What type of shockwaves is generated by spark-gap technology?
piezoelectric
electrohydraulic
electromagnetic
microexplosive
Correct Answer :
B. electrohydraulic
In an electrohydraulic generator, a high-voltage electrical current passes across a spark-gap electrode located within a waterfilled container; the discharged energy produces a vaporization bubble, that expands and collapses, generating a high-energy crushing wave.
Related Questions
What is false concerning urethral stones?
stones at posterior urethra could be pushed back to the bladder
stones at anterior urethra have to undergo a trial of milking out, using copious intra-urethral xylocaine gel
often respond to a two-week course of tamsulosin
respond to Holmium laser treatment
What is the least serious complications of PCNL?
uncontrollable bleeding
incomplete removal of stones
pneumothorax
colonic perforation
As per the fixed particle theory of stone formation:
the initial step is papillary plaque formation
crystals formation occurs inside the nephron
tubular precipitates form harmless crystalluria
the attraction of organic compounds and activation crystallization is regulated by osteopontin
What medications do NOT cause renal stones?
ciprofloxacin
indinavir
thiazides
triamterene
What could carry the least risk of colon injury during PCNL?
subcostal puncture performed during full expiration
previous open nephrolithotomy
access lateral to the posterior axillary line
horseshoe kidney
What risk factor(s) promote(s) stone formation?
dehydration
metabolic disorders
congenital anomalies
all of the above
What is (are) true concerning ESWL?
a stone is fragmented when the force of the shockwaves overcomes the tensile strength of the stone
fragmentation occurs as a result of compressive and tensile forces, erosion, shearing, spalling, and cavitation
the generation of compressive and tensile forces and cavitation are thought to be the most important
all of the above
What is the preferred entry point into the collecting system for PCNL for a 2.4 cm renal pelvis stone?
anterior lower pole calyx
posterior lower pole calyx
anterior upper pole calyx
posterior upper pole calyx
During pyelolithotomy for removing a staghorn urate stone; how to ensure a complete removal of calyceal branches?
by performing intra-operative ultrasonography
by performing radial nephrotomies
by performing adjunct PCLN
by taking a scout KUB film
What situation carries lower risk for lung injury during supracostal upper pole access for PCNL?
placing the patient in anti-Trendelenburg position
making the puncture under local anesthesia
injection Co2 gas to create a safety space under the diaphragm before puncturing
making the puncture during full expiration
What congenital anomaly is unlikely to result in stone formation?
left ureterocele
bifid right renal pelvis
neurogenic bladder
bilateral UPJ stenosis
What parameter impairs the kidney stone-free rate, after ESWL?
short skin-to-stone distance (SSD)
end-stage renal failure
a stone in the upper calyx
the presence of a 30 cm, 4.7 Fr ureteral stent in situ
What is the incidence risk of ureteral strictures following ureteroscopy?
3 6 %
12 15 %
0.4 0.8 %
0.09 0.14 %
What kind of stones is most amenable to ESWL?
cystine
brushite
Ca.oxalate monohydrate
Ca.oxalate dihydrate
What type of urinary diversion carries the highest risk of stone formation?
Kock pouch
Neobladder-to-urethra diversion
Florida pouch
Indiana pouch
What is false concerning prostatic stones?
composed of calcium phosphate and calcium carbonate
the vast majority are asymptomatic
most of the calculi are found in the transitional zone
they dont affect PSA levels
For how long a completely obstructed ureter could be respited with no expected permanent damage to renal functions?
2 days
2 weeks
2 months
4 6 hrs.
What is false concerning obesity and urinary stone formation?
obese patients have a higher tendency for uric acid stone formation
high-protein, low-carbohydrate diet might increase the risk of stone formation and bone loss
metabolic syndrome is associated with high urinary pH
Roux-en-Y-gastric bypass surgery may increase the risk for stone formation
What could the discomfort experienced during ESWL session be related to?
the energy density of the shock waves as they pass through the skin
the size of the focal point
a & b
none of the above
What does nephrocalcin do?
dissolves cystine stones
enhances nephrocalcinosis process over old scared areas
inhibits Ca.oxalate aggregation and crystallization
plays a secondary role in metastatic calcification process
What is the preferred irrigation fluid during PCNL?
physiological saline 0.9%
glycine 1.5%
balanced salt solution
distilled water
What medication(s) could be helpful in the management of cystinuria?
α-Mercaptopropionylglycine
d-Penicillamine
a & b
none of the above
What stones are radiopaque on plain X-ray film?
2,8 dihydroxyadenine stones
sulfa medications-induced stones
calcium oxalate stones
matrix stones
What type of stones is most effectively treated with PCNL?
Ca.oxalate monohydrate
cystine
matrix
Ca.oxalate dihydrate
Which of the following factors, positively, affect lower calyceal stone clearance after ESWL?
short and wide infundibulum
large lower-pole infundibulo-pelvic angle
the adjunct usage of PCNL
all of the above
What is false concerning patient`s preparation for PCNL?
active UTI is an absolute contraindication
fluoroquinolone is the first choice for antimicrobial prophylaxis
withholding aspirin for only 10 days is enough
despite sterile urine, stone fragmentation might release hidden bacterial endotoxins and viable bacteria
How does oral Mg.citrate inhibit Ca.oxalate stone formation?
by lowering urinary saturation of Ca.oxalate
by preventing heterogeneous nucleation of Ca.oxalate
by inhibiting spontaneous precipitation and agglomeration of Ca.oxalate
by all of the above
What type of shockwaves is generated by spark-gap technology?
piezoelectric
electrohydraulic
electromagnetic
microexplosive
What bowel surgery could result in enteric hyperoxaluria?
right hemicolectomy
small bowel resection
Roux-en-Y gastric bypass
b & c
What is false concerning recurrent stone formation?
best treated by total parathyroidectomy
first-time stone formers are at a 50% risk for recurrence
males have higher recurrence rate than females
stone formers produce stones of the same type every time