EVALUATION OF PT WITH UROLITHIASIS

Naveed MaharResident Urology

JPMC, Karachi

Detailed history

Examination

Metabolic evaluation

Radiological investigations

HISTORYDemographic biodataLife styleOccupationDiet/fluid intakeDrug historySystemic diseaseFamily historyHistory of bowel surgery

Urolithiasis is the disease of males between 20 to 5o

years

OCCUPATIONSedentary occupations predispose to stones more

than manual work

Low activity levels predispose to bone demineralization and hypercalciuria.

Physical activity agitate urine and dislodge crystal aggregates

DIETWater intake

Low fluid intake (<1200 ml/day) predisposes to stone formation

A less energy-dense diet may decrease the incidence of stones.

Vegetarians have decreased incidence of urinary stones High sodium intake is associated with increased urinary

SodiumCalciumPHDecreased urinary citrate

CLIMATESummer is the season of urinary stones and

dehydration is the key factorConcentrated urine has a lower ph, encouraging

cystine and uric acid stone formationExposure to sunlight may also increase endogenous

vitamin D production, leading to hypercalciuria.

FAMILY HISTORYIncidence increases with positive family historyFamilial diseases like

Cystinuria An auto-somal recessive disorder of transmembrane cystine

absorptionRTA

Type 1 or distal RTA: the distal tubule is unable to secret H+

Urinary ph(>5.5) Low urinary citrate Hypercalciuria

Type 2 or proximal RTA: failure of bicarbonate resorption in the proximal tubule.

Type 3: a variant of type 1 RTA Type 4 : is seen in diabetic nephropathy and interstitial renal disease.

PAST HISTORYBowel resectionInflammatory bowel diseaseSystemic diseases i-e

- Gout- Hyperparathyroidism- Sarcoidosis

DRUG HISTORYThe antihypertensive(triamterene) is associated

with urinary calculi Long-term use of antacids containing silica leads to

silicate stones. Protease inhibitors in immunocompromised

patients are associated with radiolucent calculi.Corticosteroids (increase enteric absorption of calcium,

leading to hypercalciuria)Chemotherapeutic agents (breakdown products of

malignant cells leads to hyperuricemia)

PHYSICAL EXAMINATIONPt frequently changes posture to find pain reliefRenal colic is associted with tachycardia, sweating,and nausea Costovertebral angle tenderness may be apparent.An abdominal mass may be palpable in patients with hydronephrosisA thorough abdominal examination to exclude other causes of abdominal

pain. Abdominal tumors, Abdominal aortic aneurysms Herniated lumbar disks Pregnancy

Bladder palpation as urinary retention may present with pain similar to renal colic.

Incarcerated inguinal herniasEpididymorchitis A rectal examination helps exclude other pathologic conditions.

METABOLIC EVALUATIONDepends on the stone type(composition) Stone type is analyzed by

Polarizing microscopyX-ray diffractionInfrared spectroscopy

If stone is not retrievedRadiological appearance radiolucecy/opacityMetabolic evaluation

METABOLIC EVALUATION…Urine pH

pH <6 in a patient with radiolucent stones suggests the presence of uric acid stones.

pH consistently >5.5 suggests distal RTA (~70% calcium phosphate stones)

Evaluation for cystinuria Cyanide-nitroprusside colorimetric test (cystine spot test) Measurement of 24-hour urinary cystine (>250 mg is

diagnostic)Evaluation for RTA

If fasting morning urine ph >5.5, the patient is labeled to have distal RTA.

COMPOSITION & PREVELENCE OF RENAL STONES

PH VALUES AND PREDISPOSITION TO STONE TYPE

RADIOLOGIC INVESTIGATIONS

1. X-ray KUB

2. Ultrasonography

3. Intravenous pyelography

4. Computed tomography

5. Magnetic resonance imaging

PLAIN X-RAY KUB

Not useful if stones areRadiolucentSmaller than 4mmLies over the sacrum or other bony structure.

Bowel gases can obscure its efficacy.Can not differentiate between

StonesCalcified lymph nodesPhleboliths

Sensitivity for diagnosis of stones is 50–70%

X-RAY KUB

US KUB

Usually done to compliment x-ray KUB

Its sensitivity for detecting renal calculi is ~95%

Very sensitive for the diagnosis of obstruction and can

detect radiolucent stones missed on KUB

Its non invasive

May miss small stones and ureteral stones

Particularly important in pregnant pt

U/S KUB

INTRAVENOUS PYELOGRAPHY

Useful for patients with suspected indinavir stonesRequires trained technicianIts an invasive procedure predisposing pts to highly

allergic IV contrastsIts very prolonged procedure takes hoursRequire proper pt preparationNot good investigative modality in acute renal colic

IVP

Films and “phases” of IVPPlain film:

This is used to look for calcification overlying the region of the kidneys, ureters, and bladder.

Nephrogram phase: Film taken immediately following iv contrast The nephrogram is produced by filtered contrast within

the lumen of the proximal convoluted tubulePyelogram phase:

Much denser than the nephrogram phase.As concentrated contrast accumulates in plvicalycel system

IVP

X-RAY IVP 3D

COMPUTED TOMOGRAPHY

Has greater specificity (95%) and sensitivity (97%) for diagnosing ureteric - stones

Noncontrast spiral CT scans are now the imaging modality of choice

Advantages:It is rapid No need for experienced radiologic technicianNo need for intravenous contrast.Uric acid stones are also visualized Disadvantage:Distal ureteral calculi can be confused with phleboliths. These images do not give anatomic details as seen on an IVP (for

example, a bifid collecting system)

MAGNETIC RESONANCE IMAGING

MRI is a poor study to document urinary stone disease.

Clue towards obstruction by diagnosing hydronephrosis