Urolithiasis update: Evaluation and management

Urolithiasis is a worldwide disease which has affected humans from ancient eras to modern times. Recently, societal changes have altered the epidemiology of urinary calculi. The incidence of urolithiasis is higher in industrialized countries. Obese people are known to have a higher risk of stone formation. Metabolic syndrome has resulted in an increasing rate of nephrolithiasis among women. There are many useful tools for diagnosing urolithiasis, including conventional plain radiography, intravenous urography, ultrasonography, computed tomography (CT), and nuclear medicine. Nonenhanced CT has high sensitivities and specificities. It can be rapidly performed without intravenous administration of contrast material and can therefore be used in patients with severely impaired renal function. Beyond that, it can reveal extraurinary causes of flank pain. However, concerns about radiation exposure and costs remain. Since ancient times, hundreds of natural plant extracts and more recently, synthetic chemicals have been proposed to eliminate urinary calculi. Clinical trials demonstrated that calcium channel blockers and adrenergic antagonists are effective in enhancing stone passage. Shock wave lithotripsy (SWL) can successfully treat renal calculi. A meta-analysis study revealed that SWL is more effective in treating urinary calculi with a lower-frequency mode. Highly dense stones are more refractory to SWL. The stone composition can be evaluated by preoperative CT attenuation values. Patients with preoperative Houndsfield units (HUs) of >750 have a 10.5-times greater chance of needing three or more sessions of SWL treatment compared to patients whose HUs are <750. Ureteroscopy is a safe treatment for managing ureter stones when performed by experienced hands and ureteroscopy is preferred over SWL in patients with a larger upper-ureter stone, those who are pregnancy, and those with bleeding diathesis.