The Validity of Ipsilateral Internal Mammary Coronary Artery Bypass Graft of Left Upper Extremity Arteriovenous Fistula
Jun Hayashi, Hiroyuki Nakajima, Akitoshi Takazawa, Fumiya Chubachi, Yuto Hori, Takashi Hashimoto, Chiho Tokunaga, Toshihisa Asakura, Atsushi Iguchi, Akihiro Yoshitake
Saitama Medical University International Medical Center, Saitama, Japan
BACKGROUND: In coronary artery bypass grafting(CABG) for hemodialysis(HD) patients, the arteriovenous fistula(AVF) could reduce blood flow from the internal mammary artery(IMA) graft. In this study, we sought to delineate rationale of IMA grafting ipsilateral to AVF by assessing graft flow and patency.
METHODS: Clinical records of 139 HD patients who underwent off-pump CABG including IMA grafting to the left arterial descending (LAD) between April 2007 and December 2018 were retrospectively reviewed. Patients of 103 (74%) were male and 91 (65%) had diabetes. For grafting to LAD, 89 patients had IMA ipsilateral to AVF (group I) and 50 had IMA contralateral to AVF (group C). The stenosis degree was defined as severe (91-100%) and moderate (90% or less), and stenosis location was defined as proximal (LMT or segment 6) and distal (segment 7-8). The results of intraoperative transit-time flowmetry and postoperative angiography were examined. Mean follow-up period was 2.4±2.1 years. Postoperative angiography was performed for 91 (65%) patients.
RESULTS: There was no hospital death in both groups. The mean graft flow (MGF) (ml/min) was 51±30 in the group I and 60±34 in the group C, respectively (p=0.13). The angiographic patency rates were also similar (98% in group I vs. 97% in group C; p=0.73).In the sub-analysis, in patients with moderate stenosis, there no significant difference in MGF (51 ±31 versus 53±27; p=0.74), while in patients with severe stenosis, MGF in the group I was significantly lower than that in the group C (53 ±27 vs. 87±43; p=0.03). In patients with proximal stenosis, there was no difference between both groups (51±24 vs. 60±34; p=0.35). In the Kaplan-Meier analyses, the survival rates at 5 years were 57.6% in the group I and 64.8% in the group C, respectively (log rank p=0.47).
CONCLUSIONS: In revascularization of the LAD, the graft patency rate of the IMA ipsilateral to AVF was not inferior to that of the IMA contralateral to AVF. However, when the LAD has severe stenosis and the abundant graft flow is essentially expected, the IMA contralateral to AVF should be beneficial in terms of sufficient flow capacity.
| N | Ipsilateral IMA | Contralateral IMA | p value | |
| All patients | 139 | 89 | 50 | |
| Flow, ml/min | 51.3±29.9 | 60.2±34.1 | 0.13 | |
| Patency (%) | 55/56 (98) | 34/35 (97) | 0.73 | |
| Severe stenosis | 32 | 21 | 11 | |
| Flow, ml/min | 52.8±26.8 | 86.7±43.3 | 0.03 | |
| Patency (%) | 11/12 (92) | 8/8 (100) | 0.47 | |
| Moderate stenosis | 107 | 68 | 39 | |
| Flow, ml/min | 50.8±30.9 | 52.7±27.4 | 0.74 | |
| Patency (%) | 44/44 (100) | 26/27 (96) | 0.20 |