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CC BY 4.0 · Journal of Digestive Endoscopy
DOI: 10.1055/s-0045-1814756
Narrative Review

Biliary Drainage in Altered Anatomy: A Comprehensive Literature Review

Authors

  • Rishi Chowdhary 

    1   Department of Internal Medicine-Pediatrics, MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio, United States

  • Jorge D. Machicado

    2   Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States

  • Veeral M. Oza

    3   Division of Gastroenterology, Bon Secours Mercy Health, Greenville, South California, United States
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Abstract

Endoscopic retrograde cholangiopancreatography (ERCP), introduced in 1968, remains the gold standard for managing pancreatobiliary disorders, achieving success rates of nearly 95% in patients with normal anatomy. However, modern surgical interventions, such as Roux-en-Y gastric bypass (RYGB), hepaticojejunostomy, pancreaticoduodenectomy (Whipple procedure), and Billroth II gastrectomy, result in surgically altered anatomies (SAA), complicating biliary interventions due to anatomical distortions, including long afferent limbs and sharp intestinal angulations. Device-assisted enteroscopy-based ERCP (DAE-ERCP), including double-balloon, single-balloon, and spiral enteroscopy, has improved access in SAA, especially RYGB patients, with technical success rates as high as 95%; however, it remains technically demanding and time-intensive. Laparoscopy-assisted ERCP demonstrates a higher technical success rate (>95%), but carries increased invasiveness, prolonged procedure times, and higher adverse event rates, limiting its routine use. Endoscopic ultrasound-guided biliary drainage, comprising rendezvous technique, transmural drainage such as choledochoduodenostomy (CDS) and hepaticogastrostomy (HGS), and antegrade interventions, has emerged as a reliable alternative, showing superior technical success and lower complication rates compared with percutaneous transhepatic biliary drainage. Specifically, EUS-guided transmural techniques (HGS, CDS) offer effective internal drainage in anatomies where conventional approaches fail. The recently developed EUS-directed transgastric ERCP procedure, utilizing lumen-apposing metal stents to create temporary gastro-gastric or jejuno-gastric fistulas, has revolutionized biliary interventions in RYGB, achieving high technical and clinical success rates. Novel and hybrid approaches, including magnetic compression anastomosis, artificial intelligence-assisted navigation, and biodegradable stents, continue to enhance therapeutic possibilities, underscoring an evolving multidisciplinary landscape for biliary interventions in surgically altered anatomy.


Keywords

ERCP - biliary drainage - surgically altered anatomy - device-assisted enteroscopy - EDGE procedure - EUS-guided biliary drainage - Roux-en-Y gastric bypass

Introduction

Since its inception in 1968, endoscopic retrograde cholangiopancreatography (ERCP) has been regarded as the gold standard for diagnosing and managing pancreatobiliary diseases, with success rates close to 95% in cases with normal anatomy.[1] [2] The advent of modern surgical techniques, such as Roux-en-Y gastric bypass (RYGB), hepaticojejunostomy with Roux-en-Y, pancreaticoduodenectomy (Whipple procedure), and Billroth II gastrectomy, poses increasing challenges to the successful execution of ERCP-related procedures. These surgeries result in surgically altered anatomy (SAA), characterized by long afferent limbs, acute angulations of the small bowel, and biliodigestive anastomoses (BDA), all of which complicate identification and cannulation of the biliary tract.[3]

Over recent decades, the rise in pancreaticoduodenectomies has been accompanied by biliary complications, such as biliary leaks, which occur in 2 to 9% of cases, most commonly at the site of hepaticojejunostomy.[4] With the ongoing obesity pandemic, one expects a steady increase in bariatric surgeries, and hence, the prevalence of SAA is expected to rise further.[5] Given the heightened risk of biliary complications associated with morbid obesity and rapid weight loss, the demand for technically complex endoscopic interventions in patients with SAA will continue to grow.[6]

Endoscopic access and therapeutic interventions in patients with SAA remain technically complex, often requiring device-assisted enteroscopy (DAE), laparoscopy-assisted ERCP (LA-ERCP), endoscopic-ultrasound-guided biliary drainage (EUS-BD), or percutaneous and surgical alternatives. As the prevalence of altered anatomy continues to rise due to growing surgical volumes, understanding the evolving strategies, success rates, limitations, and innovations in biliary intervention is critical.

This review aims to provide a comprehensive overview of the challenges, available techniques, and clinical outcomes associated with biliary interventions in patients with SAA.


Anatomical Considerations

Effective biliary drainage in patients with SAA primarily depends on overcoming three critical challenges: navigating the afferent limb to reach the biliopancreatoenteric anastomosis or ampulla, achieving successful cannulation of the bile or pancreatic ducts within the new anatomical orientation, and performing the necessary diagnostic or therapeutic interventions safely.[7] To guide the endoscopic approach, surgical anatomies have been grouped into two categories,[8] as shown in [Fig. 1]:

Zoom
Fig. 1 Surgically altered anatomies. Type I: (A) Billroth I gastrectomy; (B) sleeve gastrectomy. Type II: (C) Roux-en-Y gastric bypass; (D) Billroth 2 gastrectomy; (E) Whipple procedure.

Type I: In this group, the duodenum remains in continuation with the gastric remnant. This occurs in procedures where the stomach (or part of it) is still connected to the duodenum. Examples are sleeve gastrectomy (vertical sleeve resection of the stomach) and Billroth I gastrectomy (distal gastrectomy with gastroduodenostomy).

Type II: In this group, the normal gastric-duodenal pathway is disrupted, which means the duodenum and papilla are not in continuity with the upper GI tract. The stomach may be bypassed, removed, or separated from the duodenum. Examples include Billroth II gastrectomy (gastrojejunostomy with an afferent loop), RYGB for obesity (gastrojejunostomy with an excluded stomach and a long Roux limb), Roux-en-Y hepaticojejunostomy (surgical biliary bypass, often after bile duct injury, liver transplantation, or tumor), and Whipple procedure (pancreaticoduodenectomy with gastrojejunostomy and hepaticojejunostomy).[9]


Conventional Endoscopic Retrograde Cholangiopancreatography in Altered Anatomy

A side-viewing duodenoscope is typically the instrument of choice for performing ERCP due to its ability to visualize the biliary anastomosis site, allowing biliary drainage to be achieved using conventional cannulation techniques even in altered anatomy.[10]

In Type I reconstructions, those maintaining continuity between stomach and duodenum, such as Billroth I gastrectomy or sleeve gastrectomy, a standard side-viewing duodenoscope can often reach the papilla with minimal issue, with comparable success rates.[9]

However, Type II anatomies in which the duodenum is excluded or relocated (e.g., Billroth II gastrojejunostomy, RYGB, Whipple procedure) will present major challenges in maneuvering the duodenoscope to the papilla.[9] Hence, duodenoscopes, gastroscopes, and colonoscopes have been used across different studies in patients with SAA, but there is no clear consensus established regarding the optimal endoscopic approach.

