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.

Impacto del uso de la vaina de acceso ureteral durante la ureteroscopia flexible: estudio comparativo de eficacia y seguridad / Impact of ureteric access sheath use during flexible ureteroscopy: A comparative study on efficacy and safety

Objetivos Este estudio evalúa el impacto del uso de una vaina de acceso ureteral (VAU) durante la ureteroscopia flexible (URSf) para el tratamiento de la litiasis urinaria, centrándose en resultados como la tasa libre de litiasis, el tiempo quirúrgico y las complicaciones. Métodos Este estudio prospectivo y aleatorizado se llevó a cabo en el Hospital de Badr en la Universidad de Helwan y en los hospitales de la Universidad de Ain Shams, desde agosto de 2021 hasta agosto de 2022. Los pacientes se aleatorizaron sistemáticamente a 2 grupos (URSf con VAU: 33 pacientes y URSf sin VAU: 31 pacientes), y se sometieron a evaluaciones preoperatorias y postoperatorias, incluyendo pruebas de laboratorio y de imagen. Se controlaron los posibles riesgos asociados al procedimiento, como el fracaso en el acceso al cálculo, el dolor, el sangrado y la sepsis. Resultados Se observó que los 2 grupos eran comparables en cuanto a características demográficas o hallazgos preoperatorios de la litiasis (p>0,05 para todos). Sin embargo, el tiempo quirúrgico fue menor en el grupo tratado sin VAU (79,4±15,3 vs. 90,4±16,7min en el grupo tratado con VAU; p=0,008). Las tasas de complicaciones intraoperatorias, incluidos el fracaso del acceso, la interrupción de la operación, las lesiones ureterales y el sangrado, fueron comparables en ambos grupos (p>0,05). No se observaron diferencias significativas en cuanto a la tasa libre de litiasis postoperatoria (78,8 vs. 71,0%; p=0,305) y el tamaño litiásico residual medio (2,7±3,5 vs. 3,1±3,1mm; p=0,687). Conclusiones El presente estudio sugiere que URSf sin VAU puede ofrecer una opción eficiente e igualmente efectiva para el tratamiento de los cálculos renales y de uréter superior. Sin embargo, se necesitan más estudios con muestras de mayor tamaño y periodos de seguimiento más largos para validar estos resultados y establecer indicaciones más precisas para este procedimiento. (AU)

Objectives This study evaluates the impact of using an access sheath (AS) during flexible ureteroscopy (fURS) for urolithiasis treatment, focusing on outcomes such as stone-free rate, operation time, and complications. Methods This prospective, randomized study was carried out at Badr Hospital, Helwan University, and Ain Shams University hospitals from August 2021 to August 2022. Patients were systematically randomized into two groups (fURS with AS: 33 patients and without AS: 31 patients) and underwent preoperative and postoperative assessments, including lab tests and imaging. Possible procedure-associated risks, such as failed stone access, pain, bleeding, and sepsis, were monitored. Results The two groups were found to be comparable in terms of demographic characteristics or preoperative stone findings (P>.05 for all). However, operation duration was shorter in the No Sheath group (79.4±15.3minutes vs. 90.4±16.7minutes in the Sheath group, P=.008). Intraoperative complication rates, including failed access, operation termination, ureteric injury, and bleeding, were comparable in both groups (P>.05). Postoperative stone-free rates (78.8% vs. 71.0%, P=.305) and mean residual stone size (2.7±3.5mm vs. 3.1±3.1mm, P=.687) showed no significant differences. Conclusions The present study suggests that fURS without an access sheath may offer an efficient and equally effective option for managing upper ureteric and renal stones. However, more studies with larger sample sizes and longer follow-up periods are required to validate these findings and to establish more precise indications for this approach. (AU)

Rigid ureteroscopic lithotripsy in the lateral decubitus position for upper urinary tract stones.

