Objective:To explore the efficacy and safety of the ballistic-ultrasound-negative pressure three-in-one energy platform (Trilogy) for micro-channel percutaneous nephrolithotomy (mini-PCNL).Methods:A retrospective analysis was conducted on the clinical data of 140 patients with upper urinary tract stones treated at Tianjin Medical University Second Hospital from February to October 2024. All patients underwent mini-PCNL and were divided into the holmium laser group and the Trilogy group based on the stone fragmentation equipment used during the procedure. There were 69 patients in the holmium laser group and 71 in the Trilogy group. The two groups had similar mean ages (55.1±10.2 years vs. 53.4±10.8 years), male patient proportions (50 cases, 72.5% vs. 50 cases, 70.4%), body mass indices (25.2±3.6 kg/m 2 vs. 25.3±4.0 kg/m 2), incidence rates of hypertension (29 cases, 42.0% vs. 31 cases, 43.7%), diabetes (15 cases, 21.7% vs. 12 cases, 16.9%), mean cumulative stone lengths (39.2±12.6 mm vs. 35.9±14.8 mm), total stone volumes preoperatively (6 184.3±3 653.5 mm 3 vs. 5 644.9±4 173.8 mm 3), mean CT values for stones (1 138.2±264.3 HU vs. 1 151.3±208.0 HU), stone locations (ureter 14 cases, 20.3% vs. 22 cases, 31.0%; kidney 48 cases, 69.6% vs. 39 cases, 54.9%; both ureter and kidney 7 cases, 10.1% vs. 10 cases, 14.1%), preoperative mean urinary white blood cell counts [9.6(3.6, 31.2) cells/HPF vs. 11.9(3.8, 34.5) cells/HPF], proportions of patients with preoperative urinary white blood cells (+ + + ; 23 cases, 33.3% vs. 25 cases, 35.2%), nitrite positivity rates (4 cases, 5.8% vs. 3 cases, 4.2%), and urine culture positivity rates (12 cases, 17.4% vs. 18 cases, 25.4%) showed no statistically significant differences. The proportion of patients with moderate or higher hydronephrosis in the holmium laser group was lower than that in the Trilogy group (32 cases, 46.4% vs. 47 cases, 66.2%, P=0.018). The holmium laser group utilized holmium laser lithotripsy, where stone fragments were either flushed out with a vortex or retrieved with a stone basket. The Trilogy group employed a three-in-one energy platform to break the stones. This device incorporated pneumatic ballistic, ultrasound, and negative pressure suction capabilities within the same metallic probe, allowing the stone to be fragmented into small pieces while simultaneously performing ultrasonic negative pressure stone clearance. The parameters for the three-in-one energy platform were adjusted based on intraoperative conditions, typically setting negative pressure at 30%-50%, ultrasound power at 80%-100%, ballistic power at 80%, and frequency at 8 Hz. During the stone fragmentation process, the ballistic device fragmented the stones while ultrasound further reduced larger fragments and removed them. Some fragments that were difficult to break could also be flushed out or retrieved with a stone basket. The efficiency of stone clearance (volume of stones cleared per unit time) was compared between the two groups, as well as the stone-free rates on postoperative day 1 and day 30. Stone clearance time was defined as the duration from the start of fragmentation to the placement of the nephrostomy tube. Changes in postoperative white blood cells, hemoglobin, and albumin levels compared to preoperative levels, as well as the incidence of Clavien-Dindo complications, were compared between the two groups. Equipment failure incidents were recorded (fiber fracture in the holmium laser group indicating it could not be used; probe fracture in the Trilogy group). Patients were sub-grouped based on stone CT values into CT ≥ 1 000 HU and CT < 1 000 HU categories to compare stone clearance efficiency between the two devices within each sub-group. In the CT≥1 000 HU sub-group, there