Kidney Stones

Kim Applebee

Alex Kaullen

تعریفمقدمهشیوعانواع

تشخیصدرمان

Definition• Kidney Stones are small, hard deposits of mineral and acid salts on the

inner surfaces of the kidneys• Alternative names include:

– Renal Lithiasis– Renal Calculi– Nephrolithiasis (Kidney Stone Disease)

• Stones are classified by their location in the urinary system and their composition of crystals.

Statistics

• Incidence Rate:– More than 1 million cases annually in US– 1 in 272 or 3.6 per 1000 Americans develop

stones annually. • 80% of stones under 2mm in size• 90% of stones pass through the urinary system

spontaneously– Generally stone smaller than 6mm are

passable

 (National Institute of Diabetes and Digestive and Kidney Diseases; NIDDK)(National Kidney and Urologic Disease Information Clearinghouse; NKUDIC)

Kidney Stone Formation

• Causes:– Highly concentrated urine, urine stasis– Imbalance of pH in urine

• Acidic: Uric and Crystine Stones

• Alkaline: Calcium Stones

– Gout– Hyperparathyroidism– Inflammatory Bowel Disease– UTI – Medications

• Lasix, Topamax, Crixivan

http://www.pilotfriend.com/aeromed/medical/images2/25.jpg

Types of Stones

• Calcium Oxalate – Most common

• Calcium Phosphate • Struvite

– More common in woman than men.– Commonly a result of UTI.

• Uric Acid – Caused by high protein diet and gout.

• Cystine– Fairly uncommon; generally linked to a hereditary

disorder.

Broad classification

• Calcium containing stones– 75%

• Non calcium containing stones– 25%

Urinary tract stonesAetiology

WHEN TO INVESTIGATE ?& HOW ?

Age

Gender

Season/climate

Fluid Intake

Stress/diet

Occupation

Mobility

Metabolic disorders

Genetic disorders

Anatomical abnormality

Family history

Risk Factors for Calcium Stone-Formation

Occupation, Low Urine Volume and Urolithiasis

Occupation Percent of Male Stone-Formers

Urine Volume

(litre/day) Taxi-Drivers, Chauffeurs

5.6

1.42 0.27

Chefs, Kitchen-Workers

6.3

1.31 0.34

Urinary Risk Factors for Stone-Formation

• Low urine volume (<1L/24hrs)

• Alteration in urinary pH (<5.5,>7.5)

• Hypercalciuria (>4mg/kg/24hrs)

• Hyperoxaluria (45mg/24hrs)

• Hyperuricosuria (>600mg/24hrs)

• Hypocitraturia (<250mg/24hrs)

• Hypomagnesiuria (<50mg/24hrs)

Integrated Model of Calcium Stone-Formation

Age

Gender

Season

Climate

Fluid Intake

Stress

Affluence

Diet

Metabolic disorders

Genetic

disorders

Anatomical factors

Abnormal Crystalluria

Stone

Calcium

Oxalate

pH

Volume

Citrate

Magnesium

Uric acid

Supersaturation

Inhibitors

Promoters

Calcium Stone-Formation

Urinary tract

infection with aurea-

splittingorganism

UrinaryNH4

+

CaP and MAPsupersaturation

Abnormalcrystalluria

Infectionstone

Urinarymucoprotein

Urinarycitrate

Inhibitory activity

Nucleation and

agglomeration

UrinarypH

Urinaryphosphate

Infected Stone-Formation

AgeSex (M > F)

Genetic disorders

Metabolic disorders Dietary purine

Renal NH3 production Dietary acid

Urinaryuric acid

Uric acid supersaturation

Abnormalcrystalluria

Uric acid

stone

UrinarypH

Urinaryvolume

Fluid intake Fluid loss Ambient temperature

Uric Acid Stone-Formation

Tubularreabsorption

of cystine

Possiblemetabolic

factors

Urinarycystine

Cystinesupersaturation

Abnormalcrystalluria

Cystinestone

Cystine Stone-Formation

• It is important to discontinue any medications that interfere with the metabolism of calcium, oxalate and uric acid prior and during investigation

Diagnostic evaluation for single stone formers

• History, P/E• Medications• Fluid intake• Biochemical screen

– U&E, Ca,PO4, uric acid, bicarbonate• PTH if Ca is elevated• Urine

– PH>7.5 Infected stones– PH<5.5 Uric acid– Sediment for crystalluria– Urine culture –urea splitting organisms

• Xray• Stone analysis

Risk factors for stone recurrence

• Children• Black patients• White males with positive family history• Chronic diarrhoeal /Malabsorbtive states• Gout• Cystine/struvite/uric acid stones• Nephrocalcinosis• Osteoporosis• Pathological fractures

Extensive Investigation

• VISIT 1– History, P/E, diet, radioogical evaluation– 2X24 urinary collections for calcium, oxalate, uric acid,

citrate, urinary sodium, creatinine excretion on random diet– Dietry instructions for restricted diet

• VISIT 2– 24hr urine collection on restricted diet– Fast and calcium load test– Parathyroidlevels

Case Study

• It is a hot summer day, and you are an RN in the emergency department (ED).  S.R., an 18-year-old woman, comes to the ED with severe flank and abdominal pain and N/V. S.R. looks very tired, her skin is warm to touch, and she is perspiring. She paces about the room doubled-over and is clutching her abdomen.  S.R.  tells you that the pain started early this morning and has been pretty steady for the past  hours. She gives a history of working outside as a landscaper and takes little time for water breaks. Her past medical history (PMH) includes 3 kidney stone attacks, all during late summer. Exam findings are that her abdomen is soft and w/o tenderness, but her left flank is extremely tender to touch, palpation, and percussion. You place S.R. in one of the examination rooms and take the following VS 118/98, 90, 20, 99 F. UA shows RBC of 50 to 100 on voided specimen, WBC 0.

What key factors are important to consider?

Signs and Symptoms

• What are the key findings?– Severe flank pain – Abdominal pain– Nausea and vomiting– Fatigue– Elevated temperature, BP, and

respirations– UA positive for RBC– Objective Data: perspiration,

clutching of the abdomen, doubled-over.

– Steady Pain– Left flank tendernes

• Additional S/S:– Presence of UTI– Fever or Chills– Pain in groin, labia or testicles– Cloudy or foul-smelling urine– Dysuria– Persistent urge to void

http://knol.google.com/k/-/-/27ifsyywko3wx/sqc1f9/kidneystonesymptoms.jpg

What additional information should you ask this patient?

Additional Information

• Family history • Current medications• Frequency of urination• Do you experience pain while urinating?• What is your typical diet?• How did patient’s kidney stones resolve

themselves in the past?

http://erstories.net/wp-content/uploads/2008/10/kidneystone1a.jpg

Identify this patient’s risk factors.

Risk Factors

• What are her risk factors?– Past Medical History

• Hx of 3 kidney stone attacks

– Dehydration/Lack of Fluids

– Occupational exposure• Labor Intensive• Outdoors

– Weather/Climate• Hot, dry

• Additional risk factors:– Family or Personal Hx– Gender (male)– Age (20-55)– Race (Caucasian)– Diet

• High sodium• High protein• Food high in oxalate • Vit A/D, grapefruit juice        

– Sedentary Lifestyle– Obesity– High Blood Pressure

http://savethelobsters.files.wordpress.com/2009/02/ist2_4588664_half_empty_glass_of_water_with_clipping_path.jpg

Abnormal Lab Values

BUN

Creatinine

Urine Analysis

https://www.clevelandclinic.org/heartcenter/images/guide/tests/lab.gifhttp://www.ganfyd.org/images/f/fb/Dipstick_bottle.jpg

Diagnostic Studies

• Test and Diagnostics:– Blood Analysis– Urine Analysis– CT Scan– Abdominal x-ray– Ultrasound– Retrograde Pyelogram– Cystoscopy– Intravenous pyelography

http://knol.google.com/k/-/-/PYwIQr_i/GXb8Fg/Stone%20CT.jpg

What questions do you need to ask before a patient has an IV pyelogram?

Answer:• Do you have a history of renal failure?

– Contraindicated with renal failure

• Have you ever have a reaction to iodine? – Contrast contains iodine

• Is there a possibility you could be pregnant?• Are you currently taking any medications?

– Metformin may react with contrast– Contrast contains iodine

• Check BUN and Creatinine levels prior to IVP

Nursing Diagnosis:

Acute pain r/t obstruction from renal calculi as manifested by patient being doubled-over, pacing around the room, and patient verbalizing pain upon assessment.

Goal: patient will state pain is at a manageable level within 2 hours of admission.

What are Nursing Interventions?

Nursing Goal/Interventions:

• Administer pain medication as ordered by physician.

• Provide non-pharmaceutical techniques such as imagery and/or meditation to relieve pain.

• Patient will determine manageable pain level.

• Patient will be asked about any concerns and/or fears that may be associated with pain.

• Provide emotional support for the patient.

• Reassess patient’s pain levels within 1 hour after administration of pain medications.

Nursing Diagnoses:Deficient knowledge r/t fluid requirements and dietary restrictions as manifested by

reoccurring stones.

Goal: Patient will state methods to prevent future stones by the time patient is D/C. A plan of care will also be created with the patient before patient is D/C to prevent reoccurrence of kidney stones.

Risk for infection r/t kidney stone obstruction of urinary tract causing stasis of urine.

Goal: Patient’s urine will be yellow and clear upon D/C and patient will not have a fever. UA with show no indication of UTI or other infection.

What are Nursing Interventions?

Treatment• Two Focuses of Treatment:

– Treatment of acute problems, such as pain, n/v, etc– Identify cause and prevent kidney stones from reoccurring

• Acute Treatment:– Pain Medication!!!– Strain urine for stones– Keep Hydrated– Ambulation– Diet Restrictions– Emotional Support– Invasive Procedure (may be necessary)

http://www.free-press-release.com/members/members_pic/200906/img/1245774370.jpg

Surgical Procedures

• Lithotripsy: used to break into smaller fragments allowing it to pass through the urinary tract.

