This document discusses urolithiasis, or kidney stones. It begins by introducing kidney stones as the third most common pathology after UTIs and prostate issues. It then covers the pathogenesis, risk factors, classifications, varieties, clinical features, evaluations, and treatments of kidney stones. Key points include that calcium stones make up 70-80% of cases, struvite and cystine stones are also common, risk factors include diet, fluid intake, family history, and medical conditions. Evaluations involve urinalysis, imaging like ultrasound or CT, and stone analysis. Treatments depend on stone location and size, with drainage for infected or obstructed cases.

1. UROLITHIASIS
PRESENTED BY: MOHAMMAD MASOOM PARWEZ
MODERATOR: DR. BHARATI PANDYA

2. INTRODUCTION
• 3rd most common pathology following UTI and prostate
• Prevalence – increasing
• Peak age – 4th to 6th decade
• M:F - 2:1
• Recurrence rate – as high as 50% in 5 years*
• Struvite stones – H.C.G. von Struve (Russian naturalist); previously
“guanite” (bat droppings)
• Ca oxalate dihydrate – “Weddellite” – resembles sea floor of Weddell
sea in Antarctica

3. PATHOGENESIS
• Physical and chemical properties of urine
• Supersaturation of urine with solutes
• Depletion of stone inhibitors (citrate, phosphate, magnesium)

4. Risk factors
• Crystalluria:
• Ca oxalate dihydrate: bipyramids
• Ca oxalate monohydrate: biconcave oval/ dumbbell
• Cystine crystals: hexagonal
• Struvite: coffin lids
• CaHPO4 brushite stones: splinter like
• Ca apatite and uric acid crystals: amorphous powder
• Socioeconomic status:
• More common in affluent, industrialized countries

5. Risk factors
• Diet:
• High saturated and unsaturated fatty acids
• High animal protein and sugar
• Less dietary fiber, vegetable protein and unrefined carbs
• High dietary sodium
• Fluid intake and urine output
• Occupation:
• Sedentary lifestyles
• Climate:
• Hot climate- dehydration- more UV light – more vit D3 production

6. Risk factors
• Family history:
• Positive family history: twice likely to have stone
• Medication:
• Triamterene
• Antacids containing silica
• Carbonic anhydrase inhibitors
• Protease inhibitors
• Diseases:
• Hyperparathyroidism
• Renal tubular acidosis (partial/complete)
• Jejuno-ileal bypass
• Crohn’s disease,
• Intestinal resection
• Malabsorptive conditions
• Sarcoidosis
• Hyperthyroidism

7. Risk factors
Anatomical abnormalities associated with stone formation:
• Tubular ectasia (medullary sponge kidney)
• Pelvi-ureteric junction obstruction
• Calyceal diverticulum
• Calyceal cyst
• Ureteral stricture
• Vesico-ureteral reflux
• Horseshoe kidney
• Ureterocele

8. Classification
• Calcium Stones 70-80%
– Ca Phosphate 5-10%
– Ca Oxalate/Phosphate 30-45% (Mixed)
– Ca Oxalate 20-30%
• Struvite stones 15-20%
• Cystine stones -3%
• Uric acid stone
• Xanthine stone

10. ETIOLOGY
• Poly-crystalline aggregates of crystalloid and organic matrix
• Super-saturated urine – depends on urinary pH, ionic strength, solute
concentration and complexation
• Crystal inhibitors like magnesium, citrate and pyrophosphate inhibits
active crystal growth

11. THEORIES
• Nucleation theory – stones originate from crystals / foreign bodies
immersed in supersaturated urine
• Crystal inhibitor theory – stones formed due to absence or low
concentration of inhibitors

12. ETIOLOGY
Crystal stones –
• Nucleation –
• initiates the stone process
• induced by proteinaceous matrix, crystals and foreign bodies
• heterogenous nucleation requires less energy and may occur in less saturated
urine
• Crystals of one type serve as a nidus for another crystal with similar lattice,
eg: uric acid crystals initiating ca oxalate formation
• Growth
• Aggregation