were 51 cases in the holmium laser group and 54 in the Trilogy group, there were no significant differences in preoperative total stone volume (6 785.0±3 902.3 mm 3 vs. 5 678.1±4 297.7 mm 3). In the CT < 1 000 HU sub-group, there were 18 cases in the holmium laser group and 17 in the Trilogy group. There were no significant differences between the groups in preoperative total stone volume (4 482.2±2 110.6 mm 3 vs. 5 530.9±3 845.3 mm 3). Results:The overall stone clearance efficiency in the Trilogy group was higher than that in the holmium laser group (87.9±35.7 mm 3/min vs. 77.1±24.3 mm 3/min, P=0.038). There were no significant differences in residual stone volume before discharge [5.5(0, 84.0) mm 3 vs. 5.3(0, 175.0) mm 3], stone clearance time (79.4±43.2 min vs. 66.6±49.7 min), or the proportion of patients using stone baskets during the procedure (33 cases, 47.8% vs. 36 cases, 50.7%). Postoperative changes in white blood cells, hemoglobin, and albumin compared to preoperative levels were not significantly different [(4.1±2.9)×10 9/L vs. (3.3±2.2)×10 9/L; (-2.9±10.5) g/L vs. (-1.6±9.3) g/L; (-2.5±3.6) g/L vs. (-1.8±5.0) g/L] Furthermore, there were no statistically significant differences in equipment failure rates (1 case, 1.4% vs. 4 cases, 5.6%), stone-free rates (postoperative day 1: 43 cases, 62.3% vs. 47 cases, 66.2%; postoperative day 30: 50 cases, 72.5% vs. 53 cases, 74.6%), or Clavien-Dindo complication rates (grade Ⅰ: 11 cases, 15.9% vs. 8 cases, 11.3%; grade Ⅱ: 2 cases, 2.8% vs. 0 cases; grade Ⅲ: 1 case, 1.4% vs. 0 cases). In the CT ≥ 1 000 HU sub-group, the clearance time for the holmium laser was longer than that for Trilogy (93.3±41.0 min vs. 74.6±51.9 min, P=0.044), there were no significant differences in residual stone volume before discharge [6.3(1.6, 173.8) mm 3 vs. 4.5(0, 69.0) mm 3] between the two groups. In the CT < 1 000 HU sub-group, the overall stone clearance efficiency of the Trilogy group exceeded that of the holmium laser group (134.2±38.0 mm 3/min vs. 105.5 ± 7.1 mm 3/min, P=0.004), there were no significant differences between the groups in residual stone volume before discharge [0(0, 51.1) mm 3 vs. 16.3(0, 957.2) mm 3], or stone clearance time (40.2±18.1 min vs. 39.1±27.5 min). Conclusions:In mini-PCNL surgery, the stone fragmentation efficiency of the three-in-one lithotripsy energy platform is superior to that of the holmium laser, while the overall complication rate is comparable to that of the holmium laser.

Objective:To explore the aperiodic components(1/f slopes)and their associations with cognitive impairment in patients with schizophrenia.Methods:Nineteen patients with schizophrenia according to the Interna-tional Statistical Classification of Diseases and Related Health Problem,Tenth Revision(ICD-10)and 21 normal controls were administrated the total Brief Assessment of Cognition in Schizophrenia(BACS)to measure the cogni-tive performance.The 5-minute eyes-closed and eyes-open resting EEG signals were collected and parameterized in-to aperiodic components(1/f slope).Finally,Pearson correlation was used to examine the relationships between the 1/f slope and cognition assessment scores.Results:The patients with schizophrenia had higher 1/f slope compared to HC on central location of scalp(P＜0.05).The vocal memory scores showed a significantly positive relation with 1/f slopes in patients with schizophrenia(anterior location:r=-0.68,P＜0.05;central location:r=-0.44,P＜0.05),but a significantly negative relation in normal controls(anterior location:r=0.57,P＜0.05;posterior lo-cation:r=0.54,P＜0.05).Conclusion:The 1/f slopes of EEG in schizophrenia were steeper than normal control,suggesting its strong cognitive functional significance and complex mechanisms in schizophrenia.

