ROMANCING THE STONE

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19 Οκτ 2013 (πριν από 3 χρόνια και 11 μήνες)

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ROMANCING THE STONE

THIRTY YEARS OF PROGRESS IN THE
DIAGNOSIS, PREVENTION AND
MANAGEMENT OF URINARY CALCULI

WHY STONES?


Lifetime prevalence 13%


Stone belt phenomenon


Global warming


American diet


Sedentary lifestyles

DIAGNOSIS


Symptoms


flank pain


Physical exam


Urinalysis


Radiographic


RADIOLOGY
-

1982


KUB


IVP

PROBLEMS WITH IVP


Some stones are radiolucent


Contrast allergy


Contrast nephropathy


Radiation exposure

RADIOLOGY
-

2012


Rarely contrast studies (CT, IVP)


Non
-
contrast CT scanning


ADVANTAGES


No contrast


Fast


Only indinavir stones and some matrix stones
are “radiolucent” for the CT


? Other pathology found

DISADVANTAGES


Radiation exposure


Expense

MEDICAL MANAGEMENT
-

1982


Taught no need to investigate first stone


Water


Thiazides

WHAT HAVE WE LEARNED?


If you have first stone, you are going to have
another


Medical management works


Oxalate restriction


Importance of uric acid in calcium stone
formation (protein restriction)


Importance of citrate as inhibitor


Importance of limiting salt intake

INTERVENTION
-

1982


If stone is < 5 mm, let it pass


Still good advice but can be morbid and
patient may be unproductive during that time
(shouldn’t drive if taking pain meds)


Can we predict better who will pass their
stone?

PREDICTION OF SPONTANEOUS URETERAL
CALCULUS PASSAGE WITH AN ARTIFICIAL
NEURAL NETWORK

James M. Cummings

Seth D. Izenberg

David Kitchens

Rupa Kothandapani

University of South Alabama

Mobile, Alabama


AUA 1999, JUrol 2000

Results


125 patients used to train neural network


55 patients in test set (25 with spontaneous
passage, 30 required intervention)


Network prediction was correct in 42
patients (76%)


Network prediction was 100% correct in the
subgroup passing their stones

Influences on network
predictions

Symptom duration*

Hydronephrosis grade

Position

Nausea/vomiting

Obstruction grade


*Most influential in neural network by far

INTERVENTION
-

1982


Blind stone basketing


Open surgery

INTERVENTION
-

2012


Ureteroscopy (URS)


Percutaneous nephrostolithotomy (PCNL)


Extracorporeal shock wave lithotripsy (ESWL)

Ureteroscopy


Performed transurethrally


Good for ureteral stones


Stone free rate 95% for distal ureteral stones


Flexible and rigid scopes


Variety of baskets, small lithotriptors and
lasers

PCNL


Scope passed into kidney through small
incision in flank


Stone visualized and broken up and extracted


Used mainly for very large staghorn type
stones


EXTRACORPOREAL
SHOCKWAVE LITHOTRIPSY

(ESWL)

ESWL


Discovered as a result of research into stress
on airplane wings passing through air


Thousands of shock waves passed through
body to strike stone


Stone breaks into small pieces and pass


Best used with renal and upper ureteral
stones < 2.5 cm in size


Complications / Morbidity


Hematuria (gross or microscopic): 100%


Pain: 60
-
70%


Renal colic in 5
-
10%


Hematoma / perirenal hemorrhage
(clinically significant): <1%


Sepsis <1%


Steinstra
sse

Complications / Morbidity


Renal trauma (hemorrhage, endothelial cell
damage, glomerular atrophy & sclerosis, &
interstitial fibrosis)


22% decrease in GFR after ESWL in solitary kidneys;
29% decrease after PCNL


Hypertension (inconclusive)


Bowel perforation: 3 reports.

Efficacy

Opell & Pahira. Contemp Urol; 12
-
27, October 2000

Efficacy


Stone
-
free rate using HM
-
3 for stones < 2 cm
is 91.3% at 3 months


Only 50
-
70% stone
-
free rate with 2
-
3 cm
stones


In general, stone
-
free rate is inversely related
to stone size

CONCLUSIONS


IN 30 YEARS


Diagnosis has moved from contrast studies to
noncontrast CT


Prevention is used over a broader range of
sufferers


Intervention is minimally invasive with scopes
and shockwaves


no longer open surgery or
blind efforts