Reconstruction of Strictures of the Penile Urethra

The goal of penile urethral reconstruction should be unobstructed micturition from a glanular meatus with excellent cosmesis. Most repairs may be achieved in a single operation utilizing penile skin flaps or skin grafts. Anastomotic urethroplasty should be avoided in the penile urethra, even in short strictures, as tethering and chordee may result. In complex situations such as after previous failed repair, it may be necessary to stage the reconstruction.

Advanced patient age may make one more strongly consider periodic urethral dilation or a permanent first-stage urethroplasty, whereas the younger patient may prefer complex urethral reconstruction. Other patient factors such as adverse wound characteristics (due to concomitant periurethral abscess or fistula) or poor wound healing (due to peripheral vascular disease, diabetes, or prior radiation therapy) should cause one to reconsider proceeding with a complex single-stage urethral reconstruction. Specifically, there has been much debate about the use of the penile skin flap for reconstruction of urethral stricture disease due to lichen sclerosus et atrophicans . In such cases, many prefer substitution with buccal mucosa graft in one or two stages.

Anatomic and Vascular Considerations

The dermis of the penile and scrotal skin is poorly developed ( Fig. 93.1 ). Deep to this is a subdermal vascular plexus. Beneath this is the dartos fascia, which is continuous with the dartos muscle on the scrotum, Colles fascia in the perineum, and Scarpa fascia on the anterior abdominal wall. Deep to Colles fascia is a loose subcutaneous areolar tissue containing the axial arteries of the penis. This layer is often termed the tunica dartos . Below this is the Buck fascia—a multilamellar fascia that surrounds the neurovascular bundle of the erectile bodies dorsally and splits ventrally to wrap around the corpus spongiosum.


Anatomy of the penis.

A thorough understanding of the vascular supply of the penile skin is important in all urethral surgery and particularly essential to successful construction of penile skin flaps. The penile skin derives its blood supply from the superior (superficial) and inferior (deep) external pudendal arteries, branches of the femoral artery. Venous drainage parallels the arterial supply ( Fig. 93.2 ). All the various penile skin flaps are developed based on this blood supply. At the base of the penis, the external pudendal arteries split into ventrolateral and dorsolateral axial penile arteries. These then give off delicate superficial branches to the subdermal plexus. It is incorrect to say that the vessels run in a particular fascia, as fascia is by definition avascular. In fact, the subdermal plexus runs between the skin and the dartos fascia, whereas the subcutaneous plexus runs between the dartos fascia and Buck fascia. Some surgeons describe the axial vessels of the penile skin flaps as being supported by the superficial layer of Buck fascia whereas other describe them as being supported by the dartos fascia.


McAninch: Vascular anatomy of the penis.

Distal Penile Circular Fasciocutaneous Flap (McAninch)

This technique can be used in uncircumcised as well as circumcised men. It yields a hairless flap of up to 15 cm in length and can be used for strictures from the fossa navicularis to the bulbar urethra, making it extremely versatile. The penis is placed on stretch with a 2-0 holding stitch, and the flap is marked out with calipers. The width of the flap varies between 2.0 and 2.5 cm depending on the caliber of the stricture. If the penis is uncircumcised then the inner prepuce is chosen for the flap, whereas if the penis is circumcised then the distal penile skin is used. The distal incision is carried down through the pedicle, leaving the pedicle with the proximal penile skin. Once a satisfactory plane is established, the dissection is continued proximally, degloving the entire penile shaft. The proximal/superficial incision is then made and the pedicle dissected off the proximal penile skin, circumferentially all the way to the base of the penis. This leaves a very mobile circular ring of penile skin supported by a circumferential pedicle ( Fig. 93.1 ). The flap and pedicle are generally divided ventrally as we feel the dorsal branches of the pedicle are more robust ( Fig. 93.3 ). The flap is then rotated 90 degrees and brought around ventrally ( Fig. 93.4 ). The skin island is trimmed to meet the length of the stricturotomy and sutured to the urethral edge in a running fashion with fine absorbable suture over a 16-F catheter ( Fig. 93.5 ). The penile skin is replaced, and the circumcising incision is closed.


McAninch: Ventral division of the skin island and pedicle, leaving a dorsally based flap.


McAninch: Ventral rotation of the flap.


McAninch: Anastomosis of the flap to the urethrotomy.

In cases where the stricture extends to the meatus, the flap can be tunneled under the glans penis and brought out the meatus without the added morbidity of dividing the glans and without having to do a glansplasty. After stricturotomy of the distal penile portion of the stricture, a “glans cap” is raised by dissecting the glans off the corpus spongiosum and the distal tips of the corpora cavernosa ( Fig. 93.6 ). Then the urethrotomy is carried as distally as possible under the glans cap; a ventral meatotomy then joins with the urethrotomy, achieving an adequate lumen ( Fig. 93.7 ). The flap is then tunneled under the glans cap and anastomosed to the cut edges of the meatotomy and then to the cut edges of the distal penile urethrotomy in the standard fashion ( Fig. 93.8 ).


McAninch: Elevation of the glans cap.


McAninch: Ventral meatotomy is joined to the distal penile urethrotomy.


McAninch: ( A ) Skin flap is tunneled under the glans cap; ( B ) skin flap is brought out through the meatus; ( C ) skin flap is anastomosed to the meatotomy.

Longitudinal Ventral Penile Skin Flap With a Lateral Pedicle (Orandi)

This technique is appropriate for strictures of the penile urethra only and has the disadvantage that with proximal extension of the flap one may incorporate hair-bearing skin. With the penis on stretch, a ventral vertical penile shaft incision is made over the area of stricture just lateral to the urethra, approximating the length of the stricture. This incision is deepened to the lateral border of the corpus spongiosum. This will serve as the deep incision ( Fig. 93.9 ). The plane is developed medially over the urethra. A lateral urethrotomy is made contralateral to the side of the initial skin incision and extended proximally and distally until normal urethra is encountered. The lateral urethrotomy helps minimize the amount of flap dissection necessary to obtain a tension-free anastomosis in this flap based on a lateral pedicle ( Fig. 93.10 ). The length and width of the urethral defect are then measured and the flap is marked out in an elongated hexagonal shape. The deep longitudinal incision serves as one of the two long segments of the hexagon, with the second long hexagonal segment becoming the superficial incision ( Fig. 93.11 ). This superficial incision is carried down to but not through the pedicle and developed laterally until the flap can be rotated over onto the urethrotomy in a tension-free manner ( Fig. 93.12 ). Anastomosis of the inner wall (i.e., if the initial skin incision was on the right side and urethrotomy was on the left, the right side of the flap is sewn to the left wall of the urethra) is accomplished with 5-0 monofilament suture in a simple running or subcuticular fashion ( Fig. 93.13 ). The apices and outer wall are closed over a 16F catheter and the penile skin incision is closed ( Fig. 93.14 ).


Orandi: Deep skin incision is made over the area of the stricture (stricture is pictured as if viewed through the skin). Dotted line indicates location for superficial skin incision.

FIGURE 93.10

Orandi: Superficial skin incision.

Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Reconstruction of Strictures of the Penile Urethra

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