- •Preface and Acknowledgments
- •Contents
- •Contributors
- •1: Embryology for Urologists
- •Introduction
- •Renal Development
- •Pronephros
- •Mesonephros
- •Metanephros
- •Development of the Collecting System
- •Critical Steps in Further Development
- •Anomalies of the Kidney
- •Renal Agenesis
- •Renal Aplasia
- •Renal Hypoplasia
- •Renal Ectopia
- •Renal Fusion
- •Ureteral Development
- •Anomalies of Origin
- •Anomalies of Number
- •Incomplete Ureteral Duplication
- •Complete Ureteral Duplication
- •Ureteral Ectopia
- •Embryology of Ectopia
- •Clinical Correlation
- •Location of Ectopic Ureteral Orifices – Male (in Descending Order According to Incidence)
- •Symptoms
- •Ureteroceles
- •Congenital Ureteral Obstruction
- •Pipestem Ureter
- •Megaureter-Megacystis Syndrome
- •Prune Belly Syndrome
- •Vascular Ureteral Obstructions
- •Division of the Urogenital Sinus
- •Bladder Development
- •Urachal Anomalies
- •Cloacal Duct Anomalies
- •Other Bladder Anomalies
- •Bladder Diverticula
- •Bladder Extrophy
- •Gonadal Development
- •Testicular Differentiation
- •Ovarian Differentiation
- •Gonadal Anomalies
- •Genital Duct System
- •Disorders of Testicular Function
- •Female Ductal Development
- •Prostatic Urethral Valves
- •Gonadal Duct Anomalies
- •External Genital Development
- •Male External Genital Development
- •Female External Genital Development
- •Anomalies of the External Genitalia
- •References
- •2: Gross and Laparoscopic Anatomy of the Upper Urinary Tract and Retroperitoneum
- •Overview
- •The Kidneys
- •The Renal Vasculature
- •The Renal Collecting System
- •The Ureters
- •Retroperitoneal Lymphatics
- •Retroperitoneal Nerves
- •The Adrenal Glands
- •References
- •3: Gross and Laparoscopic Anatomy of the Lower Urinary Tract and Pelvis
- •Introduction
- •Female Pelvis
- •Male Pelvis
- •Pelvic Floor
- •Urinary Bladder
- •Urethra
- •Male Urethra
- •Female Urethra
- •Sphincter Mechanisms
- •The Bladder Neck Component
- •The Urethral Wall Component
- •The External Urethral Sphincter
- •Summary
- •References
- •4: Anatomy of the Male Reproductive System
- •Testis and Scrotum
- •Spermatogenesis
- •Hormonal Regulation of Spermatogenesis
- •Genetic Regulation of Spermatogenesis
- •Epididymis and Ductus Deferens
- •Accessory Sex Glands
- •Prostate
- •Seminal Vesicles
- •Bulbourethral Glands
- •Penis
- •Erection and Ejaculation
- •References
- •5: Imaging of the Upper Tracts
- •Anatomy of the Upper Tracts and Introduction to Imaging Modalities
- •Introduction
- •Renal Upper Tract Basic Anatomy
- •Modalities Used for Imaging the Upper Tracts
- •Ultrasound
- •Radiation Issues
- •Contrast Issues
- •Renal and Upper Tract Tumors
- •Benign Renal Tumors
- •Transitional Cell Carcinoma
- •Renal Mass Biopsy
- •Renal Stone Disease
- •Ultrasound
- •Plain Radiographs and IVU
- •Renal Cystic Disease
- •Benign Renal Cysts
- •Hereditary Renal Cystic Disease
- •Complex Renal Cysts
- •Renal Trauma
- •References
- •Introduction
- •Pathophysiology
- •Susceptibility and Resistance
- •Epidemiological Breakpoints
- •Clinical Breakpoints
- •Pharmacodynamic Parameters
- •Pharmacokinetic Parameters
- •Fosfomycin
- •Nitrofurantoin
- •Pivmecillinam
- •b-Lactam-Antibiotics
- •Penicillins
- •Cephalosporins
- •Carbapenems
- •Aminoglycosides
- •Fluoroquinolones
- •Trimethoprim, Cotrimoxazole
- •Glycopeptides
- •Linezolid
- •Conclusion
- •References
- •7: An Overview of Renal Physiology
- •Introduction
- •Body Fluid Compartments
- •Regulation of Potassium Balance
- •Regulation of Acid–Base Balance
- •Diuretics
- •Suggested Reading
