Endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy can be technically challenging, because of three main problems that must be overcome: (1) endoscopically traversing the altered luminal anatomy, (2) cannulating the biliary orifice from an altered position, and (3) performing biliary interventions with available ERCP instruments. This article addresses the most common and most challenging variations in anatomy encountered by a gastroenterologist performing ERCP. It also highlights the innovations and progress that have been made in coping with these anatomic variations, with special attention paid to altered anatomy from bariatric surgery.
Key points
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Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy can be technically challenging because of the difficulty in traversing altered anatomy, cannulation from an altered position, and the lack of standard ERCP accessories for use with longer-length endoscopes.
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For ERCP in most patients with Billroth II anatomy, standard duodenoscopes or gastroscopes (with or without caps) can be used with high success rates.
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For ERCP in patients post Roux-en-Y, longer-length endoscopes or deep enteroscopy techniques are usually necessary. After the biliary orifice is reached, success rates for ERCP are reasonably high. Percutaneous or laparoscopic-assisted access for ERCP may be preferred in patients with long-limb Roux-en-Y gastric bypass.
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An endoscopist’s thorough understanding of the postsurgical anatomy, along with careful preparation and availability of all potentially needed accessories, maximizes the chances of successful ERCP in the patient with surgically altered anatomy.
Introduction
Endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy can be technically challenging, because of three main problems that must be overcome: (1) endoscopically traversing the altered luminal anatomy, (2) cannulating the biliary orifice from an altered position, and (3) performing biliary interventions with available ERCP instruments. This article addresses the most common and most challenging variations in anatomy encountered by a gastroenterologist performing ERCP. It also highlights the innovations and progress that have been made in coping with these anatomic variations, with special attention paid to altered anatomy from bariatric surgery.
Introduction
Endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy can be technically challenging, because of three main problems that must be overcome: (1) endoscopically traversing the altered luminal anatomy, (2) cannulating the biliary orifice from an altered position, and (3) performing biliary interventions with available ERCP instruments. This article addresses the most common and most challenging variations in anatomy encountered by a gastroenterologist performing ERCP. It also highlights the innovations and progress that have been made in coping with these anatomic variations, with special attention paid to altered anatomy from bariatric surgery.
Postsurgical anatomy with conventionally accessible biliary system
Certain types of postsurgical anatomy feature a conventionally accessible biliary system, so ERCP can be performed with a standard duodenoscope and from the usual ERCP position. This offers two important advantages: endoscopist familiarity with standard ERCP techniques, and complete compatibility with standard ERCP tools.
There are several common operations that do not affect access to the patient’s biliary systems: (1) sleeve gastrectomy, in which the greater curvature of the stomach is resected, and the remnant stomach is kept in continuity with the small bowel; (2) laparoscopic adjustable gastric band, in which a band-like device is placed around the stomach immediately beneath the gastroesophageal junction, with the inner portion of the band consisting of a saline-filled silicon balloon that can be inflated or deflated by a subcutaneous access port; and (3) Billroth I distal gastrectomy, in which antrectomy is performed and an end-to-end anastomosis is created between the remnant stomach and the duodenum.
Advancement of the duodenoscope is usually relatively straightforward in these cases. The anatomic variations may be apparent as the stomach is traversed, and there may be variations in endoscope looping and position. However, with the duodenum remaining in continuity, establishing a good position for cannulation of the major papilla is generally not difficult, and the usual ERCP accessories are used for cannulation and therapy.
Postsurgical anatomy with difficult-to-access biliary system
Many surgical procedures create variations in gastrointestinal anatomy, making ERCP challenging or even impossible. The difficulty arises because the gastric outlet is no longer contiguous with the duodenum. Altered anatomy leads to a longer gastrointestinal tract length to traverse to reach the biliary tree and to an unusual cannulation approach from a caudal angle. Duodenoscopes may be of insufficient length to reach the papilla, and ERCP in altered anatomy often requires the use of longer endoscopes, deep enteroscopy techniques, surgically assisted approaches, or additional supporting instruments. Common operations that result in difficult-to-access biliary systems are described next.
