Vaporization of perfluorocarbon attenuates sea-water-drowning-induced acute lung injury by deactivating the NLRP3 inflammasomes in canines

Seawater-drowning-induced acute lung injury (SD-ALI) is a life-threatening disorder characterized by increased alveolar-capillary permeability, an excessive inflammatory response, and refractory hypoxemia. Perfluorocarbons (PFCs) are biocompatible compounds that are chemically and biologically inert and lack toxicity as oxygen carriers, which could reduce lung injury in vitro and in vivo. The aim of our study was to explore whether the vaporization of PFCs could reduce the severity of SD-ALI in canines and investigate the underlying mechanisms. Eighteen beagle dogs were randomly divided into three groups: the seawater drowning (SW), perfluorocarbon (PFC), and control groups. The dogs in the SW group were intratracheally administered seawater to establish the animal model. The dogs in the PFC group were treated with vaporized PFCs. Probe-based confocal laser endomicroscopy (pCLE) was performed at 3 h. The blood gas, volume air index (VAI), pathological changes, and wet-to-dry (W/D) lung tissue ratios were assessed. The expression of heme oxygenase-1 (HO-1), nuclear respiratory factor-1 (NRF1), and NOD-like receptor family pyrin domain containing-3 (NLRP3) inflammasomes was determined by means of quantitative real-time polymerase chain reaction (qRT-PCR) and immunological histological chemistry. The SW group showed higher lung injury scores and W/D ratios, and lower VAI compared to the control group, and treatment with PFCs could reverse the change of lung injury score, W/D ratio and VAI. PFCs deactivated NLRP3 inflammasomes and reduced the release of caspase-1, interleukin-1β (IL-1β), and interleukin-18 (IL-18) by enhancing the expression of HO-1 and NRF1. Our results suggest that the vaporization of PFCs could attenuate SD-ALI by deactivating NLRP3 inflammasomes via the HO-1/NRF1 pathway.

The cryobiopsy in interstitial lung diseases guided by probe-based confocal laser endomicroscopy is feasible

BACKGROUND

Transbronchial lung cryobiopsy (TBLB) is routinely used to diagnose the interstitial lung disease (ILD). These results are consistent with those of surgical lung biopsy. Fluoroscopy is also used to confirm the final position of the cryoprobe; however, it can increase radiation exposure for both patients and medical care personnel. Probe-based confocal laser endomicroscopy (pCLE) is a novel optical imaging technique that allows real-time imaging at the cellular level in vivo. pCLE technology can also be used to identify malignancy, acute rejection in lung transplantation, amiodarone lung, and pulmonary alveolar proteinosis and visualize elastin fibres in the alveolar compartment.

OBJECTIVES

The aim of this study is to investigate the ability of pCLE to distinguish fibrotic pulmonary issues from normal lung disease and the safety and feasibility of CLE-guided bronchoscopy and transbronchial lung cryobiopsy (TBLC) in patients with interstitial lung disease (ILD).

METHODS

pCLE images from 17 ILD patients were obtained during TBLB. These images were then compared with histology results to assess the correspondence rate.

RESULTS

pCLE imaging of the alveolar structures was performed. Key characteristics were visible, which could potentially influence the diagnostic rate (fibrotic areas) and the complication rate (blood vessel and pleura).

CONCLUSION

pCLE may reduce complications and increase the diagnostic yield. It is a potential guidance tool for cryobiopsy in the patients with ILD without fluoroscopy.

Probe-Based Confocal Laser Endomicroscopy versus White-Light Endoscopy with Narrow-Band Imaging for Predicting and Collecting Residual Cancer Tissue in Patients with Gastric Cancer Receiving Chemotherapy

Simple Summary

Collecting appropriate gastric cancer (GC) tissues is critical for molecular biology research or the development of new target drugs for cases resistant to chemotherapy. Chemotherapy may reduce or alter the distribution of GC tissue on the surface, making the detection of GC tissue during upper endoscopy challenging. Our study showed that probe-based confocal laser endomicroscopy (pCLE) is superior to white-light endoscopy (WLE) with magnifying narrow-band imaging (M-NBI) in terms of accuracy for diagnosing residual cancer in GC patients receiving chemotherapy. pCLE might be considered when it is necessary to confirm the presence of residual cancer and get tissue samples from GC patients receiving chemotherapy.

