The aim of this clinical trial is to evaluate temporal delay (days) between biliary drainage (EUS-CDS vs ERCP as first line therapy) and chemotherapy start in patients with borderline distal malignant biliary obstruction.

Ecoendoscopy-guided choledochoduodenostomy (EUS-CDS) has been extended as a second line treatment in cases of ERCP failure in malignant distal biliary obstruction (MDBO). However, there are clinical trials which have compared it with ERCP as a first line treatment for MDBO in palliative patients, showing similar clinical and technical success and adverse events (AEs) rate between both techniques. Data about the benefit of this techique in borderline patients is still limited.

A recent retrospective study (Janet J et al, Ann Surg Oncol 2023) which included borderline patients, found that EUS-CDS group had significantly less delay (days) between biliary drainage and neoadjuvant chemotherapy start than the ERCP group with fewer endoscopy and surgery AEs.

Thus, our hypothesis is that EUS-CDS has benefits in terms of decreasing delay between biliary drainage and neoadjuvant chemotherapy start when compared to ERCP in MDBO in borderline patients.

Inclusion Criteria:

• Malignant distal biliary obstruction diagnosed in patient considered BORDERLINE with biliary drainage indication: i) impaired hepatic enzymes (including hyperbilirubinemia) x3 times upper the superior normal value. ii) Radiologic singns of extrahepatic bile duct obstruction with presence of retrograde dilatation, of at least 12-mm axial diameter.
• Consensual malignancy by a bilio-pancreatic multidisciplinar committe (histological confirmation is not mandatory)
• Patient capable of understanding and/or singning the informed consent.
• Patient who understands the type of study and will comply with all follow-up tests throughout its duration

Exclusion Criteria:

• Pregnancy or lactation.
• Severe coagulation disorder: INR > 1.5 non correctable with plasma administration and/or platelet count < 50.000/mm3.
• Distal malignant biliary strictures in patients considered directly resectable, non-surgical, unresectable, or palliative
• Benign or uncertain etiology of biliary strictures or strictures located proximally or in close proximity to the hilum.
• Patients with prior biliary stents or other biliary drainages (e.g., PTCD).
• Altered intestinal anatomy due to prior surgery that prevents or hinders papillary access (e.g., gastric bypass, Billroth II, duodenal switch, Roux-en-Y).
• Stenosis in the antral or duodenal region that prevents access to the duodenum and reaching the papilla.
• Situations that do not allow for upper gastrointestinal endoscopy (e.g., esophageal stricture).
• Patients with functional diversity, who lack the capacity to understand the nature and potential consequences of the study, except when a legal representative is available.
• Patients incapable of maintaining follow-up appointments (lack of adherence).
• Lack of informed consent.