Complete Revascularization of the Three-Vessel Territories Using a Left Internal Thoracic Artery Composite Graft

Competitive Flow of Terminal Anastomosis to Right Coronary Territory in "Y" Coronary Artery Bypass

BACKGROUND

We evaluated the prevalence and outcomes of competitive flow in the terminal right coronary artery (RCA) graft after coronary artery bypass grafting (CABG) with left internal thoracic artery-based Y-composite grafting at 1 year after CABG.

METHODS

We enrolled 642 patients who underwent Y-composite graft-based off-pump CABG with in situ left internal thoracic artery between 2014 and 2022. All patients underwent early postoperative angiography, and 1-year postoperative angiography was performed in 81.2% (522/642) of patients.

RESULTS

The early occlusion rate of distal anastomoses with Y-composite graft was 2.1%. Competitive flow was observed in 69 of 642 anastomoses (10.7%). Multivariate analysis showed that the maximal degree of target vessel stenosis (odds ratio [OR], 0.909; 95% CI, 0.886-0.931; P < .001), maximal degree of non-terminal target vessel in Y-arm grafts (OR, 1.103; 95% CI, 1.047-1.172; P < .001), and diabetes mellitus (OR, 0.535; 95% CI, 0.303-0.934; P = .029) were factors associated with competitive flow to the RCA territory. The optimal cutoff value for the degree of terminal target vessel stenosis predicting competitive flow to the RCA territory was 92.5%. The 1-year graft failure rate of anastomoses with competitive flow of the terminal anastomosis was 30.9% (17/55). The presence of competitive flow on early angiography was the only factor associated with graft occlusion of the terminal anastomosis at 1 year (OR, 2.339; 95% CI, 1.165-4.481; P = .013).

CONCLUSIONS

For terminal anastomosis to the RCA territory in Y-composite graft-based CABG, the presence of competitive flow on early angiography was associated with graft occlusion of the terminal anastomosis at 1 year. Notably, 30.9% of these grafts demonstrated failure on 1-year follow-up angiography.

Graft Patency of No-Touch Saphenous Veins Used as Aortocoronary Bypass Grafts

Background

This study evaluated the early, 1-year, and 3-year graft patency rates and mid-term clinical outcomes after no-touch saphenous veins (NT-SVs) were used as aortocoronary grafts in coronary artery bypass grafting (CABG).

Methods

In total, 101 patients who underwent CABG using NT-SVs as aortocoronary grafts were included. The 2 most common indications for performing aortocoronary grafting with NT-SVs were unavailability of the left internal thoracic artery (n=36) and moderate lesions where flow competition was expected (n=27). Early (median, 1 day; interquartile range [IQR], 1-2 days), 1-year (median, 13 months; IQR, 11-16 months), and 3-year (median, 34 months; IQR, 27-41 months) graft angiography was performed in 98 (97.0%), 84 (83.2%), and 40 patients (39.6%), respectively. The median follow-up duration was 43 months (IQR, 13-76 months). Overall survival rates and the cumulative incidence of major adverse cardiac events were evaluated.

Results

The operative mortality rate was 2% (2 of 101 patients). Early postoperative patency rates for overall and aortocoronary NT-SV grafts were 98.2% (223 of 227 distal anastomoses) and 98.2% (164 of 167), respectively. The 1- and 3-year patency rates for aortocoronary SV grafts were 94.9% (131 of 138) and 90.6% (58 of 64), respectively. The overall survival rates at 5 and 10 years were 81.7% and 59%, respectively. The cumulative incidence of major adverse cardiac events at 5 and 10 postoperative years was 20.7% and 39%, respectively.

Conclusion

The feasibility of using NT-SVs as aortocoronary grafts in CABG was shown in this study, based on the graft patency rates up to 3 years and the mid-term clinical outcomes.

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.

