- •Preface
- •Acknowledgments
- •Contents
- •1.1 Introduction
- •1.2 Normal Embryology
- •1.3 Abnormalities of the Kidney
- •1.3.1 Renal Agenesis
- •1.3.2 Renal Hypoplasia
- •1.3.3 Supernumerary Kidneys
- •1.3.5 Polycystic Kidney Disease
- •1.3.6 Simple (Solitary) Renal Cyst
- •1.3.7 Renal Fusion and Renal Ectopia
- •1.3.8 Horseshoe Kidney
- •1.3.9 Crossed Fused Renal Ectopia
- •1.4 Abnormalities of the Ureter
- •1.5 Abnormalities of the Bladder
- •1.6 Abnormalities of the Penis and Urethra in Males
- •1.7 Abnormalities of Female External Genitalia
- •Further Reading
- •2.1 Introduction
- •2.2 Pathophysiology
- •2.3 Etiology of Hydronephrosis
- •2.5 Clinical Features
- •2.6 Investigations and Diagnosis
- •2.7 Treatment
- •2.8 Antenatal Hydronephrosis
- •Further Reading
- •3.1 Introduction
- •3.2 Embryology
- •3.3 Pathophysiology
- •3.4 Etiology of PUJ Obstruction
- •3.5 Clinical Features
- •3.6 Diagnosis and Investigations
- •3.7 Management of Newborns with PUJ Obstruction
- •3.8 Treatment
- •3.9 Post-operative Complications and Follow-Up
- •Further Reading
- •4: Renal Tumors in Children
- •4.1 Introduction
- •4.2 Wilms’ Tumor
- •4.2.1 Introduction
- •4.2.2 Etiology
- •4.2.3 Histopathology
- •4.2.4 Nephroblastomatosis
- •4.2.5 Clinical Features
- •4.2.6 Risk Factors for Wilms’ Tumor
- •4.2.7 Staging of Wilms Tumor
- •4.2.8 Investigations
- •4.2.9 Prognosis and Complications of Wilms Tumor
- •4.2.10 Surgical Considerations
- •4.2.11 Surgical Complications
- •4.2.12 Prognosis and Outcome
- •4.2.13 Extrarenal Wilms’ Tumors
- •4.3 Mesoblastic Nephroma
- •4.3.1 Introduction
- •4.3.3 Epidemiology
- •4.3.5 Clinical Features
- •4.3.6 Investigations
- •4.3.7 Treatment and Prognosis
- •4.4 Clear Cell Sarcoma of the Kidney (CCSK)
- •4.4.1 Introduction
- •4.4.2 Pathophysiology
- •4.4.3 Clinical Features
- •4.4.4 Investigations
- •4.4.5 Histopathology
- •4.4.6 Treatment
- •4.4.7 Prognosis
- •4.5 Malignant Rhabdoid Tumor of the Kidney
- •4.5.1 Introduction
- •4.5.2 Etiology and Pathophysiology
- •4.5.3 Histologic Findings
- •4.5.4 Clinical Features
- •4.5.5 Investigations and Diagnosis
- •4.5.6 Treatment and Outcome
- •4.5.7 Mortality/Morbidity
- •4.6 Renal Cell Carcinoma in Children
- •4.6.1 Introduction
- •4.6.2 Histopathology
- •4.6.4 Staging
- •4.6.5 Clinical Features
- •4.6.6 Investigations
- •4.6.7 Management
- •4.6.8 Prognosis
- •4.7 Angiomyolipoma of the Kidney
- •4.7.1 Introduction
- •4.7.2 Histopathology
- •4.7.4 Clinical Features
- •4.7.5 Investigations
- •4.7.6 Treatment and Prognosis
- •4.8 Renal Lymphoma
- •4.8.1 Introduction
- •4.8.2 Etiology and Pathogenesis
- •4.8.3 Diagnosis
- •4.8.4 Clinical Features
- •4.8.5 Treatment and Prognosis
- •4.9 Ossifying Renal Tumor of Infancy
- •4.10 Metanephric Adenoma
- •4.10.1 Introduction
- •4.10.2 Histopathology
- •4.10.3 Diagnosis
- •4.10.4 Clinical Features
- •4.10.5 Treatment
- •4.11 Multilocular Cystic Renal Tumor
- •Further Reading
- •Wilms’ Tumor
- •Mesoblastic Nephroma
- •Renal Cell Carcinoma in Children
- •Angiomyolipoma of the Kidney
- •Renal Lymphoma
- •Ossifying Renal Tumor of Infancy
