Single Internal Mammary Artery Research Articles

Predominant Use of Bilateral Internal Mammary Arteries in Off-Pump Coronary Artery Bypass Surgery

Bilateral internal mammary artery (BIMA) in coronary artery bypass grafting (CABG) has been shown to provide long-term clinical benefits over single internal mammary artery (SIMA) grafting. Nevertheless, the perceived technical complexity of the procedure and concerns about potential early postoperative complications, particularly sternal wound infections have led to a utilization rate of BIMA grafting of less than 5% in the United States. We systematically compared early (30-day) post-operative outcomes between the BIMA and SIMA cohorts in patients with similar baseline characteristics. A retrospective single center study was conducted on matched patients, using stabilized inverse probability treatment weighting to mitigate bias between the two study cohorts. From 546 off-pump CABG patients initially identified, we examined 328 BIMA and 213 SIMA grafts from the matched samples. Despite utilizing 60.4% BIMA grafts, we observed similar rates of 30-day overall and cardiac mortality between the BIMA and SIMA groups. Rates of 30-day postoperative complications, including superficial and deep sternal wound infections, stroke, sepsis, acute kidney injury, and cardiac arrest, were similar between the two groups. Rates of 30-day overall and cardiac readmission were also similar. Additionally, median length of hospital stays, intensive care unit stay, and ventilation times were similar between the two groups. In conclusion, our data suggest that a BIMA utilization rate of 60.4% in off-pump CABG procedure is achievable without causing any significant increment in early post-operative complications, including deep sternal wound infection.

Long Term Survival Benefits of Different Conduits Used in Coronary Artery Bypass Graft Surgery- A Single Institutional Practice Over 20 Years.

This study determined hazard factors and long-term survival rate of total arterial coronary artery bypass graft surgery over 20 years in an extensively large, population-based cohort. A total of 2979 patients who underwent isolated CABG from April 1999 to March 2020 were studied in 4 groups- Group-A (bilateral internal mammary artery ± radial artery), Group-B (single internal mammary artery + radial artery ± saphenous vein), Group-C (single internal mammary artery ± saphenous vein; no radial artery), and Group-D (radial artery ± saphenous vein; no internal mammary artery). The study endpoints analysed the correlation between the number and types of grafts with the survival time following isolated CABG surgery. The total arterial revascularization (Group A) group had an admirable mean long-term survival of ~19 years, compared to 18.6 years (Group B), 15.86 years (Group C), and 10.99 years (Group D). A Kaplan-Meier curve demonstrated confidence interval (CI) for study groups- (95% CI 18.33-19.94), (95% CI 18.14-19.06), (95% CI 15.40-16.32), and (95% CI 9.61-12.38) in Group A, B, C, D respectively. In the Holm-Sidak method analysis, significant associations existed between the number of arterial grafts and the long-term outcome. A statistically significant (P≤0.05) long-term survival advantage for arterial grafting was demonstrated, especially total arterial revascularisation over all other combinations except single internal mammary artery + radial artery grafting. In this series, over 20 years, total arterial CABG use has excellent long-term survival, achieving complete myocardial revascularisation. There is no significant difference between the BIMA group and SIMA with radial artery. However, there is a reduced survival with decreased use of arterial conduits.

Why Are We Weighting? Understanding the Estimates From Propensity Score Weighting and Matching Methods.

Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. We sought to explain the treatment effect estimates derived from different propensity score methods. We performed a retrospective analysis of long-term mortality after single internal mammary artery versus bilateral internal mammary artery (BIMA) conduit in 47 984 index isolated coronary artery bypass grafting procedures from 1992 to 2014 in the Northern New England Cardiovascular Disease Study Group registry using multivariable Cox regression, 1:1 propensity score matching, inverse probability weighting (IPW) among the treated, and IPW among the overall population treatment estimates. The mean duration of follow-up was 13.2 (interquartile range, 7.4-17.7) years. In multivariable Cox regression, the adjusted hazard ratio for mortality was 0.83 (95% CI, 0.75-0.92) in patients receiving BIMA compared with a single internal mammary artery. The 1:1 propensity matched (hazard ratio, 0.79 [95% CI, 0.69-0.91]) and IPW among the treated (hazard ratio, 0.83 [95% CI, 0.75-0.92]) estimates showed a protective treatment effect of BIMA use on mortality. However, the IPW estimate of treatment effect for the overall population showed an increased risk of mortality after BIMA that was not statistically significant (hazard ratio, 1.08 [95% CI, 0.94-1.24]). While the multivariable Cox regression, 1:1 propensity matching, and IPW treatment effect in the treated estimates demonstrate that BIMA was associated with a statistically significantly decreased risk of mortality, the IPW treatment effect in the average study population showed an increased risk of mortality associated with BIMA that was not statistically significant. This is attributed to the different populations (weighted to look like the overall study population versus treated group) represented by the 2 IPW approaches. Determining how the study population is balanced is a large driver of the treatment effect. Ultimately, the treatment effect estimate desired should drive the choice of the propensity score method.

Bilateral versus single internal mammary artery in diabetic patients: systematic review and meta-analysis.

Data on bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) on diabetics were analyzed; This is the only meta-analysis, the last 7 years. Medline through PubMed/EMBASE/CINHAL and the Cochrane Central Register of Controlled Trials; 179 articles were studied; 19 studies deemed suitable and were included in the analysis. The mortality was 2.41% for BIMA versus 1.71% for SIMA (odds ratio [OR] = 0.95; 95% confidence interval [CI]: 0.74-1.22). Postoperative reopening for bleeding was higher at 3.75% for BIMA versus 2.91% for SIMA (OR = 1.49; 95% CI: 1.15-1.93). The incidence of MI was 0.87% for BIMA versus 0.83% for SIMA (OR = 0.73; 95% CI: 0.37-1.44). Deep sternal wound infection was 3.02% for BIMA and 1.95% for SIMA (OR = 1.57; 95% CI: 1.26-1.95). When skeletonized, the incidence of DSWI was 2.5% for BIMA versus 2.41% for SIMA. There was a significant difference at 5-year survival favoring the BIMA, 85.15% BIMA versus 80.77% SIMA (OR = 1.79; 95% CI: 1.60-2.01). The 10-year overall survival was 74.04% BIMA versus 61.57% SIMA (OR = 1.79; 95% CI: 1.61-1.98). The 15-year survival was 47.08% for BIMA versus 37.06% for SIMA (OR = 1.69; 95% CI: 1.52-1.88). Postoperative bleeding was higher in BIMA group. Bilateral internal mammary artery in diabetic patients should be carried out in a skeletonize fashion, to reduce DSWI. There is a survival benefit of using BIMA in diabetics within 5 years of surgery; it remains significant up to 15 years.

Sternal wound infections following internal mammary artery grafts for a coronary bypass: A meta-analysis.

The meta-analysis aims to evaluate and compare the sternal wound infections following internal mammary artery grafts for a coronary bypass. Examinations comparing bilateral internal mammary artery to single internal mammary artery for coronary artery bypass grafting were among the meta-analyses from various languages that met the inclusion criteria. Using dichotomous random- or fixed-effect models, the results of these investigations were examined, and the Odd Ratio (OR) with 95% confidence intervals (CIs) was computed. A total of 31 examinations from 2001 to 2023 were recruited for the current analysis including 181 503 personals with coronary artery bypass grafting. Bilateral internal mammary artery had significantly higher sternal wound infection (OR, 1.51; 95% CI, 1.37-1.68, p < 0.001), superficial sternal wound infection (OR, 1.72; 95% CI, 1.16-2.56, p = 0.007), deep sternal wound infection (OR, 1.62; 95% CI, 1.41-1.86, p < 0.001), sternal wound infection in diabetics (OR, 1.48; 95% CI, 1.16-1.90, p = 0.002), sternal wound infection in elderly (OR, 1.38; 95% CI, 1.22-1.57, p < 0.001), sternal wound infection in pedicled preparation (OR, 1.70; 95% CI, 1.30-2.23, p < 0.001) and sternal wound infection in skeletonized preparation (OR, 1.40; 95% CI, 1.09-1.81, p = 0.009) compared to single internal mammary artery in personals with coronary artery bypass grafting. Bilateral internal mammary artery grafting is linked to a higher risk of impaired wound healing, particularly in diabetic individuals, elderly, pedicled preparation, and skeletonized preparation. Nevertheless, caution should be exercised while interacting with its values since examinations were performed by different surgeons with different skills on different types of personals.

