[Acute Kidney Failure Due to Urachal Cyst?]

Area of Science:

• Pediatric Surgery
• Neonatal Urology
• Medical Imaging

Background:

• A newborn presented with suspected fetal malformation, prenatal renal impairment, and anhydramnios.
• The infant also exhibited external stigmas of trisomy 21 and progressive postnatal renal impairment with anuria.

Observation:

• Prenatal ultrasound showed unilateral renal agenesis and an undetectable bladder.
• Postnatal ultrasound revealed enlarged kidneys with impaired perfusion and a rosette-shaped structure in the lower abdomen.
• Exploratory laparotomy identified the structure as a persistent urachal cyst obstructing the upper urinary tract.

Findings:

• Surgical removal of the urachal cyst and bladder reconstruction led to complete renal function recovery.
• A subsequent voiding cystourethrogram unexpectedly diagnosed a posterior urethral valve, which was treated surgically.
• The exact cause of initial renal failure remains unclear, possibly due to the urachal cyst's mass effect or a masked proximal stenosis.

Implications:

• This case highlights the importance of investigating unusual abdominal structures in neonates with renal dysfunction.
• Prompt surgical intervention for urachal cysts and associated urinary anomalies can lead to favorable renal outcomes.
• The interplay between urachal cysts and posterior urethral valves in neonatal renal failure warrants further investigation.