Ureteral Stent Removal Research Articles

Double J Ureteral stent removal in children non cystoscopically: A preferred innovation.

Objective: To determine the feasibility of non cystoscopic removal of double J ureteral (DJ) stent using a foley catheter with suture in children in terms of success rate, number of attempts required and complications. Study Design: Cross Sectional study. Setting: Department of Pediatric Surgery, Services Hospital, Lahore. Period: August 2022 to August 2023. Methods: All the children who underwent DJ stent placement for any urological procedure were included if DJ stent was seen in the bladder postoperatively. After informed consent, under sedation and aseptic measures, the foley catheter with suture already passed through its eye, was introduced per urethral after adequate lubrication. The foley was given five to six rotations in clockwise direction for right sided and anti-clockwise for left sided stents respectively and pulled out keeping traction on the suture. In case of three failed attempts, a cystoscope was introduced under general anesthesia and the stent was removed. Successful removal, number of attempts needed, time taken, and post removal complications were noted to determine feasibility of the procedure. Results: Out of twenty patients, 17 patients (85%) underwent successful removal of DJ stent. The failure rate was 15% as three patients required cystoscope assisted removal. In 13 patients (76.5%) DJ stent was removed in first attempt, whereas in 4(23.5%) patients it required two attempts. Mean time taken was 8.83±7.33 minutes. Complications were noted in 2 patients (10%). Conclusion: Removal of DJ stent in children without cystoscope, using a foley catheter with suture is a safe and feasible procedure with a high success rate and should be attempted in selected cases.

Evaluation of a Ureteral Stent Removal Protocol in Adult Kidney Transplant Recipients.

Existing literature on best practices to reduce the risk of infectious complications associated with ureteral stent removal in kidney transplant recipients is limited. Prior to 2021, a formal process surrounding stent removal was not in place at our institution. In June 2021, a stent removal protocol was established. This protocol included the following: obtaining a preprocedure urine culture, prescribing universal culture-directed antimicrobial prophylaxis, earlier stent removal posttransplant, and patient education. We performed a retrospective quasi-experimental study of kidney transplant recipients who had their stents removed between July 2020 and June 2022. The primary outcome was the incidence of infectious complications within 30 days. Infectious complications were defined as urinary tract infection and bacteremia due to urinary source, as well as hospitalization, emergency department visit, or outpatient encounter for possible urinary tract infection. Secondary objectives included infectious and immunologic complications within 30 days to 1 year from transplant. During this study period, 239 adult kidney transplant recipients were included: 88 in the preprotocol group and 151 in the protocol group. The median time to stent removal was shorter in the protocol group (25 vs 36 days, P < .001). More patients in the protocol group received preprocedure antibiotics (99% vs 36%, P < .001). Infectious complications were higher in the preprotocol group (9% vs 3%, P = .035). Overall, the stent removal protocol was associated with fewer infectious complications (odds ratio, 0.18; 95% CI, 0.05-0.73). Further investigation is necessary to determine which individual interventions, if any, drive this benefit.

The Optimal Suture Bite Depth in Laparoscopic Pyeloplasty: A Comparative Study in Children.

Background: Modified Anderson-Hynes pyeloplasty is currently preferred for ureteropelvic junction obstruction (UPJO). Extravasation of urine and anastomotic stenosis are the most common complications after Anderson-Hynes pyeloplasty, which are closely linked with the technique for anastomosis. However, there are currently no clear guidelines for the suture bite depth in suturing the anastomosis during pyeloplasty. Objective: To analyze the optimal suture bite depth in laparoscopic Anderson-Hynes pyeloplasty. Study Design: A total of 90 children aged 4-14 years with UPJO-induced hydronephrosis who were surgically treated in the First People's Hospital of Lianyungang from July 2019 to July 2022 were prospectively recruited. All received laparoscopic Anderson-Hynes pyeloplasty using 5-0 Vicryl continuous sutures. According to the suture bite depth, the patients were divided into group A (depth 1 mm, n = 46) and group B (depth 0.5 mm, n = 44). Operation time, postoperative drainage volume, time of ureteral stent removal, incidence of postoperative complications, and time to hydronephrosis resolution were compared between groups. Results: Group A showed significantly less postoperative drainage volume, and shorter time of ureteral stent removal and hydronephrosis resolution (all P < .05). Four cases in group B received replacement of a double-J stent. Except for 1 patient receiving reoperation for anastomotic stenosis caused by massive extravasation of urine, the replaced double-J stent was successfully removed from the remaining 3 patients at 3 months, and the symptoms of anastomotic stenosis disappeared. No significant difference was detected in the operation time between groups (P > .05). Conclusion: An appropriate deeper suture bite depth for anastomosis may reduce postoperative urine extravasation and related complications in children who received laparoscopic pyeloplasty for UPJO-induced hydronephrosis.

