STONE DISEASE ( Brief Overview ) Dr. Sunil Shroff, MS, FRCS (UK), D.Urol (Lond.), Professor & HOD, Dept. of Urology, Sri Ramachandra Medical College &

STONE DISEASE

( Brief Overview )

Dr. Sunil Shroff, MS, FRCS (UK), D.Urol (Lond.),

Professor & HOD, Dept. of Urology,

Sri Ramachandra Medical College & Research Institution

Consultant Urologist & Renal Transplant Surgeon,

Sri Ramachandra Hospital, Porur, Madras.

COMPARATIVE INCIDENCES OF FORMS OF URINARY LITHIASIS

Stone analysis in Percentage

Form of Lithiasis India USA Japan UK

Pure Calcium Oxalate 86.1 33 17.4 39.4

Mixed Calcium Oxalate and 4.9 34 50.8 20.2

Phosphate

Magnesium Ammonium 2.7 15 17.4 15.4

Phosphate (Struvite )

Uric Acid 1.2 8.0 4.4 8.0

Cystine 0.4 3.0 1.0 2.8

Cause of Stone Disease

• Supersaturation of urine is the key to stone formation

• Intermittent supersaturation - Dehydration

• Crystal aggregation

• Anatomic Abnormailities – PUJ , MSK

• Bacterial Infection

• Defects in transport of Calcium and Oxalate by Renal

epithelia

E.Coli infection increases matrix content in urine . Proteus makes urine alkaline

Inhibitors & Promoters of Stone Formation in Urine

INHIBITORSInhibits crystal Growth -

• Citrate – complexes with Ca

• Magnesium – complexes with oxalates

• Pyrphosphate - complexes with Ca

• Zinc

Inhibits crystal Aggregation

• Glycosaminoglycans

• Nephrocalcin

• Tamm- Horsfall Protein

PROMOTERS• Bacterial Infection• Matrix • Anatomic Abnormalities – PUJ

obst., MSK • Altered Ca and oxalate transport

in renal epithelia • Prolonged immobilisation• Increased uric acid levels I.e

taking increased purine subs– promotes crystalisation of Ca and oxalate

• ?? Nanobacteria – seen in 97% of renal stones

SOME DISEASES ASSOCIATED WITH HYPERCALCAEMIA & HYPERCALCIURIA

Hyperparathyroidism Leukemia

Sarcoidosis Lymphoma

Multiple myeloma Myxedema

Hyperthyroidism Adrenal Insufficiency

Metastatic Malig. Neoplasm's Vit. D Intoxication

TYPES OF KIDNEY / URETER STONES

• OXALATE (CALCIUM OXALATE)

• PHOSPHATE

• URIC ACID & URATE

• CYSTINE

Uncommon Stones

XANTHINE STONES

– (Autosomal Recessive . Def of Xanthine Oxidase leading to Xanthinuria)

DIHYDROXYADENINE STONE

– ( Def. of enzyme adenine phospo ribosyl transferase )

SlLICATE STONES

– Rare in humans ( excess intake of Antacid with Mg Trisilicate. Mostly in cattle due to ingestion of Sand )

MATRIX

- Infection by Proteus - Radiolucent (all calculi have some amt ( 3%) of matrix but matrix calculus has 65% Matrix content in calculi)

Uncommon Stones

TRIAMTERENE

– Anti-hypertensive used with hydroclorothiazide – spare Potassium.

Mostly found as a nucleus in Ca oxalate or uric acid calculus

Indinavir Stones

- Drug to treat AIDS (4 to13%)

Ephedrine or Guifenesin

– Cough medicine - Radiolucent

Stones – Chemical Constituents

• Whewelite – Calcium Oxalate Monohydrate – CaC2O4-H2O

• Weddelite - Calcium Oxalate dihydrate – CaC2O4-2H2O

• Brushite – Calcium Hydrogen phosphate dihydrate – CaHPO4 2H2O

• Whitlockite - TriCalcium Phosphate – Ca2(PO4)2

• Struvite – Magnesium Ammonium hexahydrate – MgNH4PO4-6H2O

DD of Radiolucent filling defect on IVU in Ureter or Kidney

Must Know

• Uric Acid Calculus• Matrix Calculus• Sloughed Papilla• Blood Clots• TCC • Renal Cysts• Vascular Lesions

Know For Brownie Points

• Xanthine Calculus• Hydroxyadenine Calculus• Ephederine Calculus• Infection due to gas forming

