ERCP in Surgically Altered Anatomy

Billroth I

In a Billroth I surgery, only the antrum and pylorus are removed and the stomach is attached to the duodenum along its greater curvature ( Fig. 31.1 ). Endoscope passage into the duodenum is typically easier than usual because of the loss of the pylorus, but the papilla is actually harder to find. As expected, both the major and minor papillae are more proximally located than usual. In the short-scope position, the papilla is seen after an exaggerated rotation of the endoscope. Additionally, anchoring the endoscope is difficult without the antrum and pylorus, and achieving a stable scope position for cannulation may be quite difficult. Occasionally, working in the long-scope position may be more desirable because the papillary orifice is better visualized and the scope is more stably situated. Because it is difficult to cannulate the bile duct in a sharply retrograde fashion, using a sphincterotome and guidewire in combination may overcome the intrinsic issues in Billroth I cannulation.

Billroth II

Before proton pump inhibitors were introduced, peptic ulcer surgery was common. Currently, most Billroth II procedures are done for resection of distal gastric cancers and involve antrectomy and creation of a gastrojejunostomy. The result is an end (stomach)-to-side (jejunum) anastomosis with two jejunal lumens ( Fig. 31.2, A, B ) immediately beyond the gastric staple line. The afferent limb travels proximally and ends as a duodenal stump proximal to the major and minor papillae, whereas the efferent limb restores intestinal continuity with the rest of the GI tract. The major papilla is typically located within a few centimeters of the duodenal stump, and its orifice is pointing down at the endoscope.

There are several considerations when performing ERCP in a Billroth II stomach, the first of which is the choice of endoscope. It was initially believed that an end-viewing endoscope was preferred because of the ease in navigating the convoluted small bowel and cannulating the biliary orifice. Many experienced biliary endoscopists have since switched to duodenoscopes to take advantage of the large channel, instrument elevator, and unique side-viewing design to inspect the papilla. Selection of endoscopes may be simply a matter of personal preference, as a Korean prospective, randomized study demonstrated no difference between side-viewing and end-viewing endoscopes in cannulation success and sphincterotomy. In fact, end-viewing endoscopes were safer to use. Regardless of which endoscope is used, it is difficult to perform ERCP in a Billroth II gastrectomy. In a study involving 185 Billroth II ERCP procedures, the failure rate was as high as 34%.

There is no definite way to correctly identify the afferent lumen in a Billroth II gastrectomy, even though there is the common impression that it arises from the more awkwardly located orifice. The afferent limb can be attached to the stomach along either the lesser (antiperistaltic) ( Fig. 31.2, A ) or greater (isoperistaltic) curvature ( Fig. 31.2, B ). Scope passage with an end-viewing device is intuitive, and the major challenge is in visualizing and cannulating the papilla. Because the instrument channel of most endoscopes is located at the 5 to 7 o'clock position, it is best to situate the papilla at the bottom of the endoscopic view. Unfortunately, typically a sharp angle is encountered between the transverse and descending duodenum that makes visualizing the papillary orifice difficult. A soft transparent cap at the tip of the end-viewing endoscope may help stabilize the papilla during cannulation.

Scope passage with a side-viewing duodenoscope can be very difficult or even impossible and begins with attempting to gain entry into the afferent lumen. Endoscope passage is even more difficult if the afferent limb is sutured to the lesser curvature after it has exited the gastrojejunostomy, as this form of operation creates a fixed and significantly angulated point of entry ( Fig. 31.3, A, B ). The technique of entering the gastrojejunostomy orifice is the same as for the pylorus. When the lumen can be visualized only in the retroflexed (maximally up-angulated) position, attempting to glide the scope gently toward it rarely works. Suctioning excess gastric air may make gliding a little easier. A technique of entering the lumen by rotating the endoscope 180 degrees at the orifice and pointing the tip of the scope downward until the small bowel lumen is clearly in sight can be used. This can theoretically be done with the endoscope facing the opening rather than “backing in.” However, the endoscope is blinded by mucosa and visual inspection during the maneuvering is more difficult. Hand-compressing the midabdomen or extending a polypectomy snare into the intended lumen has been reported to assist in intubation of a difficult gastrojejunostomy orifice. Passage of the duodenoscope alongside or over a stiff guidewire that has been placed into the afferent limb with an end-viewing endoscope may occasionally be helpful. Even in tertiary biliary centers, the rate of failure to enter the afferent limb is as high as 10%.