BACKGROUND: The current study aimed to assess a novel ureteroscopic technique developed for treating upper urinary calculi based on a specially designed lateral decubitus body position that could avoid stone loss by adjusting to the effects of gravity. METHODS: This retrospective study examined patients with upper urinary calculi who were surgically treated from November 2008 to January 2020, using a new body position and a rigid ureteroscope. Clinical outcomes, stone-free rates, operative times and complications were evaluated, and factors that could influence treatment success were determined. RESULTS: In total, 1080 patients were included, and 1145 operations were performed. The maximum calculus diameters were 11.22 ± 5.01 mm. Operative times were 48.60 ± 27.44 min. A total of 1042 cases were successfully treated, with a stone-free rate of 91.00%. Multivariate analysis showed that female sex (OR = 2.135, 95% CI 1.332-3.422, P = 0.002), thin scope standby (OR = 1.643, 95% CI 1.074-2.514, P = 0.022), laser lithotripsy (OR = 5.087, 95% CI 2.400-10.785, P = 0.000) and stone size (OR = 0.946, 95% CI 0.912-0.981, P = 0.003) were independently associated with stone-free outcomes. In total, 2 ureteral perforations, 2 ureteric avulsions and 4 urosepsis cases were observed, but were all cured without sequelae. CONCLUSIONS: Ureteroscopic lithotripsy in the lateral decubitus position is a safe and effective technique for treating upper urinary tract calculi, especially upper ureteral calculi.

The Life and Death of Percutaneous Stone Removal: "Looking Back-Looking Forward".

Although percutaneous nephrolithotomy (PCNL) is less morbid than open surgery, it still carries risks of significant complications as well as injury to the renal parenchyma. Flexible ureteroscopic stone removal, although causes no appreciable damage to the renal parenchyma, has limitations, most notably, a lower stone-free rate than PCNL. Advances in our knowledge regarding ureteral physiology combined with technical developments applied to ureteral access sheath deployment and size may well propel retrograde intrarenal surgery to the forefront of kidney stone removal, regardless of stone size or location.

Is Retrograde Intrarenal Surgery as Safe for Children as It Is for Adults?

INTRODUCTION: The primary aim of this study is to compare the efficacy and safety of retrograde intrarenal surgery (RIRS) among the children and adults with similar stone burdens and locations. Also, the secondary aim of this study is to identify the factors affecting the stone-free rates (SFRs) of RIRS. METHODS: We retrospectively compared perioperative results, SFRs, and complication rates (CRs) between pediatric (group 1, n: 55) and adult (group 2, n: 220) age groups diagnosed with kidney stones and treated by flexible ureterorenoscopy using the same instruments. Furthermore, multivariate analysis was performed to determine the factors affecting the SFR. RESULTS: A total of 275 patients (pediatric group: 55; adult group: 220) were included in this study. The mean age of pediatric and adult groups was 7.2 ± 5.3 and 43.9 ± 15.1, respectively. The mean stone size was 13.9 ± 6.6 mm in the pediatric group compared to 14.8 ± 6.7 mm in the adult group (p = 0.35). Stone localizations and number were similar. JJ stenting for passive dilatation and use of UAS were higher in the pediatric group (p = 0.002; p = 0.017). However, postoperative double pigtail stenting rate was higher in the adult group (p < 0.001). Total CR was 13.8% and mostly Clavien I-II, and no difference was observed between the 2 groups (p = 0.541). The SFRs between the groups were similar (pediatric group: 81.8%; adult group: 78.2%; p = 0.554). On multivariate analysis, stone size (p < 0.001) and lower calyx stone (p < 0.001) were the negative predictive factors for SFR. CONCLUSION: There are small technical differences between pediatric patients and adult patients in our study, but RIRS in children is as safe and efficient as it is in adults.

How to evaluate a flexible ureterorenoscope? Systematic mapping of existing evaluation methods.

