Push vs pull method for endoscopic ultrasound-guided fine needle aspiration of pancreatic head lesions: Propensity score matching analysis

AIM: To evaluate the efficacy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of pancreatic head cancer when pushing (push method) or pulling the echoendoscope (pull method). METHODS: Overall, 566 pancreatic cancer patients had their first EUS-FNA between February 2001 and December 2017. Among them, 201 who underwent EUS-FNA for pancreatic head lesions were included in this study. EUS-FNA was performed by the push method in 85 patients, the pull method in 101 patients and both the push and pull methods in 15 patients. After propensity score matching (age, sex, tumor diameter, and FNA needle), 85 patients each were stratified into the push and pull groups. Patient characteristics and EUS-FNA-related factors were compared between the two groups. RESULTS: Patient characteristics were not significantly different between the two groups. The distance to lesion was significantly longer in the push group than in the pull group (13.9 ± 4.9 mm vs 7.0 ± 4.9 mm, P < 0.01). The push method was a significant factor influencing the distance to lesion (≥ median 10 mm) (P < 0.01). Additionally, tumor diameter ≥ 25 mm (OR = 1.91, 95%CI: 1.02-3.58, P = 0.043) and the push method (OR = 1.91, 95%CI: 1.03-3.55, P = 0.04) were significant factors contributing to the histological diagnosis of malignancy. CONCLUSION: The pull method shortened the distance between the endoscope and the lesion and facilitated EUS-FNA of pancreatic head cancer. The push method contributed to the histological diagnosis of pancreatic head cancer using EUS-FNA specimens.