Once the side-viewing duodenoscope has securely entered the afferent jejunal lumen, passage forward is safe and effective by constantly orientating the intestinal channel in the 6 o'clock position ( Fig. 31.4, A ). This would simulate the view of driving a car in a long tunnel. It is common to see two lumens when a duodenoscope is partially retroflexed, and it creates confusion regarding where to advance the endoscope. A good rule of thumb is to orientate the two lumens along the vertical midline, and the lower lumen is the one that the endoscope should enter ( Fig. 31.4, B ). Natural intestinal redundancy and tortuosity rarely allow unimpeded forward advancements. Rather, successful passage requires a combination of gentle rotation, dial redirection, and alternating withdrawal and advancement. The forward blinded-gliding technique, commonly applied in colonoscopy passage, should not be practiced because of the risk of perforation. For the same reason, care must be taken to minimize sudden or forceful manipulations. One series reported a 5% perforation rate when advancing duodenoscopes through the afferent limb. In another study, jejunal perforation occurred in 18%. Using an older, more flexible duodenoscope may reduce the chance of traumatizing the intestinal wall. Minimizing air insufflation helps keep the lumen straight and the bowel wall soft and pliable. Abdominal compression or rotation of the patient is occasionally effective in advancing around seemingly improbable turns. With experience and special care, an acceptable risk of perforation can be achieved.

After passing some distance, it is wise to take a fluoroscopic picture to confirm that the endoscope is passing through the transverse duodenum ( Fig. 31.5 ). If the tip of the endoscope is seen in the pelvis, it is likely to be in the efferent limb and should be withdrawn to search for the other intestinal orifice. Some afferent limbs seem to be longer and more tortuous than others. This impression is indeed correct, as the afferent loop may be created in antecolic fashion over the transverse colon ( Fig. 31.6, A, B ). Correct endoscopic intubation of the afferent loop is readily confirmed if fluoroscopy shows that the scope has quickly crossed the midline into the right upper abdomen.

On the way to the proximal duodenum, an anastomosis that connects the afferent to the efferent limb may be encountered, which is indicative of a Braun procedure, a modification of the Billroth II operation. This is performed to reduce bile reflux into the stomach or to lessen the chance of duodenal obstruction ( Fig. 31.7 ) and is recognized because of the finding of three exiting lumens. It should not influence the endoscopic passage if the scope does not cross the anastomotic stable line. On some occasions the duodenal stump, which appears as a blind sac with a distinctly flat mucosa and possibly surgical staples, is reached without identifying the major papilla. The minor and then major papilla should be readily identified upon gradual withdrawal of the endoscope ( Fig. 31.8, A–C ).

The major papilla is almost always found near the 12 o'clock position of the duodenum when a duodenoscope is used ( Fig. 31.8, C ). If the intestinal lumen is kept in view ahead of the endoscope, the bile duct should be straight or slightly to the right ahead of the papillary orifice ( Fig. 31.9, A and Fig. 31.10 ). To keep the cannulating catheter or guidewire tangential to the duodenal wall for biliary access, the papilla should not be approached up close ( Fig. 31.8, C ). Rather, the scope should be pulled back slightly with its elevator partially lowered for catheter passage. Conversely, the pancreatic duct is easier to cannulate by advancing the endoscope close to the papilla and keeping the elevator in a lifted position ( Fig. 31.8, B ). Some endoscopists prefer to use straight-tip catheters for biliary cannulation, whereas others like to use straight guidewires. However, perhaps the most effective way to enter the bile duct is to use a catheter bent into an S-shape, with its tip pointing downward ( Fig. 31.9, B ). A cap-assisted approach has been described to improve cannulation of a Billroth II papilla when an end-viewing endoscope is used ( Fig. 31.11 ). On some occasions when pancreas divisum is suspected, the minor papilla should be correctly identified for cannulation. As a rule, it is located slightly farther away from (cephalad to) and to the left of the superiorly located major papilla ( Fig. 31.8, A and Fig. 31.10 ).