OBJECTIVES: The objective of this study was to identify, map and review scope-related and user-related parameters used to evaluate the quality of flexible ureterorenoscopes. Thereby identifying key items and variability in grading systems. METHODS: A literature search of four databases (MEDLINE [Ovid], EMBASE [Ovid], Web of Science, Google scholar and the Cochrane Library) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines encompassing articles published up to August 2020. A total of 2386 articles were screened. RESULTS: A total of 48 articles were included in this systematic scoping review. All studies had a prospective design. Five key items in the assessment of flexible ureterorenoscopy were distinguished: 'Manoeuvrability' (87.5%), 'Optics' (64.6%), 'Irrigation' (56.3%), 'Handling' (39.6%) and 'Durability' (35.4%). After regrouping, every key item could be divided into specific subcategories. However, the quality assessment showed a wide variation in denomination, method of measurement, circumstances of measurement, tools used during measurements, number of measurements performed, number of observers, and units of outcomes. CONCLUSION: The research field regarding quality assessment of ureterorenoscopes is heterogeneous. In this systematic scoping review we identified five key parameters: Manoeuvrability, Optics, Irrigation, Handling and Durability, used to grade flexible ureterorenoscopes. However, within these categories we found a wide variety in terms of method of measurements. A standardised, uniform grading tool is required to assess and compare the quality of flexible ureterorenoscopes in the future.

The T-Tilt Position: A Novel Modified Patient Position to Improve Stone-Free Rates in Retrograde Intrarenal Surgery.

PURPOSE: Residual fragments following retrograde intrarenal surgery can lead to future stone episodes. The lower pole of the kidney presents a unique challenge as it is the most difficult location for retrograde intrarenal surgery. We investigated a modified patient position to increase stone-free rate by analyzing presence of residual fragments. We randomized patients into standard position and the T-Tilt position (15° Trendelenburg and 15° airplane away from the surgical side kidney). MATERIALS AND METHODS: In this prospective, randomized study, patients were randomized into the standard or T-Tilt position. Demographics, comorbidities and operative parameters were collected. Stone-free rate was determined with renal ultrasound and x-ray at 1-month followup. Postoperative complications were recorded up to 1 month. Variables were compared using Kruskal-Wallis test for continuous variables and chi-square test for categorical variables. RESULTS: A total of 138 patients were analyzed: 75 standard patients and 63 T-Tilt patients. The groups had similar patient and stone factors. The most common stone position was the lower pole (68.0% standard, 74.6% T-Tilt). Stone-free rates were significantly different: standard position was 76.7% and T-Tilt position was 92.1% (p=0.015). Stone-free rates for isolated lower pole stones were significantly different as well: standard position was 68.2% and T-Tilt position was 95.6% (p <0.001). Clavien-Dindo scores did not differ significantly (p=0.262). CONCLUSIONS: The T-Tilt patient position was associated with higher stone-free rates. It is an atraumatic, cost-effective technique. These results suggest that modifying patient positioning during retrograde intrarenal surgery improves stone-free rates.

A randomized clinical trial evaluating the short-term results of ureteral stent encrustation in urolithiasis patients undergoing ureteroscopy: micro-computed tomography evaluation.

Although many ureteral stents are commercially available, the actuality of encrustation is yet to be elucidated in humans. This study compared the Tria Ureteral Stent with PercuShield and the Polaris Ultra Ureteral Stent with HydroPlus Coating for short-term encrustation formation. Eighty-four patients, who required ureteral stent placement after ureteroscopy, were randomized into two stent groups. After stent removal on postoperative day 14, the encrustation volume on the stent surface was measured by micro-computed tomography. The primary outcome was the inner luminal encrustation volume. Secondary outcomes were encrustation volume on the outer or total surfaces and occurrence of adverse events. Clinical factors related to encrustation were also assessed as a post-hoc analysis. Finally, of the 82 patients analyzed, 75 (91.5%) had encrustation in the inner lumen of the stent. The difference in median inner encrustation volume between the Tria and Polaris Ultra stents was comparable (0.56 vs. 0.37 mm3, P = 0.183). There was no difference observed in the encrustation volume on the outer/total surfaces and stent-related adverse events. In both ureteral stents, the shaft body showed significant inner luminal encrustation compared to the proximal or distal loop (all, P < 0.05). Dyslipidemia (P = 0.027), elevated urine pH (P = 0.046), and crystalluria (P = 0.010) were associated with encrustation formation. The Tria and Polaris Ultra stents had similar efficacy for preventing encrustation in the short-term. Further studies are required to compare their long-term patency.