13. ETIOLOGY
• THEORY OF MASS PRECIPITATION:
• Suggests that collecting tubules become plugged with crystals – stasis –
further stone growth
• FIXED PARTICLE THEORY:
• Formed crystals are retained within cells or beneath tubular epithelium

14. ETIOLOGY
• Matrix stones:
• non crystalline, matrix component of urinary stones comprises predominantly
of protein, with small amounts of hexose and hexosamine
• Associated with previous kidney surgery or chronic UTI; gelatinous texture
• Histology: laminations with scant calcifications
• Radiolucent on x rays
• NCCT reveals calcifications
• Serves as nidus for crystal aggregation

15. STONE VARIETIES
• Calcium:
• 80-85% of all stones
• Causes – elevated urinary calcium,
elevated urinary uric acid, elevated urinary
oxalate, decreased urinary citrate
• Symptoms develop secondary to
obstruction with resultant pain, infection,
nausea and vomiting
• Nephrocalcinosis – calcification of renal
parenchyma; frequently found in RTA and
hyperparathyroidism Ca Oxalate “mulberry stone”

16. STONE VARIETIES
Calcium:
• Absorptive hypercalciuric nephrolithiasis
• Secondary to increased calcium absorption from the small bowel- increased
load of calcium filtered from the glomerulus – suppression of PTH –
decreased tubular reabsorption of calcium – hypercalciuria (>4mg/kg)
• Resorptive hypercalciuric nephrolithiasis
• 10% of patients with obvious primary hyperparathyroidism
• Commonly seen in women
• Hypercalcemia with elevated PTH – diagnostic
• Treatment – surgical removal of adenoma

17. STONE VARIETIES
Calcium:
• Renal induced hypercalcemia
• Intrinsic renal tubular defect of calcium excretion
• Hyperuricosuric calcium nephrolithiasis
• Hyperoxalouric calcium nephrolithiasis
• Hypocitrate calcium nephrolithiasis

18. STONE VARIETIES
Struvite:
• Composed of Magnesium ammonium phosphate
• Commonly in women
• Presents as renal staghorn
• Infection stones due to urea splitting organisms like Proteus,
Klebsiella, Pseudomonas, Staphylococcus and Mycoplasma
• Alkaline urinary pH due to high ammonium concentration
• m/m: culture specific antibiotics; removal of catheters

20. STONE VARIETIES
Uric Acid:
• <5% of all calculi
• Common in men
• Patients with gout, myeloproliferative disease, rapid weight loss,
cytotoxic drug therapy have increased incidence
• Elevated urinary uric acid due to dehydration and excessive purine
intake
• Acidic urine pH<5.5
• Treatment – hydration, alkalinisation, restricting dietary purines,
Allopurinol

21. STONE VARIETIES
Cystine:
• Inborn error of amino acid metabolism including cystine, ornithine,
lysine, arginine
• Genetic defect chromosome 2p
• Classic cystinuria – AR inheritance
• 1-2% of all stones
• Peak incidence – 2nd or 3rd decade

22. STONE VARIETIES
• Family history of urinary stones
• X-ray – faintly opaque ground
glass, smooth edged stone
• Amber coloured stones with
hexagonal crystals
• m/m: high fluid intake, urinary
alkalinisation, low methionine
diet, penicillamine oral doses

23. STONE VARIETIES
Xanthine:
• Congenital deficiency of xanthine dehydrogenase
• Serum uric acid is low, hypoxanthine and
xanthine is high
• Stones are radiolucent, with tannish yellow color
• m/m: high fluid intake, urinary alkalinization

24. STONE VARIETIES
Indinavir:
• Protease inhibitor
• Radiolucent stones (6% of patients on drug)
• Only stone radiolucent on NCCT
• m/m: temporary cessation + iv hydration
• Tannish red, falls apart during basket extraction

25. STONE VARIETIES
Rare:
• Silicate: long term antacid use containing silica
• Triamterene: radiolucent, antihypertensive containing the drug;
discontinue medication

