Malignant Strictures Research Articles

A narrative review of progress in airway stents.

Background and ObjectiveAirway stents, used to restore airway patency, are mostly utilized by patients with malignant airway strictures, and are occasionally used in a range of other airway related diseases, including conditions which result in benign stenosis, malacia, and fistula. There has been an increasing number of airway stents that are being developed thanks to improvements in interventional therapy. However, the method of promoting airway stents for clinical application remains undetermined. Herein, we describe the recent advances in airway stents by reviewing the published studies, providing the reference for clinical decision-making and further research on airway stents.MethodsRelevant articles between January 1964 and November 2021 were obtained from PubMed, Web of Science, and EMBASE databases. The terms “metallic”, “silicone”, “drug-eluting", “biodegradable”, “radioactive”, “three-dimensional (3D)”, and “stents” were searched in different combinations.Key Content and FindingsIn this review, we focus on the latest evidence in terms of the application of various stents with novel materials and designs including novel metallic, novel silicone, drug-eluting, biodegradable, radioactive, and 3D stents for airway stenosis. Despite reducing the well-known complications of all current commercially available stents, novel stents are still in their infancy without a long track record of utility and safety, and remain some limitations. There are more steps to be taken before such stents enter routine clinical practice.ConclusionsA combination of 3D-printing method and biodegradable material may present a promising avenue of solving the existing problems pertaining to “classic” stents and has potential to become the main trend in the future.

Antibody array-based proteomic screening of novel biomarkers in malignant biliary stricture.

Distinguishing between benign and malignant bile duct strictures has long been a diagnostic challenge in clinical practice. This study aimed to discover novel biomarkers in bile to improve the diagnostic accuracy of malignant biliary strictures. Bile samples were collected from 6 patients with malignant or benign biliary stricture, respectively. Protein profiles of the bile were analyzed with a semi-quantitative human antibody array of 440 proteins. Then the differential expressed proteins were screened by Venn diagram analysis. Following this, the accuracy of these potential biomarkers for discriminating between malignant and non-malignant biliary strictures was validated in a larger (n= 40) group of patients using ROC analysis and the best biomarker combination was further selected by lasso analysis. Twenty proteins were found differentially expressed in malignant versus benign biliary strictures, 6 of which were identified by Venn diagram analysis to be up-regulated regardless of the location of biliary strictures. Among the 6 biomarkers, bile lipocalin-2, P-cadherin, and adipsin showed better diagnostic utility than that of bile CA19-9. Lasso analysis identified that lipocalin-2, P-cadherin and CA19-9 as a group of makers best distinguished malignant from benign strictures. Lipocalin-2 and P-cadherin measurements in bile could be clinically useful for the detection of malignant biliary strictures.

Emergency Surgery in a Regional Hospital Before and During the COVID 19 Pandemic

Background In extraordinary situations the volume of work of all hospital services changes. The impact of the global COVID 19 pandemic, is classified as an international emergency situation. But, we do not know How did one regional hospital in Bosnia and Herzegovina cope with the COVID-19 pandemic in line with its capacities in terms of emergency surgery. Materials and Methods We used data from our surgical protocols – emergency surgery performed in our department during July and August in 2019 and 2020. We used descriptive statistics. Results: The total number of examinations in the emergency surgical clinic was almost the same. The number of admissions in the period in question in 2020 was 36% lower in relation to the control period. The total number of operations was 17% lower. The number of emergency operations was 39.3% lower. Conclusion: it may be said that emergency surgery functioned on a satisfactory level in our regional hospital, and that the results do not deviate significantly from data from the literature, except regarding emergency amputations and emergency surgery for malignant colorectal stenosis.

Endoscopic Ultrasound Plus Endoscopic Retrograde Cholangiopancreatography Based Tissue Sampling for Diagnosis of Proximal and Distal Biliary Stenosis Due to Cholangiocarcinoma: Results from a Retrospective Single-Center Study.

