Therapeutic utility of SpyDS-guided electrohydraulic lithotripsy in treatment of intrahepatic bile duct stones: a retrospective single-center study

Therapeutic utility of SpyDS-guided electrohydraulic lithotripsy in treatment of intrahepatic bile duct stones: a retrospective single-center study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Therapeutic utility of SpyDS-guided electrohydraulic lithotripsy in treatment of intrahepatic bile duct stones: a retrospective single-center study Dong-Xu Liao, Xiao-Yu Wang, Qian Gao, Lin Yang, Xiao Li, Qin Xie, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8572729/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Background Recently, the availability of the SpyGlass DS Direct Visualization system (SpyDS) has introduced a new era in digital peroral cholangioscopy (POCS). Numerous studies have highlighted its significant advantages over the conventional SpyGlass system, enabling diverse therapeutic interventions. Therefore, this retrospective study aimed to comprehensively assess the clinical utility and safety of SpyDS-guided electrohydraulic lithotripsy (EHL) for managing intrahepatic bile duct stones (IBDS) that are not amenable to conventional endoscopic therapy. Methods In this retrospective single-center study, consecutive patients with IBDS who underwent SpyDS-guided EHL were enrolled between June 2022 and July 2025. The clinical utility of this endoscopic surgical approach was determined by the technical success rate, stone clearance rate, postoperative hospital stay, and imaging evidence before and after the operation. The incidence of adverse events and associated outcomes were thoroughly evaluated to ensure clinical safety. Results Forty-five patients (21 men, 24 women; mean age 52.9 years) with a median stone length 2 cm underwent SpyDS-guided EHL. The overall technical success rate was 88.9%, while the overall clinical success rate was 86.7%. Complete biliary stone clearance was achieved in the first session for 76.9% of patients (30/39), with only nine patients (23.1%) requiring an additional endoscopic session. The proportion of stones located in the right posterior segmental bile duct in the clinical non-success group (5/6, 83.3%) was significantly higher than that in the clinical success group (0/39, 0%), with a statistically significant difference (P < 0.001). The median total procedure time for complete stone removal was 70 minutes, and the median duration of SpyDS procedure was 29 minutes. Complication rates were observed in a total of 35.6% cases, including cholangitis in eight patients, hyperamylasemia in five patients, and abdominal pain in three patients - all resolved through conservative management without any serious complications such as hemorrhage or perforation. Conclusions SpyDS-guided EHL demonstrates promising outcomes in the management of intrahepatic calculi, showcasing its feasibility, efficacy, and safety as a potential alternative therapeutic approach for this condition. However, its applicability may be limited to non-right posterior bile duct stones. SpyGlass electrohydraulic lithotripsy intrahepatic bile duct stones retrospective study single-center Figures Figure 1 Figure 2 Figure 3 Introduction Hepatolithiasis is a common benign disorder of the biliary tract, especially in East Asia, that poses significant challenges for treatment[ 1 ]. Currently, surgical procedures remain the principal approach for managing intrahepatic bile duct stones (IBDS), including common bile duct exploration, hepatectomy, and choledochojejunostomy[ 2 , 3 ]. Although along with the advance of endoscopic equipment and technology, endoscopic retrograde cholangiopancreatography (ERCP) has increasingly replaced surgical operations and is now widely recognized as the primary procedure for treating common bile duct stones (CBDS). However, it has failed to play a role in the treatment of IBDS[ 4 , 5 ]. More recently, a new generation of digital peroral cholangioscopy (POCS) system, the SpyGlass DS Direct Visualization system (SpyDS) (Boston Scientific, Marlborough, USA) has become available, and makes it theoretically and technically possible to treat IBDS by ERCP[ 6 ]. Several studies have reported that the novel SpyDS system offers significant advantages compared to the conventional SpyGlass system, and allow performance of various diagnostic and therapeutic procedures in biliary and pancreatic diseases[ 7 – 9 ]. One notable improvement in SpyDS is its four-way steering mechanism, which facilitates access to the target bile duct. This feature allows for precise navigation through narrow and tortuous passages, improving the overall efficiency and effectiveness of procedures[ 10 ]. Additionally, SpyDS has separate working and irrigation channels, which enhance the efficiency of stone fragmentation and provide better visibility through adequate irrigation in the treatment of complex common bile duct stones. However, there is a lack of research on intrahepatic lithotripsy guided by SpyDS, despite a few studies mentioning the treatment of IBDS with ERCP[ 11 , 12 ]. Therefore, considering the important value of SpyDS in clinical practice, in the current study, we aimed to explore the clinical utility and safety of EHL for IBDS not amenable to conventional endoscopic therapy. Methods Patients In this retrospective study, between June 2022 and July 2025, a total of 71 patients with intrahepatic bile duct stones who met the inclusion criteria were initially screened. The patients were enrolled at The General Hospital of Western Theater Command (Chengdu Military General Hospital). After applying the exclusion criteria, 45 patients were finally enrolled in the study. The specific exclusion details were as follows: 10 patients had biliary stones located in the tertiary or higher intrahepatic bile ducts, 2 patients refused digital peroral cholangioscopy, 3 patients had coagulopathy, and 1 patient had a history of Billroth Ⅱ or Roux-en-Y reconstruction, resulting in a total of 16 excluded cases (Fig. 1 ). All patients were found to have IBDS by noninvasive imaging, such as abdominal ultrasound, computed tomography (CT) or magnetic resonance cholangiopancreatography (MRCP)[ 7 ]. The Institutional Review Board of the hospital approved the study protocol, and written informed consent was obtained from each patient. The inclusion criteria were the following: (1) IBDS was found by imaging examination; (2) biliary stones were located in the primary or secondary intrahepatic bile duct; (3) the corresponding bile duct orifices with no strictures; (4) unwilling or unable to take surgical operations (Fig. 2 ). The exclusion criteria included the following: (1) biliary stones were located in the tertiary or above intrahepatic bile duct; (2) combined with biliary system tumors; (3) refused to receive a digital peroral cholangioscopy; (4) coagulopathy (international normalized ratio > 1.2, partial thromboplastin time greater than twice that of the control); (5) platelet count < 50×10 9 /µL; (6) pregnancy; (7) history of Billroth II or Roux-en-Y reconstruction[ 13 ], and inability to give informed consent. Stone Study Endpoints and definitions Primary end points were technical success and clinical success. Technical success defined as the successful insertion of SpyDS into the biliary tract, and completion of IBDS clearance following EHL. Clinical success defined as successful completion of SpyDS-guided EHL with complete stone clearance (no residual stones) and no need for conversion to other treatment modalities (e.g., surgery). The secondary end points were overall stone removal rate, rate of conversion to surgery, postoperative hospital stay. Also, the incidence of adverse events, such as the post-ERCP pancreatitis (PEP), bleeding, acute cholangitis, perforation, or any other complications were evaluated to support the clinical safety. PEP was defined as the presence of pancreatitis-type pain plus a serum amylase level over three times the upper normal limit or pain plus evidence of acute pancreatitis seen on imaging studies (CT or MRI). Bleeding, perforation, and cholangitis were defined as described in the literature[ 14 ]. Endoscopic system and techniques All procedures were performed with the Olympus JF-260V duodenoscopy (Olympus Optical, Tokyo, Japan) and SpyDS (Boston Scientific Corp, Natick, MA, USA). ERCP-related consumable accessories consisted of a catheter (Olympus Medical Systems, Tokyo, Japan), 0.035-inch guide wire (Boston Scientific Corp, Natick, MA, USA), nasobiliary drainage (Nanwei, Nanjing Hengteng Electronic Technology Co., LTD, China), a basket and an extraction balloon (Boston Scientific Corp, Natick, MA, USA). The consumable accessories for SpyDS included a basket and a single-use 10Fr multi-channeled sheath (Boston Scientific Corp, Natick, MA, USA). The EHL system (Shanghai Jingcheng Medical Device Co., LTD, China) was used in all SpyDS-guided EHL. Patients received prophylactic antibiotics before the procedures. 