Abnormalities of the male urethra and webbed penis

Abnormalities of the male urethra are common and the need for treatment depends on the condition and the symptoms. Epispadias and hypospadias may result in difficulty urinating and infections, and surgical repair is indicated for restoring functionality and reconstruction of external genitalia. Posterior urethral valves are the most common cause of urinary obstruction in newborn boys and can be associated with hydronephrosis, renal failure, and pulmonary hypoplasia. Early identification by prenatal ultrasound with diagnosis by voiding cystourethrogram allows for cystoscopic valve ablation and relief of the obstruction. However, despite treatment, many patients will develop chronic kidney disease.

• Definition
  • Embryonic malformation due to malpositioning of the genital tubercle that causes incomplete urethral tubularization on the dorsal penis when associated with bladder exstrophy, although in an attenuated form
  • May also be due to chronic pressure, e.g., as a result of a transurethral indwelling catheter eroding the urethra.
• Epidemiology: incidence is about 2.4 per 100,000 live births (isolated epispadias) ^[1]
• Clinical features ^[2]
  • Cleavage and exposure of the urethra
    • On the dorsal penis and associated with penile curvature
    • Between labia and clitoris or up to bladder
  • Urinary incontinence, vesicoureteral reflux
• Diagnostics: clinical diagnosis
• Treatment
  • In young patients: operative closure with urethroplasty and reconstruction of genitalia if indicated
  • In patients with long-term indwelling catheters: insertion of a suprapubic indwelling catheter (reconstructive treatment is usually not necessary)
• Complications
  • Erectile dysfunction and infertility in males
  • UTI

• Definition: common congenital malformation with incorrect positioning of the external urethral meatus; due to failure of urethral folds and foreskin to fuse on ventral penis
• Epidemiology: incidence is 1 per 250 live births ^[3]
• Etiology: Genetic (e.g., differences of sex development), endocrine (e.g., 5-alpha reductase deficiency), and environmental factors have been implicated.
• Clinical features
  • Abnormal foreskin; (dorsal hood), ventral penile curvature; , and two meatal openings
  • Proximal hypospadias are associated with bifid scrotum and penoscrotal transposition
  • Associated with inguinal hernias, cryptorchidism, and chordee (a congenital abnormality characterized by an abnormal ventral curvature of the penis)
• Diagnostics: clinical diagnosis
• Treatment
  • Mild cases do not necessarily require surgery
  • Significant displacement or symptomatic micturition warrants surgical repair
    • Reconstruction of urethra, penis, and scrotum at 6 months of age: urethroplasty and orthoplasty
    • Severe cases require two-stage repair with correction of penile curvature first followed by urethroplasty at least 6 months later
• Complications (following repair)
  • Urethral fistula
  • Meatal stenosis: narrowing of ventral meatus causes thin urinary stream and straining with urination
    • Most commonly caused by circumcision
    • Treatment consists of surgery: meatotomy (the meatus of the urethra is ventrally incised)
  • Urethral diverticulum: distinct outpouching of the urethral mucosa that most frequently leads to dribbling, dysuria, and dyspareunia.
  • UTIs

Circumcision is contraindicated in boys with hypospadias that includes the foreskin. In these cases, the foreskin may be needed for a skin flap when performing urethroplasty.

• Definition: congenital malformation in males where membranous folds of the urogenital membrane obstruct the membranous and prostatic urethra (posterior urethra)
• Epidemiology: incidence is about 1 per 4,000 live births ^[4]
• Clinical features ^[2]
  • Most common cause of urinary tract obstruction in newborn males
  • Respiratory distress secondary to pulmonary hypoplasia in cases with severe obstruction (see “Potter sequence”)
  • Abdominal distention due to bladder distention
  • Late manifestations:
    • Difficulty voiding, poor urinary stream
    • UTIs → urosepsis
    • Diurnal enuresis
    • Failure to thrive
• Diagnostics
  • Voiding cystourethrogram (diagnostic study of choice) demonstrates
    • Dilation/elongation of the posterior urethra during voiding
    • Signs of vesicoureteral reflux (if present)
  • Prenatal ultrasound of the upper urinary tract may demonstrate:
    • Distended and/or thick-walled bladder
    • Bilateral hydroureters
    • Bilateral hydronephrosis
    • Marked vesicoureteral reflux with megaureter
    • Oligohydramnios and features of Potter sequence (in severe urinary outflow obstruction)
• Treatment
  • Temporary insertion of urinary catheter and correction of electrolyte imbalance
  • First-line: primary valve ablation
    • An endoscopic procedure that involves the transurethral incision of posterior urethral valves in the membranous part of the urethra
    • Performed during cystoscopy
  • Second-line: vesicostomy
    • A surgical procedure in which a connection is formed between the bladder and the outside of the lower abdominal wall to allow for the drainage of urine (or if ablation is not possible)
    • Also indicated in patients with functional bladder outlet obstruction (e.g., neurogenic bladder)
  • Close follow-up due to high risk of chronic kidney disease
  • Renal transplantation may become necessary during the course of disease.
  • Fetal vesicoamniotic shunting is associated with procedure-related risks without evidence of long-term benefits for renal function
• Complications: most common cause of chronic renal insufficiency or renal failure in boys

• Definition
  • A congenital malformation with growth of the scrotum extending to the tip of the penis (usually only extends to the root of the penis)
  • The urethra is typically not affected.
• Clinical features
  • Formation of webbing between the tip of the penis and the scrotum when erect
  • Potential erectile dysfunction and ventral deviation
• Diagnostics: clinical diagnosis
• Treatment
  • Early surgical correction with suturing of the scrotum to the penile shaft
  • Generally for cosmetic reasons

References:^[5]