Mid-term graft patency of right versus left internal mammary artery as arterial conduit usage for left anterior descending artery revascularisation: Insights from a single-centre study of propensity-matched data

Use of the In Situ Right Internal Thoracic Artery as an Alternative Single-Inflow Source

Background

This study was conducted to evaluate whether the in situ right internal thoracic artery (RITA) can be an effective alternative to the left internal thoracic artery (LITA) as a single-inflow source in coronary artery bypass grafting (CABG).

Methods

Between 2006 and 2018, 73 patients underwent CABG with the composite grafting based on the in situ RITA as a single-inflow source (the RITA group). Angiographic patency and clinical outcomes were evaluated. These were compared with results after CABG using the composite grafting based on the in situ LITA (the LITA group) by 1:1 propensity score matching.

Results

Forty-three pairs were extracted by 1:1 propensity score matching. There were no significant intergroup differences in overall patency rates between the RITA and LITA groups at 1 year (92.2% [95/103] and 92.5% [111/120], respectively; P = .90) and 5 years (87.3% [48/55] and 90.4% [85/94], respectively; P = .58). There were no significant differences in the cumulative incidences of reintervention and major adverse cardiac events between the 2 groups (hazard ratio, 2.0 [95% CI, 0.33-11.97] and 1.50 [0.41-5.45], respectively).

Conclusions

Five-year graft patency and long-term clinical outcomes after CABG using the composite grafting based on the in situ RITA were not significantly different from those after CABG using the LITA.

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS)

PREAMBLE

The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

Left Internal Mammary Artery as an Endocrine Organ: Insights Into Graft Biology and Long-term Impact Following Coronary Artery Bypass Grafting

The left internal mammary artery (LIMA) is considered the criterion standard vessel for use in coronary artery bypass grafting. In recent decades, countless studies have documented its superiority over other arterial and venous coronary artery bypass grafting conduits, although the full mechanisms for this superiority remain unknown. A growing body of literature has unveiled the importance of extracellular vesicles known as exosomes in cardiovascular signaling and various pathologic states. In this review, we briefly compare the clinical longevity of the LIMA relative to other conduits, explore the effects of varying grafting techniques on clinical and angiographic outcomes, and provide physiologic insights into graft function on a cellular and molecular level. Finally, we explore exosome signaling as it pertains to atherosclerosis in support of the LIMA as an "endocrine organ."

Coronary artery size as a predictor of Y-graft patency following coronary artery bypass surgery

This study aims to evaluate the association between target vessel size and graft patency in the right IMA-right coronary territory anastomosis.A total of 402 patients who underwent CABG between 2005 and 2016 using the right IMA Y-graft to the posterolateral branch or posterior descending artery were enrolled. Preoperative coronary angiography was utilized to measure the size of the target coronary arteries in the right territory. Follow-up angiography and computed tomography at 6 to 12 months were used to determine graft patency.Thirty patients (7.5%) were found to have occluded graft. Larger target vessel size was associated with lower risk of graft occlusion (OR: 0.18, 95% CI:0.05-0.62, P = .007). The receiver operating characteristic (ROC) curve showed that the cutoff-value of 1.93 mm was found to have the maximum sum of sensitivity and specificity for graft patency (Area under the curve (AUC): 0.65, P = .01). Excluding patients with right coronary artery total occlusion, the discriminative performance of target vessel size became more prominent (AUC: 0.76, P < .01), with same cutoff value.In the setting of bilateral IMA composite grafting, the patency of right IMA to right coronary territory was influenced by the size of the target coronary artery. The influence of target coronary artery size was prominent in non-total occlusion patients. Careful selection of a target anastomosis site is recommended.

Late Outcomes of In Situ Versus Composite Bilateral Internal Thoracic Artery Revascularization

BACKGROUND

We compared 2 configurations for revascularization of the internal thoracic arteries to the anterior and lateral walls. In the "in situ" configuration, an in situ right internal thoracic artery supplies the left anterior descending territory, and an in situ left internal thoracic artery is grafted to the left circumflex territory. In the "composite" configuration, an in situ left internal thoracic artery is grafted to the left anterior descending artery and a free right internal thoracic artery is attached end-to-side to the left internal thoracic artery and supplies the lateral wall.

METHODS

We compared outcomes of all the patients treated in our center by the described strategies during 1996 through 2011.

RESULTS

Of 2951 patients, 1220 underwent composite grafting and 1731 underwent in situ grafting; the median follow-up was 15.1 years (interquartile range, 11.2-18.6 years). Early mortality (2.2% vs 2.0%, P = .787) and other early adverse outcomes did not differ significantly between the groups. Long-term (15-year) survival was marginally significant in favor of the in situ group (53.5% vs 49.5%, P = .05); this difference disappeared after 20 years. Configuration strategy was not a predictor for better 15-year survival in multivariable analysis (hazard ratio, 0.97; 95% confidence interval, 0.85-1.09; P = .568). An additional analysis compared matched groups of 995 patients each who underwent the 2 configuration strategies and found no differences in early outcome or late survival between the groups.

