Takamitsu Komaki

Prospective comparative study of the EUS guided 25-gauge FNA needle with the 19-gauge Trucut needle and 22-gauge FNA needle in patients with solid pancreatic masses.

Background and Study Aims:  The aim of this prospective study was to compare fine‐needle aspiration guided by endoscopic ultrasonography (EUS‐FNA) using 25‐gauge and 22‐gauge needles with the EUS‐guided 19‐gauge Trucut needle biopsy (EUS‐TNB) in patients with solid pancreatic mass.

Characterization of Small Solid Tumors in the Pancreas: The Value of Contrast-Enhanced Harmonic Endoscopic Ultrasonography

OBJECTIVES:Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS), a novel technology, visualizes parenchymal perfusion in the pancreas. This study prospectively evaluated how accurately CH-EUS characterizes pancreatic lesions and compared its diagnostic ability with that of contrast-enhanced multidetector-row computed tomography (MDCT) and endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA).METHODS:A total of 277 consecutive patients with pancreatic solid lesions that were detected by conventional EUS underwent CH-EUS for evaluation of vascularity. After infusing an ultrasound contrast, CH-EUS was performed by using an echoendoscope and a specific mode for contrast harmonic imaging. On the basis of the intensity of enhancement, the lesions were categorized into four patterns: nonenhancement, hypoenhancement, isoenhancement, and hyperenhancement. For comparison, all patients underwent MDCT. The ability of CH-EUS to differentiate ductal carcinomas from the other solid tumors, particularly small lesions (≤2 cm in diameter) was assessed, and compared with the differentiating abilities of MDCT and EUS-FNA.RESULTS:In terms of reading the CH-EUS images, the κ-coefficient of the interobserver agreement test was 0.94 (P<0.001). CH-EUS-depicted hypoenhancement diagnosed ductal carcinomas with a sensitivity and specificity of 95.1% (95% confidence interval (CI) 92.7–96.7%) and 89.0% (95% CI 83.0–93.1%), respectively. For diagnosing small carcinomas by CH-EUS, the sensitivity and specificity were 91.2 % (95% CI 82.5–95.1%) and 94.4% (95% CI 86.2–98.1%), respectively. CH-EUS-depicted hypervascular enhancement diagnosed neuroendocrine tumors with a sensitivity and specificity of 78.9% (95% CI 61.4–89.7%) and 98.7% (95% CI 96.7–98.8%), respectively. Although CH-EUS and MDCT did not differ significantly in diagnostic ability with regard to all lesions, CH-EUS was superior to MDCT in diagnosing small (≤2 cm) carcinomas (P<0.05). In 12 neoplasms that MDCT failed to detect, 7 ductal carcinomas and 2 neuroendocrine tumors had hypoenhancement and hyperenhancement on CH-EUS, respectively. When CH-EUS was combined with EUS-FNA, the sensitivity of EUS-FNA increased from 92.2 to 100%.CONCLUSIONS:CH-EUS is useful for characterizing conventional EUS-detected solid pancreatic lesions. EUS equipped with contrast harmonic imaging may play an important role in the characterization of small tumors that other imaging methods fail to depict and may improve the diagnostic yield of EUS-FNA.

EUS-Guided Broad Plexus Neurolysis Over the Superior Mesenteric Artery Using a 25-Gauge Needle

OBJECTIVES:Endoscopic ultrasonography (EUS)-guided celiac plexus neurolysis (EUS-CPN) is safe and effective but not beneficial for some patients with extended abdominal cancer. We compared the effectiveness of standard EUS-CPN and EUS-guided broad plexus neurolysis (EUS-BPN) that extends over the superior mesenteric artery (SMA) using a 25-gauge needle.METHODS:Consecutive patients referred to our quaternary EUS centers were eligible for inclusion. To evaluate the neurolytic spread, contrast was mixed with the neurolytic agent and post-procedure computed tomography scanning was performed. The regions containing the celiac, superior, and inferior mesenteric arteries were divided on the frontal plane into six areas: upper right and left, middle right and left, and lower right and left. The number of contrast-bearing areas after EUS-CPN and EUS-BPN were related to the degree of pain relief achieved.RESULTS:A total of 67 patients with advanced abdominal cancer were included (34 EUS-CPN and 33 EUS-BPN). The qualitative variables of the two groups did not differ significantly. The EUS-BPN group had more patients with six contrast-bearing areas (42%) than the EUS-CPN group (0%). These patients had significantly better short-term and long-lasting pain relief than patients with less than five contrast-bearing areas. EUS-BPN patients exhibited significantly greater reductions in days 7 and 30 visual analog pain scale scores than EUS-CPN patients.CONCLUSIONS:Our preliminary data suggested that EUS-BPN using a 25-gauge needle provides patients with advanced abdominal cancer with better pain relief than standard EUS-CPN, and without incurring serious complications. Moreover, it seems that broad neurolysis over the SMA may provide superior analgesia.

