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1034
P12
Ultrasound in Medicine and Biology
indexing portal and splenic vein, aorta, inferior vena cava (IVC) and SMA. In the use of convex model, it is recommended to demonstrate bilio-pancreatic tract though the stomach and duodenum. Premedication and patient’s position are same with those of radial model. Through the gastric wall, aorta, SMA and splenic artery and vein are indices to observe the pancreas body and tail. EUS images of portal vein IVC are indices for demonstrating the biliary tract and head of the pancreas trough the duodenal wall. Manipulation of EUS scope is different in radial and convex models. Standardization of EUS scan is important both in the radial and convex models of ultrasound endoscope to achieve the aim of EUS procedures. 1034 Role of intraductal ultrasound (IDUS) for bilio-pancreatic lesion Shim CS, Soonchunhyang University Hospital, Korea Introduction: Endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging. Usefulness and effectiveness of EUS have been established during the past few years. Recently, developed ultrasonic miniprobes can be passed through the working channel of endoscopes to provide high-frequency ultrasound images. Catheterprobes with diameters of 3 mm or less provide a means for endoluminal US imaging in conjunction with diagnostic endoscopy. The ultrasonic miniprobe is an ideal instrument for insertion into fluid-filled tubular structures such as the bile duct system, which are only slightly larger in diameter than the miniprobe itself. In some cases, however, it is very difficult to insert the miniature ultrasonic probe into the bile duct. Recently, wire-guided IDUS was developed to overcome this problem of conventional ultrasonic probe. Materials and Procedures: To date, two principal miniprobe systems exist: electronic phased array and mechanical radial sector scan system. However, at present mechanical probes are commonly used as they outperform electronic probes in terms of image quality, depth of penetration, and durability. Because their diameter is only about 2 mm, these ultrasonic probes may be passed through the biopsy channel of routinely used duodenoscopes. The small diameter enables IDUS of the biliopancreatic duct after transpapillary or transhepatic insertion. The probe tip can be localized fluoroscopically. Images are continuously recorded on videotape upon retraction of the probe. Clinical Applications: These probes have been adapted for imaging of the biliopancreatic ductal system. During ERCP ultrasonic miniprobe insertion into the bile duct or pancreatic duct system is easier, quicker and safer to perform and thus IDUS might add valuable information regarding the periductular tissue to diagnostic and therapeutic ERCP. IDUS offers high-quality cross-sectional images of the bile duct, pancreatic duct and nearby regions. Possible clinical indications for IDUS of the biliopancreatic ductal systems are choledocholithasis, characterization of biliopancreatic strictures, locoregional tumor staging and localization of islet cell tumors negative on endoscopic ultrasonography. One of the most promising applications of IDUS imaging is the staging of biliary cancers. The bile duct and adjacent vessels are visualized in transverse section. Hepatic artery invasions and portal vein invasions can thus be demonstrated. IDUS has also been shown to be clinically useful in evaluating the extent of cancers of the major duodenal papilla. In fact, recent study found IDUS to be superior to EUS in staging polypoid tumors of the major papilla. Complications and Safety: In transpapillary bile duct scanning, mild acute pancreatitis occurs rarely, and resolves with conservative management with fasting and the administration of protease inhibitor. No other complications have been observed so far. In transhepatic bile duct scanning, no complication due to insertion of the ultrasonic probe has been reported. Conclusion: IDUS is very useful diagnostic tool for evaluating and assessing various biliopancreatic diseases.