657 Transplant Ureteric Stent Removal Using Isiris® in an Outpatient Setting

Abstract Aim The risk of urological complications following kidney transplantation is reduced by the intraoperative insertion of ureteric stents. Transplant ureteric stent removal (TUSR) has traditionally been performed in theatre using flexible cystoscopy. Isiris® is a single-use flexible cystoscope. The aim is to analyse the acceptability, efficacy, and cost-effectiveness of Isiris®, for TUSR in a ward/outpatient setting. Method A retrospective analysis of a contemporaneously maintained database at a high-volume kidney transplant centre from January 2021 to June 2022. Data collected included clinico-demographic, operative and stent removal details including time to removal (gold-standard within 6 weeks) and refusal rates. A cost analysis was also performed based on equipment costs and NHS tariffs. TUSR was performed using Isiris® in outpatient ANP-led clinics or on wards by surgical middle grades or ANPs. Results 345 patients were included in analysis with a median age of 54 (19-81). 99.13% were single ureteric anastamoses with 348 stents removed in total. The M:F ratio was 1.32:1. 98.85% of stents were removed using Isiris®, with a 1.15% refusal rate. 86.34% (n=297) were removed in clinic. Median dwell-time was 34 days, IQR 17.25 (25.75-43). 73.84% of stent removal was within 6 weeks. There were savings of £545.00 per stent removal, including expenses for failed Isiris TUSR, with overall savings of £154,021.20 and 86 theatre sessions freed for other activity. Conclusions Isiris® was acceptable and effective for TUSR. Savings were demonstrated compared to TUSR in theatre. Outpatient/ward TUSR reduces demand for theatre time, freeing theatres for other elective activities.

Urological Challenges during Pregnancy: Current Status and Future Perspective on Ureteric Stent Encrustation.

The management of ureter hydronephrosis and urolithiasis during pregnancy has been changed by the adoption of ureteric stents. Despite their broad use for several other conditions, from emergency to elective settings, their complications cannot be ignored. Being most prevalent during pregnancy, urinary tract infections and stent encrustations are particularly common and can affect either fetal growth or maternal-fetal homeostasis, leading to obstetric complications. The main concern associated with ureteric stents is the indwelling time, which could represent the potential trigger of those complications. However, to ensure the optimal management of a ureteric stent during pregnancy, factors such as the grading of encrustations and the presence, size, and location of stones should be evaluated in pre-operative planning. As a consequence, a multimodal approach, including obstetrics, gynecologists, urologists, and nurses, is essential to ensure a complication-free procedure and successful ureteric stent removal. Finally, future research should focus on utilizing biodegradable and biocompatible materials to reduce and even eliminate the complications related to forgotten stents in order to reduce the financial burden associated with stent replacement and the management of stent-encrustation-related complications.

MAGnetic REtriaval Device for Minimally Invasive Ureter Stent Removal.

