Endoscopic stenting using endoscopic retrograde cholangiopancreatography (ERCP) is the standard of care for palliative management for patients with malignant distal biliary obstruction (MDBO). Although ERCP has high success rates, there is a 5%–9.8% rate of adverse events (AEs),¹ particularly acute pancreatitis,² and in 5%–10% of cases, this procedure fails to achieve biliary drainage (BD) even when performed by an experienced surgeon.³ Surgery or percutaneous trans-hepatic BD (PTBD) was considered the traditional treatment option for these patients. However, the recent ESGE guidelines published in 2022 have strongly recommended endoscopic ultrasound-guided BD (EUS-BD) over PTBD, as it offers comparable efficacy and better quality of life with a high safety profile.⁴

EUS-BD has gained popularity worldwide since it was reported in 2001,⁵ even in developing countries,⁶ with accumulating evidence of its favorable technical and clinical outcomes. Although major AEs, such as bile leaks and even lethal complications, have been reported,⁷ the incidence of these AEs has decreased in more recent publications due to the growing learning curve and increased experience among practitioners.⁸ EUS-guided choledochoduodenostomy (CDS) has been reported to have an acceptable success rate with minimal re-intervention and pancreatitis rates, without precluding curative surgery.⁷ Furthermore, recent studies have discussed the possibility of using EUS-BD as an emerging first-line drainage modality in patients with MDBO.^8–12

Thus, the aim of this prospective study, conducted in a relatively low-resource Middle Eastern country, was to explore the feasibility, efficacy, and outcomes of primary drainage using EUS-CDS versus ERCP for MDBO cases.

Patients and study design

From May 2021 to April 2023, this prospective non-randomized study was carried out at three Egyptian tertiary medical centers: the Specialized Medical Hospital at Mansoura University, the Theodor Bilharz Research Institute, and the Egyptian Liver Hospital. Seventy-three patients diagnosed with MDBO were selected to undergo either EUS-CDS or ERCP. Due to the staggered timing of patient involvement and the multiple centers involved, structured randomization using established methods proved challenging. Instead, patients were consecutively enrolled based on their time of presentation to ensure equal distribution across both study arms, and an electronic database was updated progressively to minimize selection bias. Patients presenting with high-up biliary obstruction, benign biliary strictures, uncorrected coagulopathy, and severe comorbidities that precluded endoscopic procedures were excluded from the study. Collected data included patient baseline demographics, the etiology of obstruction, characteristics and location of the malignant stricture, pre-procedural common bile duct (CBD) diameter, bilirubin levels before and after the procedure, the type of stent used, duration of the procedure, technical and clinical success rates, endoscopic AEs, length of hospital stay, and the necessity for stent repositioning or short-term re-intervention within 3 months after the procedure.

The study protocol received approval from the Institutional Review Board of the Egyptian Liver Hospital (Approval No. CR2021/05). This research adhered to the principles of the 1975 Declaration of Helsinki (6th revision, 2008) and followed the Consolidated Good Clinical Practice guidelines. Registration of the study was completed with the Pan African Clinical Trial Registry (https://pactr.samrc.ac.za/Search.aspx) database (identification number: PACTR202203635372753). All authors had full access to the study data and participated in the review and approval of the final manuscript. Informed written consent was secured from all participants after ensuring confidentiality and providing detailed explanations of the study's methodology, potential benefits, and possible complications or AEs associated with the planned procedures.

Endoscopic procedures

All endoscopic procedures were performed by endoscopists with expertise in both ERCP and interventional EUS. These procedures were carried out under deep sedation with propofol, with monitoring by an anesthesia consultant. Prior to the procedure, patients received intravenous antibiotics—either third-generation cephalosporins or quinolones—which were continued for 3 to 5 days post-procedure.

