Stenting versus Nonstenting after Uncomplicated Ureteroscopy for Lower Ureteric Stone Management.

Al-Hammouri F,Al-Kabneh A

Queen Rania Centre for Urology and Organ Transplant,
King Hussein Medical Centre, Amman, Jordan.

Address for Correspondence:
Dr Firas Al-Hammouri
P.O. Box 411
Tlaa' Al-Ali 11953
Amman- Jordan.
Email: firas_hammouri@yahoo.com



Abstract:
Objective: To assess the need for ureteral stent after uncomplicated ureteroscopy for lower ureteric stones using intracorporeal lithotripsy.
Materials and Methods: A total of 112 patients underwent ureteroscopic lithotripsy for lower ureteric stones at King Hussein Medical Centre (KHMC) between April 2003 and Augast 2004. After stone fragmentation, 104 patients were enrolled in our study and they were randomly divided into two groups: the first group (stented, 52 patients) had ureteric stents inserted postoperatively, while the second group (nonstented, 52 patients) had no stenting. The stent was removed at two weeks interval. Patients in each group were assessed for success, operative time, postoperative pain, irritative voiding symptoms, hematuria, and stricture formation.
Results: The two groups were comparable with respect to patient age, gender and mean stone size. Mean operative time in the stented group was 32 minutes (range 22-70), compared to 28 minutes (range 20-62) in the nonstented group. Irritative voiding symptoms were seen in 65% of the stented group, compared to only 9.6% in the nonstented group. 18 patients (34.6%) in the stented group patients and 10 patients (19%) in the nonstented group required two or more oral analgesic tablets a day in the immediate postoperative period. Re-admission to the hospital for pain control was necessary in one patient in the nonstented group. 18 patients (34.6%) and 6 patients (11.5%) developed hamaturia in the stented and the nonstented groups respectively. The stone-free rate and stricture formation showed no difference between the two groups.
Conclusion: Ureteral stent is not necessary after uncomplicated ureteroscopy for lower ureteric stone management using intracorporeal electrohydrolic lithotripsy. The ureteral stent increases the incidence of irritative voiding symptoms, pain and hematuria in addition to increased operative time and cost.

Keywords: Ureteral stent, ureteroscopy, ureteric calculi.
 

Introduction:
Ureteroscopy and intracorporeal lithotripsy have become a highly effective, minimally invasive treatment for ureteric calculi [1]. Routine placement of ureteral stents has been the standerd care following ureteroscopic stone management in most centers [1,2]. This is usually done to minimize postoperative ureteral obstruction and subsequently reduce the incidence of recurrent renal colic due to ureteric edema. In addition, it is thought that stent insertion promotes healing and decreases the incidence of post ureteroscopic ureteral stricture, and that it aids in the passage of stone fragments secondary to passive dilatation [3,4].
However, stent placement is associated with considerable morbidity as stent-related complications are reported in 10-85% of cases. These complications include irritative voiding symptoms, hemturia, encrustation, migration and stent fracture [2,5].
In view of recent marked improvements in ureteroscope design and advancement in intracorporeal lithotripsy, numerous studies have questioned the routine use of stenting post ureteroscopic stone management. Denstedt et al performed a prospective trial of non-stented versus stented ureteroscopic lithotripsy, and concluded that significant fewer symptoms were seen without stent in the early post-operative peroid, while there was no difference in terms of complication and stone free status [2].
The aim of our study was to assess the need for routine ureteral stent after uncomplicated ureteroscopic stone disintigration in the lower ureter.

Materials and Methods:
This study is a prospective randomized trial done at our center from April 2003 to August 2004. During this period, 112 patients had lower ureteric stones (average stone size less than 2cm) below the sacroiliac joint managed by ureteroscopy with intracorporeal lithotripsy.

