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Posterior Urethral Valves

Everything in the library about posterior urethral valves β€” built automatically from the recorded discussions that name it
episodes total cited expert statements Updated Sep 8, 2026
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Urologic Fetal Intervention: Cincinnati Fetal Center
Dr. Pramod Reddy,Β Division of Pediatric Urology, discussesΒ fetal cystoscopy. Dr. Reddy discusses fetal intervention and risks,Β urinary tract obstructions, open intervention versus fetoscopic intervention, the risks of shunt usage for renal
video61:40 Β· Nov 2018
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Renal transplantation: Fetal Genitourinary Disease 2015
Dr. Maria Alonso, Intestinal Transplant Surgeon, presents on renal transplantations. She discusses general surgical needs, gastrostomy tube, peritoneal dialysis catheter, hemodialysis catheter, extra peritoneal approach, extra vesicle re-im
video13:44 Β· Jan 2019
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Fetal management of advanced chronic kidney disease: Fetal Genitourinary...
Dr. Foong-Yen Lim introduces the challenges of neonatal dialysis, the pathway of renal transplantation, and pulmonary survivor qualifications. Dr. Paul Kingma discusses the pulmonary survivor odds based upon amniotic fluid status and postna
video34:05 Β· Jan 2019
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Urologic Fetal Intervention: Cincinnati Fetal Center
In adult studies, bladder pressure exceeding 40 cm Hβ‚‚O (29 mmHg) causes renal injury and abolishes net glomerular filtration.
clinicalPramod Reddy4:49 β†—
Safe bladder pressures for fetal kidneys are unknown; adult thresholds are used by extrapolation.
clinicalPramod Reddy5:13 β†—
Vesicoamniotic shunts have not improved renal outcomes because the long, thin tubes do not adequately reduce bladder pressure; they provide pulmonary survivors but not renal protection.
clinicalPramod Reddy4:00 β†—
Intravillous pressure that occludes venous flow in the placenta is approximately 23 mmHg; resting amniotic fluid pressure is 5–8 mmHg.
clinicalTodd Ponsky5:43 β†—
When a vesicoamniotic shunt is placed, the bladder often collapses and upper tracts decompress significantly, though residual hydroureteronephrosis may persist.
clinicalGreg Tiao7:38 β†—
Fetoscopic cystoscopy altered the diagnosis in 25–33% of fetuses with suspected LUTO, according to a review by Katie Morris.
host_summaryGreg Tiao11:35 β†—
A French-Brazilian-Houston study of 111 LUTO fetuses found that only cystoscopy (not shunting) may prevent renal function impairment at 6 months of age.
host_summaryGreg Tiao12:09 β†—
In a Barcelona-Leuven series of 20 fetoscopic valve ablations, bladder size and amniotic fluid normalized in 80% of cases; among livebirths, there was no pulmonary hypoplasia and three-quarters had normal renal function.
host_summaryGreg Tiao12:55 β†—
Fetoscopic valve ablation carries a 9–10% risk of urethral fistula and a 6% risk of recurrent severe LUTO.
host_summaryGreg Tiao13:36 β†—
Vesicoamniotic shunt complications include migration, blockage, and (rarely) iatrogenic gastroschisis when placed at 17 weeks.
clinicalGreg Tiao14:06 β†—
The Cincinnati team uses a 3.3 Fr outer sheath fetoscope (1.2 mm scope) with a side port for guidewire passage during cystoscopy.
clinicalFoong Yen Lim30:01 β†—
A flexible 4.9 Fr ureteroscope can be introduced through a 10 Fr sheath to improve maneuverability when accessing the fetal bladder neck and posterior urethra.
clinicalPramod Reddy30:18 β†—
Fetoscopic procedures for LUTO can be performed under epidural anesthesia with IV sedation and local anesthetic, avoiding the deep uterine relaxation required for open fetal surgery.
clinicalFoong Yen Lim24:13 β†—
Fetal anesthesia for fetoscopy includes intramuscular vecuronium, atropine, and fentanyl to prevent fetal movement and mitigate pain response.
clinicalTodd Ponsky24:57 β†—
Serial bladder taps carry a risk of bladder rupture and urinary ascites, which can preclude subsequent fetoscopic intervention.
clinicalFoong Yen Lim22:42 β†—
The Pluto trial removed bladder taps from its protocol because data suggested the most powerful effect of shunting is in poor-prognosis fetuses, and even good-prognosis fetuses have ~50% risk of bad renal function postnatally.
host_summaryTodd Ponsky34:19 β†—
In Mark Johnson's historical studies, the third vesicocentesis provided fresher urine that correlated strongly with histologic renal damage; the first and second taps were not predictive.
epidemiologicalGreg Tiao34:57 β†—
In a long-term follow-up series, one-third of shunted LUTO survivors developed end-stage renal disease requiring transplant after age 5 years, despite having acceptable discharge creatinine.
epidemiologicalGreg Tiao49:58 β†—
Posterior urethral valve patients required transplant at median age 10–12 years; prune belly/urethral hypoplasia at ~4.5 years; urethral atresia earlier.
epidemiologicalGreg Tiao51:24 β†—
Progressive renal injury in shunted LUTO survivors is driven by repeated urinary tract infections, vesicoureteral reflux, and valve bladder dysfunction.
clinicalGreg Tiao52:13 β†—
Creatinine at hospital discharge is misleading; creatinine at age 1 year is a better predictor of long-term renal function. A creatinine <1.0 mg/dL at age 1 suggests the child will not require renal replacement therapy.
clinicalPramod Reddy56:52 β†—
Infants with LUTO triple their birth weight in the first year, revealing the true extent of renal reserve; discharge creatinine does not account for this growth.
clinicalPramod Reddy56:52 β†—
Bladder cycling enabled by fetoscopic valve ablation is physiologically important for bladder health, not for upper-tract protection.
clinicalPramod Reddy16:39 β†—
A urethral fistula from fetoscopic laser ablation can be repaired surgically with minimal morbidity, whereas renal dysplasia cannot be reversed.
opinionPramod Reddy17:57 β†—
Posterior urethral valves can sometimes be ablated by blunt mechanical disruption (guidewire and catheter) rather than laser, because the valves are flimsy.
clinicalPramod Reddy18:30 β†—
Cincinnati performed open fetal vesicostomy in six anhydramniotic fetuses; four died from preterm delivery, one has normal renal function at age 5, and one required transplant.
epidemiologicalPramod Reddy41:33 β†—
Open fetal vesicostomy predisposes the mother to shortened gestation (~10 additional weeks) and very high risk of preterm labor.
clinicalPramod Reddy41:06 β†—
Greg Ryan argues there is no role for open fetal surgery in LUTO, especially in the worst-prognosis group, given the maternal and fetal risks and the experimental nature of the procedure.
opinionGreg Tiao43:12 β†—
Foong Yen Lim proposes that open fetal vesicostomy should be considered only in good-prognosis fetuses who fail fetoscopic intervention, not in the sickest cohort.
opinionFoong Yen Lim45:39 β†—
Current algorithms reserve the most invasive interventions (open vesicostomy) for the worst-prognosis fetuses, which may be flawed because these patients are least likely to benefit and most likely to suffer maternal and fetal harm.
opinionPramod Reddy38:44 β†—
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