Endoscopic ultrasound guided choledochoduodenostomy

One of two echoendoscopes was utilized: either the Pentax linear echoendoscope EG-3870UTK (PENTAX Medical) connected to a Hitachi Avius processor (Hitachi Ltd.), or the Fujifilm EG-580UT Curved Linear Endoscopic Ultrasound Scope with SU-1 (FUJIFILM Global). Following the EUS assessment of the pancreaticobiliary system, and when possible, identification and tissue acquisition of the obstructing lesion, the echoendoscope was positioned at the superior duodenal angle in the duodenal bulb. Minor adjustments were made until the dilated CBD was identified. At this stage, the scope is typically in the long position (Fig. 1A), with its tip aimed towards the hilum, which is the ideal orientation for the easy insertion of guidewires and other accessories. Misinterpretation of the cystic duct or gallbladder neck as a dilated CBD is generally avoided by tracing the CBD towards the liver hilum through counterclockwise rotation and slight downward movement. Subsequently, the appropriate puncture site was determined using Doppler Ultrasound to avoid intervening blood vessels, followed by puncturing the CBD (Fig. 1B) with a 19 G EUS-fine needle aspiration (FNA) needle (EchoTip^® needle; Cook Medical or Expect™ Slimline needle; Boston Scientific). Confirmatory aspiration of the accumulated bile was then performed. At this point, care was taken to avoid double penetration of the duodenal wall by either identifying the single muscle layer or employing the intraluminal water instillation method. The biliary tree was then opacified using diluted contrast material, and a 0.035- or 0.025-inch guidewire (Jagwire™; Boston Scientific) was inserted under EUS guidance (Fig. 1C) through the FNA needle, with the wire being maneuvered towards the intrahepatic biliary radicles. A fistulous tract was created (Fig. 1D) between the CBD and duodenum using a 6 French cystotome (Cysto Gastro Set; ENDO-FLEX GmbH). Stent deployment (Fig. 1E) was then performed, either entirely under fluoroscopic guidance with the terminal part of the stent within the scope's working channel, or using direct endoscopic vision to ensure at least 2 cm of the stent remained intraluminally, with the distal end directed towards the anal side by manipulating the delivery system (Fig. 1F). The stents used varied in length (6 cm or 8 cm) and coverage: partially covered (Wallflex™; Boston Scientific or Hanarostent^®; M.I. Tech) or half to half stent (Hanarostent^®; M.I. Tech).

Figure 1. Technique of endoscopic ultrasound (EUS)-guided choledochoduodenostomy: (A) With the scope in the duodenal bulb, the best position is the long one with probe and needle toward the liver hilum. (B) Common bile duct (CBD) puncture using a 19 G needle with subsequent contrast opacification. (C) Guidewire manipulation under EUS guidance. (D) Fistulous tract dilatation using a 6-Fr cystotome. (E) Stent deployment, with special concern to deploy the distal end inside the scope’s working channel. (F) Directing distal end of the stent towards the anal side by manipulating the delivery system.

Endoscopic retrograde cholangiopancreatography

The procedure was carried out with a Pentax Duodenoscope ED-3490TK (PENTAX Medical) connected to an EPK-i5000 processor (PENTAX Medical). Patients were positioned prone before the scope was carefully advanced to the second part of the duodenum. The major papilla was identified, and selective cannulation of the CBD was achieved using a Zebra J-tip or straight-tip guidewire (0.35/400 cm) via a papillotome (both from Boston Scientific). In cases of difficult cannulation, as defined by the ESGE criteria,¹³ an early switch to knife-guided fistulotomy or precut was made to gain access to the bile duct. Contrast medium was then injected to clearly delineate the nature of the obstruction, allowing for appropriate subsequent management. Biliary stenting was performed using various types of stents, chosen based on the length of the stricture, to ensure a secure BD.

Procedure time

In the EUS-CDS group, the procedure time was defined as the duration from the initial attempt at drainage, starting with the identification of the CBD and subsequent puncture using an EUS-FNA needle, to the complete deployment of the stent. This starting point was selected because all cases in this group underwent a comprehensive EUS examination and often involved tissue acquisition from the target lesions before attempting EUS-CDS. In the ERCP group, procedure time was measured from the moment the papilla was first contacted by the papillotome, with the goal of achieving selective biliary cannulation, until the stent was fully in place.

Outcome measures

The primary outcome of the study included the technical and clinical success of BD. Technical success was defined as the successful placement of the stent at the end of the procedure in the proper position, with one end in the biliary tree above the stricture and the other in the alimentary tract. Clinical success was defined as a 50% or more decrease in serum total bilirubin 2 weeks after the procedure or to less than 3 mg/dL after one month. Secondary outcomes included the procedural duration, occurrence of AEs, 7-day mortality, and short-term (within 3 months) re-intervention.

