Bladder outlet obstruction

IntroductionFetal bladder outlet obstruction (or lower urinary tract [LUTO]) is most commonly caused by posterior urethral valves and atresia can lead to abnormal renal development pulmonary hypoplasia. It associated with a high rate of perinatal morbidity mortality.DefinitionPrenatally detected LUTO occurs because blockage in the (the outlet) developing fetus leads megacystis, thickened wall, bilateral hydronephrosis or without cystic dysplasia parenchyma.Ultrasound FindingsIn first trimester pregnancy, an enlarged bladder, defined as sagittal length >7 mm.1Sebire N.J. Von Kaisenberg C. Rubio Snijders R.J. Nicolaides K.H. Fetal megacystis at 10-14 weeks gestation.Ultrasound Obstet Gynecol. 1996; 8: 387-390Crossref PubMed Scopus (117) Google Scholar, 2Liao A.W. Sebire Geerts L. Cicero S. Megacystis gestation: chromosomal defects outcome according length.Ultrasound 2003; 21: 338-341Crossref (136) 3Kagan K.O. Staboulidou I. Syngelaki A. Cruz J. The 11-13-week scan: diagnosis holoprosencephaly, exomphalos megacystis.Ultrasound 2010; 36: 10-14Crossref (72) Scholar After there no single definition many different definitions found literature.4Taghavi K. Sharpe Stringer M.D. megacystis: systematic review.J Pediatr Urol. 2017; 13: 7-15Abstract Full Text PDF (35) One study normal gestational age minus 5 mm (±95% upper confidence interval [CI]=7); was greater than limit 95% CI for age.5Maizels M. Alpert S.A. Houston J.T. Sabbagha R.E. Parilla B.V. MacGregor S.N. length: simple monitor assess fetal size, forecast clinical outcome.J 2004; 172: 1995-1999Crossref (30) A wall one that measures >3 mm. Hydronephrosis dilation pelvis, measured anteroposterior diameter, ?4 second pregnancy ?7 third (Figure 1). dilated urethra, also known “keyhole” sign, 2). In addition, ureteral may be seen reflux from pressure. kidneys develop become echogenic atrophied.Figure 2Markedly bladderShow full captionThe asterisk indicates distended proximal giving characteristic keyhole appearance valves. Oligohydramnios present.Society Maternal-Fetal Medicine. SMFM Anomalies Consult Series #4. Am J Gynecol 2021.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Associated AbnormalitiesMost cases (78%) are isolated.6Malin G. Tonks A.M. Morris R.K. Gardosi Kilby Congenital obstruction: population-based epidemiological study.BJOG. 2012; 119: 1455-1464Crossref (99) often oligohydramnios, possibly leading clubbed feet Urinary ascites perinephric urinomas occur result kidney rupture.Differential DiagnosisThe common etiology (63%), which congenital membranes urethra act block micturition. Classic features include (“keyhole” sign), cortical cysts, oligohydramnios. Urethral (10%) have same greatly although appearance. Unlike valves, only males, both male female fetuses.6Malin ScholarOther conditions differential Prune-Belly syndrome triad lax absent abdominal musculature; thin-walled, bladder; cryptorchidism), aneuploidy (most trisomy 13,18, 21), megacystis-megaureter (severe vesicoureteral reflux), megacystis-microcolon (thin-walled urethra; increased amniotic fluid).6Malin Scholar,7Ruano R. Dunn T. Braun M.C. Angelo J.R. Safdar Lower intervention based on prenatal staging.Pediatr Nephrol. 32: 1871-1878Crossref (33) fetus, vagina septal anomaly mimic bladder. persistent cloaca (convergence rectum, perineal opening) should considered. large case series 26.9% diagnoses were falsely positive. final postnatal these (24.5%), cloacal dystrophy (18.9%), (11.3%). cases, resolved during pregnancy.6Malin ScholarGenetic EvaluationDiagnostic testing amniocentesis chorionic villus sampling microarray analysis (CMA) offered when detected. If severe oligohydramnios make not feasible, done placental biopsy fluid obtained vesicocentesis. ultrasound findings screening test results suggest aneuploidy, it reasonable initially perform karyotype fluorescence situ hybridization, reflex CMA if normal. additional anomalies, consanguinity, family history specific condition, gene panel exome sequencing sometimes useful does detect single-gene (Mendelian) disorders. pursued, appropriate pretest posttest genetic counseling provider experienced complexities genomic recommended. counseling, cell-free DNA option patients who decline diagnostic evaluation particularly suspected.Pregnancy Delivery ManagementGiven poor prognosis LUTO, termination offered. Shared patient decision-making requires thorough multidisciplinary regarding prognosis. For continue their serial vesicocenteses been suggested function help determine whether controversy benefit prognostic markers.7Ruano Fluid completely removed two three times sequentially measure electrolytes degree refilling. Normal values urine follows: sodium<100 mg/dL, chloride<90 osmolarity<200 mOsm/L, calcium<8 total protein<20 beta-2-microglobulin<4 mg/dL.8Abdennadher W. Chalouhi Dreux et al.Fetal biochemistry 13-23 gestation criteria in-utero treatment.Ultrasound 2015; 46: 306-311Crossref vesicocentesis, subsequent examination refills. absence refill usually dysfunction, further recommended.7Ruano ScholarA staging system recommended therapies has established.7Ruano Possible interventions cystoscopy, vesicoamniotic shunt, amnioinfusion. Cystoscopy allow therapy guidewire passage through laser ablation PLUTO (Percutaneous shunting Tract Obstruction) trial, shunt did increase survival 28 days compared conservative management intention-to-treat but actual treatment. Morbidity mortality very groups, complications.9Morris Malin G.L. Quinlan-Jones E. al.Percutaneous versus (PLUTO): randomised trial.Lancet. 2013; 382: 1496-1506Abstract (234) Serial amnioinfusions proposed reducing risk hypoplasia, data limited, research needed role this intervention.10Haeri Simon D.H. Pillutla palliation fetuses failure.J Matern Neonatal Med. 30: 174-176Crossref (12) ScholarParents desire resuscitation deliver center level IV neonatal intensive care unit (NICU). general, mode delivery usual obstetrical indications parents’ preferences cases. Planned preterm demonstrated benefit.PrognosisLUTO mortality. worst presence early, severe, prolonged hypoplasia.11Kilbride H.W. Yeast Thibeault D.W. Defining limits survival: lethal hypoplasia after midtrimester premature rupture membranes.Am 175: 675-681Abstract (106) Scholar,12Nakayama D.K. Harrison M.R. de Lorimier A.A. Prognosis presenting birth.J Surg. 1986; 43-45Abstract (116) Other parenchymal abnormalities urinalysis. significant percentage will end-stage disease require dialysis transplantation.13Morris Long-term neurodevelopmental infants intervention.Early Hum Dev. 2011; 87: 607-610Crossref (36) These NICU stay, gastrotomy tube several years, prone infections mechanical failures. cause damage child clean intermittent catheterization surgeries achieve continence birth throughout life.SummaryFetal characterized hydronephrosis. rate. Vesicocentesis evaluate possibility intervention, optimal outcomes unclear. Interventions reported cystoscopy valve, shunting, Despite poor, rates disease, dysfunction. DefinitionPrenatally parenchyma. Prenatally Ultrasound atrophied. Associated rupture. Most Differential Genetic suspected. Diagnostic Pregnancy benefit. Given Parents PrognosisLUTO life. SummaryFetal