Can the wet suction technique change the efficacy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing autoimmune pancreatitis type 1? A prospective single-arm study

Figure 1 Target patients in this study and historical controls. The historical controls were 23 autoimmune pancreatitis patients who underwent endoscopic ultrasonography-guided fine-needle aspiration with no fewer than 4 punctures by 19 or 22 G needles. The target subjects in this study underwent endoscopic ultrasonography-guided fine-needle aspiration with a wet suction technique. The historical controls were considered the DRY group. AIP: Autoimmune pancreatitis; WEST: Wet suction technique.

Figure 2 The wet suction technique method of endoscopic ultrasonography-guided fine-needle aspiration. A: After the stylet of the needle was withdrawn, saline solution was injected into the needle; B: A locked suction syringe with 20 mL of negative pressure was set at the edge of the needle; C: The needle was used to puncture the target lesion; D: then, the lock on the syringe was opened. Saline solution flowed into the suction syringe due to the negative pressure.

Figure 3 The features of a patient with autoimmune pancreatitis diagnosed by endoscopic ultrasonography-guided fine-needle aspiration with a wet suction technique. A: The pancreatic tail is swollen with a capsule-like rim sign as observed on abdominal computed tomography; B: Specimen acquired by wet suction technique (WEST) endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) (HE × 200): IgG4-positive plasma cells were observed; C: Specimen acquired by WEST EUS-FNA (EM × 200): obliterative phlebitis was observed; D: Specimen acquired by WEST EUS-FNA (HE × 400): fibrosis with a storiform pattern of plasma cells was observed.