Amit Pathak

Perforators of common bile duct wall in portal hypertensive biliopathy (with videos)

Extrahepatic obstruction of the portal vein (EHPVO) with resulting portal hypertension may cause extensive collateral venous circulation at the porta hepatis. Portal hypertensive biliopathy (PHB) refers to abnormalities of the biliary tract in patients due to these portoportal collaterals. 1,2 These collateral veins are related to 2 preformed venous systems near the extrahepatic bile ducts: the paracholedochal (PACD) veins of Petren, and the epicholedochal (ECD) venous plexus of Saint. The PACD venous plexus of Petren runs parallel to the CBD, and the ECD plexus of Saint veins form a reticular mesh on the surface of the CBD. 3,4 The PACD collaterals, if dilated, may cause extrinsic compression and protrusion into the thin and pliable CBD, and the ECD collaterals, if dilated, may make the normallysmoothintraluminalsurfaceoftheCBDirregular. 5,6 Detection of these dilated venous collateral vessels is important for making the diagnosis of PHB. Detection of large PACD and ECD collaterals has been done by color Doppler US (CDUS). 7 Smaller collaterals are identified by EUS, color Doppler EUS (CD-EUS), and intraductal EUS. 8-10 On magnetic resonance imaging, PACD collaterals and ECD collaterals are identified separately. 11,12

Endoscopic ultrasound imaging of pancreatic duct ascariasis

Ascaris lumbricoides infestation is endemic in tropical countries. Most infections by A. lumbricoides are asymptomatic, but they can produce a wide spectrum of manifestations including hepatobiliary and pancreatic complications. Pancreatic ascariasis is a rare entity. In a study of 500 patients with hepatobiliary and pancreatic disease due to A. lumbricoides infection, only seven had pancreatic ascariasis [1], and there are few case reports of ascariasis-induced acute pancreatitis [2]. Mechanisms of acute pancreatitis associated with ascariasis include invasion of the pancreatic duct, the ampullary orifice, and both the common bile duct and the pancreatic duct [3]. Idiopathic pancreatitis is diagnosed when clinical, laboratory, and conventional radiologic methods do not provide a clear etiology for the episode. In the past, endoscopic retrograde cholangiopancreatography (ERCP) has been the imaging test of choice for evaluation of idiopathic recurrent acute pancreatitis, whereas now endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreaFig.1 Endoscopic ultrasonography (EUS) was done for investigation of idiopathic recurrent acute pancreatitis in a 30-year-old man. a A linear echogenic shadow was seen in the pancreatic duct within the head of the pancreas. b EUS from the duodenal bulb demonstrated the ascaris worm in the head of the pancreas. c EUS from the descending duodenum showed a linear shadow with two hyperechoic linear echogenic strips on either side of the longitudinal anechoic lumen of the ascaris worm. Fig.2 Side-viewing endoscopy showed two ascaris worms in the duodenal lumen; one was extruding from the papilla. They were removed with biopsy forceps.

Imaging of pancreas divisum by linear-array endoscopic ultrasonography.

Pancreas divisum (PD) is the most common developmental anatomic variant of pancreatic duct. Endoscopic ultrasound (EUS) is often performed to evaluate idiopathic pancreatitis and has been shown to have high accuracy in diagnosis of PD. The different techniques to identify PD by linear EUS have been described differently by different authors. If EUS is done with a proper technique it can be a valuable tool in the diagnosis of PD. The anatomical and technical background of different signs has not been described so far. This article summarizes the different techniques of imaging of pancreatic duct in a suspected case of PD and gives a technical explanation of various signs. The common signs seen during evaluation of pancreatic duct in PD are stack sign of linear EUS, crossed duct sign on linear EUS, the dominant duct and ventral dorsal duct (VD) transition. Few other signs are described which include duct above duct, short ventral duct /absent ventral duct, separate opening of ducts with no communication, separate opening of ducts with filamentous communication, stacking of duct of Santorini and indirect signs like santorinecele. The principles of the sign have been explained on an anatomical basis and the techniques and the principles described in the review will be helpful in technical evaluation of PD during EUS.