Biliary sphincterotomy is accomplished using either a wire-guided Billroth II sphincterotome or a needle knife to cut over an indwelling biliary stent. A Billroth II sphincterotome is designed in an opposite fashion to a conventional traction sphincterotome, with its cutting wire loosened to form a half loop over a straight sphincterotome catheter. With the wire protruding, the sphincterotome is pushed forward to cut the papillary hood along the 6 o'clock position of the superiorly located papilla. Sphincterotomy done in this manner is slightly less well controlled than in the normal setting because of the pushing motion and suboptimal visualization of the proximal papillary mound. A modified sphincterotome that forces its tip into an S-shape when the cutting wire tightens may also be used to perform sphincterotomy in this setting. However, many endoscopists choose needle-knife cutting over a biliary stent because it avoids injury to the pancreatic sphincter and allows controlled tissue cutting. Balloon sphincter dilation, commonly done with an 8-mm balloon, is technically easy to perform and can be done as a solo therapy or in combination with a limited sphincterotomy. A randomized study showed that balloon sphincter dilation was just as effective as sphincterotomy at facilitating stone extraction, with fewer adverse events, in the Billroth II setting. Additionally, pancreatitis was not encountered.

Roux-en-Y Gastrectomy

Aimed to reduce reflux of pancreatic and biliary fluids into the stomach after a partial gastrectomy, Roux-en-Y gastrectomy creates a gastric outlet that appears similar to that of a Billroth II surgery. However, one end of this end-to-side anastomosis is a short blind stump ( Fig. 31.12 ). The other lumen, the Roux limb, extends around 40 cm before a jejunojejunostomy anastomosis is encountered. At this point two or three lumens ( Fig. 31.13, A, B ) will be identified, depending on whether the two jejunal limbs are connected end-to-side ( Fig. 31.13, C ) or side-to-side ( Fig. 31.13, D ). If done side-to-side, one of the three outlets will be a short blind stump. If the afferent limb is correctly entered, the endoscope will pass sequentially up the proximal jejunum, ligament of Treitz, transverse duodenum, and finally the descending duodenum. This long path makes it nearly impossible for a 125-cm-long duodenoscope to reach the major papilla. Many longer-length endoscopes have been used to perform ERCP in this setting, including pediatric and adult colonoscopes and push enteroscopes. A special oblique-viewing endoscope, which is no longer available commercially, was reported to be useful for this purpose. Double-balloon enteroscopes, which can routinely reach the ileum per-os, were introduced to the United States in 2004 ( Fig. 31.14, A–D ). Their use in performing diagnostic and therapeutic ERCP in patients with Roux-Y hepaticojejunostomy was soon reported. Until now, all forms of deep enteroscopes, including single and enteroscopes used through a spiral overtube, are routinely employed for a variety of pancreatic and biliary conditions in this postoperative setting.

