Development of a device for detecting target specimens from EUS-guided FNA samples

A Novel Monochromatic Light to Detect Target Specimens Within Endoscopic Ultrasonography-guided Fine-needle Aspiration Biopsy Samples

BACKGROUND/AIM

Endoscopic ultrasonography (EUS)-guided fine-needle aspiration biopsy (EUS-FNB) enhances the diagnostic capabilities of EUS by providing additional pathological samples. However, detecting the target specimens within the collected samples can be challenging. The aim of this study was to determine the optimal wavelength of light for detection of target specimens within EUS-FNB samples in an animal experiment.

MATERIALS AND METHODS

EUS-FNB pancreatic tissue samples were collected from a male beagle (weight, 10 kg), and the samples were illuminated with monochromatic light ranging from 430 to 700 nm in 5-nm intervals. The intensities of the target specimen and blood samples were analyzed using the densitometry of the images obtained through irradiation.

RESULTS

We found that transmitted monochromatic light of 605 nm most vividly enhanced the contrast between the target specimens and blood in the samples in the impression of appearance.

CONCLUSION

Thus, microscopical observations under transmitted light of 605 nm are optimal for target tissue identification within EUS-FNB samples.

Comparison between Target Sample Check Illuminator and White Light Observation in Discriminating the Presence of Target Specimen for Endoscopic Ultrasound-Guided Fine Needle Aspiration Sample

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an essential endoscopic tissue sampling method for diagnosing pancreatobiliary diseases; however, determining the presence of target specimens mixed in the blood by conventional observation is challenging due to the small size of the obtained sample. This study investigated the usefulness of a target sample check illuminator (TSCI) that emits a specific wavelength of light to determine the presence of target specimens. Twenty-seven patients who underwent EUS-FNA at our hospital were included. Conventional white light observation was performed for the collected samples, followed by TSCI; six people evaluated the presence of the target specimen on a 5-point scale. The target specimen discrimination score using TSCI (median: 5) was significantly higher than that using conventional white light observation (median: 1) (p < 0.001). No significant difference was observed in the discrimination score between the evaluator (novice vs. expert, p = 0.162) and puncture needle (22G vs. 25G, p = 0.196). The discriminability of TSCI in the samples obtained using EUS-FNA was significantly higher than that of conventional observation. TSCI does not depend on the evaluator or puncture needle for the identification of the target specimen; hence, it can provide a good pathological specimen and may contribute to the improvement of the diagnostic ability.

Usefulness of a target sample check illuminator in the detection of target specimens in endoscopic ultrasound-guided fine-needle biopsy samples: Multicenter prospective study

OBJECTIVES

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) uses a thin needle, rendering unclear whether the collected sample contains pathological evidence. We examined the usefulness of our target sample check illuminator (TSCI) through a multicenter prospective trial.

METHODS

We included 52 consecutive patients. After assessing EUS-FNB samples by conventional (visual observation) and TSCI methods, we evaluated consistency with the histopathological diagnosis. We compared the target sample confirmation rate between conventional and TSCI methods and evaluated the diagnostic ability separately.

RESULTS

Comparison between the conventional and TSCI methods revealed the following: (i) for all cases: sensitivity, 51.0% (25/49) vs. 95.9% (47/49) (P = 0.001); specificity, 100% (3/3) vs. 66.7% (2/3); positive predictive value (PPV), 100% (25/25) vs. 97.9% (47/48); and negative predictive value (NPV), 11.1% (3/27) vs. 50.0% (2/4) (P = 0.002); (ii) for pancreatic masses: sensitivity, 28.0% (7/25) vs. 96.0% (24/25) (P < 0.001); specificity, 100% (2/2) vs. 100% (2/2); PPV, 100% (7/7) vs. 100% (24/24); and NPV, 10.0% (2/20) vs. 66.7% (2/3) (P < 0.001) (the TSCI method showed significantly better sensitivity and NPV than the conventional method); and (iii) for lymph node tumors: sensitivity, 75.0% (18/24) vs. 95.8% (23/24) (P = 0.025); specificity, 100% (1/1) vs. 0% (0/1); PPV, 100% (18/18) vs. 95.8% (23/24); and NPV, 14.3% (1/7) vs. 0% (0/1).

CONCLUSIONS

The TSCI improved the sensitivity, NPV, and accuracy of target sample confirmation for pancreatic mass EUS-FNB. Although the proportion of samples not including a target region was quite low, which could strongly influence our results, the TSCI method can be used in EUS-FNB when rapid on-site evaluation cannot be performed. (A multicenter prospective study for the utility of a target sample check illuminator, Clinical Trial ID: UMIN000023349).

Endoscopic ultrasound-guided fine-needle aspiration biopsy - Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

A "Back Light System" for Identification of Sites for Endoscopic Ultrasound-Guided Fine-Needle Aspiration in Solid Pancreatic Masses: A Prospective, Randomized Study with a Crossover Design

Background/Aims

We applied a back light system (BLS) with a magnifying glass to improve the ability to assess the adequacy of specimen sampling using endosonography. We conducted this study to evaluate the efficacy of the BLS in sampling of specimens by endoscopic ultrasound-guided fine needle aspiration of solid pancreatic masses.