- •8: Ureteral Physiology and Pharmacology
- •Ureteral Anatomy
- •Modulation of Peristalsis
- •Ureteral Pharmacology
- •Conclusion
- •References
- •Introduction
- •Afferent Signaling Pathways
- •Efferent Signaling
- •Parasympathetic Nerves
- •Sympathetic Nerves
- •Vesico-Spinal-Vesical Micturition Reflex
- •Peripheral Targets
- •Afferent Signaling Mechanisms
- •Urothelium
- •Myocytes
- •Cholinergic Receptors
- •Muscarinic Receptors
- •Nicotinic Receptors
- •Adrenergic Receptors (ARs)
- •a-Adrenoceptors
- •b-Adrenoceptors
- •Transient Receptor Potential (TRP) Receptors
- •Phosphodiesterases (PDEs)
- •CNS Targets
- •Opioid Receptors
- •Serotonin (5-HT) Mechanisms
- •g-Amino Butyric Acid (GABA) Mechanisms
- •Gabapentin
- •Neurokinin and Neurokinin Receptors
- •Summary
- •References
- •10: Pharmacology of Sexual Function
- •Introduction
- •Sexual Desire/Arousal
- •Endocrinology
- •Steroids in the Male
- •Steroids in the Female
- •Neurohormones
- •Neurotransmitters
- •Dopamine
- •Serotonin
- •Pharmacological Strategies
- •CNS Drugs
- •Enzyme-inducing Antiepileptic Drugs
- •Erectile Function
- •Ejaculatory Function
- •Premature Ejaculation
- •Abnormal Ejaculation
- •Conclusions
- •References
- •Epidemiology
- •Calcium-Based Urolithiasis
- •Uric Acid Urolithiasis
- •Infectious Urolithiasis
- •Cystine-Based Urolithiasis
- •Aims
- •Who Deserves Metabolic Evaluation?
- •Metabolic Workup for Stone Producers
- •Medical History and Physical Examination
- •Stone Analysis
- •Serum Chemistry
- •Urine Evaluation
- •Urine Cultures
- •Urinalysis
- •Twenty-Four Hour Urine Collections
- •Radiologic Imaging
- •Medical Management
- •Conservative Management
- •Increased Fluid Intake
- •Citrus Juices
- •Dietary Restrictions
- •Restricted Oxalate Diet
- •Conservative Measures
- •Selective Medical Therapy
- •Absorptive Hypercalciuria
- •Thiazide
- •Orthophosphate
- •Renal Hypercalciuria
- •Primary Hyperparathyroidism
- •Hyperuricosuric Calcium Oxalate Nephrolithiasis
- •Enteric Hyperoxaluria
- •Hypocitraturic Calcium Oxalate Nephrolithiasis
- •Distal Renal Tubular Acidosis
- •Chronic Diarrheal States
- •Thiazide-Induced Hypocitraturia
- •Idiopathic Hypocitraturic Calcium Oxalate Nephrolithiasis
- •Hypomagnesiuric Calcium Nephrolithiasis
- •Gouty Diathesis
- •Cystinuria
- •Infection Lithiasis
- •Summary
- •References
- •12: Molecular Biology for Urologists
- •Introduction
- •Inherited Changes in Cancer Cells
- •VEGR and Cell Signaling
- •Targeting mTOR
- •Conclusion
- •References
- •13: Chemotherapeutic Agents for Urologic Oncology
- •Introduction
- •Bladder Cancer
- •Muscle Invasive Bladder Cancer
- •Metastatic Bladder Cancer
- •Conclusion
- •Prostate Cancer
- •Other Chemotherapeutic Drugs or Combinations for Treating HRPC
- •Conclusion
- •Renal Cell Carcinoma
- •Chemotherapy
- •Immunotherapy
- •Angiogenesis Inhibitor Drugs
- •Conclusion
- •Testicular Cancer
- •Stage I Seminoma
- •Stage I non-seminomatous Germ Cell Tumours (NSGCT)
- •Metastatic Germ Cell Tumours
- •Low-Volume Metastatic Disease (Stage II A/B)
- •Advanced Metastatic Disease
- •Salvage Chemotherapy for Relapsed or Refractory Disease
- •Conclusion
- •Penile Cancer
- •Side Effects of Chemotherapy
- •Conclusion
- •References
- •14: Tumor and Transplant Immunology
- •Antibodies
- •Cytotoxic and T-helper Cells
- •Immunosuppression
- •Induction Therapy
- •Maintenance Therapy
- •Rejection
- •Posttransplant Lymphoproliferative Disease
- •Summary
- •References
- •15: Pathophysiology of Renal Obstruction
- •Causes of Renal Obstruction
- •Effects on Prenatal Development
