Urinary Tract Obstruction14032007

Urinary Tract Obstruction

Zheng Xuepei

MD

Section I Introduction Urinary tract:  Renal tubules  Calyx  Pelvis  Ureter  Bladder  Urethra

Common Causes of Obstruction

Etiological Types

Causes  Urolithiasis (stone)  Congenital anomaly  Tumor  Tuberculosis  Trauma  Infection

Age and sex  Children: congenital anomalies  Young and middle aged people: Urolithiasis Stricture from trauma  Aged people: benign prostatic hypertrophy Tumors  Women: pelvic tumor

Common Location and Causes  Upper urinary tract: Location: Ureter Cause: stone Results: unilateral hydronephrosis  Lower urinary tract: Location: urethra Cause: stricture Results: bilateral hydronephrosis

Common Causes of Obstruction

Pathophysiology  Basic pathology: Dilation of urinary tract above obstruction  Processes: Early stage: obstruction➔wall of urinary tract thickened ➔contractility reinforced. Late stage: wall of urinary tract thinned, smooth muscle atrophied ➔ contractility decreased ➔distention of urinary tract above the obstruction. Hydronephrosis .

Reflux of Urine After Obstruction Four passages  Pelvis-- lymphatic bypass  Pelvis--veins bypass  Pelvis--renal sinus bypass  Pelvis--renal tubules bypass

Reflux of Urine

Progress of hydronephrosis

Results  Infection:  Urolithiasis  Insufficient renal function ➔uremia.

Section II

Hydronephrosis

Concept: More extensive dilitation of the pelvis and calices with resulting thinning of renal parenchyma after obstruction of urinary tract.

Etiology  Anomalies: 1. Stricture at the ureteropelvic junction; 2. Extrinsic compression : aberrant vessels, fibrous bands and adhesions  Stone; Tumor; Infection; Tuberculosis  Surgical ligation

Physiological Phenomenon  hydronephrosis in pregnant women: 1. Progesterone ➔tensions of pelvic and ureter smooth muscles decreased and relaxed. 2. Ureter is oppressed by enlarged uterus.

Progress of hydronephrosis (1) These depend on the speed, degree and duration of obstruction 1. Acute, total obstruction of ureter: Unilateral: Renal parenchyma atrophies rapidly, and size of kidney dose not enlarge distinctly ➔ Renal function declines rapidly. Bilateral: anuria, an emergency condition, postrenal failure may occur. So does the solitary kidney.

Progress of hydronephrosis(2) 2. Chronic, partial obstruction of urinary tract: kidneys of hydronephrosis enlarge distinctly; renal function declines gradually. The higher the position of obstruction, the more severe of hydronephrosis, and the sooner renal function declines.

Gigantic hydronephrosis The quantity of urine in the pevis due to hydronephrosis is over 1000ml in adults, or over 24 hours’ urine volume in children.

( Normal pelvis capacity is 10ml.)

Symptoms  No symptoms;  Discomfort and mass in upper abdomen;  Symptoms of primary diseases: Infection: chill, fever, pain, pyuria; Stone: renal colic Tumor: hematuria, Renal dysfunction: nausea, vomiting BPH and urethral stricture: difficult urination

Diagnosis (1)  History, symptoms.  X-ray examination: Plain film: stone shadow, enlarged kidney IVP: intravenous pyelography inject contrast medium (Urografin) through veins

Estimate the degree of hydrops State of renal function Position of obstruction

Diagnosis (2) 

RP: ( Retrograde pyelography ) If IVP does not success, RP is used.

Diagnosis (3)  B ultrasound examination:  Renogram determination: Method: isotope 99mdtpa is intravenously injected

Can show if obstruction is present

Treatment (1) Principles of treatment: Relieve obstruction, protect renal function.

 Causal treatment: remove causes Stricture of ureteropelvic junction: pyeloplasty, Nephrolithiasis: pyelolithotomy, or lithotripsy Calculus of ureter: ureterolithotomy

pyeloplasty

Treatment (2)  nephropyelostomy: The causes can not removed for emergency conditions such as severe infection, insufficient renal function or anuria, urine should drained temporarily with this operation.

 nephrectomy: Indications: Severe hydronephrosis, much less of residual renal tissue or severe infection. Prerequisite: The opposite kidney is good.

Nephropyelostomy

Section 3 Benign prostatic hyperplasia  BPH

Introduction 

BPH is a common disease in older males, incidence trend to increase along with the higher average life-span.

 BPH occurs from 35 years of age, but have clinical symptoms until over 50.

Etiology (1) 1. Normal growth and development of prostate depend on male hormones. 2. There is no BPH in aged male who had been orchiectomy in his teen-age. 3. Basic conditions: aged and intact testis.