– Extracorporeal Shock-Wave (ESWL)– Percutaneous Ultrasonic– Electrohydraulic– Laser

• Surgical Therapy– Nephrolithotomy (Kidney)– Pyelolithotomy (Renal Pelvis)– Ureterolithotomy (Ureter)

• Basket Extraction

http://www.svhm.org.au/Department_Index/Lithotripsy/images/Kidney-Stones.gif

Prevention

• Patient Education– Hydration

• Drink 3 liters of fluid per day (14 cups)• Water• Lemonade (citrate decrease stone formation)

– Diet• Low sodium• Watch amounts of oxalate• Low protein

– Exercise/Increase Activity• Medication

http://3.bp.blogspot.com/_-gcaht5yp_0/SdINrCVuqdI/AAAAAAAAAGw/xeEk4-F3z_I/s320/foods+rich+in+oxalate+2.gif

Professional Resources

• Renal Disease: A Manual of Patient Care by Lynn Wenig Kagan, RN, PhD

• Differential Diagnosis: Renal and Electrolyte Disorders by Saulo Klahr, MD

• MedLine Plus

– www.nlm.nih.gov/medlineplus/kidneystones.html

Journal Article #1

• Purpose: Determine effectiveness of an herbal supplement made out of varuna and banana stems, “Herbmed,” on kidney stones

• Study: 77 patients participated in a randomized, placebo, double-blinded study that was conducted in India from July 2007 to February 2008. Two groups were formed: Group A with calculi 5-10mm and Group B with calculi >10mm.

• Results: Patients relieving the herbal supplement showed a 33% reduction in the size of their kidney stone.

• Conclusion: Herbmed is an herbal treatment that may have promising effects in reducing kidney stone size and expulsion.

Journal Article #2

• Purpose: To determine the possible effects fructose has on the formation of kidney stones.

• Study: The researchers looked at three different cohorts (older woman, younger women, and men) over combined 48 years of follow up. 4902 new symptomatic kidney stones were documented among these three cohorts.

• Results: The results from the study showed that there is a positive correlation between the intake of fructose and the development of kidney stones.

• Conclusion: Fructose intake can increase insulin resistance which lowers the pH in the urine and increases ones’ risk for the development of uric acid kidney stone. Nurses need to adequately assess the patient’s diet and educate patients on ways to prevent stones.

Journal Article #3• Purpose: The study looked specifically at anxiety associated with treatment, surgery,

for kidney stones. • Study: The anxiety of 66 patients was assessed before and after treatment, using

three forms of measurement tools: palmar sweat test, visual analogue scale, and Speilberger state anxiety questionnaire. The two groups that were compared were open surgery to minimally/non-invasive treatment.

• Results: The results from the study showed no significant change in the questionnaire answers between the three indicators of anxiety. But, there was a fair reduction in the analogue scores post-operatively in-patients who had open surgery. These same patients also had a lower palmar sweat response. But, pre-operatively patients who going to have open surgery had higher analogue scores.

• Conclusion: The two primary causes of anxiety were pain and being under anesthesia. Open surgery treatment resulted in lower levels of anxiety than non-invasive treatments.

Joey has a Kidney Stone….

• http://www.youtube.com/watch?v=BLO5beZY4zc

References• Ackley, B.J., & Ladwig, G.B. (2006). Nursing diagnosis handbook. St. Louis: Mosby, INC.. • Asselman, M., & Verkoelen, C. (2008). Fructose intake as a risk factor for kidney stone disease. Kidney International, 73(2), 139-140. Retrieved

from CINAHL with Full Text database.• Brown, S. (1990). Quantitative measurement of anxiety in patients undergoing surgery for renal calculus disease. Journal of Advanced Nursing,

15(8), 962-970. Retrieved from CINAHL with Full Text database.• Lewis, S.L., Heitkemper, M.M., Dirksen, S.R., O'Brien, P.G., & Bucher, L. (2007). Medical surgical nursing. St.Louis: Mosby, INC. . • Pagana, K.D., & Pagana, T.J. (2007). Diagnostic and laboratory test reference. St. Louis: Mosby, INC.• Patankar, S., Dobhada, S., Bhansali, M., Khaladkar, S., & Modi, J. (2008). A prospective, randomized, controlled study to evaluate the efficacy and

tolerability of Ayurvedic formulation "varuna and banana stem" in the management of urinary stones. Journal of Alternative & Complementary Medicine, 14(10), 1287-1290. Retrieved from CINAHL with Full Text database.

• (2008, June 16). Kidney Stones. Retrieved from http://www.methodisthealth.com/tmhs/basic.do?channelId=-1073830932&contentId=1073791018&contentType=HEALTHTOPIC_CONTENT_TYPE

• (2009). Kidney Stones. Retrieved from http://www.wrongdiagnosis.com/k/kidney_stones/stats.htm• (2009, June 23). Kidney Stones. Retrieved from http://www.mayoclinic.com/health/kidney-stones/DS00282 • (2009, September 30). Kidney Stones. Retrieved from http://www.nlm.nih.gov/medlineplus/kidneystones.html• (2009, October 8). Kidney Stones in Adults. Retrieved from http://kidney.niddk.nih.gov/Kudiseases/pubs/stonesadults/• (2009, October 8). Kidney and Urologic DiseasesSstatistics for the United States. Retrieved from

http://kidney.niddk.nih.gov/kudiseases/pubs/kustats/

Kidney Stones

Kim Applebee

Alex Kaullen

Definition• Kidney Stones are small, hard deposits of mineral and acid salts on the

inner surfaces of the kidneys• Alternative names include:

– Renal Lithiasis– Renal Calculi– Nephrolithiasis (Kidney Stone Disease)

• Stones are classified by their location in the urinary system and their composition of crystals.

Statistics

• Incidence Rate:– More than 1 million cases annually in US– 1 in 272 or 3.6 per 1000 Americans develop

stones annually. • 80% of stones under 2mm in size• 90% of stones pass through the urinary system

spontaneously– Generally stone smaller than 6mm are

passable

 (National Institute of Diabetes and Digestive and Kidney Diseases; NIDDK)(National Kidney and Urologic Disease Information Clearinghouse; NKUDIC)

Kidney Stone Formation• Causes:

– Highly concentrated urine– Imbalance of pH in urine

• Acidic: Uric and Crystine Stones• Alkaline: Calium Stones

– Gout– Hyperparathyroidism– Inflammatory Bowel Disease– Urine stasis – UTI – Medications

• Lasix• Topamax• Crixivan

Types of Stones• -Types of Stones (Chart pg1170)•    -Most stones contain more than one crystals. Classified by crystal that

makes up the majority of the stone.• Calcium Oxalate: Most common. Foods high is oxalate, rhubarb, star fruit,

beets, beet greens, collards, okra, refried beans, spinach, Swiss chard, sweet potatoes, sesame seeds, almonds and soy products, vitamin D, metabolic disorders, and bypass surgery increase calcium oxalate concentration in urine.

• Calcium Phosphate • Struvite stones: Most often found in women. Result of UTI. Tend to be a

stag’s-horn shape. • Uric acid stones. Formed of uric acid, a byproduct of protein metabolism.

Caused by high protein diet and gout.• Cystine stones: Fairly uncommon. Caused by kidneys over excreting amino

acid which is general linked to a hereditary disorder.

Case Study• It is a hot summer day, and you are an RN in the emergency department (ED). 

S.R., an 18-year-old woman, comes to the ED with severe flank and abdominal pain and N/V. S.R. looks very tired, her skin is warm to touch, and she is perspiring. She paces about the room doubled-over and is clutching her abdomen.  S.R.  tells you that the pain started early this morning and has been pretty steady for the past  hours. She gives a history of working outside as a landscaper and takes little time for water breaks. Her past medical history (PMH) includes 3 kidney stone attacks, all during late summer. Exam findings are that her abdomen is soft and w/o tenderness, but her left flank is extremely tender to touch, palpation, and percussion. You place S.R. in one of the examination rooms and take the following VS 118/98, 90, 20, 99 F. UA shows RBC of 50 to 100 on voided specimen, WBC 0.

What are key factors are important to consider?

Signs and Symptoms• What are the key findings?

– Severe flank pain – Abdominal pain– Nausea and vomiting– Fatigue– Elevated temperature, BP, and

respirations– UA positive for RBC– Objective Data: perspiration,

clutching of the abdomen, doubled-over.

– Steady Pain– Left flank tendernes

• Additional S/S:– Presence of UTI– Fever or Chills– Pain in groin, labia or testicles– Cloudy or foul-smelling urine– Dysuria– Persistent urge to void

What additional information should you ask this patient?

Additional Information

• Family history • Current medications• Frequency of urination• Do you experience pain while urinating?• What is your typical diet?• How did patient’s kidney stones resolve

themselves in the past?

Identify this patient’s risk factors.

Risk Factors• What are her risk factors?

– Past Medical History• Hx of 3 kidney stone

attacks– Dehydration/Lack of Fluids– Occupational exposure

• Labor Intensive• Outdoors

– Weather/Climate• Hot, dry

• Additional risk factors:– Family or Personal Hx– Gender (male)– Age (20-55)– Race (Caucasian)– Diet

• High sodium• High protein• Food high in oxalate • Vit A/D, grapefruit juice        

– Sedentary Lifestyle– Obesity– High Blood Pressure

Abnormal Lab Values

Diagnostic Studies• -Test and Diagnostics•       -Blood Analysis: Search for elevated calcium or uric acid.•       -Urine Analysis: Search for stone-forming minerals, •       -Urine Culture•       -CT Scan•       -Abdominal xray: helps monitor stone size•       -Ultrasound: may miss small stones•       -Retrograde Pyelogram•       -Cystoscopy:• -Intravenous pyelography: A contrast dye is injected into a vein in

your arm and a series of X-rays is taken as the dye moves through your kidneys, ureters and bladder. Helps determine stone location and extent of blockage. Not for pt with renal failure.

What questions do you need to ask before a patient has an IV pyelogram?

