Abstract
Purpose
Comparative effectiveness of suction versus traditional ureteral access sheath (UAS) remains an area of ongoing research. We aim to compare the outcomes of retrograde intrarenal surgery (RIRS) with suction and standard UAS versus without UAS in the management of renal and upper ureteric stones, with a specific focus on operative efficiency, stone-free rates, and postoperative complications.
Methods
This study was conducted between October 2023 and January 2025, including 90 patients with renal stones ≤ 3 cm and upper ureteric stones ≤ 1.5 cm. Patients were divided into three groups by random Allocation Software (version 2): Group A1 (standard UAS, n = 30), Group A2 (suction UAS, n = 30), and Group B (no UAS, n = 30). Operative time, vision quality, stone clearance, complications, and hospital stay were assessed.
Results
Group A2 had the shortest mean operative time (70.1 ± 10.3 min) with significantly better vision compared to Group A1 (114.3 ± 27.0 min) and Group B (125.0 ± 28.01 min) (p < 0.001). Residual stone rates were lowest in Group A2 (3.3%) compared to Group A1 (10.0%) and Group B (26.7%) (p = 0.035). The need for a second procedure was significantly higher in Group B (26.7%) compared to Group A1 (10.0%) and absent in Group A2 (p = 0.002). Hospital stay was significantly shorter in Group A2 compared to Group A1 and Group B (p = 0.005). Fever incidence (Clavien Grade II) was significantly higher in Group B (23.3%) compared to Group A1 (16.7%) and absent in Group A2 (p = 0.005).
Conclusion
Suction ureteral access sheaths in flexible ureteroscopic lithotripsy for renal stones ≤ 3 cm and upper ureteric stones ≤ 1.5 cm was associated with improved stone clearance, reduced operative time and hospital stay, provide better endoscopic vision, minimized infectious complications and need for second procedure, compared to standard UAS or no sheath. However, outcomes may be influenced by surgeon experience and familiarity with suction-assisted systems. Prospective multicenter studies with larger sample sizes and varying surgeon experience levels are recommended.
Keywords: Flexible Ureteroscopy, Suction ureteral access sheath, Kidney stones, Sheathless
Introduction
Renal and upper ureteric stones is a growing health concern, with its prevalence rising up to 10.1%, and lifetime risk estimates reaching approximately 13% in men and 7% in women [1]. Flexible ureteroscopy (fURS) has become a widely used minimally invasive approach for the management of renal and upper ureteric stones. This procedure utilizes flexible ureteroscopy to access and treat stones within the kidney and upper ureter, offering a less invasive alternative to percutaneous nephrolithotomy and shock wave lithotripsy [2].
To enhance the efficiency of retrograde intrarenal surgery (RIRS), the use of ureteral access sheath (UAS) has been earning popularity in recent years. UAS facilitates access to the kidney by providing a stable working channel for flexible ureteroscopes. This device allows for repeated instrument exchanges, improves visualization, and reduces intrarenal pressure during the procedure, thereby enhancing surgical outcomes [3, 4]. Additionally, the UAS enables better irrigation control, minimizes irrigation fluid leakage, and may contribute to higher stone-free rates (SFR) [5].
Despite its advantages, the use of UAS remains a topic of debate due to potential complications. While some studies have reported improved operative efficiency, shorter procedural times, and reduced postoperative infectious complications with UAS, concerns persist regarding ureteral trauma, including mucosal injury, stricture formation, and bleeding [6, 7]. Furthermore, variations in UAS design—such as caliber, flexibility, and suctioning mechanisms—may influence its safety and efficacy, necessitating careful selection based on patient-specific factors [8].
