Diagnostic performance of a new endoscopic scraper for malignant biliary strictures: a multicenter prospective study

A comparison of diagnostic utility of new endoscopic scraper combined cell block method and conventional brush catheter for biliary tract cancer

Background/Aims

The sensitivities of endoscopic trans-papillary pathologic diagnosis of biliary tract cancer (BTC) are unsatisfactory. Recently, the diagnostic utility of the endoscopic scraper device, Trefle for biliary stricture has been reported. The Trefle can be guided to the target biliary stricture over the guidewire and is as easy to use as the conventional brush catheter (CBC). This study evaluated the efficacy and safety of Trefle-assisted tissue acquisition combined cell block method and CBC cytology for biliary strictures due to BTCs.

Methods

We retrospectively reviewed consecutive patients with biliary strictures in whom CBC cytology or Trefle-assisted tissue acquisition under endoscopic retrograde cholangiopancreatography was performed for suspected BTCs from January 2015 to June 2022 at our institution.

Results

173 patients (CBC group; n = 55, Trefle group; n = 118) were enrolled in this study. The sensitivity, specificity, and accuracy of CBC cytology for BTC were 68.3%/100%/76.4%. On the other hand, the sensitivity, specificity, and accuracy of Trefle-assisted tissue acquisition for BTC were 93.7%/95.7%/94.1%, showing superior sensitivity (p < 0.001) and accuracy (p = 0.002) compared to that of CBC.

Conclusions

Compared to CBC cytology, Trefle-assisted tissue acquisition has superior diagnostic performance while maintaining procedural simplicity and is considered useful for diagnosing malignant biliary stricture.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: summary and recommendations

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for the diagnosis of malignancy in patients with biliary strictures of undetermined etiology. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses the role of fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS in the diagnosis of malignancy in patients with biliary strictures. In the endoscopic workup of these patients, we suggest the use of fluoroscopic-guided biopsy sampling in addition to brush cytology over brush cytology alone, especially for hilar strictures. We suggest the use of cholangioscopic and EUS-guided biopsy sampling especially for patients who undergo nondiagnostic sampling, cholangioscopic biopsy sampling for nondistal strictures and EUS-guided biopsy sampling distal strictures or those with suspected spread to surrounding lymph nodes and other structures.

American Society for Gastrointestinal Endoscopy guideline on role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: methodology and review of evidence

Biliary strictures of undetermined etiology pose a diagnostic challenge for endoscopists. Despite advances in technology, diagnosing malignancy in biliary strictures often requires multiple procedures. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the available literature on strategies used to diagnose undetermined biliary strictures. Using a systematic review and meta-analysis of each diagnostic modality, including fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS-guided FNA or fine-needle biopsy sampling, the American Society for Gastrointestinal Endoscopy Standards of Practice Committee provides this guideline on modalities used to diagnose biliary strictures of undetermined etiology. This document summarizes the methods used in the GRADE analysis to make recommendations, whereas the accompanying article subtitled "Summary and Recommendations" contains a concise summary of our findings and final recommendations.

Innovative method for the diagnosis of bile duct lesions using a novel tapered-tip sheath system to facilitate biliary biopsies

BACKGROUND AND AIMS

Pathologic evaluation of bile duct lesions is crucial for a definitive diagnosis and determination of an appropriate therapeutic strategy; however, current methods are limited by several challenges. This study evaluated the impact of a novel tapered-tip sheath system on biliary stricture diagnosis.

METHODS

This observational study evaluated 47 consecutive patients who underwent transpapillary biliary stricture biopsy using the novel tapered-tip sheath system from July 2020 to March 2022 compared with 51 historical control subjects undergoing conventional biopsies. Technical success rate, total biopsy time, number of biopsy specimens, adequate tissue sampling rate, adverse events, and diagnostic performance for biliary strictures were assessed.