- •Prenatal Hydronephrosis
- •Spectrum of Renal Abnormalities
- •Renal Functional Changes
- •Renal Growth/Counterbalance
- •Vascular Changes
- •Inflammatory Mediators
- •Glomerular Development Changes
- •Mechanical Stretch of Renal Tubules
- •Unilateral Versus Bilateral
- •Limitations of Animal Models
- •Future Research
- •Issues in Patient Management
- •Diagnostic Imaging
- •Ultrasound
- •Intravenous Urography
- •Antegrade Urography and the Whitaker Test
- •Nuclear Renography
- •Computed Tomography
- •Magnetic Resonance Urography
- •Hypertension
- •Postobstructive Diuresis
- •References
- •Introduction
- •The Normal Lower Urinary Tract
- •Anatomy
- •Storage Function
- •Voiding Function
- •Neural Control
- •Symptoms
- •Flow Rate and Post-void Residual
- •Voiding Cystometry
- •Male
- •Female
- •Neurourology
- •Conclusions
- •References
- •17: Urologic Endocrinology
- •The Testis
- •Normal Androgen Metabolism
- •Epidemiological Aspects
- •Prostate
- •Brain
- •Muscle Mass and Adipose Tissue
- •Bones
- •Ematopoiesis
- •Metabolism
- •Cardiovascular System
- •Clinical Assessment
- •Biochemical Assessment
- •Treatment Modalities
- •Oral Preparations
- •Parenteral Preparations
- •Transdermal Preparations
- •Side Effects and Treatment Monitoring
- •Body Composition
- •Cognitive Decline
- •Bone Metabolism
- •The Kidneys
- •Endocrine Functions of the Kidney
- •Erythropoietin
- •Calcitriol
- •Renin
- •Paraneoplastic Syndromes
- •Hypercalcemia
- •Hypertension
- •Polycythemia
- •Other Endocrine Abnormalities
- •References
- •General Physiology
- •Prostate Innervation
- •Summary
- •References
- •Wound Healing
- •Inflammation
- •Proliferation
- •Remodeling
- •Principles of Plastic Surgery
- •Tissue Characteristics
- •Grafts
- •Flap
- •References
- •Lower Urinary Tract Symptoms
- •Storage Phase
- •Voiding Phase
- •Return to Storage Phase
- •Urodynamic Parameters
- •Urodynamic Techniques
- •Volume Voided Charts
- •Pad Testing
- •Typical Test Schedule
- •Uroflowmetry
- •Post Voiding Residual
- •Further Diagnostic Evaluation of Patients
- •Cystometry with or Without Video
- •Cystometry
- •Videocystometrography (Cystometry + Cystourethrography)
- •Cystometric Findings
- •Comment:
- •Measurements During the Storage Phase:
- •Measurements During the Voiding Phase:
- •Abnormal Function
- •Disorders of Sensation
- •Causes of Hypersensitive Bladder Sensation
- •Causes of Hyposensitive Bladder Sensation
- •Disorders of Detrusor Motor Function
- •Bladder Outflow Tract Dysfunction
- •Detrusor–Urethral Dyssynergia
- •Detrusor–Bladder Neck Dyssynergia
- •Detrusor–Sphincter Dyssynergia
- •Complex Urodynamic Investigation
- •Urethral Pressure Measurement
- •Technique
- •Neurophysiological Evaluation
- •Conclusion
- •References
- •Endoscopy
- •Cystourethroscopy
- •Ureteroscopy and Ureteropyeloscopy
- •Nephroscopy
- •Virtual Reality Simulators
- •Lasers
- •Clinical Application of Lasers
- •Condylomata Acuminata
- •Urolithiasis
- •Benign Prostatic Hyperplasia
- •Ureteral and Urethral Strictures
- •Conclusion
- •References
- •Introduction
- •The Prostatitis Syndromes
- •The Scope of the Problem
- •Category III CP/CPPS
- •The Goal of Treatment
- •Conservative Management
- •Drug Therapy
- •Antibiotics
- •Anti-inflammatories
- •Alpha blockers
- •Hormone Therapies
- •Phytotherapies
- •Analgesics, muscle relaxants and neuromodulators
- •Surgery
- •A Practical Management Plan
- •References
- •Orchitis
- •Definition and Etiology
- •Clinical Signs and Symptoms
- •Diagnostic Evaluation
- •Treatment of Infectious Orchitis
- •Epididymitis
