Abstract
Background and Objectives:
During EUS–guided hepaticogastrostomy (EUS-HGS), bile leak usually occurs in the interval between tract dilation and stent deployment. Recently, a novel partially covered self-expandable metal stent (PCSEMS) with fine gauge stent delivery system (5.9Fr) has become available. Therefore, the aim of this prospective study was to evaluate the technical feasibility of EUS-HGS using this novel stent without tract dilation and compare it with EUS-HGS with tract dilation.
Method:
Patients with biliary disease who required EUS-BD were eligible for enrollment in this study. The primary outcome was the technical success rate of stent deployment without tract dilation.
Results:
The technical success rate of the one-step technique was 92.0% (23/25). Mean procedure time was 10.1 min, and the clinical success rate was 96% (24/25). As adverse events, bile peritonitis and stent migration were observed in one patient each. As historical controls, 75 patients who underwent EUS-HGS were enrolled in this study. As adverse events, bile peritonitis was observed in eight patients and cholangitis in three patients. After propensity score matching analysis, procedure time was significantly shorter in the one-step group compared with the two-step group (9.84 vs. 19.0 min, P < 0.001). In addition, bile peritonitis as an adverse event was significantly more frequent in the two-step group than the one-step group (P = 0.018).
Conclusions:
In conclusion, EUS-HGS using this novel PCSEMS might be feasible and safe, and performance of tract dilation might influence the occurrence of bile peritonitis.
Keywords: ERCP, Malignant biliary obstruction, EUS-HGS, Tract dilation, EUS
INTRODUCTION
EUS–guided biliary drainage (EUS-BD) is a relatively well-established technique in patients with failure of or contraindications to endoscopic retrograde cholangiopancreatography (ERCP).[1,2] Among the various EUS-BD procedures, EUS-guided hepaticogastrostomy (EUS-HGS) might be indicated in patients with surgically altered anatomy. Moreover, various kinds of therapeutic procedures, such as stone removal or target biopsy, can be performed via the EUS-HGS route after formation of the endosonographically created route (ESCR).[3–8] Therefore, the frequency of performing EUS-HGS might be increasing. On the other hand, according to a recent meta-analysis, the rate of adverse events with EUS-HGS is not low,[9] although this rate has decreased compared to that in 2016.[10] Among the potential adverse events, bile leakage is the most common, and several risk factors have been identified and efforts have been made for preventing this adverse event.[11–15] The EUS-HGS procedure can be divided into four steps, namely, bile duct puncture, guidewire deployment, tract dilation and stent deployment. During EUS-HGS, bile leak usually occurs in the interval between tract dilation and stent deployment. Several researchers have attempted stent deployment without tract dilation, use of novel fully covered self-expandable metal stents (FCSEMS), and use of a fine gauge stent delivery system to overcome this issue.[13–15] However, this stent with fine gauge stent delivery system has several disadvantages, such as focal cholangitis and stent dislocation. Recently, a novel partially covered SEMS (PCSEMS) with fine gauge stent delivery system has become available. However, the technical feasibility of deploying this stent without tract dilation is unclear. Also, to the best of our knowledge, no study has compared EUS-HGS using this stent with and without tract dilation. Therefore, the aim of this prospective study was to evaluate the technical feasibility of EUS-HGS using this novel stent without tract dilation. As secondary outcomes, we compare it with EUS-HGS with tract dilation using historical group.
PATIENTS AND METHODS
Patients
The present study was a single-center, one-arm, prospective trial. Patients with biliary disease who required EUS-BD without tract dilation for treating obstructive jaundice or for antegrade treatment at our hospital from April 2024 to January 2025 were eligible for enrollment in this study. The inclusion criteria were as follows: 1) age >18 years, 2) failed ERCP, and 3) and ECOG performance status 0–2. The exclusion criteria were as follows: 1) total gastrectomy, 2) presence of ascites, 3) bleeding tendency, and 4) refusal to participate in this study. Patients who underwent EUS-HGS with tract dilation from January 2022 to March 2024, and with the same inclusion and exclusion criteria, were enrolled as historical controls. The study was conducted according to the tenets of the Declaration of Helsinki for biomedical research involving human subjects (clinical trial registration number: University Hospital Medical Information Network 000053929000049550), and all patients provided written informed consent for study participation. A priori approval for this study was given by the Human Research Committee of Osaka Medical and Pharmaceutical University (IRB No. 2023-190).