Abstract

In cases of progression despite chemotherapy, collecting gastric cancer (GC) tissues might be helpful for molecular biology research or the development of new target drugs for treating cases that are refractory to chemotherapy. Chemotherapy, however, may reduce or alter the distribution of GC tissue on the surface, making the detection of GC tissue during upper endoscopy challenging. Probe-based confocal laser endomicroscopy (pCLE) is a new technology that enables histological diagnosis by magnifying the mucous membrane to a microscopic level. Here, we evaluated whether pCLE could increase the yield of endoscopic biopsy for GC compared to white-light endoscopy (WLE) with magnifying narrow-band imaging (M-NBI) in GC patients receiving chemotherapy with its powerful imaging technique. Patients underwent WLE/M-NBI and pCLE for the detection of residual GC for the purpose of response evaluation or clinical trial registration. After WLE/M-NBI and pCLE, each residual GC lesion was biopsied for histological analysis. A total of 23 patients were enrolled between January 2018 and June 2020. Overall, pCLE showed significantly higher sensitivity and negative predictive value than WLE/M-NBI. The accuracy of pCLE was superior to that of WLE/M-NBI. Moreover, pCLE showed better predictive ability for residual GC than WLE/M-NBI, while WLE/M-NBI and pCLE showed inconsistent results. pCLE diagnosed residual GC more accurately than WLE/M-NBI, which resulted in an increased number of GC tissues collected during the endoscopic biopsy.

Bronchoscopic Probe-Based Confocal Laser Endomicroscopy to Diagnose Diffuse Parenchymal Lung Diseases

BACKGROUND

Diagnosis of diffuse parenchymal lung disease (DPLD) is based on clinical evaluation, radiological imaging and histology. However, additional techniques are warranted to improve diagnosis.

AIMS AND OBJECTIVE

Probe based confocal laser endomicroscopy (pCLE) allows real time in vivo visualisation of the alveolar compartment during bronchoscopy based on autofluorescence of elastic fibres. We used pCLE (Cellvizio®, Mauna Kea Technology. Inc, Paris, France) to characterise alveolar patterns in patients with different types of DPLD.

METHODS

In this pilot study we included 42 therapy naive patients (13 female, age 72.6 +/- 2.3 years), who underwent bronchoscopy for workup of DPLD. pCLE images were obtained during rigid bronchoscopy in affected lung segments according to HR-CT scan, followed by cryobiopsies in the identical area. Diagnoses were made by a multidisciplinary panel. The description of pCLE patterns was based on the degree of distortion of the hexagonal alveolar pattern, the density of alveolar structures, the presence of consolidations or loaded alveolar macrophages (AM). The assessment was performed by 2 investigators blinded for the final diagnosis.

RESULTS

The normal lung showed a typical alveolar loop pattern. In amiodarone lung disease loaded AM were predominant. COP showed characteristic focal consolidations. IPF was characterized by significant distortion and destruction, NSIP showed significant increase in density, and chronic HP presented with consolidations, mild distortion and density.

CONCLUSION

pCLE shows potential as an adjunctive bronchoscopic imaging technique in the differential diagnosis of DPLD. Structured and quantitative analysis of the images is required.

Probe-based confocal laser endomicroscopy for pleural malignancies diagnosis

Probe based confocal laser endomicroscopy (pCLE) is an optical imaging tool allowing live imaging of tissues at a cellular level. It remains experimental but its clinical value as a diagnostic/guiding tool is apparent. To address the lack of data in thoracic oncology and pleural diseases, we show the ability of pCLE during medical thoracoscopy to distinguish benign from malignant pleural involvement.

