Abstract 482: Early Reduction of Blood Flow in Rabbit Jugular Vein-Carotid Artery Bypass Grafts is not Caused by Anastomotic Stenosis
| Autor: | Kaushik Komandur, Lianxiang Bi, Bradley K Wacker, David A Dichek |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Arteriosclerosis, Thrombosis, and Vascular Biology. 42 |
| ISSN: | 1524-4636 1079-5642 |
| DOI: | 10.1161/atvb.42.suppl_1.482 |
| Popis: | Background: Obstructed arteries are often treated by surgical implantation of venous bypass grafts. Vein grafts can fail for many reasons, including thrombosis, atherosclerosis, or anastomotic stenoses (narrowings where the grafts connect to the artery). In a previous study aimed at developing a hyperlipidemic rabbit model of vein-graft atherosclerosis for testing gene therapy, vein grafts used to bypass carotid arteries were widely patent. However, vein graft blood flow decreased by a mean of 5.6 mL/minute (~23%) between 8 and 16 wks after grafting, with flow at 16 wks reduced to Methods: We designed an experiment to test whether anastomotic stenoses were present and—if so—whether the stenoses were the cause of decreased blood flow. In a new set of grafted veins, we harvested the anastomoses, embedded, sectioned and stained them, and measured percent stenosis using computer-assisted image analysis. Percent stenosis was calculated by dividing intimal area by the stenosis-free lumen area (calculated from the length of the IEL, assuming circular geometry in vivo). We measured stenoses in both anastomoses of 22 patent vein grafts, harvested from 14 hyperlipidemic rabbits (44 total anastomoses). Blood flow (mL/min) in each vein graft was measured with a flow meter at 4 wks after grafting and again at 16 wks (at harvest). Results: The mean blood flow at the 4 wks measurement was 51 mL/minute (range: 28 to 90) and 36 mL/minute (range: 21 to 53) at the harvest measurement. The calculated mean change in blood flow was –16 mL/minute (range: –55 to +14). The mean anastomotic stenosis was 39% (range: 2.3% to 89%). Using Spearman’s rank-order correlation test, we found that percentage stenosis did not correlate with the change in blood flow (r=0.059; P=0.8). Conclusions: Decreased blood flow in our vein graft model is likely not caused by anastomotic stenoses. Other explanations, such as decreased cardiac output or increased downstream vascular resistance (caused by cerebral atherosclerosis or microemboli) should be considered. |
| Databáze: | OpenAIRE |
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