Use of Ureteral Stent in Extracorporeal Shock Wave Lithotripsy for Upper Urinary Calculi: A Systematic Review and Meta-Analysis

Does preoperative silodosin administration facilitate ureteral dilatation during flexible ureterorenoscopy? A randomized clinical trial

PURPOSE

To assess whether preoperative administration of silodosin can facilitate the placement of ureteral access sheath (UAS) prior to flexible ureteroscopy (F-URS) and reduce the occurrence of ureteric injury in challenging cases.

METHODS

This prospective randomized clinical trial was carried out on 147 patients diagnosed with upper ureteric stone or stone kidney, non-stented. The patients were randomly divided into two equal groups. Group A (silodosin group) included patients in whom F-URS was done with daily preoperative intake of 8 mg silodosin for 1 week and group B (placebo/control group) included patients in whom F-URS was done with daily preoperative intake of placebo tablets.

RESULTS

In group A, a total of 23 (33.3%) experienced ureteral wall injury following UAS insertion, while in group B, this occurred in 40 patients (59.7%). There was a statistically significant difference in the grade of ureteral wall injury between the two groups (P < 0.001). In the multiple regression analysis, age, operative time and silodosin were found to be significant risk factors for ureteral wall injury (P = 0.007, 0.041 and < 0.001, respectively).

CONCLUSIONS

The administration of silodosin prior to retrograde intrarenal surgery (RIRS) effectively prevented significant ureteral wall damage and reduced initial postoperative discomfort.

Noncystoscopic Removal of Double-J Stent in Women: Feasibility and Safety

OBJECTIVE

To evaluate the feasibility and safety of a simple noncystoscopic method previously applied in children for removing double-J stents applied in women by comparing the hospitalization time, operation time, costs, complications, and success rate.

METHODS

One hundred eighty women who underwent either cystoscopic or noncystoscopic double-J stent removal in a randomized manner. They were randomly assigned 1:1 to groups of cystoscopic double-J stent removal (n = 90) or noncystoscopic double-J stent removal (n = 90). The age ranged from 19 to 72years. After the removal of the double-J stent, the operation time, costs, complications, and success rate were compared between the two groups.

RESULTS

The operation time of the noncystoscopic group was lower than that of the cystoscopic group (6.0(5.0,7.0) minutes vs 2.0(2.0,3.0) minutes, P < .001). The hospitalization costs of the noncystoscopic group were significantly shorter than that of the cystoscopic group (1361.2(1331.4,1379.2) Yuan vs 873.9(868.5,896.1) Yuan, P < .001). There were no complications such as infection and massive bleeding in the two groups during and after the operation. Most noncystoscopic double-J stent removal can succeed in less than three attempts (88/90). All patients in the noncystoscopic group used this technique to remove the double-J stent.

CONCLUSION

Noncystoscopic removal of double-J stent has the advantages of short operation time and low hospitalization costs. It is a safe and feasible minimally invasive method to replace cystoscopic removal of the double-J stent.

Efficacy and Safety of Extracorporeal Shock Wave Lithotripsy (ESWL) in Patients With Infected Ureterohydronephrosis Due to Ureteral Stones Following Double-J Catheter Insertion

INTRODUCTION

Double-J ureteral catheters in patients with ureteral lithiasis undergoing extracorporeal shockwave lithotripsy (ESWL) procedures reduce the efficacy of the procedure or have no effect on the stone-free rate. However, the effect of double-J catheters on the patients in whom they were inserted for infected hydronephrosis is not known. The aim of our study was to evaluate the efficacy and safety of the ESWL procedure in patients with ureteral lithiasis and double-J catheters previously inserted for infected hydronephrosis.

METHOD

We conducted a comparative case-control, match-paired study in a group of patients with ureteral lithiasis treated by ESWL from January 1, 2018, to March 1, 2023, who were divided into two groups according to the presence of the double-J catheter. For each patient with the double-J catheter from the study group, we selected one patient for the control group without the double-J catheter and matched them in terms of size, location of stones, and body mass index (BMI). We analyzed the stone-free rate and complications that occurred in the two groups.

RESULTS

Forty patients with ureteral lithiasis and a double-J catheter inserted for infected hydronephrosis were enrolled in the study group. The control group included 40 patients with ureteral stones without double-J catheters. The patients in the two groups were predominantly men with stones located in the lumbar region and on the right side and with a BMI between 25 and 30 kg/m2. The stones had an average size of 0.9+/-0.12mm and 0.89+/-0.15mm, respectively (p=0.624). There was no statistically significant difference in stone-free rate between the two groups after the first session of ESWL (47.5% vs. 52.5%, p=0.502), the second (70% vs. 75%, p = 0.616), and the third session (85% vs. 87.5%, p=0.761). The rate of complications was similar in both groups (7.5% vs. 5%, p=0.761).

