title: Evaluation of 19-gauge endoscopic ultrasonography aspiration needles using various echoendoscopes.
abstract: OBJECTIVE
  19-gauge (19G) needles are used for EUS-guided tissue acquisition and interventions. The aim of the current study was to compare the functional characteristics of 19G EUS needles by means of using various echoendoscopes in a bench simulator.
  
  
  METHODS
  The angles achieved for 19G needles (EchoTip: ET-19G, EchoTip Flex: ExF-19G, Expect: Ex-19G, and ProCore: PC-19G) and for the distal tip of the echoendoscope were evaluated for maximal angulation settings of the distal tip and the elevator. Also the resistance to advancement of the 19G needles at these endoscope settings was assessed. All evaluations were done with endoscopes in a straight and in a curved position.
  
  
  RESULTS
  There was no large discrepancy for scope and needle angles among all echoendoscopes except for the slim Pentax scope (EG-3270UK). The ExF-19G and PC-19G needles showed better optimal angles in various conditions compared to standard 19G needles. In straight scope position, out of the 20 conditions (5 endoscopes × 2 positions of the distal tip × 2 elevator positions) the numbers of optimal angulations achieved for the Ex-19G, ExF-19G, ET-19G, and PC-19G, were 11 /20 (55 %), 20 /20 (100 %), 14 /20 (70 %) and 18 /20 (90 %), respectively. However, regarding resistance, it was impossible to advance theneedle with 14 /20 settings (70 %) for the Ex-19G, 3 /20 (15 %) for the ExF-19G, 10 /20 (50 %) for the ET-19G and 7 /20 (35 %) for the PC-19G. When the scopes were bent, with regard to the force needed to advance the needle, the numbers of optimal settings, for the Ex-19G, ExF-19G, ET-19G, and PC-19G, were 1 (5 %), 13 (65 %), 6 (30 %) and 8 (40 %), respectively. The mean maximum resistance to advancement was less for the ExF-19G than for the other needless in almost all scope and angle conditions (p < 0.05).
  
  
  CONCLUSIONS
  Although there was no difference between needles, the resistance to passage was least with the flexible 19-gauge needle (ExF-19G).
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Itoi
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Fumihide
authors.initials: F
authors.lastname: Itokawa
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sofuni
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Kurihara
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tsuchiya
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Shujiro
authors.initials: S
authors.lastname: Tsuji
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Ikeuchi
authors.affiliation: Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawakami
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Moriyasu
authors.affiliation: First Department of Internal Medicine, Gifu University Hospital, Gifu.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yasuda