Granulation encapsulated stent: a new therapeutic approach for vascular implantation

Effects of paclitaxel intervention on pulmonary vascular remodeling in rats with pulmonary hypertension

The aim of the present study was to investigate the effects of paclitaxel (PTX), at a non-cytotoxic concentration, on pulmonary vascular remodeling (PVR) in rats with pulmonary hypertension (PAH), and to explore the mechanisms underlying the PTX-mediated reversal of PVR in PAH. A total of 36 rats were divided into control group (n=12), model group (n=12) receiving a subcutaneous injection of monocrotaline (60 mg/kg) in the back on day 7 following left pneumonectomy and PTX group (n=12) with PTX (2 mg/kg) injection via the caudal vein 3 weeks following establishing the model. The degree of PVR among all groups, as well as the expression levels of Ki67, p27^Kip1 and cyclin B1, were compared. The mean pulmonary artery pressure, right ventricular hypertrophy index [right ventricle/(left ventricle + septum) ratio] and the thickness of the pulmonary arterial tunica media in the model group were 58.34±2.01 mmHg, 0.64±0.046 and 65.3±3.3%, respectively, which were significantly higher when compared with 23.30±1.14 mmHg, 0.32±0.028 and 16.2±1.3% in the control group, respectively (P<0.01). The mean pulmonary artery pressure, right ventricular hypertrophy index and thickness of the pulmonary arterial tunica media in the PTX group were 42.35±1.53 mmHg, 0.44±0.029 and 40.5±2.6%, respectively, which were significantly lower when compared with the model group (P<0.01). Compared with the control group, the expression levels of Ki67 and cyclin B1 in the model group were significantly increased (P<0.01), while p27^Kip1 expression was significantly reduced (P<0.01). Following PTX intervention, the expression levels of Ki67 and cyclin B1 were significantly reduced when compared with the model group (P<0.01), while p27^Kip1 expression was significantly increased (P<0.01). The results of the present study suggest that PTX, administered at a non-cytotoxic concentration, may reduce PAH in rats, and prevent the effects of PVR in PAH. These effects of PTX may be associated with increased expression of p27^Kip1 and decreased expression of cyclin B1.

Prewire channel stent: a novel stent for bifurcation lesions in a pig model

AIMS

Avoiding side branch occlusion is challenging when treating bifurcation lesions. A newly designed stent system called the prewire channel stent (PWCS) with a side channel positioned between the metallic mesh material and the balloon is introduced. We aimed to compare the time taken to position the PWCS against that for a conventional stent.

METHODS AND RESULTS

The PWCS and a conventional stent were used in a pig model. The time taken from the starting point with the stent outside the body to reaching the bifurcation of the vessel ready for further procedures such as balloon dilatation through the stent mesh opening and double kissing balloon technique, etc., was compared in the conventional stent and PWCS groups. The time taken in the PWCS stent group included the time from sending the stent from outside the body to the desired position of the bifurcation of the vessels of the heart, releasing the stent and pulling back the balloon (SB time). The time taken in the conventional stent included the time from sending the stent from outside the body to the desired position of the bifurcation of the vessels of the heart, releasing the stent, pulling back the balloon (SB time), and wire exchange (WE time). The SB times for the PWCS and the conventional stent groups were not different (28.5±3.8 vs. 25.25±0.75 seconds, n=4). The PWCS group did not have "wire exchange," and had no WE time, which was 28.5±5.7 seconds in the conventional stent group. The total time spent in the PWCS group was 28.5±3.8 seconds, which was shorter than the 53.75±6.2 seconds (n=4, p<0.05) in the conventional stent group.

CONCLUSIONS

The PWCS makes "wire exchange" in the side branch (SB) unnecessary and it can be as easily manipulated as a conventional stent.