See relatedEditorial

Background and objective

Probe based confocal laser endomicroscopy (pCLE) is an optical imaging technique allowing live tissue imaging at a cellular level. Currently, this tool remains experimental. Two studies regarding pleural disease have been published and suggest that pCLE could be valuable for pleural disease investigations. However, normal and malignant pleural pCLE features remain unknown. Therefore, we conducted a prospective trial of pCLE during medical thoracoscopy to study and describe the malignant and benign pleural pCLE features.

Methods

Every patient >18 years referred to our department for medical thoracoscopy was eligible. Medical thoracoscopy was performed under sedation, allowing spontaneous breathing. Five millilitres of fluorescein (10%) was intravenously administrated 5 min before image acquisition. The pCLE was introduced through the working channel of the thoracoscope and gently placed on the parietal pleura to record videos. Afterwards, biopsies were performed on the corresponding sites. Malignant and benign pleural pCLE features were precisely described and compared using 11 preselected criteria.

Results

A total of 62 patients were included in the analysis including 36 benign and 26 malignant pleura. Among our preselected criteria, ‘abnormal tissue architecture’ and ‘dysplastic vessels’ were strongly associated with malignancies (100% and 85% ss, 721% and 74% sp, respectively) whereas, the ‘full chia seeds sign’ and ‘cell shape homogeneity’ were associated with benignity (36% and 56% ss, 100% and 70% sp, respectively). No study‐related adverse events occurred.

Conclusion

Benign and malignant pleural involvement have clearly distinct pCLE features.

Assessment of Endoscopic Healing by Using Advanced Technologies Reflects Histological Healing in Ulcerative Colitis

BACKGROUND

Several studies have reported that ulcerative colitis [UC] patients with endoscopic mucosal healing may still have histological inflammation. We investigated the relationship between mucosal healing defined by modified PICaSSO [Paddington International Virtual ChromoendoScopy ScOre], Mayo Endoscopic Score [MES] and probe-based confocal laser endomicroscopy [pCLE] with histological indices in UC.

METHODS

A prospective study enrolling 82 UC patients [male 66%] was conducted. High-definition colonoscopy was performed to evaluate the activity of the disease with MES assessed with High-Definition MES [HD-MES] and modified PICaSSO and targeted biopsies were taken; pCLE was then performed. Receiver operating characteristic [ROC] curves were plotted to determine the best thresholds for modified PICaSSO and pCLE scores that predicted histological healing according to the Robarts Histopathology Index [RHI] and ECAP 'Extension, Chronicity, Activity, Plus' histology score.

RESULTS

A modified PICaSSO of ≤ 4 predicted histological healing at RHI ≤ 3, with sensitivity, specificity, accuracy and area under the ROC curve [AUROC] of 89.8%, 95.7%, 91.5% and 95.9% respectively. The sensitivity, specificity, accuracy and AUROC of HD-MES to predict histological healing by RHI were 81.4%, 95.7%, 85.4% and 92.1%, respectively. A pCLE ≤ 10 predicted histological healing with sensitivity of 94.9%, specificity of 91.3%, accuracy of 93.9% and AUROC of 96.5%. An ECAP of ≤ 10 was predicted by modified PICaSSO ≤ 4 with accuracy of 91.5% and AUROC of 95.9%.

CONCLUSION

Histological healing by RHI and ECAP is accurately predicted by HD-MES and modified virtual electronic chromoendoscopy PICaSSO, endoscopic score; and the use of pCLE did not improve the accuracy any further.

Cresyl violet as a new contrast agent in probe-based confocal laser endomicroscopy for in vivo diagnosis of gastric intestinal metaplasia

BACKGROUND AND AIM

Cresyl violet (CV) is a topical dye that allows simultaneous chromoendoscopy and in vivo confocal laser endomicroscopy in identification of neoplastic changes of the lower gastrointestinal tract without intravenous injection of fluorescein, but as yet no investigation has reported its application in the diagnosis of gastric intestinal metaplasia (GIM). This study aims to assess the feasibility as well as diagnosis accuracy of topical CV for in vivo diagnosis of GIM by using probe-based confocal laser endomicroscopy (pCLE).