- •Definition and Etiology
- •Clinical Signs and Symptoms
- •Diagnostic Evaluation of Epididymitis
- •Treatment of Acute Epididymitis
- •Treatment of Chronic Epididymitis
- •Treatment of Spermatic Cord Torsion
- •Fournier’s Gangrene
- •Definition and Etiology
- •Risk Factors
- •Clinical Signs and Symptoms
- •Diagnostic Evaluation
- •Treatment
- •References
- •Fungal Infections
- •Candidiasis
- •Aspergillosis
- •Cryptococcosis
- •Blastomycosis
- •Coccidioidomycosis
- •Histoplasmosis
- •Radiographic Findings
- •Treatment
- •Tuberculosis
- •Clinical Manifestations
- •Diagnosis
- •Treatment
- •Schistosomiasis
- •Clinical Manifestations
- •Diagnosis
- •Treatment
- •Filariasis
- •Clinical Manifestations
- •Diagnosis
- •Treatment
- •Onchocerciasis
- •References
- •25: Sexually Transmitted Infections
- •Introduction
- •STIs Associated with Genital Ulcers
- •Herpes Simplex Virus
- •Diagnosis
- •Treatment
- •Chancroid
- •Diagnosis
- •Treatment
- •Syphilis
- •Diagnosis
- •Treatment
- •Lymphogranuloma Venereum
- •Diagnosis
- •Treatment
- •Chlamydia
- •Diagnosis
- •Treatment
- •Gonorrhea
- •Diagnosis
- •Treatment
- •Trichomoniasis
- •Diagnosis
- •Treatment
- •Human Papilloma Virus
- •Diagnosis
- •Treatment
- •Scabies
- •Diagnosis
- •Treatment
- •References
- •26: Hematuria: Evaluation and Management
- •Introduction
- •Classification of Hematuria
- •Macroscopic Hematuria
- •Microscopic Hematuria
- •Dipstick Hematuria
- •Pseudohematuria
- •Factitious Hematuria
- •Menstruation
- •Aetiology
- •Malignancy
- •Urinary Calculi
- •Infection and Inflammation
- •Benign Prostatic Hyperplasia
- •Trauma
- •Drugs
- •Nephrological Causes
- •Assessment
- •History
- •Examination
- •Investigations
- •Dipstick Urinalysis
- •Cytology
- •Molecular Tests
- •Blood Tests
- •Flexible Cystoscopy
- •Upper Urinary Tract Evaluation
- •Renal USS
- •KUB Abdominal X-Ray
- •Intravenous Urography (IVU)
- •Computed Tomography (CT)
- •Retrograde Urogram Studies
- •Magnetic Resonance Imaging (MRI)
- •Additional Tests and Renal Biopsy
- •Intractable Hematuria
- •Loin Pain Hematuria Syndrome
- •References
- •27: Benign Prostatic Hyperplasia (BPH)
- •Historical Background
- •Pathophysiology
- •Patient Assessment
- •Treatment of BPH
- •Watchful Waiting
- •Drug Therapy
- •Interventional Therapies
- •Conclusions
- •References
- •28: Practical Guidelines for the Treatment of Erectile Dysfunction and Peyronie´s Disease
- •Erectile Dysfunction
- •Introduction
- •Diagnosis
- •Basic Evaluation
- •Cardiovascular System and Sexual Activity
- •Optional Tests
- •Treatment
- •Medical Treatment
- •Oral Agents
- •Phosphodiesterase Type 5 (PDE 5) Inhibitors
- •Nonresponders to PDE5 Inhibitors
- •Apomorphine SL
- •Yohimbine
- •Intracavernosal and Intraurethral Therapy
- •Intracavernosal Injection (ICI) Therapy
- •Intraurethral Therapy
- •Vacuum Constriction Devices
- •Surgical Therapy
- •Conclusion
- •Peyronie´s Disease (PD)
- •Introduction
- •Oral Drug Therapy
- •Intralesional Drug Therapy
- •Iontophoresis
- •Radiation Therapy
- •Surgical Therapy
- •References
- •29: Premature Ejaculation
- •Introduction
- •Epidemiology
- •Defining Premature Ejaculation
- •Voluntary Control
- •Sexual Satisfaction
- •Distress
- •Psychosexual Counseling
- •Pharmacological Treatment
- •On-Demand Treatment with Tramadol
- •Topical Anesthetics
- •Phosphodiesterase Inhibitors
- •Surgery
- •Conclusion
- •References
- •30: The Role of Interventional Management for Urinary Tract Calculi
- •Contraindications to ESWL
- •Complications of ESWL
- •PCNL Access
- •Instrumentation for PCNL
