A guide for parents of children with posterior urethral valves
What is a posterior urethral valve?
The posterior urethral valve is a thin curtain-shaped structure that prevents the discharge of urine from the bladder formed in the boy's urethra (the tube-shaped structure that extends from the bladder to the urethra that allows urination). These structures, which prevent the discharge of urine from the bladder, may cause enlargement of the bladder, ureters and kidneys, malfunctions, and kidney failure over time. According to the severity of the obstruction of this structure, the severity of these changes in the urinary tract increases.
What is the cause and how often does it occur?
The posterior urethral valve appears in the early stages when the baby boy starts to develop in the intrauterine period. During this period, children urinate and form most of the mother's uterine fluid called amniotic fluid. As urine output decreases in these children, a decrease in amniotic fluid also occurs. When the child cannot empty the bladder easily, urine starts to accumulate in the bladder and the pressure increases. This increases the pressure of urine from the bladder to the kidneys, causing swelling of the kidneys and ureters. This pathological condition is called hydroureteronephrosis. Even in the early stages of pregnancy, this swelling in the baby's kidneys can be detected by the ultrasonography method. It occurs in 1 in 8 thousand live births. It is not an inherited disease.
What are the symptoms and signs?
Different clinical pictures are encountered from mild to very severe. After birth, the baby has difficulty urinating depending on the severity of the obstruction. Irritations, drips, and weak urination or incontinence may occur. Severely swollen kidneys and bladder can be easily noticed externally or palpated on examination. Children may also present with a serious picture called sepsis because of urinary tract infection or the mixing of the bacteria causing the infection into the blood. On the other hand, it can be diagnosed without any symptoms.
How is it diagnosed?
Voiding cystourethrography is used for diagnosis. With the help of a catheter placed in the bladder through the urethra, radio-opaque material is introduced into the bladder and films are taken during urination. It is investigated whether there is leakage towards the kidney (vesicoureteral reflux) and whether there is obstruction during voiding. In the films obtained with this examination, it is seen that most of the urine stays in the bladder, the part of the urethra before the valve, the bladder, and the ureter and kidneys enlarge depending on the severity of the disease. Ultrasonography evaluates whether there is enlargement in the kidneys and ureters.
What are the requirements of the surgical procedure?
This surgical procedure should be performed in children with posterior urethral valve-related urination difficulties, growth retardation, swelling in the bladder and kidneys, and urinary tract infection.
How is the follow-up of these babies during pregnancy and early postnatal period?
If the baby was diagnosed in the intrauterine period; It is recommended that the child be delivered immediately after completing its development, without waiting for the term. As soon as the child is born, a catheter is inserted so that he or she can urinate easily. In this way, the pressure in the bladder and kidneys decreases and the general condition of the child begins to improve. If there is a urinary tract infection, it is treated. These valves should be removed when the child's general condition improves, the infection clears, and the child reaches sufficient weight for anesthesia.
How is the pre-operative preparation in children?
The procedure is performed under sterile conditions in the operating room under general anesthesia. For this reason, children are left hungry and dehydrated 4-6 hours before the operation. Prophylactic antibiotic treatment is started 1 day before the operation.
How is surgical treatment done?
The treatment of the posterior urethral valve is surgery. Treatments may vary depending on the severity of the condition, your child's age, the condition of the bladder and kidneys, and the extent to which the curtain is obstructing the urinary tract.
Valve ablation: After diagnosing a posterior urethral valve, the leaflet or web should be surgically cut, and the urinary tract should be relieved. The urethra, bladder and bladder neck are examined with the help of a lighted camera that is advanced to the bladder through the urethra. It is examined whether there is a defect in the wall structure of the bladder and whether the ureteral holes are normal. The urethra is opened by cutting the curtains covering the urethra. The procedure is terminated by placing a urinary catheter in the bladder.
Vesicostomy: It is the opening of the bladder to the skin. If the baby is too small for valve ablation, or if the kidneys and bladder are severely affected by the posterior urethral valve, an operation under general anesthesia is performed under general anesthesia to mouth the bladder to the skin, so that urine can flow freely outward or into the gland.
How are these children followed and what are the complications?
After establishing adequate urine flow with vesicostomy or valve ablation, the condition of the urinary tract and development of the kidneys should be checked at regular intervals. During these follow-ups, decisions are made about toilet training, initiation of different drugs or performing additional surgeries.
The most common complication is re-narrowing of the valves and the need for a second surgery. Sometimes the number of operations may be more than two. Despite the successful outcome of the surgery, this leakage may continue in children with advanced renal leakage. In such cases, separate surgeries may be required to correct this back leak. If the urinary bladder is mouthed from the navel level to the patient, this may lead to bladder laziness. Chronic renal failure, need for dialysis and severe resistant infections may develop especially in children with late diagnosis, very severe disease, and delayed treatment. The child's development may be impaired and may result in death. Even after a successful operation, the child should be followed closely by the doctor.