RESULTS

The technical success rate was favorable in both groups, showing no significant difference (97.9% [46 of 47] vs 88.2% [45 of 51], P = .114). However, the total biopsy time was significantly shorter in the novel system group (3.7 vs 7.7 minutes, P < .001). The number of biopsy specimens did not differ between the groups; however, the novel system group had significantly more cases in which ≥3 tissue samples could be obtained (71.7% [33 of 46] vs 51.1% [23 of 45], P = .043), a higher adequate tissue sampling rate (88.2% vs 66.4%, P < .001), and fewer adverse events (6.4% vs 21.6%, P = .043). Although the diagnostic specificity of both groups was 100%, the novel system group had significantly higher diagnostic sensitivity and accuracy (82.1% vs 50% [P = .004] and 84.8% vs 55.5% [P = .005], respectively).

CONCLUSIONS

The novel tapered-tip sheath system is a promising tool for biliary stricture diagnosis.

Pathological and molecular diagnoses of early cancer with bile and pancreatic juice

The dismal prognosis of pancreaticobiliary malignancies is mainly attributed to the extremely difficult detection of early-stage lesions, including intraepithelial neoplasia. To improve prognosis, several studies on the early detection of cancer have been conducted using bile and pancreatic juices for pathological or molecular analyses. One approach is liquid biopsy that includes information about the tumor, such as circulating tumor cells, circulating tumor DNA, microRNAs, and exosomes released by the tumor. Another approach is proteomics/metabolomics that reflects specific conditions in the tumor. These two approaches lead to artificial intelligence-based multiomics analyses that comprises genomics, proteomics/metabolomics, and transcriptomics. Based on the findings of molecular analysis, pathological analysis using immunohistochemical staining/fluorescence in situ hybridization has also been developed. Moreover, there have been reports of new methods/ingenuities for obtaining appropriate samples for the diagnosis of early-stage cancer. Here we review the knowledge on cutting-edge pathological and molecular analyses of bile and pancreatic juices, introduce some ingenuities in sampling and sample processing to promote effective clinical practice, and provide a basis for future studies.

Use of Endoscopic Scraper and Cell Block Technique as a Replacement for Conventional Brush for Diagnosing Malignant Biliary Strictures

Histological evidence is essential for diagnosing malignant biliary strictures. However, conventional brush cytology remains the primary method used worldwide, despite its low diagnostic sensitivity and accuracy, as it is technically easy, rapid, and cost-effective. The aim of this study was to evaluate the diagnostic performance of a recently introduced endoscopic scraper, the simplicity of which is comparable to that of a conventional brush, by comparing diagnostic yields and the number of collected cells. The sensitivity of the endoscopic scraper when using the cell block technique was significantly higher than when using brush cytology or a brush with the cell block technique (53.6% vs. 30.9%, p < 0.001; 53.6% vs. 31.6%, p = 0.024, respectively). Quantitative digital image analysis of cell block sections revealed that the median number of cells obtained with the endoscopic scraper was significantly higher than when using the brush (1917 vs. 1014 cells, p = 0.042). Furthermore, seven cases (8.3%; 7/84) were diagnosed by immunohistochemical analysis of the cell block section obtained from the endoscopic scraper. Given its simplicity and greater capacity for sample acquisition, use of the endoscopic scraper in conjunction with the cell block technique could replace brush cytology for the histological diagnosis of malignant biliary strictures.

Evaluation of the Cell Block Method Using Overnight-Stored Bile for Malignant Biliary Stricture Diagnosis

The specimen collection and subsequent pathological diagnosis of malignant biliary stricture (MBS) are difficult. This study aimed to determine whether the cell block (CB) method using overnight-stored bile is useful in the diagnosis of MBS. This trial was a single-arm prospective study involving a total of 59 patients with suspected MBS. The primary endpoint was cancer detectability and accuracy using the CB method, and a comparison with the detectability and accuracy achieved with bile cytology was made. The immunohistochemical sensitivity for maspin and p53 was also investigated in the CB and surgical specimens. We were able to collect bile from all 59 patients, and 45 of these patients were clinically diagnosed with MBS. The cancer detectability using the CB method (62.2%) was significantly higher than that using cytology (37.8%) (p = 0.0344). When CB was combined with biopsy, the rates of cancer detectability (75.6%) and accuracy (81.4%) increased. In eight patients who received surgical therapy, maspin- and p53-immunohistochemistry was applied to the surgical and CB specimens, and cancer cells in both specimens showed positive cytoplasmic and nuclear staining for maspin and nuclear staining for p53. The CB method is, thus, useful for detecting malignancy (UMIN000034707).