CONCLUSIONS

This study demonstrated the safety and effectiveness of 2 strategies for bilateral internal thoracic artery revascularization to the left side, with comparable early outcomes and long-term survival.

Use of the right internal mammary artery and the great saphenous vein for left anterior descending artery revascularization in patients whose left internal mammal artery cannot be used: a study based on transit-time flow measurement

Background

Owing to the high patency, the use of the left internal mammary artery (LIMA) for left anterior descending artery (LAD) grafting has been a cornerstone of coronary artery bypass grafting surgery (CABG). However, for some patients whose LIMA cannot be used, surgeons have to choose other conduit materials to revascularize the LAD. The purpose of this study was to explore the differences in different conduit materials used for LAD in terms of parameters measured by transit-time flow measurement (TTFM) and the early graft patency detected by computed tomography angiography.

Methods

We retrospectively collected the data of 410 patients who underwent isolated primary OPCAB with intraoperative TTFM data. According to the strategy of the LAD revascularization, 410 patients were assigned to three groups: a left internal mammal artery (LIMA) group (n = 333), a right IMA (RIMA) group (n = 34) and a great saphenous vein (SVG) group (n = 43). The baseline and perioperative blood parameters were compared for the three groups, as well as the early graft patency rates.

Results

Compared with the LIMA-LAD group, the SVG-LAD group had a significantly higher mean graft flow volume (MGF) (37.15 ± 23.29 vs 29.71 ± 20.94 ml/min, P = 0.036), however, had a lower value of pulse index (PI) (2.07 ± 0.62 vs 2.65 ± 1.01, P<0.001). There was no significant difference between the two groups in terms of DF (P>0.05). Compared with the RIMA-LAD group, the SVG-LAD group just had a lower value of PI (2.07 ± 0.62 vs 2.56 ± 0.96, P = 0.029). However, there was no significant difference between the two groups in terms of MGF and DF (P>0.05). Compared with the LIMA-LAD group, the RIMA-LAD group had a slightly lower value of DF (70.76 ± 11.87 vs 74.06 ± 7.09, P = 0.018), while there was no difference in terms of MGF and PI between the two groups (P>0.05). The patency rate of the LIMA-LAD group was 98.72% (309/313), that of RIMA-LAD group was 97.06% (33/34), and that of SVG-LAD group was 100%. There was no difference among the three groups in patency rate (P = 0.405).

Conclusions

SVG-LAD has a higher intraoperative MGF and a lower value of the PI than both LIMA-LAD and RIMA-LAD. RIMA has a higher preoperative blood flow and a lower value of the PI than LIMA; however, there were no significant difference between RIMA grafted to LAD and LIMA grafted to LAD in terms of MGF, PI and DF. In situ skeletonized RIMA did not increase blood flow compared to pedicled LIMA.

Internal mammary artery: the primary conduit for surgical revascularization

Internal mammary artery, by far, is the gold standard and first conduit for surgical revascularization especially when it comes to bypassing a lesion in the left anterior descending coronary artery. Several factors behind using this artery have been established, including but not limited to, the anatomical location, the course and flow, the elastic nature of the artery as well as the physiological characteristics that make this conduit to yield excellent long-term patency rates. This review aims to thoroughly examine current literature and establish the facts behind using this conduit in our daily surgical revascularization practice.

Left anterior descending artery revascularization with the right internal thoracic artery T-graft: the 'reverse composite' configuration

OBJECTIVES

The use of bilateral internal thoracic artery graft for myocardial revascularization has improved the long-term survival and decreased the rate of repeat interventions in patients. A key technical factor for complete arterial revascularization is sufficient length of the internal thoracic artery (ITA) graft. The purpose of this study was to compare early and long-term outcomes of 'standard composite' grafting and 'reverse composite' grafting. In the former, the left ITA (LITA) is connected to the left anterior descending artery, and the right ITA is connected end-to-side to the LITA for revascularization of the left circumflex artery. In 'reverse composite' grafting, the LITA is connected to the left circumflex artery, and the right ITA is connected end-to-side to the LITA, for revascularization of the left anterior descending artery.

METHODS

We compared the outcomes of 1365 patients who underwent coronary artery bypass grafting in Tel-Aviv Sourasky Medical Centre, using bilateral ITA as standard composite versus 'reverse composite' grafts, between January 1996 and December 2011. A propensity score matching analysis compared 132 pairs of patients who underwent bilateral ITA by the 2 modes.

RESULTS

Twelve hundred and thirty patients underwent standard 'composite' grafts and 135 underwent 'reverse composite' grafts. Early mortality and early adverse effects did not differ significantly between the groups. After matching, the difference in late mortality between the groups was not statistically significant.

CONCLUSIONS

This study suggests that revascularization of the left anterior descending with the right ITA, arising from an in situ LITA, is safe and provides early outcomes and long-term survival that are not significantly different from those of the standard composite grafting technique. However, there was evidence of better survival in the standard composite group.