Atsushi Irisawa

JSUM ultrasound elastography practice guidelines: pancreas

Ultrasound elastography is a relatively new diagnostic technique for measuring the elasticity (hardness) of tissue. Eleven years have passed since the debut of elastography. Various elastography devices are currently being marketed by manufacturers under different names. Pancreatic elastography can be used not only with transabdominal ultrasonography but also with endoscopic ultrasonography, but some types of elastography are difficult to perform for the pancreas. These guidelines aim to classify the various types of elastography into two major categories depending on the differences in the physical quantity (strain, shear wave), and to present the evidence for pancreatic elastography and how to use pancreatic elastography in the present day. But the number of reports on ultrasound elastography for the pancreas is still small, and there are no reports on some elastography devices for the pancreas. Therefore, these guidelines do not recommend methods of imaging and analysis by elastography device.

Interventional endoscopic ultrasonography

Endoscopic ultrasonography (EUS) is the combination of endoscopy and intraluminal ultrasonography. This allows use of a high frequency transducer, which, due to the short distance to the target lesion, enables ultrasonographic images of high resolution to be obtained. Endoscopic ultrasonography is now a widely accepted modality for the diagnosis of pancreatobiliary diseases. It can be used to determine the depth of invasion of gastrointestinal malignancies, and often for visualizing lesions more precisely than other imaging modalities. The most important early limitation of EUS was the lack of specificity in the differentiation between benign and malignant changes. In 1992, EUS‐guided fine needle aspiration (EUS‐FNA) of lesions in the pancreas head has been made possible using a curved linear array echoendoscope. Since then, many researchers have expanded the indication of EUS‐FNA to various kinds of lesions and also for a variety of therapeutic purposes. In this review, we particularly focus on the present and future roles of interventional EUS, including EUS‐FNA and therapeutic EUS.

Pancreatobiliary drainage using the EUS-FNA technique: EUS-BD and EUS-PD

The recent progression of endoscopic ultrasonography (EUS) enables EUS-guided transmural drainage based on the EUS-guided fine-needle aspiration biopsy technique. Prior to the development of EUS-guided drainage procedures, the options for treating obstruction of the pancreatobiliary system included surgical drainage, percutaneous drainage using ultrasound and radiological guidance, and endoscopic (non EUS-guidance) transmural drainage. Today, using EUS guidance and dedicated accessories, it is possible to create bilio- or pancreato-digestive anastomosis, EUS-guided biliary drainage (EUS-BD), and EUS-guided pancreatic drainage (EUS-PD). The recent literature describes that EUS-BD and EUS-PD have acceptable success and complication rates. These procedures are anticipated for use as alternatives to surgery or percutaneous drainage when endoscopic transpapillary procedures fail.

Guidelines for sedation in gastroenterological endoscopy

Recently, the need for sedation in gastrointestinal endoscopy has been increasing. However, the National Health Insurance Drug Price list in Japan does not include any drug specifically used for the sedation. Although benzodiazepines are the main medication, their use in cases of gastrointestinal endoscopy has not been approved. This has led the Japan Gastrointestinal Endoscopy Society to develop the first set of guidelines for sedation in gastrointestinal endoscopy on the basis of evidence‐based medicine in collaboration with the Japanese Society for Anesthesiologists. The present guidelines comprise 14 statements, five of which were judged to be valid on the highest evidence level and three on the second highest level. The guidelines are not intended to strongly recommend the use of sedation for gastrointestinal endoscopy, but rather to indicate the policy as to the choice of appropriate procedures when such sedation is deemed necessary. In clinical practice, the final decision as to the use of sedation should be made by physicians considering patient willingness and physical condition.

Basic technique of FNA

EUS-guided FNA (EUS-FNA) has emerged as an effective technique for tissue diagnosis in patients with abnormalities of various organs. For this reason, EUS-FNA is now frequently incorporated into the management algorithms of patients with suspected mediastinal or abdominal neoplasms. Moreover, interventional EUS has recently spread worldwide, not only for diagnostic intervention but also for therapeutic intervention. The use of EUS-FNA is fundamental in various interventional EUS, and learning the basic techniques of EUS-FNA is important to perform EUS-FNA with high efficacy. In this article, the basic EUSFNA technique is interpreted by referring to the medical literature.

Two Cases of Retroperitoneal Liposarcoma Diagnosed Using Endoscopic Ultrasound-Guided Fine-Needle Aspiration (EUS-FNA)

This report describes our experience with two cases that were ultimately diagnosed as retroperitoneal liposarcoma using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Case 1 is that of a 54-year-old woman with chief complaints of nausea and abdominal distention. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large (15 cm diameter) tumor, which was significantly compressing the stomach and apparently occupied the entire left abdominal cavity. Although advanced primary gastrointestinal stromal tumor (GIST) or retroperitoneal tumor was inferred as the differential diagnosis, a definitive diagnosis was difficult using imaging alone. After EUS-FNA was done, the tumor was diagnosed histopathologically as high-grade liposarcoma. Case 2 is that of a 73-year-old man. Abdominal ultrasonography and CT showed a 6 cm diameter tumor within the pelvic cavity. The tumor had high MRI signal-intensity on both T1 and T2 images. Endorectal EUS showed a hyperechoic mass. The images suggested lipoma or liposarcoma containing lipoma-like components. Myxoid liposarcoma was revealed by subsequent EUS-FNA. Performing EUS-FNA was clinically useful for determining the subsequent therapeutic strategy in these cases where a tumor of unknown origin existed in the retroperitoneum.