Recent advancements in UAS technology, including suction-assisted models, have aimed to mitigate these risks while optimizing procedural outcomes. Suctioning UAS, which integrates an aspiration system to remove stone fragments and reduce intrarenal pressure, has demonstrated potential benefits in improving SFR and reducing infectious complications [9–11]. However, the comparative effectiveness of suction versus traditional UAS remains an area of ongoing research. Our study aims to compare the outcomes of RIRS with suction and standard UAS versus without UAS in the management of upper ureteric and renal stones, with a specific focus on operative efficiency, stone-free rates, and postoperative complications.
Methods
The study was conducted prospectively in our Urology Department between October 2023, and January 2025. Written informed consent was gained from all recruited patients.
The study included patients with renal calculi up to 3 cm and upper ureteric stones up to 1.5 cm. Patients were randomized using Random Allocation Software (version 2) creating a sequence by simple randomization dividing them into three groups. Allocation concealment was performed by using sealed opaque envelopes, which were opened only after patient enrollment. The randomization was performed by an independent investigator not involved in the endoscopic procedures or postoperative assessments to ensure allocation concealment. Group A underwent fURS with UAS, while Group B underwent fURS without UAS. Group A was further subdivided into Group A1, where a standard UAS was used (12/14 Fr, 45 cm, Coloplast), and Group A2, where a flexible suction sheath (10/12 Fr/46 cm, Clear Petra) was utilized. Digital FURS (LithoVue - Boston Scientific) with 7.7 Fr tip diameter was used. Exclusion criteria included renal stones > 3 cm, upper ureteric stones > 1.5 cm, lower ureteric stones, pre-stented ureter, active urinary tract infections (UTIs), patients administrated alpha blockers for pharmacological ureteral relaxation and patients who declined randomization.
All patients underwent a detailed medical history and physical examination, abdominopelvic ultrasound, non-contrast computed tomography, urine analysis, and culture. In positive preoperative urine culture, patients receive proper antibiotic therapy.
A single intravenous dose of a cephalosporin antibiotic was administered pre-general anesthesia. All procedures were completed by a single expert surgeon to standardize the technique. A cystoscope (25 Fr, Karl Storz) was introduced to identify the ureteric orifice, and a 0.035-inch Sensor guidewire was introduced with the patient in the lithotomy position. Another guidewire (safety wire) was introduced through the cystoscope, followed by diagnostic 7.5 tip semi-rigid ureteroscopy to estimate the ureter. The standard UAS was then inserted under safety guidewire guidance. The fURS was introduced and advanced towards the stone. In patients with tight ureter not accommodating the UAS or fURS, the ureter is stented, and fURS is deferred for two to four weeks.
Lithotripsy was accomplished using a Holmium YAG laser 30 Watts (Sphinx, LISA Laser, Katlenburg-Lindau, Germany) within a 200-µm fiber. The high energy (1–1.2 J/8–10 Hz) was for stone fragmentation and low energy (≤ 0.5 J/15–25 Hz) for dusting. Irrigation inflow pressure generated by placing irrigation fluid 40–80 cm above the patient with and without manual hand pumps for better visualization. In FURS with suction UAS, the UAS was linked to a vacuum device, with negative suction pressure maintained between 20 kPa to 40 kPa, to balance debris evacuation and visualization. During the procedure, the surgeon continuously moved the sheath in and out to facilitate stone fragment evacuation through irrigation. In fURS without UAS, the flexible ureteroscope was introduced directly into the ureter without the use of a UAS. A DJ stent (5/6–26 Fr) was inserted in all our included patients and removed 21 days postoperatively.
Patient-related data, including full medical and surgical history, age, gender, body mass index (BMI) and stone-related data, including stone site, size, volume, number and density were collected. Intraoperative data, including operative time, fluoroscopy time, vision changes (5-points Likert score with grading from 1 to 5 coinciding to very poor to very good) and ureteral injury were recorded. Low-grade ureteral trauma was injury of ureteral mucosa not reaching smooth muscle and high-grade trauma was injury expanding to ureteral smooth muscle. This was according to Traxer and Thomas, 2013 grading system [12]. Postoperative assessments included complications (fever and hematuria), hospital stay duration, burden of residual stone, and the need for a second procedure if necessary. SFR was assessed by spiral CT scan after 6 weeks using the same institutional CT protocol to ensure uniform assessment. Stone free status was performed by independent radiologists who were blinded to group allocation and was defined by insignificant residual stones ≤ 4 mm or no residual stone. This threshold is commonly used to represent clinically insignificant residual fragments with less likely to require further intervention [13].