- •Metanephric Adenoma
- •Multilocular Cystic Renal Tumor
- •5.1 Introduction
- •5.2 Embryology
- •5.4 Histologic Findings
- •5.7 Associated Anomalies
- •5.8 Clinical Features
- •5.9 Investigations
- •5.10 Treatment
- •Further Reading
- •6: Congenital Ureteral Anomalies
- •6.1 Etiology
- •6.2 Clinical Features
- •6.3 Investigations and Diagnosis
- •6.4 Duplex (Duplicated) System
- •6.4.1 Introduction
- •6.4.3 Clinical Features
- •6.4.4 Investigations
- •6.4.5 Treatment and Prognosis
- •6.5 Ectopic Ureter
- •6.5.1 Introduction
- •6.5.3 Clinical Features
- •6.5.4 Diagnosis
- •6.5.5 Surgical Treatment
- •6.6 Ureterocele
- •6.6.1 Introduction
- •6.6.3 Clinical Features
- •6.6.4 Investigations and Diagnosis
- •6.6.5 Treatment
- •6.6.5.1 Surgical Interventions
- •6.8 Mega Ureter
- •Further Reading
- •7: Congenital Megaureter
- •7.1 Introduction
- •7.3 Etiology and Pathophysiology
- •7.4 Clinical Presentation
- •7.5 Investigations and Diagnosis
- •7.6 Treatment and Prognosis
- •7.7 Complications
- •Further Reading
- •8.1 Introduction
- •8.2 Pathophysiology
- •8.4 Etiology of VUR
- •8.5 Clinical Features
- •8.6 Investigations
- •8.7 Management
- •8.7.1 Medical Treatment of VUR
- •8.7.2 Antibiotics Used for Prophylaxis
- •8.7.3 Anticholinergics
- •8.7.4 Surveillance
- •8.8 Surgical Therapy of VUR
- •8.8.1 Indications for Surgical Interventions
- •8.8.2 Indications for Surgical Interventions Based on Age at Diagnosis and the Presence or Absence of Renal Lesions
- •8.8.3 Endoscopic Injection
- •8.8.4 Surgical Management
- •8.9 Mortality/Morbidity
- •Further Reading
- •9: Pediatric Urolithiasis
- •9.1 Introduction
- •9.2 Etiology
- •9.4 Clinical Features
- •9.5 Investigations
- •9.6 Complications of Urolithiasis
- •9.7 Management
- •Further Reading
- •10.1 Introduction
- •10.2 Embryology of Persistent Müllerian Duct Syndrome
- •10.3 Etiology and Inheritance of PMDS
- •10.5 Clinical Features
- •10.6 Treatment
- •10.7 Prognosis
- •Further Reading
- •11.1 Introduction
- •11.2 Physiology and Bladder Function
- •11.2.1 Micturition
- •11.3 Pathophysiological Changes of NBSD
- •11.4 Etiology and Clinical Features
- •11.5 Investigations and Diagnosis
- •11.7 Management
- •11.8 Clean Intermittent Catheterization
- •11.9 Anticholinergics
- •11.10 Botulinum Toxin Type A
- •11.11 Tricyclic Antidepressant Drugs
- •11.12 Surgical Management
- •Further Reading
- •12.1 Introduction
- •12.2 Etiology
- •12.3 Pathophysiology
- •12.4 Clinical Features
- •12.5 Investigations and Diagnosis
- •12.6 Management
- •Further Reading
- •13.1 Introduction
- •13.2 Embryology
- •13.3 Epispadias
- •13.3.1 Introduction
- •13.3.2 Etiology
- •13.3.4 Treatment
- •13.3.6 Female Epispadias
- •13.3.7 Surgical Repair of Female Epispadias
- •13.3.8 Prognosis
- •13.4 Bladder Exstrophy
- •13.4.1 Introduction
- •13.4.2 Associated Anomalies
- •13.4.3 Principles of Surgical Management of Bladder Exstrophy
- •13.4.4 Evaluation and Management
- •13.5 Cloacal Exstrophy
- •13.5.1 Introduction
- •13.5.2 Skeletal Changes in Cloacal Exstrophy
- •13.5.3 Etiology and Pathogenesis
- •13.5.4 Prenatal Diagnosis