Patients with history of sepsis, renal failure, bilateral ureteric stones, previous failed ureteroscopy, solitary kidney or pregnancy were excluded from our study. Patients detected intra-operatively to have significant mucosal injury or ureteral perforation were also excluded.
Of the 112 patients who underwent ureteroscopy with intracorporeal lithotripsy for lower ureteric stones, 8 were excluded because they did not meet the selection criteria of the study. Towards the end of the procedure, the remaining 104 patients were randomly divided: 52 had stenting (stented group) and the other 52 did not (nonstented group).

Surgery was performed on an outpatient basis, under general anesthesia in the dorsal lithotomy position with rigid 7.5f ureteroscope in combination with electrohydrolic lithoclast. A safety guidewire was inserted into the ureter by cystoscope under fluoroscopic control to maintain access. The ureteroscope was introduced without dilatation unless the ureter was too narrow. Continuous irrigation was done to maintain a clear ureteroscopic view. The stone was fragmented with electrohydrolic lithotripsy if required to less than 3mm with retrieval of pieces using stone removal forceps.
At the end of the procedure, patients were randomized to a stented or non-stented group. In the stented group, a double J (4.8f, 25cm) stent was placed under fluoroscopic guidance through the ureteroscopic operative channel or over a guidewire via the cystoscope, and the position of the stent was confirmed fluoroscopically at the end of the procedure to be in the urinary tract. All patients received prophylactic intravenous first generation cephalosporine at the time of induction, and continued 5 days on an oral quinolone. At the end of the procedure, patients were transfered to the recovary room for observation, and were discharged once they had stable vital signs, satisfactory pain control, and tolerance for oral diet.
All patients were evaluated by KUB at two weeks, and those with double J stent were scheduled for cystoscopic removal on the next operative list under local anasthesia. Follow up IVU was performed at 3 months post ureteroscopy to evaluate the urinary tract and identify ureteric stricture formation.
The outcomes measured were post-operative pain, irritative urinary symptoms, hematuria, number of visits to emergency room, late complications and stone free status.

Results:
The two study groups were comparable with respect to patient age, sex, and stone size, table 1. All patients were treated on an outpatient basis.
Operative time was calculated from the time of cystoscopy to the final removal of the endoscope, the mean operative time in the nonstented group was 28 minutes (range 20-62) compared to 32 minutes (range 22-70) in the stented group, with no significant difference in time to fragmentation and retreival of stones, table 1.
Post-operative pain was evaluated by the requirments for oral analgesia and the need for hospitalization for pain control. In the nonstented group, 10 patients (19%) required more than one tablet of oral analgesic a day, three patients (5%) visited the emergency room due to renal colic that was not responding to oral analgesics and one of them (1.9%) required hospitalization for pain control. On the other hand, 18 patients (34.6%) in the stented group required more than one tablet of analgesic a day, three patients (5%) visited the emergency room due to renal colic that was not responding to oral analgesics. However, none of the patients in the stented group required hospitalization, table 2.
Irritative voiding symptoms and macroscopic hematuria were seen more in the stented group, as 34 patients (65%) from this group experienced dysuria and frequency, as compared to only 5 patients (9.6%) from the nonstented group. 48 hours post-operatively, macroscopic hematuria was noticed by 18 patients (34.6%) in the stented group, compared with only 6 patients (11.5%) in the nonstented group, table 3.
Regarding post-operative complications, one patient from the stented group developed fever due to pyelonephritis 24 hours after ureteroscopy, without signs of septicemia and was admitted for intravenous antibiotics for three days and was discharged on oral antibiotics without sequale. One other patient (1.9%) was admitted with blood clot retention that was treated by urethral catheterization for 48 hours, and was then discharged with normal voiding. One female patient had migration of the stent down into the urethra and presented to our emergency room 48 hours after ureteroscopy with sudden onset of uncontrolled continous dribbling of urine that disappeared immediately after removal of the stent in the emergency room. table [3].
At two weeks postoperatively, the stone-free rate was 100% in both groups. No hydronephrosis or ureteral stricture formation were detected by intravenous pyelogram 3 months postoperatively.

