Use of a magnetic double J stent in pediatric patients: A case-control study at two Canadian pediatric centers

Current Status of Ureteric Stents on Extraction Strings and Other Non-cystoscopic Removal Methods in the Paediatric Setting: A Systematic Review on Behalf of the European Association of Urology (EAU) Young Academic Urology (YAU) Urolithiasis Group

Ureteric stents are an important tool in urology and have a wide range of indications. While they offer a number of advantages, limitations remain despite modern advancements. These include discomfort, migration and encrustation. Standard removal is via cystoscopy but in the paediatric setting this mandates general anaesthetic, which holds disadvantages. Alternative removal methods include use of extraction strings and magnetic retrieval devices, which can be performed in the outpatient setting. This systematic review evaluates the safety and efficacy of different non-cystoscopic methods for stent removal in the paediatric setting.

Evolving trends in peri-operative management of pediatric ureteropelvic junction obstruction: working towards quicker recovery and day surgery pyeloplasty

OBJECTIVE

To describe the evolution of practice patterns for pediatric pyeloplasty and determine how these changes have impacted length of stay (LOS), reoperation rates and return emergency department (ER) visits.

METHODS

We reviewed our pyeloplasty database from 2008 to 2020 at a quaternary pediatric referral center and we included children 0-18 years undergoing pyeloplasty. Variables captured included: age, sex, baseline and follow-up anteroposterior diameter (APD) and differential renal function (DRF). We also collected data on the use of drains, catheters and/or stents, nausea and vomiting prophylaxis, opioids, regional anesthesia, and non-opioid analgesia. Outcomes were LOS, reoperation rates and ER visits.

RESULTS

A total of 554 patients (565 kidneys) were included. Reoperation rate was 7%, redo rate 4% and ER visits 17%. There was a trend towards less opioids, indwelling catheters and internal stents and increasing non-opioid analgesia, externalized stents, and regional anesthesia during the study period. Same-day discharge (SDD) was possible for 88 (16%) children with no differences in reoperation or readmission rates between SDD and admitted (ADM). There was a difference in ER visits (21 [24%] vs. 26 [6%]; p = 0.04) for SDD vs. ADM, respectively. On multivariate analysis, the only predictor of ER visits was younger age. Patients < 7 months were more likely to present to ER (15/41; 37% vs. 6/47, 13%; p = 0.009). Multivariate analysis determined indwelling catheters and opioids were associated with ADM while dexamethasone and ketorolac with SDD.

CONCLUSION

Progressive changes in care have contributed to a shorter LOS and increasing rates of SDD for pyeloplasty patients. SDD appears to be feasible and does not result in higher complication rates. These data support the development of a pediatric pyeloplasty ERAS protocol to maximize quicker recovery and foster SDD as a goal.

Comparison between internal double J and external pyeloureteral stents in open pediatric pyeloplasty: A multicenter study

INTRODUCTION AND OBJECTIVE

Anderson-Hynes dismembered pyeloplasty is considered the standard surgical treatment for ureteropelvic junction obstruction (UPJO). After pyeloplasty, stent drainage remains controversial. The commonly used stents are either an internal double-J (DJ) or an externalized pyeloureteral (PU) stents. We evaluated the outcome of using DJ versus PU stents following open pyeloplasty for UPJO in children.

STUDY DESIGN

We retrospectively evaluated 175 patients who underwent primary open pyeloplasty in two tertiary hospitals. A total of 110 patients underwent internal DJ stent insertion (63%) while 65 patients (37%) underwent placement of external PU stent. The type of stent used at the time of surgery was according to surgeon preference and experience. Operative time, postoperative hospital stay, overall complications and success rates were compared between the two groups.

RESULTS

The mean age was 3.8 years, and the mean follow-up was 4 years. Mean operative time was similar in the two groups (145 min). Mean hospital stay was 3.7 and 4.2 days in DJ and PU stent, respectively (p = 0.003) Summary Table . Postoperative complication developed in 9 out of 110 patients with DJ stent (8%), while complications developed in 6 out of 65 patients with PU stent (9%) (p = 0.81). Success rate of pyeloplasty was 95.5% for DJ group versus 97% for PU group (p = 0.63).

DISCUSSION

Dismembered pyeloplasty remains the standard treatment of choice as a surgical management for UPJO. A debate is still there in respect to the method of PU anastomotic stenting and which stent can be used. The major advantage for external PU stents is that it can be removed safely in the outpatient clinic without any sedation preventing the risk of repeated exposure to general anesthesia. Internal DJ stent provides a shorter hospital stay and comparable complication and success rates compared with PU stent. If we manage to overcome the longer DJ stent duration and facilitate early removal by an easy mode, that does not require another anesthesia at that moment we can find the optimal stent for all pyeloplasty cases.

CONCLUSIONS

The two types of stents are comparable as regard overall complication and success rates after pyeloplasty. Although internal DJ stent insertion provides a relatively shorter hospital stay, a second operating room visit and anesthesia for removal remains unavoidable.

Outcomes and costs analysis of Externalized PyeloUreteral versus internal Double-J ureteral stents after paediatric laparoscopic Anderson-Hynes pyeloplasty

BACKGROUND

The gold standard treatment for Uretero-Pelvic Junction Obstruction (UPJO) is laparoscopic dismembered pyeloplasty according to the Anderson-Hynes technique. The internal Double-J ureteral (DJ) and the Externalized PyeloUreteral (EPU) stents are usually the drainage of choice. Only a few articles have compared the clinical impact of the different drainage techniques on the perioperative morbidity and none presented a cost analysis of the incurred hospital stay.