Objective:To investigate the distribution of CGG repeat numbers in the FMR1 gene among reproductive-age women in China, providing data reference for carrier screening and genetic counseling of Fragile X syndrome. Methods:This cross-sectional study recruited 16 610 reproductive-age women from 12 medical institutions between July 2022 and October 2023. Peripheral venous blood samples (3 mL) were collected, and genomic DNA was extracted. The number of CGG repeats in the FMR1 gene was determined using the triplet-primed polymerase chain reaction (TP-PCR) combined with capillary electrophoresis technology. Statistical analyses were performed to assess the prevalence and distribution of CGG repeat expansions. Results:Among 16 610 women of childbearing age, 5 684 (34.220%) women had the same number of CGG repeats in the two alleles of FMR1 gene, and 10 926 (65.780%) women had different numbers of repeats in the two alleles. Among the 33 220 FMR1 alleles in 16 610 women of reproductive age, the most common CGG repeat numbers were 29 [48.645% (16 160/33 220)] and 30 [26.276% (8 729/33 220)], while the most frequent CGG genotype was CGG 29/29 [24.726% (4 107/16 610)]. The CGG repeat numbers of FMR1 gene were normal in 16 498 women (99.326%). Among the 112 women (0.674%) with CGG repeat abnormities, 96 (0.578%) women were classified as intermediate carriers, 15 (0.090%) as premutation carriers, and 1 (0.006%) as a full mutation carrier, whose CGG genotype was (36, >200). Conclusion:In the general reproductive-age female population in China, the normal CGG repeat numbers of the FMR1 gene account for 99.326%, while the intermediate carrier rate is 0.578%, and the combined carrier rate of the premutation and full mutation types is 0.096%.

Objective:To investigate the distribution of CGG repeat numbers in the FMR1 gene among reproductive-age women in China, providing data reference for carrier screening and genetic counseling of Fragile X syndrome. Methods:This cross-sectional study recruited 16 610 reproductive-age women from 12 medical institutions between July 2022 and October 2023. Peripheral venous blood samples (3 mL) were collected, and genomic DNA was extracted. The number of CGG repeats in the FMR1 gene was determined using the triplet-primed polymerase chain reaction (TP-PCR) combined with capillary electrophoresis technology. Statistical analyses were performed to assess the prevalence and distribution of CGG repeat expansions. Results:Among 16 610 women of childbearing age, 5 684 (34.220%) women had the same number of CGG repeats in the two alleles of FMR1 gene, and 10 926 (65.780%) women had different numbers of repeats in the two alleles. Among the 33 220 FMR1 alleles in 16 610 women of reproductive age, the most common CGG repeat numbers were 29 [48.645% (16 160/33 220)] and 30 [26.276% (8 729/33 220)], while the most frequent CGG genotype was CGG 29/29 [24.726% (4 107/16 610)]. The CGG repeat numbers of FMR1 gene were normal in 16 498 women (99.326%). Among the 112 women (0.674%) with CGG repeat abnormities, 96 (0.578%) women were classified as intermediate carriers, 15 (0.090%) as premutation carriers, and 1 (0.006%) as a full mutation carrier, whose CGG genotype was (36, >200). Conclusion:In the general reproductive-age female population in China, the normal CGG repeat numbers of the FMR1 gene account for 99.326%, while the intermediate carrier rate is 0.578%, and the combined carrier rate of the premutation and full mutation types is 0.096%.

Objective:To explore the aperiodic components(1/f slopes)and their associations with cognitive impairment in patients with schizophrenia.Methods:Nineteen patients with schizophrenia according to the Interna-tional Statistical Classification of Diseases and Related Health Problem,Tenth Revision(ICD-10)and 21 normal controls were administrated the total Brief Assessment of Cognition in Schizophrenia(BACS)to measure the cogni-tive performance.The 5-minute eyes-closed and eyes-open resting EEG signals were collected and parameterized in-to aperiodic components(1/f slope).Finally,Pearson correlation was used to examine the relationships between the 1/f slope and cognition assessment scores.Results:The patients with schizophrenia had higher 1/f slope compared to HC on central location of scalp(P＜0.05).The vocal memory scores showed a significantly positive relation with 1/f slopes in patients with schizophrenia(anterior location:r=-0.68,P＜0.05;central location:r=-0.44,P＜0.05),but a significantly negative relation in normal controls(anterior location:r=0.57,P＜0.05;posterior lo-cation:r=0.54,P＜0.05).Conclusion:The 1/f slopes of EEG in schizophrenia were steeper than normal control,suggesting its strong cognitive functional significance and complex mechanisms in schizophrenia.

