Evaluation of very early neointimal coverage post drug-eluting stent implantation using optical coherence tomography / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the neointimal coverage at the very early phase after drug-eluting stent (DES) implantation using optical coherence tomography (OCT).</p><p><b>METHODS</b>OCT examination was performed immediately after stent deployment and about one week post stenting in 12 patients with coronary artery disease to detect neointimal coverage and stent thrombus. Sirolimus eluting stent implantation was also performed in 5 healthy Chinese minipigs, OCT and histopathology examination were made one week later in these minipigs.</p><p><b>RESULTS</b>(1) Twenty-nine DES were implanted in 12 patients. There was no major cardiovascular event post stenting. The mean time of follow-up was (7.7 ± 2.6) d, the mean percentage of stent coverage was (21.8 ± 17.7)%, and neointimal hyperplasia thickness was (42.9 ± 32.2) µm and the percentage of malapposition struts was (1.5 ± 3.0)%, respectively. Mural stent thrombus was found in 2 of the 12 patients (the percentage is 16.7%). (2) In the minipigs model, OCT evidenced that (43.2 ± 11.5)% struts were covered by neointima with a mean neointimal hyperplasia thickness of (24.0 ± 8.5) µm at one week. Histopathology examination illustrated that the neointima was mainly consisted of proteoglycan, inflammation cells, fibrin and organized thrombus at the very early phase after DES implantation, while endothelial cells were barely found on the neointima.</p><p><b>CONCLUSIONS</b>Neointimal coverage is found as early as one week after DES implantation by OCT. The covered struts rate is very low and the main components of neointima are proteoglycan, inflammation cells, fibrin and organized thrombus. Re-endothelialization is rather poor at the very early phase post DES implantation.</p>

Relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model.</p><p><b>METHODS</b>Twenty normal minipigs were randomly divided into group A (implanted with 316L bare metal stents), group B (implanted with 605L bare metal stents), group C (implanted with PLGA coating 605L stents), and group D (implanted with rapamycin-loaded PLGA coating 605L stents). Each minipig was implanted with two same stents in left anterior descending artery and right coronary artery. Four weeks later, the animals were sacrificed and histomorphometric measurements on the stent-segment coronary arteries were made to calculate the correlation between inflammation area and neointimal area.</p><p><b>RESULTS</b>Group D had the smallest neointimal area [(0.64 +/- 0.38) mm2, P < 0. 001] and inflammation area (median 0.00 mm2, P = 0.009) among all the groups, while there were no statistical differences among group A, B, and C in neointimal area [(2.09 +/- 0.90), (2.11 +/- 1.07), and (1.42 +/- 0.35) mm2 respectively] and in inflammation area (0.22 , 0.21, and 0.09 mm2, respectively). Bivariate correlation analysis showed that the inflammation area was positively correlated with the neointimal area (P < 0.001, correlation coefficient = 0.719). When stent type, mean injury score, and EEL area were adjusted, partial correlations analysis showed that the inflammation area was still positively correlated with the neointimal area (P = 0.01, correlation coefficient = 0.498).</p><p><b>CONCLUSION</b>Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.</p>

Chronic sheep modal for pulmonary valve implantation with domestic bileaflet mechanical prosthesis / 中华外科杂志

<p><b>OBJECTIVE</b>The aim of this study was to identify the long-term character of the domestic bileaflet mechanical valve in the chronic implanted sheep model and to evaluate the potential value of the modal.</p><p><b>METHODS</b>Six adult sheep underwent implanted mechanical bileaflet valve in pulmonary position under the cardio-pulmonary bypass with beating heart. The chronic implanted sheep model was built up and observed in the respects of a long-term survival, function of prosthesis and pathological specimen.</p><p><b>RESULTS</b>Six adult sheep survived with good condition after operation. The average survival period of six sheep was (221 +/- 208) days. Two sheep were postoperatively sacrificed in 41 and 71 days, respectively. The necropsy revealed normal valve function without thrombosis, periprosthetic leakage and overgrowth of fibrous tissue. One sheep died from dysfunction of prosthetic valve at the postoperative 196 days. The reason was the prosthetic thrombosis with slight overgrowth of fibrous tissue in periprosthesis. The other two sheep died from severe anemia at the postoperative 196 days and 234 days, and the autopsy revealed no abnormal finding else. And one remained to survive with good condition up to now (over 617 days) and was checked by Doppler echocardiogram twice at the postoperative 438 days and 479 days, respectively. The results showed normal function of the bileaflet valve in pulmonary position.</p><p><b>CONCLUSION</b>The long-term good effects would be achieved by using the implanted new domestic bileaflet valve in pulmonary position of sheep.</p>