Answer:• Do you have a history of renal failure?

– Contraindicated with renal failure

• Have you ever have a reaction to iodine? – Contrast contains iodine

• Is there a possibility you could be pregnant?• Are you currently taking any medications?

– Metformin may react with contrast– Contrast contains iodine

• Check BUN and Creatinine levels prior to IVP

Nursing Dx

Outcomes/interventions?

Our outcomes and Interven.

• Invention for casestudy and general• treatment

Treatment• Two Focuses of Treatment:

– Treatment of acute problems, such as pain, n/v, etc– Identify cause and prevent kidney stones from reoccurring

• Acute Treatment:– Pain Medication!!!– Strain urine for stones– Keep Hydrated– Ambulation– Diet Restrictions– Emotional Support– Invasive Procedure (may be necessary)

Surgical Procedures

• Lithotripsy: used to eliminate the stone form the urinary tract. • Types:  extracorporeal shock-wave,

percutaneous ultrasonic, electrohydraulic, and laser.

• Nephrolithotomy (Kidney)• Pyelolithotomy (Renal Pelvis)• Ureterolithotomy (Ureter)• Basket Extraction

Prevention• Patient Education

– Hydration• Drink 3 liters of fluid per day (14 cups)• Water• Lemonade (citrate decrease stone formation)

– Diet• Low sodium• Watch amounts of oxalate• Low protein

– Exercise/Increase Activity• Medication

Professional Resources

• Renal Disease: A Manual of Patient Care by Lynn Wenig Kagan, RN, PhD

• Differential Diagnosis: Renal and Electrolyte Disorders by Saulo Klahr, MD

• MedLine Plus

– www.nlm.nih.gov/medlineplus/kidneystones.html

Journal Article #1• Purpose: Determine effectiveness of an herbal supplement made out of varuna

and banana stems, “Herbmed,” on kidney stones• Study: 77 patients participated in a randomized, placebo, double-blinded study

that was conducted in India from July 2007 to February 2008. Two groups were formed: Group A with calculi 5-10mm and Group B with calculi >10mm.

• Results: Patients relieving the herbal supplement showed a 33% reduction in the size of their kidney stone.

• Conclusion: Herbmed is an herbal treatment that may have promising effects in reducing kidney stone size and expulsion.

Journal Article #2• Purpose: To determine the possible effects fructose has on the formation of kidney

stones.• Study: The researchers looked at three different cohorts (older woman, younger

women, and men) over combined 48 years of follow up. 4902 new symptomatic kidney stones were documented among these three cohorts.

• Results: The results from the study showed that there is a positive correlation between the intake of fructose and the development of kidney stones.

• Conclusion: Fructose intake can increase insulin resistance which lowers the pH in the urine and increases ones’ risk for the development of uric acid kidney stone. Nurses need to adequately assess the patient’s diet and educate patients on ways to prevent stones.

Journal Article #3• Purpose: The study looked specifically at anxiety associated with treatment, surgery,

for kidney stones. • Study: The anxiety of 66 patients was assessed before and after treatment, using

three forms of measurement tools: palmar sweat test, visual analogue scale, and Speilberger state anxiety questionnaire. The two groups that were compared were open surgery to minimally/non-invasive treatment.

• Results: The results from the study showed no significant change in the questionnaire answers between the three indicators of anxiety. But, there was a fair reduction in the analogue scores post-operatively in-patients who had open surgery. These same patients also had a lower palmar sweat response. But, pre-operatively patients who going to have open surgery had higher analogue scores.

• Conclusion: The two primary causes of anxiety were pain and being under anesthesia. Open surgery treatment resulted in lower levels of anxiety than non-invasive treatments.

Joey has a Kidney Stone….

• http://www.youtube.com/watch?v=BLO5beZY4zc

References• Asselman, M., & Verkoelen, C. (2008). Fructose intake as a risk factor for kidney stone disease. Kidney International, 73(2), 139-140. Retrieved

from CINAHL with Full Text database.• Brown, S. (1990). Quantitative measurement of anxiety in patients undergoing surgery for renal calculus disease. Journal of Advanced Nursing,

15(8), 962-970. Retrieved from CINAHL with Full Text database.• Lewis, S.L., Heitkemper, M.M., Dirksen, S.R., O'Brien, P.G., & Bucher, L. (2007). Medical surgical nursing. St.Louis: Mosby, INC. . • Patankar, S., Dobhada, S., Bhansali, M., Khaladkar, S., & Modi, J. (2008). A prospective, randomized, controlled study to evaluate the efficacy and

tolerability of Ayurvedic formulation "varuna and banana stem" in the management of urinary stones. Journal of Alternative & Complementary Medicine, 14(10), 1287-1290. Retrieved from CINAHL with Full Text database.

• (2008, June 16). Kidney Stones. Retrieved from http://www.methodisthealth.com/tmhs/basic.do?channelId=-1073830932&contentId=1073791018&contentType=HEALTHTOPIC_CONTENT_TYPE

• (2009). Kidney Stones. Retrieved from http://www.wrongdiagnosis.com/k/kidney_stones/stats.htm• (2009, June 23). Kidney Stones. Retrieved from http://www.mayoclinic.com/health/kidney-stones/DS00282 • (2009, September 30). Kidney Stones. Retrieved from http://www.nlm.nih.gov/medlineplus/kidneystones.html• (2009, October 8). Kidney Stones in Adults. Retrieved from http://kidney.niddk.nih.gov/Kudiseases/pubs/stonesadults/• (2009, October 8). Kidney and Urologic DiseasesSstatistics for the United States. Retrieved from

http://kidney.niddk.nih.gov/kudiseases/pubs/kustats/

Medical Management of Stone Disease

Presenter: David Galvin

Moderator: Mary Dononvan

8th May 2006

Introduction

• Lifetime risk 5-15% of stone formation• Annual incidence is 0.5% in Europe• Increasing use of ESWL means stones are rarely

analysed and recurrences are higher• Increasing need for metabollic evaluation• Overlap of urine supersaturation between stone

and non-stone formers• Factors: Promoters / Inhibitors / Anatomical

1 Slide on Stone Formation

• Urine supersaturation of stone forming salts• Exceeds the Solubility Product (SP)

– Depending on pH - crystals grow and aggregrate (metastable)

• Exceeds the Formation Product (FP)– New crystals form and grow

• Crystals need to be FIXED or RETAINED for stones to form

Other Factors

• Promoters– Infection– Pyrophosphates

• Inhibitors– Citrate– Magnesium– Glycoaminoglycans

5 6 7 8 pH

Solubility

CystineUric AcidAmmoniumUrate

Phosphate

Effect of pH on Urinary Solubility of Lithogenic Substances

Stone Composition

STONE

• Struvite

• Whewellite

• Whedellite

• Dahlite

• Brushite

• Whitlockite

• Utricite

MINERAL Magnesium Amonium Phosphate Ca Oxalate Mononhydrate Ca Oxalate Dihydrate

Carbonate Apatite Ca Hydrogen PO Dihydrate Beta Tricalcium Phosphate Uric Acid

Metabollic Work Up

Who Needs Metabollic Work Up ?

• Recurrent Stone Formers

• All Children (struvite / cystine)

• Family History (cystine / xanthine / 2,8 DHA)

• At-risk for Recurrence Groups– Black women– Altered Calcium / Oxalate / Uric acid metabolism

Metabollic Disease 1

• Altered Calcium Metabolism– Hyperparathyroidism– Renal Tubular Acidosis (RTA)– Medullary Sponge Kidney (MSK)– Osteoporosis– Sarcoidosis

• Form CaOx or CaP stones

Metabollic Disease 2

• Altered Oxalate Metabolism– Primary Hyperoxaluria - Type 1 and 2– Enteric Hyperoxaluria

• Crohn’s Disease• Ulcerative Colitis• Intestinal Resection• Malabsorption syndromes

• Form CaOx stones

Metabollic Disease 3

• Altered Uric Acid Metabolism– Secondary to Cell Death

• Neoplasms, radiation, chemotherapy, anaemia

– Secondary to Enzyme defects• Gout, Lesch-Nyhan syndrome

– Altered Uric acid Excretion• Renal insufficiency, Metabollic acidosis

• Form Uric acid stones

Analysis: First Time Stone Formers

• Urine Tests– Urinalysis

• pH < 5.8 Acidic urine

5.8 - 7 constantly RTA

> 7 Infection• Erythrocytes, Leucocytes, Nitrites• Specific Gravity >1.01 Dehydration

– Microscopy and Culture– Spot Cystine (Brand’s test)

Analysis: First Time Stone Formers

• Blood Tests– Serum

• Calcium• Urate

– High (>380) Uric acid stones– Low (<120) Xanthine stones

• Creatinine

Recurrent Stone Formers: Full Metabollic Workup

• Full Medical History– GI disorders– Including Medications (diuretics, Vitamin C)– Family history

• Full Dietary History• Stone Analysis

– Chemical analysis (dated)– IR Spectroscopy or Xray Diffraction

• Bloods• Urines• CT Urogram +/- DEXA scan

Recurrent Stone Formers: Full Blood Work Up

• Calcium• Phosphate• Urate• Creatinine • Parathyroid Hormone• Optional

– ABG

Bone Profile

Renal Profile

Full Urine Analysis

• Urinalysis

• Urine Microscopy and Culture

• Spot Cystine (Brands’) Test

• 24 Hour Urine Collection– pH, Volume, Specific Gravity– Calcium, Phosphate, Uric acid, Oxalate, Creatinine, Citrate– Optional: Magnesium, Ammonium, Cystine– Diet Assesment: Urea, Na, K, Cl and Sulphate

24 Hour Urine Collection

• Acidification of 24 hour urine1. Prevents precipitation of calcium salts2. Prevents oxidation of ascorbic acid to oxalate

• Preservative (acid) solution– 5% Thymol in Isopropanol, or– 6M HCL (only if not testing for uric acid)