Objective:To explore the efficacy and safety of the ballistic-ultrasound-negative pressure three-in-one energy platform (Trilogy) for micro-channel percutaneous nephrolithotomy (mini-PCNL).Methods:A retrospective analysis was conducted on the clinical data of 140 patients with upper urinary tract stones treated at Tianjin Medical University Second Hospital from February to October 2024. All patients underwent mini-PCNL and were divided into the holmium laser group and the Trilogy group based on the stone fragmentation equipment used during the procedure. There were 69 patients in the holmium laser group and 71 in the Trilogy group. The two groups had similar mean ages (55.1±10.2 years vs. 53.4±10.8 years), male patient proportions (50 cases, 72.5% vs. 50 cases, 70.4%), body mass indices (25.2±3.6 kg/m 2 vs. 25.3±4.0 kg/m 2), incidence rates of hypertension (29 cases, 42.0% vs. 31 cases, 43.7%), diabetes (15 cases, 21.7% vs. 12 cases, 16.9%), mean cumulative stone lengths (39.2±12.6 mm vs. 35.9±14.8 mm), total stone volumes preoperatively (6 184.3±3 653.5 mm 3 vs. 5 644.9±4 173.8 mm 3), mean CT values for stones (1 138.2±264.3 HU vs. 1 151.3±208.0 HU), stone locations (ureter 14 cases, 20.3% vs. 22 cases, 31.0%; kidney 48 cases, 69.6% vs. 39 cases, 54.9%; both ureter and kidney 7 cases, 10.1% vs. 10 cases, 14.1%), preoperative mean urinary white blood cell counts [9.6(3.6, 31.2) cells/HPF vs. 11.9(3.8, 34.5) cells/HPF], proportions of patients with preoperative urinary white blood cells (+ + + ; 23 cases, 33.3% vs. 25 cases, 35.2%), nitrite positivity rates (4 cases, 5.8% vs. 3 cases, 4.2%), and urine culture positivity rates (12 cases, 17.4% vs. 18 cases, 25.4%) showed no statistically significant differences. The proportion of patients with moderate or higher hydronephrosis in the holmium laser group was lower than that in the Trilogy group (32 cases, 46.4% vs. 47 cases, 66.2%, P=0.018). The holmium laser group utilized holmium laser lithotripsy, where stone fragments were either flushed out with a vortex or retrieved with a stone basket. The Trilogy group employed a three-in-one energy platform to break the stones. This device incorporated pneumatic ballistic, ultrasound, and negative pressure suction capabilities within the same metallic probe, allowing the stone to be fragmented into small pieces while simultaneously performing ultrasonic negative pressure stone clearance. The parameters for the three-in-one energy platform were adjusted based on intraoperative conditions, typically setting negative pressure at 30%-50%, ultrasound power at 80%-100%, ballistic power at 80%, and frequency at 8 Hz. During the stone fragmentation process, the ballistic device fragmented the stones while ultrasound further reduced larger fragments and removed them. Some fragments that were difficult to break could also be flushed out or retrieved with a stone basket. The efficiency of stone clearance (volume of stones cleared per unit time) was compared between the two groups, as well as the stone-free rates on postoperative day 1 and day 30. Stone clearance time was defined as the duration from the start of fragmentation to the placement of the nephrostomy tube. Changes in postoperative white blood cells, hemoglobin, and albumin levels compared to preoperative levels, as well as the incidence of Clavien-Dindo complications, were compared between the two groups. Equipment failure incidents were recorded (fiber fracture in the holmium laser group indicating it could not be used; probe fracture in the Trilogy group). Patients were sub-grouped based on stone CT values into CT ≥ 1 000 HU and CT < 1 000 HU categories to compare stone clearance efficiency between the two devices within each sub-group. In the CT≥1 000 HU sub-group, there were 51 cases in the holmium laser group and 54 in the Trilogy group, there were no significant differences in preoperative total stone volume (6 785.0±3 902.3 mm 3 vs. 5 678.1±4 297.7 mm 3). In the CT < 1 000 HU sub-group, there were 18 cases in the holmium laser group and 17 in the Trilogy group. There were no significant differences between the groups in preoperative total stone volume (4 482.2±2 110.6 mm 3 vs. 5 530.9±3 845.3 mm 3). Results:The overall stone clearance efficiency in the Trilogy group was higher than that in the holmium laser group (87.9±35.7 mm 3/min vs. 77.1±24.3 mm 3/min, P=0.038). There were no significant differences in residual stone volume before discharge [5.5(0, 84.0) mm 3 vs. 5.3(0, 175.0) mm 3], stone clearance time (79.4±43.2 min vs. 66.6±49.7 min), or the proportion of patients using stone baskets during the procedure (33 cases, 47.8% vs. 36 cases, 50.7%). Postoperative changes in white blood cells, hemoglobin, and albumin compared to preoperative levels