Devices and procedure protocol
Figure 1a shows 7Fr ERCP catheter, and Figure 1b shows the PCSEMS with a fine gauge stent delivery system (HANAROSTENT® Biliary Partially Covered BenefitTM: HANARO Benefit; M.I. Tech, Seoul, Korea) that was used in this study. The tip of this stent is extremely tapered and stiff. Additionally, an uncovered site is provided 1.5 cm from the distal end, which likely plays a role in preventing branch bile duct obstruction and stent dislocation. Compared with a standard ERCP catheter (MTW; Endoskopie, Wesel, Germany), the stent delivery system of the PCSEMS with a fine gauge stent delivery system is thinner (5.9Fr). In this study, stents with a diameter of 8 mm and length of 12 cm were used for EUS-HGS without tract dilation. Figure 1c shows the conventional PCSEMS (Spring Stopper; Taewoong Medical, Seoul, Korea). The distal end of this stent has a 1.5-cm uncovered portion, and the proximal end has a lumen-apposing system, which can prevent stent migration into the abdominal cavity, because the proximal end is expanded up to 16 mm and acts to oppose movement of the stent toward the abdominal cavity. The stent delivery system is 8.5Fr. In this study, a conventional stent with a diameter of 8 mm and a length of 12 cm was used for EUS-HGS in the control group that underwent EUS-HGS with tract dilation.
Figure 1.
(a) ERCP catheter (7Fr, MTW; Endoskopie, Wesel, Germany). (b) Fine gauge stent delivery system (5.9Fr, HANAROSTENT® Biliary Partially Covered BenefitTM: HANARO Benefit; M.I. Tech, Seoul, Korea). (c) Conventional stent delivery system (8.5Fr, Spring Stopper; Taewoong Medical, Seoul, Korea).
Figure 2 shows technical tips for EUS-HGS without tract dilation. In our strategy, to prevent trans-esophageal puncture, B3 puncture was first selected as the puncture site. The intrahepatic bile duct was punctured using a 19G needle (EZ Shot 3 Plus; Olympus Medical Systems, Tokyo, Japan). After successful puncture, a small amount of bile was aspirated to confirm that the needle was in the bile duct [Figure 2a]. Then, contrast medium was injected [Figure 2b] and cholangiography was performed. A 0.025-inch guidewire was subsequently inserted into the biliary tract, and PCSEMS with a fine gauge stent delivery system insertion into the biliary tract was attempted without tract dilation [Figure 2c], followed by stent deployment using the intra-scope channel release technique, as previously described[16] [Figure 2d]. If insertion of the stent delivery system failed, tract dilation was performed. Figure 3 shows technical tips for EUS-HGS with tract dilation. Briefly, after successful bile duct puncture and contrast medium injection [Figure 3a], a 0.025-inch guidewire was deployed [Figure 3b]. Then, the tract was dilated using a 4-mm balloon catheter (REN biliary balloon catheter; KANEKA, Osaka, Japan) or an ultratapered mechanical dilator (7Fr, ES dilator; Zeon Medical Inc., Tokyo, Japan) [Figure 3c]. After tract dilation, stent deployment was performed using the intrascope channel release technique [Figure 3d]. All patients underwent computed tomography after EUS-HGS, to detect early adverse events such as stent migration.
Figure 2.
Technical tips for EUS-HGS using one-step technique. (a) After successful intrahepatic bile duct puncture, the contrast medium is injected. (b) 0.025-inch guidewire is inserted into the biliary system. (c) A fine gauge stent delivery system insertion into the biliary system is successfully performed. (d) Stent deployment from the intrahepatic bile duct to the stomach is successfully performed.
Figure 3.
Technical tips for EUS-HGS using two-step technique. (a) The intrahepatic bile duct is punctured, and the contrast medium is injected. (b) 0.025-inch guidewire is inserted into the biliary tract. (c) Tract dilation is performed using 4-mm balloon catheter. (d) Stent deployment is performed.