CONCLUSIONS

The presence of double-J catheters inserted in patients with ureteral stones who underwent ESWL for infected hydronephrosis does not affect the stone-free rate of the procedure or the complication rate. The procedure of ESWL in patients with ureteral lithiasis and double-J catheters inserted for infected hydronephrosis is a safe and efficient method that can be recommended as an initial treatment alongside retrograde ureteroscopy.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

2022 Recommendations of the AFU Lithiasis Committee: Extracorporeal shock wave lithotripsy (ESWL)

Extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive technique for the fragmentation of urinary tract stones using shock waves under fluoroscopic and/or ultrasound guidance. ESWL results depend on the indication (stone size/composition, clinical context) and also on how it is performed. The stone structure, nature and density (Hounsfield units; evaluated by CT without contrast agent) influence the fragmentation achieved by ESWL. The upper size limit of kidney stones has been lowered to 15mm (1.68cm3) due to the increased risk of steinstrasse with larger sizes and the potential need of anesthesia and ureteral stenting. Conversely, the development of endourological technologies allows a finer stone fragmentation and/or better elimination, thus reducing the risk of steinstrasse and decreasing the potential number of sessions or additional interventions. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Radial Extracorporeal Shock Wave Therapy Combined with Resveratrol Derivative Alleviates Chronic Nonbacterial Prostatitis in Rats

Resveratrol (Res) is a non-flavonoid polyphenol compound with biological pleiotropic properties, but low bioavailability limits its application value. Here, we synthesized a new Res derivative ((E)-5-(dimethylamino)-2-(4-methoxystyryl)phenol), and attempted to determine the function of Res derivative combined with radial extracorporeal shock wave therapy (rESWT) in chronic nonbacterial prostatitis (CNP). CNP model rats were constructed by subcutaneous administration of prostatein suspension (15 mg/ml), followed by rESWT treatment alone or in associated with Res or Res derivatives. In this study, inflammatory cell infiltration and tissue fibrosis in the prostate tissues of CNP rats were significantly deteriorated, which was effectively abolished by rESWT treatment alone or in combination with Res or Res derivative. The expression of interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), nerve growth factor (NGF), and nuclear factor kappa-B (NF-κB) were increased, while silent information regulator 1 (SIRT1) expression was suppressed in the prostate tissues of CNP rats, which were then rescued by rESWT treatment alone or in associated with Res or Res derivative. Importantly, compared with Res derivative treatment alone or rESWT combined with Res treatment, combination treatment with rESWT and Res derivative was more effective in alleviating inflammation and fibrosis, in reducing IL-1β, TNF-α, NGF, and SIRT1 expression, and in facilitating SIRT1 expression. Overall, rESWT combined with Res derivative treatment improved CNP in rat by reducing inflammation and fibrosis, which attributed to regulate the expression of SIRT1 and NF-κB. Thus, this work provides a theoretical basis for rESWT combined with Res derivative in the clinical treatment of CNP.

Pediatric Nephrolithiasis

The prevalence of pediatric nephrolithiasis has increased dramatically in the past two decades for reasons that have yet to be fully elucidated. Workup of pediatric kidney stones should include metabolic assessment to identify and address any risk factors predisposing patients to recurrent stone formation, and treatment should aim to facilitate stone clearance while minimizing complications, radiation and anesthetic exposure, and other risks. Treatment methods include observation and supportive therapy, medical expulsive therapy, and surgical intervention, with choice of treatment method determined by clinicians' assessments of stone size, location, anatomic factors, comorbidities, other risk factors, and preferences and goals of patients and their families. Much of the current research into nephrolithiasis is restricted to adult populations, and more data are needed to better understand many aspects of the epidemiology and treatment of pediatric kidney stones.

Supine versus prone percutaneous nephrolithotomy for renal calculi: Our experience

Objectives:

To compare operative times, safety, and effectiveness of percutaneous nephrolithotomy in the supine versus the prone position.

Materials and methods:

An observational study of 100 patients was conducted in our institution for 2years from 2018 to 2020 divided into 2 groups: 50 patients underwent modified supine percutaneous nephrolithotomy (PCNL) and 50 patients underwent standard prone PCNL. The inclusion criteria included a renal calculus (calyx or pelvis) of any size for which PCNL was indicated and exclusion criteria were patients having contraindications for PCNL such as bleeding disorders, pregnancy, high risk, and co-morbid conditions. The measured data included operative time, number of punctures, stone-free rate, length of hospital stays, and rate of complications.

Results:

The 2 groups were comparable in mean age, male to female ratio, calculus size, number of punctures, residual calculi, and postoperative fever and pain. The mean difference of hemoglobin in the supine PCNL group was 0.37 g/dL whereas in the prone PCNL group it was 0.61 g/dL. The p value was significant at 0.043. The mean time to finish from initial postion was 72.24 minutes in supine PCNL and 88.12 minutes in prone PCNL. The p value was significant (p < 0.001). The mean time before puncture was 20.92 minutes in the supine position and 31.84 minutes in the prone position. The p value was significant (p < 0.001). The mean time from puncture to finish was 51.32 minutes in the supine position and 56.28 minutes in the prone position. The p value was significant (p < 0.001).

Conclusions:

As observed from this study, supine PCNL is associated with a significantly reduced operating time when compared to conventional prone position PCNL procedures. The postoperative complications such as pain and fever were not significantly different. Hence, the supine PCNL is an equally effective modality for treatment of a renal calculus with benefits of simultaneous retrograde access and less operative time compared to the prone PCNL.

Therapeutic effects of flexible ureteroscopy alone and in combination with external physical vibration on upper urinary tract calculi: a randomized controlled trial

INTRODUCTION

Upper urinary tract calculus is a common disease of the urinary system.

AIM

To compare the therapeutic effects of flexible ureteroscopy alone and in combination with external physical vibration on upper urinary tract calculi.

