Is Stent Placement Necessary After Uncomplicated Ureteroscopy for Removal of Impacted Ureteral Stones?

Abstract

Background and Purpose:

Ureteral stent placement after ureteroscopic lithotripsy has some advantages and disadvantages. In this randomized study, the necessity of ureteral stent placement after uncomplicated ureteroscopy for impacted ureteral stones was assessed.

Materials and Methods:

Between 2005 and 2007, 60 evaluable patients were equally randomized to groups with and without stents. Patients underwent ureteroscopic pneumatic lithotripsy for ureteral stones. The operation was completed with or without stent placement according to the randomization order. Excretory urography was performed 3 months after the procedure. All stents were cystoscopically removed at the third postoperative week. Sociodemographic and clinical variables (age, sex, stone location, stone size, operative time, hospital stay, narcotic and nonnarcotic analgesic use), and postoperative complications (fever, pain delaying discharge, emergency department visit, urinary retention, stent-related irritative symptoms) were evaluated.

Results:

Mean stone size was not significantly different in both groups. Mean operative time was significantly longer in the stent group: 30.5 ± 9.6 vs 43.7 ± 11.6 minutes. On the operation day and until postoperative day (POD) 5, narcotic (P = 0.004) and nonnarcotic analgesic (P = not significant) use was more frequent in the no-stent group. At POD 5 and later, although narcotic and nonnarcotic analgesic use were frequently necessary in the stent group, both were almost unnecessary in the no-stent patients. Stent-related irritative symptoms were overwhelmingly higher (10% vs 93%) in the stent group. Discharge was delayed (23% vs 10%) and unplanned emergency department visits (20% vs 10%) were exercised almost two times more commonly in the no-stent group. Stone-free rates were identical (n = 29/30; 97%) in both groups.

Conclusion:

Routine placement of a ureteral stent is not mandatory in patients without complications after ureteroscopic lithotripsy for impacted ureteral stones. Stent placement can be argued and agreed with the patients preoperatively in the light of the data presented above.

Introduction

U reteroscopy is frequently used with a high rate of success in the management of ureteral stones. Currently, ureteral stents are commonly placed after ureteroscopic lithotripsy in most of the treatment centers. The most important advantage of stent placement is prevention of ureteral obstruction; hence, occurrence of renal colic that may arise from ureteral edema or passage of stone fragments.^1
–3 Also, ureteral dilation caused by stents may ease the passage of small stone particles. It is proposed that other advantages of the application of stents are quicker healing of the ureter and prevention of ureteral strictures.^2,3

An impacted ureteral stone is variably considered either as a condition in which a stone remains at the same site for more than 2 months⁴ or the inability to pass a guidewire or catheter on initial attempts.⁵ Many ureteroscopic procedures can be classified as uncomplicated. These procedures can be defined as those with minimal or no ureteral trauma, minimal or no ureteral dilation, and minimal or no residual stone burden. Procedures related to impacted ureteral stones, however, cannot be counted among uncomplicated conditions. Impacted ureteral stones are the most difficult ones to manage, because there is usually severe ureteral inflammation. This results in an increased risk of ureteral injury by instruments during an endoscopic procedure.⁵

In this randomized study, the necessity for ureteral stent placement after ureteroscopic lithotripsy for impacted ureteral stones was assessed.

Patients and Methods

The study was conducted between January 2005 and October 2007. A total of 270 patients underwent ureteroscopic lithotripsy during this period, and patients with impacted ureteral stones were treated within the context of this study if they were not excluded from the study because of the reasons listed below. The criterion for the designation of impacted ureteral stone was the presence of stones that do not allow passage of a guidewire at initial attempts before the disintegration of stones at ureteroscopy. Patients were excluded from the study if they had nonimpacted stones, upper ureteral stones, radiolucent stone that made follow-up difficult, a solitary functioning kidney, significant concomitant ipsilateral renal stone load that necessitated further intervention after ureteroscopy, ureteral steinstrasse, preoperative ureteral stent placement or nephrostomy drainage, concomitant ureteral obstruction secondary to other causes such as stricture, failed ureteroscopic access to the stone, and intraoperative ureteral perforation.

Patients were consecutively randomized to two groups: One with a stent and next without a stent, alternating. Two patients had ureteral perforation (both had to have stent placement during the procedure that was not dictated by randomization order) during the procedure and two other patients were lost to follow-up. These four patients were excluded from the study, resulting in 60 evaluable patients that were included in this study—30 in the stent group and 30 in the no-stent group.

