RENAL CALCULUS (STONES)

• Renal calculus more common in males.
• 90% are radioopaque.

 ETIOLOGY-

1. Infection-

• E. Coli, Proteus, Pseudomonas, Klebsiella- recurrent UTI

    2. Hot climate-

• Formation of calcium oxalate stones.

    3. Dietary factors-

• Vitamin A deficiency
• Diet rich in red meat, fish, eggs- aciduria
• Diet rich in calcium- tomato, milk, spinach- calcium oxalate stones

    4. Metabolic cause-

• Hyperparathyroidism- hypercalcinosis and pelvic stones
• Gout- uric acid stone
• Sarcodosis

    5. Immobilisation-

• Paraplegic patient- calcium oxalate stones

     6. Decrease urinary citrate

     7. Inadequate urinary drainage- horse shoe unascended kidney

     8. Randall’s plaque

     9. Carr’s postulates also called as microliths

    10. Cystinuria (autosomal recessive)

    11. Medullary sponge kidney

    12. Renal tubular acidosis – calcium phosphate stone

    13. Hypomagnesuria

    14. Topiramate can be dangerous as it may cause renal stone formation if used along with carbonic anhydrase inhibitors, potassium sparing diuretics                  cause renal stones is Triamterene

 

 

 

 STAGES OF STONE FORMATION-

a) Supersaturation

b) Nucleus formation

c) Crystallization

d) Aggregation

e) Matrix formation

f) Stone

TYPES-

1. Oxalate stones (75%)

• MC type of kidney stone
• Also called as mulberry calculi
• It is brown in color, irregular having sharp projection.
• Oxalate stone is hard and single.
• Risk factors are hypercalciuria, hypercalcemia, hyperoxaluria.
• Calculus oxalate dihydrate stone shows envelope and Ca oxalate monohydrate dumbbell.
• Crystals in urine
• Hardest renal stones  
• Haematuria and occurs in infected urine
• Visualised in plain X- ray, KUB.

 

    2. Phosphate stone (10- 15%)

• Consists triple phosphate of calcium, magnesium and ammonium.
• Commonly in renal failure.
• In alkaline urine, it enlarges and grows within major and minor calcyces and forms Staghorn calculus.
• Produces recurrent UTI and haematuria
• They are radioopaque

 

     3. Uric acid stones (5%)

• Multiple, small, hexagonal, faceted, yellow coloured.
• Pure uric acid are radiolucent
• Occurs in acidic urine
• Seen in gout, hyperuricosuria, altered purine metabolism.
• Best treatment- lithotripsy

 

     4. Cystine Stones (2%)

• Occurs in cystinuria due to defective absorption of cystine from renal tubules (autosomal recessive condition)
• It is hexagonal in shape.
• Occurs only in acidic urine
• Seen in young girls at puberty.
• Radioopqaue as it contains sulphur.
• Increase urine volume (high fluid intake)
• Alkalinization of urine
• Penicillamine and tiopronin undergoes sulfhydryl-disulphide exchange with cystine to form mixed disulphides, since these disulphides are much soluble than cystine, pharmacologic therapy can prevent and promote dissolution of calculi

 

     5. Xanthine stones-

• Very rare, smooth, brick red in color.
• Due to deficiency of xanthine oxidase enzyme
• Radiolucent

 

    6. Struvite stones

• Compound of magnesium, ammoniumphosphate mixed with carbonate.
• Occurs due to proteus, Klebsiella
• Colorless, prism like crystals (coffin lids)

 CLINICAL FEATURES-

1. Renal pain-

• Located over renal angle, hypochondrium, lumbar region.
• Costovertebral pain
• Nausea and vomiting

1. Haematuria
2. Pyuria
3. Fever
4. Tenderness in renal angle
5. Recurrent UTI

 

INVESTIGATIONS-

1. Plain X- ray KUB

• 90% stones are radioopque

     2. USG-

• Presence of stone, size and location

     3. IVP-

• Locate stone exactly and assess renal failure
• Hydronephrosis and hydroureterosis can be seen.

    4. CT scan-

• Accurate detection of causes of abdominal colic

 TREATMENT-

1. Non operative treatment-

a) Small stone >5 mm in size- IV hydration followed by IV frusemide

b) Extracorpeal shock waves lithotripsy (ESWL)-

• For renal calculus
• After cystoscopy, a ureteric stent (double J stent) into ureter placed for large renal stones.
• Cannot fragment cysteine stone due to crystal lattice
• After fragment, laser lithotripsy is used (holmium- YAG laser most effective)
• Laser lithotripsy can fragment all stones.

 

    2. Operative treatment-

a) PCNL (percutaneous nephrolithotomy)

• For stones more than 2. 5 cm in size
• Multiple stones
• Not responding to ESWL
• Cysteine stones

b) Pyelithotomy- stones in renal pelvisgo

c) Nephrolithotomy- complex calculus

d) Partial nephrectomy- stones in lower most calyx

Don’t Forget to Solve all the previous Year Question asked on RENAL CALCULUS
Click Here to Start Quiz