- •Nephrostomy Drains Post PCNL
- •Contraindications to PCNL
- •Complications of PCNL
- •Semirigid Ureteroscopy
- •Flexible Ureteroscopy
- •Electrohydraulic Lithotripsy (EHL)
- •Ultrasound
- •Ballistic Lithotripsy
- •Laser Lithotripsy
- •Ureteric Stents
- •Staghorn Calculi
- •Lower Pole Stones
- •Horseshoe Kidneys and Stones
- •Calyceal Diverticula Stones
- •Stones and PUJ Obstruction
- •Treatment of Ureteric Colic
- •Medical Expulsive Therapy (MET)
- •Intervention for Ureteric Stones
- •Stones in Pregnancy
- •Morbid Obesity
- •References
- •Anatomy and Function
- •Pathophysiology
- •Management
- •Optical Urethrotomy/Dilatation
- •Urethral Stents
- •Preoperative Assessment
- •Urethroplasty
- •Anastomotic Urethroplasty
- •Substitution Urethroplasty
- •Grafts Versus Flaps
- •Oral Mucosal Grafts
- •Tissue Engineering
- •Graft Position
- •Conclusion
- •References
- •32: Urinary Incontinence
- •Epidemiology and Risk Factors
- •Pathophysiology
- •Urge Incontinence
- •Conservative Treatments
- •Pharmacotherapy
- •Invasive/ Surgical Therapies
- •Stress Urinary Incontinence
- •Male SUI Therapies
- •Female SUI Therapies
- •Mixed Urinary Incontinence
- •Conclusions
- •References
- •33: Neurogenic Bladder
- •Introduction
- •Examination and Diagnostic Tests
- •History and Physical Examination
- •Imaging
- •Urodynamics (UDS)
- •Evoked Potentials
- •Classifications
- •Somatic Pathways
- •Brain Lesions
- •Cerebrovascular Accident (CVA)
- •Parkinson’s Disease (PD)
- •Multiple Sclerosis
- •Huntington’s Disease
- •Dementias
- •Normal Pressure Hydrocephalus (NPH)
- •Tumors
- •Psychiatric Disorders
- •Spinal Lesions and Pathology
- •Intervertebral Disk Prolapse
- •Spinal Cord Injury (SCI)
- •Transverse Myelitis
- •Peripheral Neuropathies
- •Metabolic Neuropathies
- •Pelvic Surgery
- •Treatment
- •Summary
- •References
- •34: Pelvic Prolapse
- •Introduction
- •Epidemiology
- •Anatomy and Pathophysiology
- •Evaluation and Diagnosis
- •Outcome Measures
- •Imaging
- •Urodynamics
- •Indications for Management
- •Biosynthetics
- •Surgical Management
- •Anterior Compartment Repair
- •Uterine/Apical Prolapse
- •Enterocele Repair
- •Conclusion
- •References
- •35: Urinary Tract Fistula
- •Introduction
- •Urogynecologic Fistula
- •Vesicovaginal Fistula
- •Etiology and Risk Factors
- •Clinical Factors
- •Evaluation and Diagnosis
- •Pelvic Examination
- •Cystoscopy
- •Imaging
- •Treatment
- •Conservative Management
- •Surgical Management
- •Urethrovaginal Fistula
- •Etiology and Presentation
- •Diagnosis and Management
- •Ureterovaginal Fistula
- •Etiology and Presentation
- •Diagnosis and Management
- •Vesicouterine Fistula
- •Etiology and Presentation
- •Diagnosis and Management
- •Uro-Enteric Fistula
- •Vesicoenteric Fistula
- •Pyeloenteric Fistula
- •Urethrorectal Fistula
- •References
- •36: Urologic Trauma
- •Introduction
- •Kidney
- •Expectant Management
- •Endovascular Therapy
- •Operative Intervention
- •Operative Management: Follow-up
- •Reno-Vascular Injuries
- •Pediatric Renal Injuries
- •Adrenal
- •Ureter
- •Diagnosis
- •Treatment
- •Delayed Diagnosis
- •Bladder and Posterior Urethra
- •Bladder Injuries: Initial Management
- •Bladder Injuries: Formal Repair
- •Anterior Urethral Trauma
- •Fractured Penis
- •Penile Amputation
- •Scrotal and Testicular Trauma
- •Imaging
- •CT-IVP (CT with Delayed Images)
- •Technique
- •Cystogram
- •Technique
- •Retrograde Urethrogram (RUG)
- •Technique
- •Retrograde Pyelogram (RPG)
- •Technique
- •One-Shot IVP
- •Technique
- •References
- •37: Bladder Cancer
- •Who Should Be Investigated?