- •13.5.5 Associated Anomalies
- •13.5.8 Surgical Reconstruction
- •13.5.9 Management of Urinary Incontinence
- •13.5.10 Prognosis
- •13.5.11 Complications
- •Further Reading
- •14.1 Introduction
- •14.2 Etiology
- •14.3 Clinical Features
- •14.4 Associated Anomalies
- •14.5 Diagnosis
- •14.6 Treatment and Prognosis
- •Further Reading
- •15: Cloacal Anomalies
- •15.1 Introduction
- •15.2 Associated Anomalies
- •15.4 Clinical Features
- •15.5 Investigations
- •Further Reading
- •16: Urachal Remnants
- •16.1 Introduction
- •16.2 Embryology
- •16.4 Clinical Features
- •16.5 Tumors and Urachal Remnants
- •16.6 Management
- •Further Reading
- •17: Inguinal Hernias and Hydroceles
- •17.1 Introduction
- •17.2 Inguinal Hernia
- •17.2.1 Incidence
- •17.2.2 Etiology
- •17.2.3 Clinical Features
- •17.2.4 Variants of Hernia
- •17.2.6 Treatment
- •17.2.7 Complications of Inguinal Herniotomy
- •17.3 Hydrocele
- •17.3.1 Embryology
- •17.3.3 Treatment
- •Further Reading
- •18: Cloacal Exstrophy
- •18.1 Introduction
- •18.2 Etiology and Pathogenesis
- •18.3 Associated Anomalies
- •18.4 Clinical Features and Management
- •Further Reading
- •19: Posterior Urethral Valve
- •19.1 Introduction
- •19.2 Embryology
- •19.3 Pathophysiology
- •19.5 Clinical Features
- •19.6 Investigations and Diagnosis
- •19.7 Management
- •19.8 Medications Used in Patients with PUV
- •19.10 Long-Term Outcomes
- •19.10.3 Bladder Dysfunction
- •19.10.4 Renal Transplantation
- •19.10.5 Fertility
- •Further Reading
- •20.1 Introduction
- •20.2 Embryology
- •20.4 Clinical Features
- •20.5 Investigations
- •20.6 Treatment
- •20.7 The Müllerian Duct Cyst
- •Further Reading
- •21: Hypospadias
- •21.1 Introduction
- •21.2 Effects of Hypospadias
- •21.3 Embryology
- •21.4 Etiology of Hypospadias
- •21.5 Associated Anomalies
- •21.7 Clinical Features of Hypospadias
- •21.8 Treatment
- •21.9 Urinary Diversion
- •21.10 Postoperative Complications
- •Further Reading
- •22: Male Circumcision
- •22.1 Introduction
- •22.2 Anatomy and Pathophysiology
- •22.3 History of Circumcision
- •22.4 Pain Management
- •22.5 Indications for Circumcision
- •22.6 Contraindications to Circumcision
- •22.7 Surgical Procedure
- •22.8 Complications of Circumcision
- •Further Reading
- •23: Priapism in Children
- •23.1 Introduction
- •23.2 Pathophysiology
- •23.3 Etiology
- •23.5 Clinical Features
- •23.6 Investigations
- •23.7 Management
- •23.8 Prognosis
- •23.9 Priapism and Sickle Cell Disease
- •23.9.1 Introduction
- •23.9.2 Epidemiology
- •23.9.4 Pathophysiology
- •23.9.5 Clinical Features
- •23.9.6 Treatment
- •23.9.7 Prevention of Stuttering Priapism
- •23.9.8 Complications of Priapism and Prognosis
- •Further Reading
- •24.1 Introduction
- •24.2 Embryology and Normal Testicular Development and Descent
- •24.4 Causes of Undescended Testes and Risk Factors
- •24.5 Histopathology
- •24.7 Clinical Features and Diagnosis
- •24.8 Treatment
- •24.8.1 Success of Surgical Treatment
- •24.9 Complications of Orchidopexy
- •24.10 Infertility and Undescended Testes
- •24.11 Undescended Testes and the Risk of Cancer
- •Further Reading
