Tailored sizes of constrictive external vein meshes for coronary artery bypass surgery

TY - JOUR

T1 - Tailored sizes of constrictive external vein meshes for coronary artery bypass surgery

AU - Franz, Thomas

AU - Human, Paul

AU - Dobner, Stephan

AU - Reddy, B Daya

AU - Black, Melanie

AU - Ilsley, Helen

AU - Wolf, Michael F

AU - Bezuidenhout, Deon

AU - Moodley, Lovendran

AU - Zilla, Peter

N1 - Copyright © 2010 Elsevier Ltd. All rights reserved.

PY - 2010/12

Y1 - 2010/12

N2 - External mesh constriction of vein grafts was shown to mitigate intimal hyperplasia by lowering circumferential wall stress and increasing fluid shear stress. As under-constriction leaves vein segments unsupported and thus prone to neointimal proliferation while over-constriction may cause wall folding optimal mesh sizing holds a key to clinical success. Diameter fluctuations and the occurrence of wall folding as a consequence of external constriction with knitted Nitinol meshes were assessed in saphenous vein grafts from 100 consecutive coronary artery bypass (CABG) patients. Subsequently, mesh dimensions were identified that resulted in the lowest number of mesh sizes for all patients either guaranteeing tight continual mesh contact along the entire graft length (stipulation A) or preventing wall folding (stipulation B). A mathematical data classification analysis and a statistical single-stage partitioning approach were independently applied alternatively prioritizing stipulation A or B. Although the risk of folding linearly increased when constriction exceeded 24.6% (Chi squared test p = 0.0004) the actual incidence of folding (8.6% of veins) as well as the degree of lumenal encroachment (6.2 ± 2.1%) were low. Folds were always single, narrow longitudinal formations (height: 23.3 ± 4.0% of inner diameter/base: 16.6 ± 18.1% of luminal circumference). Both analytical methods provided an optimum number of 4 mesh sizes beyond which no further advantage was seen. While the size ranges recommended by both methods assured continual tight mesh contact with the vein the narrower range suggested by the mathematical data classification analysis (3.0-3.7 mm) put 20.6 ± 12.5% of length in 69% of veins at risk of folding as opposed to 21.3 ± 25.9% being at risk in the wider size range (3.0-4.2 mm) suggested by the statistical partitioning approach. Four mesh sizes would provide uninterrupted mesh contact in 98% of vein grafts in CABG procedures with only 26% of their length being at risk of relatively mild wall folding.

AB - External mesh constriction of vein grafts was shown to mitigate intimal hyperplasia by lowering circumferential wall stress and increasing fluid shear stress. As under-constriction leaves vein segments unsupported and thus prone to neointimal proliferation while over-constriction may cause wall folding optimal mesh sizing holds a key to clinical success. Diameter fluctuations and the occurrence of wall folding as a consequence of external constriction with knitted Nitinol meshes were assessed in saphenous vein grafts from 100 consecutive coronary artery bypass (CABG) patients. Subsequently, mesh dimensions were identified that resulted in the lowest number of mesh sizes for all patients either guaranteeing tight continual mesh contact along the entire graft length (stipulation A) or preventing wall folding (stipulation B). A mathematical data classification analysis and a statistical single-stage partitioning approach were independently applied alternatively prioritizing stipulation A or B. Although the risk of folding linearly increased when constriction exceeded 24.6% (Chi squared test p = 0.0004) the actual incidence of folding (8.6% of veins) as well as the degree of lumenal encroachment (6.2 ± 2.1%) were low. Folds were always single, narrow longitudinal formations (height: 23.3 ± 4.0% of inner diameter/base: 16.6 ± 18.1% of luminal circumference). Both analytical methods provided an optimum number of 4 mesh sizes beyond which no further advantage was seen. While the size ranges recommended by both methods assured continual tight mesh contact with the vein the narrower range suggested by the mathematical data classification analysis (3.0-3.7 mm) put 20.6 ± 12.5% of length in 69% of veins at risk of folding as opposed to 21.3 ± 25.9% being at risk in the wider size range (3.0-4.2 mm) suggested by the statistical partitioning approach. Four mesh sizes would provide uninterrupted mesh contact in 98% of vein grafts in CABG procedures with only 26% of their length being at risk of relatively mild wall folding.

KW - Adult

KW - Aged

KW - Alloys/therapeutic use

KW - Blood Vessel Prosthesis

KW - Coronary Artery Bypass

KW - Female

KW - Humans

KW - In Vitro Techniques

KW - Male

KW - Middle Aged

KW - Prosthesis Design

KW - Saphenous Vein

KW - Surgical Mesh

KW - Tissue and Organ Harvesting

U2 - 10.1016/j.biomaterials.2010.08.054

DO - 10.1016/j.biomaterials.2010.08.054

M3 - SCORING: Journal article

C2 - 20864157

VL - 31

SP - 9301

EP - 9309

JO - BIOMATERIALS

JF - BIOMATERIALS

SN - 0142-9612

IS - 35

ER -