Background: Alterations in the anatomy of the upper gastrointestinal tract may pose a challenge to the endoscopist, especially if interventions to the biliary system are indicated in patients with altered continuity of the gastrointestinal tract, impeding to reach the papilla with conventional ERC techniques. The success of any endoscopic intervention in this setting depends on optimal knowledge on the postoperative anatomy in each individual patient. Summary: If conventional endoscopic retrograde cholangiopancreaticography is impossible, biliary tree access can be achieved by applying novel techniques including endosonography-directed approaches, overtube-assisted approaches or spiral enteroscopy to reach the papilla or biliodigestive anastomosis in case of long limbs, percutaneous or even hybrid approaches. This review gives an overview of the most common techniques. Key Message: The choice of endoscopic approach should be individual in each patient, taking indication and urgency, type of anatomic alteration, local expertise, patients’ characteristics and preferences as well as prognosis into account. Early interdisciplinary discussion is essential to choose the procedure with the optimal risk-benefit ratio in the individual patient.

Endoscopy in patients with a history of gastrointestinal surgery is challenging and requires a profound understanding of the altered anatomy before the procedure is planned. It is of particular importance to take a detailed medical history on previous abdominal surgery in any given patient and findings of potential previously performed endoscopies to enable successful intervention and correct report.

After resections with primary anastomosis and preserved continuity of the gastrointestinal tract (i.e., hemicolectomy, gastro-esophageal resection) standard endoscopic procedures with no or little modifications are generally possible. Particularly, in patients with intestinal stomas, endoscopy of the small and large bowel may often even be easier to perform than regular colonoscopy or intestinoscopy, and can in general be performed with standard endoscopes. However, bowel preparation schedules may require modifications to adapt to the flow of nutrients and lavage fluids (i.e., with double-barreled ileostomy).

Endoscopies in patients with altered continuity of the upper gastrointestinal tract are more challenging, especially if access to the duodenal papilla or biliodigestive anastomosis is to be achieved in patients requiring interventions of the hepatobiliary system after B-II-gastrectomy or Whipple procedure. Additionally, alternative endoscopic routes and procedures to facilitate successful endoscopic retrograde cholangiopancreaticography (ERCP) to treat hepatobiliary pathologies are needed in patients who have undergone bariatric surgery with Roux-en-Y gastric bypass (RYGB). The number of these bariatric interventions is increasing to treat obesity, and the rapid weight loss is associated with a higher risk of gallstones and their complications. Up to 35% of patients post-gastric bypass develop cholelithiasis, and about 10% of these present with biliary obstruction [1, 2]. Advances in endoscopic techniques, particularly the more widespread availability of endoscopic ultrasound (EUS)-based interventions, have augmented the spectrum of options for endoscopists. This review focuses on interventions of the biliopancreatic system in postoperative patients with altered upper gastrointestinal anatomy.

ERCP is considered the standard procedure for the treatment of biliary leaks, benign or malignant strictures, and intraluminal content like gallstones. In patients with unchanged anatomy, the primary success rate is estimated to range between 90 and 95%. However, in patients with surgically altered anatomy success rates decrease dramatically and are reported to be approximately 55% [3-5]. After hepatobiliary and upper gastrointestinal surgery, different approaches of anatomic reconstruction hamper endoscopic access to the biliary system (Table 1). In addition, postoperative adhesions, strong curvature of the intestine, long afferent loops, individual surgical peculiarities, and different distances from defined marks impede the procedural success. The three mayor steps in successful ERCP in patients with altered anatomy include reaching the papilla or biliodigestive anastomosis, cannulation of the duct, and finally performing the planned intervention [6].

Table 1.

Surgically altered situations hampering the access to the biliary system

Surgically altered situations hampering the access to the biliary system
Surgically altered situations hampering the access to the biliary system

Due to changes of the position of the biliary ostium, standard duodenoscopes are not useful to intervene in these patients. Innovations of endoscopic techniques improved the rate of successful endoscopic interventions in patients with surgically altered anatomy. By the end of the last century, the first case series were published using enteroscopes and pediatric colonoscopes for ERCP in patients with long-limb surgical bypasses.

