| Objective:To evaluate the safety and efficiency of local paclitaxel delivery using the double-balloon perfusion catheter before stent implantation in the dog coronary artery.Method:The intervention was performed on 20 domestic dogs (weight, 20-25 kg). The animals were randomized to the experimental group (15) and control group (5).The animals underwent the procedure under general anesthesia. A single bolus of heparin (5,000 U) was given intravenously during the intervention. A EBU 3.5 PTC A guide catheter was advanced to the aortic root and engaged under fluoroscopic guidance into the left main coronary artery. After the placement of a 0.0140 guidewire (BMW) into the target artery (LAD or LCX), then injurying the target artery with balloon.The double-balloon perfusion catheter was advanced to the suitable portion of the vessel. Using a handheld syringe with pressure monitoring, experimental group with Paclitaxel (10ml 20umol/L) and control group with normal sodium (10ml) were infused with a low pressure (4-6 atm) to allow for replacement of the escaping drug in the intervention area. The duration of local drug dilivery was 26.45±5.18 second. After local drug dilivery, a 3.0×8mm 316L stainless steel LP-STENT (Boston Scientific) was implanted with 8 atm at the previous treatment area, which could be identified by the impressions of the two balloons. Following stent implantation, a final angiogram was taken for documentation. After removal of the sheath, the femoral arteriotomy was ligated. The incision was closed using standard techniques. Dogs were returned to routine care, including daily monitoring. Animals underwent coronary angiography, Optical Coherence Tomography (OCT) and were sacrificed 90 days after the intervention. The heart was immediately removed and the target vessel was perfusion with physiological saline and fixed at physiological pressures (10%buffered formalin). The arterial segments that contained the stents were removed. The segments were preparation for histologic quantitative assessment.The following parameters were assessed:neointimal thickness (mm) luminal area (mm2), neointimal area(mm2), internal elastic lamina area(mm2), external elastic lamina area(mm2), extent of stenosis (%)Result:All the experimental animal were survival,one stent was lost in an experimental group animal. The angiography showed the rate of restenosis in experimental group was 28.57%comparision with control group was 60%。The result of OCT showed in experimental group the average neointimal thickness was 0.16±0.03 mm, the neointimal area was 1.38±0.36mm2, the lumen area was 3.64±0.56mm2, the extent of stenosis was 27.40±4.56%,in control group the average thickness of the neointima was 0.38±0.03 mm, the neointima area was 2.51±0.47 mm2, the lumen area was2.78±0.57mm2, the extent of stenosis was 47.40±4.50%. The distinction of all the variance above was significance between the two groups. The histologic parameters showed in experimental group the average thickness of the neointima was 0.22±0.09 mm, the neointima area was 1.69±0.79mm2, the lumen area was 3.07±0.49mm2, the extent of stenosis was 33.93±9.99%, in control group the average thickness of the neointima was 0.38±0.03 mm, the neointima area was 2.51±0.47 mm2, the lumen area was2.78±0.57mm2, the extent of stenosis was 65.40±8.23%. The distinction of all above was also significance between the two groups. The stents of both the groups were fully endothelialization. No thrombus and aneurysm were found in stents。Conclusion:Local delivery of paclitaxel with the Double-Balloon perfusion cathete system could inhibit the proliferation of coronary smooth muscle cell and endothelial cell and reduce the rate of restenosis in coronary stents and did not emerge unendothelialization, thrombus, aneurysm in-stnet. It proved that local delivery of paclitaxel was safe and efficient in preventing restenosis in the coronary stents. |
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