Bilateral Internal Thoracic Grafting Research Articles

Worldwide Trends in Multi-arterial Coronary Artery Bypass Grafting Surgery 2004-2014: A Tale of 2 Continents

Recent evidence shows that multi-arterial coronary artery bypass grafting (MABG) based on bilateral internal thoracic (BITA) or left internal thoracic (LITA) and radial artery (RA) improves long-term outcomes compared with single arterial coronary artery bypass grafting (SABG) (LITA + saphenous vein graft). How this evidence affected the worldwide use of MABG, if at all, is not well defined. Accordingly, we report 10-year temporal trends of MABG utilization from 2 continents. A study population of 1,683,434 non-emergent, primary, isolated LITA-based coronary artery bypass grafting (CABG) (≥2 grafts) patients was derived from the Society of Thoracic Surgeons (STS) (1,307,528 (79.5%) of 1,644,388 isolated CABG; total 1179 centers) and the Australia New Zealand Cardiothoracic (ANZ) Databases (34,213 (87%) of 39,046 isolated CABG; 24 centers) between 2004 and 2014. Patients were excluded based on the following: (1) no LITA, (2) if arterial grafts were other than RA or ITA, or (3) if grafting data were missing. The 3 MABG groups were LITA + RA, BITA, and BITA + RA, each with or without supplemental vein grafts. Grafting trends and their associated patient demographics were analyzed. SABG (89.3% STS, 51.4% ANZ) was the most common grafting strategy. MABG was most frequently accomplished by LITA + RA: (STS: 6.1%; ANZ: 42.6%), followed by BITA: (STS: 4.1%; ANZ: 4.3%), while ≥3 (BITA + RA) was rare in the STS (0.5%), but more common in ANZ (5.9%). In the STS, between 2004 and 2014, SABG rates systematically increased from 85.2% to 91.7%, BITA grafting was essentially unchanged from 3.6% to 4.3%, while RA use decreased systematically from 10.5% to 3.7%. In the ANZ, SABG rates increased from 17.3% to 51.4%, BITA grafting decreased from 6.3% to 3.6%, while RA grafting decreased from 65.8% to 39.0%. Compared with SABG patients, BITA patients were younger (STS: median age 59 vs 66, P < 0.001; ANZ: mean age 62 vs 68, P < 0.001), predominately male (STS: 84% vs 73%, P < 0.001; ANZ: 86% vs 79%, P < 0.001), less obese (body mass index >30 kg/m2) in STS (37% vs 42%, P < 0.001), more obese in ANZ (33% vs 32%, P = 0.001), and less diabetic (STS: 26% vs 43%, P < 0.001; ANZ: 25% vs 37%, P < 0.001), whereas RA patients were intermediate in age (STS: 61; ANZ: 65), in male sex (STS: 82%; ANZ: 81%), in the prevalence of diabetes (STS: 40%; ANZ: 34%), and were most obese (STS: 47%; ANZ: 34%). A decade-long analysis of STS data reveals a counterintuitive decline in the use (driven by decreasing RA use) of MABG: a potentially superior grafting strategy compared with SABG. In contra distinction, the smaller but growing ANZ data document a distinctly different CABG practice pattern, with a higher MABG utilization rate, but a similarly declining RA use. The reasons for these practice patterns and declining MABG are likely diverse and require further assessment.

Off-pump Bilateral Internal Thoracic Artery Grafting

The long-term benefit of bilateral internal thoracic grafts (BITA) is well established. BITA grafting is often avoided in diabetic, female, obese, elderly and other high-risk patients because of concerns for deep sternal wound infection. The objective of this study is to analyse early results of our BITA grafting and to establish the safety of BITA use in all patients. All cases of isolated consecutive unselected CABG were included in this retrospective study. BITA were used in-situ - one was used to graft left anterior descending artery and the other was used as inflow for a composite graft with radial artery. Dual inflow using in situ BITA grafting allows easy bailout by using an additional vein graft. BITA was used in 574 patients out of 602 (95.35%). Incidence of early death was 1.33% (8/602), stroke 0.5% (3/602), reoperation for bleeding 0.17% (1/602). Deep sternal wound infection was not seen in any patient but nine patients (1.5%) had superficial wound infection which healed with dressing. We have used BITA in 95% of our unselected, consecutive off-pump CABG patients without any major wound complications. Our limited experience has shown off-pump CABG using BITA grafting can be safely adopted routinely with excellent early result.

Off-Pump Coronary Artery Bypass Grafting With Skeletonized Bilateral Internal Thoracic Arteries in Insulin-Dependent Diabetics

We evaluated the effects of coronary artery bypass with off-pump skeletonized bilateral internal thoracic artery grafting in patients with insulin-dependent diabetes. One hundred eighty-five consecutive patients with insulin-dependent diabetes who underwent isolated coronary artery bypass grafting with bilateral internal thoracic grafts were retrospectively compared according to surgical technique, ie, off-pump grafting with skeletonized internal thoracic artery (n = 162) or on-pump grafting with pedicled internal thoracic artery (n = 23). The on-pump group was younger (62.3 +/- 9.2 versus 69.9 +/- 8.5 years; p = 0.02) and had fewer distal anastomoses (3.5 +/- 1.0 versus 4.0 +/- 1.1; p = 0.02) than the off-pump group. No 30-day mortality occurred in either group. The incidence of deep sternal infection was significantly lower in the off-pump group than in the on-pump group (0.6% versus 13.0%; p = 0.01). The early angiographic results did not differ between the two groups. The median duration of follow-up was 3.4 years (range, 0.1 to 9.9 years). Rates of survival, freedom from cardiac mortality, and freedom from cardiac-related events (including cardiac-related death, myocardial infarction, percutaneous coronary intervention, repeat coronary artery bypass grafting, and congestive heart failure) did not differ between the two groups. Dialysis, peripheral vascular disease, ejection fraction less than 0.40, and age were independent risk factors of late death. Overall, our results support the surgical management of coronary artery bypass grafting in insulin-dependent diabetics using off-pump skeletonized bilateral internal thoracic artery grafting.