Purpose: To assess the effectiveness and pain intensity associated with magnetic ureteral stent removal using a retriever, without the aid of ultrasound guidance. Methods: We prospectively enrolled 100 patients who underwent retrograde rigid and flexible ureterorenoscopy with or without laser lithotripsy for ureteronephrolithiasis treatment from September 2021 to June 2023. These patients were assigned in two groups. Group 1 underwent the traditional ureteral stent insertion, while Group 2 underwent magnetic ureteral stent insertion. Both insertion and removal times were documented. The indwelling time for ureteral stents was 14 days. One group underwent stent removal via flexible cystoscopy using grasping forceps and the other group using just a magnetic retriever, without the aid of ultrasound guidance. The numeric pain rating scale, recommendation rate, and a standardized self-answered ureter stent symptoms questionnaire (USSQ) were obtained directly after stent removal. Results: Both groups presented comparable characteristics in factors such as age, body mass index, history of stone treatments, procedure type, and complication rates during and post-surgery. Time taken for ureteral stent insertion did not differ significantly between the groups (131.2 seconds for Group 1 vs 159.1 seconds for Group 2). However, the stent removal time (152.1 seconds for Group 1 vs 35.4 seconds for Group 2) and pain intensity (6 for Group 1 vs 2 for Group 2) were significantly lower for Group 2. Furthermore, five out of the six sections of the USSQ showed significantly better results for Group 2. Conclusions: The use of magnetic ureteral stents, as a safe and efficient alternative to conventional ureteral stents, not only eliminates the need for cystoscopy but also conserves resources and reduces patient discomfort.

Disposable grasper-integrated flexible cystoscope for ureteral stent removal in transplanted patients; focus on feasibility, safety, and patient experience. Results and micro-cost analysis from a tertiary referral center.

To evaluate ureteral stent removal (SR) using a grasper-integrated disposable flexible cystoscope (giFC-Isiris ®, Coloplast ®) after kidney transplantation (KT), with a focus on feasibility, safety, patient experience, and costs. All consecutive KT undergoing SR through giFC were prospectively enrolled from January 2020 to June 2023. Patient characteristics, KT and SR details, urine culture results, antimicrobial prescriptions, and the incidence of urinary tract infections (UTI) within 1 month were recorded. A micro-cost analysis was conducted, making a comparison with the costs of SR with a reusable FC and grasper. A total of 136 KT patients were enrolled, including both single and double KT, with 148 stents removed in total. The median indwelling time was 34 days [26, 47]. SR was successfully performed in all cases. The median preparation and procedure times were 4 min [3,5]. and 45 s[30, 60], respectively. The median Visual Analog Scale (VAS) score was 3 [1, 5], and 98.2% of patients expressed willingness to undergo the procedure again. Only one episode of UTI involving the graft (0.7%) was recorded. Overall, the estimated cost per SR procedure with Isiris ® and the reusable FC was 289.2€ and 151,4€, respectively. This prospective series evaluated the use of Isiris ® for SR in a cohort of KT patients, demonstrating feasibility and high tolerance. The UTI incidence was0.7% within 1 month. Based on the micro-cost analysis, estimated cost per procedure favored the reusable FC.

Technical feasibility and safety of the alternative snare technique using a 0.018-inch guide wire and 5-French catheter for double-J ureteral stent removal.

To evaluate the technical feasibility of the alternative snare technique using a 0.018-inch guide wire and 5-French (Fr) catheter for double-J ureteral stent (DJUS) removal. In this retrospective study, 11 DJUS were removed in 9 consecutive patients between July 2023 and October 2023. We evaluated patient characteristics, DJUS characteristics, and procedure characteristics. Out of 11 cases, 8 (72.7%) were successful in removing the DJUS using the alternative snare technique without major complications. The average time between DJUS insertion and removal was 47.4 ± 50.0 days. The most common DJUS size was an 8-Fr, with proximal tips predominantly in the proximal ureter and renal pelvis. The mean procedure time for successful cases was 15.2 ± 16.8 minutes. Three failed cases, attributed to obstructions like debris, were later successfully addressed using the ALN inferior vena cava filter removal kit, forceps, and modified snare technique. The alternative snare technique using a 0.018-inch guidewire and Fr catheter is safe and effective in cases of DJUS removal.

Routine Kidney Graft Ultrasound After Elective Ureteric Stent Removal: Does it Help?