Adverse events

The definition and classification of endoscopic AEs were adopted from the lexicon by the American Society for Gastrointestinal Endoscopy (ASGE).¹⁴ An AE was defined as an event that causes interruption of the procedure and/or necessitates medical consultation, hospitalization, or endoscopic or surgical intervention. The severity of AEs was classified as none, mild, moderate, or severe, based on the management required. In cases with multiple AEs, the classification was based on the most serious event. AEs were considered early or late if they occurred within or after 30 days from the time of the procedure, respectively.

Statistical analysis

Categorical variables were reported as percentages for each group and compared using the chi-square test for independent samples. Continuous variables were presented as medians with interquartile ranges and compared using the Mann-Whitney U test. A statistical significance threshold was established at P < 0.05. All statistical analyses were conducted using IBM SPSS software, version 23 (IBM Corp.).

Seventy-three patients (52 males; median age, 64 years) with MDBO were enrolled over the 2-year study duration. Endoscopic BD was performed using the EUS-CDS technique in 37 patients, while in the remaining 36 patients, drainage was attempted via ERCP.

Population characteristics

The baseline demographic characteristics, comorbidities, and causes of biliary obstruction in the patients are summarized in Table 1. The median performance status of the patients was 1, with a range of 0 to 2, as determined by the Eastern Cooperative Oncology Group performance status.¹⁵ The most common cause of biliary obstruction was pancreatic head ductal adenocarcinoma, affecting 62 patients (84.9%). Partial duodenal stenosis was observed in 16 patients (21.9%). Technical details of the endoscopic drainage techniques are summarized in Table 2, and a flowchart depicting the patient cohort and the procedures utilized is shown in Fig. 2.

Table 1 . Baseline Characteristics.

Variable	Value (n = 73)
Age (yr)	64 (58–68)
Sex, male	52 (71.2)
Comorbidity
DM	6 (8.2)
HTN	10 (13.7)
IHD	8 (11.0)
Compensated cirrhosis	6 (8.2)
COPD	2 (2.7)
Performance status	1 (0–2)
Cause of biliary obstruction
Pancreatic head adenocarcinoma	62 (84.9)
Ampullary carcinoma	8 (11.0)
Others
Cholangiocarcinoma (distal)	1 (1.4)
LN metastasis	2 (2.7)
Pre-procedure CBD diameter (mm)	16 (15–18)
Partial duodenal stenosis	16 (21.9)
Primary procedure
ERCP	36 (49.3)
EUS	37 (50.7)

Values are presented as median (range) or number (%)..

DM, diabetes mellitus; HTN, hypertension; IHD, ischemic heart disease; COPD, chronic obstructive pulmonary disease; LN, lymph node; CBD, common bile duct; ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound..

Table 2 . Technical Details.

Variable	EUS (n = 37)	ERCP (n = 36)	P-value
Age (yr)	65 (55–69)	62.5 (58–67)	0.816
Sex, male	27 (73.0)	25 (69.4)	0.739
Cause of biliary obstruction
Pancreatic head mass	34 (91.9)	28 (77.8)
Ampullary tumor	3 (8.1)	5 (13.9)	0.254
Others
Cholangiocarcinoma (distal)	0 (0.0)	1 (2.8)
LN metastasis	0 (0.0)	2 (5.6)
Compensated cirrhosis	2	4
Procedure duration (min)	16 (10–60)	16 (8–42)	0.982
Type of stent used			0.113
Partially covered	33 (89.2)	27 (75.0)
Half to half	4 (10.8)	9 (25.0)
Length of stent used (cm)
6	28 (75.7)	24 (66.7)	0.474
8	9 (24.3)	11 (30.6)
10	0 (0.0)	1 (2.8)
Use of a needle knife	All cystotome		-
Yes		28 (77.8)
No		8 (22.2)

Values are presented as median (range), number (%), or number only..

The test of significance was the chi-square test or Mann–Whitney U test..

EUS, endoscopic ultrasound; ERCP, endoscopic retrograde cholangiopancreatography; LN, lymph node..

Figure 2. Flowchart of both intervention procedures: endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) or endoscopic retrograde cholangiopancreatography (ERCP). MDBO, malignant distal biliary obstruction.

Study outcomes

Throughout the study, endoscopic therapy was technically successful in 70 out of 73 patients (95.9%). The outcomes of endoscopic BD are detailed in Table 3. In the ERCP group, failed selective biliary cannulation occurred in only 2 of 36 patients, even after employing the knife precut technique. Both patients underwent a second ERCP attempt 48 hours after the initial procedure, during which biliary cannulation was achieved more easily and within a significantly shorter duration by extending the initial precut. Conversely, one patient in the EUS-CDS group experienced technical failure due to the inability to redirect the guidewire into the cystic duct after multiple attempts (Fig. 3). The EUS procedure was subsequently discontinued, and an ERCP was performed, resulting in successful deep biliary cannulation and drainage.