Outcomes of Coronary Artery Bypass Grafting With Bilateral Internal Mammary Artery in Obese Patients

BackgroundThe purpose of this study was to evaluate postoperative outcomes with the use of bilateral internal mammary artery (BIMA) conduits in obese patients. MethodsBetween January 2003 and December 2018, 8109 patients underwent isolated coronary artery bypass grafting, including 7218 (89%) treated with single internal mammary artery (SIMA) and 891 (11%) treated with BIMA grafts. Patients were divided into 3 groups according to preoperative body mass index (BMI): normal, BMI <25 kg/m2 (22.2%); overweight, BMI of 25 to <30 kg/m2 (37.2%); and obese, BMI ≥30 kg/m2 (40.6%). In each group, BIMA and SIMA patients were compared to investigate 30-day mortality and postoperative complications. Significant baseline differences were observed between the 3 BMI groups, and such differences were adjusted by inverse probability weighting matching. ResultsThirty-day mortality, deep sternal wound infection (DSWI) rates, and length of hospital stay were 1.4%, 0.5%, and 6.0 ± 9.1 days for the normal group; 0.2%, 1.0%, and 5.5 ± 4.2 days for the overweight group; and 0.9%, 1.8%, and 5.5 ± 4.0 days for the obese group. There was no significant difference in 30-day mortality, incidence of DSWI, and hospital stay between BIMA and SIMA groups, except in the obese group, in which the rate of DSWI was significantly higher in the BIMA patients (3.4% vs 0%; P = .02). ConclusionsBIMA grafts in obese patients can be used without an increase of the 30-day mortality and hospital stay. However, the use of BIMA grafts in obese patients may lead to an increase of postoperative DSWI.

Up-to-Date, Skeletonized or Pedicle Bilateral Internal Mammary Artery; Does It Matter?

In this article, we reported on the up-to-date literature regarding skeletonized bilateral internal mammary artery (BIMA) flow and the effect on sternal perfusion. We also reviewed the pros and cons of the skeletonization technique versus the conventional pedicle technique for harvesting the BIMA. We performed an up-to-date review using the PubMed database, with a specific focus on the contemporary published literature. BIMA skeletonization can preserve the sternal microcirculation, minimize tissue damage, and maintain blood supply to the chest wall at the tissue level. This effect is also apparent in diabetics. Deep sternal wound infection (DSWI) rates are significantly less with skeletonization versus the conventional pedicle technique and are comparable to single internal mammary artery harvesting. Contemporary large-scale studies demonstrate that skeletonization of the BIMA increases conduit length, provides superior flow, reduces the incidence of DSWIs, and improves late survival. Hopefully, this review will increase awareness of the compelling evidence in favor of using skeletonized internal mammary arteries and stimulate increased uptake of BIMA revascularization surgery.

Abstract 13096: Outcomes After Coronary Artery Bypass Grafting With Bilateral Internal Mammary Arteries in Obese Patients

Introduction: The purpose of this study was to evaluate the postoperative outcomes with the use of bilateral internal mammary artery (BIMA) conduits in obese patients. Methods: Between January 2003 and December 2018, 8109 patients underwent isolated coronary artery bypass grafting (CABG) at our institution, including 7218 (89.0%) treated with single internal mammary artery (SIMA) and 891 (11.0%) treated with BIMA. Patients were divided into three groups according to preoperative body mass index (BMI), normal or BMI&lt;25 (22.2%), overweight or 25-BMI&lt;30 (37.2%), and obese or BMI&gt;30 (40.6%). In each group, BIMA and SIMA patients were compared to investigate the thirty-day mortality and postoperative complications. Significant baseline differences were observed between the three BMI groups and such differences were adjusted via inverse probability weighting matching. Results: The thirty-day mortality, deep sternal wound infection (DSWI) rates and length of hospital stay were 1.4%, 0.5%, and 6.0 ± 9.1 days for the normal group, 0.2%, 1.0% and 5.5 ± 4.2 days for overweight group and 0.9%, 1.8% and 5.5 ± 4.0 days for the obese group. There was no significant difference in the thirty-day mortality, incidence of DSWI and hospital stay between BIMA and SIMA groups, except in the obese group where the rate of DSWI was significantly higher in the BIMA patients (3.4 vs 0.0%, p=0.02). Conclusions: BIMA for isolated CABG in obese patients can be used without an increase of the thirty-day mortality and hospital stay. However, the use of BIMA in obese patients may lead to an increase of postoperative DSWI.

