Second generation optical coherence tomography: Preliminary experience in pancreatic and biliary strictures

IntroductionEvaluation of indeterminate biliary strictures remains a diagnostic challenge. Optical coherence tomography (OCT) provides in-vivo, wide-field, cross-sectional imaging at the microstructure level. We present the first preliminary data using a second-generation OCT system using volumetric laser endomicroscopy (VLE) in biliary and pancreatic duct strictures.Methods10 consecutive patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and OCT for indeterminate biliary or pancreatic stricture evaluation were captured in a registry. Following ductal cannulation and guidewire placement, an imaging probe was advanced into the duct and images were interpreted in-vivo. Tissue sampling with cytology brushing was performed in all cases. Demographics, procedural information, imaging data, and histologic findings were collected.Results8 had biliary strictures and 2 had pancreatic duct strictures. VLE was successfully performed in all patients (100%). Histology revealed malignancy in 3 patients (cholangiocarcinoma) and benign disease in the remaining 7 patients, including 1 with primary sclerosing cholangitis (PSC). All 3 cholangiocarcinoma patients demonstrated epithelial thickening with projections, a hyper-reflective surface with shadowing, and layering effacement (loss of visualization and haziness of inner mucosal layers). A PSC patient showed onion skin layering and hyper-reflective sub-surface structures but with preserved wall layering. Benign biliary strictures showed clearly delineated epithelial layer and clear layering in the inner mucosal layers as well as the presence of dilated hypo-reflective structures.ConclusionThere may be characteristic VLE findings for malignant, inflammatory, and benign biliary strictures.     

Optical coherence tomography to detect epithelial lesions of the main pancreatic duct: an Ex Vivo study

BACKGROUND: Optical coherence tomography (OCT) permits high-resolution, real-time, infrared-generated imaging of tissue microstructures by a probe inserted through the endoscope operative channel. Resolution is approximately 10 microm and the penetration depth of the near-focus probe is about 1 mm. The probe can be inserted into the main pancreatic duct (MPD) through a standard endoscopic retrograde cholangiopancreatography catheter. AIMS AND METHODS: To assess the ability of OCT to identify the structure of the MPD, to distinguish normal and malignant MPD epithelium, and to assess intra- and interobserver reproducibility of OCT images. Multiple sections of neoplastic and non-neoplastic segments of 10 consecutive surgical pancreatic specimens were obtained from patients with pancreatic head adenocarcinoma who had undergone Whipple resection, and repeated OCT radial and longitudinal scanning was done within 1 h of resection and before pathological examination. We compared 249 good-quality images with 100 histopathological sections. RESULTS: OCT recognized a definite, different pattern in 82.9% of tumor-free and in 97.6% of tumor-involved specimens; sensitivity and specificity for discrimination between adenocarcinoma and normal tissue were 78.6% and 88.9%, respectively. Inflammatory and dysplastic changes of the MPD showed an OCT pattern similar to that of the normal tissue in 53.3% of images. Overall, intraobserver reproducibility ranged from 85.1% to 100% and interobserver reproducibility ranged from 69.9% to 100% and from 89.7% to 100% for tumor-free and tumor-involved segments, respectively. CONCLUSIONS: OCT identified the neoplastic and non-neoplastic MPD layer structure and appeared to be a reproducible technique. In non-neoplastic conditions, OCT appeared unable to differentiate between normal and abnormal tissues in about half of the cases.     

Value of exfoliative cytology for investigating bile duct strictures.

The cause of a biliary tract stricture may be difficult to determine radiologically. Exfoliative biliary cytology was evaluated in 62 patients (median age 65 years, range 30-94) with biliary tract strictures presenting to the Hepatobiliary Unit between January 1984 and December 1989. Bile samples were taken during endoscopic retrograde cholangiopancreatography (ERCP) in 42 patients, percutaneous cholangiography in 14, and both in six. The site of stricturing was upper third of the bile duct in 43% (n = 27), middle third in 10% (n = six), and lower third in 47% (n = 29). Of the 47 patients with radiological appearances of a malignant stricture, 22 (47%) had histological confirmation by biopsy either under computed tomography guidance, at endoscopy, at operation, or at necropsy. Fourteen of the 47 patients had positive cytology (30%). In seven patients cytology alone established the presence of malignancy (15%) and in the other seven positive cytology was confirmed by histology. The addition of cytology to tissue biopsy therefore allowed malignancy to be confirmed in 29 of the 47 patients (62%). None of the 15 patients subsequently shown to have benign disease had positive cytology. Sensitivity of the technique was 30% and specificity 100%. Samples for exfoliative cytology are simple to obtain, the results are highly specific and should be a routine part of the investigation of biliary strictures.     