26. Clinical features
Pain
• Renal colic –
• stretching of collecting system/ureter
• Relatively constant, implies intraluminal origin
• Non colicky renal pain: distension of renal capsule
• Renal calculi – pain due to local mechanisms (inflammation, edema,
hyperperistalsis, mucosal irritation)
• Ureter: pain referred to ilio-inguinal and genital branch of
genitofemoral nerve
• Renal: flank and costovertebral angle

28. Clinical features
Hematuria
• Intermittent gross hematuria / occasional tea coloured urine
Infection
• Struvite stones common in infection
• Calcium phosphate stones
Fever
• Signs of urosepsis: fever, tachycardia, hypotension, cutaneous
vasodilatation
Nausea and Vomiting

29. Evaluation
History
• Nature of pain, onset, character, potential radiation
• Associated nausea, vomiting, gross hematuria
• h/o similar pain
• h/o medication
• Family history
• Diet

30. Evaluation
Physical examination:
• Acute renal colic – severe pain, attempting to find relief in multiple,
bizarre positions
• Tachycardia, sweating, and nausea
• Costovertebral angle tenderness
• Abdominal mass – long standing obstructive uropathy

31. Investigations

32. STONE WORK-UP
• To asses renal function and metabolic risk factors for stone formation
• Blood tests:
• Serum electrolytes and Serum Creatinine
• Serum Calcium
• Serum Uric acid
• Serum Phosphorus
• 24 hrs. urine collection for
• pH Creatinine
• Calcium Phosphorus and
• Oxalate Magnesium
• Uric acid Sodium
• Citrate Total volume
• Stone Analysis

33. Evaluation
Diagnosis :
Initial evaluation
• Urinalysis
• Urine culture
• Plain x-ray of KUB.
• Renal Ultrasound demonstrates the stone along with any hydronephrosis if present.
• Intravenous pyelography
• Axial spiral CT confirms the calculus, and demonstrates the exact degree of obstruction.

35. Urinalysis
• Gross or microscopic hematuria.
• Pyuria, may accompany
obstruction even in the absence
of identifiable infecting
organisms.
• Severe pyuria is present,
infection should be considered
(especially in a female), since the
stones may be secondary to
infection.

36. A x ray KUB showing stones in rt kidney

37. A USG showing acoustic shadow produced by
kidney stone

38. Intravenous pyelography
• Excretory pyelography –
information about function of
kidney and location of stone
• Contra-indicatons -
• allergy to contrast media
• S-creatinine level > 200 µmol/L
• On medication with metformin

39. Non-contrast CT
• Advantages: fast and non invasive, gives accurate location of stone
• Disadvantages: specificity/sensitivity low for other pathologies (AAA,
appendicitis)
• Does not evaluate renal function or degree of obstruction

40. CT Urography
• Advantages: Renal function
• Disadvantages: uses Renal contrast media ( allergy, nephrotoxic)
• - Normal BUN, Creatinine require before RCM
• - Metformin & RCM severe Lactic acidosis, nephrotoxicity
• -False negative if stone small, radiolucent, partially obstructing, or
passes into bladder before contrast passed by kidneys

41. Cystoscopy
Cystoscopy shows swelling of the
ureter orifice in lower location of
the stone, it may also partially
project out to the orifice.

42. STONES OF THE URINARY TRACT
• Treatment :
• Depends on size, location, degree of obstruction and patients clinical status
• Patients with infection or high grade obstruction require prompt intervention in
the form of retrograde ureteral catheter or percutaneous nephrostomy drainage
• About 90% of ureteral calculi measuring less than 4 mm pass spontaneously
whereas only 20% of calculi measuring more than 6 mm pass
• Expectant treatment is indicated in asymptomatic, non obstructed, non infective
with stone size less than 4 mm diameter in the lower third of ureter

