Ureteroscopic lithotripsy in Trendelenburg position for proximal ureteral calculi: a prospective, randomized, comparative study

The reverse Trendelenburg position in proximal ureteral stone management: A systematic review and meta-analysis

INTRODUCTION

Ureteroscopy lithotripsy (URSL) presents a therapeutic option for patients with proximal ureteral calculi warranting active removal. This systematic review and meta-analysis aimed to assess the efficacy of the reverse Trendelenburg (RT) position during this procedure.

MATERIALS

A comprehensive literature search was conducted across PubMed, Embase, and Cochrane databases to identify randomized controlled trials and observational studies comparing RT versus standard positioning (STD) in patients undergoing URSL for proximal ureteral stones. Heterogeneity was measured with the Cochran's Q test, I2 statistics, and prediction intervals (PI). A DerSimonian and Laird random-effects model was utilized for all outcomes.

RESULTS

Four studies encompassing 505 patients undergoing URSL were analyzed. Among the studied participants, 293 (58%) underwent RT positioning. Overall, RT was associated with a lower average incidence of stone retropulsion (RR 0.42; 95% CI 0.27-0.65; I2=48%; PI 0.08-2.10) and a higher mean stone-free rate (RR 1.33; 95% CI 1.18-1.49; I2=0%). However, no significant difference between groups was found in the mean rate of overall complications (RR 0.76; 95% CI 0.40-1.43; I2=51%; PI 0.00-520.22) and operative time (MD -0.65; 95% CI -9.58-8.27; I2=94%; PI -111.95-110.65). In those with proximal ureteral stones undergoing RT positioning at only the 20° angle, there was a reduction in stone retropulsion without any measured heterogeneity (RR 0.35; 95% CI 0.23-0.52; I2=0%).

CONCLUSION

These findings suggest that RT positioning is effective in improving outcomes for patients with proximal ureteral stones undergoing URSL, and its use should be considered during the procedure.

The relationship between stone-free and patient position in retrograde intrarenal surgery: a randomized prospective study

PURPOSE

Residual fragments not removed with urinary stone surgery may become symptomatic. In this context, this study was carried out to investigate the effect of performing retrograde intrarenal surgery, which is conventionally performed in the lithotomy position, in the modified lithotomy position (Trend-side) on stone-free rates following the surgery.

METHODS

This prospective study consisted of 100 patients with a single kidney stone smaller than 2 cm between 2021 and 2023. These patients were randomized into two groups of 50 patients each to be operated on in the conventional lithotomy and Trend-side positions. Variables were compared using independent t test for continuous variables and chi-square test for categorical variables.

RESULTS

There was no significant difference between the lithotomy and Trend-side position groups in terms of preoperative size, density, location of the stone, and hydronephrosis degree. Stone-free rate was 72% (n = 36) in the lithotomy group and 92% (n = 46) in the Trend-side group. Hence, there was a significant difference between the groups in the stone-free rate in favor of the Trend-side group (p = 0.009). Fragmentation time was statistically significantly shorter in the Trend-side group than in the lithotomy group (34 ± 17 min vs. 43 ± 14 min; p = 0.006). There was no significant difference between the groups in postoperative complication rates.

CONCLUSION

Performing retrograde intrarenal surgery in the Trend-side position shortened the duration of fragmentation compared to the lithotomy position and was associated with higher stone-free rates. In conclusion, the Trend-side position can be safely preferred in patients undergoing retrograde intrarenal surgery due to kidney stones.

A new position utilizing the effect of gravity in proximal ureteral stones, ureteroscopic lithotripsy in the reverse Trendelenburg position: a prospective, randomized, comparative study

PURPOSE

To evaluate the effect of the reverse Trendelenburg position in patients undergoing ureteroscopic lithotripsy for proximal ureteral stones.

METHODS

The study included 167 patients who underwent ureteroscopic lithotripsy for proximal ureter stones between December 2020 and September 2022. The patients were randomly assigned to one of three groups: standard lithotomy (n:55), 10° reverse Trendelenburg (n:55), and 20° reverse Trendelenburg (n:57). Preoperative information, including age, sex, body mass index (BMI), previous shock wave lithotripsy (SWL), stone side, volume, and density, distance to the ureteropelvic junction (UPJ) of the stone, and hydronephrosis degree. Stone-free status was evaluated with computed tomography (CT) at 4 weeks postoperatively. The groups were compared in respect of stone migration, stone-free rate, use of flexible ureterorenoscope, operating time, postoperative length of stay in the hospital, and complications.

