Failure of ventral urethral folds to fuse and form penile urethra (paucity of ventral skin). Leads to 3 deformities

1. Ventral urethral meatus
2. Chordee (ventral curvature) due to relative shortening of ventral structures
3. "hooded" dorsal foreskin.

Risk factors

• Poor placental oxygen flow during development
• Placenta delivers hCG which is an LH surrogate for androgenization
• Smoking, advanced maternal age, prematurity, placental insufficiency
• Paternal hypospadias
• Genetic syndromes - Denys-Drash, WAGR

1. Ventral urethral meatus
2. Chordee (ventral curvature)
3. "hooded" dorsal foreskin.

Classification based on meatus location

• 1st°/mild/distal - glanular to subcoronal (can have normal urinary stream) (50%)
• 2nd°/moderate/middle - distal shaft to posterior penile (30%)
• 3rd°/severe/proximal - penoscrotal to perineal (20%)

Variant: megameatus intact prepuce (intact foreskin, retract to reveal glanular cleft)

Typically an isolated abnormality

• Not associated with upper GU abnormalities
• ~10% a/w cryptorchidism, inguinal hernia
• If + cryptorchidism or if proximal hypospadias, work up for DSD (karyotype, GU US, serum lytes for CAH)

If foreskin is abnormal, do not circumcise at birth (difficult, and foreskin is used in repair)

Surgery at 6-12 mo old (post-op management of toddlers with toilet training is difficult)

• Goal of repair: straight penis with slit-like meatus on glans for forward-directed urinary stream
• Optional: give testosterone 25-50 mcg IM x 1-2 at 3 week intervals before surgery to increase penis/prepuce size for repair

Chordee correction eg orthoplasty

• Observe with artificial erection (butterfly needle in cavernosum + saline instillation).
• Can correct with dorsal plication, but limit # of sutures to prevent shortening
• Artery and nerve are just lateral to midline; midline suture does not need to elevate NV bundles (Baskin suture)
• Severe curvature (>30 degrees) may require transverse corporotomies to release the curvature, or dermal graft to corpora which would require transection of urethral plate (maintains distal blood supply from glans)
•  
• 

Meatus repair techniques

• TIP aka Snodgrass - tubularized urethroplasty +/- incision of urethral plate.
• Commonly used for distal defects, can be used for proximal as well
• Urethral plate can be incised for midshaft/proximal hypospadias, and heals by re-epithelialization without stricture
• "Thiersch Duplay principle" = tubularization
• Slightly higher complication rate than MAGPI (4% vs 1%) of fistula/stenosis
• 
• E shows a dartos flap (increase amount of tissue between neourethra and skin to minimize risk of fistula)
• MAGPI - meatal advancement and glanuloplasty
• Indicated for glanular hypospadias with 'flat' glans
• 
• Mathieu inframeatal flap 
• 
• Proximal hypospadias - likely 2 stage repairs with flaps vs grafts

Postop:

• Oxybutynin (bladder spasms will push urine around catheter/onto sutures), pain control
• 6Fr Kendall catheter x 5-10 days(?)

Complications

• Meatal retraction
• Urethral stricture
• Urethro-cutaneous fistula (15%)
• About 1/2 will close spontaneously, observe for 6 mo before surgery
• Urethral diverticulum