36 patients were performed under conscious sedation, another 9 patients were performed under intravenous anesthesia, and all with continuous monitoring of pulse rate, oxygen saturation, and blood pressure. Endoscopic procedures were performed by the same experienced endoscopist in our endoscopy unit, who was trained and experienced in diagnostic and therapeutic procedures under ERCP guidance. Firstly, a duodenoscope was advanced to the ampulla of Vater, and an ERCP catheter was inserted into the bile duct. Next, a 0.035-inch guidewire was placed in the biliary tract. After cholangiography was obtained, endoscopic sphincterotomy was performed. If combined with common bile duct stones, the stones were removed by basket or extraction balloon. Then the SpyDS was inserted into the target bile duct under guidewire guidance (Fig. 3 ). Once the stone was observed within a bile duct, the EHL probe was introduced through the working channel of SpyDS with the tip aimed directly at the stone to fragment the stone into pieces (Fig. 3 ). Initial lithotripsy is performed with low voltage (50–60 V) and short intervals or single pulses. During the procedure, a clear visual field should be maintained, and parameters adjusted according to stone hardness to improve lithotripsy efficiency, while avoiding damage to the bile duct mucosa. Fragmented stones were then flushed out or removed by using conventional extraction devices, such as a balloon and/or basket. In cases where stones could not removed completely in the first procedure, a nasobiliary drainage was inserted for biliary drainage before an additional procedure was performed. If two attempts failed, the patient was referred for surgery. The standard for stone removal was that no stone residue could be observed through SpyDS in the common bile duct and the left and right hepatic ducts. Statistical methods All statistical analyses were performed using SPSS 26.0 software(SPSS, Chicago, Ill., USA), with α = 0.05 as the significance level (two-tailed test). P < 0.05 was considered statistically significant.Continuous variables were expressed as mean ± standard deviation (normally distributed) or median (interquartile range, IQR) (non-normally distributed). Categorical variables were presented as frequency (percentage) [n (%)].For intergroup comparisons: Independent samples t-test or Mann-Whitney U test was used for continuous variables (based on normality and variance homogeneity). Pearson's chi-square test or Fisher's exact test was applied for categorical variables (depending on theoretical frequency). Results Baseline Characteristics During this study period, a total of 45 patients (male:female ratio, 21:24; mean age, 52.9 years; mean body mass index, 22.9) consecutively underwent SpyDS-guided EHL for IBDS between June 2022 and July 2025 were retrospectively enrolled. The most common reasons for initial hospitalization were right upper quadrant pain, cholangitis and jaundice. In order to evaluate the distribution of IBDS, MRCP was the most commonly used test (n = 31). As assessed by imaging, the median stone length was 2 cm. 25 patients had left hepatic duct stones, 12 patients had right hepatic duct stones, and both left and right hepatic duct stones were present in 8 patients. More importantly, most of the stones were located in the secondary bile ducts. In addition, 33 patients received EST treatment with EPBD prior to lithotomy, mostly nipple incision plus a 0.8cm dilating balloon to facilitate the access of SpyDS to the bile duct. 12 patients received EST without EPBD to better protect Oddi sphincter function (Table 1 ). Table 1 The baseline characteristics of 45 patients enrolled in this study Characteristics Value(n = 45) Patients characteristics Male:Female 21:24 Age, years (` x ± s ) 52.9 ± 13.6 Body mass index (` x ± s ) 22.9 ± 3.3 Reason for initial hospitalization, n (%) Cholangitis 11(24.4%) Jaundice 8(17.8%) Right upper quadrant pain 26(57.8%) Previous examination, n (%) MRCP 31 (68.9%) CT 14 (31.1%) Stone characteristics Stone long diameter [Median (IQR)],cm 2 (1.5,2.5) Stone location, n (%) Left hepatic duct 25 (55.6%) primary intrahepatic bile duct 11 secondary intrahepatic bile duct 14 Right hepatic duct 12 (26.7%) primary intrahepatic bile duct 5 secondary intrahepatic bile duct 8 Both in left and right hepatic duct 8 (17.7%) Number of stones 1 24(53.3%) ≥ 2 21(46.7%) Ampullary interventions prior to stone removal, n (%) EPBD with EST 33 (73.3%) EST 12 (26.7%) CT: Computed tomography; MRCP: Magnetic resonance cholangiopancreatography; EST: Endoscopic sphincterotomy; EPBD: Endoscopic papillary balloon dilation. Clinical outcomes The overall technical success rate of SpyDS-guided EHL in the treatment of IBDS was 88.9%. Catheterization was completed in all cases, and good stone imaging was achieved in 40 patients. The overall clinical success rate was 86.7%, and 76.9% (30/39) of the patients successfully removed biliary calculi completely in the first treatment. Only 9 patients (23.1%) needed another endoscopic therapy due to the difficulty of the first-stage operation, more calculi and long lithotomy time, which could increase the incidence of postoperative cholangitis caused by the long operation time. In 45 patients, the mean total operative time from duodenoscope intubation to withdrawal of lithotomy was 70 min, and the median operative time for SpyDS was 29 min. Part of the conversion surgery included 5 patients with right posterior branch angulated shape, difficulty visualizing the stone with SpyDS and failure to reach the target bile duct stone. In one case, an unexpected finding in the bile duct ultimately proven malignant, thus transferring to surgery. It shows that SpyDS can also detect bile duct lesions at an early stage (Table 2 ). Table 2 The outcomes of SpyDS-guided EHL for IBDS Operation Outcomes, n (%) Value(n = 45) Overall Technical Success 40 (88.9%) Able to cannulate with delivery catheter 45 (100%) Able to adequately visualize target 40 (88.9%) Overall Clinical Success 39 (86.7%) Complete stone Removal rate 39 (86.7%) Stone removal rate in the first session 30 (66.7%) Stone removal rate in the second session 9 (20%) Median duration of procedure to complete stone removal [Median (IQR)], min 70(60.5,80) Median duration of procedure for SpyDS [Median (IQR)], min 29(20,41.5) Rate of conversion to surgery 6 (13.3%) Biopsy reveal malignant changes 1(2.2%) Fail to reach the target duct 5(11.1%) Comparison of stone-related factors between clinical success and non-success groups Table 3 . Table 3 summarizes the differences in stone-related characteristics between the clinical success (n = 39) and non-success (n = 6) groups. There was no significant difference in the median stone long diameter between the two groups [2.0 (1.5, 2.5) cm vs. 2.0 (1.4, 3.1) cm, U = 113, P = 0.909]. However, the proportion of stones located in the right posterior segmental bile duct was significantly higher in the non-success group (5/6, 83.3%) than in the success group (0/39, 0%), with a statistically significant difference (Fisher’s exact test, P < 0.001). No significant difference was observed in the number of stones (single vs. multiple) between the two groups (Fisher’s exact test, P = 0.652). Factors Clinical Success(yes)(n = 39) Clinical Success(no)(n = 6) Stat P value Stone long diameter [Median (IQR)],cm 2(1.5,2.5) 2(1.4,3.1) 113 0.909 right posterior segmental bile duct* — < 0.001 yes 0 5 no 39 1 number of stones* — 0.652 1 22 2 ≥ 2 17 4 *Fisher's exact test Mortality Rate, Further Interventions and days in hospital In this study, no patients died due to disease-specific or surgery-related events (Table 4 ). Six patients required further intervention, and four patients needed bile duct exploration because the stones were located in the right posterior bile duct and SpyDS could not reach the target site. One additional patients underwent a right hepatectomy due to the detection of a malignant lesion by SpyDS biopsy, accompanied by atrophy and calculi in the right hepatic lobe. Patients with SpyDS spent an average of seven days in the hospital compared with surgery. Table 4 The mortality rate, further interventions and days in hospital Value(n = 45) Mortality, n (%) Disease specific 0 Procedure related 0 Further interventions, n (%) 6 (13.3%) duct exploration 5 (11.1%) partial hepatectomy 1 (2.2%) Days in hospital [Median (IQR)] 7(5,8.5) Complications and adverse events After undergoing lithotripsy treatment using SpyDS, the overall complication rates were 35.6%. As depicted in Table 