Urolithiasis 7

Urolithiasis Zheng Xuepei

MD

Introduction Urinary calculi, urinary stones A common disease of urinary system Described in old medical book named “Huang-Di-Nei-Jing” in ancient china. Found in bodies of mummies 3000 years ago in Egypt .

Incidence 1. 20~50 years of age, most in 30~40. 2. Males more than females ( 4 : 1 ). 3. Southern areas more than Northern areas.

4. Upper urinary tract stones six times more than lower urinary tract stones. 5. Primary stones four times more than secondary stones.

Etiology 1. Pathogenesis:

Not completely clear. Urolithiasis is a disease of pathological mineralization..

2. Components of stones Crystal components: 98% Calcium oxalate;

urate;

Uric acid and

Others

Matrix: 2% Protein ( 65% ); Carbohydrate ( 15% ); Inorganic mineral (10%); Water (10%)

3. Theories 1. super-saturation-crystallization. Normal urine is often in the state of oversaturation, if the crystal components is supersatuated, crystalization may occur.

Saturation→supersaturation →nucleation →crystal growth or aggregation → crystal retention →stone formation.

2. Theory of inhibitors: Decrease of inhibitors. Inhibitors can inhibit the process of stone formation. magnesium, citrate, pyrophosphate, et al

3. Theory of matrix: Matrix is the component of stone, it may accelerate the formation of stone.

4. Theory of comprehensive factors. All above.

4. Etiological factors 1. Factors of urinary tract: Infection: necrotic tissue, mass of bacteria and mucus may form a nucleus. Obstruction : crystals are retained. Foreign bodies: thread, catheter, calcareous material is deposited on them.

2. Factors of urine: super-saturation of stone-forming components: Calcium: Hyperparathyroidism, Idiopathic hypercalciuria Bone fracture Oxalate: Hyperoxalaluria Uric acid: Gout

Changes of urine ph value: Aciduria: uric acid and cystine stones. Alkalinuria: phosphate stone

Decrease of urinary output: Insufficient ingestion of fluids, Perspiration, urine is concentrated.

Decrease of urinary inhibitors: Citrate, magnesium, citrate, Pyrophosphate, etc.

3. Other factors: Climate Geographic factors Water Metabolic factors Genetic factors

5. Classification Primary stone ( metabolic stone ): Calcium oxalate, Cystine, Uric acid and urate Secondary stone ( infectious stone ): Calcium phosphate Ammoniomagnesium phosphate

Calcium oxalate: Brown color, very hard, granular surface like a mulberry seed, radiopaque.

Ammoniomagnesium phosphate and calcium phosphate: Dirty white, hard, friable, coarse on surface, staghorn shape, radiopaque and laminated in plain film.

Urate and uric acid stone: Yellowish-red, smooth, hard, oval, radiolucent.

Radiolucent stone is also called as negative stone.

6. Pathology 1. Direct injury: congestion, edema, rupture and bleeding of mucosa. 2. Obstruction: Dilation and hydrops above the obstruction. Renal parenchyma atrophied in severe case. Difficult urination and retention of urine.

3. Infection: Obstruction→infection →pyonephrosis →severe injury of renal function. Stone , obstruction and infection are cause and effective relationship among them. 4. Canceration: Long-term irritation on mucosa,

Treatment 1. Adequate fluid intake Sufficient fluid intake, by minimizing urine concentration, aids in prevention of stone formation. 3000ml of water should consumed in 24 hours by stone formers . Evidence does not support the belief that distilled water helps to prevent urinary calculi, nor the hard water is a risk factor.

2. Get rid of risk factors: Relieve urinary tract obstruction: BPH, urethral and ureteral stricture.

Control urinary tract infection: Maintenance of free urine drainage: patients such as fracture and poliomyelitis who require bed rest,, need exercise and change position several times daily.

3. Diet: According to the components of stone, measurements are adopted. Foods in high oxalates: Spinach, tea, potato, etc. Foods rich in calcium: Dairy products, bean curd.