Additional Tests 1

• If:– 24 hour Calcium > 5mM (Hypercalciuria)– No response to medication / diet– Differentiate between Absorpitive (type 1 or 2), Renal

and Resorptive Hypercalciuria• Calcium Loading Test

– 24 hours of low calcium diet / calcium poor water– Next day: Initial urine (Blank) at 7am– Followed by Calcium load (1g) at 9 am– Second urine sample (Loading) at 12 pm

Hypercalciuria

1. Idiopathic (20%)2. Absorptive (30%)

• Excess intestinal absorption• Type 1: Not affected by calcium intake• Type 2: Only increases with increased intake

3. Renal• Reduced Calcium Reabsorption in distal tubule• Leads to PTH and secondary hyperparathyroidism

4. Resorptive• Secondary to primary hyperparathyroidism• Increased intestinal absorption and bone resorption

Additional Tests 2

• If:– Urinary pH tested on several days does not drop < 5.8– RTA results in reduced H+ secretion in distal tubule– Reduced HCO-/Cl- exchange leading to Cl reabsorption= Hyperchloraemic Metabollic Acidosis= Increased mobilistaion of calcium and Phosphate from bone– Ammonium Chloride loading test

• Taking one ammonium chloride tablet hourly between 8 am and 1 pm, five hourly urine samples are collected for pH analysis

• If pH falls < 5.4, there is no Renal Tubular Acidosis• If pH does not fall, do ABG

– If bicarbonate and pH are low = Complete RTA– If bicarbonate and pH are normal = Incomplete RTA

Renal Tubular Acidosis

• Proximal and Distal RTA• Only Distal RTA is important for stone disease• 0.5% of all stone formers have Complete Distal

RTA and are acidotic• 3-5% of all stone formers have Incomplete Distal

RTA and are not acidotic

Additional Tests 3

• If:– 24 hour urines demonstrate Hyperoxaluria– Need to differentiate between excess endogenous

production (primary) and excess absorption (enteric)

– [13C2] Oxalate Absorption test

• 2 day test involving regular urine sampling• A labelled oxalic acid dose is given at 8 am Day 2• The amount of labelled oxalate excreted in the urine is

calculated• > 10% oxalate absorption is abnormal and suggests

enteric

Evaluating the Results

pH Urinary

Calcium

Urinary

Uric acid

Urinary

Oxalate

Urinary

Citrate

Urinary

Phosphate

Serum

Urate

Serum

Calcium

Calcium

Oxalate

Low or Normal

High High High Low - - High or

Normal

Calcium

Phosphate

Low High - - Low High - High

Struvite High >7 - - - Low - - -

Uric Acid Low < 6

- High - - - - -

Xanthine - - - - - - Low -

Cystine Low <6 - - - - - - -

Interventions:General & Specific

General Measures

• Fluid Intake: 2.5 - 3 litres / day– Coffee / tea / juice / alcohol best avoided– Ideally produce 2 - 2.5 lts urine / day– Maintain specific gravity > 1.01

• Diet– Encourage fresh fruit / veg / low fat products– Avoid Animal fats and calories. Small meals.

• Lose weight. Exercise.

1. Calcium Oxalate

• 70-75% of all stones. M>F 2:1. 30-50 years• CaOx Monohydrate form in high oxalate

conditions. Very hard and dark brown.• CaOx Dihydrate form in high Ca or Mg conditions.

Yellow and softer.• Urine

– Low 24 hr citrate, volume and pH– High 24 hr calcium, oxalate and uric acid

• If Hypercalciuric Measure PTH– Look for low serum phosphate, raised ionised serum calcium

and urinary cAMP• Hypercalciuria > 8 mM/24 hrs

– Present in up to 56% of CaOx stone formers– In recurrent formers, treatment can be started at 5 mM/24 hrs

• Hyperoxaluria present in 20-50% of patients• It should be treated or recurrence rates are high

• Hypocitraturia in 50% of CaOx stone formers Needs to looked for and treated

1. Calcium Oxalate

1. Calcium Oxalate

• Hyperparathyroidism– 80% Adenoma– 15% Hyperplasia– 5% PT carcinoma

• RTA - Complete Distal– Correct acidosis with NaHCO- or K+ citrate (12-

18mM/d)

1. Calcium Oxalate

• Diet– Reduce Animal Protein Intake– Generally - no reduction in calcium intake

• But cut out hard cheese• Restrict Calcium if > 8 mM/24 hrs• Negative Ca+ balance leads to bone resorption

– Reduce Hi-Oxalate Foods (only 8% from diet)• Spinach, nuts, chocolate, tea, rhubarb, berries

– High fiber diets to bind minerals in intestine

1. Calcium Oxalate

• Medical Tx if UCa > 5mM despite diet• Aim is urinary alkalinisation:

– Potassium Citrate (9-12g/d)• Citrate binds Calcium and enhances excretion• Care in Renal failure, Hypertension, Hyperkalaemia

– Sodium Bicarbonate (4.5g/d)• Sodium can cause hypercalciuria !

– Magnesium (200-400mg/d)• Can be given if pH is normal or alkaline• Care in renal failure

1. Calcium Oxalate

• Medical Tx if UCa > 8mM despite diet

• Options:

– Thiazide Diuretics (Hydrochlorothiazide)• Increases Calcium reabsorption in distal tubules• Dose 25-50mg/d. Give with K citrate.• Care: Gout, Diabetes, Impotence (!), Hypokalaemia

– Orthophosphates

1. Calcium Oxalate

• Primary Hyperoxaluria– Pyridoxine (Vitamin B6)– Encourage normal Calcium Intake– K Citrate

• Enteric Hyperoxaluria – May be due to reduced Ca intake and less binding to Ox, High

Vitamin C intake or Idiopathic– Treat by Increasing Calcium Intake if Low, Give Oral Magnesium if

Normal. Reduce fat Intake.

2. Uric Acid Stones

• 3 - 15% of all stones. Radiolucent.• Most patients are > 60 years old• Only form in acidic urine (pH < 5.8)

– Low urine pH = Uric acid stone– High urine pH = Urate stone

• Protein / purine rich diet - Alcohol excess• 20 - 40% of gout sufferers form stones• Chemolytic treatment is 90% effective

2. Uric Acid Stones

• Findings– Serum

• Hyperuricaemia >380

– Urine• Urine pH by strip constantly < 6.0• Low volume < 2lts• Uric acid > 4mM/l (Hyperuricosuria)

2. Uric Acid Stones

• Treatment:1. Urinary Alkalinization

• Aim pH of 7 - 7.2 (Patient monitored with pH strips)• Potassium Citrate / Sodium Bicarbonate• Citrus juices / High bicarb mineral water

2. Decrease Uric acid excretion• Low purine diet• Allopurinol

• Adenine Hypoxanthine Xanthine Uric acid• Instead Xanthine oxidase converts alloprurinol to

oxypurinol

3. Increase urine dilution (3 lts / day)

3. Struvite

• 4 - 6% of all stones• Always due to urease producing bacteria: Proteus /

Pseudomonas / Klebsiella (gram -)– Splitting urea forms NH4 and HCO3 = pH

• F > M (2:1). Especially in fertile age / pregnancy• Commonest stone in children < 5 years• UTI increases ammonium and pH > 7

– This reduces phosphate solubility– Urinary Citrate and Volume are often low– Magnesium Ammonium Phosphate stones

3. Struvite

• Serum– Raised Uric acid > 380– Possibly raised Creatinine

• Urine– pH > 7– Leucocytes / Nitrites on urinalysis– 24 hour urine

• Low Volume / Alkaline Urine pH > 7• Raised 24 hr Ammonium and Phosphate

3. Struvite

• Principles– Complete Stone Removal– Eliminate urinary obstruction– Treat underlying infection

• Treatment– Long term antibiotic prophylaxis– Acidify urine: pH < 6.2

• L-methionine or Ammonium Chloride– Dilution of urine (reduce bacterial concentration)– Well balanced diet

4. Cystine

• Cystine stones are the result of an Inborn, Heritable (AR) Renal defect (1% of stones)

• Tubular reabsorption of 4 amino acids is reduced• Only Cystine is poorly soluble• Usually presents in teens (rarely childhood)• Stone constituent is always excreted in excess• Requires lifelong consistent treatment

4. Cystine

• Weakly radio-opaque• Serum is normal• Urine

– 24 hr Volume is low– Quantitative analysis: Cystine > 8 mM– Calcium / Oxalate and Uric acid may also be elevated

• Send MSU. UTI may be alkalinising urine.

4. Cystine

• Poor response to EWSL

• Often require auxillary procedures

• Stent encrustation occurs quickly

• Chemolysis rarely possible but may be obtained by alkalinisation

4. Cystine

• Treatment– Urine dilution

• Urine volume > 3.5 lts / day (1.5 lts of urine at night)– Urine Alkalinisation

• pH > 7.5. Use Alkaline citrate or Sodium Bicarb.• Measure pH regularly throughout the day.

– Medications to reduce Urinary Cystine• Ascorbic acid. • Thiola (-mercaptopropionylglycine)

– Diet• Low sodium. Low protein (avoid methionine). Drink juice.

Summary

• Modern therapies especially ESWL have made metabollic work up difficult

• Assessment is essential to reduce recurrence• First timers:

– Urinalysis, MSU, Serum Calcium and Creatinine• Recurrent Stone Formers:

– Serum and 24 hour urine analysis. Stone analysis.• Metabollic anomalies in up to 85%

STONE DISEASE

( Brief Overview )

Dr. Sunil Shroff, MS, FRCS (UK), D.Urol (Lond.),

Professor & HOD, Dept. of Urology,

Sri Ramachandra Medical College & Research Institution

Consultant Urologist & Renal Transplant Surgeon,

Sri Ramachandra Hospital, Porur, Madras.

