Obstructive Uropathy
Definition Aetiology (Causes)
Obstruction of Urinary Tract
Lead to Renal Impairment
Classification
Causes Congenital, Acquired
Duration Acute, Chronic
Degree Partial, Complete
Level Upper Urinary Tract, Lower Urinary Tract
Anatomy
Congenital Acquired
Congenital Narrowing Urethral stricture (Infection, Injury)
Meatal stenosis
Distal urethral stenosis
Benign Prostatic Hyperplasia (BPH)
Prostate Cancer
Posterior urethral valve (PUV)
Ectopic ureters
Bladder Tumour
(Bladder neck, Ureteral orifices)
Ureterocoeles
Ureterovesical (VUJ)
Ureteropelvic Junctions (PUJ) Stenosis
CaP, Cervical cancer (CaCx)
(extension into base of bladder
occluding ureters)
S2-S4 Sacral Root Damage
Spina Bifida
Compression o f Ureters at Pelvic Brim
by metastatic nodes from CaP, CaCx
Myelomeningocoele Ureteral Stones
Vesicoureteric Reflux (VUR) Retroperitoneal Fibrosis
Malignant Tumour
Pregnancy
Neurogenic Bladder
Pelvi-Ureteric Junction (PUJ) Obstr.
Stones
VUR
Staghorn Calculi
Bilateral VUR due to PUV
Bladder Outlet Obstruction (BOO)
Bilateral VUR 2° to
Prune Belly Syndrome
Tumours
Stricture
Pathophysiol ogy Upper Tract Changes
Obstruction, Neuropathic Bladder Dysfunction
have same effects on GUT
Lower Tract
Upper Tract
(Ureter, Kidney)
Distal to Bladder Neck
Severe external urinary
meatal stricture
BPH
Bladder
BPH
Hydroureter (HU)
Hydronephrosis (HN)
Ureter
Early Stages
Intravesical Pressure is Normal when
Bladder fills
Pressure . onlyin Voiding
Pressure is not Transmitted to
Ureters, Renal Pelves because
competence of VUJ valves
Late Stages
Decompensation + Residual Urine
.
Added Stretch Effec t
.
Incompetence of VUJ valves
.
VUR
Lower Tract Changes (Bladder)
Obstruction
.
. Hydrostatic Pressure
.
Dilation of Urethra
. . .
Diverticulum Prostatic Duct Dilation Infected Urine
.
Extravasation
.
Periurethral Abscess
Trigonal Hypertrophy
.
Further Hyd roureteronephrosis
.
. Resistance Urine Flow
.
Progressive Back Pressure on
Ureter, Kidney
.
Hydroureter, Hydronephrosis
Kidney
Normal Kidney Pressure 0
When Pressure . -Pelvis, Calyces Dilate
2° to Back Pressure
(due to reflux, obstruction)
.
Ureteral Musculature Thickens
(push urine downward by peristaltic
activity Compensation Stage)
.
Elongation, Tortousity of Ureter
Fibrous tissueband formation
.
Further Angulate Ureter
(during contraction)
.
2° Ureteral Obstruction
Atthisstage,removal of obstructionbelow
may not prevent Kidney from undergoing
progressive obstruction
Ureteral Wall Attenuated
(due to . Pressure)
.
Contractile Power is Lost
(Decompensation stage)
.
Severe Ureteral Dilatation
(like Bowel Loops)
2 Stages
(depend on duration, degree, site)(the higher, the greater effect on Kidney)
Compensation Decompensation
Bladder musculature Hypertrophy Decompensation of
(to balance . urethral resistance) Detrusor Muscle results in
presence of Resid ual Urine (RU)
after voiding
Trabeculation of Bladder Wall
Cellules
Diverticula
Mucosal changes
If Intrarenal Pelvis -Parenchyma affected (compared to extrarenal)
Early Stage Later Stage
Pelvic musculature Hypertrophy Muscle become Stretched
(to force urine past obstruction) . Atonic (Decompe nsated)
Progression of Hydronephrotic Atrophy
Trabeculation of Bladder Wall
Normal Mucosa Smooth
Hypertrophy
.
Individual muscles bundle become taut
.
Coarse interwoven appearance
Earliest change Calyceal Hydronephrosis
With . Pressure, Normal Concave Calyx
become Flattened then become Convex (clubbed)
Renal Parenchymal changes due to
Compression atrophy (from . Intrapelvis Pressure)
Ischaemic Atrophy (from Haemodynamic changes)
(manifested in Arcuate vessels that run at base of Pyramids) . Spotty Atrophy
Tubules become Dilated
Cells Atrophy from Ischaemia
Hydronephrosis (unusual type of Pathologic change)
Trigonal muscle, Interureteric ridge Hypertrophy
.
.Resistanceurineflowin Intravesical ureteral segments
.
Functional obstruction of VUJ
.
Back Pressure on Kidney
.
Hydroureter, Hydronephrosis
Obstruction . in the presence of Significant Residual Urine
Cellules
Mucosa between Superficial Muscle Bundles is Pushed
.