More Endoscopy-Based Brushing Passes Improve the Detection of Malignant Biliary Strictures: A Multicenter Randomized Controlled Trial

INTRODUCTION

Endoscopic biliary brushing is the most common method used for sampling in patients with malignant biliary strictures (MBSs); however, its sensitivity is relatively low. There is still no consensus on endoscopy-based biliary brushing, although brushing 10 times in 1 specimen is routinely performed. This study was designed to compare the sensitivity of brush cytology for 10, 20, or 30 brushing times of a pass in 1 specimen in patients with MBSs.

METHODS

In this multicenter, prospective, randomized controlled study, patients who underwent endoscopic retrograde cholangiopancreatography for suspected MBSs were enrolled. Patients were randomly assigned to receive 10, 20, and 30 brushing times of a pass. The primary outcome was to compare the sensitivity of brush cytology among the 3 groups. Patients were prospectively followed up for 6 months after endoscopic brushing for malignancy diagnosis.

RESULTS

A total of 443 patients were enrolled for intention-to-treat analysis (147, 148, and 148 patients in the 10-times, 20-times, and 30-time groups, respectively). The 3 groups were similar in baseline characteristics. The sensitivity of brush cytology was 38%, 47%, and 57% in the 10-times, 20-times, and 30-times groups, respectively, and the 30-times group showed significantly higher sensitivity than the 10-times group (P = 0.001). The multivariate analysis revealed that stricture length and the number of brushing passes were significant factors for the detection of biliary malignancy. No significant differences were observed in procedure-related complications among the 3 groups.

DISCUSSION

Brushing 30 times could increase the diagnostic sensitivity without increasing complications and seems to be preferred for the endoscopic sampling and diagnosis of MBSs (chictr.org.cn, identifier: ChiCTR1800015978).

New technologies for indeterminate biliary strictures

An early and accurate diagnosis of biliary strictures yields optimal patient outcomes; however, endoscopic retrograde cholangiopancreatography (ERCP) with cytobrush/biopsy forceps has low sensitivity with a high number of false negatives. Various attempts to improve the accuracy of diagnosing indeterminate biliary strictures though ERCP-guided specimen acquisition have been proposed, such as with the use of fluorescence in situ hybridization, an endoscopic scraper, and the wire-grasping method, with modest to large improvements in sensitivity. Direct visualization of the biliary tree during peroral cholangioscopy has shown high sensitivity and specificity for the differentiation of neoplastic and non-neoplastic biliary lesions; however, there is no consensus on the visual characteristics of neoplastic lesions and moderate agreement between observers. Peroral cholangioscopy system (POCS)-guided specimen acquisition using forceps has shown inferior sensitivity compared to the visual characteristics; however, the specificity remains high. Optimal specimen processing with onsite evaluations and touch imprint cytology have been shown to improve the sensitivity and accurately diagnose nearly 90% of patients. In vivo evaluations of biliary strictures with probe-based confocal laser endomicroscopy have demonstrated high sensitivity with modest specificity for malignant biliary strictures. Optical computed tomography described reproductible criteria for malignancy detection in biliary strictures, increasing the sensitivity during ERCP evaluations. Differentiating benign causes from malignant causes of biliary strictures is a challenging task in clinical practice, with various concerns that still need to be addressed. Efforts should be made to define each diagnostic method's role in the evaluation of indeterminate biliary strictures.

