Abstract 1810: Angiographic Evidence for Reduced Graft Patency Due to Competitive Flow in Composite Arterial T-Grafts
Background: Composite arterial T-grafting (CTG) causes splitting of Internal Thoracic Artery (ITA) flow. The amount of flow supplying each region depends on severity of coronary stenosis. Competitive flow in native coronary vessel can cause occlusion of the composite’s arm supplying this vessel.
Materials and Methods: One hundred and fifty seven consecutive postoperative coronary angiographies of patients who underwent CTG with bilateral ITA were compared with preoperative angiograms. Angiographies were done in symptomatic patients or patients with positive thalium scan between two and 98 months after surgery.
Results: In 122 patients both ITAs were patent. The remaining 35 postoperative angiograms had at least one occluded ITA. Using multivariable logistic regression, Left Anterior Descending (LAD) stenosis of less than 70% was associated with higher left ITA occlusion rate (p< 0.025, OR 4.8, 95%CI 1.2–19). Circumflex stenosis of less than 70% was associated with higher right ITA occlusion rate (p < 0.001, OR 5.8, 95% CI 2–17). Left ITA occlusion was also affected by the degree of stenosis in the Circumflex and LAD when Left Main (LM) stenosis was less than 50%. LM stenosis of less than 50% was associated with higher left ITA occlusion when LAD stenosis was less than 50% (OR 24 95% CI 4–164, p< 0.001) and higher right ITA occlusion when Circumflex stenosis was less than 50% (OR 17 95% CI 5–57, p< 0.004).
Conclusion: The CTG technique of bilateral ITA grafting should be reserved for patients with severe (70% or more) LAD and circumflex stenosis.