title: Experimental noninferiority trial of synthetic small-caliber biodegradable versus stable vascular grafts.
abstract: OBJECTIVE
  Long-term evolution of polycaprolactone vascular prostheses has been investigated recently. The goal of this study was to evidence a noninferiority of such grafts compared with expanded polytetrafluoroethylene (ePTFE) implants in an aortic replacement model in the rat.
  
  
  METHODS
  Fourteen anesthetized Sprague-Dawley rats received an infrarenal aortic graft (biodegradable, n = 8; expanded polytetrafluoroethylene, n = 6) replacement (end to end; inner diameter, 2 mm). Biodegradable grafts (polycaprolactone) were produced by random micro-/nanofiber electrospinning. After a median survival of 16.5 months, in vivo ultrasonography and angiography as well as postexplantation microcomputed tomography, histomorphometry, immunohistochemistry, and scanning electron microscopy were performed.
  
  
  RESULTS
  Patency was 100% for polycaprolactone and 67% for ePTFE. No aneurysmal dilatation or stenoses were found in either group. Compliance was significantly higher for polycaprolactone compared with ePTFE (8.2 ± 1.0%/100 mm Hg vs 5.7 ± 0.7%/100 mm Hg; P < .01), but markedly reduced compared with adjacent native aortas and the control group. Histologically, low cellular in-growth was found in ePTFE whereas polycaprolactone showed significantly greater homogenous cellularity, producing an autologous extracellular matrix (10.8% ± 4.0% vs 32.1% ± 9.2%, P < .0001). Morphometry showed 100% neo-endothelialization for both grafts with a totally confluent endothelial coverage for polycaprolactone grafts by scanning electron microscope. More intimal hyperplasia was found in ePTFE compared with polycaprolactone grafts. Calcification was higher in ePTFE than in polycaprolactone grafts (15.8% vs 7.0%, P = .04) and was absent in controls.
  
  
  CONCLUSIONS
  Outcomes of synthetic biodegradable nanofiber polycaprolactone grafts are not inferior compared with the clinically used expanded polytetrafluoroethylene grafts after long-term implantation in the rat aorta. Moreover, these implants show better patency, compliance, endothelialization, and cell in-growth, and less intimal hyperplasia and calcification than their counterparts.
authors.affiliation: Service of Cardiovascular Surgery, Faculty of Medicine, University Hospital, Geneva, Switzerland.
authors.forename: Damiano
authors.initials: D
authors.lastname: Mugnai
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Tille
authors.forename: Wojciech
authors.initials: W
authors.lastname: Mrówczyński
authors.forename: Sarra
authors.initials: S
authors.lastname: de Valence
authors.forename: Xavier
authors.initials: X
authors.lastname: Montet
authors.forename: Michael
authors.initials: M
authors.lastname: Möller
authors.forename: Beat H
authors.initials: BH
authors.lastname: Walpoth
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery* / Q000648:ultrastructure; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D003187:Compliance; D003251:Constriction, Pathologic; D042783:Endothelial Cells / Q000648:ultrastructure; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D006965:Hyperplasia; D007150:Immunohistochemistry; D008297:Male; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D057139:Nanofibers; D011091:Polyesters; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D061205:Vascular Calcification / Q000209:etiology / Q000473:pathology; D014654:Vascular Patency; D055114:X-Ray Microtomography
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D011138:Polytetrafluoroethylene
keywords: ECM; PCL; ePTFE; expanded polytetrafluoroethylene; extracellular matrix; polycaprolactone