Estimation of malignant potential of GI stromal tumors by contrast-enhanced harmonic EUS (with videos)

BACKGROUND Contrast-enhanced harmonic EUS (CEH-EUS) is a new sonographic technique that uses US contrast agents and depicts intratumoral vessels in real time. OBJECTIVE To evaluate whether assessment of tumor vascularity by CEH-EUS can predict the preoperative malignancy risk of GI stromal tumors (GISTs). DESIGN Prospective study to observe GIST vascularity. SETTING Kinki University School of Medicine. PATIENTS Between June 2007 and September 2009, 76 consecutive patients suspected of having subepithelial lesions underwent CEH-EUS. INTERVENTION CEH-EUS was performed by using a prototype echoendoscope in an extended pure harmonic detection mode. MAIN OUTCOME MEASUREMENTS Resected GIST specimens in 29 patients who underwent surgical resection were divided into high-grade (n=16) and low-grade (n=13) malignancy groups based on mitotic activity. The abilities of EUS-guided FNA and CEH-EUS to diagnose the malignant potential were compared. The sensitivities with which contrast-enhanced multidetector CT, power-Doppler EUS, and CEH-EUS detected intratumoral vessels in high-grade malignancy GISTs also were compared. RESULTS CEH-EUS identified irregular vessels and thereby predicted GIST malignancies with a sensitivity, specificity, and accuracy of 100%, 63%, and 83%, respectively. Diagnosis of high-grade malignancy GISTs by EUS-guided FNA had a sensitivity, specificity, and accuracy of 63%, 92%, and 81%, respectively. Contrast-enhanced multidetector CT, power-Doppler EUS, and CEH-EUS detected intratumoral vessels in high-grade malignancy GISTs with sensitivities of 31%, 63%, and 100%, respectively (P<.05). LIMITATIONS A single center was involved in this study. CONCLUSIONS CEH-EUS successfully visualized intratumoral vessels and may play an important role in predicting the malignancy risk of GISTs.

Endoscopic Ultrasonography-Guided Biliary Drainage: Evaluation of a Choledochoduodenostomy Technique

Background: Endoscopic ultrasonography (EUS)-guided choledochoduodenostomy (CDS) is as an alternative to percutaneous transhepatic biliary drainage (PTBD) in patients with biliary obstruction when endoscopic retrograde biliary drainage (ERBD) is unsuccessful. Purpose: We reviewed our experience and technique in patients undergoing EUS-CDS. Patients: Over a 2-year period to December 2008, 15 patients with unsuccessful ERBD underwent EUS-CDS. Methods: EUS-guided needle puncture was performed to access the bile duct from the duodenal bulb. After cholangiography, a guidewire was inserted through the needle and directed to the hepatic hilum. The punctured fistula was then dilated with a biliary dilator and a plastic stent was inserted. Results: The technical success rate of EUS-CDS was 93% (14/15 patients); 1 patient underwent an EUS-guided rendezvous approach because the choledochoduodenal fistula could not be dilated. Decompression of the bile duct was achieved in all patients. Complications included cholangitis in 4 patients, self-limiting local peritonitis in 2 and distal stent migration in 1 patient. The median follow-up time was 125 days and the median duration of stent patency was 99 days. Conclusion: EUS-CDS may be effective for patients following unsuccessful ERBD and offers an attractive alternative to PTBD.

Characterization of intra-abdominal lesions of undetermined origin by contrast-enhanced harmonic EUS (with videos).

BACKGROUND The diagnosis of intra-abdominal lesions of undetermined origin is often a challenge for endoscopists and radiologists. OBJECTIVE To evaluate the microvasculature of benign and malignant intra-abdominal lesions by contrast-enhanced harmonic EUS (CEH-EUS) and to investigate its usefulness for discriminating between malignant and benign lesions. DESIGN The vascularity of intra-abdominal lesions of undetermined origin was observed by using CEH-EUS. The lesions were classified according to their vascular patterns. The effectiveness of CEH-EUS in differentiating malignant from benign lesions was evaluated. SETTING Kinki University School of Medicine, Osaka, Japan. PATIENTS Forty-three patients, each with a lesion of undetermined origin, were evaluated prospectively by CEH-EUS between March 2007 and March 2009. INTERVENTIONS CEH-EUS was performed by using a prototype echoendoscope and the extended pure harmonic detection mode (a specific mode for contrast harmonic imaging). MAIN OUTCOME MEASUREMENTS The lesions were categorized by 2 physicians as having no, homogeneous, or heterogeneous enhancement. A consensus was reached for each case offline. How the benign and malignant groups differed in terms of their enhancement patterns was examined. RESULTS The kappa coefficient of the interobserver agreement test was 0.953 (P < .001). Of the 27 malignant lesions, 26 (96.3%) exhibited heterogeneous enhancement. The 1 remaining malignant lesion (3.7%) showed homogeneous enhancement. Of the 16 benign lesions, none displayed heterogeneous enhancement, and 12 (75%) and 4 (25%) exhibited homogeneous and no enhancement, respectively. The malignant and benign lesion groups differed significantly in terms of homogeneous and heterogeneous enhancement (P < .001). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy with which CEH-EUS differentiated malignant from benign lesions were 96.3%, 100%, 100%, 94.1%, and 97.6%, respectively. LIMITATIONS A single medical unit with a limited number of patients. CONCLUSIONS CEH-EUS depicted the microvasculature of intra-abdominal lesions of undetermined origin very clearly and may be useful for characterizing such lesions.