were not significantly different [(4.1±2.9)×10 9/L vs. (3.3±2.2)×10 9/L; (-2.9±10.5) g/L vs. (-1.6±9.3) g/L; (-2.5±3.6) g/L vs. (-1.8±5.0) g/L] Furthermore, there were no statistically significant differences in equipment failure rates (1 case, 1.4% vs. 4 cases, 5.6%), stone-free rates (postoperative day 1: 43 cases, 62.3% vs. 47 cases, 66.2%; postoperative day 30: 50 cases, 72.5% vs. 53 cases, 74.6%), or Clavien-Dindo complication rates (grade Ⅰ: 11 cases, 15.9% vs. 8 cases, 11.3%; grade Ⅱ: 2 cases, 2.8% vs. 0 cases; grade Ⅲ: 1 case, 1.4% vs. 0 cases). In the CT ≥ 1 000 HU sub-group, the clearance time for the holmium laser was longer than that for Trilogy (93.3±41.0 min vs. 74.6±51.9 min, P=0.044), there were no significant differences in residual stone volume before discharge [6.3(1.6, 173.8) mm 3 vs. 4.5(0, 69.0) mm 3] between the two groups. In the CT < 1 000 HU sub-group, the overall stone clearance efficiency of the Trilogy group exceeded that of the holmium laser group (134.2±38.0 mm 3/min vs. 105.5 ± 7.1 mm 3/min, P=0.004), there were no significant differences between the groups in residual stone volume before discharge [0(0, 51.1) mm 3 vs. 16.3(0, 957.2) mm 3], or stone clearance time (40.2±18.1 min vs. 39.1±27.5 min). Conclusions:In mini-PCNL surgery, the stone fragmentation efficiency of the three-in-one lithotripsy energy platform is superior to that of the holmium laser, while the overall complication rate is comparable to that of the holmium laser.

Objective To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale,multicenter carrier screening.Methods This study was conducted among a total of 33 104 participants(16 610 females)from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods.Results The overall combined carrier frequency was 55.58%for 197 autosomal genes and 1.84%for 26 X-linked genes in these participants.Among the 16 669 families,874 at-risk couples(5.24%)were identified.Specifically,584 couples(3.50%)were at risk for autosomal genes,306(1.84%)for X-linked genes,and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A,393 couples),HBA1/HBA2(α-thalassemia,36 couples),PAH(phenylketonuria,14 couples),and SMN1(spinal muscular atrophy,14 couples).The most frequently detected X-linked at-risk genes were G6PD(G6PD deficiency,236 couples),DMD(Duchenne muscular dystrophy,23 couples),and FMR1(fragile X syndrome,17 couples).After excluding GJB2 c.109G>A,the detection rate of at-risk couples was 3.91%(651/16 669),which was lowered to 1.72%(287/16 669)after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95%of at-risk couples,while screening for the top 54 genes further increased the detection rate to over 99%.Conclusion This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing,genetic counseling for specific genes or gene variants can be challenging,and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

Objective To explore the mediating role of eating disorders in the relationship between body image satisfaction and anxiety symptoms among college students,and further examine the moderating effect of mindfulness on this mediating pathway.Methods By using convenience sampling,we conducted baseline and follow-up surveys among freshmen and sophomores at two universities in Xizang Autonomous Region from September to December 2021.Measurements included the Generalized Anxiety Disorder Scale,the body image satisfaction subscale of the Multidimensional Body-Self Relations Questionnaire,the Eating Attitudes Test,and the Mindful Attention Awareness Scale.Data analyses performed using SPSS 23.0 included Pearson correlation analysis,mediation(model 4),and moderation(model 58)effect analysis.Results A total of 2 993 students participated in both the baseline and follow-up surveys,including 1 007 males(34.3％)and 1,666 Tibetan and other ethnic minorities(56.8％),with an average age of 19.8(SD=1.3)years.Body image satisfaction significantly predicted anxiety symptoms,and this relationship was partially mediated by disordered eating.The presence of mindfulness moderated the impact of body image satisfaction on disordered eating and the influence of disordered eating on anxiety symptoms,indicating varying strengths of these relationships at different levels of mindfulness.Conclusion This study demonstrates that body image satisfaction can significantly predict anxiety symptoms,with disordered eating playing a mediating role in this relationship.The moderating effect of mindfulness further reveals that students with high levels of mindfulness are less likely to experience eating disorders influenced by body image dissatisfaction.Interventions for college students'mental health should consider including management of body image and eating behaviors,as well as mindfulness training.