- •25: Varicocele
- •25.1 Introduction
- •25.2 Etiology
- •25.3 Pathophysiology
- •25.4 Grading of Varicoceles
- •25.5 Clinical Features
- •25.6 Diagnosis
- •25.7 Treatment
- •25.8 Postoperative Complications
- •25.9 Prognosis
- •Further Reading
- •26.1 Introduction
- •26.2 Etiology and Risk Factors
- •26.3 Diagnosis
- •26.4 Intermittent Testicular Torsion
- •26.6 Effects of Testicular Torsion
- •26.7 Clinical Features
- •26.8 Treatment
- •26.9.1 Introduction
- •26.9.2 Etiology of Extravaginal Torsion
- •26.9.3 Clinical Features
- •26.9.4 Treatment
- •26.10 Torsion of the Testicular or Epididymal Appendage
- •26.10.1 Introduction
- •26.10.2 Embryology
- •26.10.3 Clinical Features
- •26.10.4 Investigations and Treatment
- •Further Reading
- •27: Testicular Tumors in Children
- •27.1 Introduction
- •27.4 Etiology of Testicular Tumors
- •27.5 Clinical Features
- •27.6 Staging
- •27.6.1 Regional Lymph Node Staging
- •27.7 Investigations
- •27.8 Treatment
- •27.9 Yolk Sac Tumor
- •27.10 Teratoma
- •27.11 Mixed Germ Cell Tumor
- •27.12 Stromal Tumors
- •27.13 Simple Testicular Cyst
- •27.14 Epidermoid Cysts
- •27.15 Testicular Microlithiasis (TM)
- •27.16 Gonadoblastoma
- •27.17 Cystic Dysplasia of the Testes
- •27.18 Leukemia and Lymphoma
- •27.19 Paratesticular Rhabdomyosarcoma
- •27.20 Prognosis and Outcome
- •Further Reading
- •28: Splenogonadal Fusion
- •28.1 Introduction
- •28.2 Etiology
- •28.4 Associated Anomalies
- •28.5 Clinical Features
- •28.6 Investigations
- •28.7 Treatment
- •Further Reading
- •29: Acute Scrotum
- •29.1 Introduction
- •29.2 Torsion of Testes
- •29.2.1 Introduction
- •29.2.3 Etiology
- •29.2.4 Clinical Features
- •29.2.5 Effects of Torsion of Testes
- •29.2.6 Investigations
- •29.2.7 Treatment
- •29.3 Torsion of the Testicular or Epididymal Appendage
- •29.3.1 Introduction
- •29.3.2 Embryology
- •29.3.3 Clinical Features
- •29.3.4 Investigations and Treatment
- •29.4.1 Introduction
- •29.4.2 Etiology
- •29.4.3 Clinical Features
- •29.4.4 Investigations and Treatment
- •29.5 Idiopathic Scrotal Edema
- •29.6 Testicular Trauma
- •29.7 Other Causes of Acute Scrotum
- •29.8 Splenogonadal Fusion
- •Further Reading
- •30.1 Introduction
- •30.2 Imperforate Hymen
- •30.3 Vaginal Atresia
- •30.5 Associated Anomalies
- •30.6 Embryology
- •30.7 Clinical Features
- •30.8 Investigations
- •30.9 Management
- •Further Reading
- •31: Disorders of Sexual Development
- •31.1 Introduction
- •31.2 Embryology
- •31.3 Sexual and Gonadal Differentiation
- •31.5 Evaluation of a Newborn with DSD
- •31.6 Diagnosis and Investigations
- •31.7 Management of Patients with DSD
- •31.8 Surgical Corrections of DSD
- •31.9 Congenital Adrenal Hyperplasia (CAH)
- •31.10 Androgen Insensitivity Syndrome (Testicular Feminization Syndrome)
- •31.13 Gonadal Dysgenesis
- •31.15 Ovotestis Disorders of Sexual Development
- •31.16 Other Rare Disorders of Sexual Development
- •Further Reading
- •Index
6.4 Duplex (Duplicated) System |
189 |
|
|
•Renal and bladder ultrasound:
–This is a first-line imaging study to evaluate the upper and lower urinary tract.
