Selection of Dialysis Patients for Bilateral Internal Thoracic Artery Grafts

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

BACKGROUND

In 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.

METHOD

The 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.

RESULTS

An 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).

CONCLUSIONS

In 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.

Influence of Ipsilateral Graft Inflow to Arteriovenous Fistula for Hemodialysis in Coronary Bypass Surgery

In coronary artery bypass grafting (CABG) for patients on hemodialysis, there has been concern about “coronary steal”. This study aims to evaluate the influence of using an in situ internal thoracic artery (ITA) ipsilateral to a preexisting arteriovenous fistula (AVF) in dialysis-dependent patients undergoing CABG. Between 2004 and 2018, dialysis-dependent patients with AVFs who underwent CABG were enrolled. According to the locational relationship of AVFs and in situ ITA grafts, the patients were divided into the ipsilateral group (n = 22) and the contralateral group (n = 21). Inverse probability weighting analysis was used to estimate and compare the late clinical outcomes. The late cardiac-related adverse events were not significantly different between the two groups: “major adverse cardiovascular and cerebrovascular events (MACCE)” (p = 0.090), “composite outcome of recurrent angina and coronary re-intervention” (p = 0.600). The in situ ITA graft of CABG on the ipsilateral side to AVF was not a significant risk factor for MACCE or the composite outcome of recurrent angina and coronary re-intervention. There was no statistically significant difference in the graft patency between the groups. Therefore, it might not be necessary to avoid using an in situ ITA on the ipsilateral side of an upper-arm AVF for optimal coronary artery bypass grafting in dialysis-dependent patients.

The incidence and risk factors of coronary steal after ipsilateral AVF in patients with a coronary artery bypass graft

Objective

Ipsilateral arteriovenous fistula (AVF) may cause symptoms of coronary steal in patients who had undergone coronary artery bypass graft (CABG) using internal thoracic artery. The purpose of this study was to evaluate the adverse effects of ipsilateral AVF to CABG, including the incidence of coronary steal, and to analyze the risk factors for coronary steal.

Methods

Between 2000 and 2013, a total of 25 patients undergoing hemodialysis via upper extremity AVF, ipsilateral to the preexisting CABG, were reviewed retrospectively. Clinical assessment related to coronary steal, echocardiography before AVF, and coronary angiography after symptoms were assessed. The definition of coronary steal was the new development of one or more of the following symptoms within 12 weeks after AVF creation: chest pain, chest discomfort, and dyspnea.

Results

Three patients were clinically diagnosed as coronary steal. Left ventricular ejection fraction (LVEF) was statistically lower in coronary steal group compared to no-steal group (41.7% vs. 50.9%; p = 0.036). Patients with coronary steal were older at the age of CABG surgery and showed a higher incidence of regional wall motion abnormality.

Conclusions

Coronary steal after ipsilateral AVF creation in patients with CABG using in situ internal thoracic artery (ITA) developed in 12%, which can be related to low LVEF. In patients with CABG requiring AVF for hemodialysis, the ipsilateral fistula to the grafted ITA should be carefully selected and performed.