- •Epidemiology
- •Risk Factors
- •Role of Screening
- •Signs and Symptoms
- •Imaging
- •Cystoscopy
- •Urine Tests
- •PDD-Assisted TUR
- •Pathology
- •NMIBC and Risk Groups
- •Intravesical Chemotherapy
- •Intravesical Immunotherapy
- •Immediate Cystectomy and CIS
- •Radical Cystectomy with Pelvic Lymph Node Dissection
- •sexual function-preserving techniques
- •Bladder-Preservation Treatments
- •Neoadjuvant Chemotherapy
- •Adjuvant Chemotherapy
- •Preoperative Radiotherapy
- •Follow-up After TUR in NMIBC
- •References
- •38: Prostate Cancer
- •Introduction
- •Epidemiology
- •Race
- •Geographic Variation
- •Risk Factors and Prevention
- •Family History
- •Diet and Lifestyle
- •Prevention
- •Screening and Diagnosis
- •Current Screening Recommendations
- •Biopsy
- •Pathology
- •Prognosis
- •Treatment of Prostate Cancer
- •Treatment for Localized Prostate Cancer (T1, T2)
- •Radical Prostatectomy
- •EBRT
- •IMRT
- •Brachytherapy
- •Treatment for Locally Advanced Prostate Cancer (T3, T4)
- •EBRT with ADT
- •Radical Prostatectomy
- •Androgen-Deprivation Therapy
- •Summary
- •References
- •39: The Management of Testis Cancer
- •Presentation and Diagnosis
- •Serum Tumor Markers
- •Primary Surgery
- •Testis Preserving Surgery
- •Risk Stratification
- •Surveillance Versus Primary RPLND
- •Primary RPLND
- •Adjuvant Treatment for High Risk
- •Clinical Stage 1 Seminoma
- •Risk-Stratified Adjuvant Treatment
- •Adjuvant Radiotherapy
- •Adjuvant Low Dose Chemotherapy
- •Primary Combination Chemotherapy
- •Late Toxicity
- •Salvage Strategies
- •Conclusion
- •References
- •Index
15
Pathophysiology of Renal Obstruction
Glenn M. Cannon and Richard S. Lee
Causes of Renal Obstruction
Renal obstruction can be caused by intrinsic or extrinsic factors that affect the ureters, bladder, or urethra. Most of the literature concerning the pathophysiology of renal obstruction has focu sed on unilateral ureteral obstruction (UUO) or bilateral ureteral obstruction (BUO). Table 15.1 lists possible causes of renal obstruction.
Effects on Prenatal Development
Prenatal Hydronephrosis
Ultrasound has remained the main diagnostic tool in evaluation of prenatal hydronephrosis since its introduction in 1980.1 Historically, the degree of anteroposterior renal pelvic diameter has been used as an indicator to predict need for surgery.A renal pelvic diameter of <12 mm with out caliectasis poses a minimal risk of eventually requiring surgery, while severe dilatation of >50 mm may inevitably require surgery.1 Diuretic renal scanning aids the evaluation of infants between these two extremes and has been dem onstrated to be reliable over the age of 6 weeks to 2 months.2 Serial ultrasound examination is fre quently utilized and a trend of progressive hydro nephrosis on two consecutive examinations serves as an early diagnostic sign of obstruc tion.3 Society of Fetal Urology (SFU) Grade of 3–4 of postnatal hydronephrosis and a relative
renal function of <40% are both independent risk factors for the eventual need for surgery.