Transplantation (KTx) is considered to be the best renal replacement therapy, and improving its outcomes remains a primary challenge. KTx ureteral stenting has been used to prevent urological complications, but there is no consensus on the timing of stent removal, and literature regarding routine ultrasonography after ureteric stent removal (RUSUS) to detect complications is lacking. Point-of-care ultrasound has been gaining drive in the medical community in recent years, including nephrologists. We aimed to define the incidence of urological complications diagnosed with RUSUS, if those findings changed patient's management and ultrasound utility. Contrary to previously published data, in our cohort RUSUS allowed a timely diagnosis and early treatment of urological complications, a key factor for successful transplantation. KTx point-of-care ultrasound is a cost-effective and reproducible test that provides relevant information to guide clinical decisions, seeming most efficient when performed approximately 2 weeks post ureteral stent removal. Interventional nephrologists can promptly perform these examinations, reducing waiting times and improving graft and patient's survival.

The effect of informative video before the procedure on anxiety levels in patients who will have ureteral stent removal under local anesthesia

ObjectiveOur objective was to assess the impact of video-animated information on the anxiety levels of patients undergoing ureteral stent removal under local anesthesia. MethodThe study was designed as a randomized prospective trial. The one group received only verbal and written information before the surgery, while the other group received video-animated information in addition to the written and verbal instructions. The patients’ anxiety levels were assessed using the STAI-S and STAI-T questionnaires, while their pain scores were evaluated using VAS scores. Tolerability and satisfaction scores were also evaluated on a 5-point Likert scale. ResultsThe video-group (Group 1) consisted of 74 patients, while the non-video group (Group 2) consisted of 82 patients. The mean pre-information STAI-T score was 34.4 ± 3.7 in Group 1 and 35.2 ± 3 in the Group 2 (p = 0.113). In the video group, pre-information STAI-S scores was 34.8 ± 3.3 and post-information STAI-S scores was 33.8 ± 3 (p < 0.001). In the non-video group, pre-information STAI-S score was 35.6 ± 2.6 and post-information STAI-S score was 35.5 ± 2.7 (p = 0.260). The mean VAS score of Group 1 is 5.7 ± 1.2 and Group 2 is 5.7 ± 1.4 (p = 0.608). The mean tolerability scores of Group 1 and Group 2 were 3.7 ± 0.9 and 2.7 ± 1, respectively. The mean satisfaction scores of Group 1 and Group 2 were 4.1 ± 0.9 and 2.6 ± 1, respectively. Both tolerability score and satisfaction score improved statistically significantly after video information (p < 0.001). ConclusionProviding video-animated information in addition to written and verbal information before removing the ureteral stent reduces patients’ preoperative anxiety. Furthermore, patient tolerance and satisfaction are higher when informative videos are included.

Urology never events in the United Kingdom: A retrospective 10‐year review

AbstractObjectivesThe aim was to assess the prevalence of never events (NEs) specific to urology in the United Kingdom and identify commonly occurring themes.MethodsData from the National Health Service (NHS) NEs website were obtained and all NEs from 2012 to 2022 were reviewed. Urology‐specific NEs were identified and further analysed in their respective categories. Data regarding the total number of surgical procedures performed in the NHS specific to each specialty were obtained via the NHS Hospital Episode Statistics website.ResultsThere were 3972 NEs recorded over the 10‐year period with 95 (2.4%) of these as a result of urology surgery. The most common surgical intervention associated with a urological NE was ureteric stenting, which comprised 45/95 (47.4%) of all analysed NEs. These consisted of wrong site ureteric stent insertion (n = 29), wrong site ureteric stent removal (n = 9), wrong stent type (n = 5) and retained guidewires (n = 2). There were 7.14 million urology surgeries performed in the 10‐year period, and prevalence was 0.0013%.ConclusionNEs are fully preventable serious incidents in the NHS. This is the first study to investigate the prevalence of NEs in urology in the United Kingdom. This study demonstrates that in the last 10 years the prevalence of urology NEs is low at 0.0013%, with ureteric stent procedures accounting for more than half of the NEs. Urologists should be mindful of the potential for wrong site surgery in urologic stenting procedures.