–Ultrasound evaluation of upper urinary tract anomalies include ureteral duplication, dilatation of collecting system, character and thickness of the renal parenchyma.
–Ultrasound evaluation of lower urinary tract anomalies include bladder wall thickness, ureterocele, bladder diverticulum, posterior urethral dilatation, and degree of bladder emptying.
•Voiding cystourethrogram (VCUG):
–This is valuable for evaluation of the bladder and urethra.
–This includes evaluation of:
•VUR
•Bladder diverticulum
•Ureterocele
•Bladder trabeculations and bladder emptying
•Urethral anatomy during voiding
•The ureters if VUR is present
•Diuretic nuclear renography:
–This is an excellent study to evaluate:
•The differential renal function
•Cortical scars
•Drainage efficiency of the dilated collecting system based on washout times
•Intravenous pyelogram (IVP):
–This study has been largely replaced by ultrasound and nuclear renography.
–IVP delineates anatomy of the kidney, collecting system, ureter and urinary bladder.
–It also provides subjective estimation of relative renal function.
•MR urography (MRU):
–This provides excellent anatomic and functional evaluation of the renal parenchyma, collecting system and vasculature without exposure to radiation.
–MRU is sensitive to motion artifact and necessitates anesthetic sedation of young children.
•Urodynamic studies:
–This is valuable to assess voiding and bladder function in those with suspected neurogenic bladder.
•Cystoscopy, vaginoscopy, and retrograde pyelogram are endoscopic procedures that allow direct visualization of the genital and lower urinary tracts and may include radiographic visualization of the upper urinary tract (e.g. retrograde pyelogram).
•Pressure-perfusion studies (Whitaker test):
–This measure differential pressures of the renal pelvis and the bladder
–It may be useful in evaluating equivocal urinary tract obstruction
–It is invasive and depends on percutaneous placement of a catheter
–It is seldom used in the modern era of nuclear renography
6.4Duplex (Duplicated) System
6.4.1Introduction
•A duplex collecting system is one of the most common congenital urinary tract abnormalities.
•It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a variety of complete or incomplete duplications of the collecting system.
•A duplex (duplicated) collecting systems can be defined as renal units containing two pyelocaliceal systems that are associated with a single ureter or with double ureters.
•The two ureters empty separately into the bladder or fuse to form a single ureteral orifice.
•Duplex collecting systems can be unilateral or bilateral and can be associated with a variety of congenital genitourinary tract abnormalities (Figs. 6.2, 6.3, 6.4, 6.5, 6.6, and 6.7).
•The exact incidence of ureteral duplication is not known but an incidence as high as 8 % in children was reported.
–Incomplete ureteral duplication was reported in approximately 1 in 25 individuals (Figs. 6.8, 6.9, 6.10, and 6.11).
–Complete ureteral duplication was reported in approximately 1 in 125 individuals (Figs. 6.12 and 6.13).
