Intrarenal pressure detection during flexible ureteroscopy with fiber optic pressure sensor system in porcine model

To validate the feasibility of a fiber-optic pressure sensor-based pressure measurement device for monitoring intrarenal pressure and to analyze the effects of ureteral acess sheath (UAS) type, surgical location, perfusion flow rate, and measurement location on intrarenal pressure (IRP). The measurement deviations and response times to transient pressure changes were compared between a fiber-optic pressure sensing device and a urodynamic device IRP in an in vitro porcine kidney and in a water tank. Finally, pressure measurements were performed in anesthetized female pigs using fiber-optic pressure sensing device with different UAS, different perfusion flow rates, and different surgical positions at different renal calyces and ureteropelvic junctions (UPJ). According to our operation, the result is fiber optic pressure sensing devices are highly accurate and sensitive. Under the same conditions, IRP varied among different renal calyces and UPJ (P < 0.05). IRP was lowest at 50 ml/min and highest at 150 ml/min (P < 0.05). Surgical position had a significant effect on IRP (P < 0.05). 12/14 Fr UAS had a lower IRP than 11/13 Fr UAS. Therefore fiber optic pressure sensing devices are more advantageous for IRP measurements. In ureteroscopy, the type of ureteral sheath, the surgical position, the perfusion flow rate, and the location of the measurement all affect the intrarenal pressure value.

Initial experience with slimmest single-use flexible ureteroscope Uscope PU3033A (PUSEN™) in retrograde intrarenal surgery and its comparison with Uscope PU3022a: a single-center prospective study

PURPOSE

Single-use disposable digital flexible ureterorenoscope has become an attractive option to reusable scope with many advantages. Currently available single-use digital fURS have outer shaft diameter above 9 Fr which requires large access sheath insertion and sometimes double J stent placement. Recently, 7.5 Fr single-use digital fURS is introduced in market by Pusen. Objective of this study is to compare two Pusen single-use scopes in the clinical setting: 7.5 Fr Uscope PU3033A and 9.5 Fr Uscope PU3022A.

METHODS

30 patients, having renal stones < 2 cm, planned for RIRS were prospectively randomized to two groups: group 1 had 15 patients in which 7.5 Fr Uscope PU3033A and group 2 had 15 patients in which 9.5 Fr Uscope PU3022A was used. The various pre-operative, intra-operative, and post-operative parameters at 1 month along with complications were evaluated for both the scopes by a single surgical team.

RESULTS

Pre-operative parameters including stone characteristics were comparable in both the groups. Three patients in group 2 needed ureteric dilatation prior to 11/13 access sheath insertion, while 10/12 Fr access sheath was placed in all patients in group 1 without manipulation (p = 0.06). Intra-operative vision was comparable in both scopes with an empty working channel and with laser. Hazy vision while lasing in two and one patient in group 1 and group 2, respectively (p = 0.54). In group 1, one had fever and UTI, while in group 2, one had fever post-operatively.

CONCLUSION

7.5 Fr Uscope PU3033A could be introduced with smaller access sheath. The vision, deflection, maneuverability is comparable to 9.5 Fr Uscope PU3022a.

Effects of Chlorpheniramine Maleate on Catheter-Related Bladder Discomfort in Patients Undergoing Ureteroscopic Stone Removal: A Randomized Double-Blind Study

Catheter-related bladder discomfort (CRBD) associated with intraoperative urinary catheterization is a distressing symptom during recovery from anesthesia. Anticholinergics have been used to manage CRBD. Chlorpheniramine maleate (CPM) is a first-generation antihistamine, which also has anticholinergic effects. This study was undertaken to evaluate the efficacy of CPM in preventing CRBD. Seventy-six adults (19-65 years old) with American Society of Anesthesiologists physical status I, II, or III of either sex, undergoing elective ureteroscopic stone removal under general anesthesia were randomized into one of two groups (each n = 38). Group C (control) received a placebo, and group CPM received 8 mg of intravenous CPM before the induction of anesthesia. CRBD was assessed upon arrival in the post-anesthetic care unit at 0, 1, 2, and 6 h. The severity of CRBD was graded as none, mild, moderate, and severe. Tramadol was administered when the severity of CRBD was more than moderate. The incidence rate and overall severity of CRBD did not differ between the groups at any of the time points (р > 0.05). The incidence of moderate CRBD was higher in group C than in group CPM only at 0 h (26.3% vs. 5.3%, р = 0.025). However, fewer patients in the CPM group required rescue tramadol to relieve CRBD after surgery (31.6% vs. 60.5%, р = 0.011). CPM administration before the induction of anesthesia had little effect on the incidence and severity of CRBD after surgery, but it reduced the administration of tramadol required to control CRBD postoperatively.

A Longitudinal Cohort Study of Pain Intensity and Interference After Ureteroscopy for Nephrolithiasis Without Postoperative Opioids

OBJECTIVE

To better understand the degree and time to resolution of pain in the postoperative period, we captured patient-reported pain intensity and interference prospectively in patients following ureteroscopy for nephrolithiasis.

MATERIALS AND METHODS

Adults undergoing ureteroscopy for renal/ureteral stones from 11/2018 to 1/2020 were eligible for inclusion. All received nonopioid postoperative pain control. Patients prospectively completed Patient-Reported Outcome Measurement Information System-Pain Intensity and Patient-Reported Outcome Measurement Information System-Pain Interference instruments preoperatively on postoperative day (POD) 0 and via email on POD 1, 7, and 14. Scores are reported as T-scores (normalized to US population, mean = 50) with changes of 5 (0.5 standard deviation) considered clinically significant.

RESULTS

A total of 126 patients completed enrollment at POD 0 (POD 1 = 74, POD 7 = 61, POD 14 = 47). Compared to US means, intensity and interference were significantly different at all time point comparisons (Wilcoxon rank test; all P <.001) except intensity at POD 7 (P = .09) and interference at POD 14 (P = .12). For both, there was a significant difference at each time comparison (repeated measures ANOVA; all P <.05). Increasing age was predictive of lower intensity (Confidence Interval (CI): -0.31 to -0.04; P = .012) and interference (CI: -0.36 to -0.06; P =.01) at POD 1. The presence of a postoperative stent was predictive of higher intensity (CI: 0.68-10.81; P = .03) and interference (CI: 0.61-12.96; P = .03) at POD 7. Increasing age remained a predictor of lower interference at POD 1 on multivariable analysis (CI: -0.46 to -0.01; P = .03).