Left main dissection conservatively managed with optical coherence tomography guidance

Left main dissection (LMD) is a rare but feared complication of cardiac catheterization. It is usually managed by bailout stent implantation or coronary artery bypass surgery. We describe a case of iatrogenic, retrograde LMD during percutaneous coronary intervention. After covering the retrograde entry of the dissection in the ostial left anterior descending artery (LAD), optical coherence tomography (OCT) showed, that there was no antegrade entry in the left main and that the minimal true lumen area in the left main was 7.2 mm². It was therefore decided to treat the LMD conservatively and reassess the results by angiography 6 months later. At follow‐up angiography, no stenosis or residual dissection in the left main were noted. The patient was doing fine at 1‐year follow‐up. OCT is a valuable tool for assessing coronary artery dissections and may guide the decision, whether to stent or not to stent a dissection. In selected cases LMD may be managed conservatively. © 2013 Wiley Periodicals, Inc.     

Intraductal tubular carcinoma in an adenoma of the main pancreatic duct of the pancreas head

A 50-year-old woman presented with intermittent diarrhea and upper abdominal pain. Laboratory data showed elevated serum amylase and elastase-I levels. Further image studies revealed a small, well-defined nodular lesion (8 mm in diameter) without mucin hypersecretion in the main pancreatic duct (MPD) of the pancreatic head and subsequent dilatation of the distal main pancreatic duct. A pylorus-preserving pancreatoduodenectomy with regional lymphadenectomy was performed. Microscopically, the tumor was an intraductal tubular carcinoma (ITC) in a tubular adenoma, suggesting direct histologic evidence of the adenoma–carcinoma sequence in intraductal tubular tumors, differing from previous reports of ITCs describing de novo-like development. The prognosis for ITC patients is sometimes dismal; therefore, early detection and appropriate surgical resection are mandatory to achieve long-term survival in ITC patients. MPD dilatation is a crucial sign and clue enabling the early detection of tiny pancreatic tumors.     

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     

Clinical significance of main pancreatic duct dilation on computed tomography： Single and double duct dilation

AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful followup since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.     

Cystic duct directly joining the main pancreatic duct

A unique anomaly of the direct union between the cystic duct and the main pancreatic duct is presented. A 19-year-old man with a history of repeated epigastralgia underwent endoscopic retrograde cholangiopancreaticography that showed a direct union between the cystic duct and the main pancreatic duct. No pancreaticobiliary maljunction was noticed. Cholecystectomy accompanied by resection of the long cystic duct was performed. The excised gallbladder showed cholesterolosis, chronic cholecystitis, and hyperplasia of the pseudopyloric glands microscopically. The patient has been well for 3 years since surgery.     

Main pancreatic duct, common bile duct and sphincter of Oddi structure visualized by optical coherence tomography: An ex vivo study compared with histology

BACKGROUND: Optical coherence tomography has been proposed to obtain high-resolution imaging of tissue structure of GI tract. Up till now, the optical coherence tomography appearance of the common bile duct, main pancreatic duct and sphincter of Oddi wall structure has not yet been defined. AIMS: To compare, in a prospective study, optical coherence tomography images of pancreato-biliary ductal system with histology and identify the optical coherence tomography pattern of the normal wall structure of the ducts. METHODS: Multiple sections of non-neoplastic segments of five consecutive ex vivo human pancreatic specimens were investigated by optical coherence tomography scanning within 1h of resection. Sixty optical coherence tomography images were compared with the corresponding histological findings. RESULTS: Optical coherence tomography appearance of normal common bile duct, main pancreatic duct and sphincter of Oddi is characterized by a differentiated three-layer architecture with a regular surface and a homogeneous back-scattered signal, corresponding to the single layer of epithelial cells, the connective-muscular layer and the muscular or acinar structure, respectively. Optical coherence tomography and histology findings were concordant in all cases. CONCLUSIONS: Optical coherence tomography was able to provide in real-time images of wall structure of the normal common bile duct, main pancreatic duct and sphincter of Oddi that are similar to those obtained by histology. These results suggest that optical coherence tomography could enable high-resolution images to be obtained from the pancreato-biliary system during an ERCP procedure.     

腔内射频消融治疗胆管恶性狭窄的初步研究

目的 探讨内镜下应用腔内射频消融技术姑息性治疗胆管恶性狭窄的安全性及可行性.方法 前瞻性选取胆管恶性梗阻无法手术切除的12例患者实施ERCP,在胆管插管成功后,循导丝导入专用双极射频电极,于肿瘤部位进行射频烧灼,然后留置胆道支架,观察术后恢复情况并密切随访.结果 所有患者均成功完成射频消融治疗并留置胆道支架(塑料支架6例,金属支架6例,其中3例患者同期放置胰管支架).出现胆管炎1例,胰腺炎1例,均短期保守治疗控制.黄疸迅速缓解率为58.3％ (7/12);平均随访3.4个月(0.5 ～5.5个月),1个月末支架通畅率为100％ (12/12),3个月末通畅率为80％ (8/10);1例患者死于心脑血管意外,其余患者均存活无特殊不适.结论 对于胆管恶性狭窄,经内镜进行腔内射频治疗是安全可行的,初步疗效满意,但远期疗效及最佳治疗方案仍有待进一步探讨.     

