Surgery for benign disorders of the penis, urethra, and scrotal contents

Contributors of Campbell-Walsh-Wein, 12th edition

Ramon Varasoro, Gerald H. Jordan, Kurt A. Mccammon, Dorota J. Hawksworth, Mohit Khera, and Amin S. Herati

Surgery for benign disorders of the penis and urethra

Tenets of reconstructive surgical techniques

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The aims are to minimize tissue injury and promote healing.
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Delicate instruments, including fine tenotomy scissors, forceps, skin hooks, and needle holders, are necessary.
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The smallest possible absorbable sutures should be used to assure tension-free tissue alignment.
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Supine or prone position, rather than high lithotomy, is preferred.

Principles of reconstructive surgery

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Extensibility, inherent tension, stress relaxation, and creep are important in predicting the behavior of transferred tissue.
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A graft is tissue transferred to a host bed, whereas a new blood supply develops by take .
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Urethral reconstruction may employ grafts from full-thickness skin (FTSG), oral mucosa (OMG), bladder epithelium, and rectal mucosa.
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Penile reconstruction employs split-thickness skin grafts (STSGs) , with FTSGs rarely needed. Epidermis and superficial dermal plexus in an STSG convey favorable vascular characteristics. However, physical characteristics are not carried, and graft tends to less durable.
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In a mesh graft , systematic slits in different ratios are placed in an STSG and allow subgraft collections to vent. These conform better to irregular graft host beds, and increased levels of growth factors improve take.
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FTSGs have less predictable vascular characteristics but do not contract as much and are more durable ( Fig. 18.1 A).

Fig. 18.1

Cross-sectional diagrams (histologic appearance above, microvasculature below) of the skin. (A) Cross-sectional diagrams of skin. (B) Cross-sectional diagrams of oral mucosa. FTSG, Full-thickness skin graft; STSG, split-thickness skin graft.

(From Jordan GH, Schlossberg SM. Using tissue transfer for urethral reconstruction. Contemp Urol 1993;13:23.)
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OMGs consist of nonkeratinized mucosa and have optimal vascular characteristics. They can be thinned without impacting the graft’s vascular characteristics ( Fig. 18.1 B).
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Buccal mucosal graft ( BMG ) is harvested from the overlying buccinator muscle in the cheek. It is easy to harvest and handle, resilient to infections, and accustomed to wet environment. It is a standard for urethral reconstruction.
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A flap is transferred with the blood supply preserved or surgically reestablished at the recipient site ( Figs. 18.2 and 18.3 ).

Fig. 18.2

Random flap. The arterial perforators have been interrupted, and flap survival depends on the intradermal and subdermal plexuses.

Fig. 18.3

Axial flaps. Large vessels enter the base of the flaps. Survival depends on these vessels and on the random distal vascularity. (A) Peninsula flap. The vascular continuity and the cutaneous continuity in the flap base are intact. (B) Island flap. The vascular pedicle is intact; the cuticular continuity has been divided. These axial vessels are unsupported (dangling). (C) Microvascular free-transfer flap. The free-flap cuticular and vascular connections are interrupted at the base of the flap. Vascular continuity is reconstituted in the recipient area by a microsurgical anastomosis.

(From Jordan GH, McCraw JB. Tissue transfer techniques for genitourinary reconstructive surgery. AUA Update Series 1988;7:lesson 10.)
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In complex cases, microvascular free-transfer technology is a mainstay. Skin islands based on dartos fascia or tunica dartos are used for urethral reconstruction. Dermal graft may be used to augment the tunica albuginea of the corpora cavernosa.
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Summary of surgical anatomy ( Figs 18.4 through 18.12 )

Fig. 18.4

Top, Cross section of the penis at the junction of its middle and distal thirds. The septum is correctly illustrated as strands that interweave with the tunica albuginea ventrally and dorsally. Bottom, Diagram of a sagittal section of the penis and perineum illustrating the fascial layers. a., Artery; m., muscle; n., nerve; v., vein.

Fig. 18.5

Diagrammatic cross sections of the anterior urethra. (A) The bulbous urethra. The urethra is eccentrically placed in the corpus spongiosum. Proximally, the corpora cavernosa have split into individual crura, with the urethra lying against the triangular ligament. (B) In the shaft of the penis, the urethra is more centrally placed in relation to the corpus spongiosum, and the corpora cavernosa are intimately fused, separated only by septal fibers. (C) At the coronal margin, the urethra remains relatively centrally placed, and the corpora cavernosa are fused, again separated by septal fibers. The spongy tissue of the corpus spongiosum has become incorporated as the deep tissues of the glans. (D) The fossa navicularis widens in caliber and is totally surrounded by the spongy erectile tissue of the glans penis. The urethra here is relatively ventrally placed in relation to the body of the corpus spongiosum.

(From Jordan GH. Complications of interventional techniques of urethral stricture disease: direct visual internal urethrotomy, stents and laser. In Carson C, ed. Topics in clinical urology: complications of interventional techniques. New York: Igaku-Shoin, 1996:86-94.)