4. Medication: oxalate stone: Vitamin B6 Magnesium oxide.

Phosphate stones: Infection should be controlled. Low phosphorous and low calcium diet. Ammonia chloride 3g daily, Acidifying the urine ; Increase the solubility of phosphate.

uric acid stones: foods Rich in purines should be limited. lean meats, animal liver, braines, kidneys, beef, beans, coffee, tea, etc.

Sodium bicarbonate 4g daily, Alkalinizing the urine; Increase the solubility of uric acid.

Section Two Calculus of kidneys and ureters Calculus in the pelvis or a calix, high incidence in young and middle aged males, mostly unilateral. Most Ureterolith come from kidney, stay at middle and lower segments because of gradually thinner of the ureter.

There are three physiological strictures along the ureter, they locate at pelvic-ureter juncture, cross-over iliac vessel and intravesical ureter respectively. Lower one third segment is the most common location of ureter stone.

There is irritation of the pelvic mucosa, causing infection which soon involves the parenchyma; The stone may cause obstruction to urinary flow from the pelvis or from a calix with resulting dilitation and increased infection, Kidney become entirely destroyed.

Clinical Manifestations Symptoms of kidney calculi are similar to that of ureter stones. There may be none; These are the silent stone which are fixed solidly in a calix or in the pelvis and several calices (staghorn calculus) and do not obstruct urinary outflow. Stone may be found occasionally through health examination or x-ray films.

1. Pain pain is the most common symptom of renal calculi. dull ache in the lumbar region to sharp, severe colic which occurs when the stone obstructs the outflow of urine from the kidney. Pain is usually intermittent, its severity being in direct proportion to the degree of obstruction; frequently a dull aching pain occurs between colicky attacks. Typical renal pain is referred to the lower abdomen and groin, and sometimes to the testis or labia on the involved side.

2. Hematuria: blood may appear in the urine. It is the results of injury of stones on mucosa; most are microscopic, only a few are macroscopic hematuria..

3. Other symptoms: Infection symptoms: pyuria, fever, chill, knock pain at renal region. Terminal stone of ureter: Frequency, urgency, terminal pain of urination, hydronephrosis: enlarged kidney can be palpated.

Obstruction of bilateral ureters by stones: insufficient of renal function, tired, nausea, anemia, less urine or anuria. Sometimes symptoms of infection may be the only manifestation of urinary stone.

Diagnosis 1. Diagnosis of most patients with urolithiasis can be confirmed through history, physical examination , x-ray films and laboratory procedures. 2. Renal function should be evaluated, if the obstruction and infection are present, the causes and components of stone , so as to draw up a suitable medical regimen.

3. Laboratory procedures: Values of phosphorous, calcium and uric acid in serum and urine should be assayed, so as to screen primarily hyperparathyroidism, idiopathic hypercalciuria and hyperuricosuria.

4. Urological x-rays: 95% of urolithiasis can be showed distinctly on plain films. Negative stone: do not show on plain films. But have a defect within the shadow of contrast medium.

5. B-ultrasound examination: 6. CT examination: This can find stones not dense enough to cast a shadow in x-ray films.

Differential Diagnosis 1. Stones of gallbladder and calcified mesenteric lymph nodes: Stone of right kidney is located at the back of front edge of vertibra body . 2. Phleboliths and bone island: Urogram of urinary tract.

Treatment

Medical treatment Indications: the stone is less than 0.6 cm in diameter, smooth, and there is no obstruction or infection. 1. Adequate fluid intake: Keep the daily urine more than 2000ml, so as to reduce the deposition of crystals, and be helpful to discharge the stones.

2. Discharge stones with modern and Traditional Chinese Medicine. Antispastic Diuretic drugs Acupuncture.

3. Treatment of renal colic: Renal colic is an emergency condition, and need treatment immediately. Atropine, Dolantin, Antacin, Progesterone,

ESWL Extracorporeal shock wave lithotripsy Stones localized by x-ray or supersound detection, lithotripsied by focused high energy shock wave frome lithotripter on the stone.