5 , all cases of cholangitis were transient and effectively managed through post-surgical administration of cephalosporin. Among the five patients who experienced hyperamylasemia, trypsin inhibitor and somatostatin were administered resulting in a return to normal blood amylase levels within three days. The remaining three patients promptly resolved their abdominal pain symptoms with conservative treatment. Notably, no instances of hemorrhage, perforation or other severe complications occurred during the procedure. Furthermore, there were no anesthesia-related complications observed (Table 5 ). Table 5 Complications and Adverse Events Complication, n (%) Value(n = 45) Overall Complication 16 (35.6%) PEP 0 Hyperamylasemia 5 (12%) Cholangitis 8 (20%) Hemorrhage 0 Abdominal pain 3(7.5%) Perforation 0 Abdominal infection 0 Anesthesia related 0 Arterial hypotension and ventricular tachycardia 0 PEP: Post-ERCP pancreatitis Discussion Due to its anatomical characteristics, the management of intra-hepatic cholelithiasis is more difficult than that of extra-hepatic cholelithiasis. In this study, we present one of the earliest clinical series investigating the role of SpyDS-guided electrohydraulic lithotripsy (EHL) for IBDS. Despite being a retrospective study with a limited sample size, it remains valuable in demonstrating excellent clinical efficacy and safety supported by an 88.9% technical success rate and an 86.7% clinical success rate without any significant complications. As is known, hepatolithiasis is a prevalent condition in East Asia, and surgical procedures have long been the primary treatment for this ailment[ 15 , 16 ]. However, in recent years, per-oral endoscopic techniques have gradually replaced surgical operations for hepatic calculus treatment, particularly for extrahepatic cholangiolithiasis[ 17 ]. ERCP has emerged as the preferred first-line procedure due to its low complication rate and high success rate in complete stone removal[ 18 ]. Studies indicate that there is no significant difference in recurrence rates between successful remove choledocholiths with postoperative cholangioscopy (18%), percutaneous transhepatic cholangioscopy (21%), and ERCP (25%)[ 19 , 20 ]. Nevertheless, given that the traditional ERCP techniques rely on fluoroscopy for indirect observation and ERCP-related accessories have no steering function, some IBDS may be refractory to endoscopic removal under certain circumstances. More recently, a new generation of POCS, SpyDS has been introduced widely in referral and large medical centers. Different from the conventional mother-daughter system, SpyDS has many advantages, which mainly stem from its greater manipulability with 120° field of view, 4-way tip deflection and separate working and irrigation channels[ 20 ]. In our case series, the overall technical success rate of EHL treating IBDS under SpyDS guidance was 88.9%, and the clinical success rate was 86.7%. Furthermore, 76.9% of patients achieved complete biliary stones clearance after the initial treatment, which demonstrated comparable efficacy to SpyDS in managing challenging common bile duct stones[ 21 ]. The catheterization procedure was completed in all cases, with the majority of patients undergoing minimally invasive techniques involving small papillary incision and balloon dilation. In order to preserve sphincter function, a balloon diameter of no more than 0.8cm was utilized. After entering the common bile duct, SpyDS advanced smoothly up the left hepatic duct and right anterior biliary duct. However, due to the angle of the common bile duct, stones in the right posterior biliary duct were not satisfactorily visualized and lithotomy failed in all cases where they were present. As such, surgical treatment was ultimately required. These results suggest that right posterior bile duct stones may be an independent risk factor for failure of SpyDS in treating IBDS. In addition, during lithotomy, a novel organism was identified in the wall of the bile duct in one case, with biopsy results indicating high-grade neoplasia. Consequently, the treatment strategy was promptly modified, highlighting the potential application value of SpyDS for early detection of bile duct lesions[ 22 ]. In this study, the median operative time was found to be significantly longer compared to the findings reported by Kamiyama et al. for the treatment of common bile duct stones[ 23 ]. This is due to the requirement for SpyDS to precisely navigate into either the left hepatic duct or the right hepatic duct, and in some cases, even into the secondary bile duct or beyond, in order to effectively treat stones. However, this intricate procedure poses greater surgical challenges and consumes additional time. Therefore, it can be inferred that prolonged surgical exposure is associated with a higher incidence of adverse events when utilizing SpyDS compared to classic ERCP, resulting in cumulative rates as high as 27.8%[ 23 , 24 ]. In line with previous research findings, cholangitis emerges as the predominant adverse event associated with SpyGlass DS-guided EHL for IBDS due to heightened biliary pressure resulting from frequent saline irrigation into the bile duct during procedures[ 25 , 26 ]. Notably, out of sixteen cases with adverse events, eight were diagnosed with cholangitis, which was transient and controlled through cephalosporin application following surgery. Moreover, the prevalence of hyperamylasemia is not insignificant; typically, administration of trypsin inhibitor and somatostatin promptly restores blood amylase levels to normal. Both EHL and laser lithotripsy are effective methods for the removal of challenging bile duct stones, exhibiting a clearance rate of 69%–81% in a single session and achieving a clearance rate of 97%–100% after multiple sessions[ 26 – 28 ]. Our study did not investigate SpyGlass-guided laser lithotripsy due to our center's extensive experience with EHL. In comparison to laser lithotripsy, EHL is considered more suitable for bile duct stone removal owing to its superior efficiency and safety profile. Reports suggest that laser lithotripsy may induce a drilling effect without immediate fragmentation, particularly when the laser probe tip is in close proximity to the stone surface[ 12 ]. Moreover, the equipment required for EHL is easier to maintain and less costly. Notably, our cases demonstrated successful trauma-free implementation of EHL, which resulted in shorter hospital stays compared to surgical procedures. The limitations of this current study, including its retrospective design and limited sample size, should be acknowledged. Nonetheless, it provides a comprehensive overview of initial experiences with SpyDS-guided EHL for the treatment of IBDS. In future research, prospective controlled studies are warranted to assess the cost-effectiveness and stone recurrence rate of this technique as a suitable therapy for IBDS. In conclusion, SpyDS-guided EHL demonstrates successful outcomes in the treatment of intrahepatic stones. This technique exhibits feasibility, efficacy, and safety; however, its applicability may be limited to non-right posterior bile duct stones. Conclusions SpyDS-guided EHL demonstrates promising outcomes in the management of intrahepatic calculi, showcasing its feasibility, efficacy, and safety as a potential alternative therapeutic approach for this condition. However, its applicability may be limited to non-right posterior bile duct stones. Abbreviations SpyDS SpyGlass DS Direct Visualization system POCS peroral cholangioscopy EHL electrohydraulic lithotripsy IBDS intrahepatic bile duct stones CBDS common bile duct stones ERCP endoscopic retrograde cholangiopancreatography CT computed tomography MRCP magnetic resonance cholangiopancreatography PEP post-ERCP pancreatitis Declarations Ethical approval Ethical approval to conduct the study was obtained from The Ethical Committee of the General Hospital of Western Theater Command (approval No.2022EC3-18) in accordance with the Declaration of Helsinki. Consent for publication Informed consent was given by all participants. Competing interests The authors declare that they have no competing interests. Funding This study was supported by the National Clinical Key Subject of China (Grant No. 41792113) and the Scientific Research Project of the General Hospital of Western Theater Command (Grant No. 2024-YGLC-B03). Author Contribution Dong-Xu Liao and Xiao-Yu Wang participated in the writing of the main manuscript. Yi Wen participated in the study conception and design. Qian Gao and Lin Yang participated in statistical data analysis, and interpretation. Dong-Xu Liao, Xiao Li and Qin Xie participated in preparing all the figures. Yi Wen and Hong-Yin Liang participated in the revision of the manuscript and final approval. Acknowledgements Not appliable. Clinical trial number Not applicable. Data Availability The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. References Lee JY, Kim JS, Moon JM, Lim S-A, Chung W, Lim E-H, et al. 