Abstract
Objectives: To present our experience with ureteroscopy for the
treatment of ureteral calculi.
Methods: A retrospective review of
904 ureteroscopies for ureteric lithiasis performed in 810 patients (mean age 39.3
years; range 14–70 years; 485 males, 325 females) at Prince Hussein
Bin Abdullah
Urology Center
between January 2006 and January 2008 was conducted. A 9.5F rigid ureteroscope was used in all
patients. Pneumatic lithoclast was
used to fragment stones and the fragments were retrieved with forceps and/or baskets.
Hospital and follow-up records of the patients were reviewed in this study. Success and complication rates are presented.
Results: Sixty one (7.5%) of the stones were located in the
upper, 204 (25.2%) in the middle and 545 (67.3%) in the lower ureter. The size
of the stones treated ranged between five to 20 mm. Ureteroscopy resulted in successful
stone removal in 750 patients (92.6%). Six hundred and fifty six stones were
treated in a single session. Repeat ureteroscopy was performed in 94 patients (11.6%).
In 53 patients (6.5%) the stones were pushed up and successfully underwent ESWL.
Antegrade renoureteroscopy was performed in three cases of ureteroscopy failure
for fixed upper ureteric stones. A total of four patients with ureteroscopy
failure were referred for open surgery. Gross hematuria was observed in eight
(1.0%) patients, 15 (1.9%) patients suffered from postoperative fever for an
average of two days (range 1-4 days), 17(2.1%) patients had persistent renal
colic. Nine cases (1.1%) of ureteral perforation were successfully treated by
JJ stent, and only one case of ureteral avulsion (upper ureter) was treated by
open surgery. Four cases of postoperative ureteral stricture have been
observed.
Conclusion: On
the basis of our experience, ureteroscopy is an effective interventional modality
for ureteric stones with a low complication rate.
Key words: Complications, Ureteroscopy, Ureteral calculi
JRMS
June 2010; 17(2): 12-18
Introduction
Historically, ureteroscopy for ureteric stones was
first done by Marshall in 1964 using flexible ureteroscope.(1)
Subsequently, in 1971, Takagi and colleagues reported the use of a passively
deflectable flexible ureteroscope with a distal end of 6-F.(2)
In recent years, more sophisticated flexible and rigid ureteroscopes were
introduced, making the upper tract accessible to the endourologist.(3)
Today, ureteroscopy is one of the daily urologists'
practices, and regardless of the location of the ureteric stone, access and
definitive treatment is commonly achieved with a minimal risk of complications.(4)
In this study, we present our experience with ureteroscopy for the treatment of
ureteral calculi.
Methods
Between January 2006 and January 2008, 904 ureteroscopic
procedures for calculi of the ureter at various levels were offered to 810 consecutive
patients (mean age 39.3 years; range, 14–70 years; 485 males, 325 females) at Prince Hussein
Bin Abdullah
Urology Center.
All patients underwent preoperative radiographic imaging studies, including
plain abdominal radiograph, renal sonogram and computerized tomography, from
which stone size and location and degree of obstruction were assessed. All
patients had surgical indications to treat the stones by retrograde
ureteroscopy. Patients with either bilateral calculi or steinstrasse were
excluded. All the ureteroscopies were performed with a 9.5 F rigid ureteroscope
(Storz, Germany), under general anesthesia.
Pneumatic (Swiss made) lithoclast was
used for lithotripsy, and forceps and/or baskets were used for the removal of
stones.
The retrograde
ureteroscopy procedure used was as follows. After general anesthesia induction
and prophylactic antibiotic administration (intravenous gentamycin), patients
were placed in lithotomy position. A full cysto-urethroscopy was performed
initially. An angiographic catheter was used to intubate the ureteric orifice. Under fluoroscopic guidance, a retrograde
ureteropyelogram was performed with diluted contrast medium in all cases to
study the ureteral anatomy (unless a ureteral stent was already in place before
the procedure) and a guide wire (Teflon or hydrophilic) was passed into the
collecting system prior to the introduction of the ureteroscope. The
ureteroscope was introduced just under the stone following dilatation of
ureteric orifice if needed. The stone was fragmented with a pneumatic lithotripter
if required to less than 3mm with retrieval of pieces using stone removal
forceps and/or basket. Endoscopic inspection was done at the end of the
procedure to rule out any residual calculi or trauma. The placement of a
ureteral stent at the conclusion of the procedure was left to the discretion of
the treating urologist.