In Billroth II anatomy, the difficulty arises from the challenge of selectively intubating the afferent limb due to the sharp angulation between the gastric remnant and small bowel and the limited visualization of the papilla, which is often hidden behind mucosal folds. Hence, the conventional side-viewing scope is difficult to use as it presents a side view, is rigid, and relatively large diameter, thereby increasing the risk of injury to the small bowel or gastrojejunal anastomosis.[11] Fugazza et al examined a new technique, underwater cap-assisted ERCP (u-ERCP), in which a transparent plastic cap is fitted onto the tip of a forward-viewing endoscope (gastroscope or colonoscope). In six patients with SAA, they reported 100% technical success with no adverse events.[12] Lee et al similarly evaluated the use of a cap-assisted regular colonoscope for ERCP and reported an intubation success rate of 74.4% without adverse events, with side-to-side jejunojejunostomy showing the highest rates.[13] The transparent cap enhances papilla visualization and stability, facilitating deep biliary cannulation by maintaining the catheter tip in the optimal position for the common bile duct access. Cannulation can then be achieved either by directly pushing the catheter or by suctioning the papilla into the cap for passive advancement.[14] Additionally, in a recent single-center study comparing cap-assisted gastroscopes and duodenoscopes, both had similar success and complication rates on patients with Billroth II anatomy, though duodenoscopes had shorter cannulation times, potentially reducing pancreatitis risk.[10]

According to the European Society of Gastrointestinal Endoscopy (ESGE) guidelines from 2016, experienced endoscopists prefer side-viewing endoscopes due to the presence of an elevator and a large working channel, which helps in better papilla identification.[15] However, in Billroth II anatomy, limited visibility with the side-viewing scope makes forward-viewing endoscopes relatively easier and safer to use.[12] A meta-analysis in 2018 reported higher success rates with forward-viewing endoscopy (with or without cap) compared with side-viewing scopes in Billroth II anatomy (90.3 vs. 86.8%, cannulation up to 93.7% with cap), making it a safer first option for less experienced endoscopists.[16]

Traditional ERCP using a standard duodenoscope is technically challenging in RYGB patients due to the need to navigate through lengthy Roux limbs (80–150 cm) to access the papilla.[17] Various attempts have been recorded with pediatric colonoscopes dating back to as early as 1988.[18] However, even combined techniques have also shown only a 33 to 67% success rate despite multiple attempts, with the lowest being with a conventional duodenoscope.[17]

In the Whipple procedure (pancreaticoduodenectomy), ERCP is also faced with significant challenges, such as inability to access the affected limb and identification of the ductal anastomosis (choledochojejunostomy or pancreaticojejunostomy). Despite using gastroscopes or enteroscopes, afferent limb intubation remained difficult. Overall technical success rate ranged from 51 to 62% across various studies, with complication rates at 2%.[19]

These limitations prompted the development of DAE and alternate access methods discussed below.


Device-Assisted Enteroscopy-ERCP

Enteroscopes were originally utilized for the diagnosis and management of small bowel disorders.[17] However, a case series by Aabakken et al in 2006 demonstrated that double-balloon enteroscopy (DBE) is a safe and feasible option for achieving endoscopic access and biliary cannulation in patients with Roux-en-Y anatomy.[20] Since then, different balloon-assisted or rotational overtube-assisted techniques, such as DBE, single-balloon enteroscopy (SBE), and spiral enteroscopy (SE), have been increasingly utilized to perform ERCP, particularly in patients with RYGB.[17] A schematic illustration is summarized in [Fig. 2]. While traditional long enteroscopes (200 cm) with smaller channels (2.8 mm) limited the use of standard ERCP tools, the development of short DBE and SBE scopes (155 cm) with wider 3.2 mm channels has helped overcome these limitations.[9]

Zoom
Fig. 2 Schematic illustration of device-assisted enteroscopy (DAE) techniques in patients with Roux-en-Y gastric bypass (RYGB) anatomy. The image highlights the endoscopic approaches used to navigate through the gastric pouch, excluded stomach, jejunal Roux limb, and biliopancreatic limb to access the biliary system. These DAE techniques facilitate diagnostic and therapeutic ERCP in patients with surgically altered upper gastrointestinal anatomy. From left to right: (A) double-balloon enteroscopy (DBE), (B) single-balloon enteroscopy (SBE), and (C) spiral enteroscopy.

Among DAE systems, DBE uses balloons on both the endoscope and the overtube, while SBE has a single balloon on the overtube, simplifying setup and reducing procedure time. DBE advances through a push-and-pull mechanism using alternating balloon inflation, whereas SBE relies on tip angulation and bowel wall suction (“hook-and-suck”) for scope stability. SE uses a rotating overtube to pleat the bowel onto the endoscope, allowing deep advancement with a clockwise rotation combined with forward pressure. These techniques offer deeper small bowel access, expanding therapeutic ERCP options in patients with complex postsurgical anatomy.[21]

In Type I reconstructions, DAE-ERCP is hardly ever required.[22] In Type II anatomy, the success rate of DAE-ERCP is the highest in Billroth II anatomy, followed by pancreaticoduodenectomy and Roux-en-Y hepaticojejunostomy, with the lowest success rates in patients with RYGB. Cannulation rates appeared to be equivalent in patients with both native papilla and biliary-enteric or pancreaticoenteric anastomosis. This was mostly dependent on limb length.[23]

While DAE achieves technical success rates of 95 to 100% in Billroth II and overcomes the anatomical challenges of the afferent limb, it remains technically demanding and limited by a lack of en face papillary views.[24] A meta-analysis by Skinner et al reported a 70% success rate for device-assisted ERCP (SBE, DBE, spiral) in RYGB patients, with no significant differences between enteroscope types or access routes.[23] Similar findings by De Koning and Moreels showed lower success with long-limb RYGB and comparable adverse event rates for DBE (10%) and SBE (8%), mostly managed conservatively.[25] In Whipple anatomy, SBE has shown technical success rates of up to 90% without serious adverse events.[26] ERCP with DBE is limited by its small channel size, allowing only 7-Fr stents and fewer accessory options. While the overtube helps maintain scope position and aids cannulation by allowing torque, the endoscopic view remains oblique rather than en face, even in optimal conditions. Similar drawbacks are seen in SBE.[27] Although insertion success rates were similar for both long and short DBEs, Katanuma and Isayama noted that short DBEs were more operator-friendly due to enhanced control, increased insertion force, and improved compatibility with therapeutic devices.[28] The major published outcomes of DAE in SAA are summarized in [Tables 1] to [3], stratified by double-balloon, single-balloon, and SE, respectively.

