NOTES NOTES BLADDER & URETHRAL CONGENITAL DISORDERS GENERALLY, WHAT ARE THEY? PATHOLOGY & CAUSES ▪ Congenital abnormalities in bladder, urethra ▪ Benign/kidney failure/systemic involvement CAUSES ▪ Interferences in fetal development SIGNS & SYMPTOMS DIAGNOSIS DIAGNOSTIC IMAGING Prenatal ultrasound ▪ Diagnosis difﬁcult OTHER DIAGNOSTICS ▪ Bladder exstrophy, hypospadias, epispadias: visible at birth TREATMENT ▪ May be asymptomatic until complications develop SURGERY ▪ See individual disorders BLADDER EXSTROPHY osms.it/bladder-exstrophy the mesenchymal tissue towards midline → rupture of cloacal membrane → herniation of lower abdominal components through the lower abdominal wall surface PATHOLOGY & CAUSES ▪ Congenital disorder, inside-out bladder protruding out of abdomen ▪ Part of the exstrophy-epispadias complex (EEC) that includes epispadias and cloacal exstrophy ▪ Bladder fails to fully form anteriorly, pushed through front anterior abdomen wall CAUSES ▪ Occurs during embryological development: overdevelopment of cloacal membrane disrupts development of the lower abdominal wall → prevents migration of RISK FACTORS ▪ ▪ ▪ ▪ Genetic predisposition Biological males > biological females Firstborn > subsequent births Infants born to white parents COMPLICATIONS ▪ Urinary and/or fecal incontinence, UTIs, abnormal gait, hip dysplasia, rectal prolapse; inguinal hernia, uterine prolapse OSMOSIS.ORG 769
SIGNS & SYMPTOMS ▪ Observable changes in pelvis, pelvic ﬂoor, genitalia ▫ Exposed bladder and urethra ▫ Low-set umbilicus ▫ Abnormalities of the pelvic bone, vertebral column, and spinal cord ▫ Flattened puborectal sling, anus anteriorly displaced ▫ Biological males: epispadias, absent dorsal foreskin, open prostate, shortened penis ▫ Biological females: vagina wider, shorter, more vertically oriented; displaced, narrowed vaginal oriﬁce; biﬁd clitoris; divergent labia ▫ Epispadias DIAGNOSIS DIAGNOSTIC IMAGING Figure 107.1 A newborn baby with a severe case of bladder exstrophy. The genitals are also grossly irregular. TREATMENT SURGERY ▪ Performed within ﬁrst weeks of life ▪ Staged surgeries required over months/ years CT scan ▪ CT scan detects skeletal abnormalities Ultrasound and MRI ▪ Often made by prenatal ultrasound, can be conﬁrmed by MRI OTHER DIAGNOSTICS ▪ Clinically recognizable at time of delivery Figure 107.2 Illustration of the bladder pushing through the symphysis pubis and abdominal wall during bladder exstrophy. 770 OSMOSIS.ORG
Chapter 107 Bladder & Urethral Congenital Disorders Figure 107.3 A plain pelvic radiograph demonstrating a wide symphysis pubis in a case of bladder exstrophy. HYDRONEPHROSIS osms.it/hydronephrosis PATHOLOGY & CAUSES ▪ Dilation of renal pelvis, calyces associated with kidney atrophy ▪ Severe, long-standing hydronephrosis → kidney failure ▪ Urinary tract obstruction/compression → build up of urinary pressure → progressive dilation ▪ Dilation starts at blockage, continues up towards kidneys ▫ Hydroureter: dilation of ureter ▫ Hydronephrosis/hydroureteronephrosis: dilation of ureter, renal pelvis, calyces ▪ Grading ▫ 0: no dilation ▫ I: dilation of renal pelvis ▫ II: dilation of renal pelvis, calyces ▫ III: moderate dilation of renal pelvis, calyces; mild cortical thinning, ﬂattening of papillae ▫ IV: severe renal dilation; cortical thinning CAUSES ▪ Fetus: antenatal hydronephrosis ▫ Often unknown, may disappear on own ▫ Congenital malformation: ureteropelvic junction obstruction, vesicoureteral reﬂux ▪ Children: ▫ Congenital malformation: ureterocele, posterior urethral valves ▪ Adults: ▫ Acquired disease: kidney stones (most common cause), benign prostatic hyperplasia, blood clot, contiguous malignant diseases (prostate/bladder/cervix cancer, retroperitoneal lymphoma), contiguous inﬂammation (prostatitis, ureteritis, urethritis, retroperitoneal ﬁbrosis), tissue scarring from injury/surgery, uterus enlargement during pregnancy OSMOSIS.ORG 771
MNEMONIC: SIP BaN Causes of acquired hydronephrosis Stones Inﬂammation Prostate hypertrophy Baby (pregnancy) / Blood clot Neoplasm SIGNS & SYMPTOMS TREATMENT SURGERY ▪ Restore urine ﬂow: upper blockage ▫ Acute: nephrostomy tube ▫ Chronic: ureteric stent/pyeloplasty OTHER INTERVENTIONS ▪ Restore urine ﬂow: lower blockage ▫ Urinary or suprapubic catheter ▪ Acute with sudden onset: intense pain in ﬂank, called Dietl’s crisis ▪ Nausea, vomiting DIAGNOSIS DIAGNOSTIC IMAGING Abdominal ultrasound ▪ Dilation of renal calyces ▪ Increased anteroposterior diameter ▪ Dilated ureter, if obstruction is distal Prenatal ultrasound ▪ Oligohydramnios if bilateral obstruction Intravenous (IV) urography/pyelography ▪ Demonstrates distal obstruction 772 OSMOSIS.ORG Figure 107.4 An abdominal CT scan in the coronal plane demonstrating severe hydronephrosis of the left kidney.
