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
Removal of tumors from either the ureter or the
Repair of scars in the ureter
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
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
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.