Org.• Fungal Ball• Tuberculoma• Malacoplakia• Hypertrophied Papilla• Renal pseudo-tumour

OXALATE (CALCIUM OXALATE)

• ALSO CALLED MULBERRY STONE

• COVERED WITH SHARP PROJECTIONS

• SHARP MAKES KIDNEY BLEED (HAEMATURIA)

• VERY HARD

• RADIO - OPAQUE

Under microscope looks like Hourglass or Dumbbell shape if monohydrate and Like an Envelope if Dihydrate

PHOSPHATE STONE

• USUALLY CALCIUM PHOSPHATE

• SOMETIMES CALCIUM MAGNESIUM AMMONIUM

PHOSPHATE OR TRIPLE PHOSPHATE

• SMOOTH MINIMUM SYMPTOMS

• DIRTY WHITE

• RADIO - OPAQUE

Calcium Phosphate also called ‘Brushite’ appears like Needle shape under microscope

PHOSPHATE STONES

IN ALKALINE URINE

ENLARGES RAPIDLY

TAKE SHAPE OF CALYCES

STAGHORN

Struvite can form Stag-horn and appear like coffin lid under microscope

CALCIUM PHOSPHATE STONES

• Hyperparathyroidism Ca P

• Renal Tubular Acidosis K CO2

• Medullary Sponge Kidney -

PTH Hormone Promotes renal production of 1-25-dihyroxycholecalciferol – active Vit.D and also

increases absorption of Calcium and decreases Phosphorus absorption from Kidneys

URIC ACID & URATE STONE

• HARD & SMOOTH

• MULTIPLE

• YELLOW OR RED-BROWN

• RADIO - LUCENT (USE ULTRASOUND)

Under microscope appear like irregular plates or rosettes

pKa of uric acid 5.75 – at this pH 50% of uric acid insoluble.If pH falls further - uric acid more insoluble

CYSTINE STONE• AUTOSOMAL RECESIVE DISORDER

• USUALLY IN YOUNG GIRLS

• DUE TO CYSTINURIA -

• CYSTINE NOT ABSORBED BY TUBULES

• MULTIPLE

• SOFT OR HARD – can form stag-horns

• PINK OR YELLOW

• RADIO-OPAQUE

Under microscope appears like hexagonal or benezene ring – ask for first morning sample

CYSTINE STONE - Management

• High Fluid Intake and Alkalanise Urine – dissolve most of

the smaller cystine stones

• D-Pencillamine or MPG (Mercaptopropionylglycine) binds

to cystine that is soluble in urine

• Side effects of Pencillamine restricts it use – Allergic

rashes, GI problems- Nausea, Vomiting, Diarrhoea

• MPG better tolerated

• Large obstructive stones – Surgery required first

Cyanide Nitroprusside Calorimeteric Test for detecting Cystinuria. If positive do amino acid chromatography

pKa of cystine is 8.3, hence alkalinisisation above pH7.5 helps to dissolve the stones

Surgical Conditions and Stone Disease

• Regional ileitis and Ileal Bypass Surgery for eg Obesity can lead to increase oxalate absorption and stone ds

• ileostomies - In Chr. Diarrhoea with– Bicabonate loss – systemic acidosis and acidic urine – increases risk of Uric Acid stones

HISTORY

A. IS PATIENT DRINKING ENOUGH ?

B. PROFESSION

C. ENQUIRE ABOUT UTI STONES

D. FAMILY HISTORY

E. LONG ILLNESS BEDRIDDEN STONES

MANAGEMENT OF STONES

HISTORY :

A. FIND OUT IF DRINKING ENOUGH LIQUIDS

(NOT DRINKING ENOUGH IMPORTANT CAUSE

OF STONE FORMATION & GROWTH)

Urinary supersaturation of salts in concentrated urineAtleast drink 3 lits to avoid stone formation

HISTORY (Cont...)

B. ASK ABOUT THEIR PROFESSION

DEHYDRATION STONES CAN FORM e.g.

• MARATHON NEAR A FURNACE,

• BRICK - LAYER, LABOURERS & WEAVERS

• TRUCK & BUS DRIVERS

C. ENQUIRE ABOUT UTI STONES

D. FAMILY HISTORY

E. LONG ILLNESS BEDRIDDEN STONES

HISTORY (Cont...)