METHODS

In this prospective, open-label, feasibility study, 129 confocal videos from 22 patients with known GIM were analyzed and compared with corresponding histological images to establish the CV staining characteristics. In addition, 47 patients with known or suspected GIM were prospectively enrolled to evaluate the accuracy of this topical CV endomicroscopic imaging.

RESULTS

Probe-based confocal laser endomicroscopy with topical CV enabled clear visualization of the goblet cells, absorptive cells, and intestinal villi of GIM. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of pCLE diagnosis of GIM on a per-location analysis was 93.01%, 91.95%, 93.51%, 86.96%, and 96.11%, respectively. The intraclass correlation coefficient for inter-observer agreement and mean kappa value for intra-observer agreement for the diagnosis of GIM was 0.82 and 0.87, respectively.

CONCLUSIONS

Topical CV enables real-time chromoendoscopy in conjunction with pCLE examination of the stomach and warrants accurate diagnosis of GIM. It may be an acceptable and potentially alternative dye for confocal imaging in the future.

Diagnosis of Pancreatic Cystic Lesions by Virtual Slicing: Comparison of Diagnostic Potential of Needle-Based Confocal Laser Endomicroscopy versus Endoscopic Ultrasound-Guided Fine-Needle Aspiration

Background:

Pancreatic cystic lesions are often challenging entities for diagnosis and management. EUS-FNA diagnostic accuracy is limited by paucicellularity of cytology specimens and sampling errors. Needle-based confocal laser endomicroscopy (nCLE) provides real-time imaging of the microscopic structure of the cystic lesion and could result in a more accurate diagnosis.

Aims and Objectives:

To determine the diagnostic utility of in vivo nCLE and EUS-FNA in the diagnosis and histologic characterization of pancreatic cystic lesions (PCL).

Materials and Methods:

All patients diagnosed with PCL who had undergone nCLE and FNA over a 10-year period within a major urban teaching hospital were included in this study. All gastroenterology reports of the nCLE images and corresponding pathologist findings from the EUS-FNA were collected and compared with, a final diagnosis prospectively collected from clinicopathological and imaging data.

Results:

A total of n=32 patients were included in this study, which consisted of n=13 serous cystadenoma (SCA), n=7 intraductal papillary mucinous neoplasms (IPMN), n=2 mucinous cystic neoplasms (MCN), n=3 well-differentiated neuroendocrine tumors, n=2 cysts, n=2 benign pancreatic lesions, n=1 adenocarcinoma, n=1 gastrointestinal stromal tumor (GIST) and n=1 lymphangioma. The overall diagnostic rate was higher in nCLE (87.5%) vs. EUS-FNA (71.9%) While the diagnostic accuracy of nCLE and EUS-FNA were comparable in characterization of benign vs. malignant lesions, the nCLE diagnosis demonstrated higher accuracy rate in identifying mucinous cystic neoplasms compared to EUS-FNA.

Conclusion:

nCLE is a useful companion diagnostic tool for pancreatic cystic lesions and could assist the cytopathologist to better triage the sample for required ancillary testing and treatment planning. The combination of nCLE and EUS-FNA may be especially helpful in reducing the proportion of cases categorized as non-diagnostic.