Ureteroscopy
was performed on an outpatient basis for those who had an uncomplicated
procedure. At the end of the procedure, patients were transferred to the recovery
room for observation, and were discharged once they had stable vital signs and satisfactory
pain control.
The endpoint
of the study was for the patient to be stone free or to have an insignificant
residual stone (3mm or less). Patients were followed postoperatively a minimum
of three months (median 12). A plain radiograph of the abdomen (in patients
with radio-opaque calculi) was performed at two weeks to document stone
fragmentation and large residual or migrated fragments and renal
ultrasonography was performed two to three months postoperatively. Other types of upper tract imaging were not
done except when there were complications.
We reviewed
the medical records to determine the immediate and long-term success of the
procedure. The incidence and nature of complications were also noted.
Results
Eight hundred
and ten (810) ureteric stones have been treated by rigid ureteroscope. Most of
the stones were in the lower ureter (67.3%). Table I shows the characteristics
of the calculi.
The overall
success rate of retrograde ureteroscopic removal of calculi was 92.6 % (see Table
II). Ureteroscopy achieved complete stone clearance in one session in 656 patients
(81%). In 94 patients ureteroscopy had failed initially to fragment the stones
completely and a repeat ureteroscopy was undertaken after two weeks to render
the ureter stone free improving the success rate to 92.6%. The operative time
ranged from 10 to 45 minutes,
with an average time span of 25. A comparison of the stone-free rate of our
study to other contemporary ureteroscopic stone series is given in Table III.
Stents had
previously been placed in 66.7% (n=540) and dilatation of the ureteric orifice
was necessary in 16.7% (n=135) of the cases. The targeted stones were extracted
in one piece via basket or grasper in 123 cases (15.2%) with the remaining
requiring fragmentation, 706 patients were discharged without a double J
catheter in situ. A retrograde ureteral catheter
was placed in 33 and double J catheter (DJC) replacement was needed in 104
patients due to impacted stone and/or failed procedure.
Percutaneous
Nephrostomy (PCN) placement was required in six cases of URS failure.
In 53 patients (6.5%) the stones were pushed up and successfully
underwent ESWL; in 47 patients intact stones or large residual fragments were
accidentally pushed up, while in the other six patients upper ureteric stones
could not be reached and were intentionally pushed back into the kidney.
Antegrade renoureteroscopy was performed in the three cases of ureteroscopy
failure for fixed upper ureteric stones.
Complete stone clearance was achieved in all patients with antegrade
ureteroscopy without any intraoperative or postoperative complications. A total
of four patients with ureteroscopy failure were referred for open
surgery; two patients
underwent ureterolithotomy for an extremely narrow stenosis just distal to the stone site, one case had a large impacted calculus and preferred to avoid more endoscopic procedures and one case developed ureteral avulsion (upper ureter) which was treated by open surgery.
|
Table I. Characteristics of the ureteral calculi
|
Character
|
Number
|
%
|
|
Site Upper
Mid
Lower
|
61
204
545
|
7.5
25.2
67.3
|
|
Side Right
Left
|
411
399
|
50.7
49.3
|
|
Size =<1cm
>1cm
|
685
125
|
85
15
|
|
Table
II. The success rate according to site of the stones
|
Site
|
Number
|
%
|
|
Upper
|
48/61
|
78.7
|
|
Mid
|
182/204
|
89.2
|
|
Lower
|
520/545
|
95.4
|
|
Total
|
750/810
|
92.6
|
|
Table III. A comparison of the current
study stone-free rate with other ureteroscopic stone series
|
Studies
|
No. of stone-free patients/ Total No.