Volume 32, Number 5S, 2006 1035 Role of diagnostic EUS-guided FNA Kim J-O, Cho YD, Soonchunhyang University Hospital, Korea EUS were initially developed to improve better ultrasound imaging of the pancreas; it was widely used for the differential diagnosis of the gastrointestinal and biliopancreatic lesions, such as to stage gastrointestinal/biliopancreatic cancers and to evaluate tumors arising from the gut wall. But EUS as an imaging modality has limited specificity, when attempting to distinguish benign from malignant lymph nodes, pancreatic masses, giant gastric folds and malignant gastrointestinal tumors. Although certain features may suggest malignancy, tissue sampling is still required to confirm the diagnosis. EUS-guided FNA is limited to areas in which the EUS can visualize the target lesion and where the needle has a clear pathway without intervening vessels or cancer. The clinical utility of EUS-guided FNA appears to be greatest in the diagnosis and staging of pancreatic cancer and in the nodal staging of gastrointestinal, pancreatic and pulmonary malignancies. Every lesion imaged by EUS does not need to be sampled by FNA. The additional clinical impact of EUS guided puncture should be considered prior to every FNA. A fundamental principle in establishing indications for EUS-guided FNA is a determination as to whether or not the information obtained has the potential to affect patient management. If the result of the FNA cannot affect patient management the procedure should not be performed. The current common and possible indication where EUS guide FNA is important to adjunct EUS are; unresectable pancreatic mass; undiagnosed pancreatic mass in which FNA may be performed to try to differentiate chronic pancreatitis from pancreatic cancer; suspicious lymph nodes associated with esophageal cancer; posterior mediastinal LN associated with nonsmall cell lung cancer; undiagnosed posterior mediastinal mass in which the differential could include lymphoma, small cell lung cancer and enlarged lymph nodes from mediastinal infections, and others; in a patient with known or suspected cancer, EUS detects celiac LN, liver mass and ascites. EUS FNA may be useful for the early diagnosis of malignant ascites; pelvic mass adjacent to rectum/distal sigmoid; submucosal tumors if FNA may change patient management; recurrent cancer in or adjacent to an anastomosis not diagnosed by conventional endoscopic biopsy (rectal, esophageal and gastric cancer); lesions suspected of malignancy outlined by EUS and not finally diagnosed by other modalities (liver, spleen, left adrenal). However there are some problems remaining about the false negative cases, histological diagnosis from the very tiny materials and the risk of disseminating the malignant cells by the procedure. For the better result of EUS-guide FNA, multidisciplinary team approach, to provide detailed clinical information to the cytopathologist, extra passes for special studies are needed. Prior to perform the EUS-guided FNA endosonographer have to think of the clinical impact and then push that needle. 1036 Role of therapeutic EUS-guided FNA Irisawa A, Takagi T, Hikichi T, Fukushima Medical University School of Medicine, Japan The development of curved linear-array endoscopic ultrasound (EUS), which allow real-time visualization of a needle axis has overcome the inability of radial EUS concerning with tissue sampling, and moreover has permitted various EUS-guided interventions. Therefore, interventional EUS is applied not only for definite diagnosis but also EUSguided therapy. To date, there are many reports of therapeutic interventional EUS including experimental model, such as EUS-guided fine needle injection (FNI) (e.g., celiac plexus neurolysis, anti-cancer therapy), ablation (e.g., using radiofrequency), stent-indwelling (e.g., pancreatic pseudocysts drainage via gastrointestinal wall) and suturing.
Ultrasound in Medicine and Biology
indexing portal and splenic vein, aorta, inferior vena cava (IVC) and SMA. In the use of convex model, it is recommended to demonstrate bilio-pancreatic tract though the stomach and duodenum. Premedication and patient’s position are same with those of radial model. Through the gastric wall, aorta, SMA and splenic artery and vein are indices to observe the pancreas body and tail. EUS images of portal vein IVC are indices for demonstrating the biliary tract and head of the pancreas trough the duodenal wall. Manipulation of EUS scope is different in radial and convex models. Standardization of EUS scan is important both in the radial and convex models of ultrasound endoscope to achieve the aim of EUS procedures. 1034 Role of intraductal ultrasound (IDUS) for bilio-pancreatic lesion Shim CS, Soonchunhyang University Hospital, Korea Introduction: Endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging. Usefulness and effectiveness of EUS have been established during the past few years. Recently, developed ultrasonic miniprobes can be passed through the working channel of endoscopes to provide high-frequency ultrasound images. Catheterprobes with diameters of 3 mm or less provide a means for endoluminal US imaging in conjunction with diagnostic endoscopy. The ultrasonic miniprobe is an ideal instrument for insertion into fluid-filled tubular structures such as the bile duct system, which are only slightly larger in diameter than the miniprobe itself. In some cases, however, it is very difficult to insert the miniature ultrasonic probe into the bile duct. Recently, wire-guided IDUS was developed to overcome this problem of conventional ultrasonic probe. Materials and Procedures: To date, two principal miniprobe systems exist: electronic phased array and mechanical radial sector scan system. However, at present mechanical probes are commonly used as they outperform electronic probes in terms of image quality, depth of penetration, and durability. Because their diameter is only about 2 mm, these ultrasonic probes may be passed through the biopsy channel of routinely used duodenoscopes. The small diameter enables IDUS of the biliopancreatic duct after transpapillary or transhepatic insertion. The probe tip can be localized fluoroscopically. Images are continuously recorded on videotape upon retraction of the probe. Clinical Applications: These probes have been adapted for imaging of the biliopancreatic ductal system. During ERCP ultrasonic miniprobe insertion into the bile duct or pancreatic duct system is easier, quicker and safer to perform and thus IDUS might add valuable information regarding the periductular tissue to diagnostic and therapeutic ERCP. IDUS offers high-quality cross-sectional images of the bile duct, pancreatic duct and nearby regions. Possible clinical indications for IDUS of the biliopancreatic ductal systems are choledocholithasis, characterization of biliopancreatic strictures, locoregional tumor staging and localization of islet cell tumors negative on endoscopic ultrasonography. One of the most promising applications of IDUS imaging is the staging of biliary cancers. The bile duct and adjacent vessels are visualized in transverse section. Hepatic artery invasions and portal vein invasions can thus be demonstrated. IDUS has also been shown to be clinically useful in evaluating the extent of cancers of the major duodenal papilla. In fact, recent study found IDUS to be superior to EUS in staging polypoid tumors of the major papilla. Complications and Safety: In transpapillary bile duct scanning, mild acute pancreatitis occurs rarely, and resolves with conservative management with fasting and the administration of protease inhibitor. No other complications have been observed so far. In transhepatic bile duct scanning, no complication due to insertion of the ultrasonic probe has been reported. Conclusion: IDUS is very useful diagnostic tool for evaluating and assessing various biliopancreatic diseases.