CONCLUSION

Pain intensity and interference are elevated immediately, but intensity normalizes by POD 7, while interference remains elevated until POD 14. Age and indwelling ureteral stent influence both intensity and interference.

Operator-assisted vs self-achieved basketing during ureteroscopy: results from an in vitro preference study

OBJECTIVES

A recently introduced device (LithoVue Empower™ or LE, Boston Scientifics, USA) allows the surgeon to directly control the stone-retrieving basket without the need of an assistant during flexible ureteroscopy. We aimed to evaluate the stone-retrieval performance of this device.

METHODS

We used a bench-training model for flexible ureteroscopy, the Key-box (K-Box®, Porgès-Coloplast, France), to compare the LE configured with a 1.9F stone-retrieval tipless basket (ZeroTip™, Boston Scientific, USA) and a traditional assistant-maneuvered 1.9F stone-retrieval tipless basket. Seven experienced endo-urologists and seven residents-in-training retrieved a fake stone from three different renal cavities of the K-Box with increasing access complexity first with the traditional basket and then with the LE device. We recorded retrieval time and all the operators filled in the NASA Task Load Index (TLI) for the self-evaluation of their performance. We then compared the use of LE in terms of retrieval time, failure rates, and NASA-TLI scores.

RESULTS

Stone retrieval times and failure rates were similar according to the retrieval technique, although residents had non-statistically significant shorter times with the LE. NASA-TLI scores revealed lower frustration (p = 0.03) when LE was used by experienced urologists as compared to the traditional basketing. When stratifying the analyses according to surgical experience, fully trained urologists performed faster stone retrieval and showed lower effort scores than residents-in-training (p < 0.05).

CONCLUSIONS

The individually controlled retrieval system is an effective device assisting stone retrieval and does not necessitate specific training among experienced endo-urologists. Young residents might benefit from LE during their learning curve.

Comparative investigation of reusable and single-use flexible endoscopes for urological interventions

In order to evaluate the technical adaptability of a type of disposable endoscope compared to reusable flexible endoscopes, in vitro and in vivo studies were conducted. A disposable digital ureteroscope ("chip on tip") and two reusable endoscopes were investigated with respect to spatial resolution, geometric distortion in air and water the maximum. Additionally, the clinical performance of the disposable device was tested during clinical procedures (n = 20). The disposable endoscope showed an optical resolution of 6.72 lines/mm at 10 mm distance, similar to the other devices. In comparison, the disposable endoscope showed a barrel-shaped image distortion in air of -24.2%, which is in the middle range, but was best under water (-8.6%). The bendability of 297° (275 µm fiber) and 316° (empty channel, 1.5 F basket) and the maximum irrigation (1 m: 58.1 ml/min, 2 m: 91.9 ml/min) were convincing. Clinically the maneuverability was very good in (13/20), good or satisfactory in (7/20). Visibility was evaluated as very good in (11/20), just in (1/20) either satisfactory or sufficient. The consistency of visibility was not affected in (19/20). In all cases there were no adverse events. The technical examination and clinical application of the disposable endoscope are of equal quality compared to reusable devices. Disposable endoscopes can be an alternative to reusable devices, but economic aspects such as reduction of repair costs, sterilization effort and additional waste must be taken into account.

The safety wire with a ureteral access sheath - does it hurt more than it helps?

INTRODUCTION

Studies indicate that with a safety wire in the ureter, an increased amount of force is necessary to advance ureteral access sheaths up to the proximal ureter. Theoretically, the compression of the ureter with the wire could lead to an increase in number and severity of ureteral injuries secondary to placement of a sheath. This prospective study aims to evaluate if there is a correlation between the use of a safety wire and ureteral injury from sheath placement by evaluating the location of the wire in relation to the injury after ureteroscopy.

MATERIALS AND METHODS

Fifty-nine consecutive patients underwent ureteroscopy for upper tract urinary stone disease. A 12/14 French ureteral access sheath was used with a safety wire in place. Ureteroscopy during withdrawal of the sheath was video recorded and reviewed by a blinded observer. Visible ureteral injuries were graded per the Traxer ureteral injury scale and the proximity of the wire to the injury was noted.

RESULTS

Thirty-one of 59 patients (52.4%) had a ureteral injury secondary to access sheath placement. Eighteen (30.5%) injuries were low-grade, 13 (22.0%) were high-grade (grade 2 and 3) and there were no grade 4 injuries. A total of 10 (32.3%) injuries occurred on the same side as the wire while 67.7% were on the contralateral side of the ureter. Of the injuries that occurred on the same side as the wire, 80% were grade 1 injuries and 2 (20%) were grade 3. Statistical analysis did not show a significant relationship between high/low injury grade and side of injury (p value = 0.088). This suggests that there is no association of between the safety wire and development of high injury.

CONCLUSION

There is no association between the location of the safety wire and ureteral injury if injury occurs during the placement of a ureteral access sheath. This suggests that the use of a safety wire does not add significant morbidity to the procedure.

Efficacy and Safety of Ultrasonic Longitudinal-Axis Vibration for the Reduction of Ureteral Access Sheath Insertion Force: A Randomized Controlled Trial in a Porcine Model

PURPOSE

Excessive bulking force during ureteral access sheath (UAS) placement may induce injury. The sliding friction between surfaces can be reduced with the application of ultrasonic vibration. We investigated the efficacy and safety of an ultrasonic vibration transducing device for reducing the maximal ureteral access sheath insertion force (UASIF).

MATERIALS AND METHODS

A device was developed for transducing ultrasonic longitudinal-axis vibration onto the UAS at an adjustable amplitude and frequency while measuring the degree of UASIF. In the pilot study, six porcine models were used to investigate the optimal amplitude and frequency of vibration and to calculate sample size. Twelve porcine models were utilized in a randomized controlled trial. Resected ureters were pathologically evaluated for ureteral injury.

RESULTS

The transduction of ultrasonic vibration at an amplitude of 0.04 g and a frequency of 18,000 Hz resulted in a maximal UASIF reduction of 36.4% (interquartile range 32.7-43.1). Maximal UASIF tended to decrease with increasing vibration frequency. No significant differences in UASIF reductions were observed according to amplitude. In the randomized controlled trial, the maximal UASIF reduction was 37.0% (interquartile range 21.4-44.2). Grade II injury was pathologically diagnosed in 8.3% (1/12) of the ureters in both groups.

