Background: The purpose of this study was to investigate in vivo the arterial wall temperature after coronary stent implantation in pigs.
Methods: We performed cardiac catheterization in 20 pigs with normal coronary arteries. Arterial wall temperature was studied with a thermography system that uses a 4-thermistor sensor tip. A segment was selected in the proximal right coronary artery. Temperature was mapped in this segment by means of a continuous catheter pullback. A stent was then implanted in the middle of this area, and the temperature scan was repeated. Pigs were randomized in two groups (10 + 10 pigs) for arterial temperature scanning: group A to be re-scanned after 5 days and then sacrificed, and group B to be re-scanned after 8 days and then sacrificed.
Results: The temperature of the arterial wall before stent implantation was equal to the adjacent areas. Immediately after stent implantation, the stented area had lower temperature than the adjacent areas (p < 0.001). Five days after implantation, the stented area was significantly warmer than the adjacent areas (p < 0.001); histopathology showed the highest macrophage population at the place of the stent. Eight days after implantation, the temperature differences were reduced to non-significant levels (p = NS) and the macrophage population was significantly lower.
Conclusion: Stent implantation results in an immediate temperature decrease at the stented arterial segment, followed by a significant temperature increase around day 5 after stent implantation. These findings can be correlated with the peri-strut inflammation that follows the stent implantation.