Pathophysiology and management of infectious staghorn calculi

Staghorn calculi are large, branched stones that fill all or part of the renal pelvis and extend into the majority of the renal calices. While "stahorn" describes configuration rather than composition, most staghorn stones consist of pure magnesium ammonum phosphate (struvite) or a mixture of struvite and calcium carbonate apatite. These stones are also referred to as infection stones because of their strong association with urinary tract infection caused by urea-splitting organisms. Stories composed of uric acid or cystine may also grow in a staghorn configuration, but this only rarely occurs with calcium oxalate or phosphate stories. If left untreated, staghorn calculi may lead to deterioration of renal function, end-stage renal disease, and life-threatening urosepsis [1]. Recently, the American Urological Association (AUA) Nephrolithiasis Guidelines Panel conducted a critical meta-analysis of the existing literature to determine the optimal management for staghorn calculi. This article briefly discusses the pathophysiology of staghorn calculi and, based on the panel's recommendations, examines the alternative medical treatments (eg, chemolysis) and surgical treatments (eg, shock wave lithotripsy (SWL), open surgery, ureteroscopy, and percutaneous nephrolithotomy (PCNL)) available for staghorn patients.