II. Epidemiology

  1. More common in women
  2. Represents 15-20% of Kidney Stones

III. Pathophysiology

  1. Most common cause of staghorn calculi
    1. Cysteine Nephrolithiasis also forms staghorn stones
  2. Components
    1. Magnesium
    2. Ammonium
    3. Calcium Phosphate

IV. Risk Factors

  1. Neurogenic Bladder
  2. Urinary tract foreign body
  3. Urinary Tract Infection with urea-splitting Bacteria
    1. Infection alkalinizes urine (Urine pH>7)
    2. Increases ammonium concentration
    3. Bacterial causes
      1. Proteus Mirabilis
      2. Ureaplasma Urealyticum
      3. Klebsiella Pneumoniae
      4. Pseudomonas

V. Imaging

  1. Struvite Stones are faintly radiopaque
  2. Pneumaturia (gas in urinary tract) may be seen with Proteus

VI. Complications

  1. Urinary Tract Infection (common)
    1. Intrarenal, non-obstructing staghorn stones are associated with Recurrent Urinary Tract Infections
    2. Non-obstructing renal staghorn stones are not a higher risk for Sepsis (until they obstruct)

VII. Management

  1. Start Antibiotics immediately in obstructing staghorn stone suspected of infection
    1. Infected obstructive stones in general are high risk for bacteremia and overwhelming Sepsis
  2. Urgent urology Consultation
    1. Surgery delayed until afebrile for 48 hours
  3. Consider acetohydroxamic acid (Lithostat)
    1. Irreversible urease inhibitor
      1. Prevents struvite crystallization
    2. Risk of Deep Vein Thrombosis
    3. Indications
      1. Calculus-related severe infections
      2. Patients who are not surgical candidates

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Related Studies

Ontology: Staghorn calculus (C0333014)

Concepts Disease or Syndrome (T047)
ICD10 N20.0
SnomedCT 9196004, 155868000, 266623004, 197794008
Italian Calcolo ramificato
Japanese 鹿角状結石, ロッカクジョウケッセキ
English Staghorn calculus (M-30003), nephrolithiasis with staghorn calculus (diagnosis), nephrolithiasis staghorn calculus, nephrolithiasis with staghorn calculus, staghorn calculus, Stag horn calculus, calculus staghorn, Staghorn calculus, Staghorn calculus (disorder), Staghorn calculus (morphologic abnormality), calculus; staghorn calculus, staghorn calculus; calculus
Czech Odlitková urolitiáza
Hungarian szarvasagancs kő
Dutch calculus; koraalsteen, koraalsteen; calculus, geweivormige steen
Spanish cálculo coraliforme (anomalía morfológica), cálculo coraliforme (trastorno), cálculo coraliforme, cálculo en astas de alce, Cálculo en asta de ciervo
Portuguese Cálculo ramificado
French Calcul coralliforme
German Nierenausgussstein

Ontology: Struvite calculus (C0333022)

Concepts Body Substance (T031)
SnomedCT 42851001
LNC MTHU004221
English Magnesium ammonium phosphate crystals, Magnesium ammonium phosphate calculus, Struvite calculus, Struvite calculus (morphologic abnormality)
Spanish cálculo de estruvita (anomalía morfológica), cálculo de estruvita, cálculo de fosfato amónico de magnesio

Ontology: Magnesium ammonium phosphate urolithiasis (C2919886)

Concepts Finding (T033)
SnomedCT 444690001, 282921000009103
English Magnesium ammonium phosphate urolithiasis (disorder), Magnesium ammonium phosphate urolithiasis, Struvite urolithiasis, Ammonium magnesium phosphate urolithiasis, Ammonium magnesium phosphate urolithiasis (finding)
Spanish urolitiasis de fosfato de amonio y magnesio (trastorno), urolitiasis de fosfato de amonio y magnesio, urolitiasis de estruvita