GU Ultrasound in First Trimester

Transcription

1 Fetal Renal Malformations: The Role of Ultrasound in Diagnosis & Management Outline 1. Renal Anomalies Urinary Tract Dilation Aberrant Early Development Defects Terminal Maturation Alfred Abuhamad, M.D. Eastern Virginia Medical School Fetal Bladder Bladder Bladder Bladder GU Ultrasound in First Trimester 13 weeks 13 weeks 12 weeks 4 Fetal Bladder Fetal Bladder Seen in 88 % at 12 weeks Seen in % at 13 weeks Renal source of AF is > 16 weeks 12 weeks Ultrasound Obstet Gynecol 2003; 21: Ultrasound Obstet Gynecol 1996; 7:

2 Normal Bladder Length < 7mm Megacystis (7-15 mm) Chromosomal anomalies in 24% With normal chromosomes: Resolution in 90 % Renal anomalies in 10 % 12 weeks Ultrasound Obstet Gynecol 2003; 21: 338 Megacystis (12 mm) Megacystis (> 15 mm) Chromosomal anomalies in 11% With normal chromosomes: Renal anomalies in 100 % Normal (6 mm) 9 Ultrasound Obstet Gynecol 2003; 21: 338 Axial Kidneys Kidneys (First Trimester) Kidneys A 11 weeks B 13 weeks 2

3 Coronal Fetal Kidneys Adrenals Kidneys Seen in % at 12 weeks Seen in % at 13 weeks Adrenals Kidneys Most Optimal in First Trimester Ultrasound Obstet Gynecol 1996; 7: Fetal Sex Inaccurate before 12 weeks Accuracy increases with advancing gestational age Greater than 95% at > 13 weeks Female Obstet Gynecol Surv 2009; 64: Male 16 Classification of Renal Malformations Cell biology Genetics Embryology Urinary Tract Dilation Aberrant Early Development Defects Terminal Maturation UPJ UVJ UV Reflux Megaureter PUV Urethral Atresia Spectrum with significant overlap MCDK Duplex Aplasia Hypoplasia Ectopic Kidney Fusion Disorders Syndromes ARPKD ADPKD Urinary Tracy Dilation Ureteropelvic Junction Obstruction Ureterovesical Junction Obstruction Vesicoureteral Reflyux Lower Urinary Tract Obstruction Prune Belly Syndrome 3

4 Urinary Tract Dilation - Dilated renal pelvis (+/- calyces) - Nonvisible distal ureter (normal) - Normal Bladder Refer to: Ureteropelvic Junction Obstruction Etiology Physiologic (functional) Maternal hormones Over hydration Upper ureteral stenosis Obstruction by an overriding vessel Schematic from: Renal Pelvis Dilation Can we differentiate prenatally? - Obstructive - Physiologic Increase by 2-3 mm More dilation Calyceal involvement Progressive worsening Suggest Obstructive Obstet Gynecol 1998;92: Urinary Tract Dilation Ureteropelvic junction (UPJ) obstruction 30% What is a dilated renal pelvis? Vesicoureteric reflux (VUR) 10% Utereterovesical junction (VUJ) obstruction 1% Transient or physiologic 58% Vesico-outlet obstruction 1% 4

5 Ureteropelvic Junction Obstruction Parameter Measurement Notes Anterior-Posterior Renal Pelvic Diameter (APRPD) (mm) Measured on transverse image at the maximal diameter of intrarenal pelvis weeks 28 weeks Postnatal <4mm <7mm < 10mm Epidemiology 1/3 of all UTD 1 in 1,000-2,000 live births M:F 2:1 90% unilateral 2/3 involve the left kidney 12% associated with extrarenal anomaly Schematic drawing retrieved from Ureteropelvic Junction Obstruction Massive dilation of renal pelvis without dilated calyceal system, implies lesser degree of obstruction Intrarenal dilation poses a risk for loss of function Ureteropelvic Junction Obstruction Progressive dilation Poor prognosis 23 weeks 28 weeks 32 weeks Ureteropelvic Junction Obstruction Ureteropelvic Junction Obstruction Can UPJO resolve spontaneously? Mild cases almost always resolve in months Severe cases will show improvement in 70-80% Can we predict need for surgery on prenatal sonography? J Urol 2002;168:1118 BJU Int 2003;91(9):850 Urology 2009;73(3):521 Schematic drawing retrieved from Schematic drawing retrieved from 5