Gastrojejunostomy (Including Billroth II)
An anastomosis is created between the stomach and a loop of the jejunum. Typical procedures that use this type of anastomosis include gastrojejunostomy after partial gastrectomy or gastrojejunostomy without gastric resection for treatment of gastric outlet obstruction. The Billroth II distal gastrectomy uses a gastrojejunostomy ( Fig. 1 ). Although this type of operation is performed infrequently in the current era of proton pump inhibitors, it is still encountered by biliary endoscopists, because it was popular in the past for complicated peptic ulcer disease. During the procedure, the distal stomach is resected and an end-to-side gastrojejunostomy is created. From the anastomosis, an afferent limb leads to the more proximal small bowel and duodenum, and an efferent limb leads to the distal small bowel. Approach to the bile duct involves identifying the afferent limb and subsequently advancing the endoscope up the afferent limb and to the papilla.
Roux-en-Y Reconstruction
Roux-en-Y reconstruction adds a level of complexity for the biliary endoscopist. In this operation, the small bowel is divided, usually in the jejunum. The small bowel proximal to the division, which contains the biliary orifice, is anastomosed to a point distal to the location of the division, forming a jejunojejunostomy, and is termed the “biliopancreatic limb.” The portion of small bowel distal to the division is anastomosed to the stomach and is termed the “Roux limb.” Thus, the two upper limbs of the “Y” are the biliopancreatic and Roux limbs. This type of anastomosis is used in several procedures, such as pancreaticoduodenectomy (Whipple operation) ( Fig. 2 ); bariatric surgery; and Roux-en-Y reconstructions after gastric resection, liver transplant, and certain biliary tract operations. ERCP in patients with Roux-en-Y anatomy can be difficult because of the length of bowel that must be traversed. The length varies depending on the type of surgery performed, with bariatric operations, such as Roux-en-Y with gastric bypass (RYGB), often resulting in the longest limbs ( Fig. 3 ). Additionally, some types of Roux-en-Y reconstructions (eg, bariatric surgery or gastric resections) do not alter the native papilla but add an additional challenge of successful cannulation because the endoscopist must approach the papilla from the reverse position.
Approach to the bile duct in gastrojejunostomy and Billroth II
The most commonly used endoscopes to perform ERCP in patients with gastrojejunostomy (short-limb) or Billroth II anatomy are duodenoscopes and gastroscopes. Obstacles to success include difficulties in identifying the afferent limb, advancing the endoscope through the afferent limb to the papilla, and cannulating from an inverted or caudal angle. Techniques and instruments that facilitate successful biliary access in these patients are discussed next. Performing biliary interventions can also be challenging, and are discussed in a subsequent section.
Duodenoscope
The duodenoscope remains a popular choice among biliary endoscopists for patients with Billroth II or similar anatomy. Obviously, the afferent limb must be of limited length to allow the duodenoscope to reach the papilla. Because of the side-view optics, identifying the afferent limb and negotiating the duodenoscope to the correct position can be difficult. Several techniques may help facilitate successful insertion of the duodenoscope. Use of fluoroscopy during insertion may confirm that the endoscope is heading toward the expected location of the papilla. Changing patient position or applying external compression may help advance duodenoscopes across acute angulations at the gastrojejunal anastomosis. Using a gastroscope before duodenoscopy may also allow the endoscopist to confirm the correct limb and evaluate for any unexpected anatomic angulations or variations. The correct limb can be marked with submucosal ink tattoo, or a guidewire can be left in place to facilitate immediate duodenoscope insertion.
After the duodenoscope is advanced to the second portion of the duodenum, the papilla is usually readily visible. The presence of an elevator allows for additional fine control during cannulation attempts and subsequent instrumentation. When seeing the papilla “head-on” from the second portion of the duodenum, the reverse angle of approach for biliary cannulation toward the 5-o’clock position compared with the usual 11- to 12-o’clock position for standard ERCP should be recognized ( Fig. 4 ). The authors recommend using standard, straight cannulas with or without guidewires for selective biliary access. These cannulas can also be “pushed” against the duodenal wall to create a reverse angulation (from the usual angulation produced by the elevator), which improves the trajectory toward the biliary orifice.
