Biochemical abnormalities and transabdominal ultrasonography are often the first (and can be the most important) data a clinician utilizes to risk stratify a patient when deciding whether biliary endoscopy is indicated in the setting of acute pancreatitis . A study of more than 1000 patients evaluating biochemical parameters as predictors for choledocholithiasis prior to laparoscopic cholecystectomy found that presence of at least one abnormal liver function test (LFT) of the five (ALT, AST, alkaline phosphatase, total bilirubin, and GGT) had a sensitivity of 87.5 % [6]. Conversely, completely normal liver function testing had a negative predictive value for a positive ERCP of 97 %. Among biochemical testing, total bilirubin had the highest specificity (87.5 %), with a probability ratio of 3.9. Total bilirubin and alkaline phosphatase level were also demonstrated on multivariate analysis to be independent predictors for choledocholithiasis on ERCP although the positive predictive value of all the liver function tests was only 15 % [2]. Therefore, LFTs are most helpful when normal for excluding choledocholithiasis while even elevated total bilirubin and alkaline phosphatase may be false positives.

Similarly a normal bile duct on abdominal ultrasound rules out choledocholithiasis with 95–96 % negative predictive value. Of course the finding of a common bile duct (CBD) stone on ultrasound has very high specificity. Without a definite stone seen on imaging, the presence of multiple predictors for choledocholithiasis increases the positive predictive value. Predictors for choledocholithiasis were studied in patients presenting for laparoscopic cholecystectomy. This study found that an elevated bilirubin approaching 2 mg/dL combined with a patient age of 55 or greater and CBD dilation on ultrasound greater than 6 mm demonstrated a 75 % probability of predicting choledocholithiasis at the time of ERCP [6].

An ASGE position statement recommends risk stratification of patients with cholelithiasis based on biochemical liver testing and ultrasonography to categories of high, intermediate, and low risk for choledocholithiasis to determine who needs ERCP [2]. These categories stem from evidence-based predictors that are identified as “very strong” (CBD stone on transabdominal ultrasound, clinical ascending cholangitis , or bilirubin > 4 mg/dL), “strong” (CBD > 6 mm with gallbladder in situ on ultrasound, bilirubin level 1.8–4 mg/dL), and “moderate” (any abnormal biochemical liver test other than bilirubin, age greater than 55, and clinical gallstone pancreatitis) for identifying patients with choledocholithiasis on ERCP. Patients with the presence of any “very strong” predictor or two “strong” predictors are high risk with a greater than 50 % chance of choledocholithiasis and should proceed to ERCP. Patients without any predictors may not require any further workup as they have less than 10 % probability of choledocholithiasis. Patients with an intermediate likelihood are those with a combination of predictors that do not meet the high-risk category. Further evaluation prior to ERCP for this group of patients may be reasonable. Specifically, this represents a group of patients that would benefit from further evaluation with endoscopic ultrasound (EUS) or magnetic resonance cholangiopancreatography (MRCP) [2].

In this case our patient demonstrated a “very strong” predictor with a bilirubin greater than 4 mg/dL, a “strong” predictor with a CBD > 6 mm on ultrasonography and a “moderate” predictor with acute pancreatitis in the setting of cholelithiasis. He was identified as high probability for choledocholithiasis and the next step of management was ERCP. EUS or MRCP would not provide any additional useful information and would only delay definitive therapy along with adding additional costs for the patient.

At the time of biliary endoscopy, the lower third of the main bile duct contained multiple stones, the largest of which was 12 × 10 mm in size. The CBD was dilated to 12 mm on cholangiogram as well. Stones were extracted with endoscopic biliary sphincterotomy and balloon sweep (Video 11.1).

A 55-year-old female presents to the emergency room with unrelenting abdominal pain after an evening meal. The patient underwent a cholecystectomy for symptomatic cholelithiasis approximately 1 year prior to her presentation to the emergency department. She reports subsequent intermittent, self-limited episodes of right upper quadrant abdominal pain associated with nausea, emesis, and diaphoresis. An outpatient upper endoscopy was negative. She reports consumption of alcohol at a level of 2–3 drinks per day, 4 days per week. On admission the patient’s lipase is elevated at 2130, her liver function panel reveals an AST of 140, ALT of 250, and total bilirubin is 1.5. A right upper quadrant ultrasound demonstrated an extrahepatic CBD measuring 8 mm in maximal diameter and no evidence for choledocholithiasis. On admission she is afebrile, vital signs are stable. The patient does not have evidence of organ failure or systemic inflammatory response syndrome. In the days following her admission and following conservative management, her pain improves to the point that she requests a diet. However, on admission day 3 her liver function transaminases remain elevated at AST 124, ALT 180 and her total bilirubin is 1.8. She experiences an episode of similar pain when she attempts oral intake.

Questions:

A 42-year-old female presents with acute cholecystitis, suspected NASH cirrhosis, and has a short history of recurrent episodic biliary pancreatitis. The patient presents to the hospital with right upper quadrant and epigastric pain. Her lipase is 434, WBC 12,500, hemoglobin 9.8, and platelet count 68,000. Her bilirubin is elevated to 3.8 with elevated transaminases in the 200 s and elevated alkaline phosphatase of 450. Her international normalized ratio (INR) is also high at 3.26. She undergoes a computed tomography (CT) scan which reveals a distended gallbladder with mild gallbladder wall thickening, and adjacent hepatic hyperemia suggestive of acute cholecystitis. A transabdominal ultrasound scan is then performed which reveals a distended gallbladder and thickened wall without gallstones. Her extrahepatic bile duct measures 7 mm. There are several prominent vessels running along the gallbladder wall. Her vital signs on presentation to the emergency department were temperature 36.8, pulse 112, respiratory rate 18, and blood pressure 102/67. Her oxygen saturations were 100 % on 4 L of oxygen. She was started on IV fluids and broad spectrum antibiotics and transferred to the medical intensive care unit (MICU).

Questions:

The incidence of cholelithiasis in patients after Roux-en-Y gastric bypass (RYGB) varies widely; however, in the literature it has been reported to be as high as 30–50 % [27, 28]. Prophylactic cholecystectomy in patients undergoing bariatric surgery is not currently recommended unless patients are symptomatic prior to or at the time of surgery. Prophylactic cholecystectomy has failed to demonstrate a clear benefit in patients undergoing bariatric surgery, and complications due to gallstone disease post bariatric surgery is limited [29]. Since prophylactic cholecystectomy is not performed routinely at the time of bariatric surgery, managing biliary pancreatitis in post-RYGB surgical anatomy can be complex and will remain an issue faced by many institutions [30].

Endoscopic procedures in patients with RYGB anatomy can be challenging. ERCP in these patients has been performed utilizing a multitude of techniques . These techniques fall into two broad categories that utilize either enteroscopy or laparoscopic-assisted access through the gastric remnant to reach the papilla. However, limitations to the enteroscopy-assisted technique include failure to complete the procedure to the point of desired biliary intervention (as high as 30–40 %), thus requiring surgical/endoscopic access to the gastric remnant, and long procedure times for both modalities. Percutaneous access to the gastric remnant also has the late complications such as persistent gastrocutaneous fistula, and the complexity of coordinating patient care across endoscopic and surgical teams for a single intervention [31–33]. In the setting of patients with suspected biliary pancreatitis and RYGB anatomy, it is imperative that there is proof of biliary obstruction before embarking on combined surgical/endoscopic procedure to perform ERCP or enteroscopy-assisted ERCP.