In Vivo Endomicroscopy of Lung Injury and Repair in ARDS: Potential Added Value to Current Imaging

BACKGROUND

Standard clinical imaging of the acute respiratory distress syndrome (ARDS) lung lacks resolution and offers limited possibilities in the exploration of the structure-function relationship, and therefore cannot provide an early and clear discrimination of patients with unexpected diagnosis and unrepair profile. The current gold standard is open lung biopsy (OLB). However, despite being able to reveal precise information about the tissue collected, OLB cannot provide real-time information on treatment response and is accompanied with a complication risk rate up to 25%, making longitudinal monitoring a dangerous endeavor. Intravital probe-based confocal laser endomicroscopy (pCLE) is a developing and innovative high-resolution imaging technology. pCLE offers the possibility to leverage multiple and specific imaging probes to enable multiplex screening of several proteases and pathogenic microorganisms, simultaneously and longitudinally, in the lung. This bedside method will ultimately enable physicians to rapidly, noninvasively, and accurately diagnose degrading lung and/or fibrosis without the need of OLBs.

OBJECTIVES AND METHODS

To extend the information provided by standard imaging of the ARDS lung with a bedside, high-resolution, miniaturized pCLE through the detailed molecular imaging of a carefully selected region-of-interest (ROI). To validate and quantify real-time imaging to validate pCLE against OLB.

RESULTS

Developments in lung pCLE using fluorescent affinity- or activity-based probes at both preclinical and clinical (first-in-man) stages are ongoing-the results are promising, revealing correlations with OLBs in problematic ARDS.

CONCLUSION

It can be envisaged that safe, high-resolution, noninvasive pCLE with activatable fluorescence probes will provide a "virtual optical biopsy" and will provide decisive information in selected ARDS patients at the bedside.

Intraoperative Probe-Based Confocal Endomicroscopy to Histologically Differentiate Thyroid From Parathyroid Tissue Before Resection

BACKGROUND

Frozen section is the standard method to histologically distinguish parathyroid tissue from thyroid tissue during endocrine neck surgery. Frozen section can be time-consuming and costly. Its drawback is that it is to be performed only after the removal of a suspected pathological tissue. This study demonstrates the use of probe-based confocal laser endomicroscopy (pCLE) to confirm histology prior to tissue resection.

DESIGN

A prospective, single-institution, nonrandomized study was conducted. No sample size calculation was performed for this observational trial. The primary objective was the description of histological rendering of normal and pathological tissues through pCLE. Real-time in vivo fluorescence microscopy imaging was performed with the CystoFlex UHD probe after intravenous injection of 2.5 mL of 10% fluorescein sodium.

RESULTS

Eleven patients with hyperparathyroidism and thyroid conditions were included. A total of 104 videos showing thyroid, parathyroid, adipose tissue, muscle, laryngeal nerve, and lymph nodes were recorded. Videos were compared with visual information and pathological samples (when sampling was indicated). Thyroid tissue could be identified based on the presence of colloid follicles (intensely fluorescent area surrounded by a small ridge of low-fluorescence epithelial cells) including the pathognomonic aspect of resorption vacuole. Parathyroid tissue could be identified based on a regular, "diamond-shaped" capillary network encompassing parathyroid chief cells. Blinded reinterpretation of pCLE videos demonstrated an 89.3% sensitivity and a 90% specificity as compared with histology in tissue recognition.

CONCLUSION

This pilot study describes representative renderings of intraoperative pCLE to nontraumatically differentiate thyroid, parathyroid, and lymph nodes before surgical removal.

Multiscale Imaging of Brown Adipose Tissue in Living Mice/Rats with Fluorescent Polymer Dots

Brown adipose tissue (BAT) has been identified as a promising target for the treatment of obesity, diabetes, and relevant metabolism disorders because of the adaptive thermogenesis ability of this tissue. Visualizing BAT may provide an essential tool for pathology study, drug screening, and efficacy evaluation. Owing to limitations of current nuclear and magnetic resonance imaging approaches for BAT detection, fluorescence imaging has advantages in large-scale preclinical research on small animals. Here, fast BAT imaging in mice is conducted based on polymer dots as fluorescent probes. As early as 5 min after the intravenous injection of polymer dots, extensive fluorescence is detected in the interscapular BAT and axillar BAT. In addition, axillar and inguinal white adipose tissues (WAT) are recognized. The real-time in vivo behavior of polymer dots in rodents is monitored using the probe-based confocal laser endomicroscopy imaging, and the preferred accumulation in BAT over WAT is confirmed by histological assays. Moreover, the whole study is conducted without a low temperature or pharmaceutical stimulation. The imaging efficacy is verified at the cellular, histological, and whole-body levels, and the present results indicate that fluorescent polymer dots may be a promising tool for the visualization of BAT in living subjects.

