Abstract
The Palmaz stent was placed in the trachea and mainstem bronchi of 10 healthy beagle dogs. Stent size was estimated from thoracic radiographs in awake dogs. Group I dogs (n=4) had two stents placed: one in the thoracic trachea (TT) plus a randomly chosen mainstem bronchus (MB). Group R dogs (n=3) also had a stent placed in the mid-or proximal cervical trachea (CT). Three dogs were used as sham-operated controls (Group HI). Temperature, pulse, respiration, and cough were measured twice daily. Dogs were evaluated at 21 and 49-56 days after stent placement, euthanized, and tissues were harvested for histomorphometric analysis of stent integration and epithelial pathology. Mean tracheal diameters of awake (10.51︢.7 mm) and anesthetized dogs prior to stent implantation (13.92︢.0 mm) were.significantly different (P<0.01). Complications associated with stent placement included acute pulmonary edema (n=2), stent rfflgration (n=7), stent collapse (n=4 CT, 2 TT, and 1 MB), and positive tracheal culture (n=10). Group R dogs coughed more at rest, exercise, and with tracheal palpation than dogs in other groups (P<0.01). Group I dogs coughed more at rest than Group HI dogs (P<0.01). Stent integration ranged from 0-91.33%. Squamous metaplasia associated with stents ranged from 0-57.53%; epithelial ulceration ranged from 0-32.73%. Determnation of stent sized should be based on measurements taken on anesthetized dogs because use of inappropriately sized stents may promote stent migration, squarnous metaplasia, and/or ulceration. Epithelialization over stent struts may occur if the stent is closely associated with the tracheal epithelium. Palmaz stents do not appear to be appropriate for placement in the CT; however, with technical modifications, application in the TT and MB may be feasible.
Radlinsky, Maryann Gerise (1996). Evaluation of the Palmaz stent in the trachea and bronchi of normal dogs. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1996 -THESIS -R33.