Table 3 . Outcome of Endoscopic Biliary Drainage.

Variable	EUS (n = 37)	ERCP (n = 36)	P-value
Technical success	36 (97.3)	34 (94.4)	0.539
Clinical success	35 (97.2)	34 (100)	0.328
Adverse events
None	28 (77.8)	31 (91.2)	0.095
Mild	8 (22.2)	2 (5.9)
Moderate	0 (0.0)	1 (2.9)
Severe	0 (0.0)	0 (0.0)
Fatal	0 (0.0)	0 (0.0)
Re-intervention
No	33 (91.7)	34 (100)	0.228
During procedure (day)
Early (< 30)	1 (1.4)	0 (0.0)
Late (> 30)	2 (2.8)	0 (0.0)
Hospital stay (day)	1 (0–5) (n = 36)	0 (0–5) (n = 34)	0.001
0	5 (13.9)	18 (52.9)
1	26 (72.2)	12 (35.3)
2	1 (2.8)	3 (8.8)
3	4 (11.1)	0 (0.0)
5	0 (0.0)	1 (2.9)
Bilirubin level
Pre-procedure	19.05 (14.6–21.4)	15 (10.5–19.8)	0.021
Post-procedure (7–10 days)	5.45 (4.0–7.37)	3.85 (2.5–5.72)	0.021
Post-procedure (1 mo)	1.35 (1.1–2.35)	1.1 (1.0–1.2)	0.001
Percent of decrease over 7 days	68.22 (61.3–77.8)	70.7 (65.0–78.6)	0.368

Values are presented as number (%) or median (range)..

The test of significance was the chi-square test or Mann–Whitney U test..

EUS, endoscopic ultrasound; ERCP, endoscopic retrograde cholangiopancreatography..

Figure 3. Case of technical failure (arrowheads) in the endoscopic ultrasound-guided choledochoduodenostomy group with the wire directed to the cystic duct with failure to re-correct its position even after multiple trials. CBD, common bile duct; CD, cystic duct.

Clinical success was achieved in the majority of cases (69/70, 98.6%). The interventions performed were associated with a significant reduction in bilirubin levels during the first week, with levels approaching normal by the end of the first month following the drainage procedure (Table 3). Of the 36 patients who underwent a technically successful EUS-CDS procedure, all but one achieved clinical success. Despite an initial decrease in serum bilirubin from 20 mg/dL to 17.5 mg/dL, and the presence of a functioning biliary stent indicated by pneumobilia and no biliary dilation on follow-up ultrasound, this patient's bilirubin levels began to rise again. The patient ultimately succumbed to disease progression within a month. In contrast, all patients in the ERCP group experienced complete clinical success.

Sixty-seven patients (34 in the CDS group and 33 in the ERCP group) underwent successful drainage within 35 minutes. In the CDS group, only two patients encountered technical difficulties while deploying the stent, which extended the total procedure time to approximately 40 and 60 minutes, respectively. In the ERCP group, one patient with an exceptionally tight distal stricture required approximately 42 minutes to achieve complete drainage. The majority of patients in both study arms either were not admitted or stayed in the hospital for only one day following the procedure (n = 61, 87.1%). In the ERCP group, the sole patient who developed post-ERCP pancreatitis (PEP) required a 5-day hospital admission. However, in the CDS group, four patients required a 3-day hospitalization due to pre-procedural acute kidney injury or persistent cholestasis.

Adverse events and short-term re-intervention

Overall, AEs were reported in 11 patients (15.1%) across all study cohorts (Table 3). These AEs were mild in 10 patients (13.7%) and included post-procedural abdominal pain and low-grade fever. The majority of these AEs occurred in the EUS group (n = 8). There was one moderate AE of acute PEP in one patient (2.4%). No severe or fatal AEs were reported. Regarding events related to the endoscopic procedure, one patient in the CDS group experienced stent malpositioning, where the uncovered portion of the half-and-half stent (6 cm) was oriented towards the alimentary side. A longer (8 cm) partially covered self-expandable metal stent was subsequently deployed (Fig. 4) through the existing stent, ensuring secure drainage without any major AEs, except for a low-grade fever that responded to antipyretics and broad-spectrum antibiotics. This same patient required delayed re-intervention at the end of the third month of follow-up due to stent occlusion by food remnants and biliary sludge. The obstruction was cleared using balloon sweeping combined with saline wash and repeated suction. Another patient from the CDS group presented with progressive gastric outlet obstructive symptoms within the follow-up period due to duodenal invasion. The deployment of a duodenal metal stent alleviated the patient’s symptoms.