El efecto del vídeo informativo preoperatorio sobre los niveles de ansiedad en pacientes que serán intervenidos para extracción del stent ureteral bajo anestesia local

ObjectiveOur objective was to assess the impact of video-animated information on the anxiety levels of patients undergoing ureteral stent removal under local anesthesia. MethodThe study was designed as a randomized prospective trial. The one group received only verbal and written information before the surgery, while the other group received video-animated information in addition to the written and verbal instructions. The patients’ anxiety levels were assessed using the STAI-S and STAI-T questionnaires, while their pain scores were evaluated using VAS scores. Tolerability and satisfaction scores were also evaluated on a 5-point likert scale. ResultsThe video-group (Group 1) consisted of 74 patients, while the non-video group (Group 2) consisted of 82 patients. The mean pre-information STAI-T score was 34.4±3.7 in Group 1 and 35.2±3 in the Group 2 (p=0.113). In the video group, pre-information STAI-S scores was 34.8±3.3 and post-information STAI-S scores was 33.8±3 (p<0.001). In the non-video group, pre-information STAI-S score was 35.6±2.6 and post-information STAI-S score was 35.5±2.7 (p=0.260). The mean VAS score of Group 1 is 5.7±1.2 and Group 2 is 5.7±1.4 (p=0.608). The mean tolerability scores of Group 1 and Group 2 were 3.7±0.9 and 2.7±1, respectively. The mean satisfaction scores of Group 1 and Group 2 were 4.1±0.9 and 2.6±1, respectively. Both tolerability score and satisfaction score improved statistically significantly after video information (p<0.001). ConclusionProviding video-animated information in addition to written and verbal information before removing the ureteral stent reduces patients’ preoperative anxiety. Furthermore, patient tolerance and satisfaction are higher when informative videos are included.

Single-use digital flexible cystoscope for double J removal versus reusable instruments: a prospective, comparative study of functionality, risk of infection, and costs

BackgroundThe removal of ureteral stent can be performed with disposable or reusable flexible cystoscopes, but limited comparative data are available on functionality, risk of infections, and costs.MethodsWe performed a multicentric, prospective, observational study on patients undergoing in-office ureteral stent removal with Isiris-α® or a reusable Storz™ flexible cystoscope. Study endpoints were the functionality and effectiveness of the devices, the rate of postoperative bacteriuria and UTIs, and the costs of the procedure.ResultsA total of 135 patients were included, 80 (59.2%) treated with reusable cystoscopes and 55 (40.8%) with Isiris-α®. No significant baseline differences between groups were detected. Isiris-α® outperformed the reusable device in terms of quality of vision (p 0.001), manoeuvrability (p 0.001), grasper functionality (p < 0.001), and quality of the procedure (p 0.01). Mean procedure time was shorter with Isiris-α® (p < 0.001) due to a shorter instrument preparation time (p < 0.001). No differences were found in terms of perceived patient pain (p 0.34), nor postoperative bacteriuria or symptomatic UTIs. According to our cost analysis, the in-office procedure performed with Isiris-α® was more expensive (+ 137.8€) but was independent from instrument turnover or disinfection. Among limitations of study we acknowledge the lack of randomization, the use of antibiotic prophylaxis in several patients, and the high rate of missing preoperative urine cultures.ConclusionsIsiris-α® outperforms reusable cystoscopes for in-office ureteral stent removal in terms of total operative time and quality of the procedure, at the cost of being more expensive. No significant differences in postoperative bacteriuria or symptomatic UTIs were found.

3D Laparoscopic Ureterolysis for Retroperitoneal Fibrosis Secondary to Radical Hysterectomy and Radiation Treatment for Cervical Cancer: Results from the Oncological Institute, Cluj Napoca.

