Comparison between modified wet suction and dry suction technique for endoscopic ultrasound-guided fine-needle biopsy in pancreatic solid lesions.

BACKGROUND AND AIM Although endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is widely applied, there is no clear consensus on the optimal biopsy technique. We describe a modified wet suction technique (MWEST) with the aim to compare the efficacy and safety between MWEST and the dry suction technique (DST). METHODS In this prospective, randomized, crossover, single-blinded study, patients with suspected pancreatic malignancy were randomized to the DST (group A) or MWEST (group B) for the first pass, and the two techniques were performed alternately. The primary outcome was the comparison of specimen adequacy and diagnostic yield between the techniques. Secondary outcomes included the macroscopic visible core (MVC) length, blood contamination of specimens, and adverse events of both techniques. RESULTS From January 2019 to September 2019, 216 passes were performed in 50 patients. The specimen adequacy was significantly higher in "per lesion" (P=0.026), "per pass" (cytology: P=0.034; histology: P=0.042), and first-pass analysis (P=0.034) for MWEST than for DST. In diagnostic yield, MWEST showed significantly superior histological yield (P=0.014) and first-pass analysis (kappa: MWEST: 0.743, DST: 0.519) compared to DST. MVC lengths were 8 mm (interquartile range [IQR]: 3.25-15 mm) and 10 mm (IQR: 5.25-15 mm) for DST and MWEST, respectively (P=0.036). Blood contamination was significantly more serious in DST than in MWEST (cytology: P=0.021; histology: P=0.042). CONCLUSIONS EUS-FNB with MWEST resulted in significantly better quality of specimen, histological, and first-pass diagnostic yields, and comparable safety compared to the DST. MWEST is preferred for EUS-FNB in pancreatic solid lesions.