Simple SummaryThe diagnosis of cholangiocarcinoma depends on several factors, including growth pattern and location. Previous studies have evaluated the diagnostic accuracy of endoscopic retrograde cholangiopancreatography based tissue sampling and endoscopic ultrasound with either fine-needle aspiration or fine-needle biopsy, reporting values < 80% for each procedure. Here, we describe the performance of both methods in a group of patients with a stricture of the biliary tract suspicious for cholangiocarcinoma. Our analysis confirms the high diagnostic accuracy of the procedures when performed together in distinguishing between a primary malignant or benign biliary stenosis. Differentiating between benign and malignant biliary stenosis (BS) is challenging, where tissue diagnosis plays a crucial role. Endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling and endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) or biopsy (FNB) are used to obtain tissue specimens from BS. The aim of this retrospective study was to evaluate the diagnostic yield of EUS-FNA/B plus ERCP with brushing or forceps biopsy in BS. All endoscopic procedures performed in patients with BS at our gastroenterology unit were reviewed. The gold standard for diagnosis was histopathology of surgical specimens or the progression of the malignancy at radiological or clinical follow-up. A total of 70 endoscopic procedures were performed in 51 patients with BS. Final endoscopic diagnosis was reached in 96% of the patients and was malignant in 61.7% and benign in 38.3% of cases. Sensitivity, specificity, and diagnostic accuracy were 73.9%, 100%, and 80%, respectively, for EUS-FNA/B; 66.7%, 100%, and 82.5% for ERCP; and 83.3%, 100%, and 87.5% for both procedures carried out in the same session. The combination of EUS and ERCP tissue sampling seems to increase diagnostic accuracy in defining the etiology of BS. Performing both procedures in a single session reduces the time required for diagnostic work-up and optimizes resources.

Gastric Outlet Obstruction: Current Status and Future Directions.

Gastric outlet obstruction (GOO) is a relatively common condition in which mechanical obstruction of the pylorus, distal stomach, or duodenum causes severe symptoms such as nausea, vomiting, abdominal pain, and early satiety. Its etiology includes both benign and malignant disorders. Currently, GOO has many treatment options, including initial conservative therapeutic protocols and more invasive procedures, such as surgical gastroenterostomy, stent placement and, the most recently implemented procedure, endoscopic ultrasound-guided gastroenterostomy (EUS-GE). Each procedure has its merits, with surgery often prevailing in patients with longer life expectancy and stents being used most often in patients with malignant gastric outlet stenosis. The newly developed EUS-GE combines the immediate effect of stents and the long-term efficacy of gastroenterostomy. However, this novel method is a technically demanding process that requires expert experience and special facilities. Thus, the true clinical effectiveness, as well as the duration of the effects of EUS-GE, still need to be determined.

Impact of a shorter replacement interval of plastic stents on premature stent exchange rate in benign and malignant biliary strictures.

The main disadvantage of plastic stents is the high rate of stent occlusion. The usual replacement interval of biliary plastic stents is 3months. This study aimed to investigate if a shorter interval of 6-8weeks impacts the median premature exchange rate (mPER) in benign and malignant biliary strictures. All cases with endoscopic retrograde cholangiopancreatography (ERCP) and plastic stent placement were retrospectively analyzed since establishing an elective replacement interval of every 6-8weeks at our institution and mPER was determined. A total of 3979 ERCPs (1199 patients) were analyzed, including 1262 (31.7%) malignant and 2717 (68.3%) benign cases, respectively. The median stent patency (mSP) was 41days (range 14-120) for scheduled stent exchanges, whereas it was 17days (1-75) for prematurely exchanged stents. The mPER was significantly higher for malignant (28.1%, 35-50%) compared with benign strictures (15.2%, 10-28%), P<0.0001, respectively. mSP was significantly shorter in cases with only one stent (34days [1-87] vs 41days [1-120]) and in cases with only a 7-Fr stent (28days [2-79]) compared with a larger stent (34days [1-87], P=0.001). Correspondingly, mPER was significantly higher in cases with only one stent (23% vs 16.2%, P<0.0001) and only a 7-Fr stent (31.3% vs 22.4%, P=0.03). A shorter replacement interval does not seem to lead to a clinically meaningful reduction of mPER in benign and malignant strictures. Large stents and multiple stenting should be favored as possible.

Use of catheter-based cholangioscopy in the diagnosis of indeterminate stenosis: a multicenter experience.