Zero Gravity state – astronauts on long space flights more prone to stones

CLINICAL FEATURES

1. PAIN IN 75 % OF THE CASES

“RENAL COLIC” IF SEVERE AND ACUTE

A) KIDNEY STONE

FIXED PAIN IN THE LOIN

B) URETERIC STONE

PAIN RADIATES LOIN TO GROIN

Both Stomach & Kidney supplied by celiac ganglion hence Nausea & vomiting common in renal colic

CLINICAL FEATURES (Contd....)

2) HAEMATURIA

• CAN BE FRANK

• OR ONLY FOUND ON DIP - STICK OR LAB.

3) PYURIA - IF INFECTION CAN HAVE PUS IN URINE

ON EXAMINATION

1. ACUTE PRESENTATION

• ABDOMEN TENSE AND RIGID

• TENDERNESS PRESENT IN THE LOIN

2. IN ROUTINE PRESENTATION

• NO FINDINGS IN ABDOMEN

INVESTIGATIONS

1. FULL BLOOD COUNT TO CHECK FOR

ANAEMIA IF GOING FOR SURGERY

2. SERUM ELECTROLYTES PLUS UREA /

CREATININE / CALCIUM / URIC ACID /

PHOSPHATE

INVESTIGATIONS (Cont...)

3. 24-HOURS URINE FOR ELECTROLYTES

(Only if recurrent stone former)

CALCIUM / OXALATE / URIC ACID /

CYSTINE / CITRATE

INVESTIGATIONS (Cont...)

4. PLAIN KUB X-RAY OF ABDOMEN (Mandatory)

5. IVU OR IVP (INTRA VENOUS UROGRAM)

6. ULTRASOUND (Mandatory)

INVESTIGATIONS

IVU OR IVP (INTRA VENOUS UROGRAM)• Not Mandatory• 1in 40,000 patients die due to anaphylactic reaction to

contrast• Useful for radio-lucent stones & to detect

Congenital Anomalies in Urinary tracts

INVESTIGATIONS (Cont...)

7. CT –

TO LOOK AT UNUSUAL ANATOMY OF THE KIDNEY

To differentiate cause of acute colic – stone or anuria

Suspected due to stone disease

8. DMSA OR DTPA OR MAG3 RENOGRAM - TO STUDY FUNCTION OF

EACH KIDNEY.

Bilateral Ureteric Calculus in a patient presenting with Anuria Bilateral Ureteric Calculus in a patient presenting with Anuria

Helical or Spiral CT provides 3D reconstruction. Helical refers to path the X ray follows on Gantry. These are rapidly performed and do not require contrast agents for reconstruction.

MANAGEMENT OF UROLITHIASIS

• Non-invasive approach to urinary calculas-HALLMARK of last 20 yrs.

• Lithotripters –

1.Extra Corporeal Shock wave

2.Intra Corporeal

• Better fiber optics – Miniturisation of Telescopes • Accessories - Innovative variety

Modern Management of Urolithiasis

• ESWL• Ureterorenoscopy• Percutaneous Nephrolithotomy• Laparoscopic Approach to stones

Open Ureterolithotomy, Pyelolithotomy or Nephropyelolithotomy is required in less than 1 to 2% of modern stone management

TREATMENT (IDEALLY)

MAJORITY : 80 TO 85 % of all stones can be treated by -

EXTRA - CORPOREAL SHOCK WAVE LITHOTRIPSY (ESWL)

MINORITY : 15 TO 20 % SHOULD NEED MINIMALLY

INVASIVE SURGERY (PCNL / URETEROSCOPY)

(LESS THAN 1 % SHOULD NEED OPEN SURGERY)

EXTRA - CORPOREAL SHOCK WAVE LITHOTRIPSY(ESWL)

SHOCK WAVES GENERATED UNDER WATER CAN

TRAVEL THROUGH BODY WITHOUT ANY APPRECIABLE

LOSS OF ENERGY. WHEN THEY ENCOUNTER STONES

THE CHANGES IN DENSITY CAUSES ENERGY TO BE

ABSORBED AND REFLECTED BY THE STONE & THIS

RESULTS IN FRAGMENTATION OF THE STONES.