Methods

This was a prospective, randomized, crossover, single-center clinical trial. An endosonographer evaluated adequacy on gross visual inspection and identified whitish specimen sampling sites with and without the BLS according to a randomization sequence in the first and second passes with a 25-G needle. On cytological evaluation, the presence of well-defined pancreatic ductal epithelium was evaluated by a cytopathologist who was blinded to any clinical information.

Results

A total of 80 consecutive patients were eligible during the study period. Adequacy was observed for 52 specimens (65%) with the BLS and 54 (68%) without the BLS (p=0.88). In assessment of specimen adequacy on gross examination, only fair agreement was observed both with and without BLS (kappa score 0.40 and 0.29, respectively).

Conclusions

The BLS did not influence the ability to identify specimen sampling sites or reliable assessment of specimen site adequacy using gross visual inspection.

Efficacy and safety of pancreatic juice cytology by using synthetic secretin in the diagnosis of pancreatic ductal adenocarcinoma

BACKGROUND AND AIM

Pancreatic ductal adenocarcinoma (PDAC) is difficult to detect in its early stages with the poorest prognosis of all cancers. To improve the prognosis, a precise diagnosis is needed when we suspect PDAC. Although endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a widely accepted modality for the diagnosis of PDAC, its sensitivity is 85-89%, and approximately 10% of PDAC cases cannot be diagnosed. The main causes that interrupt the diagnosis of PDAC by using EUS-FNA are tumor size, presence of a vessel or the main pancreatic duct along the puncture route, and difficulty in withdrawing anticoagulant. Pancreatic juice cytology (PJC), the sensitivity of which is 33.3-65.8%, is a method for the diagnosis of PDAC cases in which carrying out of EUS-FNA is difficult. To diagnose PDAC appropriately, we need to improve the diagnostic ability of PJC.

METHODS

We examined PJC using synthetic secretin for 138 cases of pancreatic tumor and pancreatic non-cancerous diseases.

RESULTS

Sensitivity of PJC improved from 50.9% to 74.0% as a result of synthetic secretin loading, and 13 PDAC cases that had not been able to be diagnosed with EUS-FNA could be diagnosed pathologically by PJC. Although there were 12 patients with mild pancreatitis (8.7%) as a complication, all were relieved with conservative treatment.

CONCLUSION

Adding synthetic secretin to PJC is useful for cases in which it is difficult to carry out EUS-FNA for PDAC.

Pathological and Molecular Aspects to Improve Endoscopic Ultrasonography-Guided Fine-Needle Aspiration From Solid Pancreatic Lesions

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been applied to pancreatic lesions since the 1990s, and its use is now widespread. Improvements in endoscopic devices and sampling techniques have resulted in excellent diagnostic ability for solid pancreatic lesions. However, clinical improvements alone are not responsible for it; pathological aspects have also played important roles. Rapid on-site evaluation minimizes endoscopic procedures, although its value at improving the diagnostic ratio is still debated. Diagnostic efficacy differs by sample preparations (direct smear, cytospin, liquid-based cytology, cell block, and biopsy) and by staining methods (Papanicoloau, Diff-Quik, hematoxylin-eosin, and Giemsa). Several immunocytochemistry protocols aid in diagnosing epithelial components with cytological atypia and in differentiating various tumor types. One cytopathology diagnostic system is telecytology, which uses transmitted digital images and enables real-time diagnosis of EUS-FNA samples by expert cytologists at remote locations. However, EUS-FNA samples are useful for more than just diagnoses, as molecular analysis of these samples allows the identification of prognostic markers, such as genetic alterations in K-ras and EGFR. Expression of drug-metabolizing enzymes, human equilibrative nucleoside transporter 1, correlates with the response to gemcitabine-based chemotherapy. These pathology efforts have enhanced the diagnostic efficacy of EUS-FNA, thereby leading to better outcomes for patients with pancreatic diseases.

Role of the preoperative usefulness of the pathological diagnosis of pancreatic diseases

Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is currently capable of providing a cytopathological diagnosis of pancreatic malignancies with a higher diagnostic power, with a sensitivity and specificity of 85%-89% and 98%-99%, compared to pancreatic juice cytology (PJC), whose sensitivity and specificity are only 33.3%-93% and 83.3%-100%. However, EUS-FNA is not effective in the cases of carcinoma in situ and minimally invasive carcinoma because both are undetectable by endoscopic ultrasonography, although PJC is able to detect them. As for the frequency of complications such as post endoscopic retrograde cholangiopancreatography pancreatitis, EUS-FNA is safer than PJC. To diagnose pancreatic cancer appropriately, it is necessary for us to master both procedures so that we can select the best methods of sampling tissues while considering the patient’s safety and condition.

Efforts to improve the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration for pancreatic tumors

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used to obtain a definitive diagnosis of pancreatic tumors. Good results have been reported for its diagnostic accuracy, with high sensitivity and specificity of around 90%; however, technological developments and adaptations to improve it still further are currently underway. The endosonographic technique can be improved when several tips and tricks useful to overcome challenges of EUS-FNA are known. This review provides various techniques and equipment for improvement in the diagnostic accuracy in EUS-FNA.