Competitive Flow in Vein Composite Grafts Based on the Left Internal Thoracic Artery: Early and 1-Year Angiographic Analyses

We assessed the incidence of competitive flow with early postoperative angiograms in patients who received a "no-touch" saphenous vein (NT SV) composite graft and reexamined the status of competitive flow at 1-year. Early postoperative angiograms were performed in 806 patients who underwent myocardial revascularization using a NT SV Y-composite graft based on the in situ left internal thoracic artery (LITA). Competitive conduit flow was observed in 102 distal anastomoses (102 of 3039 [3.4%] anastomoses) of 94 patients (94 of 806 [11.7%]; NT SV competitive flow in 74 and LITA competitive flow in 20). Of the 94 patients, 63 patients (50 with NT SV competition and 13 with LITA competition) were re-evaluated with 1-year postoperative angiograms. Fifty-six competitive NT SV conduits in 50 patients were reevaluated at 1-year postoperatively: 44 (78.6%) early competitive anastomoses had become patent and 12 (21.4%) were occluded. NT SV with pedicle tissue showed a higher tendency of being perfectly patent at 1-year postoperatively than NT SV without pedicle tissue (17 of 40 [42.5%] vs 2 of 16 [12.5%]; P = 0.007). Thirteen competitive LITA conduit anastomoses in 13 patients were reevaluated 1-year postoperatively: 9 (69.2%) early competitive anastomoses had become patent and 4 (30.8%) were occluded. Competitive flow was shown on early postoperative angiograms in 3.4% of distal anastomoses in patients who received NT SV Y-composite grafts. Approximately 80% of the competitive NT SV conduits were patent 1-year postoperatively, and perfect patency rates were higher in patients who had received NT SV with pedicle tissue than in patients who had received NT SV without pedicle tissue.

Bilateral internal thoracic artery grafting: propensity analysis of the left internal thoracic artery versus the right internal thoracic artery as a bypass graft to the left anterior descending artery

OBJECTIVES

To compare different configurations of the bilateral internal thoracic arteries for the left coronary system and examine early and late outcomes, including mid-term graft patency.

METHODS

We reviewed 877 patients who underwent primary isolated coronary artery bypass grafting using in situ bilateral internal thoracic arteries [in situ right internal thoracic artery (RITA)-to-left anterior descending artery (LAD) grafting, n = 683; in situ left internal thoracic artery (LITA)-to-LAD grafting, n = 194]. We compared mid-term patency between the grafts. Propensity score matching was performed to investigate early and long-term outcomes.

RESULTS

The 2-year patency rate for RITA-to-LAD and LITA-to-LAD grafts were similar. Multivariate analysis revealed that RITA-to-non-LAD anastomosis (P = 0.029), postoperative length of stay (P = 0.003) and chronic obstructive pulmonary disease (P = 0.005) were associated with graft failure. After statistical adjustment, 176 propensity-matched pairs were available for comparison. RITA-to-LAD grafting enabled a more distal anastomosis. Kaplan-Meier analysis revealed that the incidences of death, repeat revascularization and myocardial infarction were significantly higher in the LITA-to-LAD group among both the unmatched and matched samples (P = 0.045 and 0.029, respectively).

CONCLUSIONS

The mid-term patency and outcomes of RITA-to-LAD grafting are good and reduces future cardiac event, in contrast to LITA-to-LAD grafting.

Saphenous vein as a composite graft from the internal thoracic artery

The saphenous vein (SV) has been used as an aortocoronary bypass graft for coronary artery bypass grafting (CABG) for the past 50 years. However, CABG using the aortocoronary SV has shown disadvantages of lower long-term graft patency rates and subsequently worse clinical outcomes, compared with CABG using the internal thoracic artery (ITA). The advantages of CABG using the ITA prompted interest in total arterial revascularization, using the bilateral ITAs and other arterial conduits as composite graft configurations in patients exhibiting multi-vessel disease. Total arterial revascularization using a Y- or T-composite graft based on the in situ ITA increases the length of the arterial graft and allows the extensive use of arterial conduits to revascularize both the left and right coronary territories. Further, it has demonstrated favorable outcomes in terms of angiographic patency rates, myocardial perfusion and thickening by single photon emission computed tomography, and long-term clinical outcomes. However, previous studies describing the use of the SV conduit as a composite graft have produced conflicting results. In this article, a recent surgical strategy of using the SV as part of a composite graft based on the in situ left ITA will be discussed.

Bilateral internal thoracic arteries: what is the State of the ART?

PURPOSE OF REVIEW

To provide a broad overview of the current state of knowledge of coronary artery bypass grafting with bilateral internal thoracic artery (BITA).