Seagulls of endoscopic ultrasound

The analogical description of a shape may be helpful in better understanding of anatomical structures during imaging. Seagull is a popular name for a seabird with a heavy body and two long wings. The “seagull sign ”has been used in cardiology for evaluation of the mitral valve and in orthopedics for erosive osteoarthritis.[1-3] On a plain X-ray abdomen, a triradiate collection of a dark shadow of nitrogen gas within gallstone creates a “seagull sign”.[4]

Imaging of common bile duct by linear endoscopic ultrasound

Imaging of common bile duct (CBD) can be done by many techniques. Endoscopic retrograde cholangiopancreaticography is considered the gold standard for imaging of CBD. A standard technique of imaging of CBD by endoscopic ultrasound (EUS) has not been specifically described. The available descriptions mention different stations of imaging from the stomach and duodenum. The CBD lies closest to duodenum and choice of imaging may be restricted to duodenum for many operators. Generally most operators prefer multi station imaging during EUS and the choice of selecting the initial station varies from operator to operator. Detailed evaluation of CBD is frequently the main focus of imaging during EUS and in such situations multi station imaging with a high-resolution ultrasound scanner may provide useful information. Examination of the CBD is one of the primary indications for doing an EUS and it can be done from five stations: (1) the fundus of stomach; (2) body of stomach; (3) duodenal bulb; (4) descending duodenum; and (5) antrum. Following down the upper 1/3(rd) of CBD can do imaging of entire CBD from the liver window and following up the lower 1/3(rd) of CBD can do imaging of entire CBD from the pancreatic window. This article aims at simplifying the techniques of imaging of CBD by linear EUS.

EUS imaging of dead Ascaris

Figure 2. Linear EUS view showing rounded hyperechoic structure in dilated common bile duct. CBD, common bile duct. A 4-year-old Indian boy presented because of recurrent biliary colic and jaundice for the previous 2 weeks. There was no history of fever. Laboratory investigations revealed alanine aminotransferase, 156 U/L (normal, 0-30 U/L); aspartate aminotransferase, 204 U/L (normal, 0-30 U/L); serum alkaline phosphatase, 920 U/L (normal, 30-120 U/L); and serum bilirubin, 8.4 mg/dL (normal, 0.2-1.2 mg/dL). Abdominal US revealed a normal gallbladder, dilation of the intrahepatic biliary radicles, and a dilated common bile duct (CBD) of 14 mm, with an ill-defined rounded echogenic shadow inside the lower end of the CBD. The possible differential diagnoses of CBD polyp, choledochal cyst with sludge, CBD stone, and a dead coiled worm were considered. EUS was performed with a linear echoendoscope (Pentax EG 3830 UT; Pentax, Tokyo, Japan) by use of a Hitachi Avius processor (Hitachi, Tokyo, Japan) before ERCP to determine the cause of the dilated CBD and further characterize the echogenic shadow seen on US. Linear EUS from the stomach revealed dilatation of the CBD to 14 mm, with a rounded hyperechoic structure without acoustic shadowing in the lower CBD (Figs. 1 and 2; Video 1, available online at www.VideoGIE.org). Linear EUS from the duodenal bulb with color Doppler imaging showed a hyperechoic avascular structure with a central anechoic area inside the CBD (Figs. 3 and 4; Video 1). This structure was without acoustic shadow,

Biliary ascariasis: mimicker of biliary stent

Figure 2. US view of abdomen showing Ascaris lumbricoides mimicking stent within dilated common bile duct. A 50-year-old-man presented because of yellowish discoloration of the eyes, right upper-quadrant pain, and high-grade fever for 3 days. He had a history of common bile duct (CBD) stones and gallstones. He had undergone multiple ERCP procedures and biliary sphincterotomy with removal of stones and plastic biliary stent placement 1 year previously. Laboratory examination showed the following: white blood cell count of 20,000/mm with 88% neutrophils, aspartate transaminase 230 U/L (reference 0-32 U/L), alanine transaminase 380 U/L (reference 0-32 U/L), alkaline phosphatase 470 U/L (reference 0-120 U/L), and bilirubin 5 mg/dL (reference 0-2 mg/dL). A clinical diagnosis of acute cholangitis was established. Abdominal US showed dilation of intrahepatic biliary radicles, hepatomegaly, and dilated CBD (11 mm) with a linear echogenic structure (Figs. 1 and 2; Video 1, available online at www.VideoGIE.org). A possibility of cholangitis resulting from stent occlusion was considered. ERCP was planned for removal of the stent and clearance of the CBD. On ERCP, the papilla was patulous, with no stent in situ. The possibility of a migrated CBD stent was considered. A cholangiogram revealed dilated CBD with a linear echogenic filling structure inside the CBD, suggestive of Ascaris lumbricoides rather than a stent (Figs. 3 and 4). The CBD was cannulated with a stone extraction balloon (Fig. 5). A balloon sweep was performed, and a live creamy-white worm was removed from the papilla (Fig. 6). The worm was grasped with rat-tooth forceps (Fig. 7) and identified as A lumbricoides. The patient underwent therapy with albendazole and passed multiple roundworms in his stool. Repeated US after 2 weeks showed the CBD to be normal. To conclude, we present a case of cholangitis due to biliary ascariasis mimicking biliary stent on US. Biliary ascariasis should be considered in a patient presenting with acute cholangitis in endemic regions. A lumbricoides is the most common helminthic infection in the world. Although the duodenum and proximal jejunum are the normal habitats of an adult worm, occasionally these worms migrate to the CBD, the pancreatic duct (PD), or the gallbladder, leading to adverse events like biliary colic, cholecystitis, acute cholangitis, and pancreatitis. Biliary ascariasis is a common cause of pancreatobiliary disease in an endemic region. Migration of a worm to the CBD is more common than to the PD,