Sample size justification was based on differences in operative time reported in comparable studies. Based on pooled data, the estimated effect size (Cohen’s f) was approximately 0.29, which reflects a medium-to-large effect size. According to standard power analysis (α = 0.05, power = 80%), a minimum of 28 patients per group would be required to detect such differences using one-way ANOVA [14].
Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 20.0 (IBM Corp., Armonk, NY, USA). Qualitative variables were expressed as frequencies and percentages, whereas quantitative variables were summarized using appropriate measures of central tendency and dispersion. The Kolmogorov–Smirnov test was used to assess the normality of data distribution. Comparisons between two independent groups were performed using the Student’s t-test for normally distributed continuous variables. For comparisons among more than two groups, one-way analysis of variance (ANOVA) was applied, followed by Tukey’s post hoc test for pairwise comparisons when statistically significant differences were detected. Changes in quantitative variables over time within the same group were evaluated using the paired Student’s t-test. The Marginal Homogeneity Test was used to assess differences in ordinal variables across related stages. A p-value ≤ 0.05 was considered statistically significant. Tukey’s post hoc testing was used to reduce the risk of type I error in multiple group comparisons.
Results
Out of 104 patients inducted in our study, 90 patients met our inclusion criteria and completed the follow-up as shown in the flow diagram (Fig. 1). Demographic data comparison revealed no significant differences in sex distribution (p = 0.77), age (p = 0.76), BMI (p = 0.33) among the groups. For stone characteristics, no significant differences also were demonstrated in stone site distribution (p = 0.41), stone size (p = 0.64), stone volume (p = 0.68) stone number (p = 0.81) and stone density (p = 0.46) (Table 1).
Fig. 1.
Consort flow chart
Table 1.
Comparison between the studied groups according to demographic and stone characteristics
| Group A1 (n = 30) | Group A2 (n = 30) | Group B (n = 30) | Test of Sig. | p-value | |
|---|---|---|---|---|---|
| Sex | |||||
| Male | 22 (73.3%) | 21 (70.0%) | 20 (66.7%) | χ²=0.52 | 0.77 |
| Female | 8 (26.7%) | 9 (30.0%) | 10 (33.3%) | ||
| Age (years) | |||||
| Mean ± SD | 43.2 ± 11.5 | 42.8 ± 12.1 | 44.1 ± 11.9 | F = 0.28 | 0.76 |
| Median (IQR) | 43 (35–52) | 42 (34–53) | 44 (33–52) | ||
| BMI (kg/m²) | |||||
| Mean ± SD | 27.8 ± 4.2 | 27.0 ± 4.5 | 28.3 ± 4.0 | F = 1.11 | 0.33 |
| Median (IQR) | 28 (24–31) | 26 (24–30) | 28 (25–32) | ||
| Stone site | |||||
| Upper calyx | 9 (30.0%) | 10 (33.3%) | 8 (26.7%) | FET = 3.21 | 0.41 |
| Middle calyx | 5 (16.7%) | 4 (13.3%) | 6 (20.0%) | ||
| Lower calyx | 3 (10.0%) | 2 (6.7%) | 2 (6.7%) | ||
| Renal pelvis | 9 (30.0%) | 11 (36.7%) | 10 (33.3%) | ||
| Upper ureter | 4 (13.3%) | 3 (10.0%) | 4 (13.3%) | ||
| Stone size (mm) | |||||
| Mean ± SD | 17.4 ± 5.9 | 16.8 ± 6.2 | 17.1 ± 6.0 | H = 0.89 | 0.64 |
| Median (IQR) | 17 (12–22) | 16 (12–21) | 17 (12–22) | ||
| Stone volume (mm³) | |||||
| Mean ± SD | 1120 ± 930 | 1095 ± 910 | 1075 ± 945 | H = 0.77 | 0.68 |
| Median (IQR) | 890 (450–1650) | 870 (430–1580) | 855 (420–1600) | ||
