II. Epidemiology
- More common in women
- Represents 15-20% of Kidney Stones
III. Pathophysiology
- Most common cause of staghorn calculi
- Cysteine Nephrolithiasis also forms staghorn stones
- Components
- Magnesium
- Ammonium
- Calcium Phosphate
IV. Risk Factors
- Neurogenic Bladder
- Urinary tract foreign body
- Urinary Tract Infection with urea-splitting Bacteria
V. Imaging
- Struvite Stones are faintly radiopaque
- Pneumaturia (gas in urinary tract) may be seen with Proteus
VI. Complications
-
Urinary Tract Infection (common)
- Intrarenal, non-obstructing staghorn stones are associated with Recurrent Urinary Tract Infections
- Non-obstructing renal staghorn stones are not a higher risk for Sepsis (until they obstruct)
VII. Management
- Start Antibiotics immediately in obstructing staghorn stone suspected of infection
- Infected obstructive stones in general are high risk for bacteremia and overwhelming Sepsis
- Urgent urology Consultation
- Surgery delayed until afebrile for 48 hours
- Consider acetohydroxamic acid (Lithostat)
- Irreversible urease inhibitor
- Prevents struvite crystallization
- Risk of Deep Vein Thrombosis
- Indications
- Calculus-related severe infections
- Patients who are not surgical candidates
- Irreversible urease inhibitor
VIII. References
- Mobley (Feb 1999) Hospital Medicine, p. 21-38
- Goldfarb (1999) Am Fam Physician 60(8): 2269-76 [PubMed]
- Houshiar (1996) Postgrad Med 100(4): 131-8 [PubMed]
- Frassetto (2011) Am Fam Physician 84(11): 1234-42 [PubMed]
- Pietrow (2006) Am fam Physician 74(1): 86-94 [PubMed]
- Preminger (2007) J Urol 178(6): 2418-34 [PubMed]
- Portis (2001) Am Fam Physician 63(7):1329-38 [PubMed]
- Segura (1997) J Urol 158:1915-21 [PubMed]
- Teichman (2004) N Engl J Med 350:684-93 [PubMed]
- Trivedi (1996) Postgrad Med, 100(6): 63-78 [PubMed]