Indication: renal stone less than 3cm, ureteral stones. Contraindications: Urinary tract obstruction below the stone; Pregnant women; Obesity Insufficiency of blood coagulation function.

Surgical Treatment Indications: 1. Stones larger than 1cm in diameter, there is less chance to discharge naturally. 2. Stones complicated with obstruction or infection. If renal function is affected, and no effect after common treatment. 3. Obstructive factors in the urinary tract below the stones should be removed

Using a ureteral calculus dislodger Transurethral ureteropyeloscope.

Ureterolithotomy: Indications: Stone 1cm in diameter, no effects after non surgical treatment, or complicated with obstruction or infection. Pyelolithotomy: Indications: Stones larger than 1 cm in diameter, or complicated with obstruction or infection.

Nephrolithotomy: Indications: stone of calyx not removed through pelvis, or stones of multiple calyces. Anatrophic nephrolithotomy: Indications: complex staghorn renal stone,.

Nephrectomy: Indications: renal function has been destroyed by stone, or pyonephrosis. Contralateral kidney is good.

Percutaneous nephrolithotomy

Treatment Principles for Bilateral Urinary Tract Stones 1. Bilateral ureteral calculus: Ureteral stones with severe obstruction should be treated firstly. Contralateral ureter Stones can also be taken out at the same time if possible.

2. Ureteral stone complicated with contralateral renal stone: Ureteral stone should be taken out firstly.

3. Bilateral renal stones: Stones that can be taken out Easily and safely should be firstly considered. If there are severe obstruction , insufficient renal function, or general condition is poor, nephropyelostomy is necessary. Stones can be removed afterwards.

4. Anuria caused by acute complete obstruction in patients with bilateral upper tract stones or stones of solitary kidney. Perform operation immediately . Catheterization through ureter or percutaneous nephrostomy is available if general condition is poor.

Section Three Bladder Stones Primary bladder stones: Incidence: a common disease 50 years ago, now rarely happened. Boys Causes: malnutrition, lowprotein diet.

Secondary bladder stones: Incidence: much more common in males than females, ratio 20/1, Age group: older males

Causes: 1. Retention of urine: 2. Foreign bodies: grass, thread, catheters. 3. Immobilization: paraplegia; poliomyolitis. 4. Renal stone trapped in the bladder.

Symptoms 1. Urinary stream stops and

difficult urination: 2. Irritation symptoms : frequency, urgency and terminal pain during urination.

3.Hematuria: mucosa injury by stone,

Diagnosis 1. Typical history and symptoms: 2. X-ray examinations: Plain film at bladder region: size, shape, number of stones. KUB film: upper urinary tract stone ? Urogram: stones in ureter or diverticulum ?

3. B ultrasound and cystoscopy. 4. Diagnosis of causes.

Treatment Most stones are cured through cystoscope, while open operation is rarely used.

1. Lithotriptoscopy: Electrohydraulic lithotripsy. Mechanical lithotripsy. Ultrosound lithotripsy. Laser lithotripsy. Pneumatic ballistic lithotripsy.

2. Suprapubic cystolithotomy: Indication: larger stone; Bladder stone of children; Calculus in diverticulum of bladder. 3. Suprapubic cystostomy is used in bladder stones with severe infection or of children.

Section 4 Stones in Urethra Most stones in urethra are come from kidney or bladder; Much a few are formed primarily in diverticulum of urethra, or caused by urethral stricture or foreign bodies. Over 50% of the stone in the anterior urethra.

Clinical Manifestation 1. Difficult urination, pain during urination, thinned urinary stream or dribbling. 2. Pain in perineum region. 3. Acute retention of urine.

Diagnosis 1. Palpation of urethra: Stones in anterior urethra: Stones in posterior urethra: digital palpation through rectum. Urethral sound 2. B ultrasound and x-ray examination.

Treatment 1. Stones in meatus: Inject paraffin oil, press and pull, or clamp out.

2. Stones in prior urethra: Pull out the stone by urethroscope. Urethrotomy is avoided as possible.

3. Stones in the posterior urethra: Pull into the bladder, and treatment as bladder stone.