A Randomized Outcomes Trial of Ureteral Stents for Extracorporeal Shock Wave Lithotripsy of Solitary Kidney or Proximal Ureteral Stones

Impact of differential ureteral stent diameters on clinical outcomes after ureteroscopy intracorporeal lithotripsy: A systematic review and meta-analysis

In this meta-analysis we assessed whether the diameter of ureteral stents (4.7-5-Fr, 6-Fr) has an impact on the rate of occurrence of urinary tract symptoms and complications after successful URS and intracorporeal lithotripsy. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A rigorous search for relevant studies published in MEDLINE, Embase, and the Cochrane Controlled Trials Register was conducted to find informative randomized controlled trials. The reference lists of relevant articles were also manually searched and reviewed. The protocol was prospectively registered at PROSPERO (CRD42020202164). All statistical evaluations were performed using RevMan software version 5.3.0. Seven articles comprising 547 patients were included in the meta-analysis. After placement of ureteral stents with different diameters for approximately 1 week, we found that ureteral stents with smaller diameters (4.7-5-Fr) were associated with significant improvements in the main domain scores on the Ureteral Stent Symptom Questionnaire, such as urinary symptoms (mean difference -4.47, 95% confidence interval -5.87 to -3.08; P < 0.00001) and body pain (mean difference -2.48, 95% confidence interval -4.37 to -0.59; P = 0.01), but poor outcomes in stent migration compared to ureteral stents with a 6-Fr diameter (odds ratio 3.00, 95% confidence interval 1.06-8.51; P = 0.04). However, there were no significant differences in Ureteral Stent Symptom Questionnaire scores with regard to work performance (mean difference -0.56, 95% confidence interval -2.52 to 1.40; P = 0.58), general health (mean difference -2.29, 95% confidence interval -4.95 to 0.37; P = 0.09), additional problems (mean difference -0.43, 95% confidence interval -1.02 to 0.15; P = 0.15), and complications such as fever (odds ratio 0.75, 95% confidence interval 0.24-2.39; P = 0.63). Ureteral stents with a diameter of 4.7-5-Fr have better outcomes than those with a diameter of 6-Fr, based on the Ureteral Stent Symptom Questionnaire pain and urinary tract symptoms scores. However, they are more prone to migration compared to those with a larger diameter.

Efficacy of commercialised extracorporeal shock wave lithotripsy service: a review of 589 renal stones

BACKGROUND

Extracorporeal shockwave lithotripsy (ESWL) is the management of choice for renal stones 20 mm or smaller, with a stone clearance rate of up to 89%. The purpose of the present is to investigate the efficacy of a commercialised ESWL service, being performed as an outsourced treatment using a mobile lithotripsy system on an outpatient basis. Furthermore, the study aims to evaluate the risk of needing treatment with an internal ureteral double-J stent (JJ) after ESWL treatment.

METHODS

During an eight-year period, 461 patients with a total of 589 renal stones were treated using a mobile lithotripsy system at a single Danish institution. A commercial company performed all treatments using a Storz Modulith SLK® system. Each stone was prospectively registered according to size, intra renal location and the presence of a JJ at the time of treatment. The number of required ESWL treatments and auxiliary procedures were retrospectively evaluated.

RESULTS

The success rate after the initial ESWL procedure was 69%, which increased to an overall success rate of 93% after repeated treatment. A negative correlation was found between stone size and the overall success rate (r = -0.2, p < 0.01). The upper calyx was associated with a significantly better success rate, but otherwise intra renal stone location was not predictive for treatment success. A total of 17 patients (2.9%) required treatment with a JJ after the ESWL procedure. No significant difference was observed between the stone size or intra renal location and the risk of needing treatment with JJ after ESWL.

CONCLUSIONS

Commercialised ESWL treatment can achieve an overall success rate of more than 90% using a mobile lithotripsy system. As expected, an inverse relation between stone size and success rate was found. Patients who do not require treatment with a JJ prior to ESWL will only rarely need treatment with a JJ after ESWL, irrespective of stone size and intra renal stone location.

