Ureteral Access Sheath Influence on the Ureteral Wall Evaluated by Cyclooxygenase-2 and Tumor Necrosis Factor-α in a Porcine Model

Surgical Force: Initial Study and Clinical Implications in the Assessment of Ureteral Access Sheath Induced Injury

Purpose: Ureteral access sheaths (UAS) pose the risk of severe ureteral injury. Our prior studies revealed forces ≤6 Newtons (N) prevent ureteral injury. Accordingly, we sought to define the force urologists and residents in training typically use when placing a UAS. Materials and Methods: Among urologists and urology residents attending two annual urological conferences in 2022, 121 individuals were recruited for the study. Participants inserted 12F, 14F, and 16F UAS into a male genitourinary model containing a concealed force sensor; they also provided demographic information. Analysis was completed using t-tests and Chi-square tests to identify group differences when passing a 16F sheath UAS. Participant traits associated with surpassing or remaining below a minimal force threshold were also explored through polychotomous logistic regression. Results: Participant force distributions were as follows: ≤4N (29%), >6N (45%), and >8N (32%). More years of practice were significantly associated with exerting >6N relative to forces between 4N and 6N; results for >8N relative to 4N and 8N were similar. Compared to high-volume ureteroscopists (those performing >20 ureteroscopies/month), physicians performing ≤20 ureteroscopies/month were significantly less likely to exert forces ≤4N (p = 0.017 and p = 0.041). Of those surpassing 6N and 8N, 15% and 18%, respectively, were high-volume ureteroscopists. Conclusions: Despite years of practice or volume of monthly ureteroscopic cases performed, most urologists failed to pass 16F access sheaths within the ideal range of 4N to 6N (74% of participants) or within a predefined safe range of 4N to 8N (61% of participants).

Postoperative Recovery of Quality-of-Life Following Ureteroscopy for Nephrolithiasis: The Impact on Pain Intensity and Interference and the Ability to Participate in Social Roles

OBJECTIVE

To prospectively capture patient-reported outcomes to assess the recovery profile of ureteroscopy (URS).

MATERIALS AND METHODS

Adults undergoing URS for renal/ureteral stones were eligible for inclusion (11/2020-8/2022). Patients prospectively completed PROMIS - Pain Intensity, - Pain Interference, and - Ability to participate in social roles and activities in-person preoperatively (POD 0) and via email on POD 1, 7, 14, and 30. Scores are reported as T-scores (normalized to U.S. population, mean=50) with a change of 5 (0.5 SD) considered clinically significant.

RESULTS

One hundred and seventy-eight participants enrolled at POD 0 (POD 1 =87, POD 7 =83, POD 14 =70, POD30 =67). There was a worsening of quality of life from day 0 to day 1 and day 0 to 7. All dimensions then improved with an increase in scores from day 0 to day 14 and day 0 to day 30. On multivariable analysis, the presence of a preoperative ureteral stent (OR 0.14) and use of semirigid URS (OR 0.33) were associated with a reduced odds for severe pain interference at day 1. The use of semirigid URS (OR 0.20) was associated with a reduced odds for severe worsening in the ability to participate in social roles at day 1.

CONCLUSION

Ability to participate in social roles declines immediately postoperatively, while pain intensity and interference sharply increase. There is a gradual improvement until POD 30. Findings suggest preoperative stents may influence postoperative recovery. Results offer meaningful insight to assist in counseling and setting expectation for patients postoperatively.

Does ureteral access sheath have an impact on ureteral injury?

Objective:

To present a well-organized review about ureteral access sheath impact on ureteral injury.

Materials and Methods:

Systemic search on literature was done. Total of 3766 studies observed by two urologists and results were unified. A Prisma diagram was used for eliminating irrelevant studies and at the end of elimination process 28 studies were found eligible for this review.

Results:

Not only clinical studies but also comparative experimental animal studies show that there is no significant data to claim that ureteral access sheath insertion causes more ureteral injury. Pre-stented patients were found to be at lower risk for ureteral injury. Risk of progression to ureteral injury seems to be low even if ureteral injury occurs with insertion of ureteral access sheath.