Patients were hospitalized at the day of the operation. The procedures were performed with the patients in the lithotomy position (the leg on the stone side is lowered) under general anesthesia. Patients underwent ureteroscopic pneumatic lithotripsy (Vibrolith,™ Elmed Lithotripsy Systems, Ankara, Turkey) for lower and middle ureteral impacted calculi. The operation was performed with a rigid 8F semirigid ureteroscope (Wolf Medical Instruments, Vernon Hills, IL) without ureteral dilatation. The ureteroscope was introduced just below the stone, and confirmation of its relation to the edematous and hyperemic ureteral mucosa was obtained by C-arm fluoroscopic imaging in cases where direct vision of the stone could not be obtained.

After the disintegration of the stone with the lithotripter, a safety Zebra guidewire was placed. The fragments were removed with a grasping forceps or appropriate basket catheters. After removal of the stone fragments, retrograde ureterography was performed to exclude perforation, and real-time fluoroscopic examination was performed for reassurance of the completeness of the stone removal. Double-J 4.8F multilength ureteral stents were placed cystoscopically in patients according to the consecutive alternating randomization order. Patients were discharged either at the same day or at postoperative day (POD) 1, unless the discharge was delayed for medical reasons.

All stents were cystoscopically removed at the third postoperative week. Intravenous pyelography was also performed in all patients after 3 months for the verification of ureteral patency and stone-free status. Except for the excluded patients, no patient needed rehospitalization or reoperation; in no patients did ureteral stricture develop.

Sociodemographic and clinical variables of the patients (age, sex, stone location, stone size, operative time, hospital stay, narcotic and nonnarcotic analgesic use), and postoperative complications (fever, pain delaying discharge, emergency department visit, urinary retention, stent-related irritative symptoms) were evaluated between the two groups.

Statistical analyses were performed with the Statistical Package for Social Sciences for Windows (Version 13.0, Chicago, IL) program. Continuous variables between the two groups were analyzed with the Student t test, and categorical variables with chi-square or Fisher exact test. Statistical significance was considered at P < 0.05.

Results

Patient characteristics and the results are shown in Table 1. Thirty-eight patients were male and 22 were female. Details of the sex distribution are shown in Table 1. The stone size ranged between 5 and 18 mm. Stones were located in the lower ureter in 45 patients (23 without stent, 22 with stent) and in the middle ureter in 15 (7 without stent, 8 with stent). There was no statistically significant difference in terms of stone size and mean hospital stay between the groups (Table 1). Operative time was significantly longer in the stent group (43.7 vs 30.5 minutes). Stent placement resulted in a mean of an extra $950 expenditure (data not shown) for stent and cystoscopic removal. Stone-free rates (97%; n = 29/30) were identical in both groups. Two patients (one in the stent group and one in the no-stent group) who were not stone free were successfully treated by shockwave lithotripsy (SWL); the patient in the no-stent group who was not stone free after ureteroscopic lithotripsy did not have stent placement before SWL.

Table 1.

Sociodemographic and Clinical Variables of Patients With and Without Stents After Uncomplicated Ureteroscopy for Impacted Stones

		Without stent	With stent
		(n = 30)	(n = 30)	P value
Age (mean ± SD)		46.5 ± 12.5	44.1 ± 15.2	0.51^a
Sex	Female (%)	12 (40)	10 (33)	0.59^b
Sex	Male (%)	18 (60)	20 (67)
Stone location	Lower ureter (%)	23 (77)	22 (63)	0.76^b
Stone location	Middle ureter (%)	7 (23)	8 (27)
Mean stone size; mm (mean ± SD)		7.5 ± 2.1	9.1 ± 4.5	0.08^a
Mean operative time; min. (mean ± SD)		30.5 ± 9.6	43.7± 11.6	< 0.001^a
Mean hospital stay; days (mean ± SD)		0.8 ± 0.4	0.9 ± 0.6	0.45^a
Narcotic analgesic use; <POD 5 (%)		29 (96.7)	19 (63.3)	0.004^b
Nonnarcotic analgesic use; <POD 5 (%)		27 (90)	22 (73.3)	0.18^b
Narcotic analgesic use; >POD 5 (%)		0 (0)	3 (10)	0.24^c
Nonnarcotic analgesic use; ^a >POD 5 (%)		2 (6,7)	17 (56.7)	0.0001^c

t test.

χ² test.

Fisher exact test.

POD = postoperative day.