COMPARATIVE INCIDENCES OF FORMS OF URINARY LITHIASIS

Stone analysis in Percentage

Form of Lithiasis India USA Japan UK

Pure Calcium Oxalate 86.1 33 17.4 39.4

Mixed Calcium Oxalate and 4.9 34 50.8 20.2

Phosphate

Magnesium Ammonium 2.7 15 17.4 15.4

Phosphate (Struvite )

Uric Acid 1.2 8.0 4.4 8.0

Cystine 0.4 3.0 1.0 2.8

Cause of Stone Disease

• Supersaturation of urine is the key to stone formation

• Intermittent supersaturation - Dehydration

• Crystal aggregation

• Bacterial Infection

• Defects in transport of Calcium and Oxalate by Renal

epithelia

E.Coli infection increases matrix content in urine . Proteus makes urine alkaline

Inhibitors & Promoters of Stone Formation in Urine

INHIBITORSInhibits crystal Growth -

• Citrate – complexes with Ca

• Magnesium – complexes with oxalates

• Pyrphosphate - complexes with Ca

• Zinc

Inhibits crystal Aggregation

• Glycosaminoglycans

• Nephrocalcin

• Tamm- Horsfall Protein

PROMOTERS• Bacterial Infection• Matrix • Anatomic Abnormalities – PUJ

obst., MSK • Altered Ca and oxalate transport

in renal epithelia • Prolonged immobilisation• Increased uric acid levels I.e

taking increased purine subs– promotes crystalisation of Ca and oxalate

• ?? Nanobacteria – seen in 97% of renal stones

SOME DISEASES ASSOCIATED WITH HYPERCALCAEMIA & HYPERCALCIURIA

Hyperparathyroidism Leukemia

Sarcoidosis Lymphoma

Multiple myeloma Myxedema

Hyperthyroidism Adrenal Insufficiency

Metastatic Malig. Neoplasm's Vit. D Intoxication

TYPES OF KIDNEY / URETER STONES

• OXALATE (CALCIUM OXALATE)

• PHOSPHATE

• URIC ACID & URATE

• CYSTINE

Uncommon Stones

XANTHINE STONES

– (Autosomal Recessive . Def of Xanthine Oxidase leading to Xanthinuria)

DIHYDROXYADENINE STONE

– ( Def. of enzyme adenine phospo ribosyl transferase )

SlLICATE STONES

– Rare in humans ( excess intake of Antacid with Mg Trisilicate. Mostly in cattle due to ingestion of Sand )

MATRIX

- Infection by Proteus - Radiolucent (all calculi have some amt ( 3%) of matrix but matrix calculus has 65% Matrix content in calculi)

Uncommon Stones

TRIAMTERENE

– Anti-hypertensive used with hydroclorothiazide – spare Potassium.

Mostly found as a nucleus in Ca oxalate or uric acid calculus

Indinavir Stones

- Drug to treat AIDS (4 to13%)

Ephedrine or Guifenesin

– Cough medicine - Radiolucent

Stones – Chemical Constituents

• Whewelite – Calcium Oxalate Monohydrate – CaC2O4-H2O

• Weddelite - Calcium Oxalate dihydrate – CaC2O4-2H2O

• Brushite – Calcium Hydrogen phosphate dihydrate – CaHPO4 2H2O

• Whitlockite - TriCalcium Phosphate – Ca2(PO4)2

• Struvite – Magnesium Ammonium hexahydrate – MgNH4PO4-6H2O

DD of Radiolucent filling defect on IVU in Ureter or Kidney

Must Know

• Uric Acid Calculus• Matrix Calculus• Sloughed Papilla• Blood Clots• TCC • Renal Cysts• Vascular Lesions

Know For Brownie Points

• Xanthine Calculus• Hydroxyadenine Calculus• Ephederine Calculus• Infection due to gas forming

Org.• Fungal Ball• Tuberculoma• Malacoplakia• Hypertrophied Papilla• Renal pseudo-tumour

OXALATE (CALCIUM OXALATE)

• ALSO CALLED MULBERRY STONE

• COVERED WITH SHARP PROJECTIONS

• SHARP MAKES KIDNEY BLEED (HAEMATURIA)

• VERY HARD

• RADIO - OPAQUE

Under microscope looks like Hourglass or Dumbbell shape if monohydrate and Like an Envelope if Dihydrate

PHOSPHATE STONE

• USUALLY CALCIUM PHOSPHATE

• SOMETIMES CALCIUM MAGNESIUM AMMONIUM

PHOSPHATE OR TRIPLE PHOSPHATE

• SMOOTH MINIMUM SYMPTOMS

• DIRTY WHITE

• RADIO - OPAQUE

Calcium Phosphate also called ‘Brushite’ appears like Needle shape under microscope

PHOSPHATE STONES

IN ALKALINE URINE

ENLARGES RAPIDLY

TAKE SHAPE OF CALYCES

STAGHORN

Struvite can form Stag-horn and appear like coffin lid under microscope

CALCIUM PHOSPHATE STONES

• Hyperparathyroidism Ca P

• Renal Tubular Acidosis K CO2

• Medullary Sponge Kidney -

PTH Hormone Promotes renal production of 1-25-dihyroxycholecalciferol – active Vit.D and also

increases absorption of Calcium and decreases Phosphorus absorption from Kidneys

URIC ACID & URATE STONE

• HARD & SMOOTH

• MULTIPLE

• YELLOW OR RED-BROWN

• RADIO - LUCENT (USE ULTRASOUND)

Under microscope appear like irregular plates or rosettes

pKa of uric acid 5.75 – at this pH 50% of uric acid insoluble.If pH falls further - uric acid more insoluble

CYSTINE STONE• AUTOSOMAL RECESIVE DISORDER

• USUALLY IN YOUNG GIRLS

• DUE TO CYSTINURIA -

• CYSTINE NOT ABSORBED BY TUBULES

• MULTIPLE

• SOFT OR HARD – can form stag-horns

• PINK OR YELLOW

• RADIO-OPAQUE

Under microscope appears like hexagonal or benezene ring – ask for first morning sample

CYSTINE STONE - Management

• High Fluid Intake and Alkalanise Urine – dissolve most of

the smaller cystine stones

• D-Pencillamine or MPG (Mercaptopropionylglycine) binds

to cystine that is soluble in urine

• Side effects of Pencillamine restricts it use – Allergic

rashes, GI problems- Nausea, Vomiting, Diarrhoea

• MPG better tolerated

• Large obstructive stones – Surgery required first

Cyanide Nitroprusside Calorimeteric Test for detecting Cystinuria. If positive do amino acid chromatography

pKa of cystine is 8.3, hence alkalinisisation above pH7.5 helps to dissolve the stones

Surgical Conditions and Stone Disease

• Regional ileitis and Ileal Bypass Surgery for eg Obesity can lead to increase oxalate absorption and stone ds

• ileostomies - In Chr. Diarrhoea with– Bicabonate loss – systemic acidosis and acidic urine – increases risk of Uric Acid stones

HISTORY

A. IS PATIENT DRINKING ENOUGH ?

B. PROFESSION

C. ENQUIRE ABOUT UTI STONES

D. FAMILY HISTORY

E. LONG ILLNESS BEDRIDDEN STONES

MANAGEMENT OF STONES

HISTORY :

A. FIND OUT IF DRINKING ENOUGH LIQUIDS

(NOT DRINKING ENOUGH IMPORTANT CAUSE

OF STONE FORMATION & GROWTH)

Urinary supersaturation of salts in concentrated urineAtleast drink 3 lits to avoid stone formation

HISTORY (Cont...)

B. ASK ABOUT THEIR PROFESSION

DEHYDRATION STONES CAN FORM e.g.

• MARATHON NEAR A FURNACE,

• BRICK - LAYER, LABOURERS & WEAVERS

• TRUCK & BUS DRIVERS

C. ENQUIRE ABOUT UTI STONES

D. FAMILY HISTORY

E. LONG ILLNESS BEDRIDDEN STONES

HISTORY (Cont...)

Zero Gravity state – astronauts on long space flights more prone to stones

CLINICAL FEATURES

1. PAIN IN 75 % OF THE CASES

“RENAL COLIC” IF SEVERE AND ACUTE

A) KIDNEY STONE

FIXED PAIN IN THE LOIN

B) URETERIC STONE

PAIN RADIATES LOIN TO GROIN

Both Stomach & Kidney supplied by celiac ganglion hence Nausea & vomiting common in renal colic

CLINICAL FEATURES (Contd....)

2) HAEMATURIA

• CAN BE FRANK

• OR ONLY FOUND ON DIP - STICK OR LAB.

3) PYURIA - IF INFECTION CAN HAVE PUS IN URINE

ON EXAMINATION

1. ACUTE PRESENTATION

• ABDOMEN TENSE AND RIGID

• TENDERNESS PRESENT IN THE LOIN

2. IN ROUTINE PRESENTATION

• NO FINDINGS IN ABDOMEN

INVESTIGATIONS

1. FULL BLOOD COUNT TO CHECK FOR

ANAEMIA IF GOING FOR SURGERY

2. SERUM ELECTROLYTES PLUS UREA /

CREATININE / CALCIUM / URIC ACID /

PHOSPHATE

INVESTIGATIONS (Cont...)

3. 24-HOURS URINE FOR ELECTROLYTES

(Only if recurrent stone former)

CALCIUM / OXALATE / URIC ACID /

CYSTINE / CITRATE

INVESTIGATIONS (Cont...)

4. PLAIN KUB X-RAY OF ABDOMEN (Mandatory)

5. IVU OR IVP (INTRA VENOUS UROGRAM)

6. ULTRASOUND (Mandatory)

INVESTIGATIONS

IVU OR IVP (INTRA VENOUS UROGRAM)• Not Mandatory• 1in 40,000 patients die due to anaphylactic reaction to

contrast• Useful for radio-lucent stones & to detect

Congenital Anomalies in Urinary tracts

INVESTIGATIONS (Cont...)

7. CT –

TO LOOK AT UNUSUAL ANATOMY OF THE KIDNEY

To differentiate cause of acute colic – stone or anuria

Suspected due to stone disease

8. DMSA OR DTPA OR MAG3 RENOGRAM - TO STUDY FUNCTION OF

EACH KIDNEY.