CONCLUSIONS

The transduction of ultrasonic longitudinal-axis vibration onto the UAS reduces maximal UASIF and does not harm the ureter. Reducing the velocity of sheath insertion may further reduce maximal UASIF.

Fiberoptic versus Digital: A Comparison of Durability and Cost Effectiveness of the Two Flexible Ureteroscopes

AIMS

We aimed to evaluate the durability and cost effectiveness of the latest digital flexible ureterescope by comparing it with the conventional fiberoptic one.

MATERIALS AND METHODS

Data of patients who underwent retrograde intrarenal surgery between January 2013 and December 2014 were collected. Fiberoptic Flex-X2 or digital Cobra vision flexible ureteroscopes were used for the procedures. The comparison of both ureteroscopes was performed in terms of patient and stone characteristics, operative outcomes, durability, and cost effectiveness.

RESULTS

A total of 105 patients were evaluated for the study. The patient and stone characteristics and operative outcomes were similar between the groups. Overall, 54 and 51 procedures were performed using Flex-X2 and Cobra vision, respectively, before they were sent for renovation. The purchase prices were USD 29,500 for Flex-X2 and USD 58,000 for Cobra vision. Costs of per case were determined as USD 549.29 for Flex-X2 and as USD 1,137.25 for Cobra vision. Per minute working time costs were USD 772.04 and 1,471.33 for Flex-X2 and Cobra vision respectively.

CONCLUSIONS

The digital Cobra vision has high costs without any difference in durability as compared to Flex-X2. Moreover, it has no benefit over Flex-X2 in terms of surgical outcomes.

A New Automatically Fixating Stone Basket (2.5 F) Prototype with a Nitinol Spring for Accurate Ureteroscopic Stone Size Measurement

Introduction

Intraoperative assessment of stone size is crucial for the successful and safe extraction of stones. The first automatically fixating measuring stone basket prototype showed a mismatch between the steel spring and the nitinol basket; therefore, to improve this prototype, the steel spring was replaced with a nitinol spring and a modified scale was implemented on the basket handle for accurate intraoperative stone size measurement.

Methods

The proposed tipped basket was composed of nitinol. A standard handle with a spring-supported self-closing mechanism (2.5 F, Urotech^®) was used, and a modified nonlinear millimeter scale was established on the handle. The grasping force was provided by the new nitinol spring mechanism in the handgrip. Various colors associated with the stone size were applied on the scale.

Results

The material difference between the basket and the spring was eliminated. The measuring scale ranged from 2 mm (green) through 5 mm (yellow) to 8 mm (red), and the scale was nonlinear because of the nonlinear relationship between the diameter of the stone and the distance marked on the scale.

Conclusion

The proposed automatically fixating stone basket with a nitinol spring has the potential to improve the safety and effectiveness of endourological stone retrieval. Further validation of this new scale and basket should follow.

Miniature ureteroscope distal tip designs for potential use in thulium fiber laser lithotripsy

Thulium fiber laser lithotripsy using smaller optical fibers may enable development of miniature ureteroscopes. Two ureteroscope distal tip prototypes were built and characterized. The first design was 4.5-French (Fr) [1.5-mm outer diameter (OD)], five channel tip, housing 200-μm inner diameter (ID) dedicated central channel for insertion of 100-μm core fibers and four surrounding channels, each with 1.5 Fr (510-μm ID) for instrumentation, irrigation, imaging, and illumination, respectively. The second design was 6.0-Fr (2.0-mm OD), three-dimensional printed tip with larger, hemispherical common working channel and separate detection port integrated with ring lighting. Standard instruments, including optical fibers, guidewires, and stone baskets, were inserted through working channels to demonstrate feasibility. Gravitational and manual pump-assisted saline irrigation rates were measured. Luminous intensity distribution curves (LIDCs) were modeled for both ring and conventional lighting designs. Imaging was conducted using 3000, 6000, and 10,000 pixel, miniature, flexible endoscopes with 0.4-, 0.6-, and 0.9-mm OD, to differentiate between urinary stones and ureter wall, for potential clinical application. The multichannel ureteroscope tip with 1.5-Fr working channel yielded a gravitational saline flow rate of 3.9  ±  0.2  mL  /  min compared to 31.3  ±  0.6  mL  /  min for standard (3.6 Fr) ureteroscope channel. Manual, pump-assisted irrigation increased flow rate to 32.5  ±  3.0  mL  /  min. The 6000 pixel, 0.6-mm OD, flexible endoscope provided a balance of clear differentiation between stones and ureter wall and sufficiently small OD. A ring lighting configuration provided more uniform illumination than conventional cross-lighting geometry as demonstrated by LIDCs. With further development, these miniature ureteroscope tip designs may be integrated into a fully functional ureteroscope to permit ureteral access with minimal trauma and improved patient safety and comfort.

Efficacy analysis of self-help position therapy after holmium laser lithotripsy via flexible ureteroscopy

BACKGROUND

To observe the efficacy of self-help position therapy (SHPT) after holmium laser lithotripsy via flexible ureteroscopy (FURS).

METHODS

From January 2010 to November 2015, 736 nephrolithiasis patients who had received FURS lithotripsy were analyzed retrospectively. In position group, 220 cases accepted SHPT after lithotripsies, and 428 cases as control, coming from another independent inpatient area in the same center. The stone-free status (SFS) between two groups were compared at the 2nd, 4th and 12th week ends by X-ray examinations.

RESULTS

The preoperative incidence of hydronephrosis (25.9% vs. 18.0%, p = 0.018) or lower calyceal seeper (33.6% vs. 24.3%, p = 0.012) and the proportion of patients with > 2.0 cm stones (33.6% vs. 24.3%, p = 0.003) were all significantly higher in position group than in control group. There were no substantial difference between two groups in age, BMI, gender and medical histories. In postoperative followup, the incidence of hydronephrosis in position group was significantly lower than in control group (9.5% vs. 15.7%, p = 0.032) after removing double-J stents. In position group, the SFS of the 2nd week end (60.9% vs. 47.2%, p = 0.001), the 4th week end (74.1% vs. 62.8%, p = 0.004) and the 12th week end (86.9% vs. 79.4%, p = 0.021) were all significantly higher than those in control group.

