Endoscopic submucosal dissection (ESD) is an innovative advance in the treatment of early gastrointestinal (GI) cancer without lymph node metastases and precancerous lesions as it is an effective and safe therapeutic method. ESD has also been a promising therapeutic option for removal of submucosal tumors (SMTs) for improving the completeness of resection of a large lesion. Endoscopic ultrasonography (EUS) can be used to detect the depth of invasion during the preoperative evaluation because of its close proximity to the lesion. EUS-guided fine-needle aspiration can be used to increase the diagnostic accuracy of EUS in determining the malignant lymph node. EUS is considered to be a useful imaging procedure to characterize early GI cancer, which is suspicious for submucosal invasion, and the most accurate procedure for detecting and diagnosing SMTs for further treatment. In the process of ESD, EUS can also be used to detect surrounding blood vessels and the degree of fibrosis; this may be helpful for predicting procedure time and decreasing the risk of bleeding and perforation. EUS-guided injection before ESD renders the endoscopic resection safe and accurate. Therefore, EUS plays an important role in the use of ESD. However, compared to conventional endoscopic staging, EUS sometimes can under or overstage the lesion, and the diagnostic accuracy is controversial. In this review, we summarize the latest research findings regarding the role of EUS in ESD.

Intraductal ultrasonography (IDUS) provides real-time, cross-sectional imaging of pancreatobiliary ducts and surrounding structures during endoscopic retrograde cholangiopancreatography using a high-frequency ultrasound (US) transducer. Hence, IDUS has been considered a sensitive tool in the evaluation of suspicious choledocholithiasis and neoplasms, to help distinguish between benign and malignant bile duct strictures or wall thickness, and to assess tumor extension and invasion depth. With the rapid development and enriched choices of sensitive diagnostic modalities include but are not limited to endoscopic US, peroral cholangioscopy, and confocal laser endomicroscopy, it is needed to systematically assess the role of IDUS in the investigation of pancreatobiliary diseases. Some new developments and innovative use of IDUS techniques will be discussed in this paper with the review of literature.

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure that has become an important tool in diagnosis and staging of mediastinal lymph node (LN) lesions in lung cancer. Adequate sedation is an important part of the procedure since it provides patient's comfort and potentially increases diagnostic yield. We aimed to compare deep sedation (DS) versus moderate sedation (MS) in patients undergoing EBUS-TBNA procedure. Methods: PubMed, EMBASE, MEDLINE, and Cochrane Library were searched for English studies of clinical trials comparing the two different methods of sedations in EBUS-TBNA until December 2015. The overall diagnostic yield, LN size sampling, procedural time, complication, and safety were evaluated. Results: Six studies with 3000 patients which compared two different modalities of sedation in patients performing EBUS-TBNA were included in the study. The overall diagnostic yield of DS method was 52.3%-100% and MS method was 46.1%-85.7%. The overall sensitivity of EBUS-TBNA of DS method was 98.15%-100% as compared with 80%-98.08% in MS method. The overall procedural times were 27.2-50.9 min and 20.6-44.1 min in DS and MS groups, respectively. The numbers of LN sampled were between 1.33-3.20 nodes and 1.36-2.80 nodes in DS and MS groups, respectively. The numbers of passes per LN were 3.21-3.70 passes in DS group as compared to 2.73-3.00 passes in MS group. The mean of LN size was indifferent between two groups. None of the studies included reported serious adverse events. Conclusions: Using MS in EBUS-TBNA has comparable diagnostic yield and safety profile to DS. The decision on the method of sedation for EBUS-TBNA should be individually selected based on operator experience, patient preference, as well as duration of the anticipated procedure.

Background and Objectives: Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum. Patients and Methods: Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE. Results: Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively. Conclusions: EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

Background and Objectives: Percutaneous portal vein (PV) stent placement is used to manage PV occlusion or stenosis caused by malignancy. The use of endoscopic ultrasonography (EUS) has expanded to include vascular interventions. The aim of this study was to examine the technical feasibility and safety of EUS-guided transhepatic PV stent placement in a live porcine model. Materials and Methods: EUS-guided transhepatic PV stent placement was performed in six male miniature pigs under general anesthesia using forward-viewing echoendoscope. Under EUS guidance, the left intrahepatic PV was punctured with a 19-gauge fine-needle aspiration (FNA) needle and a 0.025 inch guidewire inserted through the needle and into the main PV. The FNA needle was then withdrawn and a needle-knife inserted to dilate the tract. Under EUS and fluoroscopic guidance, a noncovered metal stent was inserted over the guidewire and released into the main PV. Results: A PV stent was placed successfully in all six pigs with no technical problems or complications. The patency of the stent in the main PV was confirmed using color Doppler EUS and transhepatic portal venography. Necropsy of the first three animals revealed no evidence of bleeding and damage to intra-abdominal organs or vessels. No complications occurred in the remaining three animals during the 8 weeks observation period. Conclusions: EUS-guided transhepatic PV stent placement can be both technically feasible and safe in a live animal model.