MATERIAL AND METHODS

A total of 146 patients were randomly divided into control and experimental groups (n = 73). The control group received flexible ureteroscopy lithotripsy, and the experimental group underwent the same but combined with external physical vibration. The rate of finding stones in the urine on the day after treatment, clearance rate, components of stones, levels of renal function indices blood urea nitrogen (BUN) and serum creatinine (Scr), and incidence of complications were compared. The stone-free rate during 1-year follow-up was analysed by Kaplan-Meier method.

RESULTS

The rate of finding stones in the urine on the day after treatment was higher in the experimental group (100%) than that in the control group (29.73%) (p < 0.05). The clearance rates on the day, at 1 week, and at 2 weeks after treatment in the experimental group were 71.23%, 87.67%, and 95.89%, respectively, which surpassed those of the control group at corresponding time points (p < 0.05). BUN and Scr levels decreased after treatment in both groups, especially in the experimental group (p < 0.05). The stone-free rate during 1-year follow-up in the experimental group (n = 71 (97.26%)) exceeded that of the control group (n = 61 (83.56%)) (p < 0.05).

CONCLUSIONS

External physical vibration combined with flexible ureteroscopy lithotripsy significantly increased the rate of finding stones in the urine the day after treatment, the clearance rate of upper urinary tract calculi, and the ameliorated renal function and reduced the stone re-formation rate.

Guideline of the guidelines: urolithiasis

PURPOSE OF REVIEW

We reviewed the latest guidelines on urolithiasis to highlight the commonalities and differences in the most important recommendations.

RECENT FINDINGS

Most guidelines utilize systematic review of literature and grade evidence to generate the appropriate recommendations and statements. Only the latest versions of guidelines were included in this review.

SUMMARY

Four national and international guidelines were included in this review, including those of the EAU (European Association of Urology), the AUA (American Urological Association)/ES (Endourological Society), the UAA (Urological Association of Asia) and the NICE (National Institute for Health and Care Excellence) guidelines. There are general similarities in the most important recommendations. The EAU guidelines provide the latest evidence updates.

Epidemiology and risk factors for ureteral stent-associated urinary tract infections in non-transplanted renal patients: a systematic review of the literature

PURPOSE

Pathophysiology and risk factors for Ureteral Stent-Associated Urinary Tract Infection (USAUTI) have been poorly investigated. This situation results in highly diverse practices regarding USAUTI prevention, diagnosis and treatment. The aim of the present study was to describe the epidemiology and risk factors for USAUTI in non-transplanted patients.

METHODS

We conducted a systematic literature review based on a comprehensive PubMed® bibliographic strategy, between October 1998 and March 2020. The methodological quality of the studies included was analyzed according to dedicated grids. The main endpoints were the correlation between different potential risk factors and infection ureteral stent-associated urinary tract infection or colonization rate. Conclusions and their level of evidence were reported on the basis of a critical analysis of the best available scientific evidence. This work has been submitted to a national review, which enabled the potentially divergent opinions of experts to be collected, thereby ensuring adequate quality of data.

RESULTS AND CONCLUSION

Twenty-six studies out of the 505 articles identified, were included in the final analysis. Staphylococcus spp, E. coli, Klebsiella spp, Pseudomona aeruginosa, Enterococcus spp. and Candida spp. were the microorganisms most often responsible for asymptomatic bacteriuria (ABU) or USAUTI. Longer indwelling time, diabetes mellitus, female gender, chronic renal failure, diabetic nephropathy and cancer were identified as risk factors for ABU and ureteral stent colonization. No specific risk factor for UTI was identified in the literature studied. A causal relationship between ureteral stent colonization and USAUTI or urosepsis remains to be demonstrated.

Silodosin for Prevention of Ureteral Injuries Resulting from Insertion of a Ureteral Access Sheath: A Randomized Controlled Trial

BACKGROUND

The ureteral access sheath (UAS) is an ancillary device widely used by urologists, but acute ureter injury may occur following its insertion. Preoperative selective oral α1-blockers can reduce intraureteral pressure, and prevent ureteral wall injury during UAS insertion.

OBJECTIVE

To compare perioperative data of patients who underwent flexible ureterorenoscopy (fURS) with UAS with and without premedication with silodosin.

DESIGN, SETTING, AND PARTICIPANTS

Single-blind, 100 patients from a single institution who underwent retrograde intrarenal surgery for kidney and upper ureter stone removal were prospectively allocated from May 2018 to March 2019.

INTERVENTION

The experimental groups received silodosin for 3 d preoperatively.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint included ureteral injuries after UAS insertion that were assessed according to endoscopic classification. The secondary endpoint was an evaluation of whether premedication with silodosin had any effect on postoperative outcomes.

RESULTS AND LIMITATIONS

A total of 44 and 43 patients were randomly assigned to the control and experimental groups, respectively. Silodosin prevented significant postoperative ureteral injury involving the smooth muscle layer more successfully than in the control group (9.3% vs 27.3%; p = 0.031). There was no significant difference in the overall complication rate as determined by the modified Clavien-Dindo classification system and the computed tomography scan stone-free rate postoperatively. Patients who received silodosin before fURS reported lower pain scores than those in the control group using a visual analog scale (p = 0.009). Limitation included a lack of placebo comparison.