Lee et al. performed a metaanalysis includ ing 1,308 patients with prenatal hydronephrosis and postnatal followup that concluded that children with any degree of prenatal hydroneph rosis are at greater risk of postnatal pathology compared with the normal population.4 They found that children with moderate hydroneph rosis (defined as AP diameter 7–10 mm for sec ond trimester, 9–15 mm for third trimester) and severe hydronephrosis (AP diameter > 1m for second trimester, >15 mm for third trimester) were at significant risk for postnatal pathology, and postnatal diagnostic studies should be con sidered. The authors also concluded that even children with mild prenatal hydronephrosis may carry a greater risk as compared to the normal population for postnatal pathology. The optimal postnatal management of patients with mild prenatal hydronephrosis is controversial and further prospective studies are needed.
Spectrum of Renal Abnormalities
Congenital ureteropelvic junction obstruction (UPJO) can cause a spectrum of renal abnor malities.5,6 In its mildest form, UPJO represents the radiological demonstration of reversible hydronephrosis without permanent renal dam age. Its most severe form represents a hypertro phic and fibrotic UPJ with renal parenchymal changes such as glomerulosclerosis, chronic tubulointerstitial injury, and dysplasia that may
C.R. Chapple and W.D. Steers (eds.), Practical Urology: Essential Principles and Practice, |
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DOI: 10.1007/978-1-84882-034-0_15, © Springer-Verlag London Limited 2011 |
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Table 15.1. Possible causes of renal obstruction |
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Urethral stricture |
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Ureter |
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Urethral carcinoma |
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Intrinsic |
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Urethral atresia |
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Ureteropelvic junction obstruction |
Extrinsic |
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Ureterovesical junction obstruction |
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Prostate carcinoma |
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Ureteral valve |
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Penile carcinoma |
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Ureteritis cystica |
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tuberculosis |
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schistosomiasis |
necessitate nephrectomy.7 Renal biopsies per |
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Ureteral carcinoma |
formed in patients after pyeloplasty demon |
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strate relatively wellmaintained parenchyma in |
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Papillary necrosis |
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which the only overt changes are mainly |
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calculus |
glomerular.7 |
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Endometriosis |
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Blood clot |
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Fungal bezoar |
Signaling Pathways and Tissue |
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Extrinsic |
Interactions |
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crossing lower pole vessel at ureteropelvic junction |
Recent finding from gene expression studies |
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retroperitoneal fibrosis |
and embryological mutants have resulted in a |
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better understanding of ureteral development |
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retroperitoneal tumor |
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and its effect on the developing renal paren |
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abdominal aortic aneurysm |
chyma. Glialderived neurotropic factor (Gdnf) |
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is released from the metanephric blastema and |
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cervical cancer |
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induces ureteral bud growth from the Wolffian |
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Prostate cancer |
duct.8 Airik et al. have demonstrated that the |
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retrocaval ureter |
transcription |
factor gene |
Tbx18 is |
initially |
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expressed between the Wolffian duct and meta |
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tubo-ovarian abscess |
nephric mesenchyme in mouse embryos and is |
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diverticulitis |
later |
found exclusively at |
the distal |
ureteric |
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stalk.9 This implies that the ureteric mesen |
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gravid uterus |
chyme is differentiated shortly after ureteral |
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Bladder |
budding, which occurs before the differentia |
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tion of ureteric epithelium. Several investiga |
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Intrinsic |
tors have identified that the signaling molecule |
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Bladder carcinoma |
Bmp4 also plays a key role in the specification |
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and differentiation of the ureteric bud.1012 |
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calculi |
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Both urothelial and smooth muscle develop |
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neurogenic bladder |
ment are significantly impaired after inactiva |
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tion of the Bmp4 gene. Deletion of the signaling |
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Extrinsic |
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molecule Bmp4 or the angiotensin type II |
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Pelvic lipomatosis |
receptor can result in ectopic Gdnf signaling |
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Urethra |
that |
results |
in multiple |
ureteric |
buds.1315 |
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Multiple other genes have been identified as |
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Intrinsic |
playing a role in ureteral development and |
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Posterior urethral valve |
mutations in any of them may result in urinary |
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tract obstruction.8 |
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