ESWL – For Urinary Tract CalculusESWL – For Urinary Tract Calculus

ESWL- FOUR MAIN ELEMENTS

1. ENERGY SOURCE

2. FOCUSING DEVICE

3. COUPLING DEVICE

4. LOCALIZATION DEVICE

ESWL

Absolute Contra-indication-Pregnancy

Relative Contra-Indications for ESWL –

• Renal Colic• Urinary obstruction • Infection• Declining Renal Function• Significant Hematuria

COUPLING DEVICE

“WATER BATH”

“WATER FILLED CUSHION”

(KEEP PATIENT’S DRY)

ESWL-HISTORY

1963-EXPERIMENTS WITH “ SHORT WAVES” IN W.GERMANY BY PHYSICISTS AT DONIER SYSTEMS LTD

1980-DORNIER HUMAN MODEL ( HM-3)

LITHOTRIPTER ARRIVED ON MARKET

(STILL GOLD STANDARD WHEN COMPARING RESULTS WITH NEW MEASUREMENTS

ESWL & STAGHORNS

• Dornier HM-3 Monotherapy for STAGSHORNS -

30% Stone Free Rate (In Dilated Collecting System )• PCNL has higher overall Success• Combination of PCNL & ESWL can give a

stone free rates of 90% For ALL STONES IN THE KIDNEY

COMPRESSION-TENSILE WAVE CAUSES:

“Implosion” Rather than “Explosion”

ESWL & URETERIC CALCULI

• For fragmentation fluid medium around stone necessary

• If stones impacted fragmentation may not occur

• “PUSH & BANG”-success Marginally HIGHER THAN “in situ ESWL”

• Trial of “in situ ESWL” – first choice • “In situ ESWL” FAILS- “Rescue procedure”

ESWL COMPLICATIONS

• Haematuria – is quite common ( short term antibiotics Recommended )

• Incomplete stone Fragmentation & Obstruction• “Stienstrasse” ( stone street ) usually due to a

large “ Leading fragment”

( Stents Recommended prior to ESWL for Calculi > 1.5 cm )

DESIGN BASIC LITHOTRIPSY

Renal Lithiasis Blood Pressure Study ( Patients treated 1984-1986

Dallus Study)

First Follow Up Second Follow Up

1988 1990

No.Pts Annualized Rate No.Pts Annualized Rate of Hypertension of Hypertension

ESWL 771 2.5% 590 2.1%

non-ESWL 195 3.8% 155 1.6%

Total 966 745

Basic Principles of

“SHOCK WAVE”

Lithotripsy

FRAGMENTATION BY SHOCK WAVES

ON COLLISION OF “ SHOCK WAVES” WITH CALCULI-

• ON FRONT SURFACE – COMPRESIVE FORCES• ON BACK SURFACE OF THE STONE-

REFLECTION OF COMPRESSION PULSE CREATES NEGATIVE OR TENSILE WAVE THAT TRAVEL BACK WARD THROUGH CALCULI

• ONCE TENSILE FORCE EXCEEDS “ COHESIVE STRENGTH” OF CALCULI- FRAGMENTATION OCCURS

ESWL – SPARK GAP/ EHL

• Electro-hydraulic Generator Located at Base of Water Bath

• Produces Shock wave by Electric Spark Gap of 15,000 to 25,000 Volts Lasting 1 Sec

• High Voltage Spark Discharge Rapidly-

evaporates Water & Generators A “Shock Wave” by expanding Sarrounding Liquid

Mechanism of Stone Fragmentation by ESWL

• On Front Surface – Compresive or positive Forces• On Back Surface Of The Stone-

Reflection Of Compression Pulse Creates Negative Or Tensile Wave That Travel Back Ward Through Calculi

• Once Tensile Force Exceeds “ Cohesive Strength” Of Calculi- Fragmentation Occurs

• Cavitation – Small air bubbles

Steinstrasse ( or Stone Street) – Post ESWL

Diet & Fluid Advice

• High Fluid Intake

• Restrict Salt (Na)

• Oxalate Restrict

• Avoid high intake of Purine food

• Increased citrus fruits may help

• If hypercalciuria restrict Ca intake

Role of Potassium Citrate in preventing Cal Oxalate stone ds – KCit lowers

urinary calcium whereas Na Citrate does not lower Calcium due to Sodium load

LIQUIDS

Moderate Amounts : High Amounts :

Apple Juice Cocoa

Beer Fresh Tea

Coffee

Cola

FOODS :

Almonds, Asparagus, Cashew Nuts, Currants, Greens,

Plums, Raspberries, Spinach

HIPPOCRATIC OATH :

“I Will not cut, even for the stone, but leave such

procedures for the practitioners of the craft”