Figure 4. Recovery from technical failure. (A) Case of a maldeployed 6-cm metal stent (arrowheads) during choledochoduodenostomy with subsequent deployment of a longer (8-cm partially covered metal stent) (arrow) as a rescue procedure. (B) After full deployment of the 8-cm metal stent inside the 6-cm stent.

Practicing advanced endoscopic techniques, including BD, presents numerous challenges in developing countries. These challenges stem from a lack of dedicated devices, a shortage of experienced personnel, and the high costs involved—especially significant given that most patients do not have health insurance coverage. Despite these obstacles, striving to provide these advanced medical services remains a valuable goal and a difficult target to achieve. Our recent multicenter publication on the advancements in EUS drainage techniques for distal biliary malignancy following ERCP failure over a 3-year period within the Egyptian medical community⁶ has encouraged us to prospectively assess the use of EUS-BD. We aim to assess its role primarily as an alternative to ERCP in patients with MDBO, as it appears to offer a high success rate with a lower incidence of pancreatitis¹⁰ and generally requires a shorter duration.⁸

Overall, technical and clinical success rates in the current study were established at 95.9% and 98.6% for all enrolled patients, respectively. In the EUS-CDS group, technical and clinical success rates were comparable to those in the ERCP group (97.3% and 97.2% vs. 94.4% and 100%, respectively), with no significant difference in feasibility or efficacy (P = 0.539 and 0.328, respectively). These findings are consistent with previous publications, which report technical and clinical success rates for EUS-CDS ranging from 87% to 100% and 77% to 100%, respectively.^7,10,16–19

The incidence of AEs was similar between the two study arms. Notably, post-procedural low-grade fever occurred more frequently in the CDS group (n = 8) compared to the ERCP group (n = 2), underscoring the importance of peri-procedural broad-spectrum antibiotics for EUS-guided interventions. This is particularly relevant when complete drainage is achieved, as opposed to trans-papillary drainage. This finding aligns with the ASGE guidelines,²⁰ which do not recommend antibiotic prophylaxis when complete drainage of biliary obstruction is attained through ERCP. Conversely, the 2018 guidelines for the safe performance of EUS-BD²¹ suggested antibiotic therapy only in cases of concurrent cholangitis, citing a lack of prior studies on prophylactic antibiotic use for EUS-BD. However, they acknowledged that antibiotic prophylaxis is commonly practiced in most centers worldwide for patients undergoing EUS-BD, even in the absence of cholangitis, to prevent potential peritonitis due to bile leakage.

Compared to our group's previous publication,⁶ the incidence of AEs during the EUS-BD maneuver was significantly reduced, with only one case of stent maldeployment observed. This supports the proposal that the learning curve for EUS-BD is steep and that proficiency linearly increases with the number of cases performed, potentially making it easier to master than ERCP training.²² Re-intervention was necessary in only two cases within the EUS-CDS group, and these occurred late (after more than 30 days). One of these cases required intervention not due to the EUS procedure itself but because of duodenal invasion that necessitated duodenal stenting. In contrast, the 2019 study by Nakai et al,¹⁰ reported that 10 out of 34 patients required re-intervention, and similarly, the 2020 study by Kuraoka et al¹⁶ found that 19 out of 92 cases needed re-intervention due to cholangitis. This higher rate of re-intervention may be attributed to the use of fully covered stents, which are associated with a greater risk of stent migration. In our current study, partially covered or half-covered metal stents were used in both arms of the study.

Moderate AEs, such as pancreatitis, were not observed in cases of CDS, which is a significant advantage of EUS-CDS. This technique completely avoids direct interaction with the papillary orifice of the pancreatic duct, unlike ERCP.¹⁰ However, in our cohort, there was only one case of PEP, which was managed conservatively. This low incidence may be due to the frequent early adoption of knife-assisted precut fistulotomy or sphincterotomy in 28 (77.8%) of the ERCP cases. According to a randomized controlled trial by Maharshi and Sharma²³ in 2021, which included 303 patients, primary knife precut performed by skilled practitioners resulted in a lower incidence of PEP compared to very early precut (after two failed attempts at conventional biliary cannulation). In the same context, the duration of the ERCP procedure was reduced to approximately half an hour in 33 (97.1%) of the patients.