Table 1

Summary of major studies on double-balloon enteroscopy (DBE) in surgically altered anatomy

First author (year)

Study type

Anatomy

Endoscopy success rate

ERCP Success rate

Adverse events

AGREE classification

Long scope DBE

Aabakken (2007)[20]

Retrospective

Variable

93% (14/15)

80% (12/15)

0%

Mild/Moderate: No major AEs reported

Emmett (2007)[95]

Retrospective

Variable

80% (4/5)

80% (4/5)

0%

Mild/Moderate: No major AEs reported

Maaser (2008)[96]

Retrospective

Variable

73% (8/11)

NR

0%

Mild/Moderate: No AEs reported

Mönkemüller (2009)[97]

Retrospective

Variable

94.1% (16/17)

NR

5.8% (1/17); perforation necessitating surgery (1)

Severe: 1 perforation requiring surgery (Grade 3)

Moreels (2009)[98]

Retrospective

Variable

86.70%

NR

6.6% (1/15); perforation requiring surgery (1)

Severe: 1 perforation requiring surgery (Grade 3)

Parlak (2011)[99]

Retrospective

RYHJ

92.90%

NR

4.8% (1/21); retroperitoneal air

Mild: Retroperitoneal air (Grade 1–2)

Raithel (2011)[100]

Retrospective

Variable

74%

NR

5.8% (5/86); perforation necessitating surgery (2); bleeding(1); pancreatitis(2)

Mild/Moderate: Perforation requiring surgery (Grade 3), bleeding (Grade 2), pancreatitis (Grade 2)

Liu (2017)[101]

Retrospective

RYGB

75.6% (65/86)

NR

2/86 procedures (2%)

Mild: 2/86 procedures (2%) AE, likely Grade 1–2

Kashani (2018)[102]

Retrospective

RYGB

93.8% (121/129)

NR

Overall adverse event rates were 11% (12/109) and 5% (1/20) for operators A and B

Mild/Moderate: 11% (12/109) AE Operator A; 5% (1/20) Operator B

Short scope DBE

Shimatani (2009)[103]

Retrospective

Variable

97% (100/103)

NR

5% (5/103); Perforation (5) with 1 requiring surgery

Mild/Severe: 5% (5/103); 1 required surgery (Grade 3)

Tsujino (2010)[104]

Retrospective

Variable

100%

(6/6)

NR

33% (2/6); Cholangitis (1); retroperitoneal air (2)

Moderate/Severe: 33% (2/6); cholangitis (Grade 2), retroperitoneal air (Grade 1–2

Cho (2011)[105]

Retrospective

Variable

86.2% (25/29)

NR

0% (0/29)

Mild: 0% AE

Itoi (2010)[106]

Retrospective

Variable

100% (9/9)

NR

0%

Mild: 0% AE

Osoegawa (2012)[107]

Retrospective

Variable

96% (47/49)

NR

2.1% (1/47); Perforation requiring surgery (1)

Moderate/Severe: 2.1% (1/47); perforation requiring surgery (Grade 3)

Park (2013)[108]

Retrospective

Variable

80% (8/10)

NR

0%

Mild: 0% AE

Siddiqui (2013)[109]

Retrospective

Variable

89% (71/79)

NR

5% (4/79); Pancreatitis (3); bleeding (1)

Mild/Moderate: 5% (4/79); pancreatitis (Grade 2), bleeding (Grade 2)

Tsutsumi (2015)[110]

Retrospective

Variable

98.6% (71/72)

NR

3% with cholangitis (conservative management)

Mild/Moderate: 3% cholangitis, conservative (Grade 1–2

Cheng (2015)[111]

Retrospective

Bilroth II

94.8% (73/77)

NR

6.50%

Mild/Moderate: 6.5% AE

Shimatani (2016)[112]

Prospective

Variable

97.7% (304/311)

NR

10.6% (33 patients)

Mild/Moderate: 10.6% AE

Uchida (2020)[113]

Retrospective

Variable

94.3% (759/805)

NR

5.50%

Mild/Moderate: 5.5% AE

Ishihara (2021)[114]

Retrospective

Variable

92%

NR

6.80%

Mild/Moderate: 6.8% AE

Notes: Endoscopy success rate refers to technical success (successful advancement to the papilla or biliary anastomosis). ERCP success rate refers to therapeutic success (successful cannulation and/or completion of intended intervention). Adverse events are stratified by severity according to the AGREE classification.


Table 2

Summary of major studies on single-balloon enteroscopy (SBE) in surgically altered anatomy

First author (year)

Study type

Anatomy

Endoscopy success rate

ERCP success rate

Adverse events

AGREE classification

Single-balloon enteroscopy

Neumann (2009)[115]

Retrospective

Variable

77%

(10/13)

NR

0%

0%

Itoi (2010)[116]

Retrospective

Variable

92.3% (12/13)

NR

0%

0%

Wang (2010)[117]

Retrospective

Variable

81.3% (13/16)

NR

12.5% (2/16); pancreatitis (2)

0%

Itoi (2011)[106]

Retrospective

Variable

100% (15/15)

NR

0%

0%

Saleem (2010)[118]

Retrospective

Variable

75% (42/56)

NR

0%

0%

Kianicka (2013)[119]

Retrospective

Variable

100% (15/15)

NR

0%

0%

Azeem (2013)[120]

Retrospective

Variable

91.4% (53/58)

NR

0%

0%

Tomizawa (2014)[121]

Retrospective

Variable

68% (15/22)

NR

0%

0%

Notes: Endoscopy success rate refers to technical success (successful advancement to the papilla or biliary anastomosis). ERCP success rate refers to therapeutic success (successful cannulation and/or completion of intended intervention). Adverse events are stratified by severity according to the AGREE classification.