6 Ureteropelvic Junction Obstruction If function is low, can successful surgery improve it? Fetal UTD of 18 mm Neonatal UTD of 16 mm Sensitivity of 100% Specificity of 86 % (95% CI ) When function is low, it is unlikely to improve Goal of surgical intervention is to preserve current function Journal of Urology 2013;190:661 J Urol 1999;162:1041 Schematic drawing retrieved from - Dilated renal pelvis (+/- calyces) - Dilated distal ureter - Normal Bladder Etiology Urinary Tract Dilation Ureterovesical Junction obstruction Megaureter Vesico-ureteral reflux Duplex kidney Schematic drawing retrieved from Urinary Tract Dilation - Dilated renal pelvis (+ calyces) - Dilated distal ureter - Abnormal dilated thickened bladder Lower Urinary Tract Obstruction Etiology Posterior urethral valves in 50-60% Urethral atresia in 20-40% Urethral stenosis Prune belly syndrome Cloacal dystrophy Megacystis-microcolon syndrome Pediatric Urology. 2014; 84 (1)185. Schematic drawing retrieved from 6

7 Dilated renal pelvis Dilated ureter Abnormal bladder Vesico-Outlet Obstruction Megacystis Thickened bladder wall > 3mm Keyhole sign: dilated posterior urethra Bilateral hydronephrosis or cortical cysts Oligohydramnios Vesico-Outlet Obstruction First Trimester Vesico-Outlet Obstruction Prenatal Evaluation Detailed ultrasound Amniocentesis (vesicocentesis) for CGH Assess kidneys (size, echogenicity, cortical cysts) Evaluate urine for prognostic indices Comprehensive counseling of parents Vesico-Outlet Obstruction Bladder Rupture How Good are we in Predicting Prognosis? 7

8 Vesico-Outlet Obstruction Evaluation of Kidneys Look for obstructive cystic dysplasia Small Echogenic Cystic changes Oligohydramnios Poor Prognosis Vesico-Outlet Obstruction Evaluation of Renal Function J Pediatr Surg Aug;20(4):376 - Pediatric Research. Nov 2012; 72(5):446 J Urol 2004;172:852 Vesico-Outlet Obstruction How Good are we in predicting Prognosis? Ultrasound Urine electrolytes Marginally Predictive of Poor Outcome Recent study suggests improved prediction by using 12 urinary proteins (PUV12) Prenatal Diagnosis 2007;27:900 Sci Transl Med 2013;5:198. Vesico-Outlet Obstruction How Good are we in predicting Prognosis? Normal AVF EGA at diagnosis > 24 weeks Predictive of Good Outcome LUTO- Therapeutic Intervention Vesico-amniotic shunt Fetal cystoscopy - Laser Lancet 2013; 382:

9 Treatment of Obstruction How Effective is Shunting as a Therapeutic Intervention? J of Urology 2005;174:1031. Long-term Outcomes in Children Treated by Prenatal Shunting Renal Function: 45% acceptable 22% mild insufficiency 33% dialysis and/or transplant Treatment of Obstruction Retrospective cohort study of 111 fetuses with obstruction Patients offered fetal cystoscopy, vesico-amniotic shunting or no intervention Intervention N Survival rate Of survivors, normal renal function at 6 months Fetal cystoscopy 34 44% 75% Vesicoamniotic shunting 16 38% 60% None 61 20% 40% Compared to no intervention Both interventions associated with statistically significant increased survival (RR , P= ) Fetal cystoscopy significantly improved 6 months renal function in cases of posterior urethral valves (P=0.03) Obstet Gynecol 2005;106:503 Ultrasound Obstet Gynecol, 2011; 37: Treatment of Obstruction 50 fetal cystoscopies (31 with PUV 1 trisomy 18) Year 1: 17/30 (56.7%) survived, 13/17 (76.5%) had normal renal function Year 2: 15/28 (53.6%) survived, 11/15 (73.3%) had normal renal function Vesicoamniotic shunting (VAS) and cystoscopy improves survival over conservative management Long-term impact on renal function is poor with VAS and conservative management Cystoscopy appears to improve long-term renal function, but there is lack of robust data at this stage Prenatal Diagnosis 2016, 36, Lancet 2013; 382:

