Journal
EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY
Volume 44, Issue 1, Pages 64-71Publisher
OXFORD UNIV PRESS INC
DOI: 10.1093/ejcts/ezs670
Keywords
Vein grafts; Coronary bypass; Knitted nitinol mesh; Intimal suppressive
Funding
- South African Medical Research Council (MRC)
- National Research Foundation in South Africa (NRF)
- Medtronic Inc. (Minneapolis, Minnesota)
Ask authors/readers for more resources
OBJECTIVES: Different flow patterns and shear forces were shown to cause significantly more luminal narrowing and neointimal tissue proliferation in coronary than in infrainguinal vein grafts. As constrictive external mesh support of vein grafts led to the complete suppression of intimal hyperplasia (IH) in infrainguinal grafts, we investigated whether mesh constriction is equally effective in the coronary position. METHODS: Eighteen senescent Chacma baboons (28.8 +/- 3.6 kg) received aorto-coronary bypass grafts to the left anterior descending artery (LAD). Three groups of saphenous vein grafts were compared: untreated controls (CO); fibrin sealant-sprayed controls (CO + FS) and nitinol mesh-constricted grafts (ME + FS). Meshes consisted of pulse-compliant, knitted nitinol (eight needles; 50 mu m wire thickness; 3.4 mm resting inner diameter, ID) spray attached to the vein grafts with FS. After 180 days of implantation, luminal dimensions and IH were analysed using post-explant angiography and macroscopic and histological image analysis. RESULTS: At implantation, the calibre mismatch between control grafts and the LAD expressed as cross-sectional quotient (Q(c)) was pronounced [Q(c) = 0.21 +/- 0.07 (CO) and 0.18 +/- 0.05 (CO + FS)]. Mesh constriction resulted in a 29 +/- 7% reduction of the outer diameter of the vein grafts from 5.23 +/- 0.51 to 3.68 +/- 0 mm, significantly reducing the calibre discrepancy to a Q(c) of 0.41 +/- 0.17 (P < 0.02). After 6 months of implantation, explant angiography showed distinct luminal irregularities in control grafts (ID difference between widest and narrowest segment 74 +/- 45%), while diameter variations were mild in mesh-constricted grafts. In all control grafts, thick neointimal tissue was present [600 +/- 63 mu m (CO); 627 +/- 204 mu m (CO + FS)] as opposed to thin, eccentric layers of 249 +/- 83 mu m in mesh-constricted grafts (ME + FS; P < 0.002). The total wall thickness had increased by 363 +/- 39% (P < 0.00001) in CO and 312 +/- 61% (P < 0.00001) in CO + FS vs 82 +/- 61% in ME + FS (P < 0.007). CONCLUSIONS: In a senescent non-human primate model for coronary artery bypass grafts, constrictive, external mesh support of saphenous veins with knitted nitinol prevented focal, irregular graft narrowing and suppressed neointimal tissue proliferation by a factor of 2.5. The lower degree of suppression of IH compared with previous infrainguinal grafts coincided with a lesser reduction of calibre mismatch in the coronary grafts.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available