Endoscopic ultrasound of peritoneal spaces

The peritoneal cavity is subdivided into supracolic and infracolic compartments by transverse colon and its mesocolon. The supracolic compartment contains the liver, spleen, stomach, and lesser omentum. The infracolic compartment contains the coils of small bowel surrounded by ascending, transverse, and descending colon and the paracolic gutters. The imaging of different compartments is possible by various methods such as ultrasound (US) and computerized tomography. The treating physicians should be familiar with the relevant radiological anatomy of different compartments and spaces as accurate localization of fluid collection/lymph node in peritoneal cavity greatly aids in selection of a treatment strategy. The role of endoscopic US (EUS) is emerging for detail evaluation of all parts of peritoneal cavity as it provides an easy access for fine-needle aspiration from different compartments of peritoneal cavity. In this review, we describe the techniques of evaluation of different parts of supracolic compartments of peritoneum by EUS.

Endoscopic ultrasound of bile duct ascariasis (with video)

A 40‐year‐old male with no significant medical history was admitted to the hospital with yellowish discoloration of eyes, mild right upper quadrant pain, and intermittent fever for last 1 week. Physical examination revealed icterus and hepatomegaly. Laboratory examination showed obstructive jaundice (aspartate transaminase‐230 U/L, alanine transaminase-180 U/L, alkaline phosphatase-370 U/L, and billirubin-3 mg/dL). Ultrasonography abdomen (USG) revealed dilated common bile duct (CBD) (9 mm) with ill‐defined echogenic shadows. Endoscopic ultrasonography (EUS) was performed with a linear echoendoscope (Pentax EG 3830 UT) using Hitachi Avius‐processor at 7.5 MHz frequency for evaluation of echogenic shadow. It revealed linear echogenic mobile shadow coiling in CBD confirming the diagnosis of biliary ascariasis. This linear shadow had two hyperechoic linear echogenic strips on either side of the longitudinal anechoic lumen of the Ascaris [Video 1 and Figure 1]. On side-viewing endoscopy, the worm was visualized partially lying outside the papilla. The worm was extracted with biopsy forceps and identified as Ascaris lumbricoides [Video 1 and Figure 2]. The worm was 9 cm long and creamy white. Subsequently, deworming was done with albendazole. On follow-up visit, the patient was asymptomatic and USG revealed normal CBD. Biliary ascariasis is a common problem in tropical countries. Abdominal USG, which is the first modality for evaluation of such patients, can allow biliary ascariasis to be diagnosed in 85% of cases. The characteristic sonographic features of worms in the CBD are multiple, long, linear, parallel echogenic strips, usually without acoustic shadowing.[1] Both EUS and magnetic resonance cholangiopancreatography are used for evaluation of dilated CBD. However, EUS appears to be an investigation of choice for dilated CBD.[2,3] On EUS, A. lumbricoides appears as long echogenic structure with central anechoic linear defect, without producing shadow effect. It appears as linear echogenic shadow with two hyperechoic linear echogenic strips on either side of the longitudinal anechoic lumen.[4] Endoscopic intervention has become the treatment of choice. Worms visible at the ampulla can be extracted endoscopically with dormia basket or biopsy forceps. Endoscopic retrograde cholangiopancreatography should be performed if a roundworm has migrated or is present inside the bile duct. Sphincterotomy should be avoided for worm extraction because an open biliary sphinctercan lead to recurrence if worm reinfestation occurs.[5]

Blind areas of cardiac imaging during transesophageal echocardiogram/endoscopic ultrasound

352 Dear Editor, Transoesophageal echocardiography (TEE) allows imaging of unparalleled quality because of the proximity of esophagus to cardiac structures without interposition of pulmonary or parietal structures.[1] The main indications for TEE include acute aortic endocarditis, thromboembolic accidents, cryptogenic stroke, and valvular heart disease.[1] TEE also plays an invaluable role in diagnosing and monitoring the patient’s hemodynamics during cardiac and noncardiac surgery.[2] Guidelines for performing a Letter to Editor