Outcome measurements and definitions
In this study, patients were grouped as the “one-step group” (stent deployment without tract dilation) and “two-step group” (stent deployment with tract dilation). In the one-step group, who underwent EUS-HGS from April 2024 to January 2025, the novel PCSEMS with a fine gauge stent delivery system was prospectively used without tract dilation. The two-step group retrospectively enrolled as historical controls who underwent EUS-HGS using the conventional stent inserted with tract dilation during the period from January 2022 to March 2024. Because the aim of the present study was to evaluate technical feasibility, a sample size of 24 patients was deemed necessary based on a previous similar study.[17] To allow for possible patient dropout, we estimated that a final sample size of 25 patients in each group was required.
The primary outcome was the technical success rate of stent deployment without tract dilation. If stent delivery system insertion into the biliary tract failed, it was considered as technical failure. Successful stent deployment was defined as appearance of bile juice after stent deployment from the intrahepatic bile duct to the stomach. The secondary outcomes were to compare clinical outcomes between one-step and two-step groups. Clinical success was defined as a 50% decrease in bilirubin within 2 weeks post-stent insertion, or achieving a value of less than 25% of preprocedure bilirubin levels within 4 weeks post-stent insertion. Bile peritonitis was diagnosed if fever, elevated inflammatory markers on blood examination, and abdominal pain were observed the day after EUS-HGS. Postoperative bleeding events were defined as bleeding requiring blood transfusion, melena, hematemesis, bleeding confirmed on CT, or a decrease in hemoglobin by ≥2 g/dL. Adverse events were graded according to the severity grading system of the American Society for Gastrointestinal Endoscopy lexicon.[18] The length of hepatic parenchyma at the puncture site and the diameter of the puncture site were measured on EUS imaging. The angle between the guidewire and bile duct was measured by fluoroscopic imaging after guidewire deployment. During EUS-HGS, if contrast medium leakage into the abdominal cavity was observed on fluoroscopic imaging, the procedure was considered to be positive for contrast medium leakage. Procedure time was measured from the time of bile duct puncture to scope removal.
Statistical analysis
Propensity score matching was performed to create propensity scores for the one-step group and the two-step group with a logistic regression model. One-to-one matching without replacement was performed with a caliper width of 0.2, and the resulting score-matched pairs were used in the subsequent analysis. Patients were adjusted for six factors (age, sex, primary disease, length of hepatic parenchyma, and diameter of the bile duct at the puncture site). Descriptive statistics are presented as mean ± standard deviation (SD) or median and range values for continuous variables, and as frequencies for categorical variables. The two groups were compared using analysis of variance for continuous factors, the Kruskal-Wallis test for number of events, and Pearson’s chi-squared test or Fisher's exact test for categorical factors. Survival curves for stent patency or OS were estimated using Kaplan-Meier curves. Differences with a P value <0.05 were considered significant. All data were statistically analyzed using SPSS version 13.0 statistical software (SPSS, Chicago, IL, USA).
RESULTS
Characteristics of patients in the one-step group (prospective cohort)
From April 2024 to January 2025, 37 patients who required EUS-HGS were screened for possible enrolment in the present study. Among them, patients with total gastrectomy (n = 7) and those who refused to participate in the present study (n = 5) were excluded. Finally, a total of 25 patients (median age, 77 years; 10 men) who underwent EUS-HGS without tract dilation were prospectively enrolled. The primary diseases were cholangiocarcinoma (n = 8), pancreatic cancer (n = 6), metastatic cancer (n = 4), bile duct stone (n = 3), and anastomotic stricture (n = 4). The indications for EUS-HGS were surgically altered anatomy (n = 14) and duodenal stenosis (n = 11). Mean length of the hepatic parenchyma at the puncture site was 23.0 mm, and the mean diameter of the puncture site was 3.81 mm [Table 1].
Table 1.