Etiology (2) Etiology is not definitely known theories 1. Endocrine origin -- a disturbance of balance between the production of male and female hormones. ( Testosterone, Dihydrotestosterone, Estradiol ) 2. Stromal-epithelial interactions. 3. Effects of various growth factors.

Pathology  Prostate: composed of glandular tissue and smooth muscle  Prostate: periurethral region and peripheral region  Prostatic hyperplasia occur at periurethral region, and peripheral region be compressed into surgical capsule.

Normal Prostate

Benign prostatic hyperplasia

Benign prostatic hyperplasia

Hyperplasia tissue: Fibrous tissue --- harder Glandular tissue --- softer  Enlarged prostate compress the urethra, and urethra becomes longer, and curved.

Prostate Normal:

BPH:

weight 20g, Size 2× 3 × 4cm Shape like a chestnut weight 30~80g, or over 100g

pathophysiology 1. Difficult urination, residual urine. 2. detrusor and Bladder wall thickened. 3. Trabeculation and false diverticulum. 4. Dilated bladder and ureter. 5. Reflux -- Hydroureter and hydronephrosis. 6. Renal function decline, at last uremia occurs. 7. Infection , stone.

Trabeculation, False diverticulum

Symptoms

1. Frequency: The earliest symptom of BPH. Normal: 4~6/0~1 times at day/night time. Early stage: nocturnal frequency, caused by congestion of the prostate. Late stage: frequency worsen, related to residual urine and decline of useable capacity of the bladder, and / or complicated with urinary infection.

2. Difficult urination: Progressively difficult urination is the main symptom of BPH, including hesitancy, difficult starting, weak stream, abdominal straining, prolonged urination time, slowness of the urine stream, shortness of urine range, small urine line, terminal dribbling. Stuttering urination. Leakage.

3. Retention and incontinence of urine: As the worsen of obstruction, partial retention occurs, inability to empty the bladder completely; residual urine is present in these cases.

Overflowing incontinence occurs when residual urine is large enough, especially during sleepping (enuresis). Acute retention may occur when prostate and mucosa of bladder neck get congestion suddenly after drinking wine, getting cold or constipation.

4. Other symptoms: Irritating symptoms: urgency and pain. Complicating with urinary infection. Hematuria: congestion, rupture of dilated vessels; bladder stone. .

Hydronephrosis: Insufficiency of renal function: Hernia, hemorrhoid, prolapse of anus: High pressure of abdominal cavity

Diagnosis

History 1. Males over 50 years of age who have symptoms of urgency and difficult urination. 2. Cystitis, bladder stone or insufficient of renal function occur in aged patients. BPH should be considered in these cases.

Clinical Examination 1. Digital examination of prostate through the anterior rectal wall: The hypertrophied prostate by rectal palpation is larger than normal, is smooth in contour and elastic in consistency, has welldefined edges, is not firmly fixed, and the median groove is obliterated.

Degree of Hypertrophied Prostate Degree I : as large as a chicken- egg; 20~50g Degree II: as large as a duck- egg; 50~70g Degree III: as large as a goose-egg; over 70g

2. Estimation of residual urine: the patient voids all he can, then a small catheter is gently passed and the urine found to have been retained in the bladder is measured. This is benefit to estimate the degree of obstruction and difficult urination, and is helpful to the choice of treatment.

3. B ultrasound examination: Exact diameters of prostate The weight of the gland can be estimated Residual urine, Bladder stone, Distinguish from prostate cancer.

4. Cystoscopy: Enlarged prostate The trabeculation false diverticulum of bladder stone

Trabeculation, False diverticulum

Differential Diagnosis 1. Contracture of bladder neck: Caused by chronic inflammation of bladder neck Symptoms similar to BPH Normal size of prostate

2. Prostate cancer: The prostate is stony hard, fixed and frequently irregular Serum PSA elevated. Biopsy study

3. Neurogenic bladder: It has a evident history and signs of nervous lesion, and sensory and motor nerve dysfunction. Relaxed anal sphincter.urodynamic study and cystography are helpful to diagnosis.

Treatment 1. Medical therapy: α 1 -adrenoceptor antagonists: reduce the tension of urethral smooth muscle and obstruction of urethra, and relieve of urination symptoms. Harnel 1mg, QN, PO;

5α -reductase inhibitors: They can reduce the content of dihydrotestosterone in the prostate. Pless ( Finasteride ) 1 tab. QD, PO. 3 months later, the volume of the gland become less.

2. Surgical therapy: Indications: A. Residual urine over 50ml. B. A history of acute retention of urine. C. Evident difficult of urination, frequent nocturia D. Complicated with bladder stone, diverticulum and hydronephrosis.

Operation methods: A. Transurethral resection of prostate. B. Transperineal prostatectomy C. suprapubic prostatectomy D. retropubic prostatectomy

Prostatectomy

Pre- and Post-operation

Suprapubic cystostomy