Postoperative complications are presented in Table 2. Complications for the two groups were similar except for irritative voiding symptoms, which were statistically greater in the stent group (28 vs 3, P < 0.001). Ureteral stricture was not observed in any patient in both groups. There was no difference between the groups regarding postoperative fever. Although not statistically significant, delay in hospital discharge because of pain and emergency department visits was almost two times higher in patients in the no-stent group. On the other hand, urinary retention was more frequent and stent-related irritative symptoms were almost invariable in the stent group.

Table 2.

Postoperative Complications of Patients With and Without stents

	Without stent (n = 30)	With stent (n = 30)	P^a
Fever (%)	2 (6)	3 (10)	1
Pain delaying discharge (%)	7 (23)	3 (10)	0.299
Emergency department visit (%)	6 (20)	3 (10)	0.472
Stent-related irritative symptoms (%)	3 (10)	28 (93)	< 0.001^a
Urinary retention (%)	1 (3)	3 (10)	0.612

Fisher exact test.

In the stent group, stents had to be removed prematurely in three patients before the third postoperative week because of intolerance of severe stent-related irritative symptoms. These were the three patients who needed narcotic analgesic use at ≥ POD 5 (Table 1); on removal of the stent, all three patients immediately became symptom free.

On the operation day and until POD 5, narcotic (P = 0.004) and nonnarcotic analgesic (P = 0.18) use was more frequent in the no-stent group. At POD 5 and later, although narcotic and nonnarcotic analgesic use were frequently necessary in the stent group, both were almost unnecessary in the no-stent patients.

Discussion

There are myriads of ureteral stents used in association with different procedures, such as reconstruction of ureteropelvic junction obstruction, orthotopic urinary diversion, SWL, renal transplantation, ureteral obstruction (intrinsic or extrinsic), ureteroscopy, and ureteroscopic or nephroscopic management of stones or tumors.⁶ These ureteral stents include Cummings catheters, Double-J stents, single pigtail ureteral stents, and universal ureteral stents. These stents are generally used to prevent urinary obstruction after procedures such as SWL or ureteroscopic intervention, and to divert the urine stream for the facilitation of reconstructive healing of ureteroenteric anastomoses or orthothopic pouches.⁷ Long-term indwelling ureteral stents may cause a variety of complications, including stent-related irritative voiding symptoms, flank pain, suprapubic pain, stent fracture, ureteral erosion, and ureteroarterial fistula formation.⁸

On the other hand, ureteral stents may negatively impact the quality of life and can cause significant morbidity.⁹ Stent placement also increases the cost of patient care, becsuse of the cost of the stent and cystoscopic stent removal in cases where a pull string was not used. Moreover, cystoscopic stent removal has also its share of morbidity, albeit small, including infection. Occasionally, stents may migrate into the distal ureter; then ureteroscopic removal becomes necessary. This increases the cost and may result in patient morbidity. A multi-institutional, randomized study demonstrated significantly more postoperative flank pain, bladder pain, lower urinary tract symptoms, and overall pain in patients with vs without stents after ureteroscopy.¹⁰ Because stents have been implicated as the cause of these problems, decreasing their routine use may result in improved patient quality of life after ureteroscopic procedures.

Routine stent placement after ureteroscopy is a common procedure, particularly after ureteroscopic lithotripsy. Stones in the ureter can cause edema or mucosal inflammation at the location of a stone and, without stent placement, these changes may cause the patient to have obstructive symptoms and, potentially, strictures after the procedure. Ureteral stents were shown to prevent ureteral stricture formation after ureteroscopy by soft dilation of the ureter.^7,11 Smaller ureteroscopes can now provide stone fragmentation with minimal trauma and without the need for ureteral dilation.

A number of randomized trials in patients who were undergoing ureteroscopic stone removal investigated the effects of placing a stent at the termination of the procedure and concluded that the complication rates in patients were no different between the no-stent and the stent cohorts without impacting stone-free rates.^12

–15 Similarly, even in impacted ureteral stones, the stone-free rates as well as postoperative complications do not differ significantly between patients with and without stents in our study.

Cheung and associates¹³ compared stone-free rates, complications, and unplanned medical visits between the patients who had and who did not have ureteral stent placement after uncomplicated laser lithotripsy for ureteral stones. Their study included both impacted and unimpacted stones. They conclude that postoperative ureteral stent placement is not necessary after uncomplicated ureteroscopic lithotripsy, and the omission of the ureteral stent reduces the incidence of stent-related irritative symptoms (postoperative pain and urinary symptoms, including dysuria, loin pain, and hematuria), but does not prevent postoperative urinary sepsis and unplanned medical visits.

We included only impacted stones in our study. Although stent-related irritative symptoms are higher in our study, similar to their study, unplanned medical visits (emergency department visits) in our study are not equal in both groups; patients in the no-stent group had higher unplanned medical visits (although P = not significant).