Patient characteristics in the one-step group (prospective cohort).
| Total number of patients, n | 25 |
| Age (yr), median (range) | 77 (48–90) |
| Male:Female | 10:15 |
| Primary disease, n | |
| Cholangiocarcinoma | 8 |
| Pancreatic cancer | 6 |
| Metastatic cancer | 4 |
| Bile duct stone | 3 |
| Anastomotic stricture | 4 |
| Reason for EUS-HGS, n | |
| Surgically altered anatomy | 14 |
| Duodenal stenosis | 11 |
| Mean length of hepatic parenchyma at the puncture site, mm ± SD | 23.0 ± 7.48 |
| Number of the length of hepatic parenchyma at the puncture site <25 mm, n | 6 |
| Mean diameter of bile duct at the puncture site, mm ± SD | 3.81 ± 1.76 |
| T-bilirubin (mg/dL), mean ± SD | 5.76 ± 6.62 |
| AST (U/L), mean ± SD | 155.6 ± 127.6 |
| ALT (U/L), mean ± SD | 162.0 ± 162.5 |
| White blood cell count (/μL), mean ± SD | 6621.2 ± 2469.4 |
| C-reactive protein (mg/dL), mean ± SD | 4.70 ± 4.39 |
Clinical outcomes in the one-step group (prospective cohort)
The mean angle between the guidewire and bile duct in the one-step group was 126.4°. During the procedure, contrast medium leakage into the abdominal cavity on fluoroscopic imaging was not observed in any of the patients. The technical success rate of the one-step technique was 92.0% (23/25). In the remaining two patients, because insertion of the stent delivery system into the biliary tract failed, tract dilation was performed using a 4-mm balloon catheter, and stent deployment was successfully performed after tract dilation. Therefore, overall technical success of EUS-HGS was obtained in all of the patients. Mean procedure time was 10.1 min, and the clinical success rate was 96% (24/25). As adverse events, bile peritonitis and stent migration were observed in one patient each. The bile peritonitis was successfully treated conservatively, whereas the stent migration was successfully treated by reintervention using a through-the-mesh technique within the abdominal cavity, as previously described,[19] and the previous stent was successfully recovered without percutaneous or surgical treatment [Table 2].
Table 2.
Clinical outcomes in the one-step group (prospective cohort).
| Angle between the guidewire and bile duct (deg), mean ± SD | 126.4 ± 33.0 |
| Presence of contrast medium leakage during the procedure, % (n) | 0 (0/25) |
| Technical success rate of the one-step technique, % (n) | 92.0 (23/25) |
| Overall technical success rate of EUS-HGS | 100 (25/25) |
| Procedure time (min), mean ± SD | 10.1 ± 4.16 |
| Clinical success rate, % (n) | 96 (24/25) |
| Adverse events, n | |
| Bile peritonitis | 1 |
| Stent migration | 1 |
Characteristics and clinical outcomes of patients in the two-step group (retrospective cohort)
As historical controls, 75 patients (median age, 81 years; 49 men) who underwent EUS-HGS using the two-step technique from January 2022 to March 2024 were enrolled in this study. The primary diseases in this group were cholangiocarcinoma (n = 34), pancreatic cancer (n = 20), metastatic cancer (n = 7), bile duct stone (n = 8), and anastomotic stricture (n = 6). The indications for EUS-HGS were surgically altered anatomy (n = 35) and duodenal stenosis (n = 36). The mean length of the hepatic parenchyma at the puncture site was 21.4 mm, and diameter of the puncture site was 3.53 mm. The mean angle between the guidewire and bile duct was 126.9°. During the procedure, contrast medium leakage into the abdominal cavity on fluoroscopic imaging was observed in 13 patients (17.3%). Mean procedure time was 16.8 min. As adverse events, bile peritonitis was observed in eight patients, and cholangitis in three patients [Table 3].
Table 3.
Patient characteristics in the two-step group (retrospective cohort).