| Stone number | |||||
| Single | 23 (76.7%) | 22 (73.3%) | 21 (70.0%) | χ²=0.43 | 0.81 |
| Multiple | 7 (23.3%) | 8 (26.7%) | 9 (30.0%) | ||
| Stone density (HU) | |||||
| Mean ± SD | 1080 ± 280 | 1110 ± 260 | 1135 ± 275 | F = 0.79 | 0.46 |
| Median (IQR) | 1070 (900–1260) | 1100 (910–1280) | 1140 (920–1300) | ||
Group A1: with standard sheath, Group A2: with suction sheath, Group B: without sheath
IQR Inter quartile range, SD Standard deviation, χ2 Chi square test, FET Fisher Exact test
F: F for One way ANOVA test, Pairwise comparison bet. each 2 groups was done using Post Hoc Test (Tukey)
H: H for Kruskal Wallis test, Pairwise comparison bet. each 2 groups was done using Post Hoc Test (Dunn’s for multiple comparisons test)
p: p value for comparing between the three studied groups
p1: p value for comparing between Group A1 and Group A2
p2: p value for comparing between Group A1 and Group B
p3: p value for comparing between Group A2 and Group B
*: Statistically significant at p ≤ 0.05
Group A2 with suction URS demonstrated the shortest operation time compared to Group A1 and Group B (p < 0.001), while no significant difference was observed between Groups A1 and B (p = 0.183). Fluoroscopy duration was similar across all groups (p = 0.187). Regarding vision quality, Group A2 had significantly better vision compared to both Group A1 and Group B (p < 0.001). Group A1 also showed a significantly better vision than Group B (p = 0.038). Ureteral injury was mucosal (Low-grade) (Clavien grade I) and did not differ significantly among the groups (p = 0.122) (Table 2).
Table 2.
Comparison between the studied groups according to operative parameters
| Group A1 (n = 30) |
Group A2 (n = 30) |
Group B (n = 30) |
Test of Sig. | p-value | |
|---|---|---|---|---|---|
| Time of operation (min.) | |||||
| Min. – Max. | 70.0–170.0 | 50.0–85.0 | 80.0–180.0 |
F = 47.082* |
< 0.001* |
| Mean ± SD. | 114.3 ± 27.0 | 70.10 ± 10.32 | 125.0 ± 28.01 | ||
| Median (IQR) | 120.0(90.0–140.0) | 70.0 (60.0–80.0) | 120.0(100.0–150.0) | ||
| Sig. bet. grps. | p1<0.001*, p2 = 0.183, p3 < 0.001* | ||||
| Time of fluoroscopy (min.) | |||||
| Min. – Max. | 3.0–9.0 | 4.0–7.0 | 3.0–9.0 |
F = 1.708 |
0.187 |
| Mean ± SD. | 6.23 ± 1.25 | 5.63 ± 0.89 | 5.87 ± 1.57 | ||
| Median (IQR) | 6.0 (5.0–7.0) | 5.50 (5.0–6.0) | 5.50 (5.0–7.0) | ||
| Vision | |||||
| 3 | 12 (40.0%) | 0 (0.0%) | 20 (66.7%) |
FET = 42.198* |
< 0.001* |
| 4 | 18 (60.0%) | 22 (73.3%) | 10 (33.3%) | ||
| 5 | 0 (0.0%) | 8 (26.7%) | 0 (0.0%) | ||
| Sig. bet. grps. | p1<0.001*,p2 = 0.038*,p3 < 0.001* | ||||
| Ureteral injury (Mucosal - Clavien grade I) | |||||
| No | 29 (96.7%) | 30 (100.0%) | 26 (86.7%) |
FET = 4.473 |
0.122 |
| Yes | 1 (3.3%) | 0 (0.0%) | 4 (13.3%) | ||
Group A1: with standard sheath, Group A2: with suction sheath, Group B: without sheath
IQR Inter quartile range, SD Standard deviation, FET Fisher Exact test
F: F for One way ANOVA test, Pairwise comparison bet. each 2 groups was done using Post Hoc Test (Tukey)
p: p value for comparing between the three studied groups
p1: p value for comparing between Group A1 and Group A2
p2: p value for comparing between Group A1 and Group B
p3: p value for comparing between Group A2 and Group B
*: Statistically significant at p ≤ 0.05
