Biliary obstruction was accomplished by surgically occluding the distal common bile duct in seven rhesus monkeys. Ultrasound scanning at 24-hour intervals showed that dilation of the common bile duct and gallbladder occurred before elevation of bilirubin or development of jaundice. The bile ducts expanded centrifugally from the obstructing point, with dilation of the intrahepatic ducts occurring several days after the onset of obstruction. After surgical release of the obstruction, the biliary ducts contracted centripetally, with the common bile duct requiring 30-50 days to return to normal size.
Abbreviations: MDBO, malignant distal biliary obstruction; CT, computed tomography; MRI, magnetic resonance imaging; TUS, transabdominal ultrasound; EUS, endoscopic ultrasound; FNA, fine-needle aspiration; FNB, fine-needle biopsy; PSC, primary sclerosing cholangitis; NET, neuroendocrine tumors.
Malignant biliary obstruction is a challenging condition, requiring a multimodal approach for both diagnosis and treatment. Pancreatic adenocarcinoma and cholangiocarcinoma are the leading causes of malignant distal biliary obstruction. Early diagnosis is difficult to establish as biliary obstruction can be the first presentation of the underlying disease, which can already be at an advanced stage. Consequently, the majority of patients (70%) with malignant distal biliary obstruction are unresectable at the time of diagnosis. The association of clinical findings, laboratory tests, imaging, and endoscopic modalities may help in identifying the underlying cause. Novel endoscopic techniques such as cholangioscopy, intraductal ultrasonography, or confocal laser endomicroscopy have been developed with promising results, but are not used in routine clinical practice. As the number of patients with malignant distal biliary obstruction who will undergo curative surgery is limited, endoscopy has a crucial role in palliation, to relieve biliary obstruction. According to the last European guidelines published in the management of biliary obstruction, self-expandable metal stents have a central place in biliary drainage compared to plastic stents. Endoscopic ultrasound has evolved impressively in the last decades. When standard techniques of biliary cannulation by endoscopic retrograde cholangiopancreatography fail, endoscopic ultrasound-guided biliary drainage is a good option compared to percutaneous drainage.
Preoperative biliary drainage (PBD) in patients with MDBO is an area of controversy. Previously studies suggested that hyperbilirubinemia was associated with increased postoperative morbidity and mortality, and therefore advocated PBD.86 Nevertheless, in 2010, a large randomized control trial (RCT) comparing PBD vs no PBD (202 patients with MDBO) reported higher rates of severe complications in patients undergoing PBD (74%vs 39%).87 No improvement in any outcome was observed in the PBD group.87 Of note, in the aforementioned study, the PBD group underwent surgery within 4–6 weeks and one single plastic stent (PS) was used, which could contribute to the high complication rate related to PBD.87 Since then, numerous studies and meta-analysis have been published; the latest meta-analysis including 32 studies with patient with MBDO due to pancreatic cancer, suggested that refraining from PBD could be associated with a better outcome.88 Subsequently, the current guidelines published by the ESGE recommend against routine PBD in patient with extra-hepatic obstruction.89 Well-accepted indications for PBD are cholangitis or intractable pruritus.89 Severe jaundice was also advocated as an indication of biliary drainage: Sauvanet et al have recently published in a retrospective series of 1200 patients a high risk of severe postoperative in patients with severe jaundice (total serum bilirubin >300 μmol/l).90 In controversy, Arkadopoulos et al showed in a retrospective study of 152 patients that even in patients with total serum bilirubin > 256 μmol/l, PBD presented no advantage.91 Of note, patients with total serum bilirubin > 250 μmol/l were excluded from the largest RCT of PBD vs no PBD87 Therefore, the indication of severe jaundice remains unclear. The current guidelines of ESGE also recommend PBD in case of delayed surgery (more 2 weeks), and in patients undergoing neoadjuvant chemotherapy who also benefit PBD to bring liver functions tests to ranges acceptable for chemotherapy and avoid potential hepatotoxic effects of chemotherapeutic drugs ( Figure 5 ).89
Dyspepsia/early satiety → nausea/emesis