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Role of single-operator peroral cholangioscopy in the diagnosis of indeterminate biliary lesions: A single-center, prospective study. Gastrointest Endosc. 2011;74:511–9. https://doi.org/10.1016/j.gie.2011.04.034 . Chen YK, Pleskow DK. SpyGlass single-operator peroral cholangiopancreatoscopy system for the diagnosis and therapy of bile-duct disorders: A clinical feasibility study (with video). Gastrointest Endosc. 2007;65:832–41. https://doi.org/10.1016/j.gie.2007.01.025 . McCarty TR, Gulati R, Rustagi T. Efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones: A systematic review and meta-analysis. Endoscopy. 2021;53:110–22. https://doi.org/10.1055/a-1200-8064 . Pallio S, Sinagra E, Santagati A, D’Amore F, Rossi F, Conoscenti G, et al. Digital single-operator cholangioscopy in treating difficult biliary stones: Results from a multicenter experience. Minerva Gastroenterol (Torino). 2023;69:261–7. https://doi.org/10.23736/S2724-5985.21.02892-8 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 09 Feb, 2026 Editor invited by journal 16 Jan, 2026 Editor assigned by journal 14 Jan, 2026 Submission checks completed at journal 14 Jan, 2026 First submitted to journal 11 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8572729","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":588082830,"identity":"5cbdbc50-748f-4890-bcf5-c0ed643f1a45","order_by":0,"name":"Dong-Xu Liao","email":"","orcid":"","institution":"College of Medicine, Southwest Jiaotong University","correspondingAuthor":false,"prefix":"","firstName":"Dong-Xu","middleName":"","lastName":"Liao","suffix":""},{"id":588082831,"identity":"c6bd1db3-2ecd-4b09-84f9-4cdbc0f8e371","order_by":1,"name":"Xiao-Yu Wang","email":"","orcid":"","institution":"College of Medicine, Southwest Jiaotong University","correspondingAuthor":false,"prefix":"","firstName":"Xiao-Yu","middleName":"","lastName":"Wang","suffix":""},{"id":588082832,"identity":"a6b52973-0807-43c0-b66c-923b95fffefb","order_by":2,"name":"Qian Gao","email":"","orcid":"","institution":"General Surgery Center, General Hospital of Western Theater Command","correspondingAuthor":false,"prefix":"","firstName":"Qian","middleName":"","lastName":"Gao","suffix":""},{"id":588082833,"identity":"caef3980-89db-4b3f-a165-b7eb3974f427","order_by":3,"name":"Lin Yang","email":"","orcid":"","institution":"College of Medicine, Southwest Jiaotong University","correspondingAuthor":false,"prefix":"","firstName":"Lin","middleName":"","lastName":"Yang","suffix":""},{"id":588082834,"identity":"cf187cec-87e9-4d1d-90b1-8c20ad7153fa","order_by":4,"name":"Xiao Li","email":"","orcid":"","institution":"General Surgery Center, General Hospital of Western Theater Command","correspondingAuthor":false,"prefix":"","firstName":"Xiao","middleName":"","lastName":"Li","suffix":""},{"id":588082835,"identity":"ed9a07e4-c3bc-422e-913e-c6be613fa5f3","order_by":5,"name":"Qin Xie","email":"","orcid":"","institution":"General Surgery Center, General Hospital of Western Theater Command","correspondingAuthor":false,"prefix":"","firstName":"Qin","middleName":"","lastName":"Xie","suffix":""},{"id":588082836,"identity":"a72caeb8-5c4d-40bc-a990-9c33ff9fce37","order_by":6,"name":"Hong-Yin Liang","email":"","orcid":"","institution":"General Surgery Center, General Hospital of Western Theater Command","correspondingAuthor":false,"prefix":"","firstName":"Hong-Yin","middleName":"","lastName":"Liang","suffix":""},{"id":588082837,"identity":"95b7299d-72bc-4195-a967-510b946167f4","order_by":7,"name":"Yi Wen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA10lEQVRIiWNgGAWjYBACNv7mgw8SKmx42NgbEoGMGsJa+CSOJRt8OJMmw8dz4LHBgzPHCGuRY8gxk5zZdthGTiLxmeTDFmYiHMZwxtiY50waD5tEclpFYgMbA397dwJ+LcxthY95QH7heZZ2I3GHDIPEmbMbCNhyeDPEFvYcoJYzbAwGErmEtCSYSfO2HeZhY8j/VpDYxkyMlhSw93nYOBLSGIjTAg1koF8OJEsknDnGQ9Av8v2QqLSXb29I/PijokaOv70XvxYMwEOa8lEwCkbBKBgFWAEAcktKffFIzhkAAAAASUVORK5CYII=","orcid":"","institution":"College of Medicine, Southwest Jiaotong University","correspondingAuthor":true,"prefix":"","firstName":"Yi","middleName":"","lastName":"Wen","suffix":""}],"badges":[],"createdAt":"2026-01-11 09:53:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8572729/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8572729/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102462820,"identity":"b597bd2b-8857-4e29-b70b-adcea48a0649","added_by":"auto","created_at":"2026-02-12 01:11:40","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":111632,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of Patient Enrollment and Categorization for Intrahepatic Bile Duct\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8572729/v1/698cd789028b89f83fc0f420.png"},{"id":102462821,"identity":"d6e3efd1-a9b0-40c5-9fc8-1087800c1e4f","added_by":"auto","created_at":"2026-02-12 01:11:40","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":737607,"visible":true,"origin":"","legend":"\u003cp\u003eMRCP revealed the presence of left intrahepatic bile duct stones in a patient with a history of left extrahepatic lobectomy. The arrow indicates the precise location of the stone.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-8572729/v1/686fed151094a3f72d22cb79.png"},{"id":102462822,"identity":"54e951e1-52af-427e-bced-61eb79c578ed","added_by":"auto","created_at":"2026-02-12 01:11:41","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1668909,"visible":true,"origin":"","legend":"\u003cp\u003eThe treatment of left hepatic duct calculi through SpyDS-guided electrohydraulic lithotripsy. A: the fluoroscopy revealed the presence of a filling defect in the left hepatic duct; B: the SpyDS choledochoscope was inserted into the hilar bile duct; C: the presence of stone in the bile duct was directly visualized by SpyDS choledochoscope; D: electrohydraulic lithotripsy performed under direct visualization; E: the sutures originating from the liver resection site were discovered within the stone; F: no filling defect was observed in the left hepatic duct upon fluoroscopic examination following stone removal.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-8572729/v1/617373cd6829cf539a105563.png"},{"id":103056301,"identity":"0a0a7287-a11c-4311-931d-e4a1bdd9952c","added_by":"auto","created_at":"2026-02-20 09:05:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4540637,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8572729/v1/ae6de3ff-60c8-4824-890a-23b5d069557c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Therapeutic utility of SpyDS-guided electrohydraulic lithotripsy in treatment of intrahepatic bile duct stones: a retrospective single-center study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHepatolithiasis is a common benign disorder of the biliary tract, especially in East Asia, that poses significant challenges for treatment[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Currently, surgical procedures remain the principal approach for managing intrahepatic bile duct stones (IBDS), including common bile duct exploration, hepatectomy, and choledochojejunostomy[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Although along with the advance of endoscopic equipment and technology, endoscopic retrograde cholangiopancreatography (ERCP) has increasingly replaced surgical operations and is now widely recognized as the primary procedure for treating common bile duct stones (CBDS). However, it has failed to play a role in the treatment of IBDS[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. More recently, a new generation of digital peroral cholangioscopy (POCS) system, the SpyGlass DS Direct Visualization system (SpyDS) (Boston Scientific, Marlborough, USA) has become available, and makes it theoretically and technically possible to treat IBDS by ERCP[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral studies have reported that the novel SpyDS system offers significant advantages compared to the conventional SpyGlass system, and allow performance of various diagnostic and therapeutic procedures in biliary and pancreatic diseases[\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. One notable improvement in SpyDS is its four-way steering mechanism, which facilitates access to the target bile duct. This feature allows for precise navigation through narrow and tortuous passages, improving the overall efficiency and effectiveness of procedures[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Additionally, SpyDS has separate working and irrigation channels, which enhance the efficiency of stone fragmentation and provide better visibility through adequate irrigation in the treatment of complex common bile duct stones. However, there is a lack of research on intrahepatic lithotripsy guided by SpyDS, despite a few studies mentioning the treatment of IBDS with ERCP[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTherefore, considering the important value of SpyDS in clinical practice, in the current study, we aimed to explore the clinical utility and safety of EHL for IBDS not amenable to conventional endoscopic therapy.