RECENT FINDINGS

There exists a large body of literature from mostly observational studies supporting the use of BITA in patients undergoing coronary artery bypass grafting but selection bias is a major issue with nonrandomized data. The precise method of BITA use does not appear to impact graft patency nor clinical outcomes - in other words, BITA in any configuration appears to be protective. The major downside is the increased risk of sternal complications, which can be mitigated with sternal-sparring adjuncts. The 5-year interim results of the landmark Arterial Revascularization Trial comparing BITA versus single internal thoracic artery did not show a clinical benefit for BITA but the end-of-trial results are pending. Despite wide guideline support for BITA use, uptake in the surgical community remains low and this is likely because of technical and institutional barriers.

SUMMARY

The published literature thus far supports surgical revascularization with BITA and we eagerly await the 10-year Arterial Revascularization Trial results. The general consensus is that a greater proportion of surgical revascularization should be performed using BITA.

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.

Association between postoperative bulla neogenesis at the staple line and resected lung weight for primary spontaneous pneumothorax: a retrospective study using the inverse-probability of treatment weighted method in patients grouped according to age

BACKGROUND

Bullectomy using autosutures is the standard procedure in patients with primary spontaneous pneumothorax (PSP). However, postoperative bulla neogenesis (POBN) along the staple line is relatively common and promotes PSP recurrence. We have previously reported the relationship between POBN and resected lung weight (LW). However, recently published data indicate that young patients with PSP have a high postoperative recurrence rate. Therefore, we evaluated the relationship between POBN and LW in PSP patients, subdivided according to age.

METHODS

Between February 2011 and April 2016, 96 lung-resection sites in 67 patients who underwent bullectomy were evaluated. Patients were subdivided into two groups by age: Y group (<25 years, 56 sites) and O group (≥25 years, 40 sites). We used the inverse-probability of treatment weighted (IPTW) method to adjust for the heterogeneity in their backgrounds. POBN was diagnosed by computed tomography.

RESULTS

Cox regression analysis for the O group indicated that LW ≥3.0 g was a significant risk factor for POBN (P=0.049). For the Y group, no association between lung weight and POBN was observed.

CONCLUSIONS

A LW ≥3.0 g is a significant risk factor for POBN in individuals aged ≥25 years.

A systematic review and meta-analysis of in situ versus composite bilateral internal thoracic artery grafting

OBJECTIVES

This meta-analysis examines whether there is any advantage of coronary artery bypass graft with bilateral internal thoracic artery (BITA) as an in situ versus composite graft.

METHODS

We searched MEDLINE and EMBASE Databases from 1996 to 2016 for studies that compared coronary artery bypass graft with BITA as in situ versus composite graft. Data were extracted by 2 independent investigators and meta-analyzed with the use of random effects.

RESULTS

Two randomized controlled trials (RCTs; n = 705), 2 matched (n = 1688), and 4 unadjusted observational studies (n = 3517) met inclusion criteria. Composite grafting trended towards greater distal anastomoses (+0.22, 95% confidence interval, -0.01 to +0.45 anastomoses/patient; P = .06 [4 unadjusted observational studies]) and greater distal anastomoses using an internal thoracic artery (+0.80, 95% confidence interval, 0.41-1.18 anastomoses/patient; P < .001 [1 RCT]). There were no differences in perioperative or longer-term composite cardiovascular outcomes comparing in situ versus composite BITA or individual outcomes of mortality, repeat revascularization, myocardial infarction, and cardiovascular mortality. Pooled results differed by study type with pooled results from lower-risk-of-bias RCTs typically showing increases in events rates, and pooled results from higher-risk-of-bias unadjusted observational studies typically showing decreases in event rates of in situ versus composite BITA. Post hoc subgroup analysis suggested possible improvements in all-cause mortality and revascularization for in situ BITA in studies with short-term (<5 years) versus longer-term follow-up, regardless of study type.

CONCLUSIONS

Our meta-analysis found that use of BITA as a composite graft configuration facilitated greater internal thoracic artery revascularization but both grafting strategies offer similar clinical outcomes. Our study supports the use of in situ and composite BITA for select patients but high-quality, long-term prospective trials are needed.