Usefulness of endoscopic ultrasound-guided fine-needle aspiration with a forward-viewing and curved linear-array echoendoscope for small gastrointestinal subepithelial lesions

Background and study aims: It is difficult to perform endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of small gastrointestinal (GI) subepithelial lesions (SELs) approximately 10 mm in diameter. This study was undertaken to evaluate the feasibility, safety, and diagnostic ability of EUS-FNA with a forward-viewing and curved linear-array echoendoscope (FVCLA-ES) that has a cap for small SELs. Patients and methods: The study enrolled 8 patients who had small upper GI SELs approximately 10 mm in diameter. To fix the SELs during FNA, a cap device was attached to the scope tip. Results: The mean (standard deviation [SD]) diameter of the SELs was 10.6 mm (2.94). Even small lesions were well targeted for FNA when the FVCLA-ES with a cap device was used. The mean (SD) number of passes was 4.6 (1.59). Adequate samples were obtained from 7 patients (87.5 %) – in 6 (75 %) for cytology and in 4 (50 %) for histologic examination with immunohistochemical (IHC) staining. No complication occurred. Gastrointestinal stromal tumor (GIST) in 2 patients and leiomyoma in 2 patients were definitively diagnosed with IHC staining. Conclusions: EUS-FNA with an FVCLA-ES that has a cap device is feasible and safe. This technique is expected to contribute to histologic diagnosis, even in small SELs.

Intraductal ultrasonographic anatomy of biliary varices in patients with portal hypertension.

Background and Objectives: The term, portal biliopathy, denotes various biliary abnormalities, such as stenosis and/or dilatation of the bile duct, in patients with portal hypertension. These vascular abnormalities sometimes bring on an obstructive jaundice, but they are not clear which vessels participated in obstructive jaundice. The aim of present study was clear the bile ductal changes in patients with portal hypertension in hopes of establishing a therapeutic strategy for obstructive jaundice caused by biliary varices. Materials and Methods: Three hundred and thirty-seven patients who underwent intraductal ultrasound (IDUS) during endoscopic retrograde cholangiography for biliary abnormalities were enrolled. Portal biliopathy was analyzed using IDUS. Results: Biliary varices were identified in 11 (2.7%) patients. IDUS revealed biliary varices as multiple, hypoechoic features surrounding the bile duct wall. These varices could be categorized into one of two groups according to their location in the sectional image of bile duct: epicholedochal and paracholedochal. Epicholedochal varices were identified in all patients, but paracholedochal varices were observed only in patients with extrahepatic portal obstruction. Conclusion: IDUS was useful to characterize the anatomy of portal biliopathy in detail.

Japanese Clinical Guidelines for Endoscopic Treatment of Pancreatolithiasis.

Objectives In addition to surgery, procedures for patients with pancreatolithiasis are developing; therefore, establishing practical guidelines for the management of pancreatolithiasis is required. Methods Three committees (the professional committee for asking clinical questions (CQs) and statements by Japanese endoscopists, the expert panel committee for rating statements by the modified Delphi method, and the evaluating committee by moderators) were organized. Eight endoscopists and a surgeon for pancreatolithiasis made the CQs and statements from a total of 694 reports of published literature by PubMed search (from 1983 to 2012). The expert panelists individually rated these clinical statements using a modified Delphi approach, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. Results The professional committee made 3, 7, and 10 CQs and statements for the concept and pathogenesis, diagnosis, and treatment, respectively. The expert panelists regarded them as valid after a 2-round modified Delphi approach. Conclusions After evaluation by the moderators, the Japanese clinical guidelines for pancreatolithiasis were established. Further discussions and studies for international guidelines are needed.

INTERVENTIONAL ENDOSCOPIC ULTRASONOGRAPHY: APPLICATIONS FOR CANCER RELATED TREATMENT

For tissue diagnosis in patients with abnormalities of various organs, endoscopic ultrasonography (EUS)‐guided fine needle aspiration (EUS‐FNA) has emerged as an effective technique. Subsequently, EUS‐guided fine needle injection (EUS‐FNI) has expanded the clinical utility of EUS. Several applications of EUS‐FNI for anti‐cancer efforts have included celiac nerve blocking and drug delivery into tumors, such as ablation, chemotherapy, gene therapy, and cytoimplantation. Furthermore, chemosensitivity tests with materials obtained using EUS‐FNA are available to produce tailor‐made medicines. Demonstrably, EUS‐guided intervention has opened new and exciting clinical applications for the management of malignancies.