Background and Objectives: Endoscopic ultrasound-guided drainage of walled-off pancreatic fluid collections (PFCs) (pseudocyst [PC]; walled-off necrosis [WON]) utilizes double pigtail plastic stents (PS) and the newer large diameter fully covered self-expandable stents (FCSEMS) customized for PFC drainage. This study examined the impact of type of stent on clinical outcomes and costs. Patients and Methods: Retrospective two-center study. Outcome variables were technical and clinical success, need for repeat procedures, need for direct endoscopic necrosectomy (DEN), and procedure-related costs. Results: A total of 49 (PC: 31, WON: 18) patients were analyzed. Initially, PS was used in 37 and FCSEMS in 12. Repeat transmural drainage was required in 14 (PS: 13 [9 treated with PS, 4 treated with FCSEMS]; FCSEMS: 1 [treated with PS]) due to stent migration (PS: 3; FCSEMS: 1) or inadequate drainage (PS: 10). Technical success was 100%. Initial clinical success was 64.9% (25/38) for PS versus 91.7% (11/12) for FCSEMS (P = 0.074). With repeat transmural stenting, final clinical success was achieved in 94.6% and 100%, respectively (P = 0.411). Compared to FCSEMS, PS was associated with greater need for repeat drainage (34.2% vs. 6.3%, P = 0.032). The need for and frequency of DEN was similar between both groups, but PS required more frequent balloon dilatation. PS was significantly cheaper for noninfected PC. Costs were similar for infected PC and WON. Conclusion: PS was associated with a higher need for a second drainage procedure to achieve clinical success. The use of FCSEMS did not increase procedural costs for infected PC and WON.

Objectives: There is limited endosonographic literature regarding thyroid gland pathology, which is frequently visualized during upper endoscopic ultrasound (EUS). Our objective was to assess the prevalence of benign and malignant thyroid lesions encountered during routine upper EUS within a cancer center setting. Materials and Methods: The data were prospectively collected and retrospectively analyzed. All upper EUS procedures performed between October 2012 and July 2014 were reviewed at a large referral cancer center. Data collected included patient demographics, preexisting thyroid conditions, thyroid gland dimensions, the presence or absence of thyroid lesions, and EUS morphology of lesions if present, and interventions performed to characterize thyroid lesions and pathology results when applicable. Results: Two hundred and forty-five EUS procedures were reviewed. Of these, 100 cases reported a detailed endosonographic examination of the thyroid gland. Most of the thyroid glands were endosonographically visualized when the tip of the scope was at 18 cm from the incisors. Twelve cases showed thyroid lesions, out of which three previously undiagnosed thyroid cancers were visualized during EUS (two primary papillary thyroid cancers and one anaplastic thyroid cancer). Transesophageal EUS-guided fine needle aspiration of thyroid lesions was feasible when the lesion was in the inferior portion of the thyroid gland, and the tip of the scope was at 18 cm or more from the incisors. Conclusions: Routine EUS examination may detect unexpected thyroid lesions including malignant ones. We encourage endosonographers to screen the visualized portions of the thyroid gland during routine withdrawal of the echoendoscope.

Cystic lymphangioma of the colon (CLC) is a rare benign lesion that is usually asymptomatic and found incidentally during colonoscopy. Limitations in the conventional noninvasive diagnostic techniques have led to surgical resection of these lesions for diagnostic confirmation. Classic endoscopic ultrasound (EUS) findings of colonic cystic lymphangioma are submucosal anechoic cystic spaces with septations, intact muscularis propria, and no solid component. Patients who are asymptomatic with lesions having classic appearance as cystic lymphangioma with EUS can be observed without any intervention. We herein report a case of cystic lymphangioma of distal transverse colon in an asymptomatic patient diagnosed noninvasively using 20-MHz miniprobe EUS and managed conservatively without any surgical intervention.

Celiac artery (CA) stenosis is a relatively common finding in patients undergoing pancreaticoduodenectomy (PD). In the presence of CA stenosis, arterial blood supply to the celiac territory is usually sustained from the superior mesenteric artery (SMA) through well-developed collaterals. In this paper, the authors report endosonographically identified prominent gastroduodenal artery as the sign of CA stenosis for the first time. Uncovering previously unidentified vascular abnormality, endoscopic ultrasound (EUS) has improved patient management. The patient had uneventful collateral preserving PD.