1. “Advances in Stone Disease Management”
Innovative Treatments
Exceptional Service
Superior Outcomes
“Advances in Stone Disease Management”
Casey McCullough, DO, MBA, FACOS

2. Disclosures
None

3. Learning Objectives
Identify the factors that increase the risk for sepsis and urgent Urologic management in the stone patient
Understand the evaluation of patients presenting with renal colic and irritative urinary symptoms manifesting as stone disease
Discuss the surgical approaches available in treating renal, ureteral, and bladder calculi

4. Stone Disease Prevalence approximately 9% of U.S. population
Annual U.S. cost burden - $5 Billion dollars!
Prevention is the cornerstone of all therapy
Acute surgical intervention for the symptomatic patient
Constant improvement in Endoscopic technology

5. Epidemiology Incidence of stone disease peaks in 4th to 6th decade
Men historically have 2 or 3 times the risk than women
Caucasian men/women have highest risk
African-American men and Asian women have the lowest risk
Dramatic increase in the pediatric population, possibly related to childhood obesity

6. Environmental Factors
Hot, dry climates
Highest prevalence of stones is in the Southeast
Occupations with exposure to excessive heat
Conditions that promote dehydration

7. Systemic Factors Obesity, weight gain, metabolic syndrome
Type II Diabetes, Insulin Resistance, Dislipidemia, HTN
Woo Y, et al. Metabolic Syndrome and Kidney Stone Disease: A Systemic Review. J Endourol, 30(3), March 2016,

8. Calcium Stone Disease RISK FACTORS: ↓ urine volume ↓ or ↑ urine pH
↑ urinary excretion of calcium, oxalate, & uric acid
↓ urinary excretion of citrate

9. Urine Evaluation
Urinalysis – presence of crystals can be pathognomonic for stone composition
Hexagonal – Cystinuria ; Coffin-Lid – Struvite
Urine Culture: Urease splitting organism (proteus, klebsiella) – struvite stones
Urine pH
pH < 5.5 = uric acid stones
pH > 7.0 = struvite or calcium phosphate stones

11. Metabolic Evaluation

13. Radiographic Evaluation
Historically plain abdominal radiography and intravenous pyelography
Renal Ultrasound
Unenhanced Helical CT scan: stone burden, collecting system anatomy, location, extravasation, stranding
Hounsfield Unit density (HU): 1,000 HU
Skin to Stone Distance (SSD): >10cm

14. Radiographic Evaluation

15. The Acute Stone Episode
History and Physical Examination: Fever >100F, Tachycardia, Hypotension: concern for impending Sepsis
Laboratory Evaluation: CBC, BMP, blood cultures, urine culture
Radiographic evaluation
Pain control: NSAIDs and Opioid analgesics. Ketorolac. NSAIDs directly inhibit prostaglandins, decreasing activation of pain receptor, reducing renal blood flow and ureteral contractions.

16. The Acute Stone Episode
Management of ureteral obstruction in the septic patient is urgent decompression of the collecting system
Ureteral Stent
Nephrostomy tube placement (PCN)

17. Medical Expulsive Therapy (MET)
No signs of infection, normal renal function, well-controlled pain, reasonable likelihood of spontaneous stone passage
Tamsulosin 0.4mg daily (off label, intra-operative floppy iris syndrome, hypotension, nasal congestion)
Length of time using MET is patient dependent

18. Shock Wave Lithotripsy (ESWL)
Physics: repetitive administration of shock waves, with both positive and negative pressure components, creates small fractures in the targeted stone.
2,500 to 3,000 shocks during a treatment session leads to stone fragmentation
Electrohydrolic (EHL), Electromagnetic, and Piezoelectric generators
Imaging: Fluoroscopy or Ultrasound technology

19. Shock Wave Lithotripsy (ESWL)
Indications: Location of stone within the kidney. Lower pole stones have lower success rate.
Location in the Ureter decreases stone free rate. 72% ESWL vs 90% URS
Not recommended for distal ureteral stones because lower stone free rates
Ureteral stenting not required
Stone size is greatest predictor of SWL success. As stone size increases, SWL success rates decline. In general, stones <10mm

20. Shock Wave Lithotripsy (ESWL)
Stone Composition affects the ease at which it fragments with SWL
Cystine (Most Resistant)
Brushite
Calcium oxalate monohydrate
Struvite
Calcium oxalate dihydrate
Uric acid stones (Least Resistant)

21. Shock Wave Lithotripsy Acute Complications
Renal Injury: Hematoma, contusion. 1-20%
Nearly all patients post ESWL will have some degree of gross hematuria
Steinstrasse: “street of stones”, the accumulation of stone fragments in the ureter post ESWL. Stent placement does NOT reduce occurrence!
HTN: increased age >60yrs old associated with higher risk of development
DM: one retrospective long term study
Pregnancy: absolute contraindication

22. Shock Wave Lithotripsy Acute Complications

23. Percutaneous Nephrolithotomy (PCNL)
Reserve for large (>2cm) & complex stones, Staghorn calculi, or stones with complex renal anatomy
All patients need a sterile urine culture prior or been treated with culture specific antibiotics
Percutaneous kidney access obtained through a posterior calyx
Lithotripsy performed through rigid nephroscope and ultrasonic/pneumatic technology

24. Percutaneous Nephrolithotomy (PCNL)

25. PCNL Complications
4 – 61%
Septic – bacteremia occurs up to 37% post-op, 74% rate of post-op fever
Hemorrhagic – 0.4 – 11%. If delayed: pseudoaneurysm, AV fistula, or segmental renal artery injury
Visceral injury: pleura, liver, spleen, colon, duodenum
What is the irrigant of choice for all upper endoscopic urologic procedures?