After 6 weeks of post-operative follow-up, the residual stone rates differed significantly among the groups (p = 0.035), with Group B having the highest incidence (26.7%) compared to Group A1 (10.0%) and Group A2 (3.3%). The difference was statistically significant between Groups A2 and B (p = 0.011), while no significant differences were identified between Groups A1 and A2 or A1 and B. Postoperative outcomes showed that the need for a second procedure was significantly higher in Group B (26.7%) compared to Group A1 (10.0%) and absent in Group A2 (p = 0.002). Hospital stay was significantly shorter in Group A2 compared to Group A1 and Group B (p = 0.005). The fever incidence (Clavien grade II) was significantly higher in Group B (23.3%) compared to Group A1 (16.7%) and absent in Group A2 (p = 0.005). No significant differences were recognized in hematuria rates (Clavien grade I) among the groups (p = 0.87) (Table 3).
Table 3.
Comparison between the studied groups according to post-operative parameters
| Group A1 (n = 30) |
Group A2 (n = 30) |
Group B (n = 30) |
Test of Sig. | p-value | |
|---|---|---|---|---|---|
| Residual stone | |||||
| No | 27 (90.0%) | 29 (96.7%) | 22 (73.3%) |
FET = 6.839* |
0.035* |
| Yes | 3 (10.0%) | 1 (3.3%) | 8 (26.7%) | ||
| Sig. bet. grps. | p1=0.301,p2 = 0.095,p3 = 0.011* | ||||
| Second procedure | |||||
| No | 27 (90.0%) | 30 (100.0%) | 22 (73.3%) |
FET = 10.021* |
0.005* |
| Yes | 3 (10.0%) | 0 (0.0%) | 8 (26.7%) | ||
| Sig. bet. grps. | p1=0.076,p2 = 0.095,p3 = 0.002* | ||||
| Hospital stay (day) | |||||
| 1 | 24 (80.0%) | 30 (100.0%) | 22 (73.3%) |
FET = 10.407* |
0.005* |
| 2 | 6 (20.0%) | 0 (0.0%) | 8 (26.7%) | ||
| Sig. bet. grps. | p1=0.010*,p2 = 0.542,p3 = 0.002* | ||||
| Fever (Clavien grade II) | |||||
| No | 25 (83.3%) | 30 (100.0%) | 23(76.7%) |
FET = 8.637* |
0.016* |
| Yes | 5 (16.7%) | 0 (0.0%) | 7(23.3%) | ||
| Sig. bet. grps. | p1=0.020*,p2 = 0.519,p3 = 0.005* | ||||
| Hematuria (Clavien grade I) | |||||
| No | 28 (93.3%) | 29 (96.7%) | 27 (90.0%) |
FET = 1.102 |
0.868 |
| Yes | 2(6.7%) | 1(3.3%) | 3(10.0%) | ||
Group A1: with standard sheath, Group A2: with suction sheath, Group B: without sheath
χ2Chi square test, FET Fisher Exact test
p: p value for comparing between the three studied groups
p1: p value for comparing between Group A1 and Group A2
p2: p value for comparing between Group A1 and Group B
p3: p value for comparing between Group A2 and Group B
*: Statistically significant at p ≤ 0.05
Discussion
Flexible ureteroscopic lithotripsy is an effective, minimally invasive treatment for renal stones, offering reduced kidney trauma and a shorter recovery period. However, its limited ability to actively clear stone fragments may lead to prolonged clearance times and an increased risk of infection [15]. In this study, we compared the safety and effectiveness of flexible ureteroscopy (fURS) with suction and standard UAS and without UAS in the management of renal and upper ureteric stones. The demographic characteristics were comparable across groups, with no significant differences in sex distribution, age and BMI. Obesity may present challenges in ureteroscopy due to positioning difficulties and reduced maneuverability within the collecting system [16]. However, studies such as those by Chew et al. [17] indicate that fURS remains effective in both obese and non-obese patients [17].