Direct bile ducts visualization through cholangioscopy has gained popularity due to its better diagnostic accuracy than a standard ERCP in indeterminate biliary stricture. We aimed to review our catheter-based cholangioscopy interventions in patients with indeterminate biliary stenosis, using the SpyGlass Direct Visualization System (SDVS) and summarize our experience in terms of procedures and results. We collected 25 consecutive patients with indeterminate biliary stricture over 3 years. The overall procedural success in our cohort amounted to 96% (24/25). If we focus on the diagnostic procedures, the ability to merely visualize the region of interest/lesion and perform biopsy of the lesion was possible in 96% (24/25) In our cohort localization in the common bile duct (P=0.03; 95% CI: 0.27-0.96) was found as positive determining factor for diagnosis. Sensitivity, specificity and accuracy for visual diagnosis by SDVS in our cohort were 100, 83.3 and 96%, respectively. The use of biopsy or obtaining a histological diagnosis to assist in identifying patients with malignant stenosis, to exclude malignancy and to correctly classify diagnosed patients resulted in a sensitivity of 100%, a specificity of 73% with an overall accuracy of 94.4%. Only a mild adverse event (cholangitis, treated conservatively) occurred. Today, the SDVS should be considered essential in diagnosing indeterminate biliary strictures, since the procedure is associated with high procedural success in terms of diagnostic accuracy, alters clinical outcome in over 80% of considered insolvable cases, with an acceptable safety profile.

Role of magnetic resonance cholangiopancreatography in conjunction with 3D assessment in patients of different billiary obstruction causes

Background: Conventional 2d MRCP has pitfalls which may stimulate or mask various pathologic conditions of extrahepatic ducts or pancreatic duct, to overcome this a number of new modern techniques are being used.Methods: Observational study carried out in Government Medical College Srinagar including a total of 50 patients.Results: Gallstone disease was the most common etiology responsible for biliary obstruction. Both Malignant and Benign strictures, IHBR dilatation and pancreatic duct dilatation were better appreciated by 3D MRCP than 2D MRCP.Conclusions: In patients with biliary obstruction, MRCP aims at finding the pathology. It also helps in planning of surgical or interventional management and serves to guide these procedures with 3D MRCP definitely having advantages.

Central airway obstruction treatment with self-expanding covered Y-carina nitinol stents: A single center retrospective analysis.

BackgroundCentral airway obstruction (CAO) is one of the most challenging, potentially lethal complications in malignant and benign respiratory diseases. Worsening dyspnea is also a relevant cause for reduced quality of life in such patients. Here, we present our data on the application of covered, self‐expanding Y‐carina nitinol stents due to benign and malignant diseases.MethodsWe retrospectively identified 27 patients who had undergone 31 rigid bronchoscopies with implantation of covered Y‐carina nitinol stents over a period of 10 years in order to evaluate indication, clinical course, and outcome.ResultsShort‐term survival of successfully stented patients with palliative and curative treatment goal did not differ, allowing for diagnosis independent indication. With respect to overall survival, patients with endoluminal obstruction benefited most compared to patients with fistula and/or external compression. Granulation tissue formation (61.3%) and mucus plugging (80.6%) were the most frequent complications. Material defect (6.5%) and migration (3.2%) were rare complications that could be handled by revisional rigid bronchoscopy and stent exchange in some cases.ConclusionsImplantation of self‐expanding covered Y‐carina nitinol stents via rigid bronchoscopy is a feasible and safe treatment option for benign and malignant central airway obstruction. Especially in palliative, malignant airway stenosis, stenting might facilitate additional treatment options and optimize dyspnea and eventually quality of life.

Diagnostic accuracy of endoscopic ultrasound in evaluation of patients with obstructive jaundice: single-center experience

Background/aimsWe prospectively evaluated the role of endoscopic ultrasound (EUS) in detecting the cause of common bile duct (CBD) dilatation in patients in whom trans-abdominal ultrasound (TUS) could not demonstrate the cause of dilation as a proper second step in the diagnostic workup of patients with obstructive jaundice compared to magnetic resonance cholangiopancreatography (MRCP).MethodsThis study was conducted on patients with obstructive jaundice admitted to the inpatient ward or the outpatient endoscopy unit of Theodor Bilharz Research Institute (TBRI) during the period between January 2019 and August 2019. A patient with obstructive jaundice and TUS showed CBD dilatation with internal diameter ≥ 7 mm and biliary stricture.ResultsDuring the period between January 2019 and August 2019, 136 were recruited; 8 patients who were pregnant and 3 patients who had gastric bypass surgery were excluded. Sixty-five patients were diagnosed confidently by TUS as biliary stones and were excluded from the analysis. Sixty patients with obstructive jaundice and indefinite etiology on TUS were included in the final analysis. The final diagnosis of patients was 38 patients (63.33%) of malignant etiology [26 pancreatic cancer (43.33%), 4 cholangiocarcinoma (6.66%), and 8 with ampullary cancer (13.33%)] and 22 patients (36.67%) of benign etiology [10 calcular obstruction (16.66%), 8 benign stricture (13.33%), and 4 pancreatitis (6.66%)]. The sensitivity and specificity values for malignant stricture detected by EUS were 100% and 86.36%, respectively, with positive predictive value of 92.68%, negative predictive value of 100%, and accuracy of 95%, while MRI showed 82.14% sensitivity and 25% specificity with positive predictive value of 79.31 and accuracy of 69.4%. EUS supported correct diagnosis in 57 patients (95%: CI 86.08 to 98.96%) while MRI did it in 36 patients (69.44%: CI 51.89% to 83.65%).Only 43 (71.7%) patients needed endoscopic retrograde cholangiopancreatography (ERCP) for management of obstructive jaundice, sparing 17 patients (28.3%) unnecessary invasive procedures.ConclusionsEUS is a minimally invasive method with low incidence of complications with high diagnostic accuracy in patients with dilated CBD and normal MRCP.