| Total number of patients, n | 75 |
| Age (yr), median (range) | 81 (48–94) |
| Male:Female | 49:26 |
| Primary disease, n | |
| Cholangiocarcinoma | 34 |
| Pancreatic cancer | 20 |
| Metastatic cancer | 7 |
| Bile duct stone | 8 |
| Anastomotic stricture | 6 |
| Reason for EUS-HGS, n | |
| Surgically altered anatomy | 39 |
| Duodenal stenosis | 36 |
| Length of hepatic parenchyma at the puncture site (mm), mean ± SD | 21.4 ± 7.14 |
| Number of the length of hepatic parenchyma at the puncture site <25 mm, n | 27 |
| Diameter of bile duct at the puncture site (mm), mean ± SD | 3.53 ± 1.43 |
| Angle between the guidewire and bile duct (deg.), mean ± SD | 126.9 ± 30.4 |
| Presence of contrast medium leakage during the procedure, % (n) | 17.3 (13/75) |
| Procedure time (min), mean ± SD | 16.8 ± 7.14 |
| T-bilirubin (mg/dL), mean ± SD | 5.43 ± 6.41 |
| AST (U/L), mean ± SD | 98.8 ± 90.9 |
| ALT (U/L), mean ± SD | 97.3 ± 90.6 |
| White blood cell count (/μL), mean ± SD | 7579.3 ± 4466.2 |
| C-reactive protein (mg/dL), mean ± SD | 5.21 ± 6.40 |
| Adverse events, n | |
| Bile peritonitis | 8 |
| Cholangitis | 3 |
| Stent migration | 0 |
Propensity score matching analysis of patient characteristics between successful one-step and two-step groups
Following exclusion of technical failure and stent migration cases, 22 technically successful patients from the one-step group were included for comparison with 22 technically successful propensity score–matched patients from the two-step group. Propensity score matching analysis demonstrated that median age, sex, primary disease, indication for EUS-HGS, mean length of hepatic parenchyma at the puncture site, mean diameter of the bile duct at the puncture site, and mean angle between the guidewire and bile duct were not significantly different between the two groups. On the other hand, although there were no significant differences, contrast medium leakage into the abdominal cavity during the procedure was more frequently observed in the two-step group (18.2%) compared to the one-step group (0%) (P = 0.053). Further, procedure time was significantly shorter in the one-step group compared with the two-step group (9.84 vs. 19.0 min, P < 0.001). In addition, bile peritonitis as an adverse event was significantly more frequent in the two-step group than the one-step group (P = 0.018) [Table 4].
Table 4.
Propensity score matching analysis of patient characteristics between successful one-step and two-step groups.
| One-step group | Two-step group | P value | |
|---|---|---|---|
| Total number of patients, n | 22 | 22 | — |
| Age (yr), median (range) | 77 (45–90) | 79.5 (56–87) | 0.397 |
| Male:Female | 8:14 | 6:16 | 0.517 |
| Primary disease | |||
| Malignant disease/Benign disease | 17:5 | 17: 5 | 1.00 |
| Reason for EUS-HGS | |||
| Surgically altered anatomy/Duodenal stenosis | 12:10 | 13:9 | 0.761 |
| Length of hepatic parenchyma at the puncture site (mm), mean ± SD | 22.7 ± 7.13 | 22.9 ± 7.87 | 0.769 |
| Number of the length of hepatic parenchyma at the puncture site <25 mm | 2 | 2 | 1.000 |
| Diameter of bile duct at the puncture site (mm), mean ± SD | 3.79 ± 1.88 | 3.84 ± 1.70 | 0.972 |
| Angle between the needle and guidewire (deg.), mean ± SD | 125.3 ± 31.6 | 124.0 ± 35.9 | 0.981 |
| Presence of contrast medium leakage during the procedure, % (n) | 0 (0/22) | 18.2 (4/22) | 0.053 |
| Procedure time (min), mean ± SD | 9.84 ± 4.03 | 19.0 ± 9.20 | <0.001 |
| Bile peritonitis, n | 0/22 | 5/22 | 0.018 |
DISCUSSION
In the present study, the technical success rate of EUS-HGS without tract dilation using the novel PCSEMS with fine gauge stent delivery system was high. Compared with the two-step group, procedure time was significantly shorter with the one-step procedure. Moreover, the rate of bile peritonitis was also significantly lower in the one-step group. To the best of our knowledge, this study is the first prospective evaluation study of the novel stent, and our study showed that tract dilation influences the occurrence of bile peritonitis during EUS-HGS. There are several notable points of our study, such as the technical feasibility of EUS-HGS without tract dilation and the frequency of bile peritonitis.
