Urinary Stone disease is having bad habit of recurrence. Its painful and destructive disease. A thorough 24 hrs Urine Metabolic profile and Stone analysis can found cause of stone disease in 90% cases. This guides clinicians to focally treat patient and prevent stone recurrance.

1. Dr. Sanjeev MehtaDr. Sanjeev Mehta MDMD
www.urolab.net
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Metabolic Work-up of Urinary
Stone Disease and its
significance.

2. Stone disease: issues
High Incidence
Recurrence
Underlying
abnormality
Research
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3. Stone Formation : Supersaturation
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Super saturation drives crystal
formation and growth

4. Stone disease treatment ?
Objective to treat disease ;
• To make Patient free of disease.
• To stop recurrence of same disease.
Does current therapy address recurrence
issue ?
Right approach and treatment isRight approach and treatment is
possible once exact cause is known.possible once exact cause is known.
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5. Work-up : Series of tests
1.Identify treatable metabolic abnormality
2.Identify underlying medical disease that
predisposes to stone formation.
3.Outline a treatment plan.
STONE ANALYSIS.
24 HRS URINE METABOLIC PROFILE
New advances in Stone analysis, Blood and Urinary
Chemical analysis can find out 90-95% cause.
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6. Six myths
1. All stones are Calcium stones.
2. Composition can be diagnosed by looking to
stone.
3. Doesn’t affect treatment /prognosis.
4. Once stone analysis done, no need to repeat.
5. Expensive.
6. Small fragments can’t be analysed.
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7. • “On both Clinical and Economic grounds,
evidence based medical intervention is the
only approach likely to make a significant
impact on the incidence, and on recurrence
of disease.”*
• Targeted medical prophylaxis requires
reliable information on stone type.
*Ref: Ann Clin biochem 2004;41:91-97
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Stone Evaluation : Why ?

8. Stone analysis
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9. Renal Stone Analysis
• Essential step in the examination and initial
treatment of Urolithiasis.
• Composition yields fundamental information
of pathogenesis of disease like ;
- Metabolic abnormality.
- Etiological diagnosis .
- Presence of infection.
- Possible artifacts.
- Drug metabolism.Uro Lab. 9

10. Actually up to 100 different chemical
compounds are found in urinary calculi.
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11. Fractured Stone...
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12. INTEGRETED
ANALYSIS;
Mixed Stone
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13. Significance of Stone analysis
• Exact composition gives important clue as to
how Stone formed.
• Information may not available from any other
type of work-up.
• Identify factors leading to clinical events.
• Identify Risk factors.
• Subsequent analysis differ in 21% cases,
making it to analyse with every episode
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14. Significance of Stone analysis
• Three categories :
1.Composition and hardness of Renal Stones.
2.Composition and its predictive value.
3.Composition and related metabolic
abnormalities.
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15. Hardness Factor of Stone
Calcium Oxalate Dihydrate 1.0
Calcium Oxalate Monohydrate 1.3
Hydroxy-peptite 1.1
Brushite 2.2
Uric Acid/ Urate 1.0
Cystine 2.4
Carbonate Apatite 1.3
Struvite 1.0
Mixed Stone 1.0
* Ringden I, Scand J Urol Nephrol.2007;41(4):316-23
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16. Stone analysis: Exclusive and only way :
• Cystine
• Xenthine
• 2,8, - dihydroxyademine
• Drugs
- Sulfadiazine-
- Atazanavir
- Triemterene , anti viral drug
• Artefacts
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17. Stones: Specific treatment
• Uric acid stones ; treatable if pure
• Cystine stones.
• Struvite stones .
• Xenthine stones.
• Drug stones.
• 2,8 dihydroxyadenine stones.
• Silicate stone
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18. Screen for systemic diseases
• Stone is first manifestation of numerous
disorders.
• Hyperparathyroidism
• Primary hyperoxaluria.
• Distal renal tubular acidosis
• Medullary sponge kidney.
• Crohn's disease, Bariatric surgery.
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19. Calcium Stones
• Commonest ; Pure or mixed.
• Mixed stones can have more than two
components
• Each component gives clue about cause
• Phosphate component, more challenging to
treat.
• With 24 hrs Urine metabolic profile; best
results
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20. Idiopathic Calcium stones
Calcium Oxalate
Monohydrate
Calcium Oxalate Dihydrate
Hyper-oxaluria 88% Hyper-calciuria 85%
Hypo magnesuria Hypocitruria
Acidic Urine Alkaline Urine
Low Urine volume Low Urine Volume
Hard ++ Hard +
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21. Ammonium Urate
• Calcium oxalate – containing calculi, may
start due to hyperuricosuria.
• Elders : associated with infection.
• Children : May also form as result of
hyperuricosuria, but NO urinary tract
infection.
• Rare in pure form (0.03%)
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22. Phosphate Stones
• 12 to 20%
• Struvite : Infection.
• Carbonate Apatite : Not always infection.
• Brushite : Not associated with infection
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23. Phosphate Stones; Carbonate
apatite
• CaOx stones contain CaPh component due to
Randall’s plaque.
• With COD raises suspicion of Pri.
Hyperparathyroidism.
• Higher apatite suggests RTA
• Have high pH. ? Infection
• Infection; presence of Struvite confirms
; carbonate > 15%
HCL test. Uro Lab. 23

24. Initial nucleation process could be related to
another pathology
mixed with Magnesium ammonium phosphate.
• Cystine in initial analysis : secondary UTI
• Cystine or uric acid initially ; over enthusiastic
alkali therapy
• Uric acid to xenthine due to allopurinol
therapy.
Composition can change !
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25. 24 hrs Urine metabolic profile ;
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26. 24 hrs Urine Metabolic Test profile
• Oxalate
• Citrate
• Uric acid
• Sodium
• Potassium
• Magnesium
• Phosphorus
• Creatinine
• pH
• Total volume
• Super-saturation
- Calcium oxalate
- Calcium Phosphate
-Uric Acid.
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27. Uro Lab. 27

28. Prevention can be achieved!
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29. Prevention: five steps
1. Know your crystals
2. Obtain proper blood and 24 hrs Urine
measurements
3. Lower by half the Supersaturation.
4. Obtain more 24 hrs Urines if new stone
continue
5. Follow up every year thereafter even if free
of new stones.
Fredric Co;http://kidneystones.uchicago.edu/Uro Lab. 29

30. Thank You !
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