Objective To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale,multicenter carrier screening.Methods This study was conducted among a total of 33 104 participants(16 610 females)from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods.Results The overall combined carrier frequency was 55.58%for 197 autosomal genes and 1.84%for 26 X-linked genes in these participants.Among the 16 669 families,874 at-risk couples(5.24%)were identified.Specifically,584 couples(3.50%)were at risk for autosomal genes,306(1.84%)for X-linked genes,and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A,393 couples),HBA1/HBA2(α-thalassemia,36 couples),PAH(phenylketonuria,14 couples),and SMN1(spinal muscular atrophy,14 couples).The most frequently detected X-linked at-risk genes were G6PD(G6PD deficiency,236 couples),DMD(Duchenne muscular dystrophy,23 couples),and FMR1(fragile X syndrome,17 couples).After excluding GJB2 c.109G>A,the detection rate of at-risk couples was 3.91%(651/16 669),which was lowered to 1.72%(287/16 669)after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95%of at-risk couples,while screening for the top 54 genes further increased the detection rate to over 99%.Conclusion This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing,genetic counseling for specific genes or gene variants can be challenging,and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.

Objective:To investigate the feasibility and safety of a treatment system for stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath.Methods:The clinical data of 72 patients with upper urinary calculi admitted to the Second Hospital of Tianjin Medical University from November 2022 to February 2023 were retrospectively analyzed. All patients achieved stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath. There were 50 males and 22 females. The average age was (54.7±12.1) years. Preoperative urine culture was positive in 14 cases, negative in 3 cases (4.2%)with nitrite positive, and 11 cases were negative for urine culture and nitrites but positive of white blood cells (+ + + ). There were 29 cases of renal calculi, 33 cases of upper ureteral calculi, and 10 cases of upper ureteral calculi combined with renal calculi.The mean stone diameter was 17.0(14.0, 24.0)mm. CT value was (1 049.3±258.6)HU. Twenty-four patients carried ureteral stents before operation. A total of 42 cases used ureteral sheaths with diameters of F11/13, and 30 cases used sheaths with diameters of F12/14.During the operation, an infusion pump was used to provide sufficient irrigation pressure. The negative pressure suction was attached to the distal end of the sheath. The flexible head of the sheath was guided to the target renal calyx, to completely aspirate stone fragments. Stone baskets was used in 11 cases during the procedure. The level of ureteral injury was assessed according to the Traxer grading system at the end of the operation. A ureteral stent with extraction string was retained.On the first day postoperatively, CT scanning was performed to evaluate the residual stone fragments. Patients were discharged on postoperative day 2-3 after the removal of the ureteral stent and catheter. Follow-up was conducted for 30 days postoperatively, during which the Ureteral Stent Symptom Questionnaire (USSQ) was used to assess voiding symptoms and pain. Painkiller usage and emergency revisit situations were recorded. CT scans were performed to evaluate the stone-free rate on postoperative day 30.Results:The average operation time was 30.0 (20.0, 44.5) minutes. A total of 70 cases had no ureteral injuries, and 2 cases had Grade 1 ureteral injuries (minor mucosal damage). Three cases developed fever within 72 hours postoperatively, with no cases of septic shock or fever after stent removal. Eight patients reported waist and abdominal discomfort after discharge and took oral pain medication. Among them, one patient returned to the emergency department for pain treatment. Five patients reported moderate or severe genitourinary symptoms (including voiding frequency, nocturia, urgency/incontinence, dysuria, hematuria, and incomplete emptying) based on subjective evaluation. All patients could work and recovered a normal daily life after discharge and there was no readmission or additional surgical procedures. There were 61 patients achieved immediate stone-free status on the first day after surgery, and 66 patients achieved stone-free status during follow-up at 30 days postoperatively.Conclusions:Stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath is safe and feasible.