Kidney Stones (Urolithiasis, Nephrolithiasis) By: E. Salehifar (PharmD, BCPS)

Background Evidence of stones in a 7000 yo Egyptian mummy Very common (2.7 million visits, >600/000 emergency situations) Men>Women More stones pass out without any intervention Treatment with various techniques

Urinary Tract

Renal Tract Stones Calcium Urate Cystine Infection (Struvite) Others

Ca 80 yes ↑ca, oxalate, ↓citrate, ↓ vol Urate 10 no ↑urate, ↓pH, ↓ Vol Stone type % of patients Visible on X-ray Risk factors in urine Ca 80 yes ↑ca, oxalate, ↓citrate, ↓ vol Urate 10 no ↑urate, ↓pH, ↓ Vol Cystine 2 weakly ↑cystine Infection (Struvite) 5 pH↑, infection Others 3

Calcium Stones Calcium Oxalate Calcium Phosphate Calcium Carbonate

Calcium Oxalate Calcium Phosphate

Calcium Carbonate

Urate Stones

Struvite

Cystine

Others

Stone Formation Causes are unclear ↑urine concentration of Ca, Oxalate, phosphate, uric acid and cystine ↓ citrate Drugs: Loop diuretics, ↑ Vit D, Indinavir food?, family history, UTI, blockage of the urinary tract, Debris or other crystals Nephrocalcinosis (mainly in medulla): Hyperparathyroidism, Distal RTA (>70%), cystic kidney disease

Ca Stones Formation Hypercalciuria (In 50% of nephrolithiasis) Idiopathic, Hyperparathyroidism, ↑Vit D, Malignancies associated with obesity & HTN ↑urine concentration of oxalate Diet, ileal disease, primary hyperoxaluria type 1 ↑urine concentration of phosphate ↓ citrate ( idiopathic, Distal RTA)

Clinical Presentation Often do not cause any symptoms Renal colic with intense flank pain often radiating to the groin, burning sensation Sometimes with nausea, vomiting, hematuria, (fever and chills in infected patients)

Diagnosis Plain Radiography (Ca, Struvite) Sonography (size & location of all stone types) <6 mm pass spontaneously, >1 cm will not CT Scan IVP (Intravenous Pyelogram)

Investigations Exclude bowel disease, diarrhea & the use of antacids and diuretics Diet assessment: Fluid, protein, Na, Ca, Oxalate, Purine & vit D Family history Stone analysis Baseline: Urine Analysis, serum Ca, P, urate, BUN, Cr Recurrent stones: 24-h urine collection Volume, Osmolality, Ca, P, Oxalate, Citrate, Urate, Na, Cr, pH as well as serum Na, K, Cl, bicarbonate

Prevention Lifestyle changes To drink more liquids Dairy product ?, Calcium pills? ↓ meat ( patients with acidic urine), ↓ vit D ↓ Oxalate (beets, chocolate, coffee, cola, nuts, rhubarb, spinach, strawberries, tea, wheat bran)

Treatments General Medical Surgical Stone removal Water (>2-3 lit/day), Pain killers Medical Surgical Stone removal Extracorporeal Shock Wave Lithotripsy (ESWL) Percutaneous Nephrolithotomy Ureteroscopic removal

Medical Therapy Hydrochlrothiazide (with low Na diet) Allopurinol Citrate potassium Thiola and Cuprimine (to ↓ cystine in the urine) UTI Prevention (after removal of struvites) Parathyroidectomy

Surgical Treatment Was necessary until 20 years ago Recovery time: 4-6 W Surgery for stone that: Does not pass after a reasonable time & causes constant pain Is too large to pass or is caught in a difficult place Blocks the flow of urine Causes ongoing UTI Damages kidney tissue or causes bleeding Has grown larger (as seen on followup X ray)

Extracorporeal Shock Wave Lithotripsy (ESWL)

Extracorporeal Shock Wave Lithotripsy (ESWL) The most frequently used procedure Most need mild anesthesia with short recovery time Complications: Hamaturia Bruising in back or abdomen (ASA should be avoided) Discomfort caused by stone passage (stent in ureter) Is not ideal for large stones

Percutaneous Nephrolithotomy (PN or PCN)

Percutaneous Nephrolithotomy (PN or PCN) For large stone or difficult location for ESWL Some type of energy probe may be needed to break the large stones Many need to nephrostomy tube Hospitalization for several days Advantage to ESWL: Stone removal by surgeon

Ureteroscopic Stone Removal

Ureteroscopic Stone Removal For mid and lower ureter stones Passage of fiberoptic ureteroscope, stone removal by cage-like device or shattering with a shock wave A small tube or stent may be inserted

Hope Through Research Why do some people continue to have painful stones? How can we predict, or screen, those at risk for getting stones? What are the long-term effects of lithotripsy? Do genes play a role in stone formation? What is the natural substance(s) found in the urine that blocks stone formation?

For More Information! www.afud.org (American Foundation for Urologic Disease) www.urologyhealth.org (American Urology Association) www.kidney.org (National Kidney Foundation)