CONCLUSIONS

Our data suggest that preoperative silodosin protects against significant ureteral injury related to UAS insertion during fURS and decreases postoperative pain level. Silodosin premedication might be an effective and safe technique to replace prestenting.

PATIENT SUMMARY

We investigated the preventive effect of an α-blocker against perioperative complication caused by ureteral access sheath inserted during flexible ureterorenoscopy. Taking silodosin before surgery prevented ureter wall injury during surgery and immediately improved postoperative pain.

Effect of perioperative selective alpha-1 blockers in non-stented ureteroscopic laser lithotripsy for ureteric stones: a randomized controlled trial

Introduction

The aim of this studywas to assess the efficacy of perioperative alpha-1 blockers on improving the success rate and decreasing complications of non-stented ureteroscopic laser lithotripsy for ureteric stones.

Material and methods

A randomized control trial was conducted at two high volume urological centers from September 2017 to December 2018. We enrolled 150 patients with lower ureteric stones. They were randomly divided into two groups. Patients in group A, underwent non-stented ureteroscopy using Ho-YAG laser for stone disintegration and received alpha-1 blockers for one week preoperatively and another two weeks postoperatively. Patients in group B, underwent non-stented ureteroscopy and laser and received a placebo.

Results

One hundred and twenty patients were available for analysis at the end of our study. There was no statistically significant difference found between both groups regarding demographic data and stone parameters. The need for intraoperative ureteric dilatation was 32.7% and 51.6% for both groups A and B respectively with a statistically significant difference. The incidence of lower urinary tract symptoms (LUTS) and the need for analgesics were higher in group B with a statistically significant difference.

Conclusions

Administration of perioperative tamsulosin seems to not only to significantly decrease the need for intra-operative dilatation and hence operative time, but also leads to a significant decrease in the development of postoperative LUTs, postoperative pain and the need for analgesia and hospital stay.

Immediate Shockwave Lithotripsy vs Delayed Shockwave Lithotripsy After Urgent Ureteral Stenting in Patients with Ureteral or Pyeloureteral Urolithiasis: A Matched-Pair Analysis

Introduction: The most common cause of acute renal colic is a ureteral obstruction caused by ureterolithiasis. Urgent intervention is often necessary due to intractable pain. Early extracorporeal shockwave lithotripsy (SWL) as an alternative treatment option to ureteral stenting becomes forgotten in times of rising ureterorenoscopy. However, definitive guidelines are lacking, in which urgent treatment should be preferred in the absence of signs of infection. Therefore, we assessed efficacy and safety of early SWL (eSWL) to secondary SWL (sSWL) after urgent ureteral stenting. Patients and Methods: One hundred four patients treated between January 2015 and November 2017 for obstructive ureterolithiasis were matched regarding stone size, stone localization, and assigned to group eSWL (n = 52) or group sSWL (n = 52). The eSWL group received shock waves (without prior ureteral stenting) and sSWL group ureteral stenting within 48 hours from diagnosis. Thereafter, patients in group sSWL were treated with shock waves for a median of 23 ± 14.6 days after ureteral stenting. Stone-free rates, complication rates, and reintervention rates were assessed. Univariable and multivariable logistic regression was applied to find predictors of outcomes in the two treatment groups. Results: Overall, there was no statistically significant difference between both groups regarding stone-free rate and complication rate. Reinterventions were more often addressed for patients in group sSWL (p = 0.05). eSWL was significantly superior to sSWL regarding stone-free rates for stones between 6 and 9 mm (p = 0.04). At the multivariable multinomial logistic regression none of the two treatment modalities was associated with better outcomes. A body mass index ≥30 was associated with a reduced 6-week stone-free status (p = 0.04), whereas stones ≥8 mm were associated with an increased need of reintervention (p = 0.04). Conclusion: eSWL seems to be an effective and safe emergency procedure compared with sSWL after urgent stenting within 6 weeks and should be considered as a treatment option in patients without absolute indications for immediate ureteral drainage. Clinical trial registration number: 2019-00155.

Is health-related quality of life of patients after single-use flexible ureteroscopy superior to extracorporeal shock wave lithotripsy? A randomised prospective study

The aims of the study were to compare the change in the Wisconsin Stone Quality of Life (WISQOL) score in patients who underwent retrograde intrarenal surgery (RIRS) single-use ureteroscope or extracorporeal shock wave lithotripsy (ESWL) with a calculation of quality-adjusted life-years (QALYs). 158 patients treated with urinary stone disease were randomly divided into 80 patients in the validation and 78 patients in the intervention arm. Patients in the intervention arm were randomly divided into the RIRS or the ESWL group. Linguistic validation of the WISQOL into the Slovak language was performed using a standardised multistep process. Discriminant validity was assessed by comparing stone-forming patients to an additional 34 healthy individuals. Patients were asked to fill in the WISQOL before and in the 24th week after the intervention. The QALYs were calculated by the formula QALY = weight factor (WF) x time period after intervention. The Cronbach's α of the WISQOL was 0.94, the Pearson's coefficient for test-retest reliability was 0.91, and the discriminant validity confirmed a higher score for healthy individuals (p < 0.001). The median WISQOL score changed from 45.5 to 95.5 vs. 33.9 to 87.1 in the RIRS and ESWL groups, respectively (p < 0.001). Patients from the RIRS group had a good possibility of reaching 19.727 QALYs gained during life expectancy compared to 15.780 for the ESWL group (p < 0.001). RIRS single-use ureteroscope is significantly superior to ESWL in reaching more QALYs gained during life expectancy. The WISQOL Slovak version is valid, reliable and strictly specific for stone-forming patients.