A self-expandable C-shaped 3D printing tracheal stent for combinatorial controlled paclitaxel release and tracheal support

Current tracheal stents palliatively relieve malignant tracheal stenosis but cannot treat the tumor, resulting in the occurrence of restenosis due to tumor progressive over-growth. Moreover, the stents block the entire tracheal mucosa contact with them and thus prevent mucus/sputum discharge, causing an airway blockage. In order to overcome those shortcomings, we study a novel self-expandable C-shaped tracheal stent loaded with paclitaxel (PTX), which consists of an inner poly (ε-caprolactone) layer, a middle Fe3O4 magnetic nanoparticles loaded poly (ε-caprolactone) layer and an outer PTX-loaded ethylene-vinyl acetate copolymer layer containing phase-change 1-hexadecanol. The C-shaped tracheal stents are easily fabricated on a roller by using a self-made specific three-dimensional printer. It is found that the stents present unidirectional PTX release, good self-expanding and appropriate trachea supporting properties, and generate heat to raise temperature under an alternating magnetic field, which facilitates temperature-responsive PTX release and permeation in tracheal tissue. The stents have good biosafety in rabbits and keep airway patency for the investigated period (1 month) without the occurrence of mucus/sputum blockage after implantation in rabbit trachea. This study provides a scientific basis for the development of novel self-expandable C-shaped tracheal stents with combinatorial tracheal support and local chemotherapy.

Endoscopic stenting for stenosing cancer and digestive canal structures

Background. The purpose of the work was to evaluate the effectiveness of the endoscopic stenting method in stenosing cancer and strictures of the digestive tract. Materials and methods. Since January 2015, endoscopic stenting has been performed in 12 patients using self-expanding nitinol stents with/without polymer coating manufactured by Boston Scientific, Ltd (USA) and uncoated nitinol stents manufactured by Garson (Korea). The study included 8 men (66.7 %) and 4 women (33.3 %) aged 51–80 years, (63.0 ± 4.2) years on average. Stenosing esophageal cancer was diagnosed in 5 patients, stenosing cancer of the gastric outlet— in 3, stenosing duodenal cancer — in one, esophageal stricture — in 3 people. In all patients, the indication for stenting was impaired patency of the digestive tract due to the underlying di-sease. Results. Nutrition was restored in all patients. In the group of stenosing esophageal cancer, the 30-day mortality rate was 20%, the median survival rate was 9 months. Recurrence of dysphagia was diagnosed in one person, recanalization of the stent lumen was performed. In the group with stenosing cancer of the gastric outlet and duodenum, the 30-day mortality rate was 33.3%, the median survival rate was 11 months. Impaired gastric emptying was detected in one patient, repeated stent-to-stent stenting was performed. In the group with esophageal stricture, one individual had stent migration, so the stent was repositioned. Conclusions. Endoscopic stenting with self-expanding nitinol stents in incurable patients with malignant stenoses of the esophagus, stomach, duodenum and in those with benign esophageal strictures is the surgery of choice, a safe and effective method that allows you to restore and continue natural nutrition and thereby improve the quality of life in incurable cases. Complications arising in the late period after stenting were found in 25 % of patients, and were corrected endoscopically.

Diagnostic Value of Endoscopic Ultrasonography for Common Bile Duct Dilatation without Identifiable Etiology Detected from Cross-Sectional Imaging.

