Management

Acute Renal Colic

• Aggressive intravenous fluid hydration (if the patient is dehydrated and unable to take fluid orally)
• Parenteral analgesic
• There is no benefit from using smooth muscle relaxants such as nifedipine

Medical Treatment of Nephrolithiasis

• General conservative measures
  • High fluid intake of at least 8 to 10 (10 oz) glasses per day
  • Relatively low animal protein diet (0.8 to 1.0 g/kg/d)
  • A low-sodium diet (2 to 3 g/d or 80 to 100 mEq/d)
  • Dietary calcium restrictions
  • Avoid stone provoking drugs i.e., Calcitrol, calcium supplements, loop diuretics, Probenicid
• Medical therapy of different stone types
  • Calcium stones
    • Absorptive hypercalciuria type L Thiazide diuretics
    • Absorptive hypercalcemia type II
    • Absorptive hypercalciuria type III
    • Renal hypercalciuria. Thiazide
    • Hyperuricosuric calcium oxalate nephrolithiasis
    • Hypocitrauria
    • Enteric hyperoxaluria. i
      
      Phase I
      • Treat underlying disease
      • Increase fluid intake
      • Low dietary fat (50 g/d) and oxalate
      • Calcium supplementation
      • Cholestyramine
      
      Phase II
      • Added to phase I after it has been unsuccessful
      • Potassium citrate
      • Magnesium supplement with magnesium gluconate
      • Allopurinol (if the stones contain uric acid)
      • Pyridoxine (Vitamin 136)
      • Primary hyperoxaluria. Pyridoxine (vitamin 136)
  • Uric acid stones
    • Increase fluid intake
    • Decrease dietary animal protein
    • Decrease dietary purine
    • Urinary alkalinization with potassium citrate
    • Acetazolamide (Diamox)
    • Allopurinol
  • Cystine stones
    • If urine cystine is below 500 mg/L increase fluid intake to maintain urine output more than 3 L a day. Urinary alkalinization with potassium citrate is used to keep urine pH 7.0 to 7.5.
    • If urine cystine is above 500 mg/L or the above measures are ineffective, D-penicillamine, Tiopronin (Thiola, mercaptopropionylglycine) or Captopril

Non-medical Management

• Therapeutic modalities:
  • Extracorporeal shock wave lithotripsy (ESWL)
  • Percutaneous nephrostolithotomy (PCNL)
  • Rigid and flexible ureteroscopy (URS)
  • Combination treatment
  • Open surgical approaches
• Factors influencing therapeutic choice
  • Stone burden
  • Stone location
  • Stone composition
  • Extraurinary factors, i.e., presence of retroperitoneal masses, bony abnormalities such as scoliosis, coagulation abnormalities, pregnancy, cardiac pacemakers, and extra-renal vascular calcifications, etc.)
• Shock wave lithotripsy
  • Lithotripsy devices share four main features
    • Energy source (electrohydraulic, piezoelectric, electromagnetic)
    • Coupling mechanism (water bath or water cushion and gel)
    • Focusing device (ellipsoid, spherical disc, acoustic lens)
    • Stone localization (fluoroscopy, ultrasound)
  • Contraindications of ESWL
    • Absolute: pregnancy, bleeding diathesis, and obstruction below the level of the stone
    • Relative: calcified arteries and/or aneurysms and cardiac pacemaker (pacemaker should be reprogrammed)
  • Complications of ESWL
    • Renal colic due to the passage of stone fragments or obstruction, steinstrasse and incomplete fragmentation
    • Skin bruising, subcapsular and perinephric hemorrhage, pancreatitis, hearing loss, and urosepsis.
  • Efficacy of ESWL
    • 78 to 91 percent success rate for renal stones less than 2 cm
    • 80 percent success rate for upper and middle pole calyceal calculi
    • 60 percent with lower pole calyceal calculi.
    • 62 to 90 percent success rate is found for nonimpacted upper ureteric calculi
    • 54 to 80 percent success rate for mid-ureteral stones
  • Adjunctive modalities
    • Stents are used with stone burdens greater than 1.5 cm and to increase the treatment success with upper or mid-ureteral calculi
  • Combined therapy. Large stone burdens or staghorn calculi often require initial debulking with percutaneous procedures followed by ESWL for residual stones.
• Percutaneous nephrolithotomy
  • Indications
    • Staghorn calculi
    • Large renal stone burden
    • Large lower pole renal calculi
    • Cystine calculi
    • Abnormalities of renal and upper tract anatomy
    • Abnormalities of patient anatomy
    • Shock wave lithotripsy and ureteroscopy failures
    • Nephrolithiasis in transplanted kidney
  • Contraindications:
    • Uncontrolled bleeding diathesis
    • Untreated urinary tract infection
    • Inability to obtain optimal access for PCNL due to obesity
    • Splenomegaly, or interposition of colon.
    • Complications of PCNL include hemorrhage (5 to 12 percent), perforation and extravasation (5.4 to 26 percent), damage to adjacent organs (1 percent), ureteral obstruction (1.7 to 4.9 percent), and infection and urosepsis (3 percent)
• Ureteroscopy
  • Gold standard for the treatment of middle and distal ureteral calculi.
  • Efficacy: 98 to 99 percent success rate for distal ureteral calculi, 51 to 97 percent for mid-ureteral calculi, and 58 to 88 percent for upper ureteral calculi.
  • Complications of URS include failure to retrieve the stone, mucosal abrasions, false passages, and ureteral perforation; complete ureteral avulsion; ureteral stricture (3 to 1 l percent); and urosepsis.
• Open surgery
  • Role has diminished to less than 1 % since era of ESWL, advanced PCNL, and ureteroscopy techniques
  • Still indicated for large complete staghorn calculi and large stone burdens in conjunction with UPJ obstruction.