How to maximize the efficacy of shockwave lithotripsy

Since its introduction in the early 1980s, extracorporeal shockwave lithotripsy (ESWL) has proven to be a minimally invasive and efficient procedure for the management of renal calculi. It is currently one of the most recommended treatments for small- and medium-sized stones (<20 mm) in most guidelines internationally. The recent coronavirus disease 2019 (COVID-19) outbreak could lead to a further increase in ESWL use as it avoids a general anesthetic and its potential complications in patients with COVID-19 infection. Most publications exhibit ESWL stone-free rates (SFRs) of 70%-80%; however, this is often not the case in many centers, with multiple factors affecting the efficacy of the intervention. Various stone and patient factors have been shown to influence the ESWL success. Stone position, density and size, skin-to-stone distance, and body-mass index contribute to SFRs. Modifications in the lithotripter design and revisions in the technique have also improved the SFRs over the years, with slower shock rates, power-ramping protocols, combined real-time ultrasound, and fluoroscopy imaging technology, all enhancing the efficacy. The adjuvant use of pharmacological agents, such as alpha-blockers, potassium citrate, and the emerging microbubble technology, has also been investigated and shown promising results. Arguably, the most significant determinant of the success of ESWL in a particular unit is how the lithotripsy service is set up and monitored. Careful patient selection, dedicated personnel, and post-treatment imaging review are essential for the optimization of ESWL. Through an analysis of the published studies, this review aimed to explore the measures that contribute to an effectual lithotripsy service in depth.

Guideline of guidelines for kidney and bladder stones

Urological organizations publish detailed evidence-based guidelines to support the urologists in the management of urolithiasis. Our objective was to provide clear guidance on the management of urolithiasis, compare the American Urological Association (AUA) and European Association of Urologists (EAU) guidelines, and present an algorithm for different clinical scenarios. The latest AUA and EAU guidelines on urolithiasis were evaluated for the level of evidence and grade of recommendation. All recommendations on management of urolithiasis (surgical and medical management) were reviewed and included. Both the organizations provide guidance for initial patient assessment, imaging requirements, and therapeutic options, including surgical intervention and medical therapy. In addition, these guidelines provide advice for managing specific patient groups, including pediatric patients and pregnant patients. Although there is a general concordance between both the groups, differences exist particularly for recommended modality of surgical intervention depending on stone location and size. Although both the guidelines were broadly similar, we also highlighted the variations in the level of evidence and grade of recommendation. Although these guidelines provide a valuable evidence-based framework to support the management of urinary tract stones, their implementation must be tailored to individual patient needs and available resources.

Survey on ureTEric draiNage post uncomplicaTed ureteroscopy (STENT)

Objectives

To assess the feasibility of conducting a randomised controlled trial (RCT) to assess whether avoiding ureteric drainage is superior to performing ureteric drainage after Uncomplicated Ureteroscopy and/or Flexible Ureterorenoscopy (URS/FURS) treatment of a urinary tract stone in improving patient reported outcome measures (PROMs) and 30‐day unplanned readmission rates. A secondary objective was to understand current practice of urologists regarding ureteric drainage after uncomplicated URS/FURS (UU).

Material and methods

We undertook an online survey of urologists, circulated amongst members of international urological societies and through social media platforms. Uncomplicated URS/FURS was defined as completion of URS/FURS treatment for a urinary tract stone, with the absence of: ureteral trauma, residual fragments requiring further lithotripsy procedures, significant bleeding, perforation, prior urinary tract infection or pregnancy. The ureteric drainage options considered included an indwelling stent, stent on a string or a ureteric catheter. The primary outcome was to determine the proportion of urologists willing to take part in a RCT, randomising patients after UU to a “no ureteric drainage” arm or ureteric drainage arm. Secondary outcomes included determining in their current practice, the proportion of clinicians performing routine ureteric drainage after UU, the reasons for performing ureteric drainage following UU and their preferred optimal duration for ureteric drainage if it is used. The study was reported according to the Checklist for Reporting Results of Internet E‐Surveys (CHERRIES).

Results

Total of 468 respondents from 45 countries took part in the survey, of whom 303 completed the entire survey (65%). The majority agreed that they would be willing to randomise patients (244/303, 81%) in the proposed RCT. Perceived lack of equipoise to randomise was the most common reason for not being willing to participate (59/303, 19%).

92% (308/335) reported that they use ureteric drainage after UU. This was most often due to wanting to prevent possible complications from post‐operative ureteric oedema (77%) or to aid passage of small fragments (43%). Complexity of the case (i.e. impacted stone 90%) and length of the procedure (46%) were the most important intraoperative factors influencing the decision to use ureteric drainage post procedure. If required, the median stated ideal duration of ureteric drainage was 5 days (IQR: 3–7 days) after UU. If having UU personally, 30% would want no stent postoperatively and over half would prefer a stent on a string.

Conclusion

We have highlighted wide variation in practice regarding ureteric drainage after UU. Our results support the feasibility of an RCT evaluating if no ureteric drainage is superior to ureteric drainage in improving PROMs and 30‐day unplanned readmission rates following UU.