Conclusion:

Summary of studies’ results indicate that use of ureteral access sheath doesn’t increase ureteral injury. This review may help understanding safety profile of ureteral access sheath on evidence-based level. There is not enough data to make a statement that ureteral access sheath prevents ureteral injury.

Comparison of ureteroscopy (URS) complementary treatment after extracorporeal shock wave lithotripsy failure with primary URS lithotripsy with holmium laser treatment for proximal ureteral stones larger than10mm

Background

To compare ureteroscopy (URS) complementary treatment following extracorporeal shock wave lithotripsy (SWL) failure with primary URS lithotripsy for proximal ureteral stones > 10 mm, and try to find out acceptable number of SWL sessions followed by safe URS.

Methods

This was a retrospective study following approval from Medical Ethics Committee of People's Hospital of Chongqing Banan District. Patients (n = 340) who received URS in our hospital for stones > 10 mm from Jan 2015 to June 2020 were divided into two groups according to their previous SWL history. Group 1 consisted of 160 patients that underwent unsuccessful SWL before URS. Group 2 encompassed 180 patients without SWL before URS. Patient’s operative outcomes were compared. A logistic regression and receiver operator characteristics (ROC) were used to identify the acceptable number of SWL sessions prior to URS, regarding the intra-operative complications of URS.

Results

The group 1 required more surgery time (41.38 ± 11.39 min vs. 36.43 ± 13.36 min, p = 0.01). At the same time, more intra-operative (68.1% VS 22.8%, p < 0.05) and post-operative (35% VS 18.0%, p = 0.001) complications occurred in group 1. Need more hospital stay in group 1 (2.7 ± 1.2 days vs 1.6 ± 1.1 days, p < 0.05). More patients in group 1 need further URS (16.3% VS 8.9%, p = 0.029). After second URS, the SFR of URS in two groups was insignificant differences (82.5% VS 88.9%, p > 0.05). The median (25–75%) of SWL sessions before URS was 2 (1–3) in group 1. According to the results of logistic regression analysis, patients suffered more SWL failure have an increased risk of complications during URS (OR = 1.995, 95% CI: 1.636–2.434). ROC showed that the optimal number of SWL session followed by URS were 0.5, with a sensitivity of 67.7% and specificity of 71.5%. Intra-operative complication rates of URS treatment were higher in patients who suffered > 1 SWL failure (72.6% vs 57.4%, p = 0.047).

Conclusion

There was no acceptable number of SWL sessions that could be followed by URS with fewer intra-operative complications. Patients who underwent previous SWL were likely to suffer more intra-operative complications, the average operating time, hospitalization time, and needing further treatment, during URS treatment for proximal ureteral stones larger than 10 mm.

Evaluating predictive factor of Systemic Inflammatory Response Syndrome and Postoperative Pain in Patients Without Ureteral Stent Placement After Ureteral Access Sheath Use in Flexible Ureteroscopy for Stone Management

BACKGROUND AND OBJECTIVE

This retrospective cohort study aimed to evaluate the safety of stentless flexible ureteroscopy (fURS) using a ureteral access sheath (UAS) for stone management.

PATIENTS AND METHODS

A total of 270 ureteral stentless postoperative patients were analyzed. Stentless indication was characterized by having no ureteral wall or mucosa injury with only slight erosion, < 1-hour operative time, and no endoscopic stone fragments with or without stone dust. Postoperative complications and pain were analyzed for safety measurements. In addition, preoperative and intraoperative risk factors associated with the incidence of systemic inflammatory response syndrome (SIRS) and postoperative pain were evaluated.

RESULTS

The most common UAS sizes were 10/12 Fr (69.6%) and 9.5/11.5 Fr (28.1%). The rate of patients who were stone-free was 95.9%. The median operation time was 34 min. Only three grade 1 ureteral injuries occurred intraoperatively. Postoperative SIRS occurred in 8.8% of patients, and postoperative use of analgesics was 35.9%. Only four patients were required to undergo eventual ureteral stenting. Less than 10/12-Fr UAS was the only factor positively associated with preventing postoperative SIRS (odds ratio [OR], 4.733; 95% confidence interval [CI], 1.085-20.644). Older age and preoperative ureteral stenting were positively associated with preventing postoperative pain (OR, 0.970; 95% CI, 0.951-0.990 and OR, 0.427; 95% CI, 0.232-0.786; respectively).