Ureterolysis represents the surgical treatment for retroperitoneal fibrosis. The aim of the study was to review the outcomes of patients who had undergone radical hysterectomy and radiotherapy for cervical cancer that later developed retroperitoneal fibrosis, for whom 3D laparoscopic ureterolysis was performed in our department and to review current published studies. We present a series of cases consisting of 6 patients with secondary retroperitoneal fibrosis. In all cases, the intervention was performed by the same surgeon from the Oncological Institute "Prof. Dr. Ion Chiricuță" Cluj-Napoca, Romania. We carried out a literature review, searching in the PubMed and MEDLINE studies published between 2000 and 2021 relevant to the matter and a total of 12 papers were selected. We reviewed the functional outcomes of patients that underwent minimally invasive ureterolysis. 3D laparoscopic ureterolysis was performed in 6 patients. Mean operative time was 166 minutes and mean blood loss was 203 mL. No surgery required conversion. Five patients showed good functional results after ureteral stent removal. In one case, the patient developed acute pyelonephritis and the ureteral stents were kept. Laparoscopic ureterolysis for retroperitoneal fibrosis secondary to operated and radiation-treated cervical cancer represents one of the most complex and challenging surgeries in the urological field. From personal experience we conclude that in oncological centers with vast experience in laparoscopy this minimally invasive approach is feasible and safe. Published data, even though scarce, strengthens our results and the need for this surgery in patients with retroperitoneal fibrosis with urological impact. The laparoscopic approach comes with good functional results and with the advantages of faster post-operative recovery comparing to open surgery and comparable results with the precision and dexterity offered by the robotic approach, but with lower economic burden.

Prospective Randomized Trial of Single-Use vs Reusable Cystoscope for Ureteral Stent Removal.

Background: Reusable cystoscopes are associated with risks of cross-contamination, need for chemical reprocessing, mechanical breakdown, maintenance costs, and labor for cleaning. A sterile, single-use cystoscope may reduce or eliminate the source of these infections while also decreasing exposure to reprocessing chemical agents. In this multicenter, randomized trial, we sought to compare single use with reusable endoscopes for ureteral stent removal. Methods: A three-center, randomized, dual-arm postmarket clinical trial was performed to compare the single-use cystoscope (Ambu A/S) with standard-of-care flexible reusable cystoscopes for outpatient ureteral stent removal. A total of 102 patients were randomized and evaluated from baseline through day 10 postprocedure. Primary endpoint was successful stent removal. Secondary endpoints were time from preparation to disposal/reprocessing, adverse events (AEs), and clinician satisfaction. Results: A total of 102 subjects were randomized in a 1:1 manner. The successful stent removal rate was 51/51 (reusable) and 50/51 (single use). One patient required the conversion to reusable cystoscope owing to grasper passage issue. Median time from prep for the procedure to disposal/prep for reprocessing was 10.2 minutes for the single use and 18.4 minutes for the reusable (p < 0.001). There was no difference in clinician satisfaction between both arms. There was no difference in AEs between arms and no device causal attribution for any AE reports. There was one serious AE necessitating hospitalization for infection in the reusable arm. Conclusion: The randomized-controlled trial of single-use cystoscopes vs reusables showed comparable device success with significant time savings for single use and equivalent clinician satisfaction. The study was registered on clinicaltrials.gov database (NCT04829461) on April 2, 2021.

Safety and effectiveness of magnetic ureteric stent removal under ultrasound control: a randomized single center trial.

To assess the safety and effectiveness of magnetic ureteric stent removal with a special magnet retriever under ultrasound guidance. A total of 60 male patients, who underwent ureteroscopy from October 2020 to March 2022, were prospectively enrolled and randomized into two groups. Group A patients underwent conventional double-J (DJ) stent insertion and subsequent stent removal via flexible cystoscopy. Group B patients underwent stent insertion using magnetic ureteric stent [Blackstar, Urotech (Achenmühle, Germany)] and stents were removed using a special magnet retriever under ultrasound guidance. Stents were left in situ for 30days in both groups. All patients had follow-ups with a ureter stent symptoms questionnaire at 3- and 30-days post stent insertion. Visual analog scale (VAS) was assessed immediately after stent removal. Stent removal time (142.5s vs 142.5s, group A vs group B, p < 0.0001) and VAS scores (4 vs 1, group A vs group B, p = 0.0008) were significantly lower in Group B. There were no statistically significant differences between both groups in the "urinary symptoms" (p = 0.3471) and "sexual matters" (p = 0.6126) in the USSQ domains. There was marginal statistical significance favoring Group A in the "body pain" (p = 0.0303), "general health score" (p = 0.0072), "additional problems" (p = 0.0142), and "work performance" (p < 0.0001) domains. Magnetic ureteric stent can be considered as a safe and efficient alternative to conventional DJ stent. This approach avoids the need for cystoscopy, saving resources while minimizing patient discomfort.

