Stones in the bile duct: Minimally invasive surgical approaches

Epidemiology of choledocholithiasis

The prevalence of cholelithiasis is approximately 15% in the general population, with up to 10% of patients having concomitant choledocholithiasis (CDL; for more information, see Chapter 33 ). The prevalence of gallstones is increased in the elderly population over 65 years of age, reaching up to 35% in women. Risk factors for gallstones include: obesity, type 2 diabetes and insulin resistance, genetic defects in cholesterol metabolism, female gender, rapid weight gain or loss (as seen with bariatric surgery and pregnancy), systemic inflammatory diseases (such as Crohn disease and rheumatoid arthritis ), hemolytic disorders, and conditions leading to biliary stasis (cystic fibrosis, chronic total parenteral nutrition [TPN], estrogen hormonal supplementation). The majority of common bile duct (CBD) stones in Western countries are secondary to gallstone formation within the gallbladder, with an extraordinarily higher prevalence in Native American (73%) and Hispanic (27%) populations. In Eastern countries, the incidence of primary hepatolithiasis and CDL is higher (see Chapter 39 ), with reported prevalence ranging from 2% to 25%, related to endemic infectious organisms that colonize the liver and biliary tree (e.g., Clonorchis sinensis , liver fluke; see Chapter 45 ) and cause a predisposition to recurrent pyogenic cholangitis ^, (see Chapter 44 ).

CDL is identified in up to 18% of patients undergoing cholecystectomy. Additionally, some patients may be asymptomatic with intra- and extrahepatic biliary dilation and/or CBD stones incidentally identified on cross-sectional imaging performed for other clinical indications. These clinical scenarios can vary significantly in presentation and morbidity, ranging from minimal symptoms to critical illness caused by septic cholangitis. If left untreated, chronic CDL can also cause inflammatory strictures, recurrent infections, or biliary cirrhosis.

Clinical presentation

The index of suspicion for the presence of CBD stones should be high in patients presenting with gallstone pancreatitis (see Chapters 54 and 55 ), ascending cholangitis (see Chapter 43 ), or obstructive jaundice in the setting of acute or chronic cholecystitis with a history of biliary colic (see Chapter 34 ). Hyperbilirubinemia, defined as elevation of the total bilirubin level greater than 1.3 mg/dL with a predominant unconjugated (direct) component, is most suggestive of biliary obstruction in a patient with otherwise no evidence or history of underlying liver disease (see Chapter 4 ). Elevation of the alkaline phosphatase (AP) levels (>150 IU/L) out of proportion to changes in the aminotransferase enzyme levels can be seen in the presence of nonobstructing stones or sludge, and an upward trend can be indicative of ongoing cholestasis and/or inflammation of the biliary tree. Elevated gamma-glutamyl transferase levels (>50 IU/L) can confirm a hepatobiliary source of the elevated AP in complex or asymptomatic patients.

Depending on the clinical presentation, first-line imaging modalities include abdominal ultrasound (most sensitive test for identifying gallstones and ductal dilation) and/or single phase abdominal CT scan (most sensitive for identifying acute cholecystitis). ^, Intra- or extrahepatic biliary dilation, dilation of the CBD more than 8 mm, or the presence of a filling defect can be informative and guide the treatment algorithm. The caliber, number, and location of the stones combined with the clinical status of the patient will also influence treatment decisions (see Chapter 13 ).

In patients where the diagnosis of CDL is unclear, either magnetic resonance cholangiopancreatography (MRCP; see Chapter 13 ) or endoscopic ultrasound (EUS; see Chapter 22 ) with or without endoscopic retrograde cholangiopancreatography (ERCP; see Chapter 20 ) can be considered. Recent meta-analyses demonstrate that both EUS and MRCP have high specificity for identifying CDL, with a slightly higher sensitivity for EUS and the added therapeutic benefit of performing ERCP if stones are identified. MRCP can be useful when ERCP is not available and may provide anatomic delineation before surgery. Some centers advocate MRCP to avoid the risk of unnecessary ERCP; however, this is associated with an increased cost. The choice of modality may depend on clinical factors of the patient. For example, a patient with a history of Roux-en-Y gastric bypass (RNYGB) surgery complicates the ability to perform routine EUS/ERCP without the use of single or double balloon enteroscopy via the Roux limb. In contrast, a patient with a pacemaker, severe claustrophobia, or inability to hold their breath may preclude MRCP as an option in the diagnostic work-up.

Historical management of choledocholithiasis

The management of CDL has evolved dramatically over the last four decades (see Chapter 38 ). Before the advent of laparoscopy in the 1980s, stones in the CBD were identified and removed at the time of open surgical exploration for cholecystectomy. Even after the introduction of ERCP in the 1970s, laparotomy remained the mainstay for CBD exploration (CBDE; see Chapter 37A ). At that time, the tools and techniques used for surgical clearance of the CBD were superior to those available via ERCP, and as long as a laparotomy was used to perform the cholecystectomy, minimally invasive treatment of CDL was unnecessary. It was not until the introduction of the laparoscopic cholecystectomy (LC) in the late 1980s that finding an associated less invasive method of treating CDL became a priority.

During the initial adoption of LC, most general surgeons did not have the skill set, experience, or equipment to facilitate a laparoscopic CBDE. As the skills, experience, and tools have developed, the advantages and disadvantages of laparoscopic CBDE versus ERCP have been a frequent source of debate (see Chapter 37C ).

This chapter will discuss laparoscopic techniques for managing CDL, including indications and technical aspects of laparoscopic transcystic, transcholedochal, and transduodenal CBDE, as well as laparoscopic biliary-enteric bypass procedures and laparoscopic-assisted ERCP.

Indications for intervention

The standard of care for the management of most CBD stones is minimally invasive, whether laparoscopic, endoscopic, or percutaneous. The minimally invasive techniques used and the sequence in which they are used depends on the specific clinical scenario. In addition, the capability and experience of the available personnel at each institution will affect the treatment algorithm. The most common clinical scenarios encountered by surgeons include known or suspected stones before cholecystectomy, the diagnosis of stones intraoperatively, and stones identified subsequent to cholecystectomy.