CONCLUSION

Stentless fURS with UAS in stone management was feasible for selected patients. UAS size of < 10/12 Fr, older age, and preoperative stenting are possible keystones to achieving stentless fURS with UAS postoperatively.

Controversies associated with ureteral access sheath placement during ureteroscopy

The use of ureteral access sheaths (UAS) is common practice during routine flexible ureteroscopy procedures. However, debates and concerns continue amongst endourologists on routine UAS placement. UAS placement allows for multiple passages of the ureteroscope, decreases intrarenal pressure, and may improve stone-free rates. However, concerns for the UAS's effectiveness in these claimed benefits and complications related to UAS placement has been documented and investigated by many. In this review, we will discuss the controversies surrounding the placement of UAS during ureteroscopy.

Failure of ureteral access sheath insertion in virgin ureters: A retrospective tertiary care center study

Objective:

The objective of the study was to identify the failure rate of insertion of ureteral access sheath (UAS) during primary flexible ureteroscopy (FURS).

Materials and Methods:

This was a single-surgeon, single-tertiary care center retrospective study. All patients who underwent primary FURS for proximal ureteric or renal stones from November 2014 to May 2018 were included in the study. Patients with a stone burden of more than 20 mm were excluded from the study. A 10/12-Fr coaxial UAS (Bi-Flex, Rocamed) was used. Data collection included age, sex, body mass index (BMI), stone burden and location, previous spontaneous passage of stones, type of anesthesia, and preexisting congenital anomalies. The Chi-square test and t-test were used for the statistical analyses.

Results:

One hundred and twelve patients were included in the study. All patients underwent primary FURS. The failure rate of primary UAS insertion was 10.7% (n = 12). No statistically significant difference was found in age, BMI, type of anesthesia, previous history of spontaneous stone passage, and stone burden between the success and failure groups (P > 0.05).

Conclusions:

We believe that our study opens the door for a multicentric prospective trial. Identifying factors leading to a failed primary FURS and UAS insertion is crucial to properly counsel patients preoperatively about the number of procedures that they might need and to prevent the financial loss associated with failed UAS insertion.

Predictors of emergency department attendance following ureterorenoscopy for urolithiasis

BACKGROUND

We sought to determine the rate of emergency department (ED) attendance for complications after ureterorenoscopy (URS) for stone disease and to identify risk factors for ED attendance after URS.

METHODS

An analysis of all patients undergoing URS over 12 months at a single institution was performed. Patient demographics, preoperative and intraoperative variables associated with postoperative complications and subsequent ED attendance were collected. Logistic regression analyses were performed to determine predictors of URS complications presenting to ED.

RESULTS

In total, 202 ureteroscopies were performed on 142 patients for urolithiasis. The mean age was 50.73 ± 13.93 and 66% were male. The incidence of re-presentation to ED was 14.8% (n = 30). Patients presented with postoperative pain (n = 10; 4.95%), pyrexia (n = 9; 4.46%), urinary tract infection (UTI) (n = 7, 3.47%), haematuria (n = 3, 1.49%) and urosepsis (n = 1; 0.5%). Significant risk factors for ED attendance included preoperative stent dwell time > 30 days (P = 0.004), recently treated positive preoperative urine culture (P < 0.0001), stone size ≥ 13 mm (P = 0.043), stone location mid-ureter (P = 0.036) and female gender (P = 0.005). The following factors did not predict ED attendance, stent omission, access sheath utilization and operation duration.

CONCLUSION

Risk factors for ED attendance after URS include prolonged pre-stent dwell time, stone size ≥ 13 mm, treatment for a positive preoperative urine culture, mid-ureteric stone location and female gender. Urologists should be aware of these findings to decrease the risk of emergency re-presentation after elective URS surgery.

Practice patterns of ureteral access sheath during ureteroscopy for nephrolithiasis: a survey among endourologists worldwide

Background

The use of ureteral access sheath (UAS) during ureteroscopy is controversial. We aimed to explore practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists worldwide.