Bilateral Ureteric Calculus in a patient presenting with Anuria Bilateral Ureteric Calculus in a patient presenting with Anuria

Helical or Spiral CT provides 3D reconstruction. Helical refers to path the X ray follows on Gantry. These are rapidly performed and do not require contrast agents for reconstruction.

MANAGEMENT OF UROLITHIASIS

• Non-invasive approach to urinary calculas-HALLMARK of last 20 yrs.

• Lithotripters –

1.Extra Corporeal Shock wave

2.Intra Corporeal

• Better fiber optics – Miniturisation of Telescopes • Accessories - Innovative variety

Modern Management of Urolithiasis

• ESWL• Ureterorenoscopy• Percutaneous Nephrolithotomy• Laparoscopic Approach to stones

Open Ureterolithotomy, Pyelolithotomy or Nephropyelolithotomy is required in less than 1 to 2% of modern stone management

TREATMENT (IDEALLY)

MAJORITY : 80 TO 85 % of all stones can be treated by -

EXTRA - CORPOREAL SHOCK WAVE LITHOTRIPSY (ESWL)

MINORITY : 15 TO 20 % SHOULD NEED MINIMALLY

INVASIVE SURGERY (PCNL / URETEROSCOPY)

(LESS THAN 1 % SHOULD NEED OPEN SURGERY)

EXTRA - CORPOREAL SHOCK WAVE LITHOTRIPSY(ESWL)

SHOCK WAVES GENERATED UNDER WATER CAN

TRAVEL THROUGH BODY WITHOUT ANY APPRECIABLE

LOSS OF ENERGY. WHEN THEY ENCOUNTER STONES

THE CHANGES IN DENSITY CAUSES ENERGY TO BE

ABSORBED AND REFLECTED BY THE STONE & THIS

RESULTS IN FRAGMENTATION OF THE STONES.

ESWL – For Urinary Tract CalculusESWL – For Urinary Tract Calculus

ESWL- FOUR MAIN ELEMENTS

1. ENERGY SOURCE

2. FOCUSING DEVICE

3. COUPLING DEVICE

4. LOCALIZATION DEVICE

ESWL

Absolute Contra-indication-Pregnancy

Relative Contra-Indications for ESWL –

• Renal Colic• Urinary obstruction • Infection• Declining Renal Function• Significant Hematuria

COUPLING DEVICE

“WATER BATH”

“WATER FILLED CUSHION”

(KEEP PATIENT’S DRY)

ESWL-HISTORY

1963-EXPERIMENTS WITH “ SHORT WAVES” IN W.GERMANY BY PHYSICISTS AT DONIER SYSTEMS LTD

1980-DORNIER HUMAN MODEL ( HM-3)

LITHOTRIPTER ARRIVED ON MARKET

(STILL GOLD STANDARD WHEN COMPARING RESULTS WITH NEW MEASUREMENTS

ESWL & STAGHORNS

• Dornier HM-3 Monotherapy for STAGSHORNS -

30% Stone Free Rate (In Dilated Collecting System )• PCNL has higher overall Success• Combination of PCNL & ESWL can give a

stone free rates of 90% For ALL STONES IN THE KIDNEY

COMPRESSION-TENSILE WAVE CAUSES:

“Implosion” Rather than “Explosion”

ESWL & URETERIC CALCULI

• For fragmentation fluid medium around stone necessary

• If stones impacted fragmentation may not occur

• “PUSH & BANG”-success Marginally HIGHER THAN “in situ ESWL”

• Trial of “in situ ESWL” – first choice • “In situ ESWL” FAILS- “Rescue procedure”

ESWL COMPLICATIONS

• Haematuria – is quite common ( short term antibiotics Recommended )

• Incomplete stone Fragmentation & Obstruction• “Stienstrasse” ( stone street ) usually due to a

large “ Leading fragment”

( Stents Recommended prior to ESWL for Calculi > 1.5 cm )

DESIGN BASIC LITHOTRIPSY

Renal Lithiasis Blood Pressure Study ( Patients treated 1984-1986

Dallus Study)

First Follow Up Second Follow Up

1988 1990

No.Pts Annualized Rate No.Pts Annualized Rate of Hypertension of Hypertension

ESWL 771 2.5% 590 2.1%

non-ESWL 195 3.8% 155 1.6%

Total 966 745

Basic Principles of

“SHOCK WAVE”

Lithotripsy

FRAGMENTATION BY SHOCK WAVES

ON COLLISION OF “ SHOCK WAVES” WITH CALCULI-

• ON FRONT SURFACE – COMPRESIVE FORCES• ON BACK SURFACE OF THE STONE-

REFLECTION OF COMPRESSION PULSE CREATES NEGATIVE OR TENSILE WAVE THAT TRAVEL BACK WARD THROUGH CALCULI

• ONCE TENSILE FORCE EXCEEDS “ COHESIVE STRENGTH” OF CALCULI- FRAGMENTATION OCCURS

ESWL – SPARK GAP/ EHL

• Electro-hydraulic Generator Located at Base of Water Bath

• Produces Shock wave by Electric Spark Gap of 15,000 to 25,000 Volts Lasting 1 Sec

• High Voltage Spark Discharge Rapidly-

evaporates Water & Generators A “Shock Wave” by expanding Sarrounding Liquid

Mechanism of Stone Fragmentation by ESWL

• On Front Surface – Compresive or positive Forces• On Back Surface Of The Stone-

Reflection Of Compression Pulse Creates Negative Or Tensile Wave That Travel Back Ward Through Calculi

• Once Tensile Force Exceeds “ Cohesive Strength” Of Calculi- Fragmentation Occurs

• Cavitation – Small air bubbles

Steinstrasse ( or Stone Street) – Post ESWL

Diet & Fluid Advice

• High Fluid Intake

• Restrict Salt (Na)

• Oxalate Restrict

• Avoid high intake of Purine food

• Increased citrus fruits may help

• If hypercalciuria restrict Ca intake

Role of Potassium Citrate in preventing Cal Oxalate stone ds – KCit lowers

urinary calcium whereas Na Citrate does not lower Calcium due to Sodium load

LIQUIDS

Moderate Amounts : High Amounts :

Apple Juice Cocoa

Beer Fresh Tea

Coffee

Cola

FOODS :

Almonds, Asparagus, Cashew Nuts, Currants, Greens,

Plums, Raspberries, Spinach

HIPPOCRATIC OATH :

“I Will not cut, even for the stone, but leave such

procedures for the practitioners of the craft”

Urinary Calculi

Dave Pettersson MS4Diagnostic RadiologyAugust 2007

The Problem

Many people get them…12% lifetime incidence of urolithiasis. (Sierakowski)

Expenditure on urinary stones is rising…

$2 billion in 2000. (Pearle)

The Problem

• Care for urolithiasis is shifting from the inpatient to outpatient setting.

• Minimally invasive treatments are replacing others.

So why the rise in cost?

Does inappropriate imaging have something to do with it?

(Pearle)

Goals

• Basics of urinary tract stone disease• Selecting the appropriate imaging option • Findings on imaging

Epidemiology

Who gets them?-12% lifetime incidence-Men affected 3 times as often as women-Incidence rises until age 60

After first episode, stones tend to recurAfter first episode, stones tend to recur……

At 1 year 15% of patients will get another stone At 1 year 15% of patients will get another stone

At 5 years… 35%At 5 years… 35%

At 10 years… At 10 years… 50%50% (Uribarri)(Uribarri)

Five Common Stone Types

Calcium Oxalate/

Calcium Phospahte

75 Underlying Metabolic disorder… (e.g., idiopathic hypercalcuria, hyperoxaluria)

No metabolic disorder identified in 25%

Struvite 10–15 Renal Infection…

(Proteus, Klebsiella)

Uric Acid 6 50% idiopathic;Hyperuricemia, hyperuricosuria

Cystine 1-2 Renal tubular defect

Percent of all stones Etiologic Factors

(Sandhua)

Why stones form…Urine becomes supersaturated…

1. Decreased urine volume

2. Abnormal urine pH

3. Absence of inhibitors

4. Infection

A Portland Native!

Why stones form…

1. Decreased urine volume… Urine concentrates, supersaturates & crystals precipitate.

2. Urine pH affects solubility…

Acidic urine: Uric acid, Cystine, Ca Oxalate

Alkaline urine: Ca phosphate, struvite

Promotes precipitation of:

Why stones form…

3. Absence of inhibitors

Citrate, glycosaminoglycans and Tam Horsfall proteins tend to inhibit stone formation

4. Infection:

Urea-splitting organisms (Proteus, Klebsiella) generate ammonia and alkalinize urine

Proteus Urease Staghorn calculi (struvite)

Who gets stones…

• Those with metabolic disorders that affect the concentration of urine solutes …

SecondarySecondary:: Hypercalciuria: primary hyperPTH, type 1 RTA, sarcoidHypercalciuria: primary hyperPTH, type 1 RTA, sarcoidHyperoxaliuria: Crohn’s or other ileal disease with intact colonHyperoxaliuria: Crohn’s or other ileal disease with intact colonHyperuricosuria: gout, myelo- and lymphoprolipherative disordersHyperuricosuria: gout, myelo- and lymphoprolipherative disorders

IdiopathicIdiopathic: : hypercalciuriahypercalciuriahyperoxaliuriahyperoxaliuriahyperuricosuriahyperuricosuriahypocitraturiahypocitraturia

Who gets stones…

Those with structural kidney disease

Medullary Sponge Kidney

(Learningradioplogy.com)(Emedicine.com) Horseshoe Kidney

Polycystic Kidney Disease

Who gets stones…

Zero gravity promotes bone demineralization causing elevated calcium levels in urine.

Who gets stones…

Often, no underlying cause is found.

How they form…

Two hypotheses…

1. Stones form in the renal medulla and are extruded by the collecting ducts

2. Stones form on papilla

A. Calcium oxalate stone at tip of renal papilla.

B. Plaque and medullary collectingducts exposed following stone removal.

(Urologic Clinics of North America)(Urologic Clinics of North America)

The fate of a stone…

(Teichman)

Depends on size and location of stone

Complications…A stone can lodge in the ureter, obstruct urine flow and dilate the proximal

collecting system.