RESULTS

No statistically significant difference was determined between the groups with respect to age, sex, BMI, previous SWL, stone side, volume and density, distance to the UPJ of the stone, and hydronephrosis degree (p > 0.05 for all). Statistically significant differences were determined between the groups with respect to stone migration (p = 0.001), stone-free rate (p < 0.001), use of flexible ureterorenoscope (p = 0.01), operating time (p < 0.001), hospital length of stay (p < 0.001), postoperative fever (p = 0.002), and total complications (p = 0.01).

CONCLUSION

A new patient position is presented in this study, which can be used in ureteroscopic lithotripsy performed for proximal ureteral stones. The reverse Trendelenburg position constitutes a surgical method that can be used safely and successfully in the treatment of proximal ureteral stones.

TRIAL REGISTRATION NUMBER

NCT04894058, 05/21/2021, Prospectively registered.

Ureteral inflammatory edema grading clinical application

Purpose

To evaluate the relationship between endoscopic ureteral inflammatory edema (UIE) and ureteral lumen, formulate a preliminary grading method for the severity of UIE, and analyze the impact of different grades of UIE on endoscopic ureteral calculi surgery and prognosis.

Materials and methods

We retrospectively analyzed 185 patients who underwent ureteroscopic lithotripsy (URSL) for upper urinary tract stones between January 2021 and November 2021. The UIE grade and lumen conditions were assessed by endoscopic observation. The effect of UIE grade on URSL and on patient prognosis were analyzed by multiple linear regression and binary logistic regression.

Results

A total of 185 patients were included in the study. UIE grade showed a significant correlation with age, hydronephrosis grading (HG), ureteroscope placement time (UPT), surgery time (ST), hemoglobin disparity value (HDV), and postoperative ureteral stenosis (PUS) (P < 0.05). Logistics regression analysis showed a gradual increase in intraoperative UPT and ST with increase in UIE grade. The severity of UIE showed a negative correlation with improvement of postoperative hydronephrosis (IPH) and the appearance of PUS. HDV was significantly increased in patients with UIE grade 3.

Conclusions

UIE grading can be used as an adjunctive clinical guide for endoscopic treatment of upper urinary tract stones. The postoperative management measures proposed in this study can help inform treatment strategy for ureteral stones.

Reverse Trendelenburg Lithotomy with Certain Inclination Angles Reduces Stone Retropulsion during Ureteroscopic Lithotripsy for Proximal Ureteral Stone

The objective of this study is to investigate how different inclination angles of reverse Trendelenburg lithotomy affect stone retropulsion and stone-free rates during ureteroscopic lithotripsy for proximal ureteral stones. Patients with proximal ureteral stones undergoing ureteroscopic lithotripsy in our institution between January 2019 and December 2020 were included according to predefined criteria. The rigid ureteroscope and Holmium: YAG laser were utilized to perform lithotripsy, and a stone basket was used to keep the stone in place and to avoid retropulsion. Before initiating lithotripsy, the upper part of the patient’s body was tilted up to establish a reverse Trendelenburg posture with appropriate inclination angles. To quantify the stone-free rate, computed tomography was used to evaluate the residual stones in the kidney one month following surgery. Patients’ clinical data were obtained retrospectively, including age, gender, the largest diameter of stone, stone density on computed tomography, and the distance between stone and ureteral pelvic junction, etc. Patients were divided into four groups based on the inclination angles of reverse Trendelenburg lithotomy: 0°, 10°, 20°, and 30°. The chi-square test was used to compare stone retropulsion and stone-free rates between groups. To discover possible determinants of the stone-free rate, logistic regression analyses were used. There were 189 patients that qualified. There were no differences in clinical characteristics between groups (p > 0.05). Multiple comparisons between groups revealed that the 20° and 30° groups had less retropulsion and a greater stone-free rate than the 0° and 10° groups (p < 0.05), whereas there were no significant differences in stone retropulsion or stone-free rates between the 20° and 30° groups or between the 0° and 10° groups (p > 0.05). The inclination angles as well as distance between the stone and ureteral pelvic junction were identified by using logistic regression analyses as the related factors for the stone-free rate. According to our results, the appropriate inclination angles of reverse Trendelenburg lithotomy during ureteroscopic lithotripsy for proximal ureteral stones would help preclude stone retropulsion and increase the stone-free rate.