Table 3

Summary of major studies on SE in surgically altered anatomy

First author (year)

Study type

Anatomy

Endoscopy success rate

ERCP success rate

Adverse events

AGREE classification

Spiral enteroscopy

Wagh (2012)[122]

Prospective

Variable

77% (10/13)

NR

0%

0%

Lennon (2012)[123]

Retrospective

RYGB

28% (7/25)

NR

0%

0%

Shah (2013)[124]

Retrospective

RYGB

62% (16/26)

NR

Overall 12% including DBE and SBE; perforation (2), abdominal pain (3), throat pain (4), pancreatitis (5), bleeding (1), death (1)

0%

Zouhairi (2015)[125]

Retrospective

RYGB

64.3% (27/42)

NR

23.8% admissions, including 7.1% post-ERCP pancreatitis

0%

Ali (2018)[31]

Retrospective

RYGB ± others

86% (27/31)

NR

0%

0%

Al-Toma (2022)[126]

Prospective

Variable (20% altered anatomy)

70.3% (total enteroscopy)

NR

15.9% minor, 0% major

0%

Schneider (2023)[127]

Retrospective

RYGB + Bilroth II

72.2% (26/36)

NR

2.8% major (delayed post-sphincterotomy bleeding)

0%

SAMISEN-B (2024)[128]

Prospective

RYGB + Billroth II

54% (48/88)

NR

14% overall, 7% serious (1 MSE-related perforation)

0%

Nennstiel (2025)[129]

Retrospective

RYGB

73.1% (19/26)

NR

11.5% overall (1 enteroscopy-related laceration, 1 post-ERCP pancreatitis, 1 anesthesia complication)

0%

Abbreviations: DBE, double-balloon enteroscopy; ERCP, endoscopic retrograde cholangiopancreatography; NR, not reported; SBE, single-balloon enteroscopy; SE, spiral enteroscopy.


Notes: Endoscopy success rate refers to technical success (successful advancement to the papilla or biliary anastomosis). ERCP success rate refers to therapeutic success (successful cannulation and/or completion of intended intervention). Adverse events are stratified by severity according to the AGREE classification.



Elevator Limitation in DAE Scopes

Several studies have highlighted that a major technical limitation of DAE systems, including SBE and DBE, is the absence of a distal elevator mechanism. Unlike conventional side-viewing duodenoscopes, DAE scopes do not provide elevator control at the instrument tip, which restricts the maneuverability and precise orientation of accessories within the papilla or bile duct. This limitation poses significant challenges during selective biliary cannulation, sphincterotomy, and stent deployment, particularly in patients with SAA.[23] [29] The lack of an elevator consequently contributes to the lower therapeutic success rates and longer procedural times observed in DAE-ERCP compared with standard duodenoscope-assisted ERCP.[30] [31]


Laparoscopy-Assisted ERCP

First described in 2002, LA-ERCP is a hybrid approach that employs minimally invasive surgery to allow passage of a standard duodenoscope through the stomach rather than transorally.[32] This procedure involves creating a gastrostomy through which a standard duodenoscope can be advanced to access the duodenum via the remnant stomach.[33]

Particularly effective in RYGB patients, it allows direct inspection of the abdominal cavity, facilitates the use of conventional ERCP tools, and avoids the delays associated with traditional gastrostomy-based approaches. When performed in experienced centers, it offers high success rates with same-day or next-day discharge in most cases.[27]

LA-ERCP has shown superior technical success in managing pancreaticobiliary diseases in RYGB patients, with rates exceeding 95%, compared with 60 to 70% with DAE techniques.[34] A recent meta-analysis demonstrated that both technical and clinical success rates were significantly higher with LA-ERCP compared with DAE-ERCP. Interestingly, it also reported a lower adverse event rate with LA-ERCP, contradicting earlier studies that had favored EA-ERCP for its safety profile.[35]

In contrast, the study by Gkolfakis et al reported a higher incidence of adverse events following interventional procedures overall, suggesting that the increased risk was more related to the access route (LA or EUS-guided) than to ERCP itself. LA-ERCP is associated with a greater risk of intra-abdominal infections, abscess formation, perforation, and hematomas.[36] The fact that it requires laparoscopy makes it more invasive than enteroscopy-assisted techniques. Supine positioning, limited access due to drapes, and poorly placed gastrostomies, especially near the pylorus, can hinder duodenoscope advancement. Optimal outcomes depend on precise surgical planning, with lateral gastrostomy placement along the greater curvature facilitating smoother scope passage.[27]

With these contradictions, there has been a growing shift toward less invasive, endoscopy-only approaches such as EUS-BD and EUS-directed transgastric ERCP (EDGE) as discussed later.


EUS-Guided Biliary Drainage

EUS-BD has been extensively reported since its first description by Giovannini et al in 2001.[37] In the last two decades, it has become one of the main alternatives for patients with unsuccessful ERCP from various reasons, or inaccessible papilla because of duodenal strictures, or surgically modified anatomy.[38] In a retrospective comparative study by Hakuta et al, EUS-BD demonstrated a higher technical success rate compared with DAE-ERCP, with no significant differences in clinical outcomes or adverse events. The findings suggest that EUS-BD may be a particularly effective option in patients with an intact papilla, where DAE-ERCP tends to have lower technical success.[39]

EUS-BD techniques create a new conduit from the biliary system to the gastrointestinal tract under EUS guidance, avoiding the need to reach the papilla. Broadly, EUS-BD can be achieved via three approaches: (1) EUS-guided rendezvous, (2) EUS-transmural drainage, and (3) EUS-guided antegrade interventions,[9] as summarized in [Fig. 3].

Zoom
Fig. 3 Different options when considering EUS-guided biliary drainage.