Shockwave Lithotripsy Use in the State of Michigan: American Urological Association Guideline Adherence and Clinical Implications

OBJECTIVE

To understand how treatment of patients with urinary stones by shockwave lithotripsy (SWL) aligns with current published practice guidelines.

METHODS

We used the Michigan Urologic Surgery Improvement Collaborative Reducing Operative Complications for Kidney Stones registry to understand SWL use in the state of Michigan. This prospectively maintained clinical registry includes data from community and academic urology practices and contains clinical and operative data for patients undergoing SWL and ureteroscopy (URS). We identified patients undergoing SWL from 2016 to 2019. In accordance with AUA guidelines, we evaluated practice patterns in relation to recommendations for treatment selection for SWL as well as clinical implications of guideline nonadherence.

RESULTS

Four thousand, two hundred and nine SWL procedures performed across 34 practices were analyzed. Perioperative antibiotics were administered to 61.3% of patients undergoing SWL. A ureteral stent was placed at the time of SWL in 2.7% of patients. For lower pole renal stones >1 cm or large (>2 cm) renal stones in the registry, 32.2% and 58.9% of patients, respectively, underwent SWL, while the remainder were treated with URS. In these instances, SWL was associated with inferior stone-free rate (SFR) relative to URS. In patients with residual stones after SWL, 34.6% were treated with repeat SWL with lower SFR than those treated with subsequent URS. Postoperatively, 42.1% of patients were prescribed alpha-blockers with no benefit seen in terms of SFR.

CONCLUSION

Substantial variation exists among urology practices with regard to SWL use. These data serve to inform quality improvement efforts regarding appropriateness criteria for SWL in Michigan.

Effect of JJ stent on outcomes of extracorporeal shock wave lithotripsy treatment of moderate sized renal pelvic stones: A randomized prospective study

PURPOSE

To evaluate the effect of JJ stents on SWL treatment of moderate (15-25mm) renal pelvic stones.

MATERIALS AND METHODS

Between January 2016 and December 2017, a total of 152 adult patients who were planned to undergo SWL for a single radiopaque renal pelvic stone were included in the study. Patients with solitary kidney, congenital abnormality, skeletal tract abnormalities, previous urinary system surgery, hydronephrosis (grade 2 or more), untreated urinary tract infection, bleeding disorder, and suspected pregnancy were excluded. The remaining 114 patients were randomly divided into two groups; non-stented and stented. Twenty-two patients whose stone could not be fragmented despite 3 consecutive sessions were also excluded from the study. A total of 92 patients (54 non-stented and 38 stented) were included in the final analysis.

RESULTS

There was no significant difference in terms of age, sex, body mass index, renal parancyhimal thickness, hydronephrosis, skin-to-stone distance, Hounsfield units, and stone size between the groups. Success was significantly higher in the stented group than in the non-stented group (71% vs. 39%, P=.002). In stone-free patients, the number of emergency department visits and analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P<.001 and P<.001, respectively). In non- stone-free patients, analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P=.004).

CONCLUSIONS

Pre-stenting before SWL treatment of moderate sized renal pelvic stones has some advantages in terms of success, emergency service visits, and analgesic tablet consumption.

Encrusted Ureteral Stent in a Spanish Speaking Female: A Case of a Forgotten Stent Lost in Translation

Ureteral stents are used to establish patency in a non-draining ureter, as they are commonly placed in etiologies such as ureteral obstruction and urological surgery. One complication that occurs with stent placement is the absence of follow-up to remove the device. This may be due to a myriad of reasons, including non-compliance and lack of patient education. Forgotten stents can pose a dangerous scenario, as a retained stent can lead to urinary tract obstruction, urosepsis, and even kidney failure. In this study, we present a case of a Spanish-speaking patient with a retained ureteral stent who presented with left flank pain due to not understanding the need for stent follow-up.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes

For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Ureteral stents in urolithiasis

Ever since the ureteral stent design was fitted with a curl on both sides to prevent it from migrating up or down the ureter some 40 years ago, its use has gained tremendous momentum, aiding in the rise and evolution of endourology and has confidently kept its place in modern time urology. Over the past four decades, several designs, coating and biomaterials have been developed, trying to reduce infection, encrustation and other stent related symptoms. As the ideal stent has not yet been discovered, different ways of helping patients with their complaints have been researched. This review will cover these aspects of stent use in urolithiasis.

British Association of Urological Surgeons standards for management of acute ureteric colic

These guidelines have been developed by the British Association of Urological Surgeons to give a framework to clinicians, based primarily in the UK, for the management of patients presenting acutely with ureteric colic. They have been developed by consensus with reference to the American Urological Association/Endourological Society guidelines on the surgical management of stones and the European Association of Urology guidelines on urolithiasis, and adapted to the logistics of those practicing within the National Health Service. Grades of recommendation and levels of evidence are based upon the system adopted by the European Association of Urology.

Extracorporeal shock wave lithotripsy (ESWL) monotherapy in children: Predictors of successful outcome

INTRODUCTION AND OBJECTIVES

Although extracorporeal shock wave lithotripsy (ESWL) is the first choice for pediatric renal calculi <2 cm, the success rate after the first session is low. This is in contrast to other minimally invasive procedures like percutanous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS), which have higher rates of success. Therefore, the present study sought to identify predictors of success after one session of ESWL.