Fig. 18.6

Cross sections of the pelvis. (A) The normal attachment of the fasciae enveloping the penile structures. The dartos fascia is contiguous with the Scarpa fascia onto the abdomen, with the tunica dartos of the scrotum, with the Colles fascia on the perineum, and over the thigh, eventually to insert at the fascia lata. (B) With trauma to the pelvis or perineum, the corpus spongiosum is injured; however, the hematoma is confined by the attachment of the Buck fascia. (C) With trauma to the perineum or pelvis, the corpus spongiosum is injured, and the Buck fascia is violated; the hematoma can spread throughout the confines of the extended dartos fascia–tunica dartos system.

Fig. 18.7

Sagittal section of the pelvis. The urethra is subdivided into the following sections: 1, fossa navicularis; 2, pendulous or penile urethra; 3, bulbous urethra; 4, membranous urethra; 5, prostatic urethra; and 6, bladder neck. By common usage, the divisions of the fossa navicularis, pendulous urethra, and bulbous urethra compose the anterior urethra, and the divisions of the membranous urethra, prostatic urethra, and bladder neck compose the posterior urethra.

(Modified from Devine CJ Jr, Angermeier KW. Anatomy of the penis and male perineum. AUA Update Series 1994;8:11)

Fig. 18.8

Diagrammatic representation of the sphincters surrounding the male posterior urethra.

Fig. 18.9

The vasculature to the genital skin. (A) The superficial external pudendal vessels arborize to become the fascial blood supply contained in the dartos fascia of the penis. (B) The scrotal artery is a terminal branch of the deep internal pudendal artery. This artery is thought to arborize in the tunica dartos of the scrotum and Colles fascia of the perineum. The perineal artery continues lateral to the groin crease onto the thigh and extends toward the groin. a., Artery; v., vein.

Fig. 18.10

The venous drainage of the deep structures of the penis.

(From Horton CE, Stecker JF, Jordan GH. Management of erectile dysfunction, genital reconstruction following trauma and transsexualism. In: McCarthy JG, ed. Plastic surgery, vol 6. Philadelphia: Saunders, 1990:4213-4245.)

Fig. 18.11

The arterial supply to the deep structures of the penis.

(From Horton CE, Stecker JF, Jordan GH. Management of erectile dysfunction, genital reconstruction following trauma and transsexualism. In: McCarthy JG, ed. Plastic surgery, vol 6. Philadelphia: Saunders, 1990:4213-4245.)

Fig. 18.12

“Peel-away” diagrams of the anatomy of the perineum. (A) The skin and subcuticular tissues have been removed. (B) In the anterior perineal triangle, Colles fascia has been removed. In the posterior anal triangle, the pelvic diaphragm has been removed. Note the division of the superficial transverse perineal muscle, exposing the deep transverse perineal muscle. (C) The anterior perineal triangle has been dissected to expose the erectile bodies. (D) The corpus spongiosum has been divided at the departure of the urethra from the penile bulb. The intracrural space is exposed.

(From Devine CJ Jr, Angermeier KW. Anatomy of the pelvis and male perineum. AUA Update Series 1994;13:1015.)

Selected processes

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Lichen Sclerosis (LS) – Previously called balanitis xerotica obliterans; thought to be premalignant for squamous cell carcinoma of the glans, so biopsy needed; most common cause of meatal stenosis; management of LS-related strictures is complex and often suboptimal.
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  If only foreskin involved, circumcision may be curative.
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  Combination of topical steroids and tetracycline may stabilize inflammatory process.
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  Consider intermittent catheterization and 0.05% clobetasol when meatus is easily maintained at 14–16 Fr.
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  Surgical reconstruction is often with BMG and staged. However, due to skin involvement with LS, genital flaps and grafts have a high failure rate in this population.
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Urethrocutaneous Fistula – Epithelium-lined tract; may be a complication of urethral surgery or from periurethral infections, inflammatory strictures, or treatment of a urethral growth; treatment should focus on defect and underlying cause.
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  Small fistula may be closed with layered, watertight closure (6-0 or 7-0 absorbable sutures); avoid superimposed suture lines; maintain girth of urethral lumen.
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  For large fistula, utilize local flaps; tunica dartos provides tissue interposition and minimizes superimposed suture lines; suprapubic tube (SPT) urinary diversion.
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A congenital urethral diverticulum is a pouch lined with transitional cell epithelium; result of either segmental, urethral distention or attachment of a structure to urethra by narrow neck; in males, may result from incomplete development of anterior urethra or result of straddle trauma causing intracorporeal spongiosal hematoma; a Müllerian duct remnant may cause congenital diverticulum in the prostatic urethra; in proximal hypospadias, diverticulum represents an enlarged utricle.
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Paraphimosis is painful swelling of foreskin distal to phimotic ring; occurs when foreskin is retracted but not reduced.
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Urethral meatal stenosis in young boys is a consequence of circumcision; ammoniacal meatitis develops, which heals with a membrane across ventral meatus.
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All failed hypospadias repairs should be evaluated for urethral stricture disease.