OBJECTIVE
To determine the effect of the gelatin coating on the efficacy of Gelweave, a new gelatin-sealed woven polyester graft material, as an arterial prosthesis.
DESIGN
In-vitro and in-vivo studies of the prosthesis.
SETTING
A laboratory of experimental surgery in a university teaching institution.
SUBJECTS
After in-vitro testing of the material, eight dogs were subjected to a series of in-vivo tests to evaluate the properties of Gelweave in comparison with its unsealed precursor and a commerically available collagen-coated woven polyester prosthesis.
INTERVENTION
Implantation of the prosthesis as a thoracoabdominal bypass for prescheduled periods ranging from 4 hours to 6 months.
MAIN OUTCOME MEASURES
Physical and chemical properties of the virgin prosthesis compared with the other two prostheses, effects of the gelatin-sealed prosthesis on healing, the hematologic characteristics of the dogs before operation and at sacrifice, microscopic studies, fibrin and platelet uptakes, prostaglandin secretion, and properties of the Gelweave grafts removed at varying periods after implantation.
RESULTS
The gelatin sealant in the Gelweave prosthesis effectively reduced the water permeability of the new prototype to zero. Neither blood loss at implantation nor infection during the postimplantation period was observed. The gelatin impregnation did not cause any adverse response in the dogs and was completely lysed within 2 weeks, thus allowing encapsulation and graft healing to progress satisfactorily. After 2 weeks, the prostacyclin:thromboxane ratio was greater than 1.0, whereas the fibrin and platelet uptakes on the luminal surface of the Gelweave grafts remained low, regardless of the period of implantation. Analysis of the explanted grafts confirmed that this gelatin-sealed prototype prosthesis healed satisfactorily and no adverse biologic response occurred as a result of the gelatin coating. It maintained its biostability during 6 months in situ.
CONCLUSION
The new Gelweave arterial prosthesis is ready for clinical use as a thoracic and abdominal vascular substitute.