Surgical Skills Course January 2006

ERECTILE TISSUE SPARING PENILE PROSTHESIS IMPLANTATION

Ignacio Moncada, Juan Ignacio Martinez Salamanca

In most occasions, there is no curative treatment for erectile dysfunction and some kind of symptomatic treatment has to be undertaken. Symptomatic treatment is usually given in a stepwise manner, that is, from a less invasive to a more aggressive approach. Less aggressive approach would be oral drug therapy, a second step is local pharmacotherapy (intracavernosal or transurethral) and the last option would be surgical implantation of a penile prosthesis.

Penile implants offer a dependable way of restoring erections in virtually all motivated patients. The satisfaction rate among both patients and partners using these devices is high (in the range of 90%). Advances in technology have reduced the infection rate and increased the mechanical reliability of these products.

The standard technique of penile prosthesis implantation includes the dilatation of both corpora using the Hegar or Brooks dilators to facilitate the insertion of the cylinders, some surgeons even use the CR Cavernotomes. This maneuver destroys the erectile tissue, probably causes pain in the post-operative period and gives place to a fibrotic response of the tissue.

In the most common case, the virgin implant, there is not need of such dilatation because the erectile tissue is spongy and expands easily and it is the cylinder when inflated the one that compresses the cavernous tissue to make space. This is not the case, obviously, in patients with fibrosis of the cavernosal tissue as it happens in some long standing diabetes, after removal of a previous penile prosthesis, in some patients with Peyronie’s disease or after priapism.

Also, in the majority of patients, there is a residual erectile activity, not sufficient for a rigid erection but producing a noticeable increase in girth and length of the penis; preserving as much erectile tissue as possible might enhance a more natural response to sexual stimulation even in patients implanted with a penile prosthesis.
With these principles in mind we have been using an erectile tissue sparing technique for implantation of inflatable penile prosthesis in a series of patients.

SURGICAL TECHNIQUE

Shaving of the genital area is performed in the operating room to minimize the chance of the skin being colonized by bacteria. The urine culture should be negative if possible in patients who are prone to develop urinary tract infections such as those with neurogenic bladder. Those patients should be placed on antibiotics for a number of days prior to the surgery to maintain sterile urine.

The urinary tract is usually not invaded during the placement of the penile prosthesis, although spilling of urine onto the operative field during the procedure is a possibility, then, for that reason urine must be sterile. Antibiotics are usually started one hour prior procedure; we normally use Cephazolin 2 grams. The antibiotics are usually continued for 48 hours postoperatively, at which time the wound is usually sealed. Some surgeons will prefer to maintain antibiotics for a week after surgery. A catheter is routinely used to identify the corpus spongiosum during the procedure and to empty the bladder at the beginning of the surgery and may be removed at the conclusion of the operation or continued up to the following day of surgery.

We place the prosthesis through a 2 cm vertical incision in the median penoscrotal raphe. A Scott’s retractor is used to keep the wound open and to stabilize the penis. A “window” of dartos is open to reach the tunica albuginea in one side and horizontal mattress sutures are placed before the corpus cavernosum is opened to serve first as stay sutures and then are used to close the corporotomy after device implantation. This technique eliminates placing stay sutures as a separate step, avoids damage to the prosthesis and provides an aesthetic horizontal mattress closure. The critical part of this surgery is appropriate cylinder sizing, not complete dilatation, as is commonly considered.

We simply use the Furlow’s tool advancing it firmly and steady close to the lateral wall of the corpus cavernosum to make sure that we do not enter the septum and crossover the other side. We measure the distal part and then the proximal part with just one passage trying to avoid the cavernosal artery. In normal conditions both corpora are equal in length. The same dartos window is used to dissect the contralateral corpus cavernosum and repeat the operation. The pump and the reservoir are placed in the usual way. We use a Jackson-Pratt drain at the conclusion of the procedure to provide an exit for any bleeding which may occur in the immediate postoperative period. This drain is usually removed the day following the surgery.

CONCLUSIONS

With this technique, the use of dilatators may be avoided and the cavernous artery is preserved. The procedure technically is easy and faster than the standard procedure. We believe that in patients without suspected fibrosis this technique should be of choice.

A clinical study to investigate the advantages or disadvantages of this technique is currently ongoing but preliminary results suggest that patients in whom erectile tissue was preserved during prosthesis implantation are more satisfied than the control group.

QUESTIONS

Question 1
The satisfaction rate among both patients and partners using penile prosthesis is:

1. Less than 50%
2. Approximately 90%
3. Between 40-50%
4. Less in patients that in partners

Correct answer: B
Penile implants offer a dependable way of restoring erections in virtually all motivated patients. The satisfaction rate among both patients and partners using these devices is high (in the range of 90%).

Question 2
The standard technique for the dilatation of both corpora includes dilators called:

1. Furlow dilators
2. Brooks cavernotomes
3. Hegar dilators
4. Wilson device

Correct answer: C
The standard technique of penile prosthesis implantation includes the dilatation of both corpora using the Hegar or Brooks dilators to facilitate the insertion of the cylinders, some surgeons even use the CR Cavernotomes.

Question 3
Which is the main contraindication for implant without dilatation?

1. ED after radical prostatectomy
2. Non-responders to PDE5 inhibitors
3. Suspected fibrosis of Corpora Cavernosa
4. ED after radical cystectomy

Correct answer: C
In the most common case, the virgin implant, there is not need of such dilatation because the erectile tissue is spongy and expands easily and it is the cylinder when inflated the one that compresses the cavernous tissue to make space.  This is not the case, obviously, in patients with fibrosis of the cavernosal tissue as it happens in some long standing diabetes, after removal of a previous penile prosthesis, in some patients with Peyronie’s disease or after priapism.

Question 4
Which is the hypothesis to consider implant without dilatation positive?

1. Lower infection risk
2. Device higher duration.
3. Enhance a more natural response to sexual stimulation after penile implantation
4. Easier in patients suffering fibrosis of the cavernosal tissue.

Correct answer: C
Also, in the majority of patients, there is a residual erectile activity, not sufficient for a rigid erection but producing a noticeable increase in girth and length of the penis; preserving as much erectile tissue as possible might enhance a more natural response to sexual stimulation even in patients implanted with a penile prosthesis.

Question 5
Infection rate of penile prosthesis virgin implant is:

1. About 20%
2. 13,3%
3. 1,8%
4. 35,7%

Correct answer: C
The infection rate using meticulous preparation of the surgical field with antibiotic administration and the possible use of antibiotic-coated prosthesis, is about 2%.