Balloon enteroscopy was reported to ameliorate the rate of successful interventions especially when using short single balloon-enteroscopes (SBE) with working channels above 3.2 mm enabling the use of standard ERC materials, which is excluded when using longer endoscopes or endoscopes with a smaller working channel. The papilla can then be opened by various techniques, including the use of reverse sphincterotomes (BII-papillotome), cutting in 5 o’clock direction, needle-knife sphincterotomy guided by a biliary endoprosthesis or balloon papilloplasty. A recent meta-analysis including 1227 SBE-assisted ERC procedures found a pooled success rate of 86.6% [7]. Conventional SBE showed lower success rates compared to short SBE (82.9 vs. 92.8%). This finding has to be evaluated considering the higher rate of Roux-en-Y-reconstruction in the group treated with standard SBE. Success rates comparing double balloon and single balloon ERC were similar in older studies [8]. Recent innovations like motorized spiral enteroscopy have the potential to increase the access rate to the biliary system due to the facilitated forward push and the large diameter of the working channel [9].

The most common situations of surgically altered anatomy with regard to access to the biliary system are described in Table 1. The outcome of the endoscopic procedure is determined not only by the intervention itself but is significantly influenced by the prearrangement of the endoscopy. The endoscopist should spend sufficient time to understand the individual anatomy of the patient. Information on the type of resection and reconstruction, length of the limbs, and types of anastomoses are needed [9]. In some cases, magnetic resonance cholangiopancreatography (MRCP) prior to the endoscopic procedure may be helpful to plan the optimal access to the biliary system and optimal choice of equipment. Informed consent of the patient is as important as sufficient coagulation status. In some cases, peri-interventional antibiotic treatment should be considered [10].

Depending on the anatomical situation and the prognosis of the patient three different approaches for EUS-guided biliary interventions are established: EUS-rendezvous, EUS-guided antegrade approaches, and transluminal EUS-guided drainage.

Using intrahepatic or extrahepatic access via fine-needle aspiration needle, a guidewire is inserted into the biliary tree and pushed across the papilla or biliodigestive anastomosis. After changing the endoscope to a duodenoscope or pediatric colonoscope, the wire can be grasped and used for wire-guided cannulation and intervention.

Using intrahepatic access through the proximal stomach or extrahepatic access through the distal stomach or the duodenum, a guidewire is brought into the biliary system and then grabbed. Interventions such as dilatation and stent placement are performed using an echoendoscope.

This approach includes the creation of a de-novo fistula from the biliary system to the upper gastrointestinal tract. Depending on the access chosen EUS-choledochoduodenostomy characterized by a fistula between extrahepatic common bile duct and the duodenum and EUS-hepatogastrostomy characterized by a fistula between the left intrahepatic bile duct and the stomach have to be discriminated. In rare cases a fistula between the bile system and Roux-en-Y limb can be created alternatively.

All approaches listed can be performed in patients with surgically altered anatomy as well as in patients with native anatomy when the transpapillary biliary access is impossible, e.g., because of duodenoal stenosis or tumor occlusion. In patients with surgically altered anatomy EUS-guided access can be limited when the extrahepatic common bile duct was resected. In these cases, EUS-guided hepatogastrostomy is feasible.

Clinical studies report technical and clinical success of EUS-guided ERC in up to 95% of cases of patients with surgically altered anatomy and malignant biliary obstruction [11]. Another study combining the EUS antegrade approach and EUS-hepatogastrostomy showed lower technical success rates than in EUS-hepatogastrostomy alone (83.8 vs. 97.6%) with similar clinical success rates (90.3 vs. 90.2%) [12].