The largest published experience of ERCP in Billroth II anatomy is in association with duodenoscopes. In larger series (each including 45–110 patients with Billroth II distal gastrectomies), success rates using duodenoscopes for reaching the papilla and for selective biliary cannulation are 70% to 97% and 60% to 91%, respectively.
Gastroscope Versus Duodenoscope
Some experts advocate using gastroscopes over duodenoscopes in Billroth II anatomy. The main advantage of this instrument is the ease of recognizing and negotiating the afferent limb. The front-view optics facilitates advancing the endoscope through the afferent limb and into the second portion of the duodenum. However, cannulation can be difficult, because the papilla may not be located in a favorable position with respect to the instrument channel. Lack of an elevator also compromises fine control of cannulation tools and accessories. That said, a few centers have reported high cannulation rates, ranging from 81% to 87%, using front-view endoscopes in ERCP in Billroth II.
One prospective, randomized trial directly compared gastroscopes with duodenoscopes in a group of 45 patients with Billroth II in need of ERCP. Cannulation rates trended higher (87% vs 68%) in patients undergoing ERCP using gastroscopes. However, these results should be interpreted with caution because all cannulation “failures” in the duodenoscope group (total of 7) occurred in settings where the papilla was not reached. These were attributed to perforations during endoscope insertion (N = 4); difficulty in entering or negotiating the afferent limb (N = 2); or abdominal pain during insertion (N = 1). Other centers have reported high cannulation rates with duodenoscopes when the papilla is reached. The cannulation failures in the gastroscope group were related to long afferent limbs (N = 2) or failed cannulation despite reaching the papilla (N = 1).
When using a gastroscope, one method to facilitate successful ERCP is the use of a transparent cap on the tip of the endoscope ( Fig. 5 ). This allows the operator to better visualize the papilla by displacing any adjacent folds, stabilizing the endoscope during attempted cannulation, and optimizing the angle of approach. It also may assist the endoscopist in negotiating any acute angles in the afferent limb during intubation. In a case series from Korea, cap-assisted ERCP with a gastroscope allowed for successful cannulation and biliary therapy in 10 (100%) of 10 patients.
An oblique-viewing gastroscope may combine the relative benefits of gastroscopes and duodenoscopes for Billroth II ERCP. Use of this instrument was first reported by Law and Freeman in 2004, in which it was successfully used to perform therapeutic ERCP in a single patient. Subsequently, a larger case series reported use of this endoscope with a high success rate of reaching the papilla (88%) and high cannulation success (95%) in patients with Billroth II anatomy. Unfortunately, these instruments were prototype models that are not currently available commercially for widespread use.
Complications
Performing ERCP in Billroth II anatomy increases the risk of complications. In addition to the usual complications that are associated with ERCP, there is the added concern for perforation while attempting to traverse the afferent limb, because perforations can occur near the gastrojejunal anastomosis. This may occur with use of either gastroscopes or duodenoscopes. Perforations can also occur within the afferent limb itself, and these are usually related to passage of side-viewing duodenoscopes under limited visibility.
The previously mentioned randomized trial comparing gastroscopes with duodenoscopes in patients with Billroth II did reveal a higher perforation rate with the duodenoscope (4 of 22) compared with the gastroscope (0 of 23). However, other series with larger numbers of patients (100+) have suggested more modest perforation rates ranging from 2% to 6%.
Ultimately, the decision of whether to use a duodenoscope or gastroscope is likely best guided by personal experience and operator success rates. However, one should be prepared to switch to the alternative technique based on intraprocedural findings. Some studies have shown success even when the initial method fails. In patients with long afferent limbs in which there is difficulty reaching the papilla, techniques used to perform ERCP in patients with Roux-en-Y anatomy should be considered, as discussed next.
