Management of urolithiasis
- 1. Presentation on Pathology and Management of Urolithiasis By Dr Ahmed Yakubu
- 2. OUTLINE: Introduction Pathophysiology Management - History - Examination - Investigation - Treatment Prevention Conclusion Bibliography
- 3. INTRODUCTION Urolithiasis is the occurence of stones (calculi) in the urinary tract. Urolithiasis affects all geographcal, cultural, and racial groups. The lifetime risk of occurrence of urolithiasis is generally higher in hot climates and also reflects dietary habits in different regions which is also reflective higher incidence of specific kinds of stones in diferent regions.
- 4. Types: 4 Most Commonly Encountered calculi: i. Calcium Stones ii. Urate stones iii. Magnesium ammonium phosphate stones (struvite) iv. Cystine stones
- 5. Epidemiology A study done in South-eastern (Enugu) state of Nigeria by I. A. Meka et al. showed that bladder stones constituted the majority of renal stones encountered in their tertiary center (A two-center study) 58%, mean age 37.3 (9.5years) and M:F = 5.3:1 A 5-year review done in the south-western (Lagos) state tertiary hospital by Olufunmilade Omisanjon et al. showed that bladder stones constituted the majority of renal stones 48.7%, mean age 49.13 (16.27 years) and M:F = 1.8:1 Generally significant proportion of statistics globally shows higher incidence in dry/hot regions or regions with scarcity of water, Male > Females and commoner in young age group.
- 6. Anatomy Retroperitoneally: - Kidneys and its vessels - Proximal ureter Dimensions: 12 x 6 x 3cm Average renal pelvis: <5mls Dermatome of pain fibres: T12 - L1
- 7. Avascular Plane of Brodel
- 8. - 25cm - Diameter 3mm with 3 constricted areas as illustrate - Lies anterior and slightly medial to tips of the transverse processes from L2 to L5 - Enters pelvis opposite the sacroiliac joints - Runs forward and medially at the level of the ischial spine
- 9. Male: 15 to 20cm Membranous part: least distensible and narrowest Female: 4cm
- 10. PATHOPHYSIOLOGY Calcium Stones 1. Hyperoxaluria - Primary hyperoxaluria: AGT enzyme: converts glyoxylate into glycine Deficiency of GH/HPR: converts glyoxylate into glycolate Lactate dehydrogenase: converts accumulated glyoxylate into oxalate
- 11. PATHOPHYSIOLOGY - Secondary Hyperoxaluria Enteric Hyperoxaluria: GI related conditions such as celiac disease, crohns disease, pancreatitis, biliary diseases, low dietary calcium or short bowel syndrome; gastric bypass. Dietary Hyperoxaluria: (24% - 53%) Leafy green (especially spinach and rhubarb), chocolate, cocoa, black tea, nuts, peanut butter , or starfruit, may increase serum, urine oxalate levels.
- 12. PATHOPHYSIOLOGY 2. Hypercalciuria: Defined by urinary calcium in excess of 250mg in females; 300mg/day in males or 4mg/kg/day Defective Calcium Handling: - Transcelluar Route: Apical entry via TRP calcium channel and L-type calcium channel; Intracellular buffering + shuttling via Calbindin; basolateral transport via PMCA and NCX1. - Paracellular Route: Paracellular claudin protein; NKCC2/ROMK channel; NHE3; CaSR.
- 13. PATHOPHYSIOLOGY *With excessive GI absorption and/or defective renal reabsorption hypercalciuria ensues thus absorptive hypercalciuria or renal leak hypercalciuria occurs. - Renal phosphate leak hypercalciuria: Defective NPT2a - Resorptive Hypercalciuria: Hyperparathyroidism
- 14. PATHOPHYSIOLOGY Hyperuricaemia/Hyperuricaemia: In acidic media with pH <5.5 nearly 100% of uric acid is in the undissociated form. Precipitating factors - Low urinary pH: Primary gout, Dehydration, Familial, IBD, Obesity, DM, Metabolic syndrome - Elevated urinary uric acid: High purine-rich diet, myeloproliferative Dxs, In-born errors of metabolism (HGPT deficiency, PRPS superactivity, G6PD deficiency), and medications.
- 15. PATHOPHYSIOLOGY Cystinuria: rBAT and b0,+AT cystine transporter are defective due to SLC3A1 and SLC7A9 genetic mutation Magnesium ammonium phosphate calculi: Urea splitting organisms result in the generation of ammonium, bicarbonate and carbonate. In alkaline media the dissociation potential of struvite salts reduces.
