definition for ” forgotten ” does not exist; however, many previous studies
consider a variable period of greater than 3 to 6 months to constitute a
forgotten stent 2. The causes of forgotten ureteral stents could be
classified as surgeon’s, patient’s, stent material and others factors; In a
biochemical and optical analyses of stent encrustations by Robert et al.,
they revealed that encrustations consisted mainly of calcium oxalate, calcium
phosphate and ammonium magnesium phosphate 3,4.
containing stents tend to be more resistant to encrustation, followed by
polyurethane, silitek, percuflex and hydrogel coated polyurethane1.
We use polyurethrane stents at our center.
compliance from the patient side is the major concern, which leads to forgotten
DJ stent in situ 5, and it is reflected in out study as well
al reported on 15 irremovable ureteral stents in Japanese patients. The
mean indwelling times of these stents was 20 months 6. In a study by
Ringel A et al, in total of 110 stented kidneys, they observed that the total
complication rate was up to 32.7% and in 8.2% of the cases, the stents had migrated
7. In another study, Damiano R et al observed flank pain in 25.3%,
encrustations in 21.6%, irritative bladder symptoms in 18.8%, hematuria in
18.1%, fever more than 104°F in 12.3% and stent migration in 9.5% of the patients
8. In our study, most common presenting complaints were LUTS
followed by hematuria and flank pain. They also reported that longer duration
of stent retention was associated with increased frequency of encrustations,
infections, calculus formation and obstruction of the stented tract.
literature shows that DJ stent had been missed for a maximum of 23 years 2;
in our study the maximum duration was of 6 years.
no pre-defined algorithm for the management of the forgotten DJ stents but it
depends on the site of encrustation, the size of the stone burden and the
function of the affected kidney Management may often require multiple
endourologic approaches and/or open surgeries. Kane et al. in Senegal
reported in a comparative study of 89 patients with upper urinary tract calculi
who underwent endourology intervention or open surgery. Less complication and
early discharge from hospital was observed in the endourology group 9.
al has described SWL as the noninvasive procedure of choice for calcified
ureteral stents. SWL successfully fragmented calcifications on the renal end
and ureteral segment of the stent, but electrohydraulic lithotripsy was
necessary to fragment calcification on the bladder end10. For
encrustations located at the upper coil and or stent body, ESWL and flexible
ureteroscopy retrieval of the stent has been reported to be non-invasive and
effective first line therapy. ESWL is however indicated mainly for localized,
low volume encrustations 11,12. Flexible ureteroscopy with holmium
laser lithotripsy is an alternative minimally invasive treatment option. Okeke et
al. 13 and Papoola et al.
14 eventually underwent
successful endoscopic retrieval of the stent material with no complications.
In case of severe incrustations, management modalities are more
complex. Many investigators have employed ESWL, URS-Se, laser-lithotripsy,
PCNL, chemolysis using various chemolytic agents administered via a
percutaneous nephrostomy tube, and open surgery either alone or in combination
with other procedures 15,16.
Single procedure removal of encrusted stent has also been reported
5, but it should be avoided for severely encrusted stents. In case
of long intraoperative time, over enthusiastic single-stage removal is
discouraged, and it is better to stage the procedure 2. Ecke and colleagues
proposed that distal part of the stone burden be removed first as it will
facilitate the placement of the ureteric access catheter and then PCNL could be
used for the stone- covered proximal end of the stent 17.
Tang VC et
al studied the stent card system to track the retained DJ stent and have
proposed the computerized DJ stent registry and similarly Lynch M F et al in
their study showed the importance of electronic stent register and stent
extraction reminder facility to avoid the DJ stent follow up loss and avoid the
morbidity associated with it 18,19. McCahy et al. recommended
that a computer record should be composed recording the patients that stent was
placed in urology clinics and warning the urology physicians about the time of
removal of stents 20. “Stents on strings” have been proposed where
one end of the stent is tied to a sting, which is externalized for easy removal
later. Prevention is the best form of treatment to avoid this complication.
interactive sessions, were found that the most common reason for the forgotten
stent was lack of knowledge to the patient and the attendants for the same and
it was seen in 13 patients. Of the rest 3 patients, two patients had forgotten
themselves and one was lost to follow up till the patient had recurrent