Early ostial saphenous vein graft stenosis associated with the use of Symmetry sutureless aortic proximal anastomosis device: Successful percutaneous revascularization

Establishment of an animal model of vascular restenosis with bilateral carotid artery grafting

Background

Vascular restenosis occurring after CABG is a major clinical problem that needs to be addressed. Vein grafts are associated with a higher degree of stenosis than artery grafts. However, the mechanism responsible for this effect has not been elucidated. We aimed to establish a rabbit model of vascular restenosis after bilateral carotid artery grafting, and to investigate the associated spatiotemporal changes of intimal hyperplasia in carotid artery and jugular vein grafts after surgery.

Material/Methods

Twenty adult New Zealand white rabbits (10 males; 10 females), weighing 2.0–2.5 kg, were obtained from the Experimental Animal Center of Southern Medical University, Guangzhou, China (License No.: scxk-Guangdong-2006-0015). We quantitatively analyzed intimal thickness, area, and degree of stenosis in carotid artery and jugular vein bridges.

Results

After 8 weeks of a high-fat diet, rabbit carotid arteries showed early atherosclerotic lesions. With increasing time after surgery, carotid artery and jugular vein grafts showed histopathological and morphological changes, including smooth muscle cell migration, lipid deposition, intimal hyperplasia, and vascular stenosis. The degree of vascular stenosis was significantly higher in vein grafts than in artery grafts at all time points – 35.1±6.7% vs. 16.1±2.6% at Week 12, 56.2±8.5% vs. 23.4±3.4% at Week 16, and 71.2±1.3% vs. 25.2±5.3% at Week 20.

Conclusions

Rabbit bilateral carotid arteries were grafted with carotid artery and jugular vein bridges to simulate pathophysiological processes that occur in people after CABG surgery.

Mid-term follow up of patients using the St. Jude Medical Aortic Connector System for proximal vein graft in CABG

The aortic connector system may reduce stroke during proximal venous anastomosis. However, the overall anastomotic patency rate has been generally reported to be low. From October 2002 to March 2004, 68 patients who received proximal anastomosis using the St. Jude Aortic Connector System were included in the study. There were 47 men and 21 women and their mean age was 65.68+/-6.68 yr old (52 to 85 yr). Grafts were evaluated by coronary angiography or multi-slice 16 channel 3-D CT at 6 days and at 6 months postoperatively. In the immediate postoperative period, no stenosis was observed by either angiography (n=22) or 3D CT (n=46). At 6-month postoperatively, we performed either angiography (n=7) or 3-D CT (n=52). Of these patients, 5 patients showed graft stenosis in the midportion, and 3 in the ostium. There were no stroke. Simple, and effective proximal anastomosis with good protection from cerebrovascular accident was achieved especially when calcification or atheromatous plaque was observed at the ascending aorta in the operation room. However, our mid term patency results raise concerns related to venous graft stenosis in the midportion. Therefore, longer follow up is recommended.