RENAL STONE DISEASE

ANALYSIS OF STONES ______________________________ Oxalate504 (56.1%) Triple phosphate237 (26.4%) Phosphate119 (13.4%) Uric acid 38 (4.2%) ______________________________ Total 898 (100%)

AGE DISTRIBUTION OF OXALATE STONES

FORMATION OF STONES Urine pH/infectionRenal damageCalcium/oxalate Tissue debris Anatomical stasis Fixed particles inhibitors Aggregation Stone formation

FORMATION OF STONES 1.Calcium -a) hypercalcaemia b) hyperparathyroidism c) hypercalciuria 2.Oxalate - G1, hyperoxalaturia 3.Cystine 4.Uric Acid 5.Infection - Urea-splitting organisms 6.Congenital / metabolic defects: - medullary spone kidney - renal tubular acidosis

CLINICAL PRESENTATION 1.Flank/loin pain, colicky + radiation - haematuria - nausea and vomiting - chills/fever/frequency, if infected 2.Loin tenderness 3.Bilateral stones : renal failure

INVESTIGATIONS 1.IVU and DTPA 2. Serum creatinine calcium 3. Urine pH 4.24-hour urine 5.Urine cultures 6.Stone analysis

METABOLIC ABNORMALITIES (N = 392) Hypercalciuria28% Hyperoxaluria16% Hyperuricosuria14% Cystinuria0.5% Hyperparathyroidism1% Primary oxalosis0.25% Renal tubular acidosis0.25%

INDICATIONS FOR TREATMENT Presence of symptoms and / or obstructive uropathy in a functioning kidney

Treatment of Renal Stones Four Options1) conservative 2) non-invasive:ESWL 3) minimal invasive : PCNL, URS 4) open surgery New technology:  morbidity,  hospital stay,  invasiveness

Electromagnetic Shockwave

MANAGEMENT OF RENAL CALCULI by ESWL < 2cm in diameter and/or surface area < 500 mm 2 Treatment : ESWL monotherapy > 2cm in diameter and/or surface area > 500 mm 2 Treatment : PCNL +/- ESWL Combination therapy

MANAGEMENT OF RENAL CALCULI by ESWL > 2cm in diameter and/or surface area > 500 mm J Stents + ESWL with repeated treatments required

ESWL for Staghorn Stones PCNL + ESWL as main option ESWL monotherapy is discouraged Open surgery has a place for large complete staghorn calculi

Contra-indications to the Use of ESWL Absolute contra-indications Pregnancy Untreated urinary tract infection Distal obstruction to the stone that cannot be bypassed by a stent Untreated bleeding diatheses Non-functioning kidney

PCNL

Percutaneous Nephroscope and Lithoclast

PCNL

Results of Percutaneous Nephrolithotripsy PCNL Indications : High stone burden or failed ESWL Success:Stones free82% Insignificant fragments15% Failure:Stones > 4cm in diameter3%

Traumatic AV Fistula after PCNL

MANAGEMENT OF URETERIC STONES -Stones < 0.5 cm in diameter doesn’t pass spontaneously 4 to 6 weeks and /or causing symptoms : ESWL monotherapy -Stones > 0.5 cm in diameter & < 1 cm in diameter : ESWL monotherapy

MANAGEMENT OF URETERIC STONES Stones > 1 cm in diameter : trial of ESWL monotherapy Patient counselled: 1.Repeat session may be necessary 2.URS/PCNL/ureterolithotomy

RESULTS OF URETROSCOPIC LITHOTRIPSY (URS) Achieved stone free status = 85% to 90% Failures: 1.Access problems 2.Stone migration Flexible URS for upper third ureteric calculi especially in the male

Ureteric stone suitable for ESWL

URS with Guide wire

OPEN STONE SURGERY 2% incidence of all stone treatments Indications: 1.Complex stone burden38% 2.Non-functioning kidneys20% 3.Failure of MIS16% 4.Others26%

Recurrent Rate 75% - 10 Years 100% - 20 Years (Williams 1963)

PREVENTION OF STONES 1.Treatment of causes 2.Dietary manipulations 3.Medications - indication duration

DIETARY ADVICE 1.Hydration 2.Avoid oxalate-rich food 3.Avoid calcium-rich food ? 4.Avoid refined carbohydrates 5.Increase crude fibres

MEDICATIONS 1.Thiazides 2.Allopurinol 3.Antibiotics 4.Sodium bicarbonate 5.Potassium citrate 6.Magnesium salts 7.Pyridoxine

Cystine Stone 1% of stone population Autosomal recessive Round stones in calyces Large staghorn stones Hexagonal crystals

Medical Treatment - Cystine Volume at 2.5 l/day Increase pH to > 7.0 Decrease dietary protein D-penicillamine, thiola Side-effects : marrow / nephrotic

Indinavir Stone Protease inhibitor for HIV Not radio-opaque Cannot see on CT scan Poor solubility Prophylaxis – acidification of urine

Congenital Oxalosis Autosomal recessive Dystrophic calcifications in blood vessels Multiple nephrocalcinosis in young Early renal failure Disease recur in transplanted kidney Treatment with high dose pyridoxine

Nanobacteria Small size nm Atypical, cytotoxic, filterable 0.22 ųm Slow doubling time – 3 days Present in 90% human stones? Act as the nidus Sensitive to tetracycline T Jarrett 1999