Topical Application of Bacitracin Ointment Is Associated with Decreased Risk of Mediastinitis after Median Sternotomy

The diagnosis of mediastinitis after open-heart surgery is infrequent but dreaded as it carries a high morbidity and mortality. The purpose of this study was to investigate the impact that topical antibacterials would have on the postoperative mediastinitis rate. Data were collected from 2455 consecutive patients who underwent sternotomy and cardiopulmonary bypass for both valvar and ischemic heart disease. Prior to 1999, patients (n = 1036) underwent surgery with standard perioperative intravenous antibiotics but no application of bacitracin. After 1999, patients (n = 1419) underwent surgery with intravenous antibiotics and application of bacitracin ointment to the sternotomy incision after closure. Cases of mediastinitis occurred in 12 patients (1.2%) not treated with bacitracin, which required re-exploration, sternectomy, and soft tissue closure of the mediastinum. Alternatively, 3 patients (0.2%) in the group treated with bacitracin developed mediastinitis (P < .01). Therefore, the use of topical antibacterials was associated with a 6-fold reduction in the risk of mediastinitis after cardiac surgery. This significant difference in the infection rate was observed even though the percentage of patients with risk factors for mediastinitis was equal to greater than the group not treated with bacitracin. Non-bacitracin versus bacitracin: diabetics, 298 versus 484; emergency operations, 24 versus 50; bilateral internal thoracic grafts, 28 versus 29; and obesity (body mass index >30), 294 versus 396. The use of topical antibacterials is associated with a decrease in the risk of mediastinitis after cardiac surgery.

Drug-Eluting Stents Versus Bilateral Internal Thoracic Grafting for Multivessel Coronary Disease

Reduction of restenosis and reinterventions was recently reported with percutaneous interventions (PCI), including drug-eluting stents (Cypher; Cordis, Miami Lakes, FL). This study compares results of multivessel Cypher stenting with those of bilateral internal thoracic artery (BITA) grafting. From January 2002 to June 2004, 768 consecutive patients underwent multivessel myocardial revascularization; 138 by PCI including Cyphers and 630 by BITA. After matching for age, sex, ejection fraction, extent of coronary disease, and congestive heart failure, two groups (113 patients each) were used to compare the two revascularization modalities. Both groups were similar; however, left main and intraaortic balloon were more prevalent in the BITA group. The number of coronary vessels treated per patient was higher in the BITA group (2.87 vs 2.22, p < 0.001). Follow-up ranged between 6 and 34 months. Thirty-day mortality was 0.9% in the BITA and zero in the PCI group (p = 0.32). There were no late deaths in the BITA and three (2.7%) in the Cypher group (p = 0.08). Angina returned in 28.3% of the Cypher and 12.4% of the BITA group, p = 0.003. A Cox proportional hazard model revealed assignment to the Cypher group to be the only predictor of angina recurrence (odds ratio 2.78, 95% confidence interval 1.46-2.56). There were 16 (14.2%) reinterventions in the Cypher group compared with six (5.3%) in the BITA group. One-year reintervention-free survival (Kaplan-Meier) of the BITA was 96% compared with 86.6% in the Cypher group (p = 0.005, log-rank test). Despite improved results of PCI with Cyphers, midterm clinical outcome of multivessel patients treated with BITA is still better.

Comparison of bilateral thoracic artery grafting with percutaneous coronary interventions in diabetic patients

Background This study compares the outcome of percutaneous coronary interventions (PCI) with bilateral internal thoracic grafting (BITA) in diabetic patients. Methods From May 1996 to December 1999, 802 consecutive diabetic patients underwent myocardial revascularization: 363 by PCI and 439 by BITA. The two groups were similar; however, left main disease (28% versus 3.3%), ejection fraction less than 0.35 (14.5% versus 5.5%), and chronic obstructive lung disease (8.4% versus 3%) were more prevalent in the BITA group, and prior percutaneous transluminal coronary angioplasty, in the PCI group (16.8% versus 10.5%). Results The number of coronary vessels treated per patient was higher in the BITA group (3.4 versus 1.2; p < 0.001). Thirty-day mortality was similar: 3.4% in the BITA group and 2.8% in the PCI group. Late follow-up (3 to 6.5 years) showed decreased return of angina (11% versus 64%; p < 0.001), fewer reinterventions (2.7% versus 55%; p < 0.001), and increased cardiovascular event-free survival (80% versus 30%; p < 0.001) in the BITA group. Six-year survival of BITA and PCI patients was 85.5% and 81.2%, respectively (not significant). However, survival of the subgroups of patients with left main or three-vessel coronary artery disease was significantly better with BITA (86% versus 76%; p = 0.003). Conclusions Despite higher risk profile of diabetic patients treated surgically by BITA, their late outcome is better than that of patients treated by PCI. The results of this study support referring diabetics with single-vessel or double-vessel disease to PCI and those with three-vessel and left main coronary artery disease to surgery.