Background/AimsEndoscopic ultrasonography (EUS) is warranted when cross-sectional imaging demonstrates common bile duct (CBD) dilatation without identifiable causes. This study aimed to assess the diagnostic performance of EUS in CBD dilatation of unknown etiology. MethodsRetrospective review of patients with dilated CBD without definite causes undergoing EUS between 2012 and 2017. ResultsA total of 131 patients were recruited. The mean age was 63.2±14.1 years. The most common manifestation was abnormal liver chemistry (85.5%). The mean CBD diameter was 12.2±4.1 mm. The area under the receiver operating characteristic curve (AUROC) of EUS-identified pathologies, including malignancy, choledocholithiasis, and benign biliary stricture (BBS), was 0.98 (95% confidence interval [CI], 0.95-1.00). The AUROC of EUS for detecting malignancy, choledocholithiasis, and BBS was 0.91 (95% CI, 0.85-0.97), 1.00 (95% CI, 1.00-1.00), and 0.93 (95% CI, 0.87-0.99), respectively. Male sex, alanine aminotransferase ≥3× the upper limit of normal (ULN), alkaline phosphatase ≥3× the ULN, and intrahepatic duct dilatation were predictors for pathological obstruction, with odds ratios of 5.46 (95%CI, 1.74-17.1), 5.02 (95% CI, 1.48-17.0), 4.63 (95% CI, 1.1-19.6), and 4.03 (95% CI, 1.37-11.8), respectively. ConclusionsEUS provides excellent diagnostic value in identifying the etiology of CBD dilatation detected by cross-sectional imaging.

Percutaneous transhepatic management of biliary strictures in patients with dysfunctioning plastic biliary endoprostheses.

To evaluate the safety and outcomes of percutaneous transhepatic management of dysfunctioning plastic biliary endoprostheses (PBE) in patients with benign/malign biliary strictures. Twenty-nine patients (22 men, 7 women; mean age of 60.7 (range 33-88) years) diagnosed with dysfunctioning PBE were included. Percutaneous transhepatic biliary drainage and subsequent PBE dislodgment into the bowel were performed in all cases. Patient demographics, etiology of the biliary stricture, indication, technical success, complications, and clinical outcomes were gleaned from medical records. Seventeen patients had malignant strictures, while 12 patients had benign conditions. A total of 36 PBE (33 straight, 3 double-J) were treated. Six patients had more than one PBE. Successful dislodgement of the PBE was achieved in 28 (96.6%) of the cases. Monorail threading was performed in 8 cases while dislodgement by balloon friction was utilized in 21 patients. There was no statistical significance between benign and malignant biliary strictures regarding dislodgement duration (p = 0.080). No major complication was encountered. Thirteen minor complications in 10 patients including abdominal pain (n = 8) and mild hemobilia (n = 5) were observed and treated conservatively. Uneventful passage of the PBE was reported by all patients with technical success. Percutaneous transhepatic methods aid as a reasonable alternative in the treatment of benign and malignant biliary strictures in patients with dysfunctioning PBE when endoscopic approaches fail or are not eligible.

Effect of Stent Placement on Survival in Patients with Malignant Portal Vein Stenosis: A Propensity Score–Matched Study

ObjectivePercutaneous portal vein (PV) stent placement can be an effective treatment for symptoms associated with portal hypertension. This study aimed to evaluate the effect of PV stenting on the overall survival (OS) in patients with malignant PV stenosis.Materials and MethodsTwo groups of patients with malignant PV stenosis were compared in this retrospective study involving two institutions. A total of 197 patients who underwent PV stenting between November 2016 and August 2019 were established as the stent group, whereas 29 patients with PV stenosis who were treated conservatively between July 2013 and October 2016 constituted the no-stent group. OS was compared between the two groups before and after propensity score matching (PSM). Risk factors associated with OS were evaluated using the Cox proportional hazards model. Procedure-associated adverse events were also evaluated.ResultsThe stent group finally included 100 patients (median age, 65 [interquartile range, 58–71] years; 64 male). The no-stent group included 22 patients (69 [61–75] years, 13 male). Stent placement was successful in 95% of attempted cases, and the 1- and 2-year stent occlusion–free survival rate was 56% (95% confidence interval, 45%–69%) and 44% (32%–60%), respectively. The median stent occlusion–free survival time was 176 (interquartile range, 70–440) days. OS was significantly longer in the stent group than in the no-stent group (median 294 vs. 87 days, p < 0.001 before PSM, p = 0.011 after PSM). The 1- and 3-year OS rates before PSM were 40% and 11%, respectively, in the stent group. The 1-year OS rate after PSM was 32% and 5% in the stent and no-stent groups, respectively. Anemia requiring transfusion (n = 2) and acute thrombosis necessitating re-stenting (n = 1) occurred in three patients in the stent group within 1 week.ConclusionPercutaneous placement of a PV stent may be effective in improving OS in patients with malignant PV stenosis.