Methods

A 15-question survey was designed using the SurveyMonkey® platform. The questions covered the background and professional experience of the potential respondents, indications for UAS insertion, UAS caliber and possible complications associated with its use.

The questions were anonymously tabulated in order to determine practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists.

The survey was then distributed via e-mail to all the Endourological Society members.

Results

216 members responded. 99.53% of the respondents practice as endourologists, 63.4% are fellowship trained and 74.4% are at least 6 years post-fellow. 73.2% practice in an academic facility. 77.3% perform at least 100 ureteroscopies annually. 46 and 76% routinely use UAS for the treatment of ureteral and kidney stones, respectively. In both cases, the 12/14 access sheath is the most common. 42% use UAS in primary ureteroscopy. 90.3% believe that a double J stent insertion is not mandatory prior to UAS insertion. 79.1% think the use of UAS does not increase postoperative complications rate, and if the latter does encounter, then most likely it is either a ureteral stricture (93.2%) or pain (48%).

Conclusions

UAS is commonly used by highly skilled endourologists during ureteroscopy. 12/14 UAS is mostly used. Ureteral stricture and post-operative pain are proposed as possible complications following UAS introduction, however pre-stenting is not mandatory as overall low complication rate is expected.

Impact of previous SWL on ureterorenoscopy outcomes and optimal timing for ureterorenoscopy after SWL failure in proximal ureteral stones

PURPOSE

We aimed to evaluate the impact of previous unsuccessful shock wave lithotripsy (SWL) therapy on ureterorenoscopy (URS) outcomes in proximal ureteral stones and to define whether there is any optimal timing for safe URS after SWL.

METHODS

The patients who underwent URS for proximal ureteral stones between the years 2015 and 2018 in eight centers were included. Patients were divided into two groups according to previous SWL history; group 1 consisted of patients without SWL before URS for the stone [SWL (-)] and group 2 consisted of patients with a previous SWL for the stone [SWL (+)]. Demographics, operation outcomes and stone characteristics were compared between these two groups. Regarding the complication and success rates, optimal timing for URS after SWL for the stone was calculated with receiver operator characteristics curve analysis.

RESULTS

Totally 638 patients were included (group 1: 466 patients and group 2: 172 patients). The operation and hospitalization times, rate of ureteral stenting and complications were significantly higher in group 2. Stone free status was similar between the groups. Optimal timing for URS after SWL was calculated as 16.5 days (AUC = 0.657, p = 0.012) with a sensitivity of 68% and specificity of 72%, regarding the complication rates. Complication rates were significantly higher in patients who were operated before 16.5 days (27.7% vs 6.5%, p < 0.001).

CONCLUSIONS

The optimal timing; 2-3 weeks delay of the URS procedure after unsuccessful SWL may decrease complication rates according to our results.

Screening and isolation of cyclooxygenase-2 inhibitors from Trifolium pratense L. via ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography

Nonsteroidal anti-inflammatory drugs reportedly reduce the risk of developing cancer. One mechanism by which they reduce carcinogenesis involves the inhibition of the activity of cyclooxygenase-2, an enzyme that is overexpressed in various cancer tissues. Its overexpression increases cell proliferation and inhibits apoptosis. However, selected cyclooxygenase-2 inhibitors can also act through cyclooxygenase-independent mechanisms. In this study, using ultrafiltration, enzyme-immobilized magnetic beads, high-performance liquid chromatography, and electrospray-ionization mass spectrometry, several isoflavonoids in Trifolium pratense L. extracts were screened and identified. Semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography were then applied to separate the active constituents. Using these methods, seven major compounds were identified in Trifolium pratense L. As cyclooxygenase-2 inhibitors: rothindin, ononin, daidzein, trifoside, pseudobaptigenin, formononetin, and biochanin A, which were then isolated with >92% purity. This is the first report of the presence of potent cyclooxygenase-2 inhibitors in Trifolium pratense L. extracts. The results of this study demonstrate that the systematic isolation of bioactive components from Trifolium pratense L., by using ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography, and high-speed counter-current chromatography, represents a feasible and efficient technique that could be extended for the identification and isolation of other enzyme inhibitors.