Hybrid Coronary Revascularization: Early Outcomes and Midterm Follow-Up in Patients Undergoing Single or Multivessel Robotic TECAB and PCI.

Hybrid coronary revascularization (HCR) is the integration of sternal-sparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients with multivessel coronary artery disease (CAD). It is traditionally performed with single-vessel bypass (left internal mammary artery [LIMA] to left anterior descending artery [LAD]) and PCI but can also be accomplished with multiple arterial grafts using bilateral IMA conduits. We sought to review our HCR experience over an 8-year period with robotic totally endoscopic coronary artery bypass (TECAB) and PCI. Of 694 patients undergoing beating-heart TECAB from August 2013 to June 2022, 306 patients were designated as intention-to-treat HCR candidates. Patients underwent PCI prior to, the same day as, or following TECAB, performed using single or bilateral IMA grafts. We retrospectively reviewed early and midterm outcomes up to 8 years in this cohort of patients. The mean Society of Thoracic Surgeons predicted risk of mortality was 1.5% ± 2.5%. There were 44 patients (14%) who had ≥70% left main disease and 218 patients (71%) who had triple-vessel disease. A total of 193 patients (63%) underwent multivessel grafting (advanced HCR), with 83% bilateral IMA use. Mean operative time was 263 ± 80 min, and mean length of stay was 2.6 days. The mean number of vessels bypassed per patient was 1.7 ± 0.6. The mean number of vessels stented was 1.2 ± 0.5. Of the patients, 84% underwent TECAB first, 14% PCI first, and 2% same-day TECAB/PCI. Mortality was 0.6% (observed to expected ratio: 0.42). Early graft patency was 97% (328 of 339 grafts); LIMA-LAD patency was 98%. At 8-year follow-up (mean 37 ± 26 months), all-cause and cardiac-related mortality were 13% and 2.6%, respectively. Freedom from major adverse cardiac and cerebrovascular events was 92%. In patients with multivessel CAD, integrating robotic single and multivessel TECAB with PCI resulted in excellent early and midterm outcomes. In experienced hands, the robotic endoscopic approach allows the routine use of multiple arterial grafting during HCR.

Long-term survival of single versus bilateral internal mammary artery grafting in patients under 70.

OBJECTIVESAs definitive data from randomized controlled trials comparing the effect on long-term survival of using single internal mammary artery (SIMA) or bilateral internal mammary artery (BIMA) grafting are not yet available, observational studies allow for long-term follow-up in large and representative populations, which might complement the information potentially derived from randomized trials. To compare long-term survival in patients under 70 years of age undergoing SIMA or BIMA grafting.METHODSRetrospective analysis of 3384 consecutive patients under 70 years undergoing primary isolated coronary artery bypass grafting, performed from 2000 to 2015, in a Portuguese level III Hospital. We identified 2176 and 1208 patients from the study population who underwent SIMA and BIMA grafting, respectively. The primary end point was all-cause mortality at 10 years. We employed inverse probability weighting to restrict confounding by indication.RESULTSThe mean age of the study population was 59.4 (± 7.6) years, and 567 (16.8%) were females. Inverse probability weighting was effective in eliminating differences in all significant baseline characteristics. Follow-up was 99.88% complete. The median follow-up time was 12.82 (interquartile range, 9.65, 16.74) years: the primary end point of all-cause mortality at 10 years occurred in 463 patients (21.3%) and 166 (13.7%) in the SIMA and BIMA grafting groups, respectively (hazard ratio, 0.78; 95% confidence interval, 0.66–0.92; P = 0.004).CONCLUSIONSBilateral internal mammary grafting is associated with lower long-term mortality than single internal mammary grafting. Moreover, this survival benefit comes at no increased perioperative morbidity or mortality cost.