EUS-rendezvous (EUS-RV): This procedure involves EUS-guided bile duct puncture and advancement of a guidewire into the duct, which is then used to facilitate a second attempt at biliary cannulation, thus serving as a salvage technique in cases where standard deep cannulation has failed.[40] EUS-RV can be divided into an intrahepatic biliary duct (IHBD) approach and an extrahepatic biliary duct (EHBD) approach.[41] A recent meta-analysis comparing EUS-guided rendezvous (EUS-RV) and percutaneous transhepatic biliary (PTB)-RV showed comparable technical success rates (88.7% versus 94.1%) and overall adverse event rates (9.8% versus 13.4%), suggesting that EUS-RV is an effective salvage option after failed cannulation, but with careful technique.[42]

EUS-transmural drainage: This technique involves creating a direct fistulous tract between the biliary system and the gastrointestinal lumen to facilitate drainage via stent placement. The tract is typically established between the extrahepatic common bile duct and the duodenum (EUS-choledochoduodenostomy [EUS-CDS]) or between the left intrahepatic bile duct and the stomach (EUS-hepaticogastrostomy [EUS-HGS]). Recently, a connection between the biliary tree and the Roux limb (EUS-hepaticojejunostomy [EUS-HJS]) has gained popularity.[43] A recent multicenter study on EUS-HJS in post-gastrectomy patients showed 100% technical and 80% clinical success, with a 33% adverse event rate, comparable to EUS-HGS. While it offers advantages over percutaneous transhepatic biliary drainage (PTBD)—such as internal drainage and easier reintervention—it remains technically demanding and requires further evaluation in larger studies.[38]

EUS-guided antegrade intervention (EUS-AI): It is a minimally invasive alternative in which the echoendoscope is used to create a temporary fistula between the intestine and the bile duct, allowing antegrade traversal of a stricture or papilla to place a stent or dilate the obstruction from the proximal side.[44]

All the above procedures can be employed in patients with native gastrointestinal anatomy when ERCP fails or when anatomical challenges such as ampullary distortion, diverticula, or the presence of duodenal stents hinder conventional access.[43] In Type I anatomies, where the papilla is endoscopically reachable, EUS-RV, EUS-AI, and EUS-CDS can be considered as an alternative in cases of failed ERCP.[9] [41] EUS-RV may be feasible in some type II cases; however, when the papilla is inaccessible, alternative approaches such as EUS-guided antegrade stenting or transmural techniques like EUS-HGS or EUS-HJS are required.[9] [Table 4] summarizes the major published studies evaluating EUS-BD in patients with SAA.

Table 4

Summary of major studies on EUS-guided biliary drainage in surgically altered anatomy

First author (year)

Study type

No. of patients

Anatomy

Endoscopy success rate (technical and clinical)

ERCP success rate

Adverse events

AGREE classification

Weilert (2011)[130]

Antegrade approach

6

RY gastric bypass

TS = 67%; CS = NA

NR

Liver hematoma—1 case

Moderate

Iwashita (2013)[131]

Antegrade approach

101

RY gastrojejunostomy, Whipple's

TS = 100%; CS = NA

NR

Mild pancreatitis—2

Mild

Itoi (2014)[132]

Antegrade approach

28

RY, gastric bypass, Billroth reconstruction

TS = 60%; CS = NA

NR

Nil

Nil

Khashab (2016)[52]

Antegrade approach

49

RY reconstruction, RYGB, Whipple, B-II

TS = 98%; CS = 88%

NR

20%

Moderate

Miranda-García (2016)[133]

Antegrade approach

7

Biliary enteric anastomosis (details N/A)

TS = 57%; CA = 100%

NR

70% bleeding, stent migration

Severe

Iwashita (2016)[44]

Antegrade approach

29

GR with RY-19; GR with BII-3;

GR with jejunal interposition-2;

PD-4; BDR with HJ-1

79%

NR

17% bile peritonitis, cholecystitis, elevated CRP

Moderate

James (2018)[134]

Antegrade approach

29

RYGB, RY, B-II reconstruction, Whipple

TS = 95%; CS = 95%

NR

15% abdominal pain, mild pancreatitis, mild cholangitis

Mild

Hosmer (2018)[135]

Antegrade approach

9

RYGB, RY

TS = 100%; CS = NA

NR

11% cholangitis

Mild

Mukai (2019)[136]

Antegrade approach

48

RY, RYGB, Whipple, B-II

TS = 91.9%; CS = 91.9%

NR

8.1% Biliary peritonitis

Moderate

Huang (2020)[137]

Transmural drainage; EUV RV-8; EUS-HG = 14; EUS-CD = 11

60

Billroth I, Billroth II, RYGB, RYHJ Roux-en-Y choledochojejunostomy

TS = 93.3%; CS = 84.9%

NR

9.09% hemorrhage, cholangitis

Moderate

Minaga (2020)[138]

Transmural stenting—24; Antegrade stenting—2; combination of transmural and antegrade—14

40

Gastrectomy with RY, Billroth-II, pancreaticoduodenectomy, RYHJ

TS = 100%; CSB = 95%

NR

15% bile leak, biliary peritonitis, pneumoperitoneum

Moderate to severe

Abbreviations: CS, clinical success ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound; NR, not reported; TS, technical success.


Endoscopy success rate refers to technical success (successful advancement to the papilla or biliary anastomosis). ERCP success rate refers to therapeutic success (successful cannulation and/or completion of intended intervention). Adverse events are stratified by severity according to the AGREE classification.


Some studies were conducted to see the combined effectiveness of EUS-AI with a self-expandable metal stent (SEMS) and EUS-HGS (or EUS-HJS). In 2017, Ogura et al conducted a multicenter pilot study on EUS-HJS with antegrade stenting for malignant biliary obstruction, achieving an 85.7% technical success rate. Adverse events occurred in 10.2% of patients, mainly hyperamylasemia and one case of bleeding. Stent dysfunction in seven cases was managed with cleaning or replacement.[45] In 2019, Yang et al introduced EUS-directed transenteric ERCP (EDEE) using a lumen-apposing metal stent (LAMS) to access the biliary tree in altered, non-RYGB anatomy. In this study of 18 patients, fistulas were created in all, with 94% success and only two mild adverse events, which were medically managed.[46]

In the meta-analysis by Facciorusso et al, PTBD was found to be similar to EUS-HGS and EUS-CDS in terms of technical and clinical success, but a trend toward higher adverse event rates was noted with PTBD.[47] Similarly, another study conducted by Iwashita et al showed similar success rates between EUS-AI and PTBD, with PTBD showing greater adverse events.[48] A recent meta-analysis of eight studies comparing EUS-BD and ERCP/PTBD demonstrated that EUS BD outperformed ERCP-BD and PTBD in reducing stent dysfunction, postprocedural pancreatitis, and tumor ingrowth or overgrowth.[49] Importantly, EUS-BD provides internal drainage, an advantage over PTBD in terms of patient comfort and convenience (no external catheter). This has led both the European and American endoscopy societies to endorse EUS-BD as an alternative to PTBD after failed ERCP, in centers with appropriate expertise.[50]