CONCLUSIONS

SHPT after holmium laser lithotripsy via FURS may increase postoperative SFS, accelerate stone fragment clearance, and decrease the incidence of hydronephrosis after removal of double-J stents. The therapy does not require professional assistance and is economical, simple, and effective.

[Initial experience in clinical application of thulium laser contact lithotripsy for transurethral treatment of urolithiasis]

INTRODUCTION

The choice of an effective and safe method of disintegration of stones in upper and lower urinary tract is very important in the context of continuous scientific and technological progress. In current clinical urological practice, various lithotriptors with rigid and flexible probes are used for contact disintegration of stones, having both advantages and disadvantages. This study aimed to analyze the first results of the clinical application of the native Tm: fiber Urolaz laser (STA IRE-Polyus, Russia) for contact transurethral lithotripsy.

MATERIALS AND METHODS

The study comprised 56 patients who underwent transurethral contact thulium laser lithotripsy for 68 stones of the upper and lower urinary tracts between April and September 2017. Forty-four patients had kidney and ureteral stones, and twelve patients had urinary bladder stones. Twenty-four kidney stones were removed by retrograde intrarenal surgery using ureteral casing, flexible ureteropyeloscope and thulium laser, 32 stones in various ureteral segments - by rigid contact thulium laser ureterolithotripsy and 12 bladder stones - by thulium laser cystolithotripsy. The size of the upper urinary tract stones varied from 0.6 to 1.8 cm, bladder stones measured from 1.1 to 3.5 cm. Also, experimental studies were carried out to investigate the effects of the fiber thulium and holmium laser on the stone displacement and temperature environment during lithotripsy.

RESULTS

Full stone fragmentation was achieved in 100% of patients. 47.7% of patients required additional lithoextraction of fragments; there was no retrograde migration of large stones. The mean duration of stone disintegration was 19 minutes. Postoperatively, 15.9% of patients had an exacerbation of pyelonephritis, which was successfully managed by conservative measures. The mean postoperative hospital stay was 2.4+/-1.1 days. At follow-up examination 4-6 weeks after surgery, one patient was found to have a residual symptomatic ureteral stone, which required extracorporeal short-wave lithotripsy. The experimental study showed that fiber thulium laser lithotripsy produced much less propulsion of artificial stone than Holmium laser lithotripsy. With the use of therapeutic power, neither of the lasers resulted in "dangerous" rises of the washing fluid temperature during stone disintegration.

CONCLUSION

Using the universal thulium laser system "Urolaz" provides a significant improvement in the effectiveness of endourologic upper urinary tract interventions and significantly reduces the likelihood of intraoperative trauma and postoperative complications, which contributes to improving the quality of specialized urological care.

Ureteroscopy from the recent past to the near future

Stone surgery is one of oldest surgical practices undertaken by man. Hippocrates refused to let his followers "cut for the stone" and it was only in February 1980, when the first human trial of shock wave therapy on a renal stone was performed with success that a new era in minimally invasive treatment (surgery) for stones was opened up and this condemnation was finally resolved in the Hippocratic Oath. Endoscopy, using natural orifices, supported by anaesthesia, incremented by technology and with access to all points along the urinary tract, began by competing with ESWL, but is now the treatment of choice in most cases. As far as we know humans have always had stones. First, lithiasis was endemic bladder stones in children, now it is renal in general. Added to this a number of well-known risk factors, a rapid increase in obesity in the population, as well as bariatric surgery for its treatment, are causing an increase in the prevalence and recurrence of lithiasis everywhere. A short history of the advances made with the introduction and development of the ureteroscope, along with auxiliary devices, will show why this is the preferred technique at the moment for treating lithiasis in general and for treating stones in pregnant women, children and the obese in particular. Being a minimally invasive surgery, with a low morbidity and a very high efficiency and stonefree rate, has become established as a clear future technique for both adults and children. This development is not only due to technological advancements, but also to the routine use of the Holmium: YAG LASER for intracorporeal lithotripsy, capable of destroying any stone regardless of its composition or location, surpassing the ability of any other lithotripter. It is also due to the development of devices that allow access to the ureter and all parts of the kidney, as well as auxiliary aids to assist in the handling of stones during treatment. New LASERs, robotic control of the fdURS and digital imaging, as well as disposable devices, have had and, indeed, continue to have a unique impact on future development in this field. However, success will continue to depend on the careful choice of fURS, energy source and ancillary instruments obtained by the urologist during both real life and virtual training in human simulators.

Single-use flexible ureteropyeloscopy: a systematic review

PURPOSE

Data assessing the effectiveness of single-use flexible ureteropyeloscopy (FURS) are limited. This study evaluates and compares single-use FURS with conventional reusable FURS.

METHODS

A systematic search using electronic databases (Pubmed and Embase) was performed for studies evaluating single-use FURS in the setting of urinary tract stone disease. Outcome measures included a comparative evaluation of their mechanical, optical and clinical outcomes.

RESULTS

Eleven studies on 466 patients met inclusion criteria. In vitro comparative data were available on three single-use flexible ureteropyeloscopes (LithoVue™, Polyscope™ and SemiFlex™) and clinical data were available on two (LithoVue™ and Polyscope™). The overall stone-free rate and complication rate associated with single-use FURS was 87 ± 15% and 9.3 ± 9%, respectively. There were no significant differences in procedure duration, stone size, stone clearance and complication rates when single-use FURS and reusable FURS were compared (duration: 73 ± 27 versus 74 ± 13 min, p = 0.99; stone size: 1.36 ± 0.2 versus 1.34 ± 0.18 cm, p = 0.93; stone-free rate: 77.8 ± 18 versus 68.5 ± 33%, p = 0.76; complication rate 15.3 ± 10.6 versus 15 ± 1.6%, p = 0.3).

CONCLUSIONS

Single-use FURS demonstrates comparable efficacy with reusable FURS in treating renal calculi. Further studies on clinical efficacy and cost are needed to determine whether single-use FURS will reliably replace its reusable counterpart.

A pilot study evaluating changes to haematological and biochemical tests after Flexible Ureterorenoscopy for the treatment of kidney stones

BACKGROUND

Currently there is limited research documenting the changes in blood parameters, following Flexible Ureterorenoscopy. This study aims to determine whether there are any changes in haematology and biochemistry parameters, following Flexible Ureterorenoscopy for the treatment of kidney stones.