10 Aberrant Early Development Duplicated Renal Collecting System Renal Aplasia Renal Fusion Disorders Multicystic Dysplastic Kidney Duplicated Renal Collecting System Duplex Kidney 2 pelvicalyceal systems Upper Pole (1/3) Lower Pole (2/3) Uncomplicated Complicated (most) Duplicated Renal Collecting System When Complicated Upper Pole Ureteral ectopia Ureterocele Lower Pole Vesicoureteral Reflux Ureteropelvic Junction Obstruction Duplicated Renal Collecting System Ureter Ectopia Most common location is bladder neck But can be anywhere in genital tract Degree of ectopia correlates with upper pole dysplasia (obstruction) J Urology 1997;158:1245 Duplicated Renal Collecting System Cyst-like Structure in Upper Pole Sagittal length of kidney > 95 th % Cyst-like structure in the upper pole Two separate renal pelves Ureterocele in the urinary bladder Dilated ureter, usually from the upper pole Ultrasound Obstet Gynecol:1996;7:

11 Duplicated Renal Collecting System Dilated Ureter Duplicated Renal Collecting System Ureterocele(s) in Bladder Duplicated Renal Collecting System Ureterocele in the bladder is often first clue to diagnosis Keep in mind that ureteroceles can collapse with full bladder Renal Aplasia, Fusion and Migration Anomalies Renal Agenesis Bilateral Unilateral Ectopic kidney Fusion disorders: Horseshoe kidney Crossed ectopia Abuhamad Ultrasound Obstet Gynecol:7;174. Bilateral Renal Agenesis Anhydramnios Empty renal fossa bilaterally Bladder cannot be visualized Doppler shows no renal arteries Flat adrenal gland Hypertrophic cardiomyopathy Bilateral Renal Agenesis Bilateral Renal Agenesis Amniotic Fluid 13 weeks 11

12 Bilateral Renal Agenesis Unilateral Renal Agenesis Flat Adrenal Flat Adrenal Prevalence 1 in 2000 births Significant association with anomalies in 30 % Contralateral vesico-urinary reflux in 20% Look for renal ectopia before final diagnosis Increase risk for hypertension later in life 12 weeks 13 weeks Unilateral Renal Agenesis Normal AFV Empty renal fossa unilaterally Normal Bladder Large normal kidney Doppler shows no renal artery on missing side Flat adrenal gland on missing side Unilateral Renal Agenesis Ultrasound Quarterly. 2010; 26(4). 233 Epidemiology 1 in 500-3,000 live births 40% of cases of empty renal fossa Most common location in pelvis, above bladder Could be any where in body Ectopic Kidney Pelvic Kidney Unilateral empty renal fossa Normal contralateral kidney Commonly, superior to the bladder May have abnormal morphology Variable blood supply Ultrasound Quarterly. 2010; 26(4) Ultrasound Quarterly. 2010; 26(4) Schematic drawing from 12

13 Pelvic Kidney Pelvic Kidney First Trimester Pelvic kidney Adrenal glands Normal kidney 74 Ectopic Kidney Thoracic Kidney Etiology Horseshoe Kidney Kidneys fuse during development Most commonly the lower poles Bridging tissue = isthmus Isthmus becomes tethered below the inferior mesenteric artery Incomplete ascent of kidneys Ultrasound Quarterly. 2010; 26(4) Schematic drawing from Horseshoe Kidney Coronal view most optimal for diagnosis Renal tissue (isthmus) over the spine Multiple renal arteries Malrotation with reversed longitudinal axis of each kidney Horseshoe Kidney J Ultrasound Med. 2000;19(1):27- UOG, 2005; 25:

14 Horseshoe Kidney Horseshoe Kidney Horseshoe Kidney Horseshoe Kidney First Trimester 14 weeks Crossed Fused Renal Ectopia Epidemiology 1 in 2,000-7,000 Associated anomalies Uterine imperforate anus skeletal Etiology Abnormal fusion Ureter of fused kidney crosses midline Inserts normally in bladder Crossed Fused Renal Ectopia Unilateral empty renal fossa Bilobed, enlarged-appearing kidney At least 2 renal arteries No renal tissue over spine on coronal view Ectopic kidney may be complicated by cystic dysplasia Ultrasound Quarterly. 2010; 26(4) Schematic drawing from Ultrasound Quarterly. 2010; 26(4) Crossed Fused Renal Ectopia Multicystic Dysplastic Kidney An abnormally functioning kidney Normal renal tissue is replaced by cysts Pathogenesis: Atresia of the uterteral bud Subsequent enlarged, noncommunicating collecting tubules forming cysts Prenatal Diagn 2001; 21: pp

