1. URETERAL STONES: A Brief Review of Diagnosis and Treatment

2. EPIDEMIOLOGY 12% risk in lifetime 2-3% risk of renal colic
Recurs within 2-3 years
Occurs in men three times more than woman
Peak incidence from 30 to 50
Factors that may increase incidence: diet, lifestyle, social status, heredity, geography

3. TYPES OF STONES 75% calcium oxalate or phosphate
15% phosphate-containing, most commonly struvite (magnesium ammonium phosphate)
5-10% uric acid
1% cystine
Rarely, pure matrix and indinavir deposition

4. LOCATIONS OF STONES Ureteropelvic junction (UPJ)
Pelvic brim (at the bifurcation of the iliac vessels where the ureter courses anterior and medial to the vessels and is compressed)
Ureterovesical junction (UVJ)

5. URETERAL CALCULI

6. L1/L2 Junction
Tips of transverse processes
Stone
Sacroiliac joint
Curves medially,
Lateral to curve of sacrum
Enters bladder near
sacro-coccygeal junction.
Level with Ischial spines
Phlebolith

7. SIGNS AND SYMPTOMS
Severe, intermittent unilateral flank that radiates to the groin causing the patient to writhe around at its height of intensity
Microscopic hematuria
If febrile, then may be a complicated ureteral obstruction by either infection with obstruction or acute pyelonephritis

8. DIFFERENTIAL DIAGNOSIS
Genitourinary causes: pyelonephritis, torsion of a pelvic mass
Gastrointestinal causes: appendicitis, diverticulitis, cholecystitis, choledocholithiasis, pancreatitis, bowel obstruction, Crohn’s disease, torsion of an abdominal mass
Vascular causes: aortic dissection, ruptured abdominal aortic aneurysm

9. PLAIN RADIOGRAPHY
Relies solely on the identification of a calcific density along the expected ureteral tract
Only 59% of ureteral calculi are visible
Cystine stones are mildly radiodense
Uric acid, pure matrix, and indinavir stones are radiolucent

10. ULTRASOUND Not recommended
Detects indirect signs of obstruction: collecting system dilatation, a change in renal blood flow, a loss of a ureteric jet
Rarely identifies urolithiasis except at the UPJ or UVJ
Difficulty in measuring the size of a stone

11. INTRAVENOUS PYELOGRAM (IVP)
Advantages: availability, low cost, ability to assess renal function
Disadvantages: requires intravenous contrast, prolonged exam time, inability to assess other causes of the clinical presentation, difficulty in distinguishing calcific densities
Sensitivity 87% and specificity 94%

12. IVP: Radiographic Findings of Ureteral Stone Obstruction
Opacity along the urinary tract
Dilatation of ureter down to obstruction
Dilatation of collecting system
Delay in contrast of nephrogram
Delay in contrast of collecting system
Delay in contrast excretion

13. IVP: Radiographic Findings of Ureteral Stone Obstruction
Figure1. a. An opacity is visible within the pelvis on the right side. b. The right ureter is full of contrast down to the site of obstruction.

14. NONCONTRAST HELICAL CT (NCCT)
Imaging modality of choice
Advantages: speed, safety, ability to assess other causes of the clinical presentation, and in some places, equivalent cost to IVP
Disadvantages: Inability to assess renal function, difficulty in assessing patients that have insufficient renal fat, difficulty in distinguishing calcific densities
Sensitivity 95% and specificity 95%

15. NCCT: Direct Stone Visualization
Hallmark finding is a stone in the lumen of the ureter on the side of renal colic
Virtually all stones are seen on CT except pure matrix and indinivar stones

16. NCCT: Secondary Signs of Ureteral Obstruction
Ureteral dilatation
Collecting system dilatation
Perinephric stranding
Periureteric stranding
Nephromegaly
“Rim sign”
Absence of the white pyramids

17. MAGNETIC RESONANCE UROGRAPHY (MRU)
Identifies stones and some secondary signs of obstruction
Advantages: no radiation and contrast
Disadvantages: inability to image unobstructed urinary tract, expensive, slow
Figure 7. MRU show obstruction of the right ureter.