Chapter 107 Bladder & Urethral Congenital Disorders POSTERIOR URETHRAL VALVE osms.it/posterior-urethral-valve PATHOLOGY & CAUSES ▪ Congenital disorder, posterior urethra obstructed by membranous folds/tissue ﬂap ▪ Most common cause of bladder outlet obstruction in infants who are biologically male ▪ Obstruction increases bladder pressure → bladder wall hypertrophy → decreases bladder compliance → repeats ▪ Obstruction increases bladder pressure → ureterovesical junction dysfunction → vesicoureteral reﬂux ▪ Urine retention by obstruction → urine backs up → bilateral hydronephrosis ▪ Severe obstructions in utero → oligohydramnios → Potter syndrome ▫ Limb irregularities, facial anomalies, kidney failure, pulmonary hypoplasia Antenatal ultrasound ▪ Hydronephrosis (10% may be normal) ▪ Trabeculated and thick-walled bladder with elongation and dilation of posterior urethra ▪ Valve may be seen as echogenic line Voiding cystourethrogram (VCUG) ▪ Dilation and elongation of posterior urethra ▪ Vesicoureteral reﬂux (in half of instances) ▪ Bladder trabeculation or diverticula ▪ Radiolucent linear band (representing valve) TREATMENT SURGERY ▪ Surgical ablation of membrane ▪ Prenatal surgery CAUSES ▪ Unknown; theory: abnormal integration of Wolfﬁan duct → large plicae colliculi fuse anteriorly SIGNS & SYMPTOMS ▪ Posterior urethra obstructed by membranous folds/tissue ﬂap DIAGNOSIS DIAGNOSTIC IMAGING Prenatal ultrasound ▪ Generally seen > 26 weeks gestation ▪ Noticeable distension and hypertrophy of bladder ▪ Possitlbe hydronephrosis and hydroureter ▪ Keyhole sign: distended proximal urethra and thick-walled bladder, resembles keyhole Figure 107.5 A lateral view of a micturating cystourethrogram demonstrating a proximally dilated urethra in case of posterior urethral valve. OSMOSIS.ORG 773
VESICOURETERAL REFLUX osms.it/vesicoureteral-reflux PATHOLOGY & CAUSES ▪ Retrograde ﬂow of urine from the bladder into the ureters and kidneys ▪ Grading ▫ Grade I: urine goes into ureters ▫ Grade II: urine ﬁlls entire ureter, renal pelvis ▫ Grade III: urine ﬁlls, stretches ureter, renal pelvis ▫ Grade IV: ureter swollen, curvy; renal pelvis, calyces swollen, distorted ▫ Grade V: urine ﬁlls ureter, pelvis, calyces; swell completely ▪ Primary vesicoureteral reﬂux (most common type): due to congenital defect at ureterovesical junction (congenital absence/ shortening of intravesical portion of ureter) ▫ Inadequate closure of the ureterovesical junction → urine builds up in bladder → ureter fails to act as valve → urine returns to ureters ▪ Secondary vesicoureteral reﬂux: due to failure of the ureterovesical junction to close during bladder contraction; often due to a blockage in urinary tract ▫ Pressure increases in urinary tract → urine follows path of least resistance, back into ureters RISK FACTORS ▪ ▪ ▪ ▪ Genetic predisposition Neonates: prenatal hydronephrosis Children: febrile UTIs Individuals of white, Northern European descent COMPLICATIONS ▪ Recurrent UTIs, pyelonephritis, renal scarring/ﬁbrosis, hypertension, kidney failure ▪ Infants: asymptomatic, fever, lethargy, poor appetite 774 OSMOSIS.ORG ▪ Children: discomfort with urination; bowel and bladder dysfunction SIGNS & SYMPTOMS ▪ Infants: asymptomatic, fever, lethargy, poor apetite ▪ Children: discomfort with urination DIAGNOSIS DIAGNOSTIC IMAGING Abdominal ultrasound ▪ Assesses renal parenchyma for scarring or anatomical abnormalities ▪ Presence of hydronephrosis VCUG ▪ Should be performed on ﬁrst UTI in child < six years old ▪ Used for grading ▪ Presence of other anatomical abnormalities TREATMENT SURGERY ▪ Primary vesicoureteral reﬂux ▫ Surgery to repair valve at ureterovesical junction ▫ Infants, children: no intervention; child grows → ureters lengthens → valve function improves ▪ Secondary vesicoureteral reﬂux ▫ Surgery to remove blockage
Chapter 107 Bladder & Urethral Congenital Disorders Figure 107.6 A voiding cystourethrogram demonstrating bilateral vesicoureteric reﬂux. OSMOSIS.ORG 775