The challenge of performing ERCP in a Roux-en-Y gastrectomy patient lies not just in traveling a great length and recognizing the proper intestinal lumen but also in selectively cannulating the bile duct and pancreatic duct. It is common to pass the endoscope past the anastomosis into the efferent jejunal limb without recognizing the jejunojejunostomy. A clue to the vicinity of the anastomosis is the presence of bilious fluid. Once bile is seen, endoscope advancement should be slowed to identify the intestinal bifurcation. The afferent limb is always found across the circular rim of anastomosis and is typically entered via the straighter of the two orifices. All end-viewing endoscopes have an inherent difficulty in visualizing the major papilla because of its location along the sharply turned, interior aspect of the duodenal C-loop. Even when identified, cannulation is extraordinarily difficult because of the awkward orientation and unstable endoscope positioning ( Fig. 31.15, A–B ). In the hands of ERCP experts, the success rate is a mere 67%. Yamamoto and colleagues reported the success of performing diagnostic and therapeutic ERCP with a double-balloon enteroscope in five patients. Interestingly, the authors fitted a small plastic cap on the tip of the enteroscope to enable cannulation. The added advantage of a plastic cap was also reported by another endoscopy group using the single-balloon enteroscope. Given the difficulty and frequent failure of performing ERCP in this postoperative anatomy, it is best to refer these types of cases to a tertiary biliary center or choose an alternative method such as a percutaneous transhepatic or endoscopic ultrasonography (EUS)–guided approach. Performing ERCP with the intent to evaluate and treat a pancreatic condition is particularly problematic, as a transhepatic procedure cannot intubate the pancreatic duct. We prefer to use a long-length (320 cm) 5-Fr diagnostic ERCP catheter preloaded with a hydrophilic guidewire to perform cannulation when a double-balloon or single-balloon enteroscope is employed. Contrast can be injected with this setup if a Y-adapter is used. To circumvent the technical challenge in performing ERCP with an ultralong endoscope, some endoscopists advocate an intraoperative transjejunal method. This surgery-assisted procedure creates an enterotomy at 20 cm distal to the ligament of Treitz to allow a gas-sterilized duodenoscope to advance up the afferent limb.

Total Gastrectomy

Usually performed for gastric cancer or postoperative complications, total gastrectomy leads to an end-to-side esophagojejunostomy. One lumen of the esophagojejunostomy is a blind end, whereas the other is the jejunal Roux limb ( Fig. 31.16 ). A short distance distal is a side-to-side or end-to-side jejunojejunostomy to receive pancreatic and biliary contents. Similar to Roux-en-Y gastrectomy, the peroral endoscope must enter the proximal jejunum before arriving at the duodenum. Unlike in Roux-en-Y partial gastrectomy, a duodenoscope can actually reach the major papilla because of its straighter and shorter upper GI route. Once the major papilla is identified with the duodenoscope, the approach to ERCP cannulation and therapy is as for Billroth II anatomy. When a duodenoscope cannot negotiate the jejunojejunostomy or is too short to reach the descending duodenum, a long end-viewing endoscope must be used. Again, the challenge lies in cannulating and treating disease processes without the benefits of an elevator and side-viewing capability. The same techniques used for a Roux-en-Y gastrectomy apply to this situation.

Loop Gastrojejunostomy

The indications for gastrojejunostomy without resection of any part of the stomach include an obstructing pancreatic head mass, benign chronic duodenal obstruction, and unresectable duodenal malignancy with stricture. Gastrojejunostomy may occasionally be done in combination with surgical closure of the pylorus to prevent food from entering a perforated duodenum (pylorus exclusion). When inspecting the stomach during ERCP, this loop gastrojejunostomy is usually located along the dependent portion of the stomach. However, it may be slightly toward the anterior or posterior wall along the greater curvature ( Fig. 31.17, A, B ). Although most anastomoses for bypass of obstructive diseases are expected to be large, some of these gastrojejunostomy openings appear to be quite small. Immediately through the rim of an anastomosis two jejunal orifices will be found, and either opening can be the one that leads to the afferent limb. When it is the more distal orifice, an antiperistaltic connection has been performed and the afferent limb is relatively short. This distance becomes longer if the surgery is done in the antecolic fashion because the intestine has to drape over the transverse colon. This limb may become even longer if the gastrojejunostomy is created in an isoperistaltic manner. On some occasions a second anastomosis is noted beyond the gastrojejunostomy. It may be a Braun procedure ( Fig. 31.17, B ), done to add further bypass of contents between the afferent and efferent limbs to reduce alkaline biliary reflux into the stomach or to provide a safety net to minimize the chance of an afferent limb obstruction. If the endoscope passes through a Braun anastomosis, it has a 50% chance of returning to the stomach via the other limb of the gastrojejunostomy. When a Braun procedure is suspected, it is best to stay on the same intestinal limb without advancing through the second anastomosis. If the loop gastrojejunostomy is combined with suture closure of the pylorus as a short-term fix for duodenal perforation, the pylorus may reopen within a few months. It is best to first examine whether the pyloroduodenal stricture is patent before going through one of the gastrojejunostomy lumens.