The duration of the procedure was nearly identical between the two study groups (P = 0.982), which is likely attributable to the extensive experience of the endoscopic teams, who have significantly honed their skills in EUS-BD over recent years. This observation aligns with the findings of Tyberg et al,²⁴ who noted that proficiency in EUS-BD is expected to lead to a decrease in procedural time as more cases are completed, with expertise being suggested after approximately 100 cases. However, determining the duration of the EUS-CDS procedure and establishing a starting point was a contentious issue during the development of the study protocol. In 2020, Kuraoka et al¹⁶ calculated the procedure time from the insertion of the scope to the reorientation of the stent. Unlike the present study, they did not perform a detailed EUS examination during the same drainage session.

Another point to consider is that radiation exposure is believed to be higher during EUS-BD than during ERCP procedures, which could pose a risk to both patients and the endoscopic team. This increased exposure may result from the need for continuous fluoroscopic guidance when exchanging devices during EUS-BD, coupled with the significant concern of losing biliary access. This concern is particularly acute after tract dilatation, as losing access at this stage can lead to procedure failure and potentially catastrophic complications such as leakage, peritonitis, and the possible need for surgical intervention. Regrettably, we were unable to precisely measure the difference in radiation exposure between the two groups due to the absence of measuring devices. However, as an indirect indication of increased exposure, we occasionally had to restart the fluoroscopic machine during EUS-BD after it had automatically shut down due to prolonged use. This observation suggests that further study is warranted to investigate our hypothesis.

Post-procedure hospitalization was limited in both study arms, with approximately 87.1% of the patient cohort requiring no or only a single day of hospital stay. This reduction in hospitalization time may be attributed to the increasing proficiency with EUS-BD procedures, as opposed to the longer admissions for continuous observation that were more common in the early days of this technique. Furthermore, the lower incidence of pancreatitis in cases of EUS-CDS could have contributed to the reduced length of stay for this group, although the difference was not statistically significant when compared to the ERCP group. These findings align with those of a Korean study by Paik et al⁸ in 2018, which reported a shorter median hospital stay for patients in the EUS-BD group relative to those in the ERCP group.

Lastly, we observed that in cases of technical failure of ERCP, subsequent attempts were significantly more successful, achieving complete functional drainage. This finding aligns with the extensive research conducted by Maruta et al,²⁵ published in the prestigious journal Scientific Reports in 2022. Their study, which included 1,021 patients, reported an increase in the success rate from 94% to 98% on the second or third ERCP following an initial failure. Notably, in 30% of cases where standard cannulation techniques were unsuccessful, knife precut techniques were employed during the initial ERCP, contributing to the initial 94% success rate. It is also important to consider that most ERCP failures do not result in serious AEs, unlike EUS-BD techniques, where failure can lead to complications such as bile leakage and peritonitis, necessitating urgent surgical intervention. Conversely, when EUS-BD encounters technical difficulties, ERCP often serves as a reliable backup solution. This underscores the extensive familiarity with and deep experience in ERCP, which provides a fallback option and imposes a less stressful burden on the endoscopic team compared to the relatively new and evolving EUS interventions.

The current study has several limitations, including the lack of randomization, a short-term follow-up period of only three months, the exclusive inclusion of biliary stents while excluding the newly developed lumen-apposing metal stents, and the inability to measure indirect AEs such as radiation exposure. Despite these limitations, to the best of our knowledge, this is the first multicenter prospective comparative study on primary EUS-CDS conducted in the Middle East and Africa, encompassing a relatively modest case series.

In conclusion, even in developing countries, EUS-CDS is feasible and demonstrates comparable safety and non-inferior efficacy to ERCP when used as a primary palliative tool in MDBO cases, provided that a highly experienced team is available. However, future large-scale randomized controlled trials with long-term follow-up are necessary to reinforce our findings. These studies should place additional emphasis on indirect AEs, such as the differences in radiation exposure between the two techniques and the variation in learning curves among endoscopists.

None.

All data generated or analyzed during this study are included in this published article and readily available for share.

No potential conflict of interest relevant to this article was reported.