43. STONES OF THE URINARY TRACT
• Drink copious amount of water, four to six weeks duration is allowed for passage
of stone
• Stone extraction is indicated for uretral stones that do not pass spontaneously
• Small stones may be grasped directly or engaged in stone basket and extracted
• Larger stones may be fragmented using
• ultrasound
• electrohydraulic
• pneumatic
• laser lithotripsy

44. STONES OF THE URINARY TRACT
• Shock wave lithotripsy : ureteral stones less than 8 mm diameter
• it may be performed with or without a stent as long as stone can be adequately visualised
• Ureterolithotomy is rarely needed given the high success rate of non- operative
and minimally invasive technique like SWL, ureteroscopy and laparoscopy

45. Pain relief during acute colic-
• Pain relief involves the administration by various routes of the
following agents:
• Diclofenac sodium
• Drotaverine
• Hydromorphone hydrochloride + atropine sulphate
• Tramadol
• OTHER MEDICATIONS-
• Tamsulosin increases peristalsis of ureter
• Phosphodiesterase inhibitors- Dutasteride

46. Pain relief
• Not responding to analgesics:
drainage by stenting or
percutaneous nephrostomy (PN) or
stone removal should be carried out

47. Management
• Average time to pass stone varies (7-20 days)
• Long acting CCB (Nifedipine) and steroids may enhance passage
• F/U Urology in 7 days
• Stone saved/submitted to urologist for analysis.
• Return immediately if intractable, severe pain, persistent nausea and
vomiting, fever and chills

48. Indications for Admission
• Obstruction with infection
• Persistent pain
• Persistent nausea and vomiting
• Urinary extravasation
• Hypercalcemic crisis

49. Indications of surgery
• Frequent attacks of the renal colic or persistent pain that disables the patient
• Obstruction - hydronephrotic degeneration of the kidney
• Obstructive anuria
• Frequent attacks of the acute pyelonephritis
• Gross hematuria
• Calculous pyonephrosis
• Stone in the ureter of the sole kidney that won’t pass away spontaneously

50. Extracorporeal Shock Wave Lithotripsy
• An extracorporeal noninvasive
technique that uses shock waves to
disintegrate urinary calculi while the
patient is immersed in a water bath
• With this technique, calculi in the
upper urinary tract are reduced to
fragments, which pass spontaneously
from the collecting system and
bladder in most patients

51. ESWL

52. Steinstrasse (Stone street) - post ESWL

53. ENDOSCOPIC PROCEDURES
• Cystoscopic technique
stones in the distal ureter and
bladder can sometimes be
removed with a wire stone
basket.Removal of bladder stones
termed as cystolitholapexy
• Ureteropyeloscopy
With this technique, small stones
can be easily trapped in a stone
basket and safely extracted through
the dilated ureter

54. Percutaneous nephrostomy
• This technique, along with refinements in
endoscopic instruments and advances in
fiberoptics, allows endoscopic manipulation
in the upper urinary tract by the
percutaneous approach
Laparoscopic procedures
• Pyelolithotomy done for pelvic stones and
lap ureterolithotomy done for mid ureteral
stones

55. Open Surgical Procedures
• Pyelolithotomy: Simple pyelolithotomy
is used for removal of calculi confined
to the renal pelvis
- This procedure is not indicated for the
removal of entrapped caliceal stones or
large, branched renal calculi

56. Open Surgical Procedures
• Ureterolithotomy-
-There are retroperitoneal,
transperitoneal and combined
surgical accesses. It depends on
stone location

57. Open Surgical Procedures

58. Complications
• Ureteral scarring and stenosis
• Nidus for infection
• Serious infection of the kidney that diminishes renal function
• Urinary fistula formation
• Ureteral perforation
• Extravasation
• Urinary outflow obstruction
• Hydronephrosis
• CRF

59. Summary

61. Summary

63. Summary

64. PREVENTION

68. REFERENCES
• Sabiston Textbook of Surgery , 20th edition
• Smith and Tanagho’s General Urology , 18th edition
• Guidelines on Urolithiasis – European association of Urology, 2015

69. Thank You