In vivo optical coherence tomography imaging of the pancreatic and biliary ductal system

BACKGROUND: In vivo optical coherence tomography (OCT) imaging has not yet been applied to the pancreatic ductal system. The aim of this study was to obtain in vivo OCT images of dog pancreatic and biliary ducts, and to correlate the images with histology. METHODS: Images of dog pancreatic and biliary ducts were obtained by using an in vivo OCT probe introduced through the respective papillary orifices. Each duct was imaged in multiple locations, and the site of imaging was marked with injected India ink. After imaging, the dogs were euthanized, and the pancreaticobiliary system was harvested. Histologic cross sections were correlated with in vivo OCT images by measuring the structures seen on in vivo OCT images and correlating them with structures seen on corresponding histology slides that contained India ink. OBSERVATIONS: Eighteen pairs of in vivo OCT images and histology slides from the bile duct and the pancreatic duct were obtained from 5 dogs. The entire duct wall could be visualized. A low reflective in vivo OCT layer corresponding to the epithelium could be discerned on many images. The bile duct showed a more complex architecture and had greater variations within the reflective OCT layers, possibly because of greater cellularity within the lamina propria. Nuclei within cells could not be identified, and structures adjacent to the ducts could not be imaged. CONCLUSIONS: In vivo OCT is capable of imaging the pancreaticobiliary ductal system and of identifying the epithelial layer. Because of limited depth of imaging (320-845 micron), OCT is unlikely to serve the purpose of tumor staging.     

Techniques and best practices for optical coherence tomography

Optical coherence tomography (OCT) is a novel intracoronary imaging modality that utilizes near‐infrared light to provide information regarding lesion length and severity, vessel lumen diameter, plaque morphology, as well as the opportunity for stent procedure guidance and follow‐up. While analogous to intravascular ultrasound (IVUS), the specific imaging properties, including significantly higher resolution, and technical specifications of OCT offer the ability for intracoronary diagnostic and interventional procedure guidance roles that require a thorough understanding of the technology. We provide coronary interventionalist's a user's guide to OCT, focusing on techniques and approaches to optimize imaging, with a focus on efficiency, safety and strategies for effective imaging. © 2014 Wiley Periodicals, Inc.     

Optical coherence tomography and Doppler optical coherence tomography in the gastrointestinal tract

Optical coherence tomography(OCT) is a noninvasive,high-resolution,high-potential imaging method that has recently been introduced into medical investigations.A growing number of studies have used this technique in the field of gastroenterology in order to assist classical analyses.Lately,3D-imaging and Doppler capabilities have been developed in different configurations,which make this type of investigation more attractive.This paper reviews the principles and characteristics of OCT and Doppler-OCT in conn...     

3D-OCT优化处理左主干四分叉病变1例

正1对象和方法1.1对象患者男性,43岁,主因发作性胸痛1个月于2017年2月入院。患者于2017年1月出现胸骨后疼痛,向左肩部放射,伴大汗,休息后不能缓解。当地医院诊断为急性心肌梗死,并行冠脉造影检查,提示左主干分叉病变,为进一步诊治遂来我院。否认高血压病、糖尿病病史,既往吸烟20余年,20支/d。入院查体:血压100/60 mm Hg(1 mm Hg=0.133 k Pa),心率64次/min,律齐,心音尚可,各瓣膜听诊区未闻及病理性杂音,余各器官查     

Clinical applications of optical coherence tomography

Rupture of vulnerable plaque (VP) is responsible for most coronary events. Optical coherence tomography (OCT) is a high-resolution imaging method that allows excellent characterization of atherosclerotic plaque. While this technique is limited by the need to interrupt blood flow and a shallow depth of penetration, its resolution is an order of magnitude greater than possible with intravascular ultrasound (IVUS), and it has demonstrated better sensitivity and specificity for accurately determining plaque composition. Early in vitro and in vivo experiences have affirmed the excellent quality of these images making it an attractive technology for the analysis of VP. Its high resolution likely renders it the best imaging modality currently available for the evaluation of proper stent deployment and of intracoronary pathology in the setting of percutaneous coronary interventions (PCI). Our institution is currently involved in a multicenter trial to evaluate the effectiveness of OCT when compared to IVUS in this setting. Ongoing technological improvements aim to permit rapid scanning which should alleviate its current major limitation of needing to scan in a blood-free space. OCT is a promising new technology in the evaluation of atherosclerotic plaque and coronary microstructure.