Modification of the descending thoracic aortic anastomotic site using biodegradable felt: study in a canine model with or without basic fibroblast growth factor.
OBJECTIVE
We investigated the outcomes of reinforcing anastomotic sites using (1) nonbiodegradable polytetrafluoroethylene (PTFE) felt, (2) biodegradable polyglycolic acid (PGA) felt, and (3) PGA felt with basic fibroblast growth factor (bFGF) in a canine descending thoracic aortic replacement model.


METHODS
Thirty-seven beagles underwent descending thoracic aorta replacement using a prosthetic graft with one of the above-mentioned reinforcements or no reinforcement for controls. Histologic evaluations were carried out 1 month and 3 months after surgery. The biomechanical strength of the anastomosis was assessed along the longitudinal axis of the aortic segments using a tensile tester. Local compliance at the anastomotic site was also evaluated in the circumferential direction.


RESULTS
The media was significantly thinner in the PTFE group than in the control group (65.8% +/- 5.1% vs 95.0% +/- 9.3% of normal thickness; P < .05). Relative to the control group, the adventitial layer was significantly thinner in the PTFE group (42.3% +/- 8.2% of control; P < .05) but significantly thicker in the PGA and the PGA + bFGF groups (117.2% +/- 11.3% and 134.1% +/- 14.2% of control, respectively; P < .05). There were more vessels in the adventitial layer in the PGA + bFGF group than in the control, PTFE, and PGA groups (29.2 +/- 2.1/mm(2) vs 13.8 +/- 0.8, 5.4 +/- 0.7, 17.0 +/- 1.3/mm(2), respectively; P < .01). There were no significant differences between the four groups in the failure force at anastomotic sites. Local compliance at the anastomotic site was higher in the PGA group than that in the PTFE group (11.6 +/- 1.6 10(-6) m(2)/N vs 5.6 +/- 1.9 10(-6) m(2)/N; P < .05).


CONCLUSIONS
Reinforcement of the experimental aortic wall with PTFE felt resulted in thinning of the media and adventitia and fewer vessels at the anastomotic site. These histologic changes were not observed when biodegradable felt was used. The bFGF failed to augment the modification of the aortic wall with the exception of increased adventitial vessel number. Biomechanical strength of the anastomosis along the longitudinal axis was comparable in all four groups; however, local vascular compliance was better in the biodegradable PGA felt group.
Fujiwara
Hidenori
H
Department of Cardiovascular Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan.
Saiki
Yoshikatsu
Y
Sato
Mitsuru
M
Sakamoto
Naoya
N
Ohashi
Toshiro
T
Sato
Masaaki
M
Tabata
Yasuhiko
Y
Tabayashi
Koichi
K
D020341:Absorbable Implants; D000714:Anastomosis, Surgical; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000473:pathology / Q000601:surgery*; D001696:Biomechanical Phenomena; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D003187:Compliance; D003238:Connective Tissue / Q000098:blood supply / Q000187:drug effects / Q000601:surgery; D004285:Dogs; D004337:Drug Carriers; D019544:Equipment Failure Analysis; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D008422:Materials Testing; D023421:Models, Animal; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D011100:Polyglycolic Acid; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013718:Tensile Strength; D017540:Tunica Media / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D014945:Wound Healing / Q000187:drug effects*
D004337:Drug Carriers; D016222:Fibroblast Growth Factor 2; D011100:Polyglycolic Acid; D011138:Polytetrafluoroethylene