To date, several authors have conducted retrospective technical feasibility studies on EUS-HGS without tract dilation.[13,20,21] According to these studies, the technical success rate of EUS-HGS without tract dilation was nearly 100%. On the other hand, in the present study, technical success of EUS-HGS could not be obtained without tract dilation in all patents. There are two possible explanations for this observation. The first reason might be the pushing ability and the tip shape of the stent delivery system. Takeshita et al. retrospectively evaluated the technical feasibility of EUS-BD using a 7Fr stent delivery system without tract dilation.[20] Although only three EUS-HGS cases were included in their study, technical success was obtained in all of the patients. On the other hand, we used a 5.9Fr stent delivery system in the present study. The pushing ability of the 7Fr stent delivery system might be stronger than that of the 5.9Fr stent delivery system. Therefore, the pushing ability of the stent delivery system might influence its successful insertion into the biliary tract. Park et al. also conducted a prospective randomized trial of EUS-HGS with and without tract dilation.[21] In their study, although the 7Fr stent delivery system provided a 4Fr tapered metal tip for simple puncture of the intestinal wall and liver parenchyma, the technical success rate was 88% (14/16). The most suitable shape of the tip, therefore, is still unclear. Further clinical trials are needed to evaluate the ideal tip shape and diameter of the stent delivery system for successful performance of EUS-HGS without tract dilation. The second reason for the limited technical success without tract dilation in this study might be the angle between the guidewire and bile duct, which would have influenced device insertion into the biliary tract.[22,23] Fujii et al. performed multivariate analysis to evaluate the efficacy of the double guidewire technique for EUS-HGS, focusing on the guidewire angle at the insertion site.[22] In their study, a guidewire angle of ≤137° (odds ratio, 35.6; 95% confidence interval, 1.70–744; P = 0.0045) and intrahepatic bile duct diameter at the puncture site of ≤3.0 mm (odds ratio, 14.4; 95% confidence interval, 1.37–152; P = 0.0056) were risk factors for the need for additional fistula dilation. According to another study,[23] when the mean angle between the bile duct and guidewire was 128.6°, the technical success rate of device insertion was 80.4% (115/143). However, after the moving scope technique, the mean angle between the bile duct and guidewire improved to 141.0°, and the technical success rate of device insertion also improved to 99.3% (142/143). On the other hand, in the present study, although the angle between the bile duct and guidewire was 126.4°, EUS-HGS without tract dilation was successful in most cases. This discrepancy suggests that the factors related to successful EUS-HGS without tract dilation need further evaluation, including stiffness of the guidewire, thickness of the stomach and bile duct wall, and penetration ability of the stent delivery system.
According to several meta-analyses, bile peritonitis associated with bile leakage is one of the most common adverse events of EUS-HGS.[1,9,10] Theoretically, this adverse event occurs due to bile leakage from the puncture route among each procedural step. Several methods have been reported for preventing bile peritonitis.[11,12,24] Compared with the transduodenal approach, such as in EUS-guided choledochoduodenostomy or gallbladder drainage, hepatic parenchyma exerts a tamponade effect in EUS-HGS. However, this effect requires the bile duct puncture to be performed across sufficient hepatic parenchyma. We previously evaluated risk factors for bile peritonitis as an adverse effect of EUS-HGS.[12] That study showed that a hepatic parenchyma length of 2.50 cm offered 90.3% sensitivity and 87.5% specificity in predicting bile peritonitis according to receiver operating characteristic curve analysis. According to univariate analysis, number of punctures (>1), procedure time (>20 min), length of hepatic parenchyma (<2.50 cm), and presence of acute cholangitis were significantly associated with bile peritonitis. However, multivariate analysis showed that only the length of hepatic parenchyma (<2.50 cm; odds ratio, 96.98; 95% confidence interval, 10.12–929.12; P < 0.001) was significantly associated with bile peritonitis. However, in clinical practice, bile duct puncture across this length might not always be possible. Indeed, in the present study, the mean length of hepatic parenchyma at the puncture site in each group was less than 2.5 cm. Ishiwatari et al. investigated whether bile aspiration during EUS-HGS decreased the rate of postprocedural adverse events.