The frequencies of delay in hospital discharge because of pain and emergency department visits in our study appeared to be almost two times higher in patients in the no-stent group, although the difference was not statistically significant. Emergency department visits were mainly necessary in patients with severe, intractable pain not relieved by oral analgesics. These patients received injectable analgesics in the emergency department for the relief of their severe pain. On the other hand, when we took a close look at the clinical situation, rather than the frequencies, these differences were not clinically disturbing. Discharge waqs delayed at most until POD 3 for pain management, and except for one patient (two emergency visits for a maximum of 1 hour at each occasion) in the no-stent group, all emergency department visits in both groups were for one time and for a maximum of 1 hour.

Regarding unplanned visits, the literature is diverse in terms of emergency department visit requirements. While emergency department visit requirement was reported to be almost none in one of the studies⁸ (both in the stent and no-stent group), it was reported to be quite high in another study (21% in the stent, 17% in the no-stent group).¹¹ Although there was no statistically significant difference between the stent and no-stent patients in this study,¹¹ no-stent patients had significantly higher emergency department visits in the studies by Borboroglu and colleagues¹⁰ and Damiano and coworkers.¹⁶ We also had higher emergency department visits in the no-stent group, but this was not statistically significant (Table 2, and discussion above).

In a recently published study including 220 patients (110 without stents and 110 with stents), although unplanned medical visits were more than two times higher in the no-stent group (4.5% vs 1.8%) the difference was also not statistically significant, similar to our study.¹⁷

Some investigators have suggested that stent placement after ureteroscopy may decrease the incidence of postoperative ureteral stricture formation.¹¹ This has not been documented yet in any controlled human study, however. Balloon dilatation of the distal ureter, which was shown to increase the risk of strictures in animal studies, is still routinely performed at many centers.¹⁸ We do not perform dilatation of the ureteral orifice, however, and we did not have any stricture in either stent or no-stent patients in our study.

Previous studies reported that the application of stents itself increased the duration of the operation.^11,19 Accordingly, we have found that the stent group had significantly increased operative duration. This is reasonable because of the additional time necessary for the placement of the stent and perhaps slightly (but not significantly) bigger mean stone size in the stent group in our series.

Approximately 85% to 90% of patients with indwelling ureteral stents reported irritative voiding symptoms, including frequency, urgency, and dysuria as well as flank pain, suprapubic pain, and hematuria.²⁰ Currently, a wide variety of medical treatments are available to relieve irritative bladder symptoms, including analgesic, alpha receptor blocker, and anticholinergic drugs. These medications, however, come at the considerable expense of drug side effects.²⁰

We examined analgesic use according to time-related trends and saw that at POD 5 and later, although narcotic and nonnarcotic analgesic use was frequently necessary in the stent group, both were almost unnecessary in the no-stent patients. Nonnarcotic analgesics were necessary in the majority of the patients until stent removal in the stent group (P = 0.0001). On the other hand, narcotic requirement especially was significantly higher (P = 0.004) in no-stent patients in the first 4 PODs.

A recent meta-analysis including 10 studies (n = 891) analyzed the effect of ureteral stent placement after uncomplicated ureteroscopic lithotripsy. This study showed that, although the complications were 4% lower in the stent group, this difference was not statistically significant (P = 0.175).²¹ Except for stent-related symptoms, our study also failed to show a significant difference in complications between stent and no-stent groups (Table 2).

Electrohydraulic lithotripters were known to be more traumatic to ureteral mucosa when compared with the others (pneumatic, ultrasonic, or laser devices).²¹ The literature is not clear, however, regarding whether stent placement can be eliminated safely in using one of these technologies in head to head comparison with the others. On the other hand, our series includes only impacted stones, where the literature is more deficient.

Conclusion

Double-J ureteral stent placement does not appear to be clearly advantageous after uncomplicated ureteroscopic lithotripsy, according to the current literature data. Besides, there is additional cost for the ureteral stent, and stent removal necessitates an additional invasive procedure and inherent cost. To the best of our knowledge, however, this is the first study that addresses whether ureteral stent placement is necessary after uncomplicated ureteroscopic lithotripsy for impacted ureteral stones. Our study showed that routine placement of a ureteral stent is not mandatory in patients without complication after ureteroscopic lithotripsy for impacted ureteral stones. We think that stent placement can be argued with the patients preoperatively and final agreement can be settled in the light of the data presented above.

Disclosure Statement

No competing financial interests exist.

Footnotes

Abbreviations Used

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