1-Year Patency of Biorestorative Polymeric Coronary Artery Bypass Grafts in an Ovine Model.

Many attempts have been made to inhibit or counteract saphenous vein graft (SVG) failure modes; however, only external support for SVGs has gained momentum in clinical utility. This study revealed the feasibility of implantation, and showed good patency out to 12 months of the novel biorestorative graft, in a challenging ovine coronary artery bypass graft model. This finding could trigger the first-in-man trial of using the novel material instead of SVG. We believe that, eventually, this novel biorestorative bypass graft can be one of the options for coronary artery bypass graft patients who have difficulty harvesting SVG.

Implantation of the eSVS Mesh: modification of recommended technique.

The eSVS Mesh is a knitted wire lattice manufactured in cylindrical sheaths of various diameters, designed to be placed around the outer surface of a saphenous vein graft before use in coronary surgery. The goal is to improve long-term vein graft patency by preventing expansive endothelial injury obviating neointimal hyperplasia and subsequent graft atherosclerosis. Since the First-In-Man feasibility trial of the eSVS Mesh, postmarket studies in Europe and a feasibility trial in the United States are ongoing. Consensus from the principal investigators indicated the trials had confounding variables that may impact results other than evaluation of the eSVS Mesh alone. With input from these investigators, the recommended operative technique has been modified for future trials by removing the mesh from proximal and distal anastomoses and eliminating the use of fibrin sealant. These changes allow for use of an implant technique closer to standard vein bypass grafting and a more focused evaluation of the eSVS Mesh.

Clinical evaluation of the eSVS Mesh: First-in-Man trial outcomes.

In coronary artery bypass graft surgery, saphenous vein graft (SVG) patency is much lower than that of the internal mammary artery (IMA). To address this problem, an external support device, the eSVS Mesh was developed. A prospective randomized First-in-Man feasibility trial was conducted in 90 patients after institutional ethics committee approval at seven international centers. The left IMA was used to bypass the anterior descending artery. A mesh-supported (treated) saphenous vein was randomized to either the right or the circumflex coronary system, and an unsupported (control) vein was grafted to the opposing territory. Device diameters available for use were 3.0, 3.5, 4.0, and 4.5 mm. Primary end-points were 30 day adverse cardiac and cerebral events and angiographic patency at 9-12 months. Eighty-five of 90 patients returned for 30 day clinical follow-up (94%). Five patients refused to return, but by telephone contacts were asymptomatic. There was one late noncardiac death and 73 patients returned for angiography (82%), thus 12 additional patients were lost to follow-up at 1 year. Overall patency rate was 49% for the treated versus 81% for controls (p < 0.001). Subset analysis revealed significantly lower patency at one center and with use of the 3.0 mm device (p < 0.05). Removing these data, patency was 72% vs. 81% (p = NS). Sternal wound infection was higher than expected at 5.0%, but this was center specific. The eSVS Mesh is safe, but at up to 1 year, patency is equivalent to untreated vein grafts after removal of outlying data. This study provides insight into operative events and parameters that may optimize outcomes and point to potential improvements in the external SVG support device. Furthermore, longer term studies are pending.

Intraoperative transit-time flow measurement is not altered in venous bypass grafts covered by the eSVS mesh.

OBJECTIVE: The aim of this study was to determine whether the eSVS Mesh interferes with transit-time flow measurement (TTFM) assessing intraoperative coronary vein graft patency. METHODS: In four swine undergoing off-pump bypass grafting to the anterior descending coronary artery, five TTFMs were sequentially obtained on meshed and bare grafts at baseline and under Dobutamine stress at five separate locations on the graft in each animal. The Medistim VeriQ was used for TTFM. The grafts were examined for patency after the swine were killed. RESULTS: There was no difference in hemodynamics or TTFM either at baseline or under Dobutamine stress between the eSVS Mesh covered and uncovered grafts. Dobutamine, however, significantly increased hemodynamics and graft flow parameters measured from baseline. CONCLUSIONS: The eSVS Mesh does not interfere with Doppler flow measurement in covered coronary vein grafts.

Implantation of the eSVS Mesh.

The eSVS Mesh (Kipps Bay Medical, Minneapolis, MN USA) Mesh (Kipps Bay Medical, Minneapolis, MN USA) is a new concept in improving saphenous vein graft patency for coronary bypass grafting. This is a nitinol-based external support device that maintains external support of the graft and prevents detrimental expansion when exposed to arterial pressure. The implanting technique is critical to outcomes and is described in this article. Clinical testing in the United States is pending.