Can a brief period of double J stenting improve the outcome of extracorporeal shock wave lithotripsy for renal calculi sized 1 to 2 cm?

Purpose

Extracorporeal shock wave lithotripsy (ESWL) is an established modality for renal calculi. Its role for large stones is being questioned. A novel model of temporary double J (DJ) stenting followed by ESWL was devised and outcomes were assessed.

Materials and Methods

The study included 95 patients with renal calculi sized 1 to 2 cm. Patients were randomized into 3 groups. Group 1 received ESWL only, whereas group 2 underwent stenting followed by ESWL. In group 3, a distinct model was applied in which the stent was kept for 1 week and then removed, followed by ESWL. Procedural details, analgesic requirements, and outcome were analyzed.

Results

Eighty-eight patients (male, 47; female, 41) were available for analysis. The patients' mean age was 37.9±10.9 years. Stone profile was similar among groups. Group 3 received fewer shocks (mean, 3,155) than did group 1 (mean, 3,859; p=0.05) or group 2 (mean, 3,872; p=0.04). The fragmentation rate was similar in group 3 (96.7%) and groups 1 (81.5%, p=0.12) and 2 (87.1%, p=0.16). Overall clearance in group 3 was significantly improved (83.3%) compared with that in groups 1 (63.0%, p=0.02) and 2 (64.5%, p=0.02) and was maintained even in lower pole stones. The percentage successful outcome in groups 1, 2, and 3 was 66.7%, 64.5%, and 83.3%, respectively (p=0.21). The analgesic requirement in group 2 was higher than in the other groups (p=0.00). Group 2 patients also had more grade IIIa (2/3) and IIIB (1/2) complications.

Conclusions

Stenting adversely affects stone clearance and also makes the later course uncomfortable. Our model of brief stenting followed by ESWL provided better clearance, comfort, and a modest improvement in outcome with fewer sittings and steinstrasse in selected patients with large renal calculi.

Meta-Analysis of Stenting versus Non-Stenting for the Treatment of Ureteral Stones

Background and aim

Ureteroscopic lithotripsy (URL) and extracorporeal shock wave lithotripsy (ESWL) are two widely used methods for the treatment of ureteral stones. The need for ureteral stenting during these procedures is controversial. In this meta-analysis, we evaluated the benefits and disadvantages of ureteral stents for the treatment of ureteral stones.

Methods

Databases including PubMed, Embase and Cochrane library were selected for systematic review of randomized controlled trials (RCTs) comparing outcomes with or without stenting during URL and ESWL. Meta-analysis was performed using RevMan 5.3 and STATA 13.0 software.

Results

We identified 22 RCTs comparing stenting and non-stenting. The stented group was associated with longer operation time (WMD: 4.93; 95% CI: 2.07 to 7.84; p < 0.001), lower stone-free rate (OR: 0.55; 95% CI: 0.34 to 0.89; p = 0.01). In terms of complications, the incidence of hematuria (OR: 3.68; 95% CI: 1.86 to 7.29; p < 0.001), irritative urinary symptoms (OR: 4.40; 95% CI: 2.19 to 9.10; p < 0.001), urinary infection (OR: 2.23; 95% CI: 1.57 to 3.19; p < 0.001), and dysuria (OR: 3.90; 95% CI: 2.51 to 6.07; p < 0.001) were significantly higher in the stented group. No significant differences in visual analogue score (VAS), stricture formation, fever, or hospital stay were found between stenting and non-stenting groups. The risk of unplanned readmissions (OR: 0.63; 95% CI: 0.41 to 0.97; p = 0.04) was higher in the non-stented group.

Conclusions

Our analysis showed that stenting failed to improve the stone-free rate, and instead, it resulted in additional complications. However, ureteral stents are valuable in preventing unplanned re-hospitalization. Additional randomized controlled trials are still required to corroborate our findings.

