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Double J
Stent
What is a double J stent?
A double J stent is a soft
tube that is placed during surgery. This tube has a curl
at both ends designed to prevent the stent from moving
down into the bladder or
up into the kidney. Some stents have a string attached to
them which exits from the urethra. Stents are placed in
the ureter which is the tube that runs from the kidney to
the bladder.
Why is a stent placed?
A stent is placed to prevent
or relieve a blockage in the ureter. After many stone
surgeries the small pieces of stone can drop down into the
ureter and block it, causing severe pain and occasionally
infection. A stent allows the ureter to dilate, which
makes it easier for stones or stone fragments to pass.
Other surgeries in which
stents are used includes :
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Removal of tumors from either
the ureter or the kidney
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Repair of scars in the ureter
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Removal of tumors from around
the ureter
Ureteral catheters and
stents
Ureteral catheters and stents
are fundamental to the practice of Urology. These devices
allow one to bypass and drain an obstructed ureter,
determine urine output from a particular renal unit, and
inject contrast to study the upper urinary tract With the
advent of newer methods to manage upper urinary tract
stones (ESWL and ureteroscopy), the indications and use of
Ureteral catheters have and will continue to further
increase.
History of its development
A review of the literature
shows that although there are references on the use of the
Ureteral catheter before 1967, the history of its
development began in that year, when Zimskind and
co-workers designed and used the first selfretaining
catheter that was inserted cystoscopically. However, it
was not until 1978 when the double-J shape was adopted
following the design of Finney.
Ideal Ureteral catheter
The ideal Ureteral catheter
should allow one to measure urine output from a particular
renal unit, drain even ten aciously purulent material,
allow injection of contrast for imaging and finally remain
indwelling and self contained if longterm ureteral
stenting or drainage is required.
The presently available
devices consist of external or internal ureteral
catheters. Both types are usually passed through the
Ureteral meatus via a cystoscope, though they can be
placed openly through different sites in the urinary tract
Externalized ureteral
catheters drain the upper urinary tract and pass through
the bladder, exiting the urethra and draining into an
external collecting device. They allow drainage through
ports and a central lumen and can be irrigated as needed
to drain tenacious and obstructing material By draining
externally, the output from the involved renal unit can be
carefully monitored. Contrast can be injected as needed to
evaluate the upper tract.
Unfortunately, these devices
are not self contained and must be secured to an
indwelling urethral catheter or they will migrate and be
extruded by Ureteral peristalsis. They therefore are not
suitable for long term outpatient care.
With this objective in mind,
internalized Ureteral catheters were developed. The most
commonly used type is a plastic catheter with a curl at
both the proximal and distal ends; i.e. Double J catheter.
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