Comparing enteroscopy-assisted ERC and EUS-guided biliary drainage, EUS-guided biliary drainage was reported to have a higher clinical efficacy than enteroscopy-guided ERC (98 vs. 65.3%) with shorter duration of the interventions. The rate of adverse events, however, was higher in theEUS cohort (20 vs. 4%) with an overall significantly prolonged hospitalization (6.6 vs. 2.4 days) [13].

The endoscopic approach to the biliary tree in patients having undergone RYGB is sometimes impossible with both overtube-assisted ERC and EUS-guided intervention. In this scenario, laparascopy-assisted ERCP might be considered. In this hybrid technique, access to the excluded stomach is provided by laparoscopic creation of a gastrostomy. After introducing a standard duodenoscope through a trocar in the left upper quadrant, which is inserted into the stomach under laparoscopic visualization through the gastrostomy, ERC is performed in the usual manner [9]. Success rates of 90% with low complication rates have been reported [1].

Alternatively, even more advanced endoscopic techniques have been reported, either as EUS-directed transgastric ERCP with the creation of a gastric-gastric fistula with a lumen-apposing metal stent requiring the identification of the gastric remnant with an echoendoscope through the gastric pouch, the creation of a gastric-gastric access using a 19-gauge fine-needle aspiration needle and placement of a guidewire under fluoroscopic control or as percutaneous transgastric ERCP requiring the creation of a gastro-cutaneous tract [1]. Although the results of these approaches are favorable, complication rates are of significance and range up to 35.5% [14]. As these techniques require optimal logistic interdisciplinary cooperation and are extremely technically demanding, they should be reserved to highly specialized units. In case of unsuccessful endoscopic approach to the biliary tract, surgical common bile duct exploration is still a valid option.

Percutaneous approaches also allow fast access and drainage of the biliary tract if endoscopic treatment has failed and may be necessary especially in case of cholangitis with need of urgent drainage. Under sonographic or fluoroscopic guidance, the bile duct is accessed using a needle. Afterward, a guidewire is advanced through the needle followed by serial dilatation. This access can be used for diagnostic cholangiography, brush biopsy of stenosis, external or internal-external biliary drain, stent placement, or even cholangioscopy and laser lithotripsy [1, 15]. Therapeutic success rates in malignant biliary obstruction range between 61% and 79% [15]. Evidence with percutaneous lithotripsy for managing choledocholithiasis in patients after RYGB is limited. Possible complications of percutaneous transhepatic approaches to the biliary tract include but are not limited to bile leak, hemobilia, bleeding complications, pneumothorax, bilio-cutaneous fistula, and biliary stricutures and occur in up to 23% of interventions [16]. A summary of relevant studies on novel endoscopic techniques to reach biliary access in patients with altered anatomy is presented in Table 2.

Table 2.

Selected studies evaluating techniques to reach the biliary system in patients with surgically altered pancreaticobiliary anatomy

Selected studies evaluating techniques to reach the biliary system in patients with surgically altered pancreaticobiliary anatomy
Selected studies evaluating techniques to reach the biliary system in patients with surgically altered pancreaticobiliary anatomy

An altered anatomy of the upper gastrointestinal tract, e.g., after BII-resection, pancreaticoduodenectomy, or following bariatric surgery, challenges the endoscopist in the treatment of biliary disorders. If standard ERCP access fails, a step-up approach including EUS-guided rendezvous techniques, EUS-guided drainage, percutaneous interventions, and hybrid techniques should be applied. The choice of endoscopic approach should take indication and urgency, type of anatomic alteration, local expertise, patients' characteristics and preferences as well as prognosis into account. Early interdisciplinary discussion is essential to choose the procedure with the optimal risk-benefit ratio in the individual patient.

The authors have no conflicts of interest to declare.

The authors received no funding for this paper.

Benedikt Aulinger, Kerstin Schütte, and Christian Schulz: drafting of the manuscript and approval of the final version of the manuscript.

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Additional information

Benedikt Aulinger and Kerstin Schütte contributed equally to this work.

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