title: A novel biodegradable external mesh stent improved long-term patency of vein grafts by inhibiting intimal-medial hyperplasia in an experimental canine model.
abstract: OBJECTIVE
  Increased hemodynamic stress on vein grafts used in the arterial system is associated with vein graft disease. We determined whether a novel biodegradable external mesh stent could inhibit medial-intimal hyperplasia by suppressing hemodynamic stress on vein grafts and improve long-term patency.
  
  
  METHODS
  Twenty-four beagles underwent bilateral femoral interposition grafting using reversed femoral veins. Vein grafts were externally supported by a novel poly L-lactide-ε-caprolactone copolymer (P(LA/CL)) biodegradable mesh stent or a nonabsorbable mesh stent. Vein grafts with no reinforcement were used as controls. The grafts were harvested 6 and 12 months after implantation for morphometric and immunohistochemical assessment.
  
  
  RESULTS
  The endoluminal circumferential vein graft length was smaller in the P(LA/CL) and nonabsorbable groups (17.2 ± 2.9 and 19.0 ± 0.3 mm, respectively), than that in the control group (25.0 ± 2.6 mm, P < 0.01) at 12 months. The mean intimal-medial thickness was thinner in P(LA/CL) and nonabsorbable stent groups (0.18 ± 0.05 and 0.16 ± 0.05 mm, respectively), than that in the control group (0.30 ± 0.08 mm, P < 0.01). Differences in the intimal-medial thickness among the groups were associated with the magnitude of cellular proliferating activity. The graft patency ratio (100 %) was higher in the P(LA/CL) group than that in the nonabsorbable and control groups (72.2 and 63.6%, respectively, P < 0.05).
  
  
  CONCLUSIONS
  The biodegradable P(LA/CL) external mesh stent improved vein graft patency for 12 months and prevented vein graft dilatation and intimal hyperplasia associated with suppressed neointimal layer cellular proliferating activity.
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Sato
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan. shunsukekawamoto@med.tohoku.ac.jp.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kawamoto
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine, Tohoku University, Sendai, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Goro
authors.initials: G
authors.lastname: Takahashi
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Masaki
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Kumagai
authors.affiliation: Department of Medical Engineering and Cardiology, Tohoku University, Sendai, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Saijo
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Tabayashi
authors.affiliation: Division of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, 1-1 Seiryocho, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Saiki
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002208:Caproates; D004195:Disease Models, Animal; D004285:Dogs; D005263:Femoral Artery / Q000601:surgery; D005268:Femoral Vein / Q000637:transplantation*; D006083:Graft Occlusion, Vascular / Q000517:prevention & control; D006965:Hyperplasia / Q000209:etiology / Q000517:prevention & control; D007783:Lactones; D011474:Prosthesis Design; D015607:Stents; D013526:Surgical Mesh; D017539:Tunica Intima / Q000473:pathology*; D017540:Tunica Media / Q000473:pathology*; D014654:Vascular Patency
chemical_list: D002208:Caproates; D007783:Lactones; C121056:caprolactone
keywords: Biodegradable stent; External support; Intimal hyperplasia; Vein graft