16th World Congress in Fetal Medicine

Management of fetal lower urinary tract obstruction with a balloon : a report of three cases Debska M, Kolesnik A, Kretowicz P, Oledzka A, Gastol P, Debski R 2nd Department of Obstetrics and Gynecology, The Centre of Medical Postgraduate Education, Warsaw, Poland

Objective Fetal lower urinary tract obstruction, often associated with presence of posterior urethral valves (PUVs), poses high risk of mortality due to renal failure or pulmonary hypoplasia after birth. A few prenatal procedures can be offered to fetuses with LUTO and presumed isolated PUVs, out of which vesicoamniotic shunting (VAS) is the standard treatment. However, according to literaturę and clinical experience, VAS neither eliminates the cause of the pathology nor effectively prevents vesicoureteral reflux, renal damage and causes bladder spasticity.

Methods Report of three cases of fetal lower urinary tract obstruction and their management.

Results To overcome the technical limitations and to avoid the complications inherent to both fetoscopic procedure and to VAS, we have developed a technique of fetal urethroplasty with a coronary angioplasty balloon catheter, under an ultrasonographic guidance. The coronary catheter is inserted via a 18 - G needle into the fetal bladder and then into fetal . Then the balloon is inserted and slightly inflated to dilatate the urethra. To this date, three such procedures have been performed between 16 - 18 weeks of gestation at our center in male fetuses with megacystis and suspected isolated posterior urethral valves. An unobstructed urine flow was observed in all three cases immediately after the procedure, followed by a resolution of megacystis. One day later USG confirmed decompression of thick - walled and increase of the amniotic fluid volume. Amniotic fluid amount sustained normal until 30 weeks of pregnancy in two of our patients. First patient delivered at 39 weeks of gestation with a 7 - point Apgar score, which reflected presence of transient respiratory problems. During the first day of life, until normalization of respiratory function, the neonate required ventilation in bi - pap. Unfortunately, ultrasonographic exam revealed bilateral renal dysplasia, without parenchymatous differentation. Presence of residual PUVs without urine flow obstruction was confirmed. At the age of 8 months the boy required peritoneal 2 – 3 times weekly. Now he is 15 month's old now, developes normally, he is on dialysis but also urinates independly and exppects transplant to his own bladder. Second patient delivered at 37 weeks of gestation with 10 point Apgar score. USG scans showed bilateral distension of and hyperechogenic kidneys. The neonate underwent a with transurethral incision (TUI) of residual PUVs at cervix of the bladder. Unfortunatelly, due to presence of persistent megaureter on the left side uretero - cutaneous fistula was performed. Currently, the boy is 7 months old now and doesn’t require any renal replacement therapy. Our third patient is currently 25 weeks pregnant, the volume of amniotic fluid is is normal, the kidneys look normally and no signs of urinary flow obstruction has been recorded so far.

Conclusion In search of a method of a causitive treatment of fetal PUVs, we considered urethroplasty with a coronary angioplasty balloon catheter to be an option in prenatal treatment of PUVs. It seems to be less invasive to fetal urethra and surrounding tissues than laser fetoscopy and does not interfere with normal micturition and urinary bladder function, in contrast to VAS. To the best of our knowledge, this is the first report documenting such approach of treatment fetuses with PUV's and it appears to be worth of consideration as an intrauterine treatment of PUV's.