Optimal tissue sampling during ERCP and emerging molecular techniques for the differentiation of benign and malignant biliary strictures

Patients with cholangiocarcinoma have poor survival since the majority of patients are diagnosed at a stage precluding surgical resection, due to locally irresectable tumors and/or metastases. Optimization of diagnostic strategies, with a principal role for tissue diagnosis, is essential to detect cancers at an earlier stage amenable to curative treatment. Current barriers for a tissue diagnosis include both insufficient tissue sampling and a difficult cyto- or histopathological assessment. During endoscopic retrograde cholangiopancreatography, optimal brush sampling includes obtaining more than one brush within an individual patient to increase its diagnostic value. Currently, no significant increase of the diagnostic accuracy for the new cytology brush devices aiming to enhance the cellularity of brushings versus standard biliary brush devices has been demonstrated. Peroral cholangioscopy with bile duct biopsies appears to be a valuable tool in the diagnostic work-up of indeterminate biliary strictures, and may overcome current technical difficulties of fluoroscopic-guided biopsies. Over the past years, molecular techniques to detect chromosomal instability, mutations and methylation profiling of tumors have revolutionized, and implementation of these techniques on biliary tissue during diagnostic work-up of biliary strictures may be awaited in the near future. Fluorescence in situ hybridization has already been implemented in routine diagnostic evaluation of biliary strictures in several centers. Next-generation sequencing is promising for standard diagnostic care in biliary strictures, and recent studies have shown adequate detection of prevalent genomic alterations in KRAS, TP53, CDKN2A, SMAD4, PIK3CA, and GNAS on biliary brush material. Detection of DNA methylation of tumor suppressor genes and microRNAs may evolve over the coming years to a valuable diagnostic tool for cholangiocarcinoma. This review summarizes optimal strategies for biliary tissue sampling during endoscopic retrograde cholangiopancreatography and focuses on the evolving molecular techniques on biliary tissue to improve the differentiation of benign and malignant biliary strictures.

Peroral Cholangioscopy-Guided Forceps Biopsy and Endoscopic Scraper for the Diagnosis of Indeterminate Extrahepatic Biliary Stricture

Background: Peroral cholangioscopy (POCS) has become a widely-used technique in diagnosing indeterminate biliary strictures, enabling optical viewing of the biliary system and targeted biopsies under direct vision. The diagnostic utility of the new endoscopic scraper, Trefle^®, for extrahepatic cholangiocarcinoma (ECC) has also been reported. However, the diagnostic utility of POCS-guided and Trefle^®-assisted tissue acquisition for ECC has never been compared empirically. We evaluated the efficacy and safety of Trefle^®-assisted tissue acquisition for diagnosing ECC compared with POCS-guided tissue sampling. Methods: Patients who underwent Trefle^®-assisted tissue acquisition or POCS-guided forceps biopsy to differentiate ECC from benign biliary disease between April 2014 and March 2018 were enrolled retrospectively. We evaluated the diagnostic performance of Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy based on pathological evaluation. We also compared adverse events associated with Trefle^®-assisted tissue acquisition with those of POCS-guided forceps biopsy. Results: We enrolled 34 patients with biliary disease and performed Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy in 14 and 20 patients, respectively. Sensitivity, specificity, and accuracy of Trefle^®-assisted tissue acquisition were 87.5%, 83.3%, and 85.7%, respectively, and for POCS-guided forceps biopsy, these were 90.0% each. Statistical values of Trefle^®-assisted tissue acquisition and POCS-guided tissue acquisition were not significantly different. There were no significant differences in the occurrence of adverse events between the Trefle^®-assisted tissue acquisition and the POCS-guided forceps biopsy (35.7% vs. 25.0%, p = 0.770). Compared with patients who underwent POCS procedure, endoscopic sphincterotomy was performed for fewer patients who underwent Trefle^®-assisted tissue acquisition (p < 0.001). Conclusions: The diagnostic ability of Trefle^®-assisted tissue acquisition for ECC is similar to that of POCS-guided tissue acquisition. Trefle^®-assisted tissue acquisition might also help to preserve the sphincter of Oddi and its digestive function.

Diagnostic Ability of Endoscopic Bile Cytology Using a Newly Designed Biliary Scraper for Biliary Strictures

BACKGROUND

A new device with metallic wires for scrape cytology was developed.

AIMS

To compare the diagnostic performance of scrape cytology and conventional cytology during endoscopic retrograde cholangiopancreatography for biliary strictures.

