title: In Vivo Retinal Vein Bypass Surgery in a Porcine Model.
abstract: OBJECTIVE
  To evaluate the feasibility of retinal vein bypass surgery for induced branch retinal-vein occlusion (BRVO) in the living porcine eye.
  
  
  METHODS
  Fifteen minipigs were used in the study. Seven days before vascular surgery, hyaluronidase and plasmin were intravitreally injected for induction of posterior vitreous detachment. Aspirin and warfarin were oral administered daily starting 5 d prior to vascular surgery for anti-coagulation. The minipigs were anethetized with an intraperitoneal injection of 300 mg/kg chloral hydrate for intravitreal injection procedure and vascular surgery. Temporary keratoprosthesis vitrectomy was performed, and intraoperative video fluorescein angiography (VFA) was possible. The central and posterior vitreous was removed together with the posterior hyaloid membrane to facilitate vascular maneuvers. BRVO was induced by bipolar diathermy on the vein at the main vein's first branching. Polyimide tubes (50.8-μm internal diameter and 7.6-μm wall thickness) were used as artificial vessels. Vascular manipulation was performed in a bimanual manner. Both end of a prepared tubing was inserted into venous lumen by puncturing and catheterization, and the vein bypass bridging the occlusion was created. Then, the patency of the bypass graft was assessed by intraoperative VFA.
  
  
  RESULTS
  The retinal vein bypass surgery was surgically accomplished in 33% (5/15) of the eyes, and the immediate graft patency was confirmed by intraoperative VFA only in one eye. We observed and recorded fluorescein flow from the branch vein to the main vein through the bypass graft which bridging the occlusive vein segment.
  
  
  CONCLUSIONS
  We demonstrated the feasibility of retinal vein bypass for induced BRVO in the living porcine eye, and the immediate graft patency was successfully evaluated by intraoperative VFA. Despite the potential, there are still some significant hurdles in vivo retinal vein bypass surgery, and modification of both surgical instruments and maneuvers is needed for further study.
authors.affiliation: a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi An , Shan Xi , China and.|b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Shen
authors.affiliation: b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Yi-Qi
authors.initials: YQ
authors.lastname: Chen
authors.affiliation: b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Dan
authors.initials: D
authors.lastname: Cheng
authors.affiliation: b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Chaote
authors.initials: C
authors.lastname: Zhang
authors.affiliation: b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Lu
authors.initials: L
authors.lastname: Jiang
authors.affiliation: b The School of Optomery & Opthalmology, Eye Hospital, Wenzhou Medical University , Wen Zhou , Zhe Jiang , China.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Hong
authors.affiliation: a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi An , Shan Xi , China and.
authors.forename: Qian-Yan
authors.initials: QY
authors.lastname: Kang
mesh_terms: D000818:Animals; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation; D004195:Disease Models, Animal; D005260:Female; D005341:Fibrinolysin / Q000008:administration & dosage; D005451:Fluorescein Angiography; D006821:Hyaluronoglucosaminidase / Q000008:administration & dosage; D058449:Intravitreal Injections; D008297:Male; D008866:Microsurgery; D013508:Ophthalmologic Surgical Procedures; D012169:Retinal Vein / Q000503:physiopathology / Q000601:surgery*; D012170:Retinal Vein Occlusion / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D013552:Swine; D013556:Swine, Miniature; D014821:Vitrectomy; D014822:Vitreous Body / Q000187:drug effects; D020255:Vitreous Detachment / Q000209:etiology
chemical_list: D006821:Hyaluronoglucosaminidase; D005341:Fibrinolysin
keywords: Intraoperative video fluorescein angiography; TKP vitrectomy; living porcine eye; retinal vein bypass surgery