The effect of Trendelenburg position on outcomes of retrograde intrarenal surgery for medium sized renal pelvis stones

Aim: To compare safety and efficiency between Trendelenburg position retrograde intrarenal surgery (tRIRS) and conventional position retrograde intrarenal surgery (cRIRS) in the management of renal pelvis stones 10-20 mm in size. Material and Method: From September 2018 to September 2019, the patients undergoing RIRS for single renal stones between 10-20 mm were included in the study prospectively. Patients were divided into two groups randomly. First group of patients were positioned completely parallel to the ground (cRIRS), second group were positioned with Trendelenburg (tRIRS). Success was evaluated at end of 3rd months by non-contrast enhanced tomography. Stones that smaller than 4 mm were accepted as clinical insignificant residual fragment. Complications was classified according to Clavien, class 2 or more complications were recorded. Results: Totally 100 patients were included to final analyze. Patients’ age, gender, stone side and mean stone surface area were similar between groups. Success rate was higher in tRIRS group (90% vs 72% p=0.022). Mean operation time was lower (41.8 vs 58.2 min. p

The use of 14/16Fr ureter access sheath for safe and effective management of large upper ureteral calculi

OBJECTIVE

To evaluate the effectiveness of ureteroscopic lithotripsy for the management of large proximal ureteral stones > 10 mm using 14/16 Fr ureteral access sheath (UAS).

MATERIALS AND METHODS

Patients' data from prospective database undergoing ureteroscopic laser lithotripsy with a use of 14/16Fr UAS were collected. All patients were pre-stented prior to the procedure. The fragmentation was performed with a semi-rigid ureteroscope using holmium laser energy with a power setting of 35 W (frequency-35 Hz; energy-1 J). Follow-up was scheduled at 4 weeks and 3 months postoperatively.

RESULTS

In total 78 patients, 43 males and 35 females, were included in the study. The mean age of the patients was 59.5 ± 13.3 with a mean maximal stone diameter of 13.4 ± 2.1. The mean operative time was 35.7 ± 9.7 and the mean hospital stay was 2 ± 0.7 days. The primary SFR at 4 weeks was 73 patients (93.6%), while all 78 patients (100%) were stone free at 3-month follow-up, 2 of the patients receiving additional treatment. In total, 8 (10.2%) patients experienced Grade II complications. Intraoperative ureteral lesions were observed in 41 (52.6%) cases. Out of them 31 patients (39.7%) developed Grade 1, 8 patients (10.3%) Grade 2 and only 3 patients (2.6%) Grade 3 lesions.

CONCLUSION

The use of 14/16Fr ureteral access sheath on pre-stented patients was associated with successful outcomes. A high stone-free rate of 93.6% was achieved at 4-week follow-up. The procedure was not associated with increased rate of postoperative complications and intraoperative ureteral injury.

Is there any predictive value of the ratio of the upper to the lower diameter of the ureter for ureteral stone impaction?

Background:

We aimed to determine if the ratio of the upper to the lower diameter of the ureter could have any predictive value for ureteral stone impaction.

Materials and methods:

Patients who had a solitary unilateral ureteric stone, determined by noncontrast computerized tomography, were assessed if they had undergone ureteroscopic lithotripsy. A total of 111 patients, 84 males (76%), and 27 females (24%), were recruited to the study. Demographic data of the patients and preoperative radiological parameters based on noncontrast computerized tomography were recorded. The impaction status was also assessed during the operation.

Results:

Of the 111 patients, ureteral stones in 63 (57%) patients were determined to be impacted, and ureteral stones in 48 (43%) were nonimpacted. Impacted stones were more common in older patients, female patients, and patients with an American Society of Anesthesiologists score of 2.

Conclusions:

Significant relationships were found between the impaction status and transverse stone length, longest stone length, upper diameter of the ureter, ratio (upper diameter of the ureter/lower diameter of the ureter), and anteroposterior diameter of the pelvis. These parameters were higher in patients with impacted stones.

'Boxing in the corner': A modified retrograde approach for the management of proximal ureteric stones of 1-2 cm

Objectives: To study a modification to the conventional retrograde ureteroscopic approach for treating proximal ureteric stones of 1–2 cm; we intentionally push the stone from the proximal ureter into a favourable calyx then the flexible ureteroscope is used to fragment the trapped stone using laser lithotripsy (‘boxing in the corner’).

Patients and methods: The study was conducted in a randomised prospective manner and included 100 patients who presented with a single proximal ureteric stone of 1–2 cm. We randomised the patients into two equal groups: Group A (50 patients) underwent the conventional retrograde technique (CRT) and Group B (50 patients) underwent the modified retrograde technique (MRT) with the primary intention of relocating the stone into a favourable calyx. Intended relocation of the proximal ureteric stone in the MRT group was achieved in a stepwise manner. All intraoperative parameters and postoperative outcomes were recorded and compared between the two groups.