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003eIn this retrospective study, between June 2022 and July 2025, a total of 71 patients with intrahepatic bile duct stones who met the inclusion criteria were initially screened. The patients were enrolled at The General Hospital of Western Theater Command (Chengdu Military General Hospital). After applying the exclusion criteria, 45 patients were finally enrolled in the study. The specific exclusion details were as follows: 10 patients had biliary stones located in the tertiary or higher intrahepatic bile ducts, 2 patients refused digital peroral cholangioscopy, 3 patients had coagulopathy, and 1 patient had a history of Billroth Ⅱ or Roux-en-Y reconstruction, resulting in a total of 16 excluded cases (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All patients were found to have IBDS by noninvasive imaging, such as abdominal ultrasound, computed tomography (CT) or magnetic resonance cholangiopancreatography (MRCP)[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The Institutional Review Board of the hospital approved the study protocol, and written informed consent was obtained from each patient.\u003c/p\u003e \u003cp\u003eThe inclusion criteria were the following: (1) IBDS was found by imaging examination; (2) biliary stones were located in the primary or secondary intrahepatic bile duct; (3) the corresponding bile duct orifices with no strictures; (4) unwilling or unable to take surgical operations (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The exclusion criteria included the following: (1) biliary stones were located in the tertiary or above intrahepatic bile duct; (2) combined with biliary system tumors; (3) refused to receive a digital peroral cholangioscopy; (4) coagulopathy (international normalized ratio\u0026thinsp;\u0026gt;\u0026thinsp;1.2, partial thromboplastin time greater than twice that of the control); (5) platelet count\u0026thinsp;\u0026lt;\u0026thinsp;50\u0026times;10\u003csup\u003e9\u003c/sup\u003e/\u0026micro;L; (6) pregnancy; (7) history of Billroth II or Roux-en-Y reconstruction[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], and inability to give informed consent.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eStone Study\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eEndpoints and definitions\u003c/h3\u003e\n\u003cp\u003ePrimary end points were technical success and clinical success. Technical success defined as the successful insertion of SpyDS into the biliary tract, and completion of IBDS clearance following EHL. Clinical success defined as successful completion of SpyDS-guided EHL with complete stone clearance (no residual stones) and no need for conversion to other treatment modalities (e.g., surgery). The secondary end points were overall stone removal rate, rate of conversion to surgery, postoperative hospital stay. Also, the incidence of adverse events, such as the post-ERCP pancreatitis (PEP), bleeding, acute cholangitis, perforation, or any other complications were evaluated to support the clinical safety. PEP was defined as the presence of pancreatitis-type pain plus a serum amylase level over three times the upper normal limit or pain plus evidence of acute pancreatitis seen on imaging studies (CT or MRI). Bleeding, perforation, and cholangitis were defined as described in the literature[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eEndoscopic system and techniques\u003c/h3\u003e\n\u003cp\u003eAll procedures were performed with the Olympus JF-260V duodenoscopy (Olympus Optical, Tokyo, Japan) and SpyDS (Boston Scientific Corp, Natick, MA, USA). ERCP-related consumable accessories consisted of a catheter (Olympus Medical Systems, Tokyo, Japan), 0.035-inch guide wire (Boston Scientific Corp, Natick, MA, USA), nasobiliary drainage (Nanwei, Nanjing Hengteng Electronic Technology Co., LTD, China), a basket and an extraction balloon (Boston Scientific Corp, Natick, MA, USA). The consumable accessories for SpyDS included a basket and a single-use 10Fr multi-channeled sheath (Boston Scientific Corp, Natick, MA, USA). The EHL system (Shanghai Jingcheng Medical Device Co., LTD, China) was used in all SpyDS-guided EHL.\u003c/p\u003e \u003cp\u003ePatients received prophylactic antibiotics before the procedures. 36 patients were performed under conscious sedation, another 9 patients were performed under intravenous anesthesia, and all with continuous monitoring of pulse rate, oxygen saturation, and blood pressure. Endoscopic procedures were performed by the same experienced endoscopist in our endoscopy unit, who was trained and experienced in diagnostic and therapeutic procedures under ERCP guidance. Firstly, a duodenoscope was advanced to the ampulla of Vater, and an ERCP catheter was inserted into the bile duct. Next, a 0.035-inch guidewire was placed in the biliary tract. After cholangiography was obtained, endoscopic sphincterotomy was performed. If combined with common bile duct stones, the stones were removed by basket or extraction balloon. Then the SpyDS was inserted into the target bile duct under guidewire guidance (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Once the stone was observed within a bile duct, the EHL probe was introduced through the working channel of SpyDS with the tip aimed directly at the stone to fragment the stone into pieces (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Initial lithotripsy is performed with low voltage (50\u0026ndash;60 V) and short intervals or single pulses. During the procedure, a clear visual field should be maintained, and parameters adjusted according to stone hardness to improve lithotripsy efficiency, while avoiding damage to the bile duct mucosa. Fragmented stones were then flushed out or removed by using conventional extraction devices, such as a balloon and/or basket. In cases where stones could not removed completely in the first procedure, a nasobiliary drainage was inserted for biliary drainage before an additional procedure was performed. If two attempts failed, the patient was referred for surgery. The standard for stone removal was that no stone residue could be observed through SpyDS in the common bile duct and the left and right hepatic ducts.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eStatistical methods\u003c/h3\u003e\n\u003cp\u003eAll statistical analyses were performed using SPSS 26.0 software(SPSS, Chicago, Ill., USA), with α\u0026thinsp;=\u0026thinsp;0.05 as the significance level (two-tailed test). P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (normally distributed) or median (interquartile range, IQR) (non-normally distributed). Categorical variables were presented as frequency (percentage) [n (%)].For intergroup comparisons: Independent samples t-test or Mann-Whitney U test was used for continuous variables (based on normality and variance homogeneity). Pearson's chi-square test or Fisher's exact test was applied for categorical variables (depending on theoretical frequency).\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eBaseline Characteristics\u003c/h2\u003e \u003cp\u003eDuring this study period, a total of 45 patients (male:female ratio, 21:24; mean age, 52.9 years; mean body mass index, 22.9) consecutively underwent SpyDS-guided EHL for IBDS between June 2022 and July 2025 were retrospectively enrolled. The most common reasons for initial hospitalization were right upper quadrant pain, cholangitis and jaundice. In order to evaluate the distribution of IBDS, MRCP was the most commonly used test (n\u0026thinsp;=\u0026thinsp;31). As assessed by imaging, the median stone length was 2 cm. 25 patients had left hepatic duct stones, 12 patients had right hepatic duct stones, and both left and right hepatic duct stones were present in 8 patients. More importantly, most of the stones were located in the secondary bile ducts. In addition, 33 patients received EST treatment with EPBD prior to lithotomy, mostly nipple incision plus a 0.8cm dilating balloon to facilitate the access of SpyDS to the bile duct. 12 patients received EST without EPBD to better protect Oddi sphincter function (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe baseline characteristics of 45 patients enrolled in this study\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatients characteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale:Female\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21:24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years (`\u003cem\u003ex\u003c/em\u003e\u0026thinsp;\u0026plusmn;\u0026thinsp;\u003cem\u003es\u003c/em\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.9\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBody mass index (`\u003cem\u003ex\u003c/em\u003e\u0026thinsp;\u0026plusmn;\u0026thinsp;\u003cem\u003es\u003c/em\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eReason for initial hospitalization, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCholangitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11(24.