Complications associated with EUS-BD include bile leakage into the peritoneum, peritonitis, pneumoperitoneum, bleeding, and stent misdeployment. A systematic review of EUS-BD documented bile leak in ∼2.2% and infection/cholangitis in ∼1% as the most common early AE.[51] Khashab et al compared EUS-guided biliary interventions with enteroscopy-assisted ERCP in 98 patients with SAA, finding higher clinical success (88 vs. 59.1%) and shorter procedure times with EUS, but a higher rate of adverse events (20 vs. 4%).[52]

In pooled data, overall EUS-BD adverse event rates around 15 to 20% are reported, though most are manageable with conservative measures or endoscopic/radiologic intervention. Recent innovations aim to reduce these risks, like dedicated EUS biliary stents with anti-migratory flaps and the increasing use of LAMS for a secure tract.[9] Despite these encouraging results, the procedure's technical complexity necessitates expert-level proficiency in EUS-guided interventions and careful patient selection through multidisciplinary assessment.[53]


Distinction between Motorized and Manual Spiral Enteroscopy Studies

SE techniques can be broadly divided into manual SE and motorized spiral enteroscopy (MSE), which differ significantly in design, efficiency, and clinical outcomes. Manual SE employs a manually rotated spiral overtube to advance the enteroscope by pleating the small bowel. Early studies using the manual spiral system reported technical success rates of 65 to 85%, therapeutic success of 60 to 75%, and adverse event rates of approximately 5 to 10% in Roux-en-Y anatomy.[54] [55] [56] However, manual SE was physically demanding, had a steep learning curve, and was limited by overtube instability.

In contrast, MSE represents a major technological advancement, incorporating a motor-driven spiral segment integrated into the endoscope that allows controlled rotation via a foot pedal. More recent studies of MSE, including a prospective single-center analysis, a systematic review and meta-analysis, and the multicenter SAMISEN-B registry, have demonstrated substantially improved performance, with technical success rates of 90 to 100%, therapeutic success of 80 to 95%, and a shorter learning curve of approximately 10 to 15 cases.[57] [58] [59] [60]

Adverse events remain comparable to manual SE (6–12%), primarily minor mucosal trauma or transient bleeding ([Table 5]).

Table 5

Comparison of manual and motorized spiral enteroscopy in surgically altered anatomy

Parameter

Manual spiral enteroscopy

Motorized spiral enteroscopy

Technical success[54] [55] [56] [57] [58]

65–85%

90–100%

Therapeutic success[59] [60]

60–75%

80–95%

Learning curve[54] [57]

Steep; 25–30 cases for proficiency

Shorter; 10–15 cases

Procedure time[58]

Longer; manual advancement

20–30% shorter due to controlled motor drive

Adverse events[54] [59]

5–10%; mucosal trauma, minor bleeding

6–12%; mostly minor, rarely serious

EDGE Procedure

EDGE, first described by Kedia et al in 2013, involved a two-stage approach using an EUS-guided gastrostomy followed by antegrade ERCP with a side-viewing duodenoscope to reach the papilla. This procedure involved the use of a PEG tube followed by a fully covered self-expanding metal stent (FCSEMS). While EDGE offers technical success rates >95%, comparable to ERCP in standard anatomy and superior to DAE-ERCP (60–70%), it is limited by its classical two-stage nature, making it less suitable in emergent scenarios like acute cholangitis.[61]

The advent of tissue anchoring techniques such as endoscopic suturing, however, has advanced the EDGE technique to a single-stage version. In 2014, Kedia et al advanced the EDGE technique by introducing a single-stage version (SS-EDGE) by using LAMS. This upgraded technique involves creating a gastro-gastric (G–G) or jejuno-gastric (J–G) fistula with the excluded stomach using an EUS-guided LAMS placement, followed by anchoring of the stent using dedicated clips made for stent anchoring, such as Stent-fix (Ovesco, Germany) or using endoscopic suturing (Boston Scientific, Massachusetts, United States).[62]

In a large multicenter study by Runge et al involving 178 patients (mean age: 58 years, 79% women), the EDGE procedure achieved a 98% technical success rate with an average procedure time of 92 minutes. Periprocedural adverse events occurred in 15.7% of patients, including 2.2% with severe events managed laparoscopically. Among those who underwent follow-up testing, persistent fistula was identified in 10%, with successful endoscopic closure achieved in all treated cases.[63]

In a recent meta-analysis of 16 studies (470 patients), EDGE demonstrated high technical (96%) and clinical (91%) success rates with a 17% adverse event rate, comparable to LA-ERCP but superior to E-ERCP in efficacy. EDGE also offered lower costs, shorter procedure times, and hospital stays.[64] Also, a 2018 multicenter study found EDGE had 100% success versus 60% for enteroscopy (p < 0.001), with shorter procedure time (50 vs. 91 minutes) and shorter median hospitalization (1 vs. 10.5 days).[65]

The primary concern based on the above studies has been stent dislodgment or leakage leading to peritonitis, and the potential for a persistent fistula that could enable to regain weight in bariatric patients. To counter this, some protocols use an initial slim endoscope or perform ERCP in a second session.[66] Anchoring techniques have also been employed: suturing the LAMS in place, or immediately exchanging the LAMS for a fully covered esophageal stent or a double-pigtail after ERCP to maintain the tract.[17] Another study by Hsueh et al attempted to use 20-mm LAMS to reduce stent migration.[67]


Risk of LAMS Migration with Immediate Balloon Dilation

Immediate balloon dilation of a newly deployed LAMS at the index EDGE session has been repeatedly implicated as a major risk factor for intraprocedural stent dislodgement and early migration. The proposed mechanism is mechanical dilation and passage of a duodenoscope through an immature fistulous tract can exert shear forces on the LAMS flanges before adequate tissue apposition and tract maturation have occurred, leading to flange separation or proximal displacement. Several clinical series and multicenter reports therefore reported higher rates of LAMS dislodgement with single-session (index) dilation/ERCP and consequently adopted alternative strategies (delayed ERCP or active fixation) to improve safety.[68] [69] [70] Contemporary guidelines and technical reviews now recommend avoiding routine balloon dilation and same-session duodenoscope passage when possible, instead delaying therapeutic ERCP for a short interval (commonly 7–14 days) to allow tract maturation; when same-session therapy is unavoidable, operators should consider larger-diameter LAMS, and use adjunctive anchoring/fixation techniques (endoscopic suturing, through-the-scope clips or double-pigtail stents) to mitigate migration risk.[71] [72] In short, real-world practice has shifted toward a “safety-first” approach—avoid immediate aggressive dilation at the index session when feasible, delay ERCP to allow tract healing, or employ reliable anchoring strategies if immediate therapy is clinically necessary.