Formation of Small Pockets (Cellules)
Diverticula
Cellules force through entirely the musculature of Bladder Wall
.
Saccules
.
Diverticula
May be embedded in Perivesical Fat or covered byPeritoneum
(depending on location)
Only in Unilateral Hydronephrosis
Advanced stages of Hydronephrotic Atrophy is seen
Eventually, Kidney become
Completely Destroy ed
Appears as Thin-Walled Sac filled with Clear Fluid, Pus
. Intrarenal Pressure
Cause Suppression of Renal Function
The Closer Intrapelvic Pressure approaches Glomerular Filtration Pressure
The . Urine can be secreted
GFR, RBF .
Concentrating Power is Gradually Lost
Urea/Crea tinine Ratio . (compared to Normal Kidney)
Completely Obstructed Kidney
Continue to secrete Urine (which is reabsorbed via Tubules, Lymphatics)
(Normally other secreting organs cease sec reting when completely obstructed)
Intrapelvic Pressure . Rapidly
.
Extravasa tion of Urine from Renal Pelvis into Parenchymal Interstitium
(reabsorbed by lymphatics)
.
. Intrapelvic Pressure
(Allow Further Filtration)
Unable to expel content efficiently into Bladder after 1° obstruction has been rem
oved
Compensation
(No Muscle Wall)
Markedly Hydronephrotic Kidney continue to Function
Does not contain true urine (only H2O, Salts)
As Unilateral Hydronephrosis Progress
Normal Kidney undergo compensatory hypertrophy (Maintain Total Renal Function)
Successful Anatomical Repair of Obstruction of Kidney
Fail to Improve Powers ofElimination
If Both Kidney Equally Hydronephrosis
Strong Stimulus Continually Exerted on Both to Maintain Maximum Function
Clinical Features Recovery of Function
Loin Pain (due to Capsule Stretch, Presence of Calculu s, Infection )
Ureteric, Renal Colic
Complete Anuria
Complete Bilateral Obstruction
Complete Obstruction of Single Functioning Kidney
Polyuria
Partially Obstruction impairment of Renal Tubular Concentrating Ability
Hematuria (Microscopic/ Occult)
Urinary Stones
Malignancy
Infection
Uraemia
Bilateral Obstruction, Obstruction of a solitary Kidney
Results in
Weakness
Pallor
Weight Loss
Peripheral Edema
Mental status change
Depend on
Degree of Obstruction
Duration of Obstruction
Prevent Renal Impairment
Relief of Complete Urinary Obstruction should be achieved expediently
Decompress Urinary System Temporarily
Temporary Drainage device
Until Management can be executed
Obstruction & Infection
Urological emergency
Require
Immediate relief
(Foley Catheter, Ureteral Stent, Percutaenous Nephrostomy Tube)
Broad spectrum Antibiotics (prevent Life-threatening Urosepsis)
Relieve Obstruction (Decompress Upper Tract Obstruction)
Investigations
KUB X-Ray
Renal Function Test (RFT)
Urine
Full Microscopic Examination (FEME)
Culture, Sensitivity (C&S)
Ultrasound
KUB
Urinary Tract
Intravenous Urography (IVU)
CT Urography/ CT Renal Protocol
Retrograde Pyelography (RPG)
Antegrade Pyelography (APG)
DTPA
DMSA
Ureteral Stent Percutaenous Nephrostomy
Small tube
Renal Pelvis . Bladder
(placed endos copically, with
Fluoroscopic guidance )
Small Tube
Placed through Flank
Directly into Renal Pelvis
(percutaneously by Urologist,
Interventional Radiologist) Performed in Operating Room (OR)
Under Local Anaesthesia (LA)
Adequate Sedation
Require only Local Anaesthesia (LA)
Complications
Treatment
Pyelonephritis, Pyonephrosis
Aims
Relieve Obstruction
Treat Underlying Cause
Prevent, Treat Infection
Relief Symptoms
Preserve Renal Function
Depend on
Degree of Obstruction
Renal Impairment
Infection
Site of Obstruction
Expeditious Intervention, Hos pitalization
Complete Obstruction
Obstruction of a Solitary Kidney
Infection (Fever, Leukocytosis, Bacteriuria)
Azotemia
Uncontrolled Colic Pain
Nausea, Vomiting, Dehydration
(eg. gross pus within obstructed renal pelvis of a funtionless kidney)
Abscess formation
Urosepsis
Urinary Extravasation with Urinoma Formation
Urinary Fistula Formation
Renal Parenchymal Loss
(long term obstruction leading to renal insufficiency, failure)
Pyonephrosis
Prognosis
Depend on
Cause
Medical Treatment
Analgesics Antibiotics
Voltaren Bactrim
Pethidine Trimethoprim
Zinnat
Ciprobay
Site
Degree (partial, complete)
Duration of Obstructive process
Presence of Concomitant Infection
Favourable Prognosis Expected if
Renal Function Good
Obstruction Corrected
Infection Eradicated