PATIENTS AND METHODS

A prospective study including 100 children with renal stone burden <2 cm who underwent ESWL at the present institution. The success rate after the first session was analyzed, and the predictors of success were investigated. The success of ESWL monotherapy was defined by absence of any residual fragments after 3 months, on non-contrast spiral computerized tomography (NCCT) scan, without need of any additional intervention.

RESULTS

Between January 2013 and October 2015, 100 children were treated with a Dornier Gemini lithotripter at the present institution. The mean patients age and stone size were 6 years (range: 1.8-14) and 13.1 mm (range: 6-20), respectively. After one session, 47% of patients showed complete clearance 3 months postoperative, those patients versus those who required an additional session or auxiliary procedures were younger in age, with smaller stone size and lower density. On multivariate analysis, only patient age was an independent predictor of success (odds ratio (OR) 0.9; P < 0.001).

CONCLUSION

Patient's age was an important predictor for response after ESWL monotherapy: not only did children respond better than adults, but age was also an independent predictor within the pediatric group.

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.

Immediate versus delayed shockwave lithotripsy for inaccessible stones after uncomplicated percutaneous nephrolithotomy

Objective

To evaluate the efficacy and safety of immediate versus delayed shockwave lithotripsy (SWL) for inaccessible stones after uncomplicated percutaneous nephrolithotomy (PCNL).

Patients and methods

Between December 2011 and June 2014, patients with residual inaccessible stones after uncomplicated PCNL were prospectively randomised into two treatment groups; Group I, immediate SWL and Group II, delayed SWL at 1 week after PCNL. Patients with residual stones of ⩾1.5 cm, a stone density of >1000 Hounsfield units and body mass index of >40 kg/m² were excluded from the study. The following data were reported: patients’ demographics, stone characteristics after PCNL, hospital stay, perioperative complications, stent duration, and stone-free rate (SFR).

Results

In all, 84 patients (51 males and 33 females) with mean (SD) age of 39 (8.5) years were included in the study. Group I included 44 patients, whilst Group II included 40 patients. There was no statistically significant difference amongst the groups for patients’ demographics, stone characteristics, and perioperative complications. The hospital stay was significantly shorter in Group I, at a mean (SD) of 34 (3.7) vs 45 (2.9) h (P < 0.001). The duration of ureteric stenting was significantly lower in Group I as compared to Group II, at a mean (SD) of 12 (4.2) vs 25 (3.5) days (P < 0.001). The SFR was 93.2% and 95% in Groups I and II, respectively (P = 0.9).

Conclusions

Immediate SWL after PCNL is as effective and safe as delayed SWL with a lesser hospital stay and duration of ureteric stenting.

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.

Has the pelvic renal stone position inside the upper loop of JJ stent any influence on the extracorporeal shock wave lithotripsy results?

Background

JJ stents are often encountered in patients with pelvic renal stones referred for shock wave lithotripsy, most of them being placed either for obstructive renal pelvic stones or for ureteric stones mobilized retrograde during the JJ stent insertion. The aim of the study was to determine whether the relative stone position in the upper loop of the JJ stent during extracorporeal shock wave lithotripsy (SWL) influences the efficiency of the procedure. The study was designed as a prospective cohort study on 162 patients addressing the same urological department, with single renal pelvic stone (primary or mobilized to the renal pelvis during the insertion of JJ stent), smaller than 15 mm, with JJ stent, treated by SWL using a second generation spark gap lithotripter, 18 kV, 3000 waves/session. Patients were divided in three groups according to the relative position of the stone to the upper loop of the JJ stent as appears on plain X-ray: stone-inside-loop, loop-crossing-stone and stone-outside the loop. The SWL success rate was the primary outcome of the study. p Value, Chi square and Kruskal–Wallis tests were used for statistical analysis.

Results

For stone-inside-loop cases, SWL efficiency was 22.7 versus 42 % for all the other cases (p = 0.002). Other factors for decreased SWL success rate were: higher stone radio-opacity, larger JJ of stent and obese patients. Study limitation is represented by the relative small study group and by the evaluation of stone density using plain X-ray instead of computer tomography.

Conclusions

For pelvic renal stones having the same density characteristics studied by plain X-ray, the SWL efficiency is lower in stone-inside-loop cases comparing with the other positions. The overall stone free rate for renal pelvic stones could be explained by the second generation lithotripter used for all procedures.

Surgical Management of Stones: American Urological Association/Endourological Society Guideline, PART II

PURPOSE

This Guideline is intended to provide a clinical framework for the surgical management of patients with kidney and/or ureteral stones. The summary presented herein represents Part II of the two-part series dedicated to Surgical Management of Stones: American Urological Association/Endourological Society Guideline. Please refer to Part I for introductory information and a discussion of pre-operative imaging and special cases.

MATERIALS AND METHODS

A systematic review of the literature (search dates 1/1/1985 to 5/31/2015) was conducted to identify peer-reviewed studies relevant to the surgical management of stones. The review yielded an evidence base of 1,911 articles after application of inclusion/exclusion criteria. These publications were used to create the Guideline statements. Evidence-based statements of Strong, Moderate, or Conditional Recommendation were developed based on benefits and risks/burdens to patients. Additional directives are provided as Clinical Principles and Expert Opinions when insufficient evidence existed.

