From WikiLectures

Urolithiasis is the presence of stones in the urinary tract - in the renal pelvis (nephro-), ureter (uretero-), bladder (cysto-) or urethra (urethrolithiasis) or stone-forming substances in the renal parenchyma (nephrocalcinosis), in our country is the most common calcium oxalate.

Pathogenesis[edit | edit source]

Crystallization and aggregation[edit | edit source]

The causes include:

  • supersaturation of urine with stone-forming substances (Ca2 +, urates, oxalate), supported by reduced diuresis,
  • urinary incontinence (obstructive uropathy),
  • changes in urine pH (incl. urea-degrading bacteria - Proteus, Pseudomonas, Klebsiella - struvite lithia),
  • lack of inhibitors of crystallization and aggregation (citrates, pyrophosphates, Mg2 +, glycoproteins),
  • some drugs (sulfonamides, antacids).

Cystolithiasis occurs in chronic residual subvesical obstruction or neurogenic bladder.

Concretions are divided into:

  • Contrast X-ray - Ca-oxalate, Ca-phosphate, struvite (MgNH4PO3), cystine,
  • Non-contrasting X-ray - urate, xanthine.

Clinical symptoms[edit | edit source]

Urolithiasis can occur asymptomatically (immobile stones).

Manifesting urolithiasis can be divided according to location into:

  • nephrolithiasis - dull kidney pain (palpation, positive tapottement), ev. how many when blocking the drain,
  • ureterolithiasis - renal colic with vegetative accompaniment, spread according to location (back, inner thigh),
  • cystolithiasis - pain behind the buckle, polakisuria, urgency.

It is often manifested by hematuria and other complications - inflammation (pyelonephritis, cystitis).

Complications[edit | edit source]

Complications include obstruction - renal colic, hydronephrosis, infection to urosepsis, bleeding and renal insufficiency in bilateral disability.

Diagnostics[edit | edit source]

  • Urine: sediment, chemically (incl. Cystine), pH, density, culture (negative with complete blockade).
  • Biochemistry: Ca2 +, phosphates, uricaemia, Astrup (exclusion of RTA - renal acidosis).
  • Examination of concretion:
    • chemical,
    • mineralography - polarizing microscope, X-ray distraction,
    • imaging methods:
      • Ultrasound - identification of stones and dilatation of the urinary tract, so-called acoustic shadows can be seen
      • X-ray (native nephrogram, excretory urography), cystolithiasis cystography, cystoscopy,
      • spiral CT,
      • static renal function study (DMSA).
  • Hypercalcaemia, hypercalciuria, hyperphosphaturia - suspected hyperparathyroidism.
  • Urolithiasis with hypokalemia - suspected RTA - renal acidosis.
  • Hypercalciuria - absorption type (↑ resorption of Ca2 + from the intestine) and renal (↓ reverse resorption in the tubules).
  • Hyperoxaluria - a disorder of intestinal fat resorption (chronic pancreatitis, obstructive jaundice).
  • Hyperuricosuria - myeloproliferative diseases, disorders of purine metabolism, chemotherapy.
  • Hypercystinuria - a congenital disorder of renal cystine transport.
  • Hypocitration - chronic diarrhea, administration of thiazide diuretics.

Metabolic examination in urolithiasis[edit | edit source]

  • Serum: urea, creatinine, uric acid, Na +, K +, Ca2 +, Mg2 +, Cl−, phosphorus, glycemia, total protein, liver tests, cholesterol (LDL, HDL), triglycerides.
  • Urine in 24 hours: volume, urine pH. Wastes in 24 hours: phosphorus, uric acid, creatinine, Na +, K +, Ca2 +, Mg2 +, Cl−, oxalates, citrates, sulphates.
  • Calculations: creatinine clearance, uric acid clearance, Ca2 + / creatinine ratios, Ca2 + / Mg2 +.
  • Proteinuria.
  • Calcium-free diet followed by oral administration of 1000 mg eferv. calcium tablets

Differential diagnostics[edit | edit source]

  • Pain - sudden abdominal event, biliary colic, gynecological disease.
  • Hematuria - tumor, urinary tract infection, coagulopathy (warfarinization).
  • Defect in the filling of the hollow system - urothelial tumor.

Treatment[edit | edit source]

  • Acute renal colic:
    • analgesics, antispasmodics, non-steroidal anti-inflammatory drugs (indomethacin National Office for Drug Control: indomethacin),
    • sufficient hydration,
    • supravesical urine derivation with signs of urinary tract infection or urosepsis.
  • Chronic urolithiasis:
  1. endoscopic methods,
  2. instrumentation - nephrostomy, ureteral probing with extraction or crushing of the stone, cystoscopy with extraction or crushing of the stone - extracorporeal shock wave lithotripsy,
  3. open surgery (in about 1%) - lithotomy (pyelo-, uretero-, cysto-), nephrotomy, nephrectomy,
  4. conservative treatment - symptomatic treatment of colic, metaphylaxis (prevention of recurrences).
  • Concretion extraction - forceps, Zeiss loop, Dormia basket.
  • Concret crushing - mechanically, ultrasound, electrohydraulic, laser, grinding.
    • Indication:
  1. X-ray contrast up to 2 cm made of soft material (weddellite), good anatomical conditions and outflow,
  2. stone over 2 cm, hard (whewellite, struvite, Ca-oxalate, urate), unfavorable anatomy and outflow (stenoses),
  3. Non-contrast X-ray (cannot be targeted by lithotripter), in the lower 2/3 of the ureter,
  4. minor asymptomatic nephrolithiasis, ureterolithiasis up to 4 mm - conservative treatment.
  • Urine pH change:
    • urate stones - alkalization of urine (sodium citrate, potassium citrate),
    • struvite stones - acidification of urine.
  • Metaphylaxis:
  1. non-specific - drinking and diet regime (↑ fluid intake, ↓ Ca2 + and salt intake, meat,…),
  2. specific - according to the composition of stones - most often citrates, in hyperuricaemia and urate lithiasis allopurinol.

Links[edit | edit source]

References[edit | edit source]

  1. KNIGHT, J, D G ASSIMOS a L EASTER, et al. Metabolism of fructose to oxalate and glycolate. Horm Metab Res [online]. 2010, vol. 42, no. 12, s. 868-73, dostupné také z <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3139422/?tool=pubmed>. ISSN 0018-5043 (print), 1439-4286. 
  2. BARTONÍČKOVÁ, K. Urolitiáza. Postgraduální medicína [online]. 2006, roč. -, vol. 2, s. -, dostupné také z <https://zdravi.euro.cz/clanek/postgradualni-medicina/urolitiaza-172263>.