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eJaundice\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(17.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight upper quadrant pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26(57.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePrevious examination, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMRCP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31 (68.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 (31.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eStone characteristics\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eStone long diameter [Median (IQR)],cm\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (1.5,2.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eStone location, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft hepatic duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25 (55.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eprimary intrahepatic bile duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esecondary intrahepatic bile duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight hepatic duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (26.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eprimary intrahepatic bile duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003esecondary intrahepatic bile duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBoth in left and right hepatic duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (17.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNumber of stones\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24(53.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21(46.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAmpullary interventions prior to stone removal, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEPBD with EST\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33 (73.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEST\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (26.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eCT: Computed tomography; MRCP: Magnetic resonance cholangiopancreatography; EST: Endoscopic sphincterotomy; EPBD: Endoscopic papillary balloon dilation.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eClinical outcomes\u003c/h3\u003e\n\u003cp\u003eThe overall technical success rate of SpyDS-guided EHL in the treatment of IBDS was 88.9%. Catheterization was completed in all cases, and good stone imaging was achieved in 40 patients. The overall clinical success rate was 86.7%, and 76.9% (30/39) of the patients successfully removed biliary calculi completely in the first treatment. Only 9 patients (23.1%) needed another endoscopic therapy due to the difficulty of the first-stage operation, more calculi and long lithotomy time, which could increase the incidence of postoperative cholangitis caused by the long operation time. In 45 patients, the mean total operative time from duodenoscope intubation to withdrawal of lithotomy was 70 min, and the median operative time for SpyDS was 29 min. Part of the conversion surgery included 5 patients with right posterior branch angulated shape, difficulty visualizing the stone with SpyDS and failure to reach the target bile duct stone. In one case, an unexpected finding in the bile duct ultimately proven malignant, thus transferring to surgery. It shows that SpyDS can also detect bile duct lesions at an early stage (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe outcomes of SpyDS-guided EHL for IBDS\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOperation Outcomes, n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOverall Technical Success\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (88.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAble to cannulate with delivery catheter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45 (100%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAble to adequately visualize target\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (88.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOverall Clinical Success\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39 (86.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplete stone Removal rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39 (86.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone removal rate in the first session\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30 (66.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone removal rate in the second session\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian duration of procedure to complete stone\u003c/p\u003e \u003cp\u003eremoval [Median (IQR)], min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70(60.5,80)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian duration of procedure for SpyDS [Median (IQR)], min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29(20,41.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRate of conversion to surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (13.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBiopsy reveal malignant changes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1(2.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFail to reach the target duct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5(11.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eComparison of stone-related factors between clinical success and non-success groups\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003esummarizes the differences in stone-related characteristics between the clinical success (n\u0026thinsp;=\u0026thinsp;39) and non-success (n\u0026thinsp;=\u0026thinsp;6) groups. There was no significant difference in the median stone long diameter between the two groups [2.0 (1.5, 2.5) cm vs. 2.0 (1.4, 3.1) cm, U\u0026thinsp;=\u0026thinsp;113, P\u0026thinsp;=\u0026thinsp;0.909]. However, the proportion of stones located in the right posterior segmental bile duct was significantly higher in the non-success group (5/6, 83.3%) than in the success group (0/39, 0%), with a statistically significant difference (Fisher\u0026rsquo;s exact test, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). No significant difference was observed in the number of stones (single vs. multiple) between the two groups (Fisher\u0026rsquo;s exact test, P\u0026thinsp;=\u0026thinsp;0.652).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFactors\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClinical Success(yes)(n\u0026thinsp;=\u0026thinsp;39)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eClinical Success(no)(n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStat\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone long diameter\u003c/p\u003e \u003cp\u003e[Median (IQR)],cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2(1.5,2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2(1.4,3.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e113\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.909\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eright posterior segmental\u003c/p\u003e \u003cp\u003ebile duct*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026mdash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eyes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eno\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003enumber of stones*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026mdash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.652\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*Fisher's exact test\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eMortality Rate, Further Interventions and days in hospital\u003c/h2\u003e \u003cp\u003eIn this study, no patients died due to disease-specific or surgery-related events (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Six patients required further intervention, and four patients needed bile duct exploration because the stones were located in the right posterior bile duct and SpyDS could not reach the target site. One additional patients underwent a right hepatectomy due to the detection of a malignant lesion by SpyDS biopsy, accompanied by atrophy and calculi in the right hepatic lobe. Patients with SpyDS spent an average of seven days in the hospital compared with surgery.