RESULTS

The Panel identified 12 adult Index Patients to represent the most common cases seen in clinical practice. Three additional Index Patients were also created to describe the more commonly encountered special cases, including pediatric and pregnant patients. With these patients in mind, Guideline statements were developed to aid the clinician in identifying optimal management.

CONCLUSIONS

Proper treatment selection, which is directed by patient- and stone-specific factors, remains the greatest predictor of successful treatment outcomes. This Guideline is intended for use in conjunction with the individual patient's treatment goals. In all cases, patient preferences and personal goals should be considered when choosing a management strategy.

Impact of ureteric stent on outcome of extracorporeal shockwave lithotripsy: A propensity score analysis

INTRODUCTION

Extracorporeal shockwave lithotripsy (SWL) is one of the most frequently performed procedures in patients with urolithiasis. For ureter-localized stones, SWL is often preceded by a double J stent insertion. However, fear of serious complications, including sepsis associated with stents, is often expressed. The following study assessed the impact of stent insertions on the results of SWL in patients with ureteric stones.

MATERIAL AND METHODS

The study group consisted of 411 ureteric stone patients who were treated with SWL from January 2010 to December 2014. In 60 cases, treatment was preceded by ureteric stent insertion. A propensity scoring system was used to pair non-stented patients with the stented group. Success rates were assessed and compared using the chi-squared test. Multivariate logistic regression analysis was used to evaluate the influence of particular variables on the stone-free rate.

RESULTS

The overall success rate was 82.2%. After matching, the success rate of the stented group was not significantly different from the control group (85.0% vs. 83.3% respectively, p = 0.80). The mean number of sessions was higher in the stented group (1.88 per patient). Stones located in the lower part of the ureter have the greatest chance of being successfully treated.

CONCLUSIONS

The double J stent has no influence on the outcome of SWL treatment. In view of the greater likelihood of having additional sessions, this approach should be reserved for selected cases.

History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis

To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy.

Extracorporeal shock wave lithotripsy in the treatment of renal and ureteral stones

The use of certain technical principles and the selection of favorable cases can optimize the results of extracorporeal shock wave lithotripsy (ESWL). The aim of this study is to review how ESWL works, its indications and contraindications, predictive factors for success, and its complications. A search was conducted on the Pubmed® database between January 1984 and October 2013 using "shock wave lithotripsy" and "stone" as key-words. Only articles with a high level of evidence, in English, and conducted in humans, such as clinical trials or review/meta-analysis, were included. To optimize the search for the ESWL results, several technical factors including type of lithotripsy device, energy and frequency of pulses, coupling of the patient to the lithotriptor, location of the calculus, and type of anesthesia should be taken into consideration. Other factors related to the patient, stone size and density, skin to stone distance, anatomy of the excretory path, and kidney anomalies are also important. Antibiotic prophylaxis is not necessary, and routine double J stent placement before the procedure is not routinely recommended. Alpha-blockers, particularly tamsulosin, are useful for stones >10mm. Minor complications may occur following ESWL, which generally respond well to clinical interventions. The relationship between ESWL and hypertension/diabetes is not well established.

Extracorporeal shock wave lithotripsy for management of residual stones after ureterolithotripsy versus mini-percutaneous nephrolithotomy: a retrospective study

Purpose

To compare the efficacy of extracorporeal shock wave lithotripsy in managing residual stones after ureterolithotripsy and mini-percutaneous nephrolithotomy.

Materials and Methods

A retrospective study was carried out of 71 patients with proximal urinary tract stones (greater than 10 mm) who underwent ureterolithotripsy or mini-percutaneous nephrolithotomy at a single institution from 2009 to 2011. The 71 patients were divided into two groups: group I (n = 37) comprised patients who underwent ureterolithotripsy, and group II (n = 34) comprised patients who underwent mini-percutaneous nephrolithotomy. Clinical characteristics, stone-free rates, stone demographics, and complications were evaluated.

Results

The overall stone-free rate was 90.1%. The stone-free rates in groups I and II were 97.3% and 82.4%, respectively. There was a statistically significant difference in the stone-free rates between groups I and II (P = 0.035). Neither serious intraoperative nor postoperative complications were observed. No significant difference in complications was observed between the two groups (P = 0.472).

Conclusions

The results of our study suggest that extracorporeal shock wave lithotripsy is an effective and safe auxiliary procedure for managing residual stones after primary endoscopic surgery. This procedure is associated with a satisfactory stone-free rate and a low complication rate, particularly for residual stones after ureteroscopic procedures.

Recent finding and new technologies in nephrolitiasis: a review of the recent literature

This review summarizes recent literature on advances regarding renal and ureteral calculi, with particular focus in areas of recent advances in the overall field of urolithiasis. Clinical management in everyday practice requires a complete understanding of the issues regarding metabolic evaluation and subgrouping of stone-forming patients, diagnostic procedures, effective treatment regime in acute stone colic, medical expulsive therapy, and active stone removal. In this review we focus on new perspectives in managing nephrolitihiasis and discuss recentadvances, including medical expulsive therapy, new technologies, and refinements of classical therapy such as shock wave lithotripsy, give a fundamental modification of nephrolithiasis management. Overall, this field appears to be the most promising, capable of new developments in ureterorenoscopy and percutaneous approaches. Further improvements are expected from robotic-assisted procedures, such as flexible robotics in ureterorenoscopy.