In vivo diagnosis of early-stage gastric cancer found after Helicobacter pylori eradication using probe-based confocal laser endomicroscopy

BACKGROUND AND AIM

Early-stage gastric cancer (EGC) found after Helicobacter pylori (Hp) eradication often displays non-tumorous regenerative epithelium and/or maturated tumorous epithelium overlying the cancerous tissue, which may confuse endoscopic and histological diagnosis. Probe-based confocal laser endomicroscopy (pCLE) enables in vivo real-time optical biopsy. We compared the diagnostic yields for these EGC cases using conventional white light endoscopy (WL), magnifying endoscopy with narrow-band imaging (ME-NBI), pCLE, and endoscopic biopsy; we also compared the accuracy of the horizontal extent diagnosis between ME-NBI and pCLE.

METHODS

This study enrolled 30 patients with 36 EGC lesions after successful Hp eradication. Diagnostic yields of WL, ME-NBI, pCLE, and endoscopic biopsy were prospectively compared. Four points of cancerous margins (oral, anal, anterior, and posterior sites) were also prospectively evaluated with M-NBI and pCLE to determine the horizontal extent of the EGC.

RESULTS

Diagnostic yield was significantly higher with pCLE than with WL and endoscopic biopsy (97 vs 72%, 97 vs 72%, P = 0.0159, 0.0077, respectively), whereas it did not differ from ME-NBI (88.9%, P = 0.371). Height of non-tumorous regenerative epithelium or maturated atypical glands was 104.7 ± 34.2 μm in the pCLE-positive cases, whereas it was 188.3 ± 27.1 μm in a pCLE-negative case (P = 0.0004). Diagnostic accuracy of the horizontal margin of EGC was significantly higher with pCLE than with ME-NBI (92 vs 70%, P = 0.0159).

CONCLUSION

pCLE may be helpful for the diagnosis of ambiguous ECG found after Hp eradication because it enables real-time scanning throughout the lesion and detection of subsurface microstructure.

Probe-based confocal laser endomicroscopy in the margin delineation of early gastric cancer for endoscopic submucosal dissection

BACKGROUND AND AIM

We evaluated probe-based confocal laser endomicroscopy (pCLE) in the margin delineation of early gastric cancer (EGC) for endoscopic submucosal dissection in comparison with white-light imaging with chromoendoscopy (CE).

METHODS

We conducted a prospective, randomized controlled study from November 2013 to October 2014 in a tertiary referral hospital. A total of 101 patients scheduled for endoscopic submucosal dissection due to differentiated EGC were randomized into pCLE and CE groups (pCLE 51, CE 50). Markings were made by electrocautery at the proximal and distal tumor margins, as determined by either pCLE or CE. The distance from the marking to the tumor margin was measured in the resected specimen histopathologically and was compared between the two groups by a linear mixed model.

RESULTS

Among 104 lesions, 80 lesions with 149 markings (pCLE 68, CE 81) were analyzed after excluding undifferentiated EGCs (n = 8) and unidentifiable markings (n = 13). Although the complete resection rate showed no difference between the groups (94.6% vs 93.2%, P = 1.000), the median distance from the marking to the margin was shorter in the pCLE group (1.3 vs 1.8 mm, P = 0.525) and the proportion of the distance <1 mm was higher (43.9% vs 27.6%, P = 0.023) in the pCLE group. Finally, subgroup analysis with superficial flat lesions (18 lesions, 31 marking dots) showed a significantly decreased distance in the pCLE group (0.5 vs 3.1 mm, P = 0.007).