METHODS

A total of 420 cases with biliary stricture underwent transpapillary bile cytology. Among them, there are 79 cases with scrape cytology using the new device (scrape group) and 341 cases with conventional cytology (control group). Seventy-two and 174 cases underwent biliary biopsy at the same time as bile cytology in the scrape and control group, respectively.

RESULTS

The sensitivity for malignancy of bile cytology in the scrape and control group was 41.2% [pancreatic cancer (PC): 23.1%, biliary cancer (BC): 52.5%] and 27.1% (PC: 16.3%, BC: 38.0%), respectively (P = 0.023). When analyzed PC and BC, respectively, there was no significant difference between the two groups. In the both groups, the sensitivity was significantly higher for BC than PC. In the scrape group, there was no difference in the sensitivity between cytology and biopsy [39.7% (PC: 17.4%, BC: 55.3%)], but in the control group, a significantly lower sensitivity was observed with cytology than biopsy (36.4% (PC: 19.7%, BC: 50.0%)) (P = 0.046). When analyzed PC and BC, respectively, there was no significant difference between cytology and biopsy. The sensitivity of combined cytology and biopsy was 55.6% (PC: 30.4%, BC: 71.1%) in the scrape group and 47.0% (PC: 24.6%, BC: 64.3%) in the control group.

CONCLUSION

Scrape bile cytology for biliary strictures may be superior to conventional cytology.

Assessing the diagnostic yield of controllable biopsy-forceps for biliary strictures

OBJECTIVE

Biliary forceps biopsies are essential for differentially diagnosing biliary strictures and evaluating the preoperative superficial intraductal spread of bile duct cancers; however, these biopsies are technically demanding and time consuming. Using controllable biopsy-forceps (C-BF), which enable the tip's angle to be adjusted by up to 90°, may facilitate the procedure and improve the diagnostic yield for biliary biopsies. This study aimed to examine the efficacy of C-BF associated with the diagnosis of biliary strictures.

MATERIALS AND METHOD

Between 2009 and 2015, 110 patients with biliary strictures underwent biliary biopsies using C-BF. We retrospectively evaluated the diagnostic yield of C-BF for biliary strictures and determined the success rate associated with obtaining adequate samples during mapping biopsies to evaluate the superficial intraductal tumor spread.

RESULTS

The technical success rate for biliary biopsies using C-BF was 99% (109/110). The sensitivity, specificity and accuracy of the diagnoses of biliary strictures were 60% (46/77), 100% (33/33) and 72% (79/110), respectively. Regarding the mapping biopsy procedures, adequate samples were successfully obtained from 96% (22/23), 92% (11/12), 80% (12/15), 75% (9/12) and 31% (5/16) of the intrapancreatic common bile ducts, upper common bile ducts, confluences of the hepatic ducts, right intrahepatic bile ducts and left intrahepatic bile ducts, respectively.

CONCLUSIONS

C-BF may facilitate biliary cannulation and mapping biopsies of the common bile duct and the right intrahepatic bile duct. However, given that the diagnostic sensitivity was 60%, further modifications are expected and necessary to maximize the utility of the controllable mechanism.

Case of pancreatic metastasis from colon cancer in which cell block using the Trefle® endoscopic scraper enables differential diagnosis from pancreatic cancer

Endoscopic transpapillary brush cytology and forceps biopsy during endoscopic retrograde cholangiopancreatology are generally used to obtain pathological evidence of biliary strictures. Recently, the new endoscopic scraper Trefle^® has been reported and demonstrated high cancer detectability in malignant biliary strictures. This device is used to scrape the stricture over the guidewire, and, in the original method, the tissue and/or cell samples obtained are subjected to histological and/or cytological analysis separately. However, discrimination of chunks of tissue is hampered by the opacity of the surrounding fluid. We have developed a cell block technique for the Trefle^® device without dividing obtained specimens into tissue and cellular components, which is the simplest method and enables immunohistochemical analysis. We present a case of obstructive jaundice diagnosed immunohistochemically as pancreatic metastasis from colon cancer using cell block sections obtained with the Trefle^® device, which procedure is as easy as conventional brush cytology.