Related Experiment Video
Updated: Apr 15, 2026

Author Spotlight: Advancing Biopsy Techniques with Transesophageal Ultrasound
Published on: November 21, 2023
Forward-viewing versus oblique-viewing echoendoscopes in the diagnosis of upper GI subepithelial lesions with
Ippei Matsuzaki1, Ryoji Miyahara1, Yoshiki Hirooka2
1Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Background:
The role of the forward-viewing echoendoscope compared with the oblique-viewing echoendoscope for EUS-guided FNA (EUS-FNA) of upper GI subepithelial lesions has not been defined.
Objective:
To compare the diagnostic yield and clinical efficacy of EUS-FNA by using the 2 echoendoscopes in the same upper GI subepithelial lesion.
Design:
Prospective, randomized, crossover study.
Setting:
Tertiary-care medical center.
Patients:
Forty-one patients with an upper GI subepithelial lesion.
Interventions:
All patients first underwent EUS-FNA with a 19-gauge needle by using both echoendoscopes, based on random selection. When required, 22-gauge or 25-gauge needles were used additionally.
Main Outcome Measurements:
Comparison of diagnostic yield, tissue sample area, puncture success rates, procedure time, and adverse events.
Results:
Forty-one patients (median lesion size 22 mm, range 15-63 mm) were enrolled. Rates of histologic diagnosis were 80.5% (33/41) and 73.2% (30/41) (P=.453) by using forward-viewing and oblique-viewing echoendoscopes, respectively. Median tissue sample area in GI stromal tumors (n=22) obtained with the forward-viewing echoendoscope was larger than with the oblique-viewing echoendoscope (2.46 mm2 vs 1.00 mm2; P=.046). Puncture success rates were 39 of 41 (95.1%) and 35 of 41 (85.4%; P=.289) with forward-viewing and oblique-viewing echoendoscopes, respectively. Median procedure time was 21 minutes with the forward-viewing echoendoscope and 27 minutes with the oblique-viewing echoendoscope (P=.009). An infectious adverse event occurred in a patient and was treated with antibiotics.
Limitations:
Small sample size.
Conclusion:
Diagnostic yield did not differ between the 2 echoendoscopes. However, tissue sample area and procedure time were superior with the forward-viewing echoendoscope.
Related Concept Videos
Ultrasound II: Endoscopic Ultrasound and FibroScan
Endoscopic Ultrasound (EUS):
Endoscopic Procedures I: Esophagogastroduodenoscopy
During an EGD, the endoscope can be used to:
Ultrasonography
During an ultrasonography procedure, a handheld device called...
Endoscopic Procedures III: Video Capsule Endoscopy
Endoscopic Studies I: Bronchoscopy and Thoracoscopy
Bronchoscopy
Description
Bronchoscopy is a procedure that involves direct visualization of the larynx, trachea, and bronchi for diagnostic and therapeutic purposes. A flexible fiber optic or rigid bronchoscope is used to carry out the procedure. The fiber-optic bronchoscope is more frequently used due...
Urologic Endoscopic Procedure: Cystoscopic Examination