CONCLUSIONS

Among EGCs with superficial flat morphology, in which the accurate evaluation of lateral extent is difficult with CE, pCLE would be useful for more precise margin delineation.

Development of a new classification for in vivo diagnosis of duodenal epithelial tumors with confocal laser endomicroscopy: A pilot study

BACKGROUND AND AIM

Confocal laser endomicroscopy (CLE) has been established for in vivo diagnosis of various gastrointestinal diseases. However, validated criteria for confocal diagnosis of duodenal tumors do not exist. Therefore, the aim of the present pilot study was to develop a novel classification for in vivo optical diagnosis of duodenal tumors using CLE.

METHODS

Consecutive patients with duodenal tumorous lesions were included. First, an initial classification system was developed which was then validated. Histopathology was used as a reference standard.

RESULTS

A simple classification system for in vivo diagnosis of duodenal epithelial tumors using CLE was developed. Sensitivity, specificity, and accuracy were 90%, 100%, and 97%, respectively. Positive and negative predictive values were calculated as 100% and 96%. The kappa coefficient representing consistency was 1 between observers and within each observer.

CONCLUSION

A new classification for in vivo diagnosis of duodenal epithelial tumors using confocal imaging has been developed. The new classification system allows adequate prediction of histology and could therefore be used to guide subsequent therapy of duodenal lesions.

Outcome of probe-based confocal laser endomicroscopy (pCLE) during endoscopic retrograde cholangiopancreatography: A single-center prospective study in 45 patients

BACKGROUND

Diagnosis of pre-malignant and malignant lesions in the bile duct and the pancreas is sometimes cumbersome. This applies in particular to intraductal papillary mucinous neoplasia (IPMN) and bile duct strictures in primary sclerosing cholangitis (PSC).

AIMS

To evaluate in a prospective cohort study the sensitivity and specificity of probe-based confocal laser microscopy (pCLE) during endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

We performed pCLE together with mother-baby endoscopy (SpyGlass) during 50 ERCP sessions in 45 patients. The Miami and Paris criteria were applied. Clinical diagnosis via imaging was compared to pCLE and the final pathological diagnosis from surgically-resected, biopsy, or cytology specimens. Patients were followed up for at least 1 year.

RESULTS

We were able to perform pCLE in all patients. Prior to endoscopy, the diagnosis was benign in 23 patients and undetermined (suspicious) in 16 patients, while six patients had an unequivocal diagnosis of malignancy. Sensitivity was 91% and specificity 52%. The positive (PPV) and negative predictive value (NPV) was 82% and 100%, respectively. Apart from mild post-ERCP pancreatitis in two patients, no complications occurred.

CONCLUSIONS

Our study showed that pCLE is a safe, expert endoscopic method with high technical feasibility, high sensitivity and high NPV. It provided diagnostic information that can be helpful for decisions on patient management, especially in the case of IPMN and unclear pancreatic lesions, in individuals whom are at increased risk for pancreatic cancer.

Comparison between two types of confocal laser endomicroscopy in gastrointestinal tract

OBJECTIVES

Confocal laser endomicroscopy (CLE) consists of endoscope-based CLE (eCLE) and probe-based CLE (pCLE). This study aimed to compare eCLE and pCLE in their diagnostic yield in different parts of the gastrointestinal (GI) tract.

METHODS

Consecutive patients were scheduled for CLE examination due to GI symptoms. All patients were randomly assigned to eCLE or pCLE group and underwent a programmed procedure using one type of CLE. Differences in procedure time, complication rate, CLE image quality and image acquisition feasibility between these two types of CLE for esophagogastroduodenoscopy (EGD) and colonoscopy were calculated.

RESULTS

Altogether 513 CLE procedures were performed, including 324 EGD and 189 colonoscopy. The procedure time of pCLE was significantly shorter than that of eCLE both in EGD and colonoscopy (16.78 min vs 18.13 min for EGD, P = 0.027; 32.48 min vs 39.89 min for colonoscopy, P < 0.001). No significant difference was found between these two types of CLE in diagnostic utility, including the detection and prediction of histopathological results of the lesions. The CLE image quality of both eCLE and pCLE were comparable in the stomach and colon, but eCLE seemed to be superior to pCLE in examining the esophagus. Colonoscopy using pCLE had a higher complete rate than that of eCLE, although the difference was not statistically significant (P = 0.065).