Discussion:
Stenting after ureteroscopy has been recommended to prevent the development of ureteral stricture, aid in the passage of stone fragments and to promote ureteral healing after ureteroscopy [4]. On the other hand, ureteral stenting may be associated with significant morbidity such as irritative voiding symptoms, pain, and hematuria. In addition, it may lead to various complications such as encrustation, stent fracture, ureteral erosion, migration, knotting and development of ureteroarterial fistula [4,6].
With the recent development of small calibre ureteroscopes and with the advances in intracorporeal lithotripsy devices, stent positioning as a routine part of the post-operative care after ureteroscopy has become under questioning. In 1999, Hosking et al have concluded that routine placement of ureteral stent following uncomplicated ureteroscopic removal of distal ureteral stone was not necessary [3]. A few prospective randomized trials have recently been reported in the litrature, and all showed no difference in stone free status between stented and nonstented groups. However, post-operative pain and irritative voiding symptoms were reduced with omission of the ureteral stent [2,7-11]. In our study, irritative voiding symptoms in the stented group was seen in 65% of patients, as compared to only 9.6% of patients in the nonstented group.
Routine placement of ureteral stent after ureteroscopy adds to the overall cost of the procedure in addition to the cost of cystoscopic removal of the stent. Netto et al assessed the cost effectiveness of this and concluded that nonstented ureteroscopy is cheaper by 30% 12. Furthermore, removal of the stent using local anesthesia is more traumatic than the initial ureteroscopy procedure using general anesthesia [13].
Postoperative pain in our study was evaluated by how much analgesia was needed by patients each day, in addition to the number of re-admissions to hospital for pain control. In the stented group, 34.6% of patients required two or more analgesic tablets a day for pain control but none of them required hospitalization for intractable pain. The increased intrapelvic renal pressure, especially while voiding, explains this increased incidence of pain. Ramsay et al demonstrated in porcine model that ureteral intubation cause an increase in intrapelvic renal pressure [14].
The development of ureteral stricture is a well-established long-term complication following ureteroscopy. However, the incidence of ureteral stricture is dramatically decreased in recent years due to the advancements made in endourologic technology [15,16,17]. Some authors have suggested that stenting after ureteroscopic lithotripsy may decrease the incidence of postoperative stricture formation. Denstedt et al, in his prospective study on 58 patients following ureteroscopic lithotripsy for a lower ureteric stone, found no stricture on patients' followup [2]. Similar to our study, Chen et al revealed absence of stricture formation in stented and nonstented patients 7. Roberts and colleagues reported that the primary risk factors for the development of ureteral stricture were stone impaction more than two months and ureteral perforation at site of stone impaction during ureteroscopic lithotripsy [18].

Conclusion:
There were no difference between stented and nonstented group following ureteroscopic lithotripsy in term of stone passage and development of ureteric stricture. However, we noticed less irritative urinary symptoms and less pain in the nonstented group. In addition, stenting was associated with an increase in cost. Therefore, we recommend that stent replacement should not be performed routinely following uncomplicated ureteroscopic lithotripsy for small lower ureteric stones.

References:
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3. Hosking DH, McColm SE, Smith WE. Is stenting following ureteroscopy for removal of distal ureteral calculi necessary ? J Urol 1999;161:48-50.
4. Knudsen BE, Beiko DT, Denstedt JD. Stenting after ureteroscopy: pros and cons. Urol Clin N Am 2004;31:173-18.
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6. Srivastava A, Gupta R, Kumar A, et al. Routine stenting after ureteroscopy after distal ureteral calculi is unnecessary: results of a randomized controlled trial. J Endourol 2003;17:871-4.
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Table 1. Characteristics of patients in the two study groups.

 

Table 2. Post-operative pain, analgesic requirments, emergency room visit and hospitalization for pain control.
 

Table 3. Post-operative symptoms and complications.