Recanalize ureteral stents with focused ultrasound.

Maintaining ureteral patency is imperative to preventing renal injury and systemic infection. Ureteral stents are small conduits connecting the kidney and the bladder. They have been widely used to treat ureteral obstructions and ureteral leaks. The most problematic and frequent stent-associated complication is stent encrustation. This occurs when mineral crystals (e.g. calcium, oxalate, phosphorus, struvite) are deposited onto the surface and internal lumen of the stent. Encrustation can lead to the obstruction of a stent and increases risk of systemic infection. As a result, ureteral stents need to be replaced typically every 2-3 months. In this study, we present a non-invasive, high-intensity focused ultrasound (HIFU)-based technique to recanalize obstructed stents. By taking advantage of the mechanical force produced by a HIFU beam, including acoustic radiation force, acoustic streaming, and cavitation, HIFU can break up encrustations, clearing the stent of obstruction. The ureteral stents for this study were obtained from patients undergoing ureteral stent removal. Under the guidance of ultrasound imaging, the encrustation in the stents were located, and then targeted by HIFU at frequencies of 0.25 and 1MHz. The duty cycle of HIFU was 10%, and the HIFU burst repetition rate was 1Hz, while the HIFU amplitude was varied to find the threshold pressure that would displace encrustations. The treatment duration was limited at 2 min (or 120 shots from HIFU). The treatments were carried out in two different orientations (parallel and perpendicular) of the ureteral stent with respect to the HIFU beam. For each setting, five treatments were conducted for a maximum duration of 2 min. During the entire treatment, an ultrasound imaging system was used to monitor the movement of encrustations inside the stent. The peak negative HIFU pressures needed to move the encrustations inside the stent was recorded for quantitative analysis. Our results demonstrated that at both 0.25 and 1MHz ultrasound frequencies, obstructed stents could be recanalized. At 0.25MHz, the needed average peak negative pressure was 0.52MPa in parallel orientation and 0.42MPa in perpendicular orientation. At 1MHz, the needed average peak negative pressure was 1.10MPa in parallel orientation and 1.15MPa in perpendicular orientation CONCLUSIONS: This first in-vitro study has demonstrated the feasibility of non-invasive HIFU to recanalize ureteral stents. This technology has a potential to reduce the need for ureteral stent exchange.

Patients’ Experiences With the Removal of a Ureteral Stent: Insights From In-depth Interviews With Participants in the USDRN STENTS Qualitative Cohort Study

To describe the experiences of patients undergoing stent removal in the USDRN Study to Enhance Understanding of Stent-Associated Symptoms (STENTS), a prospective, observational cohort study of patients with short-term ureteral stent placement post-ureteroscopy. We conducted a qualitative descriptive study using in-depth interviews. Participants reflected on (1) painful or bothersome aspects of stent removal, (2) symptoms immediately after removal, and (3) symptoms in the days following removal. Interviews were audio-recorded, transcribed, and analyzed using applied thematic analysis. The 38 participants interviewed were aged 13-77 years, 55% female, and 95% White. Interviews were conducted 7-30 days after stent removal. Almost all participants (n = 31) described that they experienced either pain or discomfort during stent removal, but for most (n = 25) pain was of short duration. Many participants (n = 21) described anticipatory anxiety related to the procedure, and several (n = 11) discussed discomfort arising from lack of privacy or feeling exposed. Interactions with medical providers often helped put participants at ease, but also increased discomfort for some. Following stent removal, several participants described lingering pain and/or urinary symptoms, but these largely resolved within 24hours. A few participants described symptoms persisting for more than a day post stent removal. These findings on patients' experiences during and shortly after ureteral stent removal, particularly the psychological distress they experienced, identify opportunities for improvement in patient care. Clear communication from providers about what to expect with the removal procedure, and the possibility of delayed pain, may help patients adapt to discomfort.