Long-chain fatty acid-induced intracellular signaling in GPR120-expressing brush cells at the limiting ridge of the murine stomach

Brush cells at the gastric groove have been proposed to operate as sensory cells capable of sensing constituents of ingested food. Recent studies have indicated that these cells express GPR120 (also known as FFAR4), the G protein-coupled receptor for long-chain fatty acids (LCFAs). However, functional implications of this receptor in brush cells have remained elusive. Here, we show that a great proportion of brush cells express GPR120. We used phosphorylation of the extracellular signal-regulated kinases 1/2 (ERK1/2) as a readout to monitor brush cell responses to the LCFAs oleic acid and α-linolenic acid. Our results demonstrate that ERK1/2 phosphorylation is increased upon exposure to both fatty acids. Increased ERK1/2 phosphorylation is accompanied by upregulated mRNA and protein levels of cyclooxygenase 2 (COX-2), a key enzyme for prostaglandin biosynthesis. Immunohistochemical experiments confirmed that oleic acid caused ERK1/2 phosphorylation and induced COX-2 expression in brush cells. Our results indicate that LCFA sensing elicits a signaling process in brush cells that may be relevant for a local regulation of gastric functions.

Unplanned 30-Day Encounters After Ureterorenoscopy for Urolithiasis

OBJECTIVE

To identify avoidable predictors of postureteroscopy (URS) unplanned encounters and to minimize 30-day encounters.

MATERIALS AND METHODS

We performed retrospective chart review and telephone surveys on patients who underwent URS for urolithiasis between January and June 2016. Univariate and multivariable analyses evaluated for potential predictors of unplanned encounters.

RESULTS

Of 157 patients, there were 44 (28.0%) unplanned patient-initiated clinical phone calls, 23 (14.6%) emergency department (ED) visits, and 8 (5.1%) readmissions, with pain being the most common complaint during the encounters. Factors associated with a higher rate of phone calls include first-time stone procedure (36.6% vs 20.9%, p = 0.029), outpatient status (30.3% vs 0%, p = 0.021), intraoperative stent placement (31.2% vs 0%, p = 0.006), and stent removal at home (58.8% vs 28.8%, p = 0.014). Factors associated with increased rate of ED visits were first-time stone procedure (22.5% vs 8.1%, p = 0.011) and ureteral access sheath (UAS) usage (29.6% vs 11.8%, p = 0.018). Factors associated with a higher rate of readmissions were lower body mass index (23.9 vs 29.7, p = 0.013), bilateral procedure (20.0% vs 2.9%, p = 0.010), and UAS usage (14.8% vs 3.1%, p = 0.032). Stone burden, operative time, Charlson comorbidity index, and preoperative urinary tract infection were not significantly associated with postoperative encounters.

CONCLUSIONS

Pain, first-time stone treatment, presence of a ureteral stent, outpatient status, bilateral procedures, and UAS usage were common reasons for postoperative encounters after URS. Appropriate perioperative patient education and counseling and adequate pain management may minimize these encounters and improve treatment quality and patient satisfaction.

Systematic review of ureteral access sheaths: facts and myths

The aim of the present paper was to review the literature on all available ureteral access sheaths (UASs) with their indications, limitations, risks, advantages and disadvantages in current modern endourological practice. Two authors searched Medline, Scopus, Embase and Web of Science databases to identify studies on UASs published in English. No time period restriction was applied. All original articles reporting outcomes or innovations were included. Additional articles identified through references lists were also included. Case reports, editorials, letters, review articles and meeting abstracts were excluded. A total of 754 abstracts were screened, 176 original articles were assessed for eligibility and 83 articles were included in the review. Based on a low level of evidence, UASs increase irrigation flow during flexible ureteroscopy and decrease intrapelvic pressure and probably infectious complications. Data were controversial and sparse on the impact of UASs on multiple reinsertions and withdrawals of a ureteroscope, stone-free rates, ureteroscope protection or damage, postoperative pain, risk of ureteral strictures, and also on its cost-effectiveness. Studies on the benefit of UASs in paediatrics and in patients with a coagulopathy were inconclusive. In the absence of good randomized data, the true impact of UASs on surgery outcome remains unclear. The present review may contribute to the evidence-based decision-making process at the individual patient level regarding whether or not a UAS should be used.