DEGREE OF UPTAKE OF ADVANCED SURGICAL TECHNIQUES IN CARDIAC SURGERY - THE ROLE OF AN

<h3>BACKGROUND</h3> Cardiac surgeons have traditionally strived to be innovative while ensuring quality of care. Despite this, the uptake of new, advanced surgical techniques in the pursuit of improved outcomes varies significantly between surgeons and cardiac centres. The purpose of this study was to develop a novel "Innovation Index" to determine the degree of uptake of advanced surgical techniques at a surgical centre. <h3>METHODS AND RESULTS</h3> For the purposes of this study, only non-emergent, first-time procedures being performed at the New Brunswick Heart Centre between 2010 and 2017 were considered. Five procedure categories were identified as being representative of the degree of innovation in most cardiac surgery centres, including: (1) bilateral vs. single internal mammary artery (IMA) for isolated coronary artery bypass grafting (CABG) with >=2 grafts; (2) endoscopic vein harvest (EVH) vs. open vein harvest (OVH) for any CABG with a saphenous vein graft; (3) minimally invasive vs. conventional mitral valve repair (MVrep) or replacement (MVR) for isolated mitral valve disease; (4) mitral valve repair vs. mitral valve replacement for patients with isolated mitral insufficiency; and (5) transcatheter aortic valve implantation (TAVI) vs. isolated surgical aortic valve replacement (SAVR) for severe aortic stenosis. The rates of each innovative procedure vs. a more traditional approach were calculated on yearly basis, and means of the annual rates for each of the 5 procedures were then computed to form the "overall" rate of innovation or the "Innovation Index" for that particular year. P-trend values were then determined using two-sided Cochran-Armitage test and Jonckheere-Terpstra test to determine if trends in innovation were exhibited over time. Over the course of the study period, a total of 285 patients received bilateral IMA vs. 3004 single IMA; 1605 EVH vs. 2736 OVH; 64 minimally invasive MVrep/MVR vs. 115 conventional; 224 MVrep vs. 262 MVR for mitral insufficiency; and 334 TAVI vs. 504 isolated SAVR. While significant increases in uptake of EVH (p < 0.0001), minimally invasive surgery (p=0.04) and TAVI (p < 0.0001) were noted, rates of BIMA declined (p < 0.0001) while rates of MVrep remained relatively static (p=0.51) (Figure 1). When combined, the overall trend was one of increased innovation over time (p=0.006). <h3>CONCLUSION</h3> This study represents the first attempt at devising an "Innovation Index" to determine the degree of uptake of advanced surgical techniques at a surgical centre. This novel metric may be used to compare centres in terms of their willingness to innovate and to identify leaders in practice change.

Multiple Grafting with Single Left Internal Mammary Artery as T-Graft with Itself.

Revascularization strategies might be limited in patients with lack of sufficient bypass graft material and increased risk of wound healing disturbances. In this regard, we present first results of patients treated with left internal mammary artery (LIMA) as T-graft with itself due to left-sided double-vessel disease, elevated risk of wound healing infection, and lack of graft material. Eighteen patients were retrospectively analyzed in this study. All patients received LIMA grafting, and additional T-graft with itself during off-pump coronary artery bypass surgery. The investigation was focused on intraoperative and postoperative outcomes. LIMA-LIMA T-graft was performed in a total of 18 patients. Mean Fowler score accounted for 18.2 ± 2.9. Severe vein varicosis was present in 9 patients, and 38.9% of patients had lacking venous graft material due to prior vein stripping. A total of 2.5 ± 0.5 distal anastomoses were performed. Mean flow of LIMA-left anterior descending anastomosis was 41.72 ± 12.11 mL/min with a mean pulsatility index (PI) of 1.01 ± 0.21. Mean flow of subsequent T-graft accounted for 26.31 ± 4.22 mL/min with a mean PI of 1.59 ± 0.47. Median hospital stay was 7(6.75;8) days. No incidence of postoperative wound healing disorders was observed and all patients were discharged off hospital. LIMA as T-graft with itself to treat left-sided double-vessel disease is feasible and safe in patients with missing bypass graft material and increased risk of deep sternal wound infection. Further prospective studies are necessary to confirm our results.

