Intraductal ultrasound substantiates diagnostics of bile duct strictures of uncertain etiology

AIM:To report the largest patient cohort study investigating the diagnostic yield of intraductal ultrasound (IDUS) in indeterminate strictures of the common bile duct.METHODS:A patient cohort with bile duct strictures of unknown etiology was examined by IDUS.Sensitivity,specificity and accuracy rates of IDUS were calculated relating to the definite diagnoses proved by histopathology or long-term follow-up in those patients who did not undergo surgery.Analysis of the endosonographic report allowed drawing conclusions with respect to the T and N staging in 147 patients.IDUS staging was compared to the postoperative histopathological staging data allowing calculation of sensitivity,specificity and accuracy rates for T and N stages.The endoscopic retrograde cholangio-pancreatography and IDUS procedures were performed under fluoroscopic guidance using a side-viewing duodenoscope (Olympus TJF 160,Olympus,Ltd.,Tokyo,Japan).All procedures were performed under conscious sedation (propofol combined with pethidine) according to the German guidelines.For IDUS,a 6 F or 8 F ultrasound miniprobe was employed with a radial scanner of 15-20 MHz at the tip of the probe (Aloka Co.,Tokyo,Japan).RESULTS:A total of 397 patients (210 males,187 females,mean age 61.43 ± 13 years) with indeterminate bile duct strictures were included.Two hundred and sixty-four patients were referred to the department of surgery for operative exploration,thus surgical histopathological correlation was available for those patients.Out of 264 patients,174 had malignant disease proven by surgery,in 90 patients benign disease was found.In these patients decision for surgical exploration was made due to suspicion for malignant disease in multimodal diagnostics (computed tomography scan,endoscopic ultrasound or magnetic resonance imaging).Twenty benign bile duct strictures were misclassified by IDUS as malignant while 14 patients with malignant strictures were initially misdiagnosed by IDUS as benign resulting in sensitivity,specificity and accuracy ratesof 93.2%,89.5% and 91.4%,respectively.In the subgroup analysis of malignancy prediction,IDUS showed best performance in cholangiocellular carcinoma as underlying disease (sensitivity rate,97.6%) followed by pancreatic carcinoma (93.8%),gallbladder cancer (88.9%) and ampullary cancer (80.8%).A total of 133 patients were not surgically explored.32 patients had palliative therapy due to extended tumor disease in IDUS and other imaging modalities.Ninety-five patients had benign diagnosis by IDUS,forceps biopsy and radiographic imaging and were followed by a surveillance protocol with a follow-up of at least 12 mo;the mean follow-up was 39.7 mo.Tumor localization within the common bile duct did not have a significant influence on prediction of malignancy by IDUS.The accuracy rate for discriminating early T stage tumors (T1) was 84% while for T2 and T3 malignancies the accuracy rates were 73% and 71%,respectively.Relating to N0 and N1 staging,IDUS procedure achieved accuracy rates of 69% for N0 and N1,respectively.Limitations:Pretest likelihood of 52% may not rule out bias and overinterpretation due to the clinical scenario or other prior performed imaging tests.CONCLUSION:IDUS shows good results for accurate diagnostics of bile duct strictures of uncertain etiology thus allowing for adequate further clinical management.

How to perform gastrointestinal ultrasound: anatomy and normal findings

Gastrointestinal ultrasound is a practical, safe, cheap and reproducible diagnostic tool in inflammatorybowel disease gaining global prominence amongst clinicians. Understanding the embryological processes of the intestinal tract assists in the interpretation of abnormal sonographic findings. In general terms, the examination principally comprises interrogation of the colon, mesentery and small intestine using both lowfrequency and high-frequency probes. Interpretation of findings on GIUS includes assessment of bowel wall thickness, symmetry of this thickness, evidence of transmural changes, assessment of vascularity using Doppler imaging and assessment of other specific features including lymph nodes, mesentery and luminal motility. In addition to B-mode imaging, transperineal ultrasonography, elastography and contrast-enhanced ultrasonography are useful adjuncts. This supplement expands upon these features in more depth.

Instant evaluation of contrast enhanced endoscopic ultrasound helps to differentiate various solid pancreatic lesions in daily routine

BACKGROUND Contrast enhanced harmonic endoscopic ultrasound(CEH-EUS) is a spreading technique; some studies have shown its value in the diagnosis of pancreatic adenocarcinoma using quantitative analysis.AIM To examine the value of CEH-EUS for differentiating various pancreatic lesions in everyday routine with qualitative and quantitative analysis.METHODS Data of 55 patients with pancreatic lesions who underwent CEH-EUS were analysed retrospectively. Perfusion characteristics were classified by the investigator qualitatively immediately upon investigation, quantitative analysis was performed later on. Samples from fine needle aspiration(EUS-FNA) or surgical specimen served as gold standard.RESULTS CEH-EUS showed 39 hypoenhanced lesions, 3 non-enhanced and 13 hyperenhanced lesions. Concordance of the investigators qualitative classification of peak contrast enhancement with quantitative analysis later on was 100%, while other parameters such as arrival time, time to peak or area under the curve did not show additional value. 34 of 39 hypoenhanced lesions were pancreatic adenocarcinoma; of the hyperenhanced lesions 4 were inflammatory, 3 neuroendocrine carcinomas, 1 lymphoma, 1 insulinoma and 4 metastases(2 of renal cell carcinoma, 2 of lung cancer). Non-enhanced lesions showed up as necroses. Sensitivity for the detection of pancreatic adenocarcinoma was 100%,specificity 87.2% for hypoenhancement alone; in otherwise healthy pancreatic tissue all hypoenhanced lesions were pancreatic adenocarcinoma(sensitivity and specificity 100%, PPV and NPV for adenocarcinoma 100%).CONCLUSION This study again shows the excellent value of CEH-EUS in everyday routine for diagnostics of various focal pancreatic lesions suggesting that qualitatively assessed hypoenhancement is highly predictive for adenocarcinoma. Additional quantitative analysis of perfusion parameters does not add diagnostic yield. In case of the various hyperenhanced pancreatic lesions in our data set, histologic sampling is essential for further treatment.