Use of the ureteral access sheath during ureteroscopy: A systematic review and meta-analysis

The debate still rages on for the usefulness of ureteral access sheath (UAS). Therefore, a meta-analysis to discuss the effects of applying UAS during ureteroscopy was performed. The protocol for the review is available on PROSPERO (CRD42017052327). A literature search was conducted up to November, 2017 using the Web of science, PUBMED, EMBASE and Cochrane Library. The quality of articles was assessed by the Jadad scale and Newcastle Ottawa Scale (NOS). Egger’s test and the trim-and-fill method were used to evaluate publication bias. Effect sizes were calculated by pooled odds ratio (ORs) and mean differences (MDs). Sensitivity analyses and subgroup analyses were performed to explore the origin of heterogeneity. Eight trials with a total of 3099 patients and 3127 procedures were identified. Results showed no significant difference in stone-free rate (SFR) (OR = 0.83, 95% CI 0.52–1.33, P = 0.45), intraoperative complications (OR = 1.16, 95% CI 0.81–7.69, P = 0.88), operative time (MD = 4.09, 95% CI -15.08–23.26, P = 0.68) and hospitalization duration (MD = -0.13, 95% CI -0.32–0.06, P = 0.18). However, the incidence of postoperative complications was higher in UAS group (OR = 1.46, 95% CI 1.06–2.00, P = 0.02). Evidence from meta-analysis indicated that the use of UAS during ureteroscopy did not manifest advantages. However, given the intrinsic restrictions of the quality of selected articles, more randomized controlled trials (RCTs) are warranted to update the findings of this analysis.

Risks of flexible ureterorenoscopy: pathophysiology and prevention

Currently, indications for flexible ureterorenoscopy (fURS) are expanding, mainly due to technological advancements. Although data from clinical series definitely presents fURS as a safe procedure, serious complications including sepsis and ureteral lesions do occur. These complications seem to be a result of the unique elements of fURS, ureteral access and irrigation, pushing normal upper urinary tract physiology into pathophysiological processes, including intrarenal/pyelo-veneous backflow and ureteral contractions, potentially resulting in septic, haemorrhagic and ureteral lesional complications. Knowledge on normal upper urinary tract physiology are crucial for understanding how these harmful effects of fURS may be avoided or minimized. The pathophysiology of intrarenal pressure increases and ureteral access will be discussed as a basis for understanding preventive measures. Role of antibiotics, ureteral access sheaths, safty guidewires, pain medication, prestenting and pharmacologic modulation of pyeloureteral dynamics are reviewed from a pathophysiological perspective.

Histopathological correlations to ureteral lesions visualized during ureteroscopy

Purpose

To correlate ureteral lesions visualized during ureteroscopy with histopathological findings.

Materials and methods

Ureteral access sheaths (UAS) sized 13/15 Fr. were inserted bilaterally in 22 laboratory pigs. During retraction of the UAS with a semirigid ureteroscope inside, ureteral lesions were evaluated and registered using the Post-ureteroscopic lesion scale (PULS). Ureters were excised in vivo between the uretero–pelvic junction and the uretero–vesical junction. Embedded in paraffin, 4-µm thick sections were step sectioned at 250–300 µm intervals and haematoxylin and eosin (HE) stained. Histopathological scoring of ureteral wall lesions was subsequently performed according to PULS.

Results

In 72.1% of ureters, the highest histopathological score was at least 1 grade higher than the highest endoscopic PULS score. For 12 (27.9%) lesions, the difference was 2 scores higher, and for 1 (2.3%), it was 3 scores higher. The histopathological PULS grade was higher than the endoscopical PULS grade at all minimum, quartile, and maximum scores. There was a significant difference in the distribution of highest lesional scores between the endoscopic and histopathological PULS (p = 0.002). The calculated mean of the highest scores was 1.49 for endoscopic PULS and 2.51 for histopathological PULS (p < 0.0001).

Conclusion

Histopathological evaluation of ureteral wall lesions after UAS placement revealed a significantly higher degree of severity than observed endoscopically. Thus, endoscopy underestimated the histopathological extent of the lesion in the majority of cases.