METHODS

40 consecutive patients aged between 27-87 years (median 49 years) undergoing Flexible Ureterorenoscopy for the treatment of kidney stones were recruited (26 male, 14 female). Blood samples were collected from each patient at four time points: baseline (pre-operatively) followed by 30 minutes, 120 minutes and 240 minutes post-operatively. On these samples, routine haematological and biochemistry tests were carried out. In addition to the assessment of clinical parameters prospectively from the medical notes.

RESULTS

There was a significant decrease observed following Flexible Ureterorenoscopy in the following parameters: lymphocytes (p = 0.007), eosinophils (p = 0.001), basophils (p = 0.001), haemoglobin (p = 0.002), red blood cells (p = 0.001), platelet count (p = 0.001), fibrinogen concentration (p = 0.001), von Willebrand factor (p = 0.046), C reactive protein (p = 0.01), total protein (p = 0.001), albumin (p = 0.001), globulin (p = 0.001) and alkaline phosphatase (p = 0.001). In addition, there was a significant increase observed in the following parameters: white blood cells (p = 0.001), neutrophils (p = 0.001), activated partial thromboplastin time (p = 0.001), total bilirubin (p = 0.012), creatinine (p = 0.008), sodium (p = 0.002) and potassium (p = 0.001). Limiting factors for this study were the sample size, and restriction on the recruitment time points.

CONCLUSIONS

Significant changes were noted to occur in haematology and biochemistry parameters following Flexible Ureterorenoscopy. Some of the data presented in this study may represent the 'normal' post-operative response following FURS, as no major complications occurred, in the majority of our patients. This data on the 'normal response' will need to be validated but may ultimately aid clinicians in distinguishing patients at risk of complications, if reproduced in larger multi-centre studies.

From novelty to the every-day: the evolution of ureteroscopy

Ureteroscopy revolutionized the surgical approach to the upper urinary tract, and is well recognized as a cornerstone of modern urology. Although now commonplace, ureteroscopic equipment and techniques were truly revolutionary. A review of the innovations and innovators that developed ureteroscopic surgery sets the stage for a more thorough understanding of what can be done ureteroscopically, and may additionally better inform what limitations remain. Given that future advancements in urologic therapy will be dependent upon a similar pursuit of paradigm shifting improvements in disease management, an overview of the development of modern ureteroscopy may inspire such change.

Ureteroscopy: accessory devices

The incidence of stone disease continues to rise. Surgical management options including shockwave laser lithotripsy, percutaneous nephrolithotomy, and ureteroscopy with stone extraction and/or lithotripsy. The technology associated with the ureteroscopic treatment of stones has advanced significantly over the past decade and this review focuses on many of the accessory devices that can be employed to aid in the procedure.

The future of ureteroscopy

Open ureterolithotomy and pyelolithotomy used to be first line therapy for treating kidney and ureteral stones. With the advent of shockwave lithotripsy, open stone surgery became less prevalent, but once ureteroscopy became more prevalent, open stone surgery became all but extinct. Advances in smaller, more flexible endoscopes and improvements in intracorporeal lithotripters, ureteroscopy has become a mainstay of therapy for kidney stones. The holmium:yttrium-aluminium-garnet laser can be utilized through flexible instruments and fragments any stone no matter what it is composed of. Digital image ureteroscopes with chip-on-the-tip technology has improved our visualization during ureteroscopy. What is next? We examine potential directions from current research. Pharmacologic manipulation for ureteral dilation may obviate the need for pre-stenting or balloon dilation. Advances in ureteroscope technology will likely see the biggest advances. Different ureteroscopic platforms and the user interface with the surgeon will progress. Robotic manipulation of the endoscope is an eventual reality with improved ergonomics and improved performance to reach all areas of the kidney. Single-use ureteroscopes are already a reality and offer a digital image with full deflection with every use and without having to worry about sterilization and costly repairs. Lastly, advancements in nanotechnology and robotics will see the potential for miniaturized robots that could be administered intravesically to identify the stone and to disintegrate it. The only prediction that can be made about the future of ureteroscopy is that we do not know how it will look. The future of ureteroscopy is exciting and most definitely will be unrecognizable to the surgeons of today.

Ureterorenoscopy: current technology and future outlook

The aim of this paper was to evaluate the current technology and designs of flexible ureterorenoscopes. We will review contemporary fiberoptic and digital ureteroscopes, including a discussion on ureteroscope damage and repair, and lastly present the projected future of flexible ureterorenoscopy. Ureterorenoscopy has evolved dramatically over the past several decades, which has led to landscape reshaping of stone disease treatment and upper tract pathology. Advancements in tip control, miniaturization of scopes, introduction of a digital chip on the tip, disposable devices to augment surgery, surgical experience/familiarity and most recently single use scopes are all independent factors that have increased flexible ureterorenoscopy adoption and success. We therefore detail the aforementioned and provide a view of future innovations. A review of literature from 1980 to 2016 was performed by the two authors focusing on literature that details flexible ureterorenoscopy. Technology has significantly impacted the minimally invasive endourologic management of the urinary system. This review summarizes current literature on advances and modern technical achievements. We include a focus on new perspectives and future outlook in the field of managing upper urinary tract pathology with modern technologies. The advancements in flexible ureterorenoscopy are impressive and yet the challenges of this technology are equally daunting. Obstacles to overcome include improving durability, decreasing cost, further miniaturizing scopes size, and determining the role of single use scopes. Ongoing developments in other technology fields (such as virtual 3D imaging, wireless capsular endoscopy, robotics) continue to create both opportunities to improve the procedure but also threaten to replace ureterorenoscopy over time. This is an exciting time because of past achievements and future innovations in ureterorenoscopy.

Robotic Flexible Ureteroscopy Versus Classic Flexible Ureteroscopy in Renal Stones: the Initial Romanian Experience

INTRODUCTION

Roboflex Avicenna represents a new device for flexible ureteroscopy, able to provide an efficient lithotripsy for renal calculi, Bucharest being the fourth place in the world where such a device is already in use.