Because the major papilla is intact in this setting, a duodenoscope is preferred for ease of inspection and cannulation unless it is proven to be of inadequate length. In practice, reaching the descending duodenum is often not the key issue. Instead, inspection and cannulation are a bigger challenge, because most of these cases have a highly stenotic duodenum as the reason for creating the loop gastrojejunostomy. Fortunately, duodenal obstruction from pancreatic head cancer is often located proximal to the major papilla, leaving sufficient room to carry out an ERCP. In the event of inadequate spacing, balloon dilation of the duodenal stricture can be performed, but the resultant mucosal trauma and hemorrhage may add more obstacles to the procedure. A transhepatic approach to biliary drainage, either percutaneously or using EUS guidance, is frequently necessary in this situation. Alternatively, a rendezvous procedure, in which a transhepatic catheter or guidewire is passed across the biliary sphincter, via percutaneous transhepatic or EUS guidance can be done for endoscopic access. There are occasions when the bypass surgery is done for gastroparesis and performing an ERCP in the usual antegrade fashion is preferred. In this situation, the duodenoscope has to be rotated slightly to glide along the anterior gastric wall to reach the pylorus and avoid inadvertently passing into the gastrojejunostomy.

Duodenal Bypass

Duodenal perforations are occasionally treated by a duodenojejunostomy. Even though this form of operation is uncommon, identification of two or more intestinal lumens beyond the pylorus or at the descending duodenum may create confusion for the endoscopist. If there is no associated duodenal narrowing, the procedure is straightforward and the key is to carefully inspect each lumen until the major papilla is found. If a mildly to moderately stenotic duodenal lumen is found, gentle balloon dilation may be attempted to ease passage of the endoscope. Alternatively, a pediatric ERCP scope with a 7.5-mm outer diameter and 2.0-mm instrument channel can be used. However, the small working channel allows only limited therapeutic possibilities such as sphincterotomy, stone extraction, and placement of a 5-Fr stent. On very rare occasions, duodenoduodenostomy ( Fig. 31.18, A, B ) is done on a newborn to bypass a congenital duodenal stricture or annular pancreas. Depending on the level of the stricture relative to the major papilla when this patient reaches adulthood, the endoscopist may find the papilla recessed above or below the stricture as if it was located inside a deep-seated diverticulum. The techniques and challenges of cannulating the ampullary orifice are very similar to those with the usually identified duodenal diverticulum.

Malabsorptive Jejunoileal Bypass

This form of weight-reduction surgery is mentioned primarily for historical purposes. It is neither practiced today nor does it affect the performance of ERCP. Rarely, a consultation for ERCP may be requested for a patient with a prior jejunoileal bypass surgery because of jaundice. In this case the cause of jaundice is more likely hepatic failure rather than biliary tract disease. This operation, popular before 1980, may consist of transecting and connecting a large jejunoileal segment to the distal colon. Alternatively, the proximal jejunum is transected and connected to the distal ileum in an end-to-side manner, excluding a long jejunum and ileum from contact with intestinal nutrients ( Fig. 31.19 ). The result of this form of operation is a very short functioning small bowel that causes weight loss by malabsorption and maldigestion. Chronic diarrhea, stone disease, and fatal liver dysfunction are reasons that all patients who underwent this surgery should have the bypass reversed. Theoretically, if such a patient needs an ERCP, it can be done in the normal manner, although one of the editors of this book has done an ERCP successfully retrograde through the colon using a balloon-assisted enteroscope.