Ureteral stenting can be a negative predictor for successful outcome following shock wave lithotripsy in patients with ureteral stones

Purpose

To evaluate ureteral stenting as a negative predictive factor influencing ureteral stone clearance and to estimate the probability of one-session success in shock wave lithotripsy (SWL) patients with a ureteral stone.

Materials and Methods

We retrospectively reviewed the medical records of 1,651 patients who underwent their first SWL. Among these patients, 680 had a ureteral stone measuring 4–20 mm and were thus eligible for our study. The 57 patients who underwent ureteral stenting during SWL were identified. Maximal stone length (MSL), mean stone density (MSD), skin-to-stone distance (SSD), and stone heterogeneity index (SHI) were determined by pre-SWL noncontrast computed tomography.

Results

After propensity score matching, 399 patients were extracted from the total patient cohort. There were no significant differences between stenting and stentless groups after matching, except for a higher one-session success rate in the stentless group (78.6% vs. 49.1%, p=0.026). In multivariate analysis, shorter MSL, lower MSD, higher SHI, and absence of a stent were positive predictors for one-session success in patients who underwent SWL. Using cutoff values of MSL and MSD obtained from receiver operator curve analysis, in patients with a lower MSD (≤784 HU), the success rate was lower in those with a stent (61.1%) than in those without (83.5%) (p=0.001). However, in patients with a higher MSL (>10 mm), the success rate was lower in those with a stent (23.6%) than in those without (52.2%) (p=0.002).

Conclusions

Ureteral stenting during SWL was a negative predictor of one-session success in patients with a ureteral stone.

What is the best option for 10-20mm renal pelvic stones undergoing ESWL in the pediatric population: stenting, alpha blockers or conservative follow-up?

OBJECTIVE

In this study we aimed to identify the effect of three different modalities (stenting, doxazosin and conservative follow-up) on stone free rates and complication rates for 10-20mm renal pelvic stones in pediatric patients who underwent shock wave lithotripsy.

PATIENTS AND METHODS

In this study data from 241 renal units (RUs) of 195 consecutive patients with 10-20mm renal pelvis stones were analyzed retrospectively. There were 3 groups in the study; 56 (23.2%) RUs with ureteral stenting were categorized as group 1, and 39 (16.2%) RUs that received doxazosin were categorized as group 2. The remaining 146 (60.6%) RUs without history of ureteral stenting or alpha-blockers usage were categorized as group 3. Patient demographics, stone characteristics, stone free rates (SFRs), time to stone expulsion and complications were documented and compared in each group.

RESULTS

Mean age of the population was 6.6 years and mean stone size was 13.8 ± 2.9 mm. Demographic characteristics of the 3 groups were not significantly different. SFRs of the three groups were 89.2%, 87.1% and 82.1% (p = 0.275). Mean time to stone expulsion for groups 1 and 2 were 17.4 and 21.8 days respectively and significantly lower than that in group 3 (31.3 days).

CONCLUSIONS

Ureteral stenting or doxazosin for shockwave lithotripsy (SWL) is not superior to watchful waiting in terms of SFR and complications however both modalities shorten the stone expulsion time for 10-20mm renal pelvis stones in the pediatric population.

Extracorporeal shock wave lithotripsy in impacted upper ureteral stones: a prospective randomized comparison between stented and non-stented techniques

OBJECTIVES

To assess the need for pre-extracorporeal shock wave lithotripsy (pre-ESWL) stenting in management of impacted upper ureteral stones of size < or = 2 cm and to verify whether stenting would influence the success of therapy.

METHODS

Between 2007 and 2008, a total of 60 patients with solitary, radio-opaque impacted upper ureteral stones measuring < or = 2 cm were divided into 2 equal groups: a stented group with a Double-J stent fixed pre-ESWL and a non-stented group treated by in situ ESWL. All patients were treated by ESWL using Dornier Doli S lithotripter. Results were compared in terms of clearance rates, number of shock waves and sessions, morbidity, and incidence of complications. Pretreatment KUB (kidneys, ureters, and bladder) and intravenous pyelogram and post-treatment KUB were used to evaluate fragmentation and clearance.