Flexible fibre optic vs digital ureteroscopy and enhanced vs unenhanced imaging for diagnosis and treatment of upper tract urothelial carcinoma (UTUC): results from the Clinical Research Office of the Endourology Society (CROES)-UTUC registry.

OBJECTIVES: To compare the oncological outcomes of patients with upper tract urothelial carcinoma (UTUC) undergoing kidney-sparing surgery (KSS) with fibre-optic (FO) vs digital (D) ureteroscopy (URS). To evaluate the oncological impact of image-enhancement technologies such as narrow-band imaging (NBI) and Image1-S in patients with UTUC. PATIENTS AND METHODS: The Clinical Research Office of the Endourology Society (CROES)-UTUC registry is an international, multicentre, cohort study prospectively collecting data on patients with UTUC. Patients undergoing flexible FO- or D-URS for diagnostic or diagnostic and treatment purposes were included. Differences between groups in terms of overall survival (OS) and disease-free survival (DFS) were evaluated. RESULTS: The CROES registry included 2380 patients from 101 centres and 37 countries, of whom 401 patients underwent URS (FO-URS 186 and D-URS 215). FO-URS were performed more frequently for diagnostic purposes, while D-URS was peformed when a combined diagnostic and treatment strategy was planned. Intra- and postoperative complications did not differ between the groups. The 5-year OS and DFS rates were 91.5% and 66.4%, respectively. The mean OS was 42 months for patients receiving FO-URS and 39 months for those undergoing D-URS (P = 0.9); the mean DFS was 28 months in the FO-URS group and 21 months in the D-URS group (P < 0.001). In patients who received URS with treatment purposes, there were no differences in OS (P = 0.9) and DFS (P = 0.7). NBI and Image1-S technologies did not improve OS or DFS over D-URS. CONCLUSIONS: D-URS did not provide any oncological advantage over FO-URS. Similarly, no differences in terms of OS and DFS were found when image-enhancement technologies were compared to D-URS. These findings underline the importance of surgeon skills and experience, and reinforce the need for the centralisation of UTUC care.

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.

The Innovative Use of Ureter Catheter in the Surgery of Obstructive Uropathy.

PURPOSE: Relieving obstruction and protecting renal function are the main therapeutic purposes of obstructive uropathy which often involve surgical treatment, and the ureter catheter is one of the surgical instruments commonly used in surgery. We aimed to explore the innovative use of a ureter catheter in the surgery of obstructive uropathy. METHODS: We used a ureteral catheter to innovate the surgical procedure of the most common causes of obstructive uropathy: ureteral calculi and stricture, establishing an internal circulation system (ICS), proposing a three-step dilatation method, and reviewing their effects on patients. Furthermore, we introduced a simple real-time intrapelvic pressure measurement device to monitor intrarenal pressure during operation. RESULTS: Postoperative laboratory examination showed that blood CRP, leukocyte neutrophil level, changes in the hemoglobin, urine occult blood, and positive rate of urine culture in the ICS group are significantly lower than those in the control group, corresponding to a lower incidence of bleeding and infection-related complications clinically. A three-month follow-up revealed 1/3 rate of ureteral stricture in the ICS group comparing to the control. We applied the three-step dilatation in patients with severe stenosis in which the balloon could not pass; the overall effective rate was 90.9%. The pressure of the renal pelvis was displayed on the monitor in real time. The surgeon could estimate the degree of filling of the renal pelvis and adjust the intake volume through the data. CONCLUSION: The innovative application of ureteral catheters in the operation of obstructive uropathy can realize the real-time monitor of intraoperative renal pelvis pressure, reduce the incidence of lithotripsy postoperative complications, and expand the indications of balloon dilatation in ureteral stricture, which has certain clinical significance.