Approach to the bile duct in Roux-en-Y reconstruction
Performing ERCP in patients with Roux-en-Y anatomy was once thought to be virtually impossible because of the long length of interposed bowel. This is of special concern in bariatric operations with long Roux limbs. Endoscopic techniques and tips to facilitate successful biliary access in patients with Roux-en-Y anatomy are discussed next ( Table 1 ).
| Technique | Success in Reaching Biliary Orifice a | Success in Cannulation, if Biliary Orifice Reached a | Success in Therapy After Cannulation, if Indicated a | Comments |
|---|---|---|---|---|
| Push enteroscopy or colonoscopy | 67%–84% | 95%–100% | 86%–100% | Widely available Reasonable first choice in short-limb Roux-en-Y Use of colonoscope allows wider array of ERCP accessories |
| Deep enteroscopy: DBE SBE Short DBE Spiral | 74%–100% 55%–92% 86%–97% 64%–77% | 85%–100% 83%–100% 90%–98% 63%–90% | 92%–100% 77%–100% 100% 88%–100% | No major differences among technologies Limited ERCP accessories through enteroscopes Various methods to advance “shorter” endoscopes may improve cannulation and therapy |
| ERCP by gastrostomy or laparoscopic- assisted | 100% | 100% | 100% | More invasive and resource intensive than purely endoscopic methods Highest success rates Best option for patients requiring multiple ERCPs Better than deep enteroscopy–assisted ERCP for long-limb Roux-en-Y |
a When possible, success rates were calculated using the actual number of ERCPs as denominator; in some studies, limitations in the reported data required using the number of patients as denominator.
General Considerations
Earlier reports of attempting ERCP using duodenoscopes in patients with Roux-en-Y anatomy revealed poor success rates (33%), essentially caused by inability to reach the biliary orifice. Push enteroscopy (using enteroscope or pediatric colonoscope) and deep enteroscopy technology (eg, balloon or spiral enteroscopy [SE]) may allow the endoscopist to overcome the technical limitations of insufficient length. However, there remain several challenges to successful ERCP when using either of these platforms:
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Maneuverability and reaching the biliary orifice: Although the enteroscope may be of sufficient length, distal advancement down the Roux limb and up the biliopancreatic limb may still be difficult because of angulations, adhesions, and looping in the small bowel. Deep enteroscopy technology confers some advantage over standard push enteroscopy with regards to this issue. Additionally, fluoroscopy to aid in identifying and eliminating loops and to verify appropriate advancement toward the right upper quadrant may be of benefit.
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Limited ERCP accessories: There are limited ERCP tools that are compatible with longer-length endoscopes and their smaller-size accessory channels. The authors recommend preparing a special “ERCP tool kit” that matches appropriate length and size ERCP instruments to the type of endoscope used. Tools that may be needed for biliary access or therapy should be anticipated.
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Cannulation difficulty: As discussed with regards to cannulation difficulty when using gastroscopes in Billroth II anatomy, attempting cannulation with a front-view pediatric colonoscope or enteroscope from a caudal angle can also be a challenge in Roux-en-Y reconstruction. In patients with bilioenteric anastomoses (eg, post–Whipple surgery), this is not an issue. However, in patients with a native papilla (eg, post-RYGB), the papilla may be at an unfavorable angle with respect to the instrument channel. Lack of an elevator may also limit the fine control that is often needed during cannulation.
Push Enteroscopy
Colonoscopes and push enteroscopes are available in most endoscopy units, and may be a reasonable first choice, especially in patients with relatively short Roux limbs. The first report of a pediatric colonoscope used to perform ERCP on a patient with Roux-en-Y reconstruction was published in 1988. A subsequent case series of 18 patients with Roux-en-Y reconstruction (including three with gastric bypass) revealed high success rates for reaching the papilla or ductal anastomosis (86% for enteroscope, 82% for pediatric colonoscope). Cannulation rates in this series were also high (94%), and included five of six procedures in patients with native papilla.
Given the larger experience with duodenoscopes in ERCP in Billroth II, some experts have developed methods to introduce duodenoscopes to the papilla in Roux-en-Y anatomy. One technique involves advancing a colonoscope to the papilla, followed by placing a guidewire in the biliopancreatic limb. A duodenoscope can then be advanced over the wire or can be pulled into the biliopancreatic limb using an inflated wire-guided balloon as an anchor. A case series highlighting this technique showed successful insertion of duodenoscopes to the papilla in 10 (67%) of 15 with long-limb Roux-en-Y anatomy, with subsequent diagnostic or therapeutic ERCP success in all 10 of these patients.