190 |
6 Congenital Ureteral Anomalies |
|
|
Figs. 6.2, 6.3, 6.4, 6.5, 6.6, and 6.7 Intravenous urography and CT urography showing duplex ureters. In the intravenous urography pictures, each ureter is draing one renal unit. There is an associated hydronephrosis in the
upper renal unit. The lower renal unit is normal. Note also on the CT urography the associated hydronephrosis and hydroureters in the lower renal unit while the upper renal unit is normal
6.4 Duplex (Duplicated) System |
191 |
|
|
INCOMPLETE OR
PARTIAL URETERAL
DUPLICATION
Figs. 6.8, 6.9, 6.10, and 6.11 Clinical intraoperative photographs showing duplex ureters. Note the complete and partial ureteral duplications
Figs. 6.12 and 6.13 Clinical intraoperative photographs showing complete ureteral duplication. Note the associated dysplastic kidney
• In patients with complete duplication on one |
– Complete duplication where the two ure- |
|
side, there is a 40 % chance of finding com- |
ters empty separately into the urinary |
|
plete duplication on the other side. |
bladder. |
|
• Approximately 10 % of siblings may also be |
• |
The upper ureter is more likely to be |
affected by complete duplication. |
|
associated with ectopic insertion, ure- |
• Duplex collecting systems are seen in 0.7% of |
|
terocele, and/or obstruction. |
the normal adult population and in 2–4% of |
• Caudal or medial ectopia describes the |
|
patients investigated for urinary tract symptoms. |
|
ureteral orifice when located at the |
• The duplicated ureters can be: |
|
proximal lip of the bladder neck or more |
– Bifid ureters (partial or incomplete |
|
distal. |
duplication) |
• |
The lower ureter is more frequently |
• The two ureters fuse together and insert |
|
associated with VUR. |
distally as a single ureter into the uri- |
• The upper pole is one of the components |
|
nary bladder. |
|
of the duplex kidney. |
192 |
6 Congenital Ureteral Anomalies |
|
|
•The upper pole ureter drains the upper pole of a duplex kidney.
•Similarly, the lower pole of the kidney is drained by the lower-pole ureter.
•Most patients are asymptomatic, with urinary tract abnormalities being detected incidentally on imaging studies performed for other reasons.
•These anomalies are commonly asymptomatic and considered an anatomical variant.
•Ureteropelvic obstruction is more common when a duplex kidney exists and can be inherited in an autosomal dominant pattern.
•Congenital renal anomalies in patients with classic bladder exstrophy occur in 2.8 % of patients.
•The most common anomaly is a duplicated collecting system, which occurs in approximately 1.3 % of patients.
•Duplex collecting systems may be complicated by:
–Vesicoureteral reflux
–Obstruction
–Ureterocoele
•Each of these complications may have adverse effects on the ipsilateral kidney.
•A patient’s duplex kidney is almost always more elongated than his/her nonduplex kidney.
•The kidney may be enlarged when hydronephrotic and can be associated with rotational anomalies.
•Magnetic resonance urography (MRU) may be used as the primary diagnostic method for assessing a duplex ectopic ureter, as well as the complications associated with duplex kidneys.
•If vesico-ureteral reflux exists, the presence of an ectopic ureter in a nonfunctioning moiety can best be demonstrated using a voiding cystourethrogram.
•Antegrade pyelography is useful in patients with hydronephrosis, to demonstrate the presence of a second ureter and to determine the level of ureteric termination.
•Computed tomography (CT) scanning with contrast is valuable in the evaluation of an intravesical ureterocele, either orthotopic or ectopic.
•Scintigraphy is useful in the assessment of relative renal function and in the detection of renal scars. Scintigraphy can reveal differential functioning. However, if the functioning is markedly depressed, imaging is limited.
•In the absence of obstruction and/or VUR, ureteral duplication anomalies require no specific therapy.
•Symptomatic patients usually have complete ureteric duplication in which the ureters are prone to develop obstruction, reflux, and infection.
•Duplication anomalies with associated pathology, such as VUR or obstruction, require appropriate medical therapy and possible surgical correction.
6.4.2Classification
•Duplex collecting system or duplex kidney anomalies can be classified into the following categories depending on the level or lack of fusion:
–Duplex kidney:
•The duplex kidney has a single renal parenchyma that is drained by two separate pelvicalcyeal systems
–Duplex collecting system: The kidney has two pyelocaliceal systems and is associated with a single ureter or with a bifid ureter (a partial duplication) or, in the case of a complete duplication, with two ureters (double ureters) that drain separately into the urinary bladder.
–So, a duplex collecting system is a duplex kidney draining into:
•Single ureter: Duplex kidneys and duplication pelvicalyceal systems uniting at the pelviureteric junction (PUJ)
•Bifid ureter (ureter fissus): two ureters that unite before emptying into the bladder
•Double ureter (complete duplication)
–Bifid collecting system:
•This refers to a duplex kidney with the two separate pelvicalyceal collecting systems uniting at the PUJ or as bifid ureters.