Rigid and flexible ureteroscopy (URS/RIRS) management of paediatric urolithiasis in a not endemic country.

INTRODUCTION: In the last years due to miniaturization of endoscopic instruments and percutaneous surgery, endourology has become very popular in paediatric urinary stone managment. We reported our single-centre experience in retrograde endoscopic procedures in children. Results and complications of URS/RIRS are discussed. MATERIALS AND METHODS: We retrospectively reviewed our experience in patients ≤ 16 years old affected by urinary stones who underwent URS/RIRS procedures performed by two surgeons with expertise in endourology. A total of 30 renal Units (RUs) underwent endoscopic procedures (URS, RIRS or both). Surgical complications according to the ClavienDindo's classification and stone-free rate were evaluated at 3 months follow-up. Success of URS was defined as stone-free status after single procedure while RIRS success rate was considered as presence of residual stone fragments smaller than 4 mm at first procedure. RESULTS: The mean age of our patients was 8 years, range 2- 16 years. A total of 30 renal units (RUs) underwent 40 endourological procedures (23 URS and 17 RIRS; 10 children underwent both procedures at the same time). 17/30 (56.6%) RUs were pre-stented before surgery. The stone-free status was achieved in 23/30 renal units treated, with a 76.6% success rate. The remaining 7 patients had residual stones greater than 4 mm and underwent further treatments. After a second surgery the stone-free rate turned out to be 93.3% (28/30 renal units). CONCLUSIONS: Rigid and flexible ureteroscopy (URS/RIRS) is a reliable technique for treatment of < 2 cm urinary stones in paediatric age group. It shows low rate of major complications and promising results in terms of stone-free rate.

The feasibility of one-stage flexible ureteroscopy lithotripsy in solitary kidney patients with 1-3 cm renal stones and risk factors of renal function changes.

PURPOSE: To compare perioperative outcomes and long-term renal function changes between prior stenting (PS) and not prior stenting (NPS) before flexible ureteroscopy lithotripsy (f-URS) for solitary kidney patients. METHODS: Solitary kidney patients with 10-30 mm renal stones were enrolled in this historical control study. Perioperative parameters and complications were compared. Stone-free was defined as the absence of any residual stones on a CT scan. Renal function changes were evaluated by estimated glomerular filtration rate (eGFR) and adjusted for body surface area. A decrease in the eGFR over 20% was identified as 'deterioration' in renal function. The follow-up period was at least 6 months. Logistic regression was used to identify risk factors of renal function deterioration. RESULTS: Of the 76 patients included, 40 cases experienced prior stenting before f-URS. The average stone diameter was 16.8 ± 4.7 mm, ranging from 10.0 to 28.4 mm. Initial SFR was 85.0 and 83.3% in the PS and NPS groups, respectively (p = 0.842), while SFR after the second procedure was 97.5 and 94.4% (p = 0.926). Seven PS and 5 NPS patients developed complications (p = 0.666). At the postoperative 6 months, seven patients showed a deteriorated renal function. Surgical time in minutes was identified as a risk factor for renal function deterioration after the operation (OR = 1.061, 95% CI: 1.015-1.109, p = 0.009, per minute). CONCLUSION: It appears that one-stage f-URS without PS could be feasible for 10-30 mm renal stones in solitary kidney patients, and less surgical time might be beneficial to protect renal function.

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.

Does the renal parenchymal thickness affect the efficacy of the retrograde intrarenal surgery? A prospective cohort study.

