Background:

EUS-guided fine needle aspiration (FNA) is a major diagnostic tool in the patient with pancreatic mass with high specificity, specificity and accuracy. However FNA with small needle has sometimes failed in acquisition of tissue due to small caliber. To overcome this limitation, newly designed ProCore needle was developed and flexible 22 and 25 gauge ProCore needles were frequently used. However there was no comparative study of the efficacy and accuracy between 22 and 25 gauge ProCore needle yet.

Aim:

To compare the efficacy and accuracy of EUS-guided FNA between 22 and 25 gauge ProCore needle. (The investigators hypothesized that the accuracy of 25 gauge Procore needle is not inferior to 22 gauge ProCore needle.)

Patient and methods:

Patients who have pancreatic or peripancreatic mass in imaging studies which need pathologic confirm. These patients were randomly assigned to 22 gauge or 25 gauge group.

Procedure:

They underwent EUS-guided FNA, 3 times with 10 times of to-and pro movement each.

The number of patients required:

We used confidence intervals (CIs) with a prespecified non-inferiority margin of 10% for the non-inferiority analysis. We concluded non-inferiority of PC25 to PC22 if the lower limit of the 95% CI for the difference (PC25-PC22) was not lower than -10%. It was assumed that the diagnostic accuracy of one pass was 75% and that of three cumulative passes was estimated to be 98.4% in PC22. Based on these assumptions, the calculated sample size was 216 samples with power of 80% and significance level of 5%.

Inclusion Criteria:

• Patients who agree to participate in research
• 18 years of age and older patients
• Patients who have pancreatic or peripancreatic mass in imaging studies

Exclusion Criteria:

• Contraindication to endoscopy
• Patients younger than 18 years old
• Bleeding tendency
• Cardiopulmonary dysfunction