Another key concern is the development of a persistent fistula, defined as a gastro-gastric or jejuno-gastric fistula that fails to close either by primary or secondary intention. Persistent fistulas are theoretically worrisome because they may functionally reverse the bypass and lead to weight regain, while also necessitating additional endoscopic interventions for closure.[73] This has raised an ongoing debate over whether the fistula should be actively closed at the time of ERCP (primary closure) or allowed to heal spontaneously (secondary intention). Comparative analyses have shown no clear advantage of primary closure over secondary intention. Ghandour et al found closure did not reduce fistula formation, which was instead predicted by longer stent dwell times.[74] [75] Similarly, Bertran-Rodriguez et al reported no difference in fistula or weight outcomes between closure and no closure.[67]

To minimize fistula-related issues, Wang et al suggested the GATE strategy (gastric access temporary for endoscopy). In GATE, after completing ERCP, the LAMS is promptly exchanged for a double-pigtail stent to maintain drainage but encourage fistula closure once removed. In this case series of 10 GATE patients, all had confirmed fistula closure, and no significant weight change occurred.[76]

In summary, EDGE has become an attractive first-line option for RYGB patients at centers with advanced endosonography expertise. It achieves near-surgical success rates with a single endoscopic team. The 2024 ASGE guideline explicitly recommends considering EDGE (also termed EUS-directed transgastric ERCP) over laparoscopic or enteroscopy-assisted methods in RYGB anatomy, given its high efficacy when performed in experienced centers.[50] The main caveats are ensuring appropriate patient selection (those who can tolerate a transmural fistula) and having robust protocols to manage the fistula (removal and closure) after the ERCP is done. With growing experience, EDGE has proven safe and effective, solidifying its role in the algorithm for bariatric anatomy and biliary access.

Procedures such as DAE-ERCP, advanced EUS-BD, and EDGE are technically demanding and exhibit a steep learning curve. Outcomes are significantly influenced by the experience of the operator and the expertise of the center. For instance, ERCP success rates are notably higher in centers with greater case volumes and experienced endoscopist.[77] Similarly, EUS-BD procedures demonstrate improved efficiency and reduced complication rates as the operator gains experience, with a learning plateau typically observed after ∼32 cases.[78] These factors underscore the importance of considering operator and institutional experience when evaluating reported success rates.


Percutaneous Transhepatic Biliary Drainage

Even with the advent of advanced endoscopic techniques, percutaneous and surgical interventions remain important in the SAA biliary drainage toolkit—particularly in urgent settings or when endoscopic methods are unavailable. PTBD has long been the fallback for failed ERCP. In this procedure, an interventional radiologist inserts a needle through the liver into an intrahepatic bile duct under fluoroscopy or combined imaging and fluoroscopic guidance, typically placing a catheter that drains bile to an external bag.[79]

A multicenter retrospective study of 630 patients (411 endoscopic, 219 PTBD) reported overall endoscopic success of 57% (highest in Billroth-II: 70.5%; lowest in Roux-en-Y: 49.5%). PTBD achieved a higher technical success rate of 91% but carried more complications (11.6 vs. 7.1%), with duodenoscopes in Billroth-II reconstructions showing a higher risk. Cumulative success after repeat endoscopic attempts was only 39%. While PTBD remains an effective salvage option, its higher morbidity, repeat intervention requirements, and impact on quality of life limit its role to a salvage option. In contrast, endoscopic techniques, despite lower success, are preferred due to lower morbidity, especially in well-selected patients.[3]

PTBD is often preferred in hemodynamically unstable patients, those unfit for general anesthesia, or when malignancy is suspected or EUS-BD is unavailable. Traditionally, the second-line option after failed ERCP, it offers high success rates but carries increased risks of bleeding, dislodgement, and peritonitis.[50] Even when compared with newer techniques, PTBD demonstrates less favorable outcomes. While Pleasant et al reported comparable success to LA-ERCP, PTBD was linked to higher complications and repeat interventions.[80] Another study showed EUS-BD to be more cost-effective compared with PTBD.[81]

For these reasons, ASGE 2024 guidelines advocated for EUS-BD over PTBD after a failed ERCP, provided appropriate expertise is available.[50] PTBD still has a crucial role in emergencies like severe cholangitis when endoscopic options are not immediately at hand.

Some studies have looked into the hybrid approaches for PTBD, such as the rendezvous technique, which involves both an interventional radiologist (IR) and an endoscopist. In this, IR advances a guidewire via PTBD into the duodenum, allowing the endoscopist to retrieve it and place a stent across the papilla or anastomosis. This improves technical success (80–90%) and significantly lowers complication rates compared with PTBD alone. Completing both steps in a single session also reduces catheter-related and septic complications and shortens hospital stay.[82]

Another hybrid approach is the PATENT technique (percutaneous-assisted transprosthetic endoscopic therapy), pioneered by Baron and Song.[83] In this, a percutaneous gastrostomy is created endoscopically or radiologically into the excluded stomach of an RYGB patient. Through this tract, a fully covered metal stent is placed, forming a stable path into the remnant stomach, and then a duodenoscope is inserted through the stent for ERCP. Early PATENT reports showed feasibility but also noted issues like stent migration and stoma infection. With the advent of LAMS, the EUS-guided version of PATENT (i.e., EDGE) has largely replaced it, being simpler and entirely endoscopic.[17]


Cost-effectiveness and Resource Considerations

While EDGE offers higher technical and clinical success rates compared with DAE–ERCP and PTBD, its widespread adoption is limited by the need for specialized EUS expertise, availability of LAMS, and endoscopy infrastructure. In low-resource settings, particularly in parts of Asia and other developing regions, PTBD remains a more feasible option due to lower equipment costs and broader procedural availability, despite its higher patient discomfort and risk of external drains.[84] Economic analyses suggest that EDGE may be cost-effective in high-volume tertiary centers with trained personnel, but the upfront investment and resource intensity restrict its applicability in many resource-limited hospitals.[85]


Hybrid, Novel, and Experimental Techniques

The field of therapeutic endoscopy is continuously evolving, and several novel technologies on the horizon may further improve biliary access in altered anatomy.

