A New Method for Endoscopic Sampling of Submucosal Tissue in the Gastrointestinal Tract: A Comparison of the Biopsy Forceps and a New Drill Instrument

Diagnostic yield of endoscopic and EUS-guided biopsy techniques in subepithelial lesions of the upper GI tract: a systematic review

BACKGROUND AND AIMS

Obtaining adequate tissue samples in subepithelial lesions (SELs) remains challenging. Several biopsy techniques are available, but a systematic review including all available techniques to obtain a histologic diagnosis of SEL is lacking. The aim of this study was to evaluate the diagnostic yield and adverse event rates of endoscopic biopsies, EUS-guided FNA (EUS-FNA), EUS-guided fine-needle biopsy (FNB) (EUS-FNB), and mucosal incision-assisted biopsy (MIAB) for SELs in the upper GI tract.

METHODS

A search strategy in multiple databases was performed. The primary outcome was diagnostic yield, defined as the percentage of procedures in which histology was obtained and resulted in a definitive histopathologic diagnosis. Secondary outcome measures included reported procedure-related adverse events, which were graded according to the AGREE (Adverse Events in Gastrointestinal Endoscopy) classification.

RESULTS

A total of 94 original articles were included. Studies were classified per endoscopic technique to obtain histopathology. This resulted in 8 included studies for endoscopic biopsy methods, 55 studies for EUS-FNA, 33 studies for EUS-FNB, and 26 studies for MIAB. Pooled rates for diagnostic yield were 40.6% (95% confidence interval [CI], 30.8-51.2) for endoscopic biopsy, 74.6% (95% CI, 69.9-78.7) for EUS-FNA, 84.2% (95% CI, 80.7-87.2) for EUS-FNB, and 88.2% (95% CI, 84.7-91.1) for MIAB. Reported procedure-related adverse events graded AGREE II or higher were 2.8% to 3.9% for endoscopic biopsies, 1.0% to 4.5% for EUS-FNA, .9% to 7.7% for EUS-FNB, and 1.9% to 7.9% for MIAB.

CONCLUSIONS

Based on the available evidence, MIAB and EUS-FNB seem to be most effective in terms of achieving a high diagnostic yield, with similar rates of adverse events.

Urodrill - a novel MRI-guided endoscopic biopsy technique to sample and molecularly classify muscle-invasive bladder cancer without fractionating the specimen during transurethral resection

The current diagnostic pathway for patients with muscle-invasive bladder cancer (MIBC), which involves with computed tomography urography, cystoscopy, and transurethral resection of the bladder (TURB) to histologically confirm MIBC, delays definitive treatment. The Vesical Imaging-Reporting and Data System (VI-RADS) has been suggested for MIBC identification using magnetic resonance imaging (MRI), but a recent randomized trial reported misclassification in one-third of patients. We investigated a new endoscopic biopsy device (Urodrill) for histological confirmation of MIBC and assessment of molecular subtype by gene expression in patients with VI-RADS 4 and 5 lesions on MRI. In ten patients, Urodrill biopsies were guided by MR images to the muscle-invasive portion of the tumor via a flexible cystoscope under general anesthesia. During the same session, conventional TURB was subsequently performed. A Urodrill sample was successfully obtained in nine of ten patients. MIBC was verified in six of nine patients, and seven of nine samples contained detrusor muscle. In seven of eight patients for whom a Urodrill biopsy sample was subjected to RNA sequencing, single-sample molecular classification according to the Lund taxonomy was feasible. No complications related to the biopsy device occurred. A randomized trial comparing this new diagnostic pathway for patients with VI-RADS 4 and 5 lesions and the current standard (TURB) is warranted.

Patient summary

We report on a novel biopsy device for patients with muscle-invasive bladder cancer that facilitates histology analysis and molecular characterization of tumor samples.

Trans-oral trans-sheath forceps biopsy for patients with severe esophageal obstruction under fluoroscopy

To investigate the safety and effectiveness of trans-oral trans-sheath forceps biopsy (TTFB) for patients with severe esophageal obstruction under fluoroscopy. From November 2016 to November 2019, 35 patients with level III or IV dysphagia and a Karnofsky score of less than 60 were enrolled to undergo TTFB and esophageal nutrition tube insertion or stenting simultaneously. Data on diagnostic performance, early complications, and radiation dose were collected, and Karnofsky scores before and after the procedures were compared. The technical success of TTFB was 100%. The sensitivity, specificity and accuracy were 92.3% (24/26), 77.8% (7/9), and 88.6% (31/35), respectively. Complications occurred in two cases (5.7%). The mean procedure duration and irradiation dose were 23.2 min and 7.2 mSv, respectively. The Karnofsky scores significantly increased after 2-4 weeks (t = 11.22, P < 0.0001). TTFB is a safe and effective method for patients with severe esophageal obstruction under fluoroscopy, especially in those who cannot undergo or refuse endoscopy.

Advancements in the Diagnosis of Gastric Subepithelial Tumors

A diagnosis of subepithelial tumors (SETs) is sometimes difficult due to the existence of overlying mucosa on the lesions, which hampers optical diagnosis by conventional endoscopy and tissue sampling with standard biopsy forceps. Imaging modalities, by using computed tomography and endoscopic ultrasonography (EUS) are mandatory to noninvasively collect the target's information and to opt candidates for further evaluation. Particularly, EUS is an indispensable diagnostic modality for assessing the lesions precisely and evaluating the possibility of malignancy. The diagnostic ability of EUS appears increased by the combined use of contrast-enhancement or elastography. Histology is the gold standard for obtaining the final diagnosis. Tissue sampling requires special techniques to break the mucosal barrier. Although EUS-guided fine-needle aspiration (EUS-FNA) is commonly applied, mucosal cutting biopsy and mucosal incision-assisted biopsy are comparable methods to definitively obtain tissues from the exposed surface of lesions and seem more useful than EUS-FNA for small SETs. Recent advancements in artificial intelligence (AI) have a potential to drastically change the diagnostic strategy for SETs. Development and establishment of noninvasive methods including AI-assisted diagnosis are expected to provide an alternative to invasive, histological diagnosis.