Intraductal ultrasonographic anatomy of biliary varices in patients with portal hypertension

Diagnosis and management of ectopic varices in portal hypertension

Ectopic variceal bleeding is a rare cause of gastrointestinal bleeding that can occur in settings of cirrhotic and non-cirrhotic portal hypertension and is characterised by its development at locations remote from the oesophagus and stomach. Ectopic varices can be difficult to identify and access, and, although a relatively uncommon cause of portal hypertensive bleeding, can represent a difficult diagnostic and therapeutic challenge associated with considerable mortality. Low incidence and variance in variceal anatomy preclude large randomised controlled trials, and clinical practice is based on experience from case reports, case series, and specialist centre expertise. Optimisation of survival outcomes relies on understanding a patient's portal venous anatomy and functional hepatic reserve to guide timely and targeted endoscopic and endovascular interventions to facilitate the rapid control of ectopic variceal bleeding.

An Uncommon Cause of Biliary Obstruction in a Patient With Budd-Chiari Syndrome

Biliary varices (BVs) are an infrequent complication of chronic portal hypertension. Most cases of BVs are asymptomatic and are likely underdiagnosed. We present a case of a 34-year-old woman with Budd-Chiari syndrome who was found to have BVs caused by a significant inferior vena cava (IVC) stenosis. This case demonstrates that preprocedure imaging for variceal screening should be considered before biliary tract procedures to prevent complications.

Structure and Distribution of an Unrecognized Interstitium in Human Tissues

Confocal laser endomicroscopy (pCLE) provides real-time histologic imaging of human tissues at a depth of 60-70 μm during endoscopy. pCLE of the extrahepatic bile duct after fluorescein injection demonstrated a reticular pattern within fluorescein-filled sinuses that had no known anatomical correlate. Freezing biopsy tissue before fixation preserved the anatomy of this structure, demonstrating that it is part of the submucosa and a previously unappreciated fluid-filled interstitial space, draining to lymph nodes and supported by a complex network of thick collagen bundles. These bundles are intermittently lined on one side by fibroblast-like cells that stain with endothelial markers and vimentin, although there is a highly unusual and extensive unlined interface between the matrix proteins of the bundles and the surrounding fluid. We observed similar structures in numerous tissues that are subject to intermittent or rhythmic compression, including the submucosae of the entire gastrointestinal tract and urinary bladder, the dermis, the peri-bronchial and peri-arterial soft tissues, and fascia. These anatomic structures may be important in cancer metastasis, edema, fibrosis, and mechanical functioning of many or all tissues and organs. In sum, we describe the anatomy and histology of a previously unrecognized, though widespread, macroscopic, fluid-filled space within and between tissues, a novel expansion and specification of the concept of the human interstitium.

Portal biliopathy

Portal biliopathy refers to cholangiographic abnormalities which occur in patients with portal cavernoma. These changes occur as a result of pressure on bile ducts from bridging tortuous paracholedochal, epicholedochal and cholecystic veins. Bile duct ischemia may occur due prolonged venous pressure effect or result from insufficient blood supply. In addition, encasement of ducts may occur due fibrotic cavernoma. Majority of patients are asymptomatic. Portal biliopathy is a progressive disease and patients who have long standing disease and more severe bile duct abnormalities present with recurrent episodes of biliary pain, cholangitis and cholestasis. Serum chemistry, ultrasound with color Doppler imaging, magnetic resonance imaging with magnetic resonance cholangiopancreatography and magnetic resonance portovenography are modalities of choice for evaluation of portal biliopathy. Endoscopic retrograde cholangiography being an invasive procedure is indicated for endotherapy only. Management of portal biliopathy is done in a stepwise manner. First, endotherapy is done for dilation of biliary strictures, placement of biliary stents to facilitate drainage and removal of bile duct calculi. Next portal venous pressure is reduced by formation of surgical porto-systemic shunt or transjugular intrahepatic portosystemic shunt. This causes significant resolution of biliary changes. Patients who persist with biliary symptoms and bile duct changes may benefit from surgical biliary drainage procedures (hepaticojejunostomy or choledechoduodenostomy).

Intraductal Sonography in Patients With Portal Cavernoma Cholangiopathy

Intraductal sonography generates high-resolution images of the entire length of the biliary tree and peribiliary tissues, including 3-dimensional dual- and muti-plane reconstructions to depict complex anatomy. Portal cavernoma cholangiopathy (previously called portal biliopathy) can have multiple etiologies of obstructive cholestasis in the same patient, which can be difficult to define even with advanced imaging techniques.We describe 2 difficult cases of portal cavernoma cholangiopathy in which intraductal sonography helped in clinical management decisions. We think that intraductal sonography should be part of the standard management algorithm for patients with portal cavernoma cholangiopathy and describe the intraductal sonographic correlates of the cholangiographic changes in this condition.

Endoscopic ultrasonography-guided placement of a transhepatic portal vein stent in a live porcine model

Background and Objectives:

Percutaneous portal vein (PV) stent placement is used to manage PV occlusion or stenosis caused by malignancy. The use of endoscopic ultrasonography (EUS) has expanded to include vascular interventions. The aim of this study was to examine the technical feasibility and safety of EUS-guided transhepatic PV stent placement in a live porcine model.

Materials and Methods:

EUS-guided transhepatic PV stent placement was performed in six male miniature pigs under general anesthesia using forward-viewing echoendoscope. Under EUS guidance, the left intrahepatic PV was punctured with a 19-gauge fine-needle aspiration (FNA) needle and a 0.025 inch guidewire inserted through the needle and into the main PV. The FNA needle was then withdrawn and a needle-knife inserted to dilate the tract. Under EUS and fluoroscopic guidance, a noncovered metal stent was inserted over the guidewire and released into the main PV.

Results:

A PV stent was placed successfully in all six pigs with no technical problems or complications. The patency of the stent in the main PV was confirmed using color Doppler EUS and transhepatic portal venography. Necropsy of the first three animals revealed no evidence of bleeding and damage to intra-abdominal organs or vessels. No complications occurred in the remaining three animals during the 8 weeks observation period.

Conclusions:

EUS-guided transhepatic PV stent placement can be both technically feasible and safe in a live animal model.

The role of intraductal ultrasonography in pancreatobiliary diseases

Intraductal ultrasonography (IDUS) provides real-time, cross-sectional imaging of pancreatobiliary ducts and surrounding structures during endoscopic retrograde cholangiopancreatography using a high-frequency ultrasound (US) transducer. Hence, IDUS has been considered a sensitive tool in the evaluation of suspicious choledocholithiasis and neoplasms, to help distinguish between benign and malignant bile duct strictures or wall thickness, and to assess tumor extension and invasion depth. With the rapid development and enriched choices of sensitive diagnostic modalities include but are not limited to endoscopic US, peroral cholangioscopy, and confocal laser endomicroscopy, it is needed to systematically assess the role of IDUS in the investigation of pancreatobiliary diseases. Some new developments and innovative use of IDUS techniques will be discussed in this paper with the review of literature.