Biliary intervention – Percutaneous vs. ERCP vs. EUS guidance

A biliary stricture (BS) is a narrowing of the biliary tree caused by benign or malignant conditions. Differential diagnosis between the different forms of BS can be challenging, as the etiology may remain indeterminate even after carrying out complete laboratory, imaging, and tissue-based diagnostic investigations. Despite improvements in endoscopic techniques and a greater knowledge of the underlying causes of the condition acquired over the last decade, about 15%-20% of patients with indeterminate BS undergoing surgery are found to have a benign disease, with high postoperative mortality (10%) reported in many Western referral centers. Patients with indeterminate BS or a diagnosis of indeterminate dysplasia at histopathological evaluation require a multidisciplinary approach involving gastroenterologists, surgeons, radiologists, and oncologists for diagnosis and appropriate treatment.

Endoscopic transpapillary biliary drainage (BD) is the preferred approach for biliary decompression in patients with unresectable pancreatic cancer and obstructive jaundice. Percutaneous transhepatic cholangiography (PTC) is a diagnostic and therapeutic procedure that involves inserting a needle into the biliary tree, followed by immediately inserting a catheter to achieve percutaneous BD. During the procedure, contrast is injected into one or more bile ducts (cholangiography) and sometimes into the duodenum. PTC can be performed using fluoroscopic guidance alone or using both fluoroscopic and ultrasound guidance. In cases of suspected malignant biliary stricture, imaging alone may not be sufficient to provide a precise diagnosis.

PTC was first introduced several decades ago to visualize biliary obstructions, treat malignant obstructive jaundice palliatively, and access BD. Fine needle aspiration (FNA), brush cytology, and forceps biopsy have been performed using percutaneous biliary catheterization during PTC since the 1980s. For biliary stenosis, endoscopic retrograde cholangiopancreatography (ERCP) has recently been recognized as a reliable diagnostic and therapeutic procedure. Endoscopic retrograde BD (ERBD) is the most commonly used method of biliary decompression in patients with blockage of the distal central bile duct. This technique has a success rate of 90%-95%. Altered anatomy, presenting pathology (tumor infiltration, impacted stone, and duodenal compression by a pancreatic pseudocyst), previous surgery, or variations in normal anatomy (periampullary diverticula and tortuous ducts) can contribute to the failure of ERBD.

The failure rate of ERBD is 6%-7% in cases with obstructive jaundice caused by a blockage or altered anatomy. Percutaneous transhepatic BD (PTBD) has a lower risk of complications than surgical decompression, but it is associated with some complications and the requirement for long-term external catheter drainage, which contribute to a low quality of life. The only relative contraindication of PTBD is perihepatic ascites. Furthermore, PTBD usually requires separate surgery after the failure of ERCP BD, thereby increasing the morbidity associated with biliary stasis.

Endoscopic ultrasound-guided BD (EUS-BD) has become more widely used as an alternative to PTBD in patients with anatomical abnormalities, which make endoscopic transpapillary insertion of a biliary stent difficult. It offers the advantages of being compatible with anatomic internal drainage, being more comfortable, and a recovery associated with fewer complications and reduced expenditure. EUS is an extremely useful imaging method for examining the gastrointestinal luminal wall and surrounding tissues. The proximity of the EUS probe to the area of interest enables high-resolution imaging and EUS-guided FNA tissue collection in real time. EUS has become a crucial diagnostic technique due to its high-quality imaging and FNA capacity and is also used as a treatment tool. However, until recently, its use was limited to the introduction of various drugs.

The therapeutic uses of EUS have been expanded due to larger channel echoendoscopes, which combine the benefits of real-time ultrasound and fluoroscopy imaging with the use of ERCP-based devices and procedures, such as EUS-BD. Few studies have compared EUS-BD and PTBD in failed ERCP cases in terms of success rate and adverse event profile. Therefore, it is necessary to analyse relevant literature to investigate the combined efficacy and adverse effects of PTBD, ERCP and EUS-BD.