MATERIAL AND METHODS

The study was prospective and included a number of 132 patients equally randomized which underwent standard flexible ureteroscopy and robotic flexible ureteroscopy for renal calculi between July and February 2016. All the procedures were performed with aStorz XC flexible ureteroscope in association with Avicenna Roboflex. Stone fragmentation was performed using a Dornier Medilas 20H, Holmium Laser of 20 watt power and 2.1 µm wavelength.

RESULTS

The mean age was 48 years (range 26-77 years) and the mean stone size was 2.1 cm (range 1.1-3.6 cm) for the first group (FURS), while for the second one (robotic FURS) the mean age was 51 years (range 25-74 years) and the mean stone size was 2.4 cm (range 1.0-3.7 cm). The fragmentation time of the stones was better for robotic FURS (37 min versus 39 min). After 3 months, the stone free rate was 89.4% versus 92.4%, that representing a performance of the robotic technique over the classical one. In some cases were noticed residual fragments smaller than 3 mm, in 13.6% of patients who underwent FURS, respectively in 12.1% of robotic FURS™ cases.

CONCLUSIONS

The robotic treatment of kidney stones represents a comparative alternative to flexible ureteroscopy, with overall similar outcomes.

Ureteric stents on extraction strings: a systematic review of literature

Short-term ureteric stents are commonly placed after ureteroscopy. The removal usually entails having a cystoscopy, but recently, endourologists have been using stents with extraction strings attached to them for ease of removal. We wanted to conduct a systematic review of literature looking at the outcomes of ureteric stents with extraction strings attached to them. Our objective was to investigate the use, morbidity, tolerability, complications, associated cost, and patient preference of stents with extraction strings attached to them. All studies in English language (between 1990 and 2015) where stents on extraction strings were either self-removed by patients or removed by physician were included. A total of eight studies (1279 patients) were included, of which 483 (38 %) patients had extraction strings for removal. There seemed to be no overall difference in pain scores or urinary symptoms between patients with and without extraction strings, but nearly 10 % of patients suffered stent dislodgement in the group with extraction strings attached. Overall stent dwell time was lower in patients who had their stents removed via extraction strings, and majority of them were able to remove their stents at home. Our study suggests that stents with extraction strings are easy for patient self-removal and can reduce the stent dwell time for patients, thus reducing the duration of morbidity and physical and financial burden to patients. However, this must be balanced against a risk of stent dislodgement and, hence, may not be a good option in all patients.

Comparison of Flexible Ureterorenoscopy and Laparoscopic Ureterolithotomy Methods for Proximal Ureteric Stones Greater Than 10 mm

OBJECTIVE

To examine the outcomes and to compare the effectiveness of laparoscopic ureterolithotomy and flexible URS in patients with proximal ureteral stones greater than 10 mm in diameter.

MATERIAL AND METHODS

A total of 150 patients who were performed laparoscopic ureterolithotomy and flexible URS because of uretral stones in our urology clinic between January 2010 and June 2015, were analyzed retrospectively. We constituted two groups; 70 patients who were performed laparoscopic ureterolithotomy were included in group I while flexible URS-performed 80 patients in group II. Success rates and complications of the group I and II were compared.

RESULTS

Success rates were 95.7% and 90% in group I and II respectively. There was no significant difference between the groups in terms of "success-rates". No statistically and clinically significant complications occurred in both groups.

CONCLUSION

Laparoscopic ureterolithotomy and flexible URS methods are effective and reliable with proper indications in treatment of proximal ureteral stones. However, when considered short operational and hospitalization times and the management of the situations that require secondary interventions, we suggest that flexible URS is a minimally invasive method and it may be the first choice in the treatment of proximal ureteral stones.

Wild-type ATTR amyloidosis of the ureter in a 56-year-old woman with rheumatoid arthritis and Sjögren's syndrome

We present a case of acute pyelonephritis with right hydronephrosis in a middle-aged woman, who had suffered from rheumatoid arthritis and Sjögren's syndrome. She had successfully treated with antibiotics, however, ureteral stenosis sustained. She underwent ureteroscopy and stenting of right ureter. Biopsy specimen revealed submucosal amyloid deposition in the interstitium overlying a benign urothelium. Amyloid protein was positive for transthyretin (TTR) by immunohistochemistry and amyloid deposition was not demonstrated in other organs. The patient's TTR genes were wild type and she was diagnosed with wild-type ATTR (ATTR wt) amyloidosis. This is the first report about symptomatic ATTR wt amyloidosis, which was also called 'systemic senile amyloidosis (SSA)' in the ureter. We should aware that SSA can occur at younger age and cause symptomatic ureteral stenosis. Further investigation is needed to clarify the association of autoimmune diseases to develop ATTR wt amyloidosis.

Comparison of flexible ureterorenoscopy and micropercutaneous nephrolithotomy in the treatment for moderately size lower-pole stones

PURPOSE

To present a retrospective comparative clinical study of micropercutaneous nephrolithotomy (microperc) versus flexible ureterorenoscopy (F-URS) in treatment of moderate-size lower-pole stones (LPSs).

METHODS

We retrospectively reviewed data on patients with isolated LPSs ≤2 cm in diameter treated with F-URS and/or microperc in two referral centers. Patients were divided into two groups by treatment modality: F-URS (Group 1) and microperc (Group 2). Demographics and perioperative parameters were analyzed.

RESULTS

A total of 127 patients with isolated LPSs were treated via F-URS (Group 1, n = 59) and microperc (Group 2, n = 68). Mean patient age in microperc group was slightly lower than in F-URS group (p = 0.112). We found no statistically significant difference in terms of either the size or number of stones in two groups (p = 0.113 and p = 0.209, respectively). Operative time was shorter in microperc, whereas fluoroscopy time was shorter in F-URS (60.1 ± 26.2 vs. 46.2 ± 24.3 min, p < 0.001; and 28.3 ± 19.1 vs. 108.9 ± 65.2 s, p < 0.001). Mean fall in hemoglobin level was statistically significantly lower in F-URS and hospitalization time was also significantly shorter in F-URS (0.68 ± 0.51 vs. 1.29 ± 0.88 mg/dL, p < 0.001; and 23.0 ± 58.1 vs. 33.8 ± 17.2 h, p < 0.001, respectively). Stone-free rates (SFRs) were 74.5 % (44/59) in Group 1 and 88.2 % (60/68) in Group 2 (p < 0.001).

