Efficacy of Endoscopic Ultrasound-guided Fine Needle Biopsy With Simplified Macroscopic On-site Evaluation (With Video).

With advances in preoperative chemotherapy and comprehensive genomic profiling, endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) has become vital for diagnosing pancreatic and peridigestive tract lesions. However, evidence remains limited regarding the performance of new-generation puncture needles and simplified specimen evaluation methods. This study retrospectively assessed the diagnostic ability and procedural adverse events (AEs) of a new-generation puncture needle for solid pancreatic, subepithelial, and other lesions. We analyzed data from 1232 consecutive patients who underwent EUS-FNB between August 2016 and November 2023 at a single care center. Specimen processing was performed using the simplified macroscopic on-site evaluation (S-MOSE) method, which does not require additional pathological tests such as rapid on-site evaluation or cytology. The overall diagnostic accuracy using S-MOSE was 93.7%. Specifically, the diagnostic accuracy for pancreatic cancer was 95.8%. The AE rate was 1.1% (14/1232), including pancreatitis (six), hemorrhage (five), hematoma (two), and pancreatic fistulas (one). The first puncture diagnostic rate was 83.6%, which increased to 92.5% after the second puncture, with only a marginal gain of 1.2% beyond the third puncture. Multivariable analysis identified smaller lesion size and benign pathology as factors associated with lower diagnostic accuracy; conversely, malignant pathology was associated with higher diagnostic accuracy (odds ratio 1.895, p = 0.011). EUS-FNB with S-MOSE, typically requiring up to two punctures, provides efficient and accurate histopathological diagnosis across diverse lesions while minimizing procedural burden. Trial Registration: N/A.