Elevated hydrostatic pressure in the collecting system can have detrimental effects on kidney function…

infectionpyelonephritisperinephric abscessurosepsis

hydroureterhydronephrosisurine extravasationrenal failure

Presentation…

+

(Rolling Stones)

Presentation…

Renal colicRenal colic: : -acute onset of sharp, spasmodic flank pain-acute onset of sharp, spasmodic flank pain-episodes of severe pain last 20 – 60 minutes-episodes of severe pain last 20 – 60 minutes-location of pain depends on location of stone-location of pain depends on location of stone

Mechanism for painMechanism for pain::-stone lodges in ureter -stone lodges in ureter -ureteral spasm and hyperperistalsis -ureteral spasm and hyperperistalsis

ensueensue-distention of renal capsule causes pain-distention of renal capsule causes pain

Stones are found most commonly at…Stones are found most commonly at…1.1. The ureteropelvic junctionThe ureteropelvic junction2.2. The iliac vesselsThe iliac vessels3.3. The ureterovesical junctionThe ureterovesical junction

Presentation…

Hematuria (microscopic or gross):

-90% of patients have hematuria on first day of pain

-only 65% will have hematuria on days 3 and 4

(Kobayashi)(Kobayashi)

-Sometimes nausea and vomiting (if celiac ganglion irritated)-Sometimes nausea and vomiting (if celiac ganglion irritated)-May also see signs and symptoms secondary to complications-May also see signs and symptoms secondary to complications

Presentation…

Staghorn Coral Staghorn FernStaghorn Calculus

Staghorn caluliStaghorn caluli are are typically asymptomatictypically asymptomatic(unless there is obstruction or infection)(unless there is obstruction or infection)

Diagnosis…

However, fewpatients fit neatly into algorithms.

(Portis)

The standard work-up for suspected renal colic begins with imaging...

Diagnosis…

For patients with flank pain and a suspected first

episode of urolithiasis…

Non-Contrast Helical CT is recommended.

For patients with flank pain and For patients with flank pain and history of stoneshistory of stones……Plain Film RadiographPlain Film Radiograph is appropriate is appropriate

(ACR Appropriateness Criteria)

How is imaging helpful?

1. Establish cause of pain & hematuria

2. Rule-out other potential causes of pain

3. Stone size, location and density dictate treatment plan and expected course…

Stone <5 mm will likely pass Stone <5 mm will likely pass

Stones >10 mm very unlikely to pass spontaneouslyStones >10 mm very unlikely to pass spontaneously

Diagnosis…

After a patient’s first stone, should she/he be worked-up to find an underlying cause?

Or should this evaluation be saved for the second bout of renal colic?

There is no consensus!There is no consensus!

Diagnosis…

If a patient’s history, physical exam and labs are suggestive of uncomplicated urolithiasis, is a CT necessary?

…many sources say yes. (Portis, Teichman,)

But will CT results change management?

Diagnosis…The American College of Radiology recommends either IVP or non-contrast CT for

evaluation of suspected first-time urolithiasis.

(www.acr.org)

Diagnosis…

A work-up to find the underlying cause for stone formation might include…

24 hour urine24 hour urineCaCaPO4PO4uric aciduric acidOxalateOxalateCitrateCitrateNaNaCrCrpHpH

Blood testBlood test BMPBMPPO4PO4PTHPTHuric aciduric acid

Spot urineSpot urineUAUAurine sedimenturine sedimenturine cultureurine culturestone fragment analysisstone fragment analysis

Non-Contrast Helical CT

The preferred study for work-up of suspected urinary tract calculi.

1. Fast 2. No contrast3. Characterize size & location of stone… (and guide management ?)4. Characterize degree of urinary tract obstruction5. Higher sensitivity (96%) and specificity (98%) for ureterolithiasis than any other

study (ACR)

6. Able to evaluate for other sources of pain. 7. Cost of CT is comparable to IVP (Pfister)

8. Virtually all stones are radiopaque

Normal Urinary Anatomy (CT Urography)

Normal Normal renal pelves enhanced renal pelves enhanced with contrast (arrows)with contrast (arrows)

Opacified upper ureters (arrows)Opacified upper ureters (arrows)

(McTavish)(McTavish)

Opacified lower ureters (arrows)Opacified lower ureters (arrows)Opacified distal ureters (arrows)Opacified distal ureters (arrows)

(McTavish)(McTavish)

Normal Urinary Anatomy (CT Urography)

Find the stone…Most commonly, the stone can be seen directly as an

opacity within the urinary tract.

Impacted calculus atImpacted calculus atureterovesical junctionureterovesical junction

Stone in left ureterStone in left ureter(Catalano)

CT Findings…

Staghorn calculus in right renal pelvisStaghorn calculus in right renal pelvis

(Curhan)(Curhan)

CT Findings…

Sometimes the ureteral mucosa is damaged

by the adjacent stone and becomes inflamed,

edematous, and thickened.

This can be seen on CT as a soft tissueThis can be seen on CT as a soft tissuerim surrounding the opaque stone…rim surrounding the opaque stone…

Soft-tissue rim signSoft-tissue rim sign

(Rochester)

Soft-tissue rim sign…

Ureteral stone Ureteral stone ((arrowheadsarrowheads) in right pelvis ) in right pelvis with periureteral stranding with periureteral stranding and soft-tissue rim signand soft-tissue rim sign

(Catalano)(Catalano)

Sharp crystals of calcium oxalate Sharp crystals of calcium oxalate can damage adjacent ureteral mucosacan damage adjacent ureteral mucosa

(SEM micrograph)(SEM micrograph)

CT Findings…

If a stone can’t be seen directly, then secondary signs of urolithiasis can help make the diagnosis…

1. Perinephric fat stranding (secondary to edema)

2. Hydronephrosis (dilation of kidney)

3. Hydroureter: (dilation of ureters)

Secondary Signs on CT…

Perinephric Stranding

(Varanelli) (Catalano)(Catalano)

Secondary Signs on CT… Hydroureter Hydronephrosis

(Catalano)(Catalano)

Dilated renal pelvis (arrowhead) with minimal Dilated renal pelvis (arrowhead) with minimal surrounding fat-tissue strandingsurrounding fat-tissue stranding

(McDonald)(McDonald)

Hydronephrosis in right kidney (long arrow)Hydronephrosis in right kidney (long arrow)and tiny right renal calculus (short arrow).and tiny right renal calculus (short arrow).Left kidney is normal. Left kidney is normal.

Utility of Secondary Signs

CT Images of Stones

1. The stone recently passed (dilation and stranding persist after passage).

2. Indinavir stones (protease inhibitor for HIV) are one of the few stones not seen on CT (rare)

3. The CT section thickness is too wide (discussed in a few slides)

4. There is another cause for ureteral obstruction (look for alternate diagnosis)

There is ureteral dilation and perinephricThere is ureteral dilation and perinephric stranding, but I can’t see a stone. Why? stranding, but I can’t see a stone. Why?

Beware of Phleboliths…

Calcified remnants of thrombi in veins.

Easily mistaken for urinary calculi on CT…

Calcifications are consistent with ureteral stone (red arrowhead) Calcifications are consistent with ureteral stone (red arrowhead) and phleboliths (yellow arrowheads). and phleboliths (yellow arrowheads). (Urologystone.com)(Urologystone.com)

Phleboliths-Often appear opaque on CT -Have central lucency on plain film

If uncertain about plebolith vs. urolith…If uncertain about plebolith vs. urolith…

1.1. Try to determine location. If in ureter, Try to determine location. If in ureter, then calcification is a urolith then calcification is a urolith

2.2. If soft tissue rim is present, then likely a If soft tissue rim is present, then likely a urolithurolith

3.3. If tail sign present, then opacity is likely a If tail sign present, then opacity is likely a phlebolith (see right)phlebolith (see right)

4.4. If uncertainty persists, then a follow-up If uncertainty persists, then a follow-up CT with contrast will opacify ureterCT with contrast will opacify ureter

Tail sign: tail of soft-tissue attenuation Tail sign: tail of soft-tissue attenuation ((arrowarrow) ) extending anterior to phlebolithextending anterior to phlebolith (Boridy)

CT Section Width

A stone can be missed if the section width is too great, due to the effect of partial volume averaging.

CT images of same patient, at same level. The stone could easily be missed when the CT images of same patient, at same level. The stone could easily be missed when the CT section width is 5.0 mm. This stone measured 3.0 mm. CT section width is 5.0 mm. This stone measured 3.0 mm.

1.5 mm1.5 mm3.0 mm5.0 mm

(Memarsadeghi)

Intravenous Urograpgy/Pyelography(IVU/IVP)

Intravenous contrast is filtered by the kidney and concentrated in the urine…

Sequential radiographs are obtained to see how contrast moves through the urinary tract…

This highlights urinary tract anatomy and provides information about renal function

IVU (IVP)

Advantages

Allow assessment of renal Allow assessment of renal functionfunctionShows location and degree of obstructionShows location and degree of obstruction

Assess size of stone (sometimes)Assess size of stone (sometimes)

DisadvantagesRequires contrastRequires contrastCan take a while to completeCan take a while to completeFail to identify alternate diagnosesFail to identify alternate diagnoses

Until the mid 1990’s, IVU was study of choice for evaluation of suspected Until the mid 1990’s, IVU was study of choice for evaluation of suspected urolithiasis. urolithiasis.

Currently, it is the study of choice when CT is not available. Currently, it is the study of choice when CT is not available. (ACP)(ACP)

IVP study showing normal urinary anatomy

IVP

An abnormal IVU study showing obstructed, dilated left ureter and collecting system (Sudha)

Urogram shows dilatation of left ureter Urogram shows dilatation of left ureter and collecting system caused by calcific and collecting system caused by calcific distal ureteral stone (distal ureteral stone (arrowarrow). (Sudha)). (Sudha)

CT vs IVP

IVP was the standard for imaging of suspected urolithiasis until the mid 1990’s.