Deep Enteroscopy
Deep enteroscopy platforms were developed to help endoscopists evaluate and reach the distal small bowel. Double-balloon enteroscopy (DBE) was first reported in 2001. Single-balloon enteroscopy (SBE) and SE were developed by other manufacturers and became available in the United States about 6 to 7 years later. All of these technologies are similar in that they are designed to allow deeper endoscope insertion into the small bowel, and therefore all of these may facilitate reaching the biliary orifice after Roux-en-Y reconstruction.
Balloon enteroscopy
DBE involves two separate inflatable balloons at the tip of the enteroscope and overtube. By alternating inflation-deflation and reduction-advancement on both the enteroscope and overtube, the endoscope tip can be advanced to the further depths of the small bowel ( Fig. 6 ). Use of DBE to reach the bypassed stomach in a small series of patients with RYGB was first described in 2005.
Since then, numerous case reports have emerged using DBE for ERCP in Roux-en-Y anatomy. Larger series with 13 to 31 patients have published success rates of reaching the biliary orifice and subsequently achieving successful cannulation in 74% to 100% and 85% to 100%, respectively; in the subset of patients requiring interventions, therapeutic success was reported in 92% to 100% after successful cannulation. As might be expected, cannulation and endobiliary therapy are more difficult in Roux-en-Y patients with native papilla (eg, post–gastric bypass) compared with Roux-en-Y patients with bilioenteric anastomoses.
SBE uses only one balloon at the tip of the overtube, but essentially similar types of maneuvers are performed to help advance the enteroscope distally. Five large case series involving 13 to 50 patients have reported successful reaching of the biliary orifice in 55% to 92%, subsequent successful cannulation in 83% to 100%, and successful therapy in 83% to 100% among those needing interventions based on diagnostic ERCP findings.
“Short” endoscope – balloon enteroscopy
The longer length of the standard enteroscope used for balloon enteroscopy limits the types of ERCP accessories that may be used. For DBE and SBE, techniques have been developed to allow use of shorter-length endoscopes that can accommodate a larger array of standard ERCP catheters. Manufacturers of the DBE platform have developed a shorter system that uses an enteroscope with a 152-cm working length. In three of the largest case series reporting outcomes of a “short” DBE system for Roux-en-Y ERCP involving 20, 68, and 79 patients with altered anatomy, diagnostic cholangiography was successfully obtained in 81% to 95%, with treatment success in almost all cases requiring therapy.
Another technique that has been used with SBE involves modifying the overtube. After the papilla is reached, the longer enteroscope can be removed while maintaining overtube position near the biliary orifice. A shorter-length gastroscope can then be inserted to the area of the papilla (or bilioenteric anastomosis) by a slot created in the side of the overtube at a distance that allows the instrument to extend past the tip of the overtube. Itoi and colleagues described this technique and managed successful therapeutic ERCP in 10 (77%) of 13 patients with altered anatomy, including 8 (72%) of 11 with intact papilla. The main benefit of allowing the endoscopist to reach the biliary orifice with a short length endoscope is the availability of a wider spectrum of ERCP accessories that maximize the chances for successful cannulation and therapy.
Spiral enteroscopy
SE uses an endoscope in conjunction with a rotational overtube with a spiral design on the exterior surface. By using clockwise rotational movements the endoscopist can “engage” the small intestinal mucosa and pleat the folds, allowing for deeper access ( Fig. 7 ). In studies focusing on evaluation of small bowel disorders, SE offers shorter examination time compared with DBE but at the cost of less depth of insertion. With respect to using this platform for ERCP in altered anatomy, it is not known whether a decreased insertion depth would be relevant; reaching the biliary orifice is all that is needed. However, a potentially decreased time to reach the biliary orifice would certainly be beneficial, because the time required to perform the ERCP portion of the procedure can be substantial.
Related posts:
Endoscopic Advances in Biliary Disease
Pre-ERCP Imaging of the Bile Duct and Gallbladder
Endoscopic Evaluation of Bile Duct Strictures
Endoscopic Management of Benign Bile Duct Strictures
Endoscopic Approach to the Patient with Motility Disorders of the Bile Duct and Sphincter of Oddi
Endoscopic Ultrasonographic Access and Drainage of the Common Bile Duct
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