Sonazoid is a new second-generation microbubble contrast for ultrasonography. In this pilot study, the diagnostic role of contrast-enhanced harmonic imaging endoscopic ultrasonography (CH-EUS) with Sonazoid was prospectively evaluated in preoperative T-staging of pancreaticobiliary malignancies. Patients with suspected pancreaticobiliary malignancies underwent CH-EUS by a single examiner. After the lesions were observed carefully with conventional harmonic imaging EUS (H-EUS), CH-EUS was performed with intravenous injection of Sonazoid. A reviewer who was blinded reviewed the recordings of H-EUS and CH-EUS and assessed the T-staging. The accuracy of H-EUS and CH-EUS for T-staging was compared to the results of surgical histopathology in patients who underwent surgery. Twenty-six patients underwent surgical resection and could be included in the study. The final diagnosis were pancreatic cancer in 11, bile duct cancer in 7, gallbladder cancer in 4 and ampullary cancer in 4. The overall accuracy of H-EUS and CH-EUS for T-staging were 69.2 (18/26) and 92.4% (24/26), respectively (p < 0.05). There were disagreement in six cases between H-EUS and CH-EUS. CH-EUS staged correctly in all of these six cases, whereas H-EUS misdiagnosed the depth of invasion in one case of gallbladder cancer and one case of ampullary cancer, and invasion of portal vein in two cases of pancreatic cancer and two cases of bile duct cancer. The depth of invasion of biliary cancer and vascular invasion of pancreatic and biliary cancer could be demonstrated more clearly with CH-EUS compared to H-EUS. CH-EUS has the potential to improve the diagnostic accuracy of preoperative T-staging of pancreaticobiliary malignancies.

Objective. Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic carcinoma (PC) despite recent advances in imaging tests. The aim of the study was to evaluate whether the quantitative perfusion analysis using software “Time intensity curve” with contrast-enhanced harmonic EUS (CH-EUS) facilitate the differentiation of AIP from PC. Methods. Consecutive patients with focal AIP and pancreatic carcinoma who underwent CH-EUS from January 2009 to September 2010 were analyzed. CH-EUS was performed with intravenous administration of an ultrasonographic contrast (Sonazoid) and electronic radial echoendoscope. The graph of time intensity curve (TIC) for pancreatic mass was generated to depict the changes in signal intensity over time within the region of interest (ROI). ROI was placed to cover an area with a pancreatic mass lesion. Based on the analysis of TIC, base intensity before injection (BI), peak intensity (PI), time to peak, and maximum intensity gain (MIG: PI-BI) were calculated. Results. Eight patients with focal AIP and twenty-two patients with PC were evaluated by TIC. PI and MIG of mass lesion of AIP were significantly higher than that of PC (21.4 dB vs. 9.6 dB, 17.5 vs. 6.6). Receiver operating characteristics analysis yielded an optimal MIG cutoff value of 12.5 with high sensitivity and specificity. Conclusion. Pancreatic mass lesions of AIP and PC exhibited markedly different patterns with the TIC. This novel diagnostic modality using TIC generated by CH-EUS might offer an opportunity to improve accuracy in the differential diagnosis between pancreatic mass lesion of AIP and PC.

Background and Aims. There are limited data on the differences in diagnostic yield between 25-gauge and 22-gauge EUS-FNA needles. This prospective study compared the difference in diagnostic yield between a 22-gauge and a 25-gauge needle when performing EUS-FNA. Methods. Forty-three patients with intraluminal or extraluminal mass lesions and/or lymphadenopathy were enrolled prospectively. EUS-FNA was performed for each mass lesion using both 25- and 22-gauge needles. The differences in accuracy rate, scoring of needle visibility, ease of puncture and quantity of obtained specimen were evaluated. Results. The overall accuracy of 22- and 25-gauge needle was similar at 81% and 76% respectively (N.S). Likewise the visibility scores of both needles were also similar. Overall the quantity of specimen obtained higher with the 22-gauge needle (score: 1.64 vs. 𝑃<.001). However the 25-gauge needle was significantly superior to the 22-gauge needle in terms of ease of puncture (score: 1.9 vs. 1.29, 𝑃<.001) and in the quantity of specimen in the context of pancreatic mass EUS-FNA (score: 1.8 vs. 1.58, 𝑃<.05). Conclusion. The 22-gauge and 25-gauge needles have similar overall diagnostic yield. The 25-gauge needle appeared superior in the subset of patients with hard lesions and pancreatic masses.

Background and study aims: A randomized in vivo animal study previously demonstrated that topical injection of mesna solution (sodium-2-mercaptoethanesulfonate) chemically softened submucosal connective tissues and facilitated mechanical dissection of the submucosal tissue plane. The present study evaluated the technical feasibility and safety of chemically assisted endoscopic submucosal dissection (CA-ESD) using mesna in 20 consecutive patients who underwent endoscopic excision of gastric neoplasm. Materials and methods: Following the margination of the lesion with a mucosal circumcision, 4 – 12 mL of 10 % mesna solution was injected into the submucosal layer. Mechanical submucosal dissection was then performed by bluntly cleaving the chemically treated submucosal layer with the tip of a cap-fitted gastroscope. The use of cautery was restricted to prophylactic hemostasis, dissection of the coagulated vessels and persistent submucosal tissues, and the final snare resection. Post-therapeutic ulceration repair and adverse events were followed up during a 1-week hospitalization and by repeat endoscopies at 1 day, 1 week, and 1 month after the procedure. Results: Sixteen gastric cancers and four adenomas were treated in this study. The sampled tissue measured 38.25 ± 14.53 mm, with an en bloc resection rate of 100 %. Mean operation time was 21.17 ± 11.6 minutes. The time spent using cautery was limited to 26.1 % of the total submucosal dissection time. Ulcerations healed normally without complications. Conclusions: This preliminary study demonstrates that submucosal injection of mesna facilitates and expedites mechanical submucosal dissection. The major limitations in this study include the single-arm study design and a small patient population.

To assess the feasibility and usefulness of endoscopic ultrasound-guided transgastric drainage (EUS-GD) in patients who required early postoperative drainage of peripancreatic fluid collection or postoperative pancreatic fistulas after pancreatic surgery. Between May 2012 and January 2016, 33 patients who developed peripancreatic fluid collection or postoperative pancreatic fistulas after pancreatic resection underwent EUS-GD or percutaneous drainage (PTD). Outcomes were compared retrospectively. The drainage procedures were performed on postoperative day 4 to 71 (median, 12) in the EUS-GD group, and 7 to 35 (median, 14) in the PTD group. Technical and clinical success rates reached 92% (11/12) in the EUS-GD group, and 100% (21/21) in the PTD group with no complications or mortality. The duration of hospital stay after drainage was 10 to 44 (median, 15) days for EUS-GD, compared with 10 to 39 (median, 21) days for PTD. EUS-GD is a safe and useful method for early drainage, which could be a good alternative to PTD.