Operative parameters varied significantly across the study groups with fluoroscopy duration remained comparable among all groups. The shortest operative time was observed in Group A2 with suction UAS, with a statistically significant reduction compared to both Group A1 (with standard UAS) and Group B (without UAS). These findings align with those of Wang et al. [18] demonstrated that suction UAS significantly reduced operative time compared to traditional UAS [18], a finding corroborated also by Zhang et al. [19], who reported shorter operative times with the flexible tip suction UAS group compared to the traditional UAS group [19].
One possible explanation for the reduced operative time in our suction UAS group is the improvement in intraoperative visibility due to continuous debris clearance. Suction reduces the “snow-globe effect,” which can obscure stone fragments and hinder lithotripsy efficiency [20]. In our study, intraoperative vision quality showed significant variation among the groups. Level 5 vision (optimal clarity) was exclusively observed in Group A2 (26.7% of cases), followed by Level 4 vision. Notably, neither Group A1 nor Group B achieved Level 5 vision, while Level 4 vision was more frequently recorded in Group A1 than in Group B. Additionally, debris aspiration minimizes the need for manual fragment extraction, particularly for particles smaller than 2 mm, which would otherwise be time-consuming and impractical [21].
Mucosal Ureteral injury (Grade I) rates did not significantly differ among groups, yet it is worth mentioning that injuries were recorded in four cases in Group A1 and one case in Group A2, while none occurred in Group B. These mucosal injuries were managed by removal of access sheath and double J insertion. Azhar et al. [16] found that 8.2% of patients undergoing fURS with UAS experienced ureteral mucosal injuries, highlighting potential risks associated with its use [16].
In the postoperative period, although hematuria rates remained comparable across groups, fever incidence was notably higher in Group B. Hematuria (Grade I) was managed conservatively with fluids and hemostatic agents. Patients with fever (Grade II) were also managed conservatively by fluids, antibiotics and antipyretics with no serious outcomes. Optimizing procedural safety in ureteroscopy requires effective control of intrarenal pressure (IRP) and irrigation flow to minimize complications. High IRP increases the risk of mucosal injury and facilitates pyelovenous backflow, leading to the reabsorption of irrigation fluid including bacteria with its endotoxins, which can contribute to postoperative infections [22, 23]. Additionally, efficient removal of stone debris reduces the need for excessive scope manipulation and accessory instruments, further decreasing the risk of ureteral trauma and infection [24]. Routine postoperative stenting was adopted as part of our institutional protocol to ensure adequate urinary drainage, reduce the risk of ureteral edema and obstruction caused by instrumentation, facilitate passage of small residual fragments, and potentially decrease postoperative complications such as ureteral colic and obstruction-related infection. In total, our findings are consistent with those of Qian et al. [25] who found that postoperative systemic inflammatory response syndrome (SIRS) and fever were less frequent in patients treated with suction UAS [25].
