artificial Urinary Sphincter (AUS)

Immunosuppression

Penile conditions e.g. Peyronie’s disease, acute or chronic priapism, phimosis

Stretched penile length

Body habitus

Abdominal scars/presence of stoma

Scrotal size

Patient’s preference

Table 44.4

Absolute indications for penoscrotal approach

Absolute indications for penoscrotal approach
Peyronie’s disease
Corporal fibrosis
Obesity
Presence of artificial urinary sphincter
Phalloplasty

44.3 Penile Prosthesis Types and Options

The current and most commonly used inflatable penile prostheses are from two companies, Coloplast Coroporation (Denmark) and Boston Scientific (USA).

Coloplast currently markets Titan® Touch, a self-contained three-piece fluid filled system with an incorporated hydrophilic coating on all components. It is made from the durable Bioflex® and silicone materials. The coating allows for soaking of the device in an antibiotic solution according to the surgeons’ preferred choice of antibiotics prior to implantation to reduce infection risk and aid in surgical placement. The Titan IPP products are available in a variety of lengths ranging from 11 cm to 28 cm.

Coloplast has also designed a hydrophilic coated Cloverleaf™ reservoir with a lock-out™ valve mechanism to reduce risk of auto-inflation. The reservoir comes in two volumes, 75 ml and 125 ml for the larger cylinders. The one touch pump with the deflate button allows for easy deflation of the device. The narrow base version of the Titan® Touch allows implantation of prosthesis in patients with fibrosed and or narrow corpora.

Comparably, Boston Scientific manufactures AMS 700™ three-piece inflatable prosthesis. There are 3 variations available in the AMS 700™ inflatable penile prosthesis line.

AMS 700™CX is the standard IPP with controlled expansion of cylinders aiming to optimize girth and offer additional length options.

AMS 700™LGX is the only marketed penile implant with cylinders designed to expand in girth and length of up to 25%.

AMS 700™CXR is the equivalent to the Coloplast narrow base IPP, for narrower or fibrosed corpora.

The AMS 700™ inflatable penile prosthesis line is available in a variety of lengths ranging from 12 cm to 24 cm.

The AMS 700™ spherical reservoir comes in two volumes, 65 ml and 100 ml. Whereas AMS™ Conceal™ flat reservoir comes in 100 ml only. The Conceal™ low-profile reservoir is Parylene coated to enhance durability and optimises fit and flexibility. The AMS Momentary Squeeze (MS) pump™ offers one-touch button designed for easy deflation, it also has a lock-out valve incorporated within the pump mechanism to resist auto inflation.

AMS 700™ is the only antibiotic impregnated inflatable penile prosthesis on the market, it is precoated with Inhibizone™ antibiotic surface treatment. Inhibizone™ is a combination of Rifampicin and Minocycline, it aims to create a zone of inhibition against bacteria that are commonly associated with penile prosthesis infection.

Boston Scientific also markets the only two-piece inflatable penile prosthesis currently available, the AMS Ambicor™. This pre-filled, pre-connected device eliminates the need for a separate reservoir, resulting in a two-piece designed for ease of placement. This device is particularly useful in patients with a history of complex abdomino-pelvic surgery, where retropubic or intraabdominal reservoir placement can be very difficult and to be avoided.

Malleable penile prostheses are an alternative option particularly useful for patients with restricted manual dexterity (e.g. rheumatoid arthritis) or whom require penile projection for other reasons (e.g. placement of urinary containment sheath or for other voiding issues). Both Coloplast and Boston Scientific manufacture malleable penile prostheses which can be an alternative option for patients who do not wish to have a three-piece inflatable penile prosthesis. The Coloplast Genesis™ has a hydrophilic coating in the same way as the Coloplast three-piece devices. AMS Spectra™does not have Inhibizone™ or any other coating (Table 44.5 and Fig. 44.2).

Table 44.5

Coloplast and Boston Scientific penile prosthesis types

Device manufacturer/name	Type	Coating	Length (cm)	Diameter (mm)
Coloplast
Titan One-Touch Release (OTR)	3-piece inflatable	Hydrophilic	14–22 (XL 24–28)	21+
Titan One-Touch Release (OTR) Narrow-base	3-piece inflatable	Hydrophilic	11–18	17
Genesis	Malleable	Hydrophilic	14–27	9.5, 11 & 13
Boston Scientific
AMS 700 CX	3-piece inflatable	Inhibizone	12–24	12–18
AMS 700 CXR	3-piece inflatable	Inhibizone	10–18	9.5–14.5
AMS 700 LGX	3-piece inflatable	Inhibizone	12–21	12–18
AMS Ambicor	2-piece inflatable	None	14–22	12.5–15.5
AMS Spectra	Malleable	None	12–26	9.5, 12 & 14