of patients
|
%
|
|
Current study
|
750/810
|
92.6
|
|
Dasgupta P et al.
|
73/101
|
72.3
|
|
Butler MR et al.
|
1735 /1936
|
89.6
|
|
Shah OD et al.
|
3540/3978
|
89
|
|
Krambeck AE et al.
|
529/579
|
91.4
|
|
Fong YK et al.
|
46/51
|
90
|
|
Weide Z et al.
|
168/180
|
93.3
|
|
Ather MH et al.
|
350/437
|
80
|
|
Samaniego PM et al.
|
335/360
|
93.1
|
|
Bierkens AF et al.
|
98/105
|
93.3
|
|
du Fossé W
et al.
|
263/292
|
90.1
|
|
Park HK et al.
|
185/200
|
93
|
|
Valente R et al.
|
280/298
|
94
|
|
Puppo P et al.
|
354/378
|
93.6
|
|
Küpeli B et al.
|
60/66
|
90.9
|
|
Cheung MC et al.
|
278/306
|
91
|
|
Silinskas V et al.
|
54/59
|
92.3
|
|
Rao MP et al.
|
114/124
|
91.9
|
|
Ilker Y et al.
|
195/205
|
95.1
|
|
Chow GK et al.
|
172/182
|
94.4
|
|
Raza A et al.
|
53/53
|
100
|
Table IV. Complications of ureteroscopic stone treatment
|
Complications
|
Number
|
%
|
|
Minor
Hematuria
Fever
Renal colic
|
8/810
15/810
17/810
|
1.0
1.9
2.1
|
|
Major
Perforation
Stricture
Avulsion
|
9/810
4/810
1/810
|
1.1
0.5
0.1
|
|
Total
|
54/810
|
6.7
|
The overall
complication rate was 6.7% (Table IV). Major complications, which included perforation,
stricture, and avulsion, occurred in only 14 (1.7%) of the 810 patients
undergoing ureteroscopy. Minor complications (hyperthermia, gross hematuria,
and persistent renal colic) were encountered in 4.9% of the cases, all of which
were resolved with medical treatment.
The commonest
major complication was perforation. It was usually trivial and near the
vesicoureteric junction. This occurred in nine cases: six in the lower ureter,
one in mid ureter, and two in the upper ureter. All cases were successfully
treated by DJC; immediate ureteric DJ stenting was performed in eight cases and
the other one underwent percutaneous drainage and delayed antegrade ureteric
stenting.
At a mean follow
up of 12 months ureteral strictures developed in four patients. Of nine
patients who had perforation, two developed strictures. In two patients
ureteral strictures developed at the previous stone site following endoscopic
lithotripsy of impacted ureteric stone.
All were detected during the first year after ureteroscopic stone
extraction. One of the patients was treated with open surgery
(ureteroneocystostomy) after failure of endoscopic dilatation. For the other
three patients endoscopic dilatation was done and catheterized by DJC which was
subsequently removed without recurrence of the stricture. Only one case of
ureteral avulsion occurred and treated by end-to-end repair of the ureter in
its upper third.
There were 50
unplanned admissions for minor complications: 17 patients required immediate
admission for pain control and were discharged on the following day, 33 patients
required delayed admission one to 13 days after the procedure, 25 for infection
and eight for stent-related symptoms. Hospital
stay ranged from one to four days (mean 1.3 days). All patients were treated
conservatively. There were no anesthesia-related morbidities or postoperative
deaths.