RESULTS

Overall stone-free rate was 88.3%. No significant statistical difference was observed in stone-free rate between the stented and non-stented groups being 90% and 86.7%, respectively (P = .346). One session was required in 28.3% of patients, whereas multiple sessions were required in 71.7% of patients. No significant statistical difference was noted in re-treatment rate in the 2 groups. Patients in the stented group significantly complained of side effects attributable to the stent predominantly dysuria, urgency, frequency, and suprapubic pain.

CONCLUSIONS

ESWL is an effective and reasonable initial therapy in the management of impacted upper ureteral stones measuring < or = 2 cm. Pre-ESWL ureteral stenting provides no additional benefit over in situ ESWL. Moreover, ureteral stents are associated with significant patient discomfort and morbidity.

Rapid, economical treatment of large impacted calculi in the proximal ureter with ballistic ureteral lithotripsy and occlusive, percutaneous balloon catheter: the high pressure irrigation technique

PURPOSE

We describe our innovative technique for the treatment of large calculi (greater than 1.5 cm) of the proximal ureter.

MATERIALS AND METHODS

Between 2003 and 2005 we positioned an 8Ch pyelostomy in 25 patients diagnosed with impacted calculi of the proximal ureter greater than 1.5 cm on ultrasound, direct x-ray of the abdomen, and/or computerized tomography and subsequent retrograde pyelography. After 30 days all patients underwent combined treatment in the Valdivia supine position, including positioning a 0.035-inch guidewire through the pyelostomy into the ureter up to above the calculus, pyelostomy removal and insertion onto the guide of a 7Ch balloon occlusion catheter, which was inflated in the ureter immediately above the calculus. Ureteral lithotripsy was done with an 8.5 to 11.5Ch ureteroscope (Wolf, Dudley, Massachusetts) with a 6Ch operating channel and a Calcusplit ballistic probe, alternating high antegrade pressure by the balloon catheter and retrograde pressure using the ureteroscope, as required. After lithotripsy and fragment dislocation the ureteroscope was retracted with rapid flow antegrade irrigation. At the end of the procedure after antegrade contrast medium followup the balloon catheter was retracted as far as the pelvis as a nephrostomy. We analyzed operative time, the number of postoperative recovery days, the incidence of complications during and after surgery, and the stone-free rate immediately, after 5 days and after 1 month.

RESULTS

Average calculus size was 1.7 cm. Ten patients presented with multiple ureteral bending upon diagnosis, which was no longer found at surgery with a consequent lack of difficult ureteroscope feeding. Significant edema downstream of the calculus was present in all cases. High pressure irrigation, a rigid ballistic probe and retrieving forceps enabled the dislocation of even larger fragments from the original calculous site in all cases. Antegrade high pressure irrigation after lithotripsy enabled the complete clearance of calcareous fragments as far as the bladder without the need for ancillary maneuvers. We observed no cases of calcareous fragment push-back. No retroperitoneal extravasation, or pyelolymphatic or pyelovenous backflow was observed. Average procedure time was 33 minutes. The renal-ureteral stone-free rate was 100% at the end of the procedure and all calcareous fragments were in the bladder. We did not observe any ureteral lesions. In no case was there onset of fever. Average postoperative hospitalization was 2 days. Followup with contrast material after 5 days showed a renal-ureteral stone-free rate of 100% and a bladder stone-free rate of 84%. The nephrostomy was removed at an average of 5.5 days.

CONCLUSIONS

Compared to the techniques described in the medical literature our method appears to have certain advantages, including a mini-invasive approach to the renal pelvis compared to that of percutaneous nephrolithotomy with protection of the renal parenchyma from high pressure, rigid ureteroscope use, which provides a high level of maneuverability and low operating costs, ballistic probe use, which provides lower costs and higher speeds than the laser, and balloon catheter use, which removes the risk of push-back and enables push-down of the fragments without any further ancillary maneuvers. The balloon catheter also enables contrast medium followup and immediate postoperative drainage. The speed of the procedure and the ability to adjust antegrade or retrograde flow with variable pressure and direction make this technique highly suitable for the complete resolution of large, impacted calculi of the proximal ureter.