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe mortality rate, further interventions and days in hospital\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality, n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDisease specific\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedure related\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFurther interventions, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (13.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003educt exploration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (11.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epartial hepatectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (2.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDays in hospital [Median (IQR)]\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7(5,8.5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eComplications and adverse events\u003c/h2\u003e \u003cp\u003eAfter undergoing lithotripsy treatment using SpyDS, the overall complication rates were 35.6%. As depicted in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, all cases of cholangitis were transient and effectively managed through post-surgical administration of cephalosporin. Among the five patients who experienced hyperamylasemia, trypsin inhibitor and somatostatin were administered resulting in a return to normal blood amylase levels within three days. The remaining three patients promptly resolved their abdominal pain symptoms with conservative treatment. Notably, no instances of hemorrhage, perforation or other severe complications occurred during the procedure. Furthermore, there were no anesthesia-related complications observed (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComplications and Adverse Events\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplication, n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOverall Complication\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16 (35.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePEP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyperamylasemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (12%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCholangitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHemorrhage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3(7.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePerforation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbdominal infection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnesthesia related\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eArterial hypotension and ventricular tachycardia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003ePEP: Post-ERCP pancreatitis\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eDue to its anatomical characteristics, the management of intra-hepatic cholelithiasis is more difficult than that of extra-hepatic cholelithiasis. In this study, we present one of the earliest clinical series investigating the role of SpyDS-guided electrohydraulic lithotripsy (EHL) for IBDS. Despite being a retrospective study with a limited sample size, it remains valuable in demonstrating excellent clinical efficacy and safety supported by an 88.9% technical success rate and an 86.7% clinical success rate without any significant complications.\u003c/p\u003e \u003cp\u003eAs is known, hepatolithiasis is a prevalent condition in East Asia, and surgical procedures have long been the primary treatment for this ailment[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. However, in recent years, per-oral endoscopic techniques have gradually replaced surgical operations for hepatic calculus treatment, particularly for extrahepatic cholangiolithiasis[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. ERCP has emerged as the preferred first-line procedure due to its low complication rate and high success rate in complete stone removal[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Studies indicate that there is no significant difference in recurrence rates between successful remove choledocholiths with postoperative cholangioscopy (18%), percutaneous transhepatic cholangioscopy (21%), and ERCP (25%)[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Nevertheless, given that the traditional ERCP techniques rely on fluoroscopy for indirect observation and ERCP-related accessories have no steering function, some IBDS may be refractory to endoscopic removal under certain circumstances.\u003c/p\u003e \u003cp\u003eMore recently, a new generation of POCS, SpyDS has been introduced widely in referral and large medical centers. Different from the conventional mother-daughter system, SpyDS has many advantages, which mainly stem from its greater manipulability with 120\u0026deg; field of view, 4-way tip deflection and separate working and irrigation channels[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In our case series, the overall technical success rate of EHL treating IBDS under SpyDS guidance was 88.9%, and the clinical success rate was 86.7%. Furthermore, 76.9% of patients achieved complete biliary stones clearance after the initial treatment, which demonstrated comparable efficacy to SpyDS in managing challenging common bile duct stones[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The catheterization procedure was completed in all cases, with the majority of patients undergoing minimally invasive techniques involving small papillary incision and balloon dilation. In order to preserve sphincter function, a balloon diameter of no more than 0.8cm was utilized. After entering the common bile duct, SpyDS advanced smoothly up the left hepatic duct and right anterior biliary duct. However, due to the angle of the common bile duct, stones in the right posterior biliary duct were not satisfactorily visualized and lithotomy failed in all cases where they were present. As such, surgical treatment was ultimately required. These results suggest that right posterior bile duct stones may be an independent risk factor for failure of SpyDS in treating IBDS. In addition, during lithotomy, a novel organism was identified in the wall of the bile duct in one case, with biopsy results indicating high-grade neoplasia. Consequently, the treatment strategy was promptly modified, highlighting the potential application value of SpyDS for early detection of bile duct lesions[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study, the median operative time was found to be significantly longer compared to the findings reported by Kamiyama et al. for the treatment of common bile duct stones[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. This is due to the requirement for SpyDS to precisely navigate into either the left hepatic duct or the right hepatic duct, and in some cases, even into the secondary bile duct or beyond, in order to effectively treat stones. However, this intricate procedure poses greater surgical challenges and consumes additional time. Therefore, it can be inferred that prolonged surgical exposure is associated with a higher incidence of adverse events when utilizing SpyDS compared to classic ERCP, resulting in cumulative rates as high as 27.8%[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In line with previous research findings, cholangitis emerges as the predominant adverse event associated with SpyGlass DS-guided EHL for IBDS due to heightened biliary pressure resulting from frequent saline irrigation into the bile duct during procedures[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Notably, out of sixteen cases with adverse events, eight were diagnosed with cholangitis, which was transient and controlled through cephalosporin application following surgery. Moreover, the prevalence of hyperamylasemia is not insignificant; typically, administration of trypsin inhibitor and somatostatin promptly restores blood amylase levels to normal.