Validity of Ipsilateral Internal Mammary Coronary Artery Bypass Graft of Arteriovenous Fistula

BACKGROUNDIn coronary artery bypass grafting (CABG) for haemodialysis patients, arteriovenous fistula can reduce blood flow from the internal mammary artery (IMA) graft. The purpose of this study was to delineate the rationale of ipsilateral IMA grafting to the arteriovenous fistula by assessing graft flow and patency. METHODThe clinical records of 139 haemodialysis patients who underwent off-pump CABG, including IMA grafting to the left anterior descending artery (LAD) between April 2007 and December 2018, were retrospectively reviewed. Clinical outcomes and transit-time flowmetry results of IMA to LAD bypass grafts during off-pump CABG and postoperative angiography were examined. RESULTSAn ipsilateral IMA to the arteriovenous fistula (Ipsi-IMA) was used in 89 patients, and a contralateral IMA to the arteriovenous fistula (Contra-IMA) was used in 50 patients and no hospital deaths occurred. The mean graft flow and angiographic patency rate did not differ between the Ipsi-IMA and Contra-IMA groups. In patients with 51 to 90% stenosis of LAD, there was no significant difference in the mean graft flow. In comparison, in the patients with 91 to 100% stenosis of LAD, the mean graft flow in the Ipsi-IMA group was significantly lower than that in the Contra-IMA group (p=0.03). Kaplan-Meier analyses showed a 5-year survival rate of 57.6% for Ipsi-IMA and 64.8% for Contra-IMA (p=0.47). CONCLUSIONSIn the revascularisation of the LAD, the graft patency rate of the Ipsi-IMA was not inferior to that of the Contra-IMA. However, when the LAD has 91 to 100% stenosis, a Contra-IMA to arteriovenous fistula may be beneficial in terms of sufficient flow capacity.