Changes in Pulmonary Function Test Results and Respiratory Symptoms before and after Airway Stent Removal.

Airway stenting is a useful form of palliation for patients with airway stenosis/fistulas; the stent can be removed after addressing the cause of the airway disorder. Patients with airway stents often complain of coughing and difficulty with expectoration, so the use of such stents can negatively affect pulmonary function and worsen symptoms. The aim of this study was to compare pulmonary function and respiratory symptoms before and after stent removal. Patients who would later undergo simple airway stent removal were prospectively recruited in two institutions. All stents were removed using both rigid and flexible bronchoscopes with patients under general anesthesia. Pulmonary function tests were performed before stent removal and at 1 and 4 weeks after stent removal. All patients self-reported their respiratory symptoms using a 100-mm visual analog scale (VAS). Of the 31 patients enrolled, 28 (23 with malignant stenoses, 3 with benign stenoses, and 2 with fistulas [21 silicone and 7 metallic stents]) were included in analyses. Pulmonary function measurements before stent removal and at 1 and 4 weeks after stent removal were as follows: vital capacity, 3.00, 3.04, and 3.08 L (p = 0.387); forced expiratory volume in 1 s, 1.96, 1.96, and 2.12 L (p = 0.034); and peak expiratory flow, 3.60, 4.28, and 5.06 L/s, respectively (p < 0.001). Symptoms (cough, sputum production, difficulty with expectoration, and dyspnea) evaluated using the VAS improved significantly after stent removal. No complications were encountered during removal. Removal of unnecessary airway stents improves pulmonary function and respiratory symptoms. Any stent that is no longer functioning should be removed.

Successful Biliary Navigation Using Air in Malignant and Post-Surgical Hilar Strictures: A Prospective Controlled Trial

Successful Biliary Navigation Using Air in Malignant and Post-Surgical Hilar Strictures: A Prospective Controlled Trial

Confocal laser endomicroscopy in gastro-intestinal endoscopy: technical aspects and clinical applications.

Confocal laser endomicroscopy (CLE) is an advanced endoscopic imaging technology that provides a magnified, cellular level view of gastrointestinal epithelia. In conjunction with topical or intravenous fluorescent dyes, CLE allows for an "optical biopsy" for real-time diagnosis. Two different CLE system have been used in clinical endoscopy, probe-based CLE (pCLE) and endoscope-based CLE (eCLE). Using pCLE, the device can be delivered: (I) into the luminal gastrointestinal tract through the working channel of standard endoscopes; (II) into extraluminal cystic and solid parenchymal lesions through an endoscopic ultrasound (EUS) needle; or (III) into the biliary system through an endoscopic retrograde cholangiopancreatography (ERCP) accessory channel. With eCLE, the probe is directly integrated into the tip of a conventional endoscope, however, these endoscopes are no longer commercially available. CLE has moderate to high diagnostic accuracy for neoplastic and inflammatory conditions through the gastrointestinal tract including: oesophageal, gastric and colonic neoplasia, pancreatic cysts and solid lesions, malignant pancreatobiliary strictures and inflammatory bowel disease. Some studies have demonstrated the diagnostic benefit of CLE imaging when combined with either conventional white light endoscopy or advanced imaging technologies. Therefore, optical biopsies using CLE can resolve diagnostic dilemmas in some cases where conventional imaging fails to achieve conclusive results. CLE could also reduce the requirement for extensive tissue sampling during surveillance procedures. In the future, CLE in combination with molecular probes, could allow for the molecular characterization of diseases and assess response to targeted therapy. However, the narrow field of view, high capital costs and specialized operator training requirements remain the main limitations. Future multi-center, randomized trials with a focus on conventional diagnostic applications, cost-effectiveness and standardized training will be required for definitive evidence. The objective of this review is to evaluate the technical aspects and current applications of CLE in patients with gastrointestinal and pancreatobiliary diseases and discuss future directions for this technique.

