Introduction
Endoscopic ultrasound (EUS) has broadened its diagnostic and therapeutic scopes, as it is able to target lesions <3mm. High-frequency radial EUS-miniprobes exhibit procedural time reduction, improving image quality and maneuverability. EndoSound Vision System (EndoSound, Oregon, USA) is a new EUS (N-EUS) portable device that fastens onto a standard gastroscope, enabling a free working channel. It is an affordable alternative to conventional-EUS devices; and a promising opportunity to shorten the difficult EUS learning curve.
Aims & Methods
We aim to determine the feasibility and effectiveness of N-EUS in terms of anatomical structures appropriate identification in comparison with conventional-EUS. This prospective study included patients ≥18 years-old undergoing EUS evaluation in June-November 2023 by eight endoscopists from different institutions from South and North America. Patients underwent two consecutive procedures: First, a conventional EUS with a linear-array echoendoscope (Pentax EG38-J1OUT, Pentax Medical, Germany). Then, a different endoscopist performed EUS using the N-EUS coupled to a video gastroscope with therapeutic access (EG29-i10, Pentax Medical, USA). A post-procedure ad-hoc survey was completed by the second endoscopist, to assess N-EUS acceptability in terms of endoscopists’ experience using this device.
Results
Thirty-one patients underwent conventional EUS and N-EUS: 16/31 performed by first-time N-EUS users, 15/31 by endoscopists with prior N-EUS exposure, with median procedural times of 30 and 15 minutes, respectively (p=.04). Main EUS indication was chronic dyspepsia (35.5%). Identified structures during N-EUS were the liver/gallbladder/common bile duct (30/31, 96.8%), full pancreas (29/31, 93.5%), kidneys/left kidney (24/31, 77%; 13/15 endoscopists with prior exposure vs 11/16 first-time N-EUS users; p<.001), left adrenal gland (20/31, 64.5%). Gallbladder (GB) was unobserved in 8 cases, 7/8 had prior cholecystectomy. Evaluation position was 54.8% supine; 3/31 switched to left lateral. All procedures were completed with 100% clinical and technical success, requiring navigation changes in 51.6%, mainly in first-time N-EUS users (p=.001). FNB tissue sampling was achieved in 100% cases. Endoscopists’ experience was predominantly described as “meeting clinical expectations”. The ad-hoc survey showed high psychometrics, with homogeneity among surveyed endoscopists, without redundancy (Cronbach’s alpha of .91), and a good construct validity (Kaiser-Meyer-Olkin Criterion of .728 and Barlett´s test p-value =.0005). When comparing both procedures, appropriate identification of GB or lack of, full pancreas, left/both kidneys and left adrenal gland was 31/31 vs 30/31, 31/31 vs 29/31, 31/31 vs 24/31 (p=.0233), and 29/31 vs 20/31 (p=.0158), respectively. Considering conventional EUS as a gold standard, the observed agreement of N-EUS to identify these structures were 96.8%, 93.5%, 77.4% and 64.5%, correspondingly. Observed agreement for kidneys and left adrenal gland increased when sub-analyzing the cases assessed by endoscopists with prior N-EUS exposure: 81.2% and 76.9%, respectively.
Conclusion
N-EUS is a safe, effective, and feasible tool for EUS evaluation, with high acceptability by endoscopists. Prior ex-vivo training may be warranted for first-time N-EUS users.
References
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Disclosure
Carlos Robles-Medranda is a key opinion leader and consultant for Pentax Medical, Boston Scientific, Steris, Medtronic, Motus, Micro-tech, G-Tech Medical Supply, CREO Medical, EndoSound, and mdconsgroup. All other authors declare no conflicts of interest.