26. PCNL Video

27. Semi-Rigid Ureteroscopy (URS)
Generally used to treat ureteral stones below the iliac vessels
Safety wire used to maintain access
Stones can be basket extracted or broken up with Holmium laser fiber
Flexible quartz fiber, 150-1,000 microns, photothermal direct contact
Usually requires ureteral stent placement afterwards

28. Semi-Rigid Ureteroscopy (URS)

29. Semi-Rigid Ureteroscopy Complications
Perforation: terminate the procedure and place a ureteral stent
Extrusion of stone fragments
Avulsion: <1% risk
Infection / Sepsis
Stricture: 0.5-4% risk. Risk factors include impacted ureteral stone and/or ureteral injury

30. Semi-Rigid Ureteroscopy Video

31. Flexible Ureteroscopy
Used to treat all appropriate renal calculi or ureteral stones above the iliacs
Staged procedures to treat large renal stones >2cm
Smaller working channel than semi-rigid ureterscopes (3.6Fr)
Post-operative stent placement
Similar complications to semi-rigid ureteroscopy

32. Open/Laparoscopic/Robotic Stone Surgery
Anatrophic Nephrolithotomy
Pyelolithotomy
Caliceal Diverticulolithotomy
Ureterolithotomy
Nephrectomy

33. Robotic Pyelolithotomy and Stone Extraction

34. Renal Calculi Staghorn Calculi Non-Staghorn, Non-Lower Pole
PCNL is first line therapy
Should NOT be observed if patient is healthy enough
Non-Staghorn, Non-Lower Pole
<2cm: URS or SWL
>2cm: PCNL

35. Selection of Therapy
Staghorn Calculi: PCNL is 1st line therapy. Should not be observed if healthy
Non-staghorn, Non-lower pole stones: Majority of renal stones. SWL or URS
50% of asymptomatic stones will progress (Elective surgery or observation)
Lower Pole Renal Calculi: SWL, URS, PCNL.
Superior stone free rates for URS for stones <2.5cm in size
Ureteral Calculi: URS
Bladder Calculi: holmium laser lithotriopsy or ultrasonic treatment

36. Conclusion of Surgical Management
Surgical management of stone disease should be tailored to the patient and the stone.
Certain patient and stone characteristics can preclude certain types of therapy

37. References

38. Medical Management
Involves the initiation of dietary measures and medications to reduce the risk of stone recurrence in
- Recurrent
- Interested first-time stone formers
Basis for recommendations may be empiric or based on stone composition

39. Calcium Oxalate and Phosphate
Increase fluid intake for a goal urine output >2.5 L daily
Avoid strict dietary calcium restriction
Consume the RDA of calcium
- Women <50 yrs and men <70 yrs – 1,000mg daily
- Women >50 yrs and men >70 yrs – 1,200mg daily
Limit sodium intake to <100 mEq daily
Oxalate-rich foods in moderation (spinach, potatoes, nuts, tea, chocolate)

40. Calcium Oxalate and Phosphate
Calcium intake modulates urinary oxalate excretion by binding oxalate in the intestine
Animal protein (red meat, fish, poultry, pork) confers an acid load that can reduce urinary citrate excretion & provides a purine load that increases urinary uric acid
Fruits and vegetables provide alkali, enhancing urinary citrate excretion

41. Pharmacologic Therapy - THIAZIDES
Promote net calcium reabsorption in distal renal tubule, thus reducing urinary calcium
Primarily for Hypercalciuric stone formers
Check 24 hour urine Ca+ levels (Litholink)
Hydrochlorothiazide, Chlorthalidone, Indapamide
Adverse Events: Hypokalemia, hypocitraturia

43. Primary Hyperparathyroidism
Always check PTH, uric acid, serum Ca+ levels
Primary hyperparathyroidism due to parathyroid adenoma are treated surgically

44. Uric Acid Stones
No RCT’s assessing effect of dietary or pharmacologic therapy
Low urine pH (<5.5) most common abnormality
Use Potassium Citrate (30-60mEq) to alkalinize urine
Use of Allopurinol rarely necessary: when pH >6.0, total uric acid concentration must exceed 1000mg/L to exceed solubility limits

45. Struvite Stones Magnesium, Ammonium, Phosphate stones
Dietary therapy with high fluid intake
Acetohydroxaminic acid: irreversible urease inhibitor to reduce urine pH and ammonia levels, but high side effect profile (HA, GI, anemia)

46. Cystine Stones Limit of solubility of Cystine is 250mg/L
Increase urine pH to with Potassium Citrate
Cystine-binding Thiol drug / Thiola / Alpha mercaptoproprionyl glycine (GI side effects, monitor CBC and LFTs)
Avoid high animal protein intake to limit cystine substrate methionine and prevent low urine pH

47. Follow-Up
Stone formers managed with diet and drug therapy should be monitored
- Imaging studies to identify growth or recurrence
- 24-hour urine to monitor response to therapy (Litholink)
Frequency of imaging and urine testing tailored to disease aggressiveness
- generally every 6 months

48. References
Borghi, L. et al., Urinary volume, water, and recurrences in idiopathic calcium nephrolithiasis: a 5 yr randomized prospective study. J Urol, (3): p
Pearl, MS, et al., Medical Management of Kidney Stones: AUA Guideline. J Urol, (2): p
Borghi, L. et al., Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria. N Engl J Med, (2): p

49. T. Casey McCullough, DO, MBA, FACOS
Snellville, Johns Creek, Lawrenceville, Decatur, Alpharetta, Sandy Springs, Athens, Dunwoody, Kennesaw
Thank You!
T. Casey McCullough, DO, MBA, FACOS
(860) cell
10730 Medlock Bridge Rd
John’s Creek, GA 30097
(678) office