[11] In their study, the quantity of bile aspirated was 0–10 and >10 mL in 40 and 56 patients, respectively. They found that the rate of adverse events was 65% (26/40) and 34% (19/56) with aspiration of 0–10 and >10 mL of bile, respectively (P = 0.004). Additionally, multivariate analysis demonstrated aspirated bile amount of 0–10 mL as being the only independent factor affecting the occurrence of adverse events (odds ratio, 4.16; 95% confidence interval, 1.6–10.8). They suggested that bile aspiration might lead to a decrease in pressure in the biliary tree, which might also decrease bile leakage. However, in their study, bile peritonitis was not observed in any of the patients, including those without bile aspiration. Because the biliary tree includes the intrahepatic bile duct and the common bile duct, if bile is aspirated from the common bile duct, it might not lead to a significant decrease in intrahepatic bile duct pressure. Further evaluation, including the site of bile aspiration, is needed to clarify the role of bile aspiration on the development of bile leakage with EUS-HGS. Itonaga et al. conducted a retrospective comparison of EUS-BD with and without tract dilation.[24] In their study, the rate of early adverse events, such as bile leakage, was significantly lower (12% vs. 35%, P = 0.013) in EUS-BD without tract dilation than with tract dilation. In multivariate analysis, tract dilation was a significant independent risk factor for early adverse events (hazard ratio, 9.66; 95% confidence interval, 1.13–83.0; P = 0.028). Therefore, they concluded that tract dilation was a significant risk factor for early adverse events. However, their study had several limitations, such as its retrospective nature, inclusion of various types of stents and different EUS-BD procedures. On the other hand, the present study was a prospective study that only included EUS-HGS. Therefore, our findings might be significant in terms of clinical practice.
Our study has several limitations. First, although this used propensity score matching analysis, it was not a randomized trial. Second, the present study only included patients who underwent EUS-HGS using SEMS. Therefore, our findings might not be applicable to EUS-HGS using a plastic stent. Third, although the diameter of the SEMS in both groups was the same, the types of SEMS used were not. This might have influenced the radial force exerted by the stent on the bile duct wall. Exertion of a weaker radial force until full expansion of the stent might lead to bile leakage. Therefore, a randomized controlled trial using the same stent is needed to confirm our findings. Finally, frequency of bile peritonitis in two-step technique group might be high compared with previous studies. Compared with cautery dilation, the diameter of tract after dilation, especially using by balloon catheter, might be large; therefore, this might be influenced for this result. A comparison study of EUS-HGS with cautery dilation and one-step technique should be conducted.
In conclusion, EUS-HGS using this novel PCSEMS might be feasible and safe, and performance of tract dilation might influence the occurrence of bile peritonitis. Further randomized controlled trials are needed to confirm our results.
Acknowledgment
None.
Source of Funding
None.
Ethical Statements
A priori approval for this study was given by the Human Research Committee of Osaka Medical and Pharmaceutical University (IRB No. 2023-190). Informed consents were obtained from each patient.
Conflicts of Interest
T. Ogura is an Editorial Board Member of the journal. The article was subjected to the standard procedures of the journal, with a review process independent of this editor and his research group.
Author Contributions
M. Tomita and T. Ogura wrote the paper. T. Ogura, A. Hakoda, S. Ueno, A. Okuda, N. Nishioka, J. Matsuno, N. Hattori, J. Nakamura, T. Kanadani, K. Bessho, and H. Nishikawa played roles in data interpretation, revised the work critically for important intellectual content, provided final approval of the version to be published, and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Data Availability Statement
Data will be shared by author reasonable requests.
Footnotes
Published online: 26 March 2026
Contributor Information
Mitsuki Tomita, Email: amg636363@yahoo.co.jp.
Takeshi Ogura, Email: oguratakeshi0411@yahoo.co.jp.
Akitoshi Hakoda, Email: hakodokah@gmail.com.
Saori Ueno, Email: onchannopasocon@yahoo.co.jp.
Atsushi Okuda, Email: ubuntu_koromo@yahoo.co.jp.
Nobu Nishioka, Email: yumegiwa8916@yahoo.co.jp.
Jun Matsuno, Email: omcuba.0114@gmail.com.
Nobuhiro Hattori, Email: nobuhero.222@gmail.com.
Junichi Nakamura, Email: jnakamura614@outlook.jp.
Takafumi Kanadani, Email: taka.t.m.u@icloud.com.
Kimi Bessho, Email: k.bessy0730@gmail.com.
Hiroki Nishikawa, Email: nishikawa_6392_0207@yahoo.co.jp.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data will be shared by author reasonable requests.