Intraoperative Endoluminal Quality Control of Saphenous Vein Grafts with Optical Coherence Tomography in Coronary Artery Bypass Grafting
28 January 2019 (online)
Introduction: During bypass surgery, saphenous vein grafts (SVGs) remain a widely used conduit. From earlier studies, we know that graft harvesting can lead to endothelial lesions which result in graft failure or poor quality of anastomosis. There is no intraoperative endothelial quality control durable, which enables the assessment of the inner layer of the vein, the inner diameter, and morphologic disorders endoluminal including venous valves. We need a fast, dynamic and direct control for conduit and anastomosis intraoperative. Optical coherence tomography (OCT) with its very high resolution in time and space offers a new possibility to evaluate luminal features and the vessel wall. In this pilot trial, intraoperative intraluminal assessment of the graft was done after endoscopic vein harvesting during off-pump coronary bypass grafting (OPCAB).
Methods: We included nine patients undergoing OPCAB surgery. After endoscopic vein harvesting, we clipped all side branches and introduced a vessel cannula. After, administration of 0.9% physiologic saline solution to assess the region of interest blood free. When OCT catheter is inside the vein, it was pulled back at 10 mm/s, while images were acquired at 100 frames/s in real time. Maximal length of 5 cm. SVG of 30 cm is recorded six times within 30 seconds at least. Additionally, we operated on seven pigs on-pump beating heart. After harvesting of the internal mammary artery, we were able to get visualization of graft and anastomosis.
Results: In this pilot trail, 60 video sequences with a length of 5 cm each were recorded with total assessment length of 3 m. In two sequences, we found blow outs with aneurysmatic dilatation. In three sections, dysmorphic venous valves were indicated. We found no endothelial lesions except at the end of the SVGs at the resection area.
Direct visualization of anastomosis in pigs showed good quality of suture and in one pig microthrombus on the anastomosis.
Conclusion: OCT assessment is the only method for dynamic and direct visualization of conduits and anastomosis. Penetration of soft tissue and vessel wall is excellent. Procedure is safe, fast, and easy to handle.
Intraoperative findings can lead to graft adjustment or revision of anastomosis to assure best quality for the patient.
No conflict of interest has been declared by the author(s).