Results: There was no statistical significant difference in terms of the patients’ demographics and stone criteria between the two groups. The stone-free rate (SFR) was significantly higher in Group B (92%) compared to Group A (78%) (P = 0.049). Fluoroscopy time was significantly longer in Group B (P < 0.001), while operative time, lithotripsy time and hospital stay were comparable. There was no difference between the groups regarding complications.

Conclusion: The MRT was found to be safe and more effective than the CRT for treating proximal ureteric stones of 1–2 cm, with a significantly higher SFR.

Abbreviations CONSORT: Consolidated Standards of Reporting Trials; ESWL: extracorporeal shockwave lithotripsy; fURS: flexible ureteroscope; NCCT: non-contrast CT; SFR: stone-free rate; YAG: yttrium-aluminium-garnet

Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy

Purpose

To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety.

Methods

A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark.

Results and conclusions

Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.

Updates in endourological management of urolithiasis

Urinary stone disease, or urolithiasis, is a very common disease with increasing prevalence and incidence. With the advancement of endoscopic techniques, the treatment outcomes of ureteroscopy (or transureteral lithotripsy) and percutaneous nephrolithotomy are continuously improving. In recent years, there have been many new developments in the field, including new endoscopy design, more effective auxiliary tools, improvement in treatment protocols, introduction of robotic technology, combining both ureteroscopy and percutaneous nephrolithotomy (endoscopic combined intrarenal surgery or transureteral lithotripsy-assisted percutaneous nephrolithotomy), improvement in laser technology, and so on. All these new inputs will further improve the treatment efficacy and safety of the procedures, thus benefiting our patients. In the present review, we briefly go through the main steps of ureteroscopy and percutaneous nephrolithotomy, with a concise description and application of these new advances.

The application of a single-use fiberoptic flexible ureteroscope for the management of upper urinary calculi

OBJECTIVE

To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database.

MATERIALS AND METHODS

A prospective study was conducted in a single center in China between January 2016 and October 2017. All consecutive patients who underwent flexible ureteroscopy performed by YouCare flexible ureteroscope were analyzed. Patients' demographics, clinical characteristics, intraoperative parameters, postoperative complications, and stone-free rate were evaluated and recorded. Stone-free status was defined as no visible stones or clinically insignificant residual stones < 2 mm on a postoperative image study.

RESULTS

A total of 684 procedures were performed for 653 patients (31 patients had bilateral stones). A double J stent had been previously placed in 431 patients. The location of the calculi was upper calyx, middle calyx, lower calyx, and renal pelvis and proximal ureter in 74, 101, 211, 115, and 183 patients, respectively. The median operative time was 52 min. The postoperative stone-free rate for the first 2 weeks after surgery was 78.5%, which increased to 91.1% at the first month. The overall stone-free rate was 95.2%. The complication rate was minor and short-term, such as gross hematuria or flank pain.

CONCLUSION

YouCare flexible ureteroscope can be considered effective and safe in the treatment of both upper ureteral and renal stones in selected patients. Further evaluation of comparison with other FURS's surgical outcomes and cost-effectiveness analysis will help to present the best utility of this single-use FURS in clinical practice.

Comparison of ureteroscopic laser lithotripsy with laparoscopic ureterolithotomy for large proximal and mid-ureter stones

OBJECTIVES

To compare the effectiveness and complications of ureteroscopic laser lithotripsy with laparoscopic ureter laparoscopic ureterolithotomy in mid- or proximal portion of large ureteral stones.

MATERIAL AND METHODS

We reviewed patients with large (>15 mm) ureteral stone and those who underwent ureteroscopic laser lithotripsy (URS group) or laparoscopic ureterolithotomy (LU group). The first attempt was considered successful in patients who had residual fragments smaller than 2 mm and no conversion of the primary procedure to another.

RESULTS

Sixty patients (URS group 29, LU group 31) met inclusion criteria. FURS was used as an adjunctive procedure in one patient for URS group and in two patients for LU group in the same season. LU had a higher success rate and the first-day stone-free rate when compared with URS. Number of procedures was also significantly higher in URS group. There was no difference in stone-free rates at the first and third months, and length of hospitalization and operation were higher in the LU group. Only two patients in the LU group and one patient in the URS group had major complications.

CONCLUSIONS

Laparoscopy is an effective option of large proximal and mid-ureter stone treatment; however, URS provides similar stone-free rates at three months as a minimal invasive procedure.