Contrast-enhanced endoscopic ultrasonography

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest,to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures.We review the mechanisms of action of first,second and third generation contrast agents and their use in various endoscopic procedures in the gastrointestinal tract.Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy,assessment of depth of invasion of esophageal,gastric and gall bladder cancers and visualization of the portal venous system and esophageal varices.In addition,contrast agents can be used to differentiate pancreatic lesions.The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies.The sensitivity of power Doppler sonography to depict tumor neovascularization can be increased by contrast agents.Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion.In the future,these techniques could potentially be used to quantify tumor perfusion,to assess and monitor the efficacy of antiangiogenic agents,to assist targeted drug delivery and allow molecular imaging.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM:To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.METHODS:A retrospective study with prospectively entered database.From March 2012 to February 2013,a total of 21 patients(11 men)(mean age 64.2 years)with colon cancer beyond the rectum were recruited.The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum.Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.RESULTS:The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1min,respectively.The echoendoscope passed through the lesions in 13 patients(61.9%)and reached the cecum in 10 of 13 patients(76.9%).No adverse events were found.The lesions were located in the cecum(n=2),ascending colon(n=1),transverse colon(n=2),descending colon(n=2),and sigmoid colon(n=14).The accuracy rate for T1(n=3),T2(n=4),T3(n=13)and T4(n=1)were 100%,60.0%,84.6%and 100%,respectively.The overall accuracy rates for the T and N staging of colon cancer were 81.0%and52.4%,respectively.The accuracy rates among traversable lesions(n=13)and obstructive lesions(n=8)were 61.5%and 100%,respectively.endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0%and 68.4%,respectively.CONCLUSION:The echoendoscope is a feasible staging tool for colon cancer beyond rectum.However,accuracy of the echoendoscope needs to be verified by larger systematic studies.

An automated spring-loaded needle for endoscopic ultrasound-guided abdominal paracentesis in cancer patients

AIM: To evaluate the feasibility of using an automatedspring-loaded needle device for endoscopic ultrasound(EUS)-guided abdominal paracentesis(EUS-P) to see if this would make it easier to puncture the mobile and lax gastric wall for EUS-P.METHODS: The EUS database and electronic medical records at Fukushima Medical University Hospital were searched from January 2001 to April 2011. Patients with a history of cancer and who underwent EUS-P using an automated spring-loaded needle device with a 22-gauge puncture needle were included. The needle was passed through the instrument channel and advanced through the gastrointestinal wall under EUS guidance into the echo-free space in the abdominal cavity and ascitic fluid was collected. The confirmed diagnosis of malignant ascites included positive cytology and results from careful clinical observation for at least 6 mo in patients with negative cytology. The technical success rate, cytology results and complications were evaluated.RESULTS: We found 11 patients who underwent EUS-P with an automated spring-loaded needle device. In 4 cases, ascites was revealed only with EUS but not in other imaging modalities. EUS-P was done in 7 other cases because there was minimal ascitic fluid and no safe window for percutaneous abdominal aspiration. Ascitic fluid was obtained in all cases by EUS-P. The average amount aspirated was 14.1 mL(range 0.5-38 mL) and that was sent for cytological exam. The etiology of ascitic fluid was benign in 5 patients and malignant in 6. In all cases, ascitic fluid was obtained with the first needle pass. No procedure-related adverse effects occurred.CONCLUSION: EUS-P with an automated springloaded needle device is a feasible and safe method for ascites evaluation.

Large solitary ovarian metastasis from colorectal cancer diagnosed by endoscopic ultrasound

A case is presented of rectal carcinoma in which during staging by endoscopic ultrasound (EUS) a second large extrarectal mass was seen not otherwise visualized on computer tomograghy (CT) that was a solitary ovarian metastasis. The surgeon was alerted to the EUS f inding prior to the planned laparoscopic colectomy. On retro spective review of the CT pelvis after surgery, the radi ologist could still not diagnose the ovarian lesion sepa rated from the primary rectal tumor due to their close proximity. However, on EUS we were able to clearly see on real-time imaging that there was a distinct peri-recta mass apart from the primary rectal tumor.

Comprehensive review of diagnostic modalities for early chronic pancreatitis

Chronic pancreatitis(CP)is a progressive condition caused by several factors and characterised by pancreatic fibrosis and dysfunction.However,CP is difficult to diagnose at an early stage.Various advanced methods including endoscopic ultrasound based elastography and confocal laser endomicroscopy have been used to diagnose early CP,although no unified diagnostic standards have been established.In the past,the diagnosis was mainly based on imaging,and no comprehensive evaluations were performed.This review describes and compares the advantages and limitations of the traditional and latest diagnostic modalities and suggests guidelines for the standardisation of the methods used to diagnose early CP.