18. TREATMENT CONSIDERATIONS
URETERAL CALCULI
TREATMENT CONSIDERATIONS
Location
Size
Chronicity
Equipment
Expertise

19. URETERAL CALCULI TREATMENT OPTIONS Observation Shock wave lithotripsy
Ureteroscopy
Blind basket extraction
Percutaneous approach
Open surgery

20. CONSERVATIVE MANAGEMENT
Analgesics, hydration, and possibly antispasmodics
Follow plain radiographs at 1-2 week intervals

21. URETERAL CALCULI
SPONTANEOUS PASSAGE

22. URETERAL CALCULI SPONTANEOUS PASSAGE
Of all stones that pass spontaneously, 95% will pass within 6 weeks
Miller & Kane, 1999

23. URETERAL CALCULI
MEDICAL MANAGEMENT
Hollingsworth & Hollenbeck, 2006

24. URETERAL CALCULI
MEDICAL MANAGEMENT
Hollingsworth & Hollenbeck, 2006

25. INTERVENTIONAL MANAGEMENT: Current Therapy
Extracorporeal shock wave lithotripsy (for proximal ureteral stones and least invasive therapy)
Ureteroscopy (for mid and distal ureteral stones)

26. URETERAL CALCULI PARAMETERS FOR COMPARISON
Stone-free is not everything !!

27. PARAMETERS FOR COMPARISON
URETERAL CALCULI
PARAMETERS FOR COMPARISON
Effectiveness
Morbidity
Convalescence
Cost

28. DISTAL URETERAL CALCULI
COMPARISON OF MONOTHERAPY STUDIES
URS is % more effective than SWL (depending on type of SWL unit)
Morbidity / convalescence reduced with SWL
Need for stents 40-60% less with SWL
Cost issues not addressed in monotherapy studies

29. DISTAL URETERAL CALCULI
OVERVIEW OF HISTORICAL CONTROL STUDIES
SWL URS
Effectiveness Slightly better
Morbidity Less
Hospitalization Less
Cost Slightly less

30. DISTAL URETERAL CALCULI
PROSPECTIVE, RANDOMIZED TRIAL
80 patients randomized to receive SWL or URS 40 patients had stones > 5 mm 40 patients had stones < 5 mm
SWL performed on Dornier MFL 5000
URS performed with 6.5F or 9.5F semi-rigid ureteroscopes (basket vs. pneumatic lithotripsy)
Peschel & Bartsch, 1999

31. DISTAL URETERAL CALCULI
PROSPECTIVE, RANDOMIZED TRIAL STONES < 5 MM
URS SWL
OR time (min)
Fluoro time (min)
Stone-free (days)
Stent (days) 7.2 0
Re-treatment rate 0 15% * * * * *
Peschel & Bartsch, 1999

32. URETEROSCOPY

34. Ureteroscopy Easier for lower stones Extraction of stone fragments
Fragmentation
Laser Homium Yg
Mechanical EKL
Explosive EHL
Ultrasound
Risks

35. FLEXIBLE URETEROSCOPY
URETERAL CALCULI
FLEXIBLE URETEROSCOPY

36. URETERAL STONE MANAGEMENT
URETEROSCOPY
Advantages Highest success rate Definitive Rx - No waiting for stone passage
Disadvantages More invasive than SWL Higher complication rate Requires greater technical expertise

37. Rigid ureteroscope specifications include the following:
Tip diameter F (6.9F most common)
Optics - Fiberoptic bundles
Working channels - One, 2, or 3 (2 channels preferred)
Accessory length - Average, 40 cm

38. Flexible ureteroscope specifications include the following
Tip diameter F (7.5F most common)
Optics - Fiberoptic bundles
Working channel - Single, 3.6F
Access - Guidewire (0.035 in nitinol or in stainless steel)
Accessory length - Average, 100 cm

39. INTERVENTIONAL MANAGEMENT: More Invasive Treatments
Intracorporeal shock wave lithotripsy (through ureteroscope)
Percutaneous nephrostomy (for stones >2 cm and in proximal collecting system)
Laparoscopy (if complicated)
Open surgery (rarely done)

40. Thank you