Ureteral Expanding Stent: A New Device for Urolithiasis

BACKGROUND AND PURPOSE

We investigate a ureteral stent with radially expanding baskets producing passive dilation of the ureter for passage, capture, and removal of small ureteral stones.

PATIENTS AND METHODS

Polyurethane ureteral stents were slit to open 15 to 17 baskets along the length. The baskets are designed to dilate the ureter passively and capture stones <or=5 mm. Forty-two patients had these stents placed for stones at nine medical centers. Stone size ranged from 2 to 30 mm, while fragment size ranged from 1 to 8 mm. The locations of the stones ranged from the kidney to the lower ureter. The Ureteral Expanding Stent was inserted in the closed position, similar to a standard ureteral stent, and left in place for an average of 11 days.

RESULTS

The device was inserted and extracted safely in all patients. Most patients experienced pain at an average rating of 3.7 of 10 on a visual analog scale. All stents were removed without significant morbidity. In 36 patients (86%), stones were removed with the stent (n=18) or passed while the stent was in place (n=18). The largest stone captured was 6 mm.

CONCLUSIONS

The Ureteral Expanding Stent (OPEN-Pass) was used safely in 42 patients with stones. The device captured ureteral stones and facilitated stone passage around it. Stent retention or ureteral injury as a result of stone entrapment did not occur. The Ureteral Expanding Stent represents a new stone-removal and ureteral-dilation tool worthy of further clinical study.

Use of double-J stents prior to extracorporeal shock wave lithotripsy is not beneficial: results of a prospective randomized study

OBJECTIVES

Since introduction of extracorporeal shockwave lithotripsy (ESWL) in treating patients with urinary tract stones in our clinic for the first time in our city Aden 5 years ago, we stented all patients with kidney stone >1 cm routinely before the procedure. Our aim of this study is to compare symptoms and complications of patients with and without stenting.

PATIENTS AND METHODS

In 2003, 120 patients with renal stone(s) amenable to ESWL management were prospectively treated in two groups: stented (60 patients) and unstented (60 patients). All patients were admitted for 48 h after ESWL and then followed for 3 months after discharge by the same treating group of doctors. Patients were followed-up radiographically to assess stone-free rate after 1 and 3 months.

RESULTS

There was no statistical difference in flank or abdominal pain, nausea, vomiting, transient hematuria, temperature or use of analgesics on the first and second day after ESWL in the stented or unstented group. Fifty-one patients (85%) of stented group complained of side effects attributable to stent including urinary frequency and urgency, bladder pain and hematuria with urination, which in all patients but 3 of them were treated as out patient and one of the unstented group, who were readmitted because of mild to severe pain, fever, and chills. In all stented patients, we removed the stents after 2 weeks; except in readmitted patients where it was removed earlier. Plain X-ray film was done for all patients after one and 3 months. Eight patients with stents (6.7%) had >5 mm residual fragments. In these patients second ESWL session was necessary. Three months stone-free rate was 88% in stented and 91% in unstented group, respectively.

CONCLUSION

The use of double-J stents prior to ESWL treatment is not beneficial.

Extracorporeal shock wave lithotripsy in children: evaluation of the results considering the need for auxiliary procedures

OBJECTIVE

To retrospectively evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) in children with renal stones, with regard to ability of ureters to transport the fragments, and need for adjunctive procedures.

PATIENTS AND METHODS

Between January 2000 and November 2004, 60 children (24 girls and 36 boys) with a total of 72 stones of the upper urinary tract were treated by ESWL using a PCK V5 lithotriptor. Patients with anatomical abnormalities and staghorn stones were excluded from the study. Stone size ranged from 4 to 28 mm. Mean number of shock waves was 1430 (range 600-2000) per ESWL session and mean energy used for stone disintegration was 12 kV (range 6-18). At 24-48 h after ESWL, a plain film or renal ultrasound was obtained to evaluate stone fragmentation.

