Experimental study of a new tracheal prosthesis: Pored Dacron tube

Abstract

Objective This study was designed to evaluate how various sizes and densities of pores in Dacron tubing might enhance its utility as a tracheal prosthesis. Methods A vascular prosthesis made of knitted external velour polyester was prepared for pore formation with a laser. The first set compared different pore sizes (300, 500, and 700 μm) and pore densities (25/cm 2 or 100/cm 2). Grafts were reinforced with an externally heat-sealed silicone ring. The second set tested grafts with a pore density of 64/cm 2 and a pore size of 500 μm internally reinforced with a stainless-steel spiral stent. In all experiments, a canine mediastinal trachea 10 cartilage rings in length was resected, and the prosthesis was then implanted with an omental flap. Results Lower pore size and density (300 μm, 25 pores/cm 2) led to essentially no tissue ingrowth. Larger pore size (700 μm) and low density (25 pores/cm 2) led to rapid and excessive ingrowth of granulation. Midrange pore size (500 μm) and high density (100 pores/cm 2) invited steady tissue ingrowth, but marked luminal stenosis eventually developed. Stent-reinforced prostheses with 500-μm pores at 64 pores/cm 2, as used in the second set, maintained an average patency rate of 60% or more (range, 20%-100%) at least 12 months after implantation. Conclusion Our data show that porosity is a key factor for tissue growth through our Dacron tracheal prostheses. This artificial trachea model has led to long-term survivors up to 27 months after the operation and seems promising as a basic model for clinical tracheal repair.