Regarding stone clearance, residual fragments were more frequently observed in Group B with the need for a second procedure was significantly higher (26.7%) compared to Group A1 (10.0%) and absent in Group A2 (p = 0.002), suggesting that UAS used in Groups A1 and A2 may enhance stone-free rates (SFR) with suction sheath is more beneficial. Zhang et al. [19] reported higher SFRs at both postoperative day one and day 30 in suction UAS group compared to the traditional UAS group. Suction UAS continuously removes stone debris, maintaining a clearer field of view and improving fragment clearance [26]. These findings are also supported by Zhu et al. [14] and Ying et al. [27] who reported a significantly higher SFR on postoperative period in patients treated with suction UAS compared to those with traditional UAS or without UAS [14, 27].
Hospital stay was shorter in Groups A1 and A2, reflecting faster recovery. In contrast, Ying et al. [27] observed no significant differences in hospitalization duration between suction and traditional UAS groups [27]. Postoperative outcomes in our study further support the efficacy of suction techniques. Group A2 exhibited the most favorable outcomes, followed by Group A1, while Group B had higher rates of complications and the greatest need for second procedures. Finally, our study came with its limitations. First, all procedures in this study were performed by a single highly experienced surgeon to ensure procedural standardization, minimize technical variability, and allow consistent application of operative techniques across study groups. However, this approach may limit the external validity and generalizability of the findings, as outcomes may vary when procedures are performed by surgeons with different levels of experience or in different institutional settings so, future multicenter studies involving multiple surgeons with varying levels of expertise would be valuable to validate the reproducibility and broader applicability of our findings. Second, the relatively small sample size did not allow subgroup analysis to compare SFR, incidence of fever, and the possible recommendation of sheathless procedure in small versus larger stone burden. The stone burden located in more than one calyx generally indicates a more complex procedure and may negatively impact stone-free outcomes. So, future studies should consider incorporating this variable into patient stratification and outcome analysis. Third, the 5-point Likert scale used to assess intraoperative endoscopic vision quality was adopted as a subjective surgeon-reported outcome measure to evaluate overall visual satisfaction. It was selected due to its simplicity, ease of application, and its widespread use in surgical subjective outcome assessment. We recognize that the lack of formal validation and assessment of interobserver reliability represents another limitation of our study. Fourth, The intrarenal pressure (IRP) was not directly measured in our study. Fifth, Variations in patient anatomy could have influenced the results and the follow-up period may not have been sufficient to assess long-term complications like stricture formation or stone recurrence.
Conclusion
Suction ureteral access sheaths in flexible ureteroscopic lithotripsy for renal stones ≤ 3 cm and upper ureteric stones ≤ 1.5 cm was associated with improved stone clearance, reduced operative time and hospital stay, provide better endoscopic vision, minimized infectious complications and need for second procedure, compared to standard UAS or no sheath. However, outcomes may be influenced by surgeon experience and familiarity with suction-assisted systems. Prospective multicenter studies with larger sample sizes and varying surgeon experience levels are recommended.
Acknowledgements
None.
Abbreviations
- BMI
Body mass index
- fURS
Flexible ureteroscopy
- SFR
Stone free rate
- RIRS
Retrograde intrarenal surgery
- UAS
Ureteral access sheath
- UTI
Urinary tract infection
Authors’ contributions
- **F. Zanaty: ** Surgical procedure and manuscript writing.- **M. Ali: ** Data Collection and analysis- **F. Elserafy: ** Final manuscript revision- **M. Abozaid: ** Protocol development.
Funding
No funding was received to assist with the preparation of this manuscript.
Data availability
The datasets used and analyzed during the current study are available from the corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
All procedures were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by Menoufia University – Faculty of medicine ethics committee with number 18/2023UROL2. Informed consent was obtained from all individual participants included in the study.
Consent for publication
Written informed consent for publication of clinical details and any identifying images was obtained from all participants. Patients consented to the use of their clinical data for research and publication purposes while maintaining anonymity.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets used and analyzed during the current study are available from the corresponding author upon reasonable request.