New techniques and future perspective of EUS for the differential diagnosis of pancreatic malignancies: contrast harmonic imaging.

Although endoscopic ultrasonography (EUS) has the advantage over other imaging methods in that it is possible to obtain high resolution images of the pancreas, it is limited in its ability to characterize pancreatic masses. Contrast‐enhanced power Doppler ultrasonography suffers from several limitations such as blooming artifacts, poor spatial resolution, low sensitivity to slow flow and high sensitivity to motion artifacts. Recently, EUS system specific for contrast harmonic imaging has been developed. The use of this EUS system enabled us to observe images of microcirculation and parenchymal perfusion without Doppler‐related artifacts in the pancreas. Contrast‐enhanced harmonic EUS could diagnose pancreatic carcinomas as hypovascular masses with a high sensitivity (89–96%) and specificity (64–88%). Contrast‐enhanced harmonic EUS also discriminates mural nodules from mucous clots in the intraductal papillary mucinous neoplasms.

Endoscopic Ultrasonography and Contrast-Enhanced Endoscopic Ultrasonography

Endoscopic ultrasonography (EUS) is superior to all other imaging modalities in detecting small pancreatic cancers. However, its ability to characterize hypoechoic pancreatic masses is limited: most carcinomas, neuroendocrine tumors, and inflammatory pseudotumors are simply depicted as hypoechoic masses. Contrast enhancement helps EUS to characterize such hypoechoic masses. Intravenous ultrasound (US) agents increase the signal from the blood and, thus, act as amplifiers and improve visualization of blood flow in small vessels using Doppler US. Contrast-enhanced Doppler EUS can differentiate small pancreatic carcinomas that cannot be detected by other imaging modalities. The development of second-generation US contrast agents and an EUS system with a broad-band transducer enabled the visualization of microvessels and the parenchymal perfusion in the pancreas. This contrast-enhanced harmonic EUS has shown that most pancreatic cancers exhibit hypovascular heterogeneous enhancement with irregular network-like microvessels. Moreover, it can diagnose pancreatic cancers with a high sensitivity (89–92%).

Endoscopic Ultrasound-Guided Neurolysis in Pancreatic Cancer

Abdominal pain in patients with pancreatic cancer is a common symptom that is often difficult to manage. Opioids are frequently used in an attempt to mitigate pain; however, side effects may develop. Celiac plexus neurolysis (CPN) affords effective pain control in patients with pancreatic cancer and is not associated with opioid side effects. Endoscopic ultrasound (EUS)-guided CPN has demonstrated safety and efficacy due to real-time imaging and anterior access to the celiac plexus from the posterior gastric wall, thereby avoiding complications related to the puncture of spinal nerves, arteries and the diaphragm, and is now practiced widely. Furthermore, two new techniques of EUS-guided neurolysis for abdominal pain management in pancreatic cancer patients have recently been developed. The first technique is EUS-guided celiac ganglia neurolysis (EUS-CGN) in which EUS facilitates CGN by enabling direct injection into the individual celiac ganglion, and the second technique is EUS-guided broad plexus neurolysis (EUS-BPN) which extends over the superior mesenteric artery. This review provides evidence for the efficacy of EUS-CPN. Particular attention is paid to the two new techniques of EUS-guided neurolysis, EUS-CGN and EUS-BPN.

PRESENT STATUS AND FUTURE PERSPECTIVE OF EUS‐GUIDED DRAINAGE

Development of the curved linear (convex) array echoendoscope has enabled procedures that utilize interventional endoscopic ultrasonography (EUS), such as EUS‐guided drainage. EUS‐guided pseudocyst drainage creates a fistula between the pseudocyst and the gastric or duodenal lumen. This treatment is superior to conventional endoscopic transmural drainage with respect to prevention from complications such as bleeding, because ultrasonographic observation permits easy visualization of the interposing vessels and real‐time visualization of needle procedure. Endoscopic ultrasonography‐guided drainage can also be applied to pancreatobiliary drainage. In cases where endoscopic retrograde cholangiopancreatography (ERCP) is unsuccessful in the treatment of obstructive jaundice and chronic obstructive pancreatitis, transmural drainage of bile and pancreatic juice under EUS guidance may supplant the percutaneous transhepatic biliary drainage and the surgical treatment.