IVP was replaced by Non-Contrast Helical CT as imaging study of choice for evaluation of suspected urolithiasis.

Why is CT preferred over IVP?1. CT is faster2. CT is safer as it does not require contrast 3. Overall, CT is more cost effect than IVP

(Initial CT is more expensive than initial IVP, but with IVP there is the need for more follow-up imaging) (Pfister)

4. CT is more reliable in diagnosing nephrothiliasis5. CT is more reliable in diagnosing alternate causes of flank pain6. CT and IVP have same reliability at diagnosing obstruction

(ACR, Smith)

However, CT generates twice the radiation exposure of IVP(6.5 mSv vs. 3.3 mSv) (Pfister, Thompson)

KUB…A plain film radiograph of the

Kidneys, Ureters, and Bladder

Stone in right kidney

First choice of imaging in diagnosis of First choice of imaging in diagnosis of suspected suspected urolithiasis in patinets with a history of stone urolithiasis in patinets with a history of stone disease disease and previous KUBs and previous KUBs (ACR)(ACR)

Patients with a history of stones don’t Patients with a history of stones don’t need a CT for each episode of renal colic.need a CT for each episode of renal colic.

Plain Film Radiography…For evaluating initial episodes of suspected urolithiasis, the KUB’s sensitivity for

detecting stones is low (58%- 62%) (ACR)

KUB will missKUB will miss: : uric acid stones uric acid stones small stones small stones stones obscured by bonesstones obscured by bones

KUB will detectKUB will detect: : calcium stones calcium stones struvite struvite cystine stonescystine stones

Radiograph of left kidney showsRadiograph of left kidney shows a large stone (arrow) a large stone (arrow) (Susah).(Susah).

Radiographs…

View of pelvis shows radiopaque View of pelvis shows radiopaque calculus. calculus. (Zagoria)(Zagoria)

Small calcification (Small calcification (arrowarrow), suspected ), suspected for ureteral stone. for ureteral stone. (Catalano)(Catalano)

Ultrasonography (US)…First choice for diagnosis of urolithiasis in…

1. pregnant patients 2. children

Sonographic scan shows Sonographic scan shows dilated intrarenal dilated intrarenal collecting system, collecting system, consistent with consistent with obstructive urolithiasis.obstructive urolithiasis.

(Catalano)

US…

Advantages

1. Safe, non-invasive…

ideal for pregnant patients & children

2. Sensitive for detecting urinary tract dilation

Nephrolithiasis (arrows) Nephrolithiasis (arrows) without hydronephrosiswithout hydronephrosis

(Sheafor)(Sheafor)

US…

Disadvantages1. Urinary tract dilation can take hours to develop,

so the diagnosis of obstructive uropathy may be missed at the initial evaluation.

2. May miss small stones and stones in ureters3. Patients need to be hydrated before exam4. Stone size cannot be accurately measured

ureteral stone (ureteral stone (arrowarrow) ) hydroureterhydroureter ( (arrowheadsarrowheads))

(Catalano)(Catalano)

Color Doppler Sonogram…

Scan of ureterovesical jets shows Scan of ureterovesical jets shows normal normal right color jet (R) and absent left jet right color jet (R) and absent left jet (L) consistent with obstruction of the (L) consistent with obstruction of the left ureter. left ureter.

A ureteral calculus can obstruct urine flow and prevent the normal peristaltic expulsion of urine into the bladder, i.e. the “jet”.

(Catalano)(Catalano)

CT Urography…

Used primarily for further work-up of abnormalities seen on initial unenhanced CT

3-D coronal reconstruction of CT urography image, showing contrast-enhanced renal collecting system, ureters, and bladder. Note duplicated system on left side.

(www.massgeneralimaging.org)

Axial CT urography image showing a filling defect in the right renal pelvis consistent with a large urothelial tumor.

Magnetic Resonance Urography (MRU)

Limited role in evaluation of urinary tract stones.

(Sudah)(Sudah)Dilatation of left ureter and collecting system (both images)

MRU

The ureteral stone is seen The ureteral stone is seen as a filling defect (arrow)as a filling defect (arrow)

MR urography can replace conventional excretory urography (IVU) when the latter is contraindicated or undesirable. (Sudah)

Treatment…

• Stones <5mm are likely to pass spontaneously

• Stones >10mm are very unlikely to pass spontaneously

• Also, distal stones are more likely to pass spontaneously

When to hospitalizeWhen to hospitalize??1.1. ObstructionObstruction2.2. InfectionInfection3.3. Intractable painIntractable pain4.4. Not taking PONot taking PO

HydrationHydration

(IV or PO) (IV or PO) AnalgesiaAnalgesia (NSAIDS & Opiods)(NSAIDS & Opiods)

&

Treatment…

Another algorithm… (for what it’s worth).

(Curhan)(Curhan)

ESWL = extracorporeal shockwave lithotripsy

Treatment…

If an underlying cause has been identified in a recurrent stone former, then long-term treatments may be considered…

Most patients will likely benefit Most patients will likely benefit from from increased fluid intake (> 2 L/day)increased fluid intake (> 2 L/day)

Calcium stonesCalcium stones::1. thiazide diuretic 1. thiazide diuretic 2. low sodium diet for hypercalciuria 2. low sodium diet for hypercalciuria 3. DO NOT decrease Ca intake 3. DO NOT decrease Ca intake

(causes hyperoxaliuria and osteoporosis)(causes hyperoxaliuria and osteoporosis)

Treatment…

Hypocitraturia:

potassium citrate replacement

Cystine stonesCystine stones:: 1. high fluid intake1. high fluid intake2. urinary alkalinization (potassium citrate)2. urinary alkalinization (potassium citrate)

Uric acid stonesUric acid stones: :

1. urine alkalinization (potassium citrate); 1. urine alkalinization (potassium citrate);

2. allopurinol2. allopurinol

Struvite stonesStruvite stones (Magnesium ammonium phospahate): (Magnesium ammonium phospahate):1.1. typically require stone removal with percutaneous typically require stone removal with percutaneous nephrolithotomy nephrolithotomy 2. antibiotics to treat urease-producing bacteria2. antibiotics to treat urease-producing bacteria

ReviewNon-contrast helical CT is the study of choice for evaluation of a

first episode of suspected urolithiasis.

However, for suspected urolithiasis in a known stone former… consider a plain film radiograph first….

It may lower healthcare costs!

References

ACR. American College of Radiology Appropriateness criteria: Acute onset flank pain. www.acr.org 2005Boridy IC, et al. Ureterolithiasis: value of the tail sign in differentiating phleboliths from ureteral calculi at nonenhanced helical CT. Radiology. 1999

Jun;211(3):619-21.Catalano O, et al. Suspected Ureteral Colic: Primary Helical CT Versus Selective Helical CT After Unenhanced Radiography and Sonography AJR 2002;

178:379-387.Chen MY, et al. Can noncontrast helical computed tomography replace intravenous urography for evaluation of patients with acute urinary tract colic?

J Emerg Med 1999 Mar-Apr;17(2):299-303.Curhan GC, et al. Diagnosis and acute management of suspected nephrolithiasis. UTDOL.com Accessed August 24, 2007.Kobayashi T, et al. Impact of date of onset on the absence of hematuria in patients with acute renal colic. J Urol 2003 Oct;170(4 Pt 1):1093-6.McDonald MM, et al. Assessment of Microscopic Hematuria in Adults. American family physician. Vol. 73 No. 10 May 15, 2006 McTavish JD, et al. Genitourinary Imaging: Multi–Detector Row CT Urography: Comparison of Strategies for Depicting the Normal Urinary Collecting

System. Radiology 2002;225:783-790.Memarsadeghi M, et al. Unenhanced Multi–Detector Row CT in Patients Suspected of Having Urinary Stone Disease: Effect of Section Width on

Diagnosis. Radiology 2005;235:530-536.Pearle MS, et al. Urologic diseases in America project: urolithiasis. J Urol 2005; 173:848.Pfister SA, et al. Unenhanced helical computed tomography vs intravenous urography in patients with acute flank pain: accuracy and economic

impact in a randomized prospective trial. Eur Radiol. 2003 Nov;13(11):2513-20. Epub 2003 Jul 24. Portis AJ. Diagnosis and Initial Management of Kidney Stones

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177:1285-1291.

Sandhua C, et al. Urinary Tract Stones—Part I: Role of Radiological Imaging in Diagnosis and Treatment Planning. Clinical Radiology. Volume 58, Issue 6, June 2003, Pages 415-421

Sierakowski B, et al. The frequency of urolithiasis in hospital discharge diagnoses in the United States., Invest. Urol. 15 (1978), p. 438.

Sudah M, et al. MR Urography in Evaluation of Acute Flank Pain: T2-Weighted Sequences and Gadolinium-Enhanced Three-Dimensional FLASH Compared with Urography. AJR 2001; 176:105-112

Sudah M, et al. Genitourinary Imaging: Patients with Acute Flank Pain: Comparison of MR Urography with Unenhanced Helical CT. Radiology 2002;223:98-105.

Sheafor DH, et al. Nonenhanced Helical CT and US in the Emergency Evaluation of Patients with Renal Colic: Prospective Comparison. Radiology. 2000;217:792-797

Smith RC, et al. Acute flank pain: comparison of non-contrast-enhanced CT and intravenous urography. Radiology 1995 Mar;194(3):789-94.

Teichman J. Acute Renal Colic from Ureteral Calculus. NEJM Volume 350:684-693 February 12, 2004.Uribarri J et al. The first kidney stone. Ann Intern Med 1989 Dec 15;111 (12):1006-9.Urologic Clinics of North America. Pathogenesis of Renal Calculi. Volume 34, Issue 3 (August 2007) Varanelli MJ, et al. Relationship Between Duration of Pain and Secondary Signs of Obstruction of the

Urinary Tract on Unenhanced Helical CT AJR 2001; 177:325-330Zagoria, et al. Abdominal Radiography After CT Reveals Urinary Calculi: A Method to Predict Usefulness of

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