Retrograde intrarenal surgery (RIRS) is one of the minimally invasive main treatment modalities in renal stone disease. There are many factors which affect stone-free rate (SFR). Our study was based on the hypothesis that higher renal parenchymal thickness (RPT) which may include higher average number of nephrons provides better diuresis. We investigated the efficacy of RPT on success of RIRS. This study is a single-centered prospective surgical cohort study. A total of 383 patients were analyzed. Regularly followed 304 patients with unilateral kidney stone at single pole or renal pelvis and who underwent single-session RIRS were included in the final analysis, and the patients' preoperative and postoperative 1st and 3rd months' data were evaluated. RPT was measured on the non-contrast computed tomography (CT) images. ROC analysis was performed to estimate the cutoff value of RPT for SFR. Univariate and multivariate logistic regression analyses were used to model the relationship between RPT and SFR after RIRS. ROC analysis revealed the best cutoff value of the RPT for predicting residual stone as 19 mm for both the 1st and 3rd month visits with Youden indexes of 0.397 and 0.406, respectively. To the best of our knowledge, this is the first study which evaluated the effect of RPT on the efficacy of RIRS. RPT measurement is a cost-effective method that can be easily performed on routinely applied non-contrast CT and may have predictive value for the surgical success in patients with nephrolithiasis.

Gap between UAS and ureteroscope predicts renal stone-free rate after flexible ureteroscopy with the fragmentation technique.

PURPOSE: To assess the effect of our new classification on surgical outcomes after flexible ureteroscopy (fURS) for kidney stones. METHODS: We retrospectively examined 128 patients after single renal fURS procedures performed using ureteral access sheaths (UASs) with the fragmentation technique. Based on the gap (calculated by subtracting the ureteroscope diameter from the UAS diameter), enrolled patients were divided into three groups: small (< 0.6 mm), medium (0.6 to < 1.2 mm), and large space groups (≥ 1.2 mm). Stone-free (SF) status was defined as either complete absence of stones (SF) or the presence of stones < 4 mm in diameter on non-contrast computed tomography (NCCT). RESULTS: The SF rate was significantly lower in the small space group (50% in small, 97.9% in medium, 89.2% in large; p = 0.001). Perioperative complications over Clavien-Dindo Grade I were observed in 16.7%, 4.2%, and 8.1% of patients, respectively (p = 0.452). The ratio of stone volume and operative time (efficiency of stone removal) was significantly higher in the large space group compared to the small and medium space groups (0.009 ± 0.003 ml/min, 0.013 ± 0.005 ml/min, 0.027 ± 0.012 ml/min, respectively; p < 0.001). CONCLUSION: Our findings that gaps > 0.6 mm (1.8 Fr), including the combination of a 9.5-Fr UAS and a small caliber ureteroscope, improve SF rates, and larger gaps facilitate stone removal efficiency providing the basis for future development of clinical protocols aimed at improving outcomes.

In-vitro and in-vivo new evidence for Flexor® Vue™ deflecting endoscopic system use: optimization of the stone free rate (SFR) after flexible ureteroscopy and Ho:YAG laser lithotripsy.

To test in-vitro and in-vivo the Flexor® Vue™ deflecting endoscopic system (FVDES) as a new technology able to improve the removal of residual intrarenal fragments.This is an observational prospective "proof of concept" study performed in patients with renal calculi treated with flexible ureteroscopy and Ho:YAG laser lithotripsy (f-URS) in Humanitas Research Hospital (Rozzano, Italy). We assessed feasibility, efficacy and safety of FVDES as an in-vivo tool for removing residual fragments after f-URS. The stone-free rate (SFR) at 30 days post-operatively was evaluated using CT. An in-vitro model was developed to evaluate the FVDES when used for this purpose.Eleven patients (M/F ratio: 7/4, mean age 63.5 ± 8.3) were treated. The stones were located in the lower calyces and the renal pelvis in 3 and 8 patients, respectively. Mean stone size was 18 ± 3.2 mm. The procedure with FVDES was feasible and effective in all the patients. Mean operative time was 82 ± 13.7 min and median hospitalization was of 1.5 days. The SFR after 90 days was 81% (9/11). We reported no relevant complications (Clavien-Dindo > 2); one patient had fever and was treated with antibiotics. The experimental in-vitro model demonstrated the efficacy of FVDES, allowing the removal of about 90% of fragments.Our study showed that FVDES is effective when used as a tool for retrieval of residual fragments at the end of f-URS. This technology could ensure a complete cleaning of the intrarenal collecting system and represent a safe alternative to basketing.