A randomized controlled study of ureteral stent extraction string on patient’s quality of life and stent-related complications after percutaneous nephrolithotomy in the prone position

To demonstrate the Tianjin Institute of Urology (TJIU) technique to place and remove the ureteral stent with extraction string after percutaneous nephrolithotomy (PCNL). Additionally, we aim to compare the pain experienced during stent removal, quality of life during stent retention, and stent-related complications between patients with and without extraction string. 65 patients were included in the final analysis in the string group constructed by the TJIU technique and 66 patients in the conventional double-J ureteral stent (non-string) group. All patients underwent the surgery in a prone position under general anesthesia. They completed the Ureteral Stent Symptom Questionnaire (USSQ) on postoperative days (POD) 7, as well as before their ureteral stent was removed. The visual analogue scale (VAS) pain score (0–10) was completed immediately after the removal of the ureteral stent. Moreover, a specialized person was responsible for recording stent-related complications. All patients completed the USSQ on POD 7, and we did not find a difference in scores in each field. However, there was a significant difference in the “sex” domain before removing the ureteral stent (4.34 vs 3.23; p = 0.01). Notably, the use of extraction string after PCNL could decrease the pain associated with stent removal significantly (mean VAS scores 1.45 vs 2.76; p < 0.01). Extraction string did not increase the incidence of stent-related complications. We concluded that placing a ureteral stent with an extraction string after PCNL reduces the pain of ureteral stent removal without increasing complications such as accidental removal of the stent, febrile urinary tract infection (UTI).

Posterior Spinal Cord Infarct: To Make the Diagnosis, Think of the Unthinkable! (P12-5.004)

<h3>Objective:</h3> We report a case of posterior spinal artery (PSA) infarct initially misdiagnosed as transverse myelitis (TM) and highlight some of the differentiating features of this exceedingly rare entity. <h3>Background:</h3> Spinal cord infarcts (SCIs) represent 1% of strokes and 5–8% of acute myelopathy. In a systematic review of 133 cases of SCI collected over two decades, PSAs presented 11% of the total pool. Redundancy in the vascular supply of the posterior portion of the spinal cord accounts for PSA rarity. <h3>Design/Methods:</h3> A single case report. <h3>Results:</h3> A 62-year-old woman with a history of recurrent nephrolithiasis, vitamin B12 deficiency, hypertension, and hyperlipidemia presented painless and rapidly progressive severe numbness and weakness of the legs. Sphincter symptoms were absent. Enhanced Magnetic Resonance Imaging (MRI) of the brain and spinal cord were unremarkable. Cerebral spinal fluid (CSF) was unremarkable. She was diagnosed with TM, given a five-day course of intravenous (IV) steroids, and discharged to a rehabilitation facility with a protracted and incomplete recovery. She presented two years later with fluctuating sensory and motor symptoms in the context of ureteral stent removal. Repeat CSF was unremarkable. However, on repeat thoracic spine MRI, there was interval development of a T2 hyperintensity along the dorsal columns and myelomalacia from T3–T4 disc to T12. She received IV steroids with minimal improvement. She had recurrent myelopathy pseudoexacerbations in the context of concurrent illnesses subsequently. Spinal magnetic resonance angiography, computerized chest, abdomen, pelvis tomography, positron emission tomography scan, and cardiovascular investigations were unremarkable. <h3>Conclusions:</h3> Given its scarcity, PSA infarct can often go misdiagnosed. A high index of suspicion for PSA should be kept in mind, particularly in the case of 1) acute, severe, and rapidly progressive myelopathic symptoms, 2) an extensively normal CSF analysis, and 3) an initially normal MRI of the spinal cord that eventually shows some T2 hyperintensity and cord atrophy. <b>Disclosure:</b> Dr. Solis has nothing to disclose. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bayer. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Celgene/BMS. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genzyme. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merck Serono. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Teva Neurosciences. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving as a Consultant for TG Therapeutics. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Teva. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Genentech. Dr. Zabad has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for BMS. The institution of Dr. Zabad has received research support from Adamas. The institution of Dr. Zabad has received research support from Biogen. The institution of Dr. Zabad has received research support from Novartis. The institution of Dr. Zabad has received research support from Sun Pharma. The institution of Dr. Zabad has received research support from Parexel &amp; MedDay Pharmaceuticals.