CONCLUSIONS

We found that microperc was safe and efficacious when used to treat moderate-size LPSs and may be considered as an alternative to F-URS, affording a higher SFR. Our study supports the notion that microperc should play an increasing role in treatment of LPSs.

New ureteral access sheaths: a double standard

OBJECTIVE

To investigate the functional characteristics of the traditional and new single-wire ureteral access sheath (UAS) configurations relating to insertion, positioning, tissue injury, and durability.

MATERIALS AND METHODS

Four UAS were tested: Navigator HD (11/13F, Boston Scientific), Re-Trace (10/12F, Coloplast), Flexor-Parallel (P), and Flexor-Regular (R; 9.5/11.5F, Cook Medical). UASs were evaluated for sharpness-(1) foil perforation, (2) tissue skiving (advancing sheath/dilator against fixed foil or bologna models); rigidity-(3) tip bending, (4) sheath buckling; (5) lubricity (dynamic friction through bologna), (6) dilator removal force, (7) kinking forces (side wall compressive forces), and (8) radiopacity. New UASs were used for each trial. A motorized sliding stage was used, and continuous force measurements were recorded with a Mark-10 digital force gauge.

RESULTS

The Navigator HD had the largest external diameter (13.02F). Re-Trace had the longest (51 mm) and most flexible tip (0.942 lb, P <.001). Flexor-R had the shortest (23.2 mm) and stiffest tip (7.48 lb). The Cook tip perforation forces were highest (0.807 lb), whereas the sheath required the most force (0.25 lb, P <.001) and caused the least damage (4.95 mm) when advanced against tissue. Navigator HD had the least frictional resistance (0.14 lb, P <.001). The single-wire systems had the lowest buckling forces (Navigator HD, 0.41 lb; Flexor-R, 0.827 lb; Flexor-P, 0.445 lb; Re-Trace, 1.014 lb; P <.001) and the highest dilator removal forces compared with classic systems (Flexor-P, 1.39 lb; Re-Trace, 1.9 lb; Navigator HD, 0.190 lb; Flexor-R, 0.194 lb; P <.001). The differences in kinking forces and radiopacity were not significant.

CONCLUSION

The Navigator HD was the most slippery and rigid sheath, whereas the single-wire systems had lower buckling forces and required more force to remove their dilators. Cook sheaths appeared the least traumatic.

Flexible ureterorenoscopy versus semirigid ureteroscopy for the treatment of proximal ureteral stones: a retrospective comparative analysis of 124 patients

PURPOSE

To investigate and compare the stone clearence and complication rates of flexible ureteroscopy (URS) with semirigid URS in patients having proximal ureteral stones.

MATERIALS AND METHODS

The data of 124 patients with proximal ureteral stones who underwent semirigid or flexible ureterorenoscopic lithotripsy between March 2008 and December 2012 were retrospectively investigated. The patients were divided into 2 groups according to the operation types. Group 1 included 63 patients who were treated with semirigid URS and group 2 was consisted from 61 patients who underwent flexible URS. Each group was compared in terms of stone diameter, successful access to the stone, operation time, reoperation rates, stone free status at postoperative 1st and 3rd month and complications.

RESULTS

Successful access was achieved in 48/63 (76%) of the cases in group 1 and 57/61 (93%) of the patients in group 2 (P < .05). Initial stone free status was 63.4% (40/63) and 86.8% (53/61) in groups 1 and 2, respectively (P < .05). Third month radiologic investigations revelaed a stone free rate of 77.7% (49/57) in group 1 and 93.4% (57/61) in group 2 (P < .05). Reoperation was required in 20.6% (13/63) of cases in group 1 and this value was only 6% (4/61) in group 2 (P < .05). There was not any statistically significant difference between 2 groups in terms of complication rates (P > .05).

CONCLUSION

Flexible URS is a favorable option for patients having proximal ureteral stones with higher stone free rate; on the other hand semirigid URS seems a less successful alternative for treatment of proximal ureteral stones.

Ureteroscopy and laser lithotripsy: technologic advancements

Ureteroscopic lithotripsy has evolved since the first reported cases employing rigid rod-lens endoscopes and stiff ultrasonic lithotrites. Fiber optics facilitated rigid endoscope miniaturization and the development of a steerable, deflectable flexible ureteroscopes. Over 30 years of technical innovations culminating in digital imagers and powerful, precise laser lithotrites, complimented by progressive endoscopic techniques have produced efficient endoscopic therapies with minimal morbidity and commonly performed in an outpatient setting.

The use of a ureteral access sheath does not improve stone-free rate after ureteroscopy for upper urinary tract stones

PURPOSE

To evaluate the impact of a ureteral access sheath (UAS) on stone-free (SF) rate after flexible ureteroscopy for upper urinary tract stones.

MATERIALS AND METHODS

We retrospectively reviewed 280 patients who underwent flexible ureteroscopy (URS) for upper urinary tract stone between 2009 and 2012. Patients were divided into two groups based on whether a UAS was used (n = 157) or not (n = 123). SF rate was evaluated at one and three months after surgery by abdominal imaging. Quantitative and qualitative variables were compared with Student's t test and χ2 test, respectively. A logistic regression model was used to determine the predictive factors of SF status.

RESULTS

Stone size was similar in both groups (15.1 vs. 13.7 mm, p = 0.21). SF rates at one and 3 months were comparable in UAS and non-UAS groups (76 vs. 78% and 86 vs. 87%, p = 0.88 and 0.89, respectively). Complication rates were similar in both groups (12.7 vs. 12.1%, p = 0.78). In multivariable analysis, stone size was the only predictive factor of SF rate (p = 0.016).

CONCLUSION

The routine use of a UAS did not improve SF rate in patients undergoing flexible URS for upper urinary tract calculi.