OBJECTIVE

To present the clinical outcome and financial analysis of a cohort of children who underwent a laparoscopic pyeloplasty comparing the use of the DJ versus EPU stent.

STUDY DESIGN

Retrospective study of consecutives children who underwent laparoscopic Anderson-Hynes pyeloplasty in a single tertiary paediatric referral centre from January 2017 to March 2020. Patients were grouped according to the type of stent used: DJ stent vs EPU stent.

RESULTS

Fifty-three laparoscopic pyeloplasties were performed on 51 patients: 27 (50.9%) had an EPU stent and 26 (49.1%) a DJ stent. There was no statistically significant difference between the two patient groups with regards to surgical time, hospital stay, stent-related complications or the need for re-do surgery. All the EPU stents were removed with an outpatient admission 8.1 days ± 3.1 after surgery while the DJ stents were removed with a cystoscopy 61.6 days ± 30.2 after surgery (p value < 0.001). On a financial analysis (Figure), the hospital costs for stent removal were significantly lower for the EPU stent group (£ 686.7 ± 263.4 vs £ 1425 ± 299.5, p value < 0.01).

DISCUSSION

Both drainage methods have some disadvantages. Possible complications associated with DJ stents include migration and artificial vesicoureteral reflux which may lead to higher incidence of Urinary Tract Infections. Possible disadvantages of the EPU stent insertion are related to the damage of the renal parenchyma and to the risk of developing skin site infections and urinary leaks. However, in our series the EPU stent has not been associated with a higher incidence of bleeding, leakage or discomfort. In addition to clinical considerations, there is a financial implication to be considered. With this regard, the EPU stent was associated with a significant reduction in the incurred hospital costs.

CONCLUSIONS

The use of DJ and EPU stents is equivalent in regards of overall complications and success rates. DJ and EPU stents provided comparable success and complication rates, however the latter avoids the need of an additional general anaesthesia and reduces the overall incurred hospital costs.

Quantifying the forces needed for ureteral stent removal: Initial evaluation of magnetic stent removal devices on benchtop and porcine models

BACKGROUND

Indwelling ureteral stents are commonly used in pediatric surgeries for kidney stones and urinary tract obstruction, but often require instrumentation or anesthesia for removal. We evaluated the use of novel magnet devices to remove indwelling ureteral stents with a distally attached magnetic bead. Since the forces required for stent removal are unknown, we aimed to characterize and quantify the forces required for stent removal for future prototype testing.

METHODS

A custom 3-D urinary tract model was used for benchtop testing, and 6 female porcine subjects were used for in vivo testing after obtaining institutional approval. A modified porcine urethral model that patterned the human female urethral anatomy with approximately 4.5 cm urethral length was used. A HF-10 digital force gauge measured the force required to remove stents with varying properties (stent size, presence of curl, and size of distal magnetic bead). These force measurements were compared to the quantified magnetic forces generated by external magnets and catheter tip magnets. Furthermore, the magnetic retrieval devices were tested with various magnetic beads on both benchtop and porcine models.

RESULTS

The required force for removal of a 5 Fr x 14 cm double J stent was significantly higher in the benchtop model compared to the porcine model (4.7N v. 0.8N, p < 0.001). Forces of at least 1N were required from the external magnets to move the stent and bead across a 4-5 cm distance from the bladder neck to the urethral meatus. External magnets at a distance of 4-5 cm produced insufficient forces for removal, and thus they failed to remove the magnetic bead and stent from the bladder. The catheter-based retrieval device showed better success with a variety of different magnet pairs on the retrieval device and stent. Furthermore, the addition of saline to the bladder allowed for better retrieval rates of the smallest beads, even by the smallest magnetic tip catheters.

CONCLUSIONS

The forces required for ureteral stent removal are <1N in the porcine model, and improved benchtop models that emulate such parameters will facilitate future stent removal device testing. Given this threshold, external magnets did not generate sufficient force for stent removal at the required distance of 4-5 cm, whereas catheter tip magnetic retrieval overcomes the minimum distance limitation and showed successful retrieval. While these results are encouraging, further studies will define the optimal combination of catheter magnetic tip size and stent magnetic bead size.

Feasibility and safety of magnetic-end double-J ureteral stent insertion and removal in children

PURPOSE

The need for surgical removal of a double-J ureteral stent (DJUS) is considered one of its disadvantages. Apart from increased cost, repeated exposure to general anesthesia is a concern in children. Alternative techniques have been described, all failing to become integrated into mainstream practice. Stents with a distal magnetic end, although introduced in the early 1980s, have only recently gained acceptance. We report the feasibility and safety of insertion and removal of a magnetic-end double-J ureteral stent (MEDJUS) in a pediatric population.

MATERIALS AND METHODS

We retrospectively analyzed the use of the Magnetic Black-Star Urotech^® MEDJUS between 11/2016 and 12/2019 in children. Stents were removed in the outpatient clinic using a transurethral catheter with a magnetic tip.

RESULTS

MEDJUS insertion was attempted in 100 patients (65 boys). Mean age was 7.8 years (0.5-18). The stent was placed in an antegrade procedure (n = 47), by a retrograde route (n = 10), and during open surgery (n = 43). Stent insertion was successful in 84 cases (84%). All 16 failures occurred during the antegrade approach in laparoscopic pyeloplasty, with inability to push the stent and its magnet through the ureterovesical junction in 14. Magnetic removal was attempted in 83 patients, successful in 81 (98%). There was no added morbidity with the MEDJUS.

CONCLUSIONS

The use of MEDJUS is a safe and effective strategy that obviates the need for additional general anesthesia in children. Its insertion is similar to that with regular DJUS, and its easy and less time-consuming removal benefits both the patient and the hospital and validates its clinical use.