Contactless Measurement of Integrity of Silicone Coating on Self-Expandable Esophageal Nitinol Stents.

A stent is a mesh tube inserted into a natural passage in the body to prevent disease induction. Self-expandable esophageal nitinol stents such as SX-ELLA Stent Esophageal HV (HV Stent Plus) can be indicated for palliation of malignant esophageal strictures, for the treatment of benign esophageal strictures that are refractory to standard therapy and for the treatment of esophago-respiratory fistulas. A silicone-stent coating is used for tumor in-growth prevention and esophago-respiratory fistula occlusion. The thickness of the stent and the overall integrity of the silicone coating of all wires indicate the overall mechanical properties of the esophageal stent and the resistance to external adverse events such as corrosion and mechanical and chemical resistance. The polymer multicomponent epoxy resin - a mixture of Epon and Durcupan - was used as a method for robust sample stabilization. A cutting system using a thin water beam with a powder (Blue Line) was chosen as the best variant to obtain 6 samples for both-sided measurement (10 measuring sides). The optical microscopic reflective light method was used to examine wire crossing points in the sections. Fifty values were measured on either sample side for the internal, external and mesh thickness of the silicone stent layer. The wire crossing points were selected so that the silicone layer structure could be clearly seen, and the wires approached each other most closely. Only approximately 4 to 8 crossing points in each section could be measured when applying this approach. The resolution of the microscope and calibration (based on the camera used) was 0.677 μm/pixel. Additional data could be obtained on 8 planes. Two boundary samples were destroyed by the cutting process. Whole coating of the stent was around all mesh wires, especially in areas with higher mechanical stress (wire crossing). The minimum detectable and admissible value determined for all 3 measuring areas (internal, external, mesh) on the wire crossings was 6.77 μm, i.e., 10 pixels, based on the microscope resolution and manufacturer's methodology. The results were characterized by p < 0.001 for all 3 parameters. We tested opposite samples in each section to verify the section quality and data consistency. For the 4 areas, the data were significantly different, but the thickness differences were only on the order of units percent, so the measurements were not appreciably affected. We assume that the material cutting loss, making up 1-2 mm, contributed to the differences in the sections. We examined the overall integrity of the silicone coating of the esophageal stent. The method of HV stent anchoring in a polymeric bath followed by cutting with a waterjet and sample measurement under an optical microscope proved to be very simple and reliable. Sufficient thicknesses of the silicone layer on the wire cross sections were verified. The coated silicone layer thickness appeared to be significantly different along the stent from the proximal part to the distant part, presumably due to the manufacturing technology.

The outcomes of Endoscopic Ultrasound in the Management of Indeterminate Extra Hepatic Biliary Strictures: A Retrospective Study In a South African Tertiary Centre

Introduction: The diagnosis of indeterminate biliary stricture (IBS) remains a challenge. Endoscopic ultrasound (EUS) has been used to avoid unnecessary surgery. Methods: Prospectively collected EUS data at Chris Hani Baragwanath Academic Hospital was analysed. Patients with indeterminate biliary strictures on imaging and/or previous ERCP were included. Demographic, clinical, radiological, operative, and pathological data from April 2016 to August 2021 was analysed. Results: Thirty-three patients (23 males) presented with an IBS and underwent EUS. The median age was 55 years (25-76). Pre-EUS diagnoses included possible chronic pancreatitis (n=9), stone related stricture (n=6), periampullary/intraductal mass (n=3). In 15 cases no presumptive diagnosis was possible. EUS visual assessment suspected malignancy in 8 patients and benign disease in 25 patients. Six of 8 suspected malignant strictures were confirmed, 3 by EUS-FNA, 2 post-surgical resections, and one by cytology at ERCP. Sixteen of the 25 benign patients had confirmatory diagnoses of stone disease (n=8), benign stricture (n=4), and chronic pancreatitis (n=2). One suspected benign case had adenocarcinoma in the background of chronic pancreatitis. In 11 patients the follow-up data was incomplete. Overall, EUS had a sensitivity, specificity and accuracy of 85.71% (95%CI 42.13%-99.64%), 100.00% (76.84% to 100.00%) and 95.24% (95%CI 76.18%-99.88%) respectively. Conclusion: EUS is a useful adjunct as a diagnostic tool in patients with indeterminate biliary stricture. Further investigation is warranted to confirm these findings.