- 16. PATHOPHYSIOLOGY The Balance! Metastable supersaturated state vs unstable saturated state of urine Simple crystalluria vs crystal aggregation (epitactic induction of crystallization)
- 17. PATHOPHYSIOLOGY Inhibitors - Inorganic pyrophosphate (calcium phosphate) - Diphosphonates (calcium oxalate) - Urinary citrate and magnesium - Glycosaminoglycans; urinary prothromin fragment 1; osteopontin; Tamm horsfall protein Promoters: - High urinary calcium, oxalate, sodium and uric acid - Low urine volume - Stasis/urinary tract obstruction
- 18. PATHOPHYSIOLOGY The pain - Nerve endings and chemoreptors in the submucosa tract - Stretching and irritation of tract - Acute dilatation - Reflex Spasm - Migration of calculi - Reactive inflammationwith (edema formation) - Proximal hyperperistalsis ?Infection
- 19. PATHOPHYSIOLOGY Most acute pain subside after 24hrs and further in following weeks in the absence of infection or stone movement: - Ureteral hyperperistalsis diminishes - Renal blood flow diminishes - Decline in urine production - autoregulatory/reflex retrograde pyelovenous and pyelolymphatic drainage - Reduction in proximal hydrostatic pressure and pain - ?Pericalculous leakage
- 20. MANAGMENT - History: Complain: *Pain Hematuria Irritative/obstructive urinary tract symtoms (LUTS) Features of urosepsis Features renal decompensation
- 21. History Pain character and associations - Pelvo-calyceal calculi - Proximal ureteral calsuli - Mid ureteral - Distal ureteral - Bladder stones
- 22. Differential Diagnosis Left: Pancreatitis PUD Diverticulitis Right: Cholecystitis Appendicitis Biliary colic Papillary necrosis Pyelonepritis Acute scrotum Cystitis Renal cell carcinoma Prostatic diseases Renovascular disorders *Abdominal aortic aneurysm
- 23. Conditions associated with increased risk of urolithiasis: - Intestinal resection - Hyperparathyroidism - Spinal cord injury - Hyperthyroidism - Renal tubular acidosis - Jejunoileal bypass - Crohn’s disease - Malabsorptive conditions - Sarcoidosis
- 24. Medications associated with stone formation - Acetazolamide - Sulphonamides - Triamterene - Indinavir
- 25. Complications: - Intractable pain - UTI/Urosepsis - Calculous Hydronephrosis - Calculous pyonephrosis - Renal failure (Long standing obstruction) - Squamous cell carcinoma - Perinephric abscess - Perforation + extravasation
- 26. Examination - Diaphoretic - Restless - Costovertebral tenderness - Tender testicles but not pathologic - Vitals: Tachycardia + Elevated BP - Fever IN THE SETTING OF URINARY INFECTION
- 28. KUB Radiograph Radioopaque: 85% of upper urinary tract calculi - Calcium stones - Struvite stone Relatively radiolucent: - Uric acid stones - Indinavir stones - ?Cystine stones
- 29. Differetials of calcifications on KUB Radiograph: - Gall stones - Costal cartilage calcifications - Calcified adrenals - Phlebolith - Fecolith - Calcified lymph nodes
- 30. Ultrasonography - Low sensitivity for ureteral stones - Recommended as first line in pregnancy - Pediatric cases - May be utilized in follow-up monitoring of calculi migration - Can reveal obstructions
- 31. Intravenous Urography - Outines the urinary tract - Reveals anatomical anomalies - Gives an idea of renal fuction - Useful in extensive extrarenal calfications - Reveal non-opaque calculi Draw backs: - Nephrotoxicity - Allergy - TAT - False negatives
- 32. Anatomical abnormalities associated with stone formation - Medullary stone kidney - Horseshoe kidney - Pelvo-ureteral junction obstruction - Caliceal diverticulum - Caliceal cyst - Ureterocele - Ureteral stricture - Vesico-ureteral reflux
- 34. FBC + Differentials E/U/Cr; Ca2+, PO4 -3 and Albumin Urine microscopic Urine culture & sensitivity testing
- 35. 24 Hour Urine Profiling: Objective indications: - Initial presentation with multiple calculi - Urolithiasis with renal failure - Solitary kidney - family history of urolithiasis - More than one case of urolithiasis in a year - Bilateral calculi Commonest findings: Hypercalciuria, hyperoxaluria, hyperuricosuria, hypocitraturia and low urinary volume
- 36. 24hour Urine Analysis Volume: 2500mls/day; Urine creatinine: 18 to 24mg/kg for male 15mg to 20mg/kg for female. pH 5.7 to 6.3 Hypercalciuria: >300mg/24 hour in men >250mg/24 hour in women Hyperuricosuria: >800mg/24hour in men >750mg/24 hour in women Hypocitraturia: <320mg/24 hour (1.67mmol/24hour) Hyperoxaluria: >40mg/24hour *Other parameters routinely included are urinary potassium, sodium and magnesium levels.