Retrograde intrarenal surgery in Nepal: an early experience

With the advancement in technology and miniaturization of instruments, retrograde intrarenal surgery (RIRS) with flexible ureteroscope is gaining popularity. Flexible ureteroscope is introduced into renal collecting system through the urethra. Holmium YAG (Ho-YAG) Laser fiber of different sizes is introduced through the ureteroscope and renal stones are pulverized. Removal of renal stones less than 15 mm in size with RIRS has sharply reduced post operative morbidity. This is a Prospective study comprised of 58 RIRS performed from January 2013 to July 2013. Preoperative investigations like full blood count (FBC), renal function test (RFT), serological investigations, urine culture, intravenous urogram or CT-urogram, chest ray and electrocardiogram were done in all patients. Renal stones less than 15 mm in size were included for RIRS. Intra renal stones were treated with 7.5 Fr flexible ureteroscope (Flex - X2) using Holmium-YAG laser. Mean stone burden in our study was 10.5 +/- 3.3 mm. Out of 32 male patients, 29 (90.6%) required pre-stenting before RIRS and all 58 patients with successful dusting of stones in single sitting were discharged on next day. Retrograde Intrarenal Surgery is advanced and successful technique and a viable alternative to Extracorporeal Shock Wave Lithotripsy (ESWL) and Percutaneous Nephrolithotomy (PCNL) in the treatment of selected intrarenal stones with minimum morbidity.

[Endoscopic methods for the correction of ureteral strictures]

The comprehensive examination and treatment of 80 patients aged 19 to 63 years with strictures of the ureteropelvic junction (UPJ) and ureter obstruction was performed. 23 patients underwent probing with ureteral stenting, 30 patients underwent balloon dilation of strictures under fluoroscopic guidance, 18 patients--endoureteropielotomy with "cold" knife, 9 patients underwent endoureteropielotomy using holmium laser. Correction of ureteral stricture with the removal of the stone was performed in 6 patients. It was found that efficiency of the methods increases in the following order: balloon dilatation (73.3%), dissection using "cold" knife (77.8%), probing with ureteral stenting (82.6%), and laser endoureteropielotomy (100%). In general, endoscopic correction of ureteral contractions is a minimally invasive treatment option for restoring its continuity, without perfoming traumatic surgery in 80% of patients with UPJ and ureteral strictures, including complicated by stone formation.

Ureteroscopic management of chronic unilateral hematuria: a single-center experience over 22 years

Objective

To analyze the short and long term safety and efficacy of ureteroscopic evaluation and management of chronic unilateral hematuria.

Methods

We retrospectively reviewed patients with chronic unilateral hematuria from 1987 to 2008. The distal to middle ureter was evaluated with a semi-rigid ureteroscope without a guidewire. Subsequently, the flexible ureteroscope was advanced into the upper ureter to the renal pelvis using a low-pressure automated irrigant system (Uromat™). Lesions identified ureteroscopically were treated with diathermy fulguration.

Results

One hundred and four (56 male, 48 female) patients were identified, with a median age of 37 (14–80) years and median follow-up of 139 (34–277) months. The median preoperative duration of gross hematuria was 5 (1–144) months. Endoscopic findings included 61 (56%) minute venous rupture (MVR; a venous bleeding without clear abnormalities), 21 (20%) hemangioma (vascular tumor-like structure), 3 (3%) varix (tortuous vein), 1 (1%) calculus and 18 (17%) no lesions. The incidence of “no lesions” was less in the recent 12 years (9%) than the first 10 years (27%), while the incidence of MVR increased from 40 to 66% (p<0.05). All patients were treated endoscopically. Immediate success rate was 96% (100% in the recent 12 years). Long-term recurrent gross hematuria rate was 7%. Six resolved spontaneously and only 1 required ureteroscopy, revealing a different bleeding site.

Conclusion

Ureteroscopy and diathermy fulguration is highly useful for evaluation and treatment of chronic unilateral hematuria. Sophisticated technique and improved instrumentation contributes to a better outcome.

An innovative combined antero-retrograde approach for the resolution of the complete iatrogenic obliteration of ureteral ostium: a case report

In selected cases of endoscopic surgery of bladder cancer, in order to reach an oncologic radicality, the resection of the ureteral ostium affected by the disease is required. Although infrequent, a possible complication of this manoeuvre is represented by the complete obliteration of theresected ostium. Literature suggests that the traditional "open" surgery and the latest "laparoscopic" surgery are effective in the resolution of this complication, in contrast with the techniques of endourological and uro-interventional radiology which, although minimally invasive, do not appear to be completely appropriate in the treatment of this condition. We believe that an innovative, minimally invasive anterograde trans-nephrostomic and retrograde endoscopic combined approach can be decisive in restoring complete patency of the neo-ostium.

Flexible ureterorenoscopy versus miniaturized PNL for solitary renal calculi of 10-30 mm size

INTRODUCTION

The value of flexible ureterorenoscopy (fURS) and miniaturized PNL (mPNL) for larger renal calculi is under discussion. This non-randomized prospective study aimed to evaluate fURS and mPNL for solitary renal stones of 10-30 mm size.

MATERIALS AND METHODS

fURS was carried out in 21 patients with last generation 7.5F endoscopes. Ureteral access sheaths were used in 19 patients. For mPNL, an 18F modified Amplatz sheath with a 14F nephroscope were used (n = 25). The procedure was performed either tubeless with an antegrade stent or a nephrostomy. Outcome and complications of both procedures were assessed.

RESULTS

Patients' demographics and stone sizes were comparable (18 ± 5 vs. 19 ± 4 mm, P = 0.08). Patients in the fURS group had a higher mean BMI (31 vs. 27, P < 0.05). Total OR time was significantly longer for fURS (106 ± 51 vs. 59 ± 19 min., P < 0.001). More patients were stone-free after one single percutaneous treatment, while 2nd-stage treatments with fURS were common (total procedures 1.04 vs. 1.52, P < 0.001; immediate stone-free rate (SFR) 96% vs. 71.5%, P < 0.001). SFR after 4 weeks was 100% (mPNL) and 85.8% (fURS) (P < 0.01). Minor complications as classified by Clavien I or II occurred in 16 and 23.8%, mPNL and fURS, respectively, P = 0.13). No major complications (Clavien III-V) occured in both groups.

CONCLUSIONS

Our series supports both the concept of either percutaneous or retrograde endoscopic treatment for renal calculi with both modalities offering excellent safety. However, while for fURS, a significantly higher rate of 2nd-stage procedures was necessary, and mPNL led to faster and higher SFR without increasing complication rate.

Rare case of ureteral endometriosis presenting as hydronephrotic kidney

A 29-year-old woman presented with unilateral loin pain because of severely hydro-nephrotic kidney due to deposits of pelvic endometriosis. Double J-stent was placed beyond the obstruction and she was started on hormone therapy. The stent was removed after three months when back pressure changes had resolved. This case is being presented along with a short relevant discussion, due to rarity of ureteral involvement by endometriosis.