title: An Endovascular Cannulation Needle with an Internal Wire for the Fragmentation of Thrombi in Retinal Vein Occlusion.
abstract: OBJECTIVE
  We report a newly developed device to fragment thrombi in retinal vein occlusion.
  
  
  METHODS
  The new instrument consists of a 23-gauge (G) pipe and a 37-G needle with an internal wire. A total of 40 porcine eyes were used; 20 eyes for experiments in the branch retinal vein (BRV group) and 20 eyes for experiments in the central retinal vein (CRV group). We placed 25-G 3-port trocars, and core vitrectomy was performed. Another 23-G scleral incision was performed for insertion of the needle. The needle pierced the retinal vein at a distance of three- to four- or one-disc diameters from the optic disc (BRV or CRV group, respectively), and the internal wire was advanced toward the disc. The success rates of needle piercing and cannulation of the internal wire were recorded in each group. In the CRV group, the cannulation was deemed successful when the tip reached inside the optic disc. Real-time optical coherence tomography imaging also was performed using the Zeiss Rescan 700 device in porcine eyes. Histologic examination of the retinal vessel inserted with the internal wire was performed.
  
  
  RESULTS
  The success rates of needle piercing into the BRV and CRV were 85% and 95%, respectively. The success rates of cannulation of the internal wire into the BRV and CRV were 85% and 0%, respectively. The process of cannulation was recorded successfully with the Rescan 700. Histologic examination showed no damages to the endothelial cell layer.
  
  
  CONCLUSIONS
  The needle and internal wire intended to be used for recanalization of BRV occlusion were successfully pierced and cannulated into the BRV.
  
  
  CONCLUSIONS
  This newly developed device could become a treatment modality for retinal vein occlusion to fragment thrombi that present treatment methods cannot reach and remove directly.
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan ; Miyake Eye Hospital, Nagoya, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Asami
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Miyake Eye Hospital, Nagoya, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Miyake
authors.affiliation: Miyake Eye Hospital, Nagoya, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ota
authors.affiliation: Miyake Eye Hospital, Nagoya, Japan.
authors.forename: Goichiro
authors.initials: G
authors.lastname: Miyake
authors.affiliation: Department of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yasuda
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iwase
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Terasaki
keywords: branch retinal vein occlusion; clot fragmentation; endovascular cannulation; internal wire; recanalization; thrombus; vitrectomy