- 37. Treatment: Emergency Care: - Excruciating Pain!!! - Adequate analgesic: Stat dose of opoids, subsequent doses for breakthrough pain; NSAIDs maintenance. - Antiemetic - Hydration - Investigate: ?Position ?size ?number ?complications ?comorbid conditions
- 38. Non-operative Treatment Conservative therapy - Active MET: Out-patient care in the post-acute phase Favourable factors: Lower ureteric stones <10mm (<5mm) Reasonable pain control Normal kidney function Sterile urine A preferred approach in pregnancy and pediatrics
- 39. Active MET Enhances chance of spontaneous passage Reduces surgically related complications General Interventions: - Enhanced fluid intake with output goal of >2.5/day - Reasonable analgesia - Alpha RBs - CCB: nifedipine - Avoid prolong period of recumbencys - Restricted sodium/protein intake - Enhanced intake of citrate rich meals - Magnesium supplements
- 40. Active MET continues Hyperoxaluria: General interventions No calcium restriction Hypercalciuria: General interventions Thiazide diuretics Cystine calculi: General interventions Chelating agents: MPG/D- pencillamine Urate calculi: General interventions Allopurinol Alkalinization of urine (Likewise in cystine calculi)
- 41. Active MET continues Follow up: 14days - Regular image monitoring - Monitoring of renal function - Monitoring of sterility of urine - Use of urinary strainer at all times - Report if worsening of symptoms/onset of warning symptoms
- 42. Active MET continues Contraindications to conservative management: - Occupation: Pilot - Deteriorating renal function - UTI - Intractable pain - Ureteral obstruction in solitary kidney/transplated kidney
- 43. Extracoporeal Shockwave Wave Lithotripsy A system utilized to fragment renal calculi via generation and focusing of shock waves using a lithotripzer guided by a localization device. 4 Components: - Energy source (electromagnetic, electrohydraulic and piezoelectric) - Focusing device - Coupling medium - Localization system via fluoroscopy/ultrasonography
- 44. Features favouring use ESWL: <3mm Solitary calculi Location: upper/mid pole calculi & proximal ureter Calcium stones Normal anatomy *May be used as adjuvats to PCNL/URS
- 45. Unfavourable conditions: Extreme of ages Morbid obesity Lower pole calculi Obstruction *The reverse of favourable conditions
- 46. Contraindications: - Patient with pacemakers/defibrilators implants - Pregnancy - Cytine stones - Calcium oxalate calculi >2.5cm/Struvite >5cm - Starghorn calculi - Calcified aortic aneurysm within 5cm of focus - Renal artery aneurysm - Urosepsis
- 47. Complications: Ureteric stricture Incomplete stone fragmentation and obstruction Urosepsis Arrythmias perirenal hematoma pancreatitis
- 48. Operative Management Stenting and Percutaneous Nephrostomy: *Obstructions and/or Infections - Persistent pain - Pyonephrosis - Anuria - Solitary kidney prior to ESWL - Infected hydronephrosis
- 49. Percutaneous Nephrolithotomy - Failed ESWL - Cystine calculi - Patient with pacemakers or defibrilators implants - Calculi with abnormal anatomy - Lower pole calculi<10mm *Absolutely contraindication: Coagulopathy - Calculi >2cm - Renal artery aneurysm - Proximate calcified aortic aneurysm - Renal pelvic calculi/proximal ureteral calculi
- 50. Uretero-renoscopy + Lithotripsy - Most suited for calculi >1.5cm - Cystine calculi - Upper pole calculi - Lower pole calculi <10mm - Combined Renal + ureteric calculi
- 51. Pyelolithotomy: - Surgical removal of calculi in the pelvi-calyceal complex Nephrolithotomy: - Surgical removal of calculi deep in the renal parenchyma Indications: - Failed or unavaibility of ESWL/PCNL/URS+Lithotripser - Co-existing pathology necessitating approach *Necessary in less than 3% cases of urolithiasis *Lateral approach/Dorsal lumbotomy
- 52. Nephrectomy: Non-functional/poorly kidney(s) - GFR <15ml/min/1.73m2 - <10 to 15% Functional capacity Ureterolithotomy: - Removal of calculi via an incision through the ureter - Fading out of practice
- 53. Bladder calculi: Transurethral cytolitholapaxy Percutaneous suprapubic cytolitholapaxy Open suprapubic cystotomy *Contraindicated only in unstable or near-terminal asymptomatic patients *ESWL - not so effective in bladder calculi cases
- 54. PREVENTION - High fluid intake - Restricted dietray salt intake - Caution with diet high in purine - Increase citrus fruit intake
- 55. CONCLUSION The understanding of the pathogenesis of urolithiasis is a growing area in urology that delves deeper with each unveiling understanding of the process. Its mangement spans from non-operative active MET and ESWL interventions to temporizing measures such as stenting/percutaneous nephrostomy to corrective minimally invasive interventions.
- 56. BIBLIOGRAPHY - MedScape - Nephrolithiasis by Chirag N Dave - A comprehensive approach to long cases in surger - approach to patient with gross hematuria, urinary calculi by Emeka Kesieme - 2007 guidelines for management of ureteral calculi by EAU/AUA Neprolithiasis guideline panel - Inhibitors and promoters of stone formation by Herbert Fleisch - Textbook of Medical biochemistry for medical students by DM Vasudevan - Last’s anatomy - regional and applied, part 11 by Chummy S. Simmatamby