Title: URETERAL STONES: A Brief Review of Diagnosis and Treatment
1URETERAL STONES A Brief Review of Diagnosis
and Treatment
2EPIDEMIOLOGY
- 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
3TYPES 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
4LOCATIONS 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)
5URETERAL CALCULI
6L1/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
7SIGNS 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
8DIFFERENTIAL DIAGNOSIS
- Genitourinary causes pyelonephritis, torsion of
a pelvic mass - Gastrointestinal causes appendicitis,
diverticulitis, cholecystitis, choledocholithiasis
, pancreatitis, bowel obstruction, Crohns
disease, torsion of an abdominal mass - Vascular causes aortic dissection, ruptured
abdominal aortic aneurysm
9PLAIN 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
10ULTRASOUND
- 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
11INTRAVENOUS 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
12IVP 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
13IVP 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.
14NONCONTRAST 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
15NCCT 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
16NCCT Secondary Signs of Ureteral Obstruction
- Ureteral dilatation
- Collecting system dilatation
- Perinephric stranding
- Periureteric stranding
- Nephromegaly
- Rim sign
- Absence of the white pyramids
17MAGNETIC 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.
18URETERAL CALCULI
TREATMENT CONSIDERATIONS
- Location
- Size
- Chronicity
- Equipment
- Expertise
19URETERAL CALCULI
TREATMENT OPTIONS
- Observation
- Shock wave lithotripsy
- Ureteroscopy
- Blind basket extraction
- Percutaneous approach
- Open surgery
20CONSERVATIVE MANAGEMENT
- Analgesics, hydration, and possibly
antispasmodics - Follow plain radiographs at 1-2 week intervals
21URETERAL CALCULI
SPONTANEOUS PASSAGE
22URETERAL CALCULI
SPONTANEOUS PASSAGE
- Of all stonesthat pass spontaneously, 95 will
pass within 6 weeks
Miller Kane, 1999
23URETERAL CALCULI
MEDICAL MANAGEMENT
Hollingsworth Hollenbeck, 2006
24URETERAL CALCULI
MEDICAL MANAGEMENT
Hollingsworth Hollenbeck, 2006
25INTERVENTIONAL MANAGEMENT Current Therapy
- Extracorporeal shock wave lithotripsy (for
proximal ureteral stones and least invasive
therapy) - Ureteroscopy (for mid and distal ureteral stones)
26URETERAL CALCULI
PARAMETERS FOR COMPARISON
- Stone-free is not everything !!
27URETERAL CALCULI
PARAMETERS FOR COMPARISON
- Effectiveness
- Morbidity
- Convalescence
- Cost
28DISTAL URETERAL CALCULI
COMPARISON OFMONOTHERAPY STUDIES
- URS is 10 - 18 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
29DISTAL URETERAL CALCULI
OVERVIEW OF HISTORICALCONTROL STUDIES
- SWL URS
- Effectiveness Slightly better
- Morbidity Less
- Hospitalization Less
- Cost Slightly less
30DISTAL URETERAL CALCULI
PROSPECTIVE, RANDOMIZED TRIAL
- 80 patients randomized to receive SWL or URS 40
patients had stones gt 5 mm 40 patients had
stones lt 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
31DISTAL URETERAL CALCULI
PROSPECTIVE, RANDOMIZED TRIALSTONES lt 5 MM
- URS SWL
- OR time (min) 19 63
- Fluoro time (min) 0.8 5.1
- Stone-free (days) 0.2 10.8
- Stent (days) 7.2 0
- Re-treatment rate 0 15
Peschel Bartsch, 1999
32URETEROSCOPY
33(No Transcript)
34Ureteroscopy
- Easier for lower stones
- Extraction of stone fragments
- Fragmentation
- Laser Homium Yg
- Mechanical EKL
- Explosive EHL
- Ultrasound
- Risks
35URETERAL CALCULI
FLEXIBLE URETEROSCOPY
36URETERAL STONE MANAGEMENT
URETEROSCOPY
- AdvantagesHighest success rateDefinitive Rx -
No waiting for stone passage - DisadvantagesMore invasive than SWLHigher
complication rateRequires greater technical
expertise
37Rigid ureteroscope specifications include the
following
-
- Tip diameter - 4.5-9.5F (6.9F most common)
- Optics - Fiberoptic bundles
- Working channels - One, 2, or 3 (2 channels
preferred) - Accessory length - Average, 40 cm
38Flexible ureteroscope specifications include the
following
- Tip diameter - 6.9-9.8F (7.5F most common)
- Optics - Fiberoptic bundles
- Working channel - Single, 3.6F
- Access - Guidewire (0.035 in nitinol or 0.038 in
stainless steel) - Accessory length - Average, 100 cm
39INTERVENTIONAL MANAGEMENT More Invasive
Treatments
- Intracorporeal shock wave lithotripsy (through
ureteroscope) - Percutaneous nephrostomy (for stones gt2 cm and in
proximal collecting system) - Laparoscopy (if complicated)
- Open surgery (rarely done)
40