RESULTS

Our stone-free rate after one session of ESWL was 92.8% and 81.2% for patients with stones smaller than 10mm and stones between 10 and 28 mm, respectively. Seven (11.6%) patients developed distal ureteral steinstrasse, and the stone size was 15-20 mm and 20-28 mm in two and five patients, respectively. The steinstrasse completely cleared under meticulous follow-up. No patient needed an adjunctive procedure, such as a double-J stent or nephrostomy tube placement, or ureteroscopic stone manipulation.

CONCLUSION

A child's ureter is capable of transporting the fragments after lithotripsy. Interventional procedures should be a last resort. Expectant management is usually adequate even in patients who develop steinstrasse after ESWL.

Incontinence after radical prostatectomy: surgical treatment options

PURPOSE OF REVIEW

Stress urinary incontinence is an uncommon finding in healthy men. Following radical prostatectomy, however, stress urinary incontinence is the most important complication influencing patient morbidity following surgery and influencing satisfaction, regardless of the surgical technique applied. Conservative treatment options centre at early restoration of bladder and pelvic floor function. When significant and bothersome stress urinary incontinence persists, even after six to 12 months active treatment follow-up, surgical restoration of continence seems advisable.

RECENT FINDINGS

Two themes emerge in reviewing the recent publications in this field. Implantation of the hydraulic artificial urinary sphincter is still the gold standard, particularly in severe cases. Alternatively, new techniques and other artificial materials are gaining favour, aiming at a large cohort of patients with less severe incontinence, which have been not treated or overtreated so far. Advances in both areas are covered within this review article in detail.

SUMMARY

For treatment of incontinence following prostatectomy, a large variety of surgical techniques are readily available and have proven to be helpful tools in making patients' uncomfortable lives much easier. In addition, the wide armamentarium of artificial materials and techniques may help to choose the proper surgical technique for every patients' needs.

Minimizing symptoms in patients with ureteric stents

PURPOSE OF REVIEW

The current approaches for minimizing symptoms in patients with ureteric stents were reviewed utilizing a literature search on Pubmed using the keywords stent, symptom, and ureter.

RECENT FINDINGS

Ureteral stents are widely used in urological procedures for maintaining upper urinary tract drainage to relieve obstruction, pain, or infection. Indwelling stents, however, are associated with significant morbidity such as infection, encrustation, hematuria, and bothersome symptoms. Minimizing these issues has become paramount in the design of new ureteral stents. This article will review current and novel ways to minimize stent-related morbidity.

SUMMARY

Currently, there is no ideal stent that relieves obstruction, is resistant to infection and encrustation, and is comfortable for patients. Advances in biomaterials and design will result in a more biocompatible stent that also has patient comfort in mind.

Does the Size of Ureteral Stent Impact Urinary Symptoms and Quality of Life? A Prospective Randomized Study

OBJECTIVE

To evaluate the effect of stent diameter on patients' symptoms and quality of life (QoL) by using dedicated questionnaires.

METHODS

We prospectively enrolled 34 patients with unilateral ureteral obstruction due to urinary stone undergoing to ureteral stenting (17 pts with 4.8 F and 17 pts with 6 F) before treatment of stone disease. Twenty-one patients with lower urinary symptoms from other causes were used as a control group. Two questionnaires, one on QoL and another on stent specific symptoms, were administered to patients one week after stent positioning and 4 week after removal.

RESULTS

There was a significant association between stent state and answers on pain and discomfort on QoL questionnaire. A high percentage of patients reported anxiety and depression associated with the stent. Similar significant association was found between stent state and urinary symptoms and pain. No differences in QoL and urinary symptoms and pain were detected using stents with different size.

