Fibrocollagen-covered prosthesis for a noncircumferential segmental tracheal replacement
Received 12 May 2008; received in revised form 10 February 2009; accepted 3 April 2009. published online 24 June 2009.
Objective
Fibrocollagen-covered polyester meshes can be used as possible substitutions for tracheal segments if they become integrated into the tissue without complications. The aim of this study was to assess a fibrocollagen-covered polyester prosthesis to be used as a substitution for a tracheal segment.
Methods
We performed a blind, randomized experimental assay. Adult Wistar rats were assigned to one of 2 groups. Prostheses were made by implanting polyester tubing in a group of animals to cover them with homologous collagen. They were implanted as substitutions of tracheal segments in the experimental group after creating a defect in the anterior wall of the trachea. Clinical, histomorphologic, and immunohistochemical assessments were made at 4 different time points.
Results
The experimental group presented some respiratory distress signs during the first 7 to 10 days, such as stertors, hissing, and low motor activity. After this initial period, the symptoms subsided progressively and disappeared at the end of the first month. These respiratory symptoms caused no mortality. Initially undifferentiated monolayer cells predominated on the implant's surface, but during the last 2 months, the proportion of epithelial and ciliated cells was similar to that seen in control animals. Types I, III, and V collagen fibers were identified around the mesh. The intraluminal area of the tracheas with prostheses and prosthesis thickness were larger during the 4 months of the experiment. The increase in thickness was due to angiogenesis without evidence of fibrosis or chronic inflammation.
Conclusions
Polyester-collagen prostheses used as substitutions of tracheal segments in rats enabled the proliferation of normal respiratory epithelium and maintained tracheal function without collapse, inflammatory reaction, or secondary stenosis.
aExperimental Surgery, Experimental Medicine Division, Instituto Nacional de Pediatría, Mexico
cElectron Microscopy Laboratories, Experimental Medicine Division, Instituto Nacional de Pediatría, Mexico
bDepartment of Surgery, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico
dDepartment of Biochemistry, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico
eDepartment of Cell and Tissue Biology, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico
fDepartment of General Surgery, Hospital General de Mexico, Mexico City, Mexico
Address for reprints: Fernando Villegas-Álvarez, MD, Laboratorio de Cirugía Experimental, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Col Insurgentes Cuicuilco, Delegación Coyoacán, CP 046530, México DF.
ABSTRACT