Volume 32, Number 5S, 2006 1035 Role of diagnostic EUS-guided FNA Kim J-O, Cho YD, Soonchunhyang University Hospital, Korea EUS were initially developed to improve better ultrasound imaging of the pancreas; it was widely used for the differential diagnosis of the gastrointestinal and biliopancreatic lesions, such as to stage gastrointestinal/biliopancreatic cancers and to evaluate tumors arising from the gut wall. But EUS as an imaging modality has limited specificity, when attempting to distinguish benign from malignant lymph nodes, pancreatic masses, giant gastric folds and malignant gastrointestinal tumors. Although certain features may suggest malignancy, tissue sampling is still required to confirm the diagnosis. EUS-guided FNA is limited to areas in which the EUS can visualize the target lesion and where the needle has a clear pathway without intervening vessels or cancer. The clinical utility of EUS-guided FNA appears to be greatest in the diagnosis and staging of pancreatic cancer and in the nodal staging of gastrointestinal, pancreatic and pulmonary malignancies. Every lesion imaged by EUS does not need to be sampled by FNA. The additional clinical impact of EUS guided puncture should be considered prior to every FNA. A fundamental principle in establishing indications for EUS-guided FNA is a determination as to whether or not the information obtained has the potential to affect patient management. If the result of the FNA cannot affect patient management the procedure should not be performed. The current common and possible indication where EUS guide FNA is important to adjunct EUS are; unresectable pancreatic mass; undiagnosed pancreatic mass in which FNA may be performed to try to differentiate chronic pancreatitis from pancreatic cancer; suspicious lymph nodes associated with esophageal cancer; posterior mediastinal LN associated with nonsmall cell lung cancer; undiagnosed posterior mediastinal mass in which the differential could include lymphoma, small cell lung cancer and enlarged lymph nodes from mediastinal infections, and others; in a patient with known or suspected cancer, EUS detects celiac LN, liver mass and ascites. EUS FNA may be useful for the early diagnosis of malignant ascites; pelvic mass adjacent to rectum/distal sigmoid; submucosal tumors if FNA may change patient management; recurrent cancer in or adjacent to an anastomosis not diagnosed by conventional endoscopic biopsy (rectal, esophageal and gastric cancer); lesions suspected of malignancy outlined by EUS and not finally diagnosed by other modalities (liver, spleen, left adrenal). However there are some problems remaining about the false negative cases, histological diagnosis from the very tiny materials and the risk of disseminating the malignant cells by the procedure. For the better result of EUS-guide FNA, multidisciplinary team approach, to provide detailed clinical information to the cytopathologist, extra passes for special studies are needed. Prior to perform the EUS-guided FNA endosonographer have to think of the clinical impact and then push that needle. 1036 Role of therapeutic EUS-guided FNA Irisawa A, Takagi T, Hikichi T, Fukushima Medical University School of Medicine, Japan The development of curved linear-array endoscopic ultrasound (EUS), which allow real-time visualization of a needle axis has overcome the inability of radial EUS concerning with tissue sampling, and moreover has permitted various EUS-guided interventions. Therefore, interventional EUS is applied not only for definite diagnosis but also EUSguided therapy. To date, there are many reports of therapeutic interventional EUS including experimental model, such as EUS-guided fine needle injection (FNI) (e.g., celiac plexus neurolysis, anti-cancer therapy), ablation (e.g., using radiofrequency), stent-indwelling (e.g., pancreatic pseudocysts drainage via gastrointestinal wall) and suturing.