CONCLUSIONS

Ureteral stents are invariably associated with urinary symptoms and impaired QoL. We did not find any difference between stent with different size, whereas there was a tendency for stent with smaller diameter to dislodge more often.

Second Prize: Double-Blind Randomized Controlled Trial Assessing the Safety and Efficacy of Intravesical Agents for Ureteral Stent Symptoms after Extracorporeal Shockwave Lithotripsy

BACKGROUND AND PURPOSE

Ureteral stents are a significant source of pain and discomfort for many urologic patients. A novel approach to addressing this problem is the intravesical instillation of a selected pharmacologic agent after stent insertion. The purpose of this study was to assess the safety and efficacy of intravesical instillation of various agents in reducing ureteral stent-associated discomfort in patients requiring a stent after extracorporeal shockwave lithotripsy (SWL).

PATIENTS AND METHODS

In this double-blind prospective trial, 42 patients were randomized to receive intravesical instillation of one of three agents (oxybutynin, alkalinized lidocaine, or ketorolac) or a control solution (0.9% sodium chloride) immediately after stent insertion at time of SWL. The four groups of patients were demographically similar. Preoperative, intraoperative, and postoperative data were collected prospectively and analyzed statistically. The primary outcome measure was reduction in ureteral stent symptoms, and the secondary outcome measure was the safety of intravesical instillation of each agent through assessment of drug-related adverse events.

RESULTS

There were no intraoperative or postoperative complications, nor were there any serious side effects attributable to any of the intravesically instilled agents. There was a statistically significant decrease in stent-related discomfort at the 1-hour time point in the group of patients who received intravesical ketorolac compared with the control group.

CONCLUSIONS

Intravesical instillation represents a novel approach to the problem of ureteral stent-related discomfort. From our results, ketorolac appears to be the most effective intravesical agent in reducing stent-related patient discomfort, and we have established that intravesical instillation of ketorolac is safe in humans.

The use of stents in contemporary urology

PURPOSE OF REVIEW

Ureteral stents are a mainstay of today's urological armamentarium. This review critically evaluates the recent literature and provides a concise summary of the use of stents in urology today. While stents are used in many reconstructive urologic procedures, this review focuses on the use of stents in urolithiasis as it pertains to ureteroscopy, shockwave lithotripsy, and ureteropelvic junction obstruction.

RECENT FINDINGS

Ureteral stents are associated with irritative symptoms, hematuria, infection, and encrustation. A new validated quality of life and impact questionnaire has been developed and has shown that 76% of patients suffer at least some type of morbidity related to the stent. Many studies in the recent literature have re-examined our use of stents today. For example, concepts regarding stenting following ureteroscopy, before shockwave lithotripsy, and following endopyelotomy have undergone an evolution based on the results of randomized, prospective studies.

SUMMARY

The ureteral stent is an invaluable urological tool and its indications are evolving as are new stent technologies to improve patient care and comfort.

Impact of ureteral stent diameter on symptoms and tolerability

BACKGROUND AND PURPOSE

Indwelling double-pigtail ureteral stents are frequently associated with debilitating symptoms. A randomized study was performed to evaluate the effect of stent diameter (4.7F v. 6F) on symptoms and tolerability.

PATIENTS AND METHODS

Between February and October 2000, 46 consecutive patients undergoing ureteroscopy for stone disease were randomly assigned to receive either a 4.7F (group I) or a 6F (group II) ureteral stent following the procedure. The patients were asked to leave their stents in place for minimum of 7 days. Pain and irritative urinary symptoms in the two groups were compared according to a scale ranging from 0 (none) to 5 (severe). The two groups were also compared for stone size and location, rigid v. flexible ureteroscopy, anesthesia, stent migration, and ureteral dilation.

RESULTS

There were no differences between the groups in terms of pain (P = 0.28) or irritative symptoms (P = 0.37). There was a tendency for stents in group I to migrate distally and dislodge more often than those in group II (32% v 10%).

CONCLUSIONS

When stent insertion following ureteroscopy is deemed necessary, a minimum diameter of 6F is recommended.