Discussion
Extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy are
currently the most common treatment options for ureteric stones in clinical practice.(5,
6) From the patient's
viewpoint, achieving an immediate stone-free status with a single modality is
the ultimate goal for any therapeutic approach chosen. Therefore, due to the
high rate of retreatment sessions in ESWL, ureteroscopy has become the method
of choice for the quickest way of rendering patients stone-free.(7, 8)
In the present study, a high stone free rate was achieved (92.6%) with a
retreatment rate of 11.6%. Review of published series on treatment with
ureteroscopy using a variety of ureteroscopes and intracorporeal lithotripsy
devices reveals success rates ranging from 72.3% to 100% with retreatment rate
of 2.1 to 13%.(9-25)
We
used rigid ureteroscopes because we believe that they continue to be the
mainstays of ureteral stone therapy. Similar
to our results, stone-free rates of above
90% in all parts of
the ureter using Storz 7.5-10.5 F rigid
ureteroscope have been reported.(13-15) The review of the
latest literature showed comparable stone free rates with the use of semi rigid
or flexible ureteroscopes.(26) The type of lithotripter used
can have a major effect on success rates.(27) Pneumatic lithotripsy has been found to be the
most effective, safe and economical mode of treatment.(28) We
applied pneumatic lithoclast which is not disposable, strong enough for
fragmenting all types of stones and is cheaper than Holmium laser. Our results
show that it is very effective in breaking calculi; we always fragmented the
entirely stone into minimal fragments. With
electrohydraulic and ultrasonic energy, there is more risk of complication, as
for example ureteral perforation.(12,29) Some authors
utilized ballistic energy with excellent results.(30) However, with the pneumatic lithotripter,
there is more retrograde migration of the ureteral stone during its fragmentation;
it can push more than 10% of the stones into the kidney during the procedure.(28,31)
Issues related
to ureteral dilation, stenting, and the use of ureteral access sheaths are not
well defined. Some authors(17,32) advocate routine balloon
dilatation of the intramural ureter and introduce ureteral stent in all the
patients. They think that balloon dilatation allows for easier and more rapid
access through the intramural ureter, facilitating repeated passes of the
ureteroscope and removal of calculi. In our study, dilation was not routinely
used, unless the ureter was too narrow or there was severe edema preventing
endoscopic access to the stone. Rigid ureteroscopic access was successfully
achieved in most of our patients without need for ureteral orifice dilation.
Therefore we concluded that dilation does not improve the results and does not
even protect against ureteroscopic complications. Many retrospective series in
the literature support our conclusion.(1,2,6,33-35)
Ureteral
stenting after ureteroscopy for ureteric calculi is common practice, as demonstrated
by its 83% to 100% incidence in large series.(6,7,30,33) Our
ureteric stenting rate of 17% might be considered low by current standards in some
centers. Our practice is to leave ureteric stent in the presence of dilatation
of ureteric orifice, complications, impacted stone and/or failed procedure. We do
not advocate routine stenting because of the intolerable urinary symptoms
caused by the stent and placing a stent required more operative time, cost and
re-instrumentation for stent removal.
Many authors reported undesirable symptoms in patients with a stent and
noted a high rate of symptom resolution of 94% to 100% after removal.(3,33)
Retrospective, prospective randomized studies have found uncomplicated
ureteroscopy to be safe with no ureteric stent.(1,9,36)
Although some urologists advocate routine use of ureteric access sheath in
proximal ureteroscopy,(27,37) we did not use it because we think
that prolonged transmural pressures caused by sheaths potentially lead to
ischemia and ureteral stricture. There is a reported 1.7% stricture rate with
access sheath use.(38)
Percutaneous
removal was indicated in three patients with large stones in the upper ureter
as a salvage procedure where ESWL and ureteroscopy had failed and complete
clearance was achieved. Similar results were reported in the literature.(29,39)
In our
well-equipped urological centre, indications for open ureterolithotomy are limited. A review of our own cases revealed that open
surgery constituted 0.5% of all procedures.
The most common indication in our study was ureteric anatomical
abnormalities (2 cases). Several authors have reported that the rates of open
stone surgery since the establishment of shockwave lithotripsy and subsequent
endoscopic advancements are only 0.3 to 5.4%.(40-42)
The overall
complication rate in our study was 6.7%, mostly due to minor complications. In
most studies published between 1996 and 2003, the overall incidence of
ureteroscopic complications was below 7%.(27,43,44) The
reported incidence of minor complication was 0–35%(45)
compared to a rate of 4.5% in our study. The number of patients developing
fever or sepsis after ureteroscopy can be reduced further by appropriate
pre-operative antibiotic usage. Prophylactic antibiotics were, therefore,
used routinely in all cases to cover the procedure and the early post-operative
period.