15 Multicystic Dysplastic Kidney Epidemiology Unilateral: 1/4000 births Bilateral: 1/10,000 births M:F 2 : 1 Worse in females 75% Unilateral Multicystic Dysplastic Kidney Bright echogenic appearance Can be any size Multiple irregular non-communicating anechoic cysts Lack of renal pelvis Intervening parenchyma echogenic due to compression by the cysts Prenat Diagn 2001; 21: pp and Brown Medical School Digital Pathology, retrieved from: multicystic.html Prenat Diagn 2001; 21:924 Multicystic Dysplastic Kidney Small to absent renal artery with abnormal Doppler Temporal change in some Up to 35 % with extrarenal anomalies About 10% aneuploidy when associated with other anomalies Multicystic Dysplastic Kidney Approximately 25% of contralateral kidneys are abnormal Vesicoureteral reflux Ureteropelvic junction (UPJ) obstruction Ureterovesical junction (UVJ) obstruction Ectopic ureter Renal agenesis Prenat Diagn 2001; 21:924 Prenat Diagn 1999; 19: Multicystic Dysplastic Kidney Large Hyperechoic Kidneys Long-Term Outcome Majority involute over time Long term increase in hypertension and tumors Risk is low, elective nephrectomy is no longer routinely performed Long term small risk of chronic renal failure Prenat Diagn 2001; 21:924 15

16 Defects in Terminal Maturation Autosomal Recessive Polycystic Kidney Disease (ARPKD) Autosomal Dominant Polycystic Kidney Disease (ADPKD) Part of Ciliopathy group of Syndromes Polycystic Kidney Disease Key Difference Autosomal Recessive Polycystic Kidney Disease (ARPKD) Cysts originate from collecting ducts Numerous small cysts Autosomal Dominant Polycystic Kidney Disease (ADPKD) Cysts originate from all nephron Fewer larger cysts Autosomal Recessive PKD Incidence and Pathogenesis Single gene disorder 1:20,000-50,000 births M:F = 1 Mutation of PKHD1 gene-chromosome 6p12 Encode abnormal proteins, fibrocystins, causing numerous small cysts to form in the collecting tubules Autosomal Recessive PKD Ultrasound Features Enlarged hyperechoic kidneys (> 2SD) Loss of cortico-medullary differentiation Cysts undetectable by ultrasound Difficult to discern calyceal pattern Small or absent bladder Oligohydramnios Kidney echogenicity can be seen by weeks Prenatal diagnosis if informative Prenat Diagn 2001; 21:924 Autosomal Recessive PKD First Trimester Autosomal Recessive PKD Prognosis Fetus 1- ARPKD Fetus 2 - Sibling - ARPKD Variable phenotype expression Either very poor with death in neonatal period Quite reasonable if survive neonatal period Severe hypertension, Hepatic fibrosis Recurrent infections 95 16

17 Autosomal Dominant PKD Incidence and Pathogenesis 1/1000 births Mutations in the PKD-1 (85%) or PKD-2 (15%) genes (Chromosome 16) PKD-2 associated with milder disease Large cysts throughout the nephron Interstitial fibrosis Hypertension and renal failure in adulthood Autosomal Dominant PKD Ultrasound Features Enlarged echogenic kidneys Individual cysts maybe visible Calyceal system typically visible Normal bladder Normal amniotic fluid Parent with renal cysts Kidney echogenicity rarely seen before 16 weeks Prenat Diagn 2001; 21: pp Prenat Diagn 2001; 21: 924 Autosomal Dominant PKD Autosomal Dominant PKD Maternal Kidneys Autosomal Dominant PKD Prognosis Usually asymptomatic until 5 th decade Presents with HTN & end-stage renal failure Accounts for 10-15% of renal dialysis or transplant Conclusions Understand spectrum of renal abnormalities and overlap between entities New UTD classification (2014) Normal amniotic fluid > 14 weeks indicates renal function Complexity in patient counseling many renal diseases have variable expression Isolated unilateral renal anomalies are usually associated with good outcomes Bilateral renal anomalies carries guarded prognosis 17