3D-guided technologies: To enhance EUS-BD and surgical accuracy, advanced imaging is being incorporated, such as using CT/MRI during the procedure to better identify the site for hepaticogastrostomy.[86] Zhang et al explored the feasibility of real-time continuous image-guided ERCP and concluded it to be an effective approach with reduced X-ray exposure and contrast agents.[87] Such technology may reduce the time and risk of LA-ERCP by mapping adhesions and target structures before making incisions.

Artificial intelligence (AI)-assisted navigation: AI is being explored to assist endoscopists in recognizing postsurgical anatomy and locating the correct limb or anastomosis. Kim et al developed an AI-assisted system using convolutional neural networks to help endoscopists identify the ampulla of Vater (AOV) and assess cannulation difficulty during ERCP. The AI model achieved high accuracy, with a 91.4% success rate in ampulla detection and performed comparably to expert endoscopists. It also showed promising results in predicting difficult cannulation cases, suggesting that AI could enhance procedural efficiency and safety in complex endoscopic settings.[88]

Biodegradable stents: A persistent issue in managing benign biliary strictures (such as biliary-enteric anastomotic strictures) is the need for multiple interventions to place and remove stents. Biodegradable biliary stents offer a promising solution. These stents, made of polymers like polydioxanone, maintain duct patency initially but then gradually dissolve, obviating the need for endoscopic removal. Early reports in patients with SAA have been encouraging. In a series of seven patients with benign biliary strictures and altered anatomy, biodegradable stents were deployed via DBE with 100% technical success; none required a second ERCP for stent removal.[89]

Magnetic compression anastomosis: It is a novel minimally invasive technique for restoring continuity across completely obstructed ducts or anastomoses, especially in benign biliary strictures refractory to standard approaches. The method involves placing two magnets on either side of the occlusion—typically via PTBD into the proximal bile duct and endoscopically into the bowel, which gradually forms a fistula through ischemic necrosis of the intervening tissue. Clinical success rates of up to 87.5% have been reported, with low recurrence and minimal complications, making it a promising option in complex cases.[90] [91]

In summary, the coming years are likely to bring multiple innovations that make biliary drainage in SAA safer, easier, and more universally available. Robotic enteroscopy and AI may help more endoscopists succeed in difficult anatomies. New anastomosis techniques like magnetic compression could offer nonsurgical cures for occluded passages. And improved stents—whether dissolving or medicated—will enhance long-term outcomes. These hybrid and experimental techniques continue the trend of multidisciplinary innovation in this challenging field. [Fig. 4] depicts our proposed algorithm for biliary drainage in SAA based on our review of the currently available techniques.

Zoom
Fig. 4 Proposed algorithm for biliary drainage in surgically altered anatomy (SAA).

Long-Term Outcomes in EDGE and DAE-ERCP

Most published literature on EDGE and DAE–ERCP primarily emphasizes technical and short-term clinical success, such as immediate biliary cannulation or stent placement. However, long-term outcomes, including stent patency, recurrence of biliary strictures, and the need for repeat interventions, are critical for informing clinical decision-making and modality selection. In EDGE, LAMS generally maintain patency in the short term, but follow-up studies report variable rates of stent occlusion and recurrent strictures, particularly if the fistulous tract closes prematurely or tract maturation is incomplete.[92] DAE-ERCP, while effective in altered anatomy, may be limited by restricted accessory maneuverability and higher rates of incomplete drainage or stricture recurrence.[93] [94] In resource-limited settings, PTBD remains an alternative with durable patency, though it carries long-term risks such as infection, external drain complications, and patient discomfort.[84] Collectively, these data suggest that, beyond immediate procedural success, clinicians must consider long-term patency, stricture recurrence, and anticipated reinterventions when choosing between EDGE, DAE-ERCP, and PTBD, particularly in populations with SAA or limited access to specialized endoscopy services.


Conclusion

Biliary drainage in patients with SAA remains a complex challenge that is becoming increasingly relevant in the wake of rising bariatric and oncologic surgical procedures. Traditional ERCP demonstrates high success in Type I anatomies but faces significant limitations in Type II reconstructions due to altered intestinal continuity and anatomical complexity. Device-DAE-ERCP, while effective in some scenarios, remains technically demanding and time-consuming, with variable success rates. The emergence of EUS-BD, including rendezvous, transmural, and antegrade techniques, has offered a minimally invasive and effective alternative, with favorable outcomes compared with percutaneous approaches. In particular, the EDGE procedure has revolutionized management in RYGB patients by facilitating high-success ERCP access. While each approach has merits, tailoring intervention strategies based on the specific surgical anatomy, clinical urgency, and institutional expertise is essential. This review reports the definitions as used in each individual study, while emphasizing that differences in clinical success criteria should be considered when interpreting and comparing outcomes across studies. A multidisciplinary, anatomy-based algorithmic approach involving gastroenterologists, interventional radiologists, and surgeons—combined with growing access to EUS-specific tools—will help optimize outcomes in these complex patients. Continued innovation and prospective comparative studies are needed to standardize techniques and refine practice guidelines in this evolving field.



Conflict of Interest

None.


Address for correspondence

Veeral M. Oza, MD, FASGE
Department of Gastroenterology and Interventional Endoscopy, Bon Secours Mercy Health
317 St. Francis Drive, Suite 310, Greenville, South Carolina
United States   

Publication History

Article published online:
09 January 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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Fig. 1 Surgically altered anatomies. Type I: (A) Billroth I gastrectomy; (B) sleeve gastrectomy. Type II: (C) Roux-en-Y gastric bypass; (D) Billroth 2 gastrectomy; (E) Whipple procedure.
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Fig. 2 Schematic illustration of device-assisted enteroscopy (DAE) techniques in patients with Roux-en-Y gastric bypass (RYGB) anatomy. The image highlights the endoscopic approaches used to navigate through the gastric pouch, excluded stomach, jejunal Roux limb, and biliopancreatic limb to access the biliary system. These DAE techniques facilitate diagnostic and therapeutic ERCP in patients with surgically altered upper gastrointestinal anatomy. From left to right: (A) double-balloon enteroscopy (DBE), (B) single-balloon enteroscopy (SBE), and (C) spiral enteroscopy.
Zoom
Fig. 3 Different options when considering EUS-guided biliary drainage.
Zoom
Fig. 4 Proposed algorithm for biliary drainage in surgically altered anatomy (SAA).