In this
study, the incidence of ureteric injuries (perforation, stricture, and
avulsion) was 1.7%. Since urologists
with multiple stages of experience were included in this study, most of these
complications occurred due to unskillful practices. There were eight
insignificant perforations mainly near the vesicoureteric junction during wire
manipulation. One major perforation (0.1%) followed pneumatic lithotripsy of
impacted stone in the upper ureter. In other published studies, the rates of major
perforation were 1-3% using semirigid ureteroscopes, 1-11.2% with rigid ureteroscopes,
and 3-5% when electrohydraulic lithotripsy was used during ureteroscopy.(46)
Stoller and colleagues(47) encountered 19% of complications
in stone extractions with 10.5 to 12.5 F ureteroscopes, including 15.4% perforations
as compared with only 0.1% in our study. The low major perforation rate using rigid
ureteroscope in our study was attributed to smaller ureteroscope and surgeon
experience. Some authors suggest a
significant reduction in ureteric perforation with surgeon experience and small
ureteroscopes(4) while others showed a significant
association of ureteral perforation with increased operative time.(48,49)
Many studies have demonstrated a low ureter perforation rate using laser
energy, especially when the Holmium laser is used as the energy source.(50,51)
Other factors thought to reduce complications, such as the ureteral access
sheath, ureteral stents, and routine ureteral dilation, are controversial, with
varying opinions in the literature.(7)
During the
follow-up there was a ureteric stricture in two patients who had perforation
and in other two patients ureteral strictures developed at the previous stone
site following endoscopic lithotripsy of impacted ureteric stone. The mechanism
of stricture formation has not yet been completely elucidated and it is likely
to be multi-factorial. However, direct mechanical trauma (perforation),
relative ischemia from the use of large diameter ureteral instruments and
thermal injury has been implicated as contributing factors in stricture
formation.(52) Some authors have suggested that stenting
after ureteroscopic lithotripsy may decrease the incidence of postoperative stricture
formation.(53) A high stricture rate of 14.2-24% was reported
previously after ureteroscopic treatment of patients with stones impacted in
the ureter for more than two months.(29,53) Some authors say
that removal of all the stone fragments is important to prevent additional
chronic mucosal inflammation leading to stricture formation.(6,7,29)
As in some series (Roberts and colleagues), perforation and impacted stones
treated by endoscopic lithotripsy were the primary risk factors for stricture
formation in our study. Only one of the patients was treated with open surgery
(ureteroneocystostomy) after failure of endoscopic dilatation of the stricture.
Ureteric
avulsion remains the most important complication of ureteroscopy.(54)
We had one case of ureteral avulsion (0.12%) after difficult manipulation of ureteral
stone with Dormia basket. This was due to the association of a diseased ureter
rather than an improper handling of the endoscopic instruments. Although no
ureteral avulsions were noted in some studies,(7,10) there
was no difference between our current study and many other studies with regard
to ureteral avulsion rates.(9,29,46,55) The zero avulsion rates reported in some
studies reflect the advances made in the field of laser and mechanical
lithotripsy, which can prevent ureteral avulsion associated with basket
extraction of stones.(5,7,10) Since we had a ureteral
avulsion in a patient, Dormia basketing is hardly used in our center, we much
prefer the use of grasping forceps to retrieve any fragment after ureteroscopy.
From a
retrospective review of planned same-day discharge after ureteroscopy in 810
patients, our admission rate was 6.3%. Therefore, ureteroscopy should be
considered an outpatient procedure. Extensive studies have proven the safety,
as well as the cost-saving potential of out-patient ureteroscopy.(36,56,57)
Conclusion
Ureteroscopy
is highly successful and minimally invasive, is associated with minimal
morbidity in the hands of skilled urologists, and has high immediate stone-free
rates resulting in decreased patient anxiety and resultant increased patient
satisfaction. Therefore, ureteroscopy should be considered the method of choice
in the management of most ureteric calculi.
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