CONCLUSIONS

pCLE is more flexible in diagnosing GI diseases with a shorter procedure time than eCLE regardless of comparable diagnostic yields, except the diagnosis of esophageal diseases in which eCLE provides better image quality.

Early detection of acute graft-versus-host disease by wireless capsule endoscopy and probe-based confocal laser endomicroscopy: results of a pilot study

OBJECTIVE

Acute gastrointestinal graft-versus-host disease (GI-GVHD) is usually diagnosed using endoscopic examinations and biopsies for conventional histology. The aim of this pilot study was to determine whether mini-invasive techniques such as probe-based confocal laser endomicroscopy (pCLE) combined with wireless capsule endoscopy (WCE) could detect early lesions of GI-GVHD prior to symptoms.

DESIGN

Fifteen patients undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT) were prospectively examined with a small bowel WCE, duodenal and colorectal pCLE, and standard biopsies. Per study protocol, all these examinations were scheduled between day 21 and day 28 after allo-HSCT, independently of the presence or absence of digestive symptoms.

RESULTS

During follow up, eight patients developed acute GI-GVHD. Sensitivity of WCE, pCLE, and histology were 50, 87.5, and 50%, respectively. Specificity of WCE, pCLE, and histology were 80, 71.5, and 80%, respectively. We showed a positive correlation between the Glücksberg scoring system and WCE (rho = 0.543, p = 0.036) and pCLE (rho = 0.727, p = 0.002) but not with standard histology (rho = 0.481, p = 0.069).

CONCLUSIONS

The results from this pilot study suggest that novel methods such as pCLE and WCE could be part of a mini-invasive algorithm for early detection of GI-GVHD.

Endomicroscopy in bile duct: Inflammation interferes with pCLE applied in the bile duct: A prospective study of 54 patients

BACKGROUND

The preoperative diagnosis of biliary stenosis is associated with low accuracy. As a consequence, probe-based confocal laser endomicroscopy (pCLE), an in-vivo histological imaging technique, was applied in the bile duct. The aim of this study was to establish whether previous inflammation of the bile duct affects confocal interpretation. The findings from pCLE were compared in two groups of patients: those in whom there had been no cholangitis nor stenting and those in whom stents had been used and subsequently retrieved or who had suffered cholangitis.

PATIENTS AND METHODS

pCLE was performed on 54 patients (mean age 66 years; 31 men, 23 women) from September 2008 to July 2011. Patients were divided in two groups: group 1: 39 patients who had not undergone a biliary procedure in the month preceding the pCLE procedure; and group 2: 15 patients who had undergone stent placement or presented with cholangitis in the month preceding the pCLE procedure. Endoscopic and pCLE data were collected prospectively. pCLE results were compared to benchmark histology (surgery, endoultrasonography, percutaneous biopsy). Patients with a benign stricture who did not undergo operation were followed for 1 year. pCLE images of the bile duct were obtained during endoscopic retrograde cholangiopancreatography procedures. pCLE images were interpreted prospectively using the Miami classification in vivo and in real time.

RESULTS

In group 1, sensitivity, specificity, and accuracy were 88, 83, and 87%, respectively. In group 2, sensitivity, specificity, and accuracy were 75, 71, and 73%, respectively. Diagnostic accuracy of pCLE was lower when applied to group 2 (p < 0,001). The investigation is less reliable in bile ducts affected by inflammation from cholangitis or previous stenting.

CONCLUSIONS

Inflammatory lesions of the bile duct interfere with interpretation of pCLE. A refined pCLE description of inflammatory lesions should improve accuracy of pCLE in bile duct stenosis.