\u003c/p\u003e \u003cp\u003eBoth EHL and laser lithotripsy are effective methods for the removal of challenging bile duct stones, exhibiting a clearance rate of 69%\u0026ndash;81% in a single session and achieving a clearance rate of 97%\u0026ndash;100% after multiple sessions[\u003cspan additionalcitationids=\"CR27\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Our study did not investigate SpyGlass-guided laser lithotripsy due to our center's extensive experience with EHL. In comparison to laser lithotripsy, EHL is considered more suitable for bile duct stone removal owing to its superior efficiency and safety profile. Reports suggest that laser lithotripsy may induce a drilling effect without immediate fragmentation, particularly when the laser probe tip is in close proximity to the stone surface[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Moreover, the equipment required for EHL is easier to maintain and less costly. Notably, our cases demonstrated successful trauma-free implementation of EHL, which resulted in shorter hospital stays compared to surgical procedures.\u003c/p\u003e \u003cp\u003eThe limitations of this current study, including its retrospective design and limited sample size, should be acknowledged. Nonetheless, it provides a comprehensive overview of initial experiences with SpyDS-guided EHL for the treatment of IBDS. In future research, prospective controlled studies are warranted to assess the cost-effectiveness and stone recurrence rate of this technique as a suitable therapy for IBDS. In conclusion, SpyDS-guided EHL demonstrates successful outcomes in the treatment of intrahepatic stones. This technique exhibits feasibility, efficacy, and safety; however, its applicability may be limited to non-right posterior bile duct stones.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eSpyDS-guided EHL demonstrates promising outcomes in the management of intrahepatic calculi, showcasing its feasibility, efficacy, and safety as a potential alternative therapeutic approach for this condition. However, its applicability may be limited to non-right posterior bile duct stones.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSpyDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSpyGlass DS Direct Visualization system\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePOCS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eperoral cholangioscopy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEHL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eelectrohydraulic lithotripsy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIBDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eintrahepatic bile duct stones\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCBDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecommon bile duct stones\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eERCP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eendoscopic retrograde cholangiopancreatography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecomputed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRCP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emagnetic resonance cholangiopancreatography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePEP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003epost-ERCP pancreatitis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthical approval\u003c/strong\u003e \u003cp\u003e Ethical approval to conduct the study was obtained from The Ethical Committee of the General Hospital of Western Theater Command (approval No.2022EC3-18) in accordance with the Declaration of Helsinki.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003e Informed consent was given by all participants.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was supported by the National Clinical Key Subject of China (Grant No. 41792113) and the Scientific Research Project of the General Hospital of Western Theater Command (Grant No. 2024-YGLC-B03).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eDong-Xu Liao and Xiao-Yu Wang participated in the writing of the main manuscript. Yi Wen participated in the study conception and design. Qian Gao and Lin Yang participated in statistical data analysis, and interpretation. Dong-Xu Liao, Xiao Li and Qin Xie participated in preparing all the figures. Yi Wen and Hong-Yin Liang participated in the revision of the manuscript and final approval.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eNot appliable.\u003c/p\u003e \u003cp\u003e \u003cb\u003eClinical trial number\u003c/b\u003e \u003c/p\u003e \u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLee JY, Kim JS, Moon JM, Lim S-A, Chung W, Lim E-H, et al. Incidence of cholangiocarcinoma with or without previous resection of liver for hepatolithiasis. 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Minerva Gastroenterol (Torino). 2023;69:261\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.23736/S2724-5985.21.02892-8\u003c/span\u003e\u003cspan address=\"10.23736/S2724-5985.21.02892-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"SpyGlass, electrohydraulic lithotripsy, intrahepatic bile duct stones, retrospective study, single-center","lastPublishedDoi":"10.21203/rs.3.rs-8572729/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8572729/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eRecently, the availability of the SpyGlass DS Direct Visualization system (SpyDS) has introduced a new era in digital peroral cholangioscopy (POCS). Numerous studies have highlighted its significant advantages over the conventional SpyGlass system, enabling diverse therapeutic interventions. Therefore, this retrospective study aimed to comprehensively assess the clinical utility and safety of SpyDS-guided electrohydraulic lithotripsy (EHL) for managing intrahepatic bile duct stones (IBDS) that are not amenable to conventional endoscopic therapy.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eIn this retrospective single-center study, consecutive patients with IBDS who underwent SpyDS-guided EHL were enrolled between June 2022 and July 2025. The clinical utility of this endoscopic surgical approach was determined by the technical success rate, stone clearance rate, postoperative hospital stay, and imaging evidence before and after the operation. The incidence of adverse events and associated outcomes were thoroughly evaluated to ensure clinical safety.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eForty-five patients (21 men, 24 women; mean age 52.9 years) with a median stone length 2 cm underwent SpyDS-guided EHL. The overall technical success rate was 88.9%, while the overall clinical success rate was 86.7%. Complete biliary stone clearance was achieved in the first session for 76.9% of patients (30/39), with only nine patients (23.1%) requiring an additional endoscopic session. The proportion of stones located in the right posterior segmental bile duct in the clinical non-success group (5/6, 83.3%) was significantly higher than that in the clinical success group (0/39, 0%), with a statistically significant difference (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The median total procedure time for complete stone removal was 70 minutes, and the median duration of SpyDS procedure was 29 minutes. Complication rates were observed in a total of 35.6% cases, including cholangitis in eight patients, hyperamylasemia in five patients, and abdominal pain in three patients - all resolved through conservative management without any serious complications such as hemorrhage or perforation.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003e SpyDS-guided EHL demonstrates promising outcomes in the management of intrahepatic calculi, showcasing its feasibility, efficacy, and safety as a potential alternative therapeutic approach for this condition. However, its applicability may be limited to non-right posterior bile duct stones.\u003c/p\u003e","manuscriptTitle":"Therapeutic utility of SpyDS-guided electrohydraulic lithotripsy in treatment of intrahepatic bile duct stones: a retrospective single-center study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-12 01:11:34","doi":"10.21203/rs.3.rs-8572729/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-02-09T08:09:57+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-16T13:59:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-14T07:41:59+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-14T07:39:04+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Surgery","date":"2026-01-11T09:34:36+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bsur","sideBox":"Learn more about [BMC Surgery](http://bmcsurg.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bsur/default.aspx","title":"BMC Surgery","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"317dc982-54ea-4045-9000-30986c986891","owner":[],"postedDate":"February 12th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-02-12T01:11:34+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-12 01:11:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8572729","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8572729","identity":"rs-8572729","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}