Safe implementation of robotic-assisted minimally invasive direct coronary artery bypass: application of learning curves and cumulative sum analysis.

BackgroundLearning curves are inevitably encountered when first implementing an innovative and complex surgical technique. Nevertheless, a cluster of failures or complications should be detected early, but not deter learning, to ensure safe implementation. Here, we aimed to examine the presence and impact of learning curves on outcome after robotic-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB).MethodsA retrospective analysis of the first 300 RA-MIDCAB surgeries between July 2015 and December 2020 was performed. Learning curves were obtained via logarithmic regression for surgical time. Cumulative sum (CUSUM) analysis was performed for (I) major complications including MI, stroke, repeat revascularization, and mortality, and (II) other complications, including prolonged ventilation, pneumonia, pleura puncture, lung herniation, pericarditis, pleuritis, arrhythmia, wound complications, and delirium. Expected and unacceptable rates were set at 12% and 20%, respectively, for major complications, and at 40% and 60% for other complications, based on historical data in conventional coronary artery bypass grafting (CABG).ResultsDemographic characteristics did not differ between terciles, except for more smokers in the first tercile, and less hypercholesterolemia and more complex procedures in the third tercile. The mean surgical time for all operations was 258±81 minutes, ranging from 127 to 821 minutes. A learning curve was only observed in the first tercile. Subgroup analysis revealed that this learning curve was only observed for procedures consisting of single internal mammary artery (SIMA) with 1 or 2 distal anastomoses but not with bilateral internal mammary arteries (BIMA) or more than 2 distal anastomoses. CUSUM analysis showed that the cumulative rate of major and other complications never crossed the lines for unacceptable rates. Rather, the lower 95% confidence boundary was crossed after 50 cases, indicating improvement in safety.ConclusionsThese results suggest that integration of RA-MIDCAB in the surgical landscape can be safely achieved and complication rates can quickly be reduced below those expected in traditional CABG. Collective experience plays a key role in overcoming the learning curve when more complex procedures and cases are introduced.

Incidence and Risk Factors for Surgical Site Infection Following Coronary Artery Bypass Graft Procedures

Background: Deep and organ-space surgical site infections (SSIs) are serious complications of coronary artery bypass graft (CABG) procedures. It is unclear whether the use of bilateral versus single internal mammary artery (BIMA vs SIMA) and surgical approach to internal mammary artery (IMA) harvest (pedicled vs skeletonized) are independent risk factors for SSI. The use of BIMA grafting redirects blood flow away from the sternum to the heart and may increase SSI risk due to lower tissue perfusion. A skeletonized approach to graft harvest, wherein the IMA is dissected free of surrounding tissue to preserve collateral sternal blood flow, may decrease SSI risk as compared to a pedicled approach in which the IMA is mobilized within a tissue pedicle. We describe the incidence and potential risk factors for post-CABG SSI in an academic tertiary-care center performing ~500 IMA procedures annually. Methods: Data were abstracted on adult patients who underwent a CABG procedure using at least 1 IMA graft between July 2017 and June 2020. Additional data on potential risk factors for SSI were obtained electronically from hospital data marts and the Division of Cardiac Surgery database, including demographics, comorbidities, number of arterial grafts, surgical approach, surgeon, and discharge location. Using standard NHSN definitions, infection control practitioners identified post-CABG deep and organ-space SSIs. Patient and procedure characteristics were evaluated as potential risk factors for deep and organ-space SSI using the Fisher exact test. Results: Of 1,591 CABG procedures performed during the study period, 1,244 (78.2%) were performed using a SIMA technique and 347 (21.8%) were performed using a BIMA technique. The overall post-CABG SSI incidence was 1.2 per 100 procedures, with 1.0 SSIs per 100 SIMA procedures and 1.7 SSIs per 100 BIMA procedures. Table 1 demonstrates an increase over time in proportion of CABG procedures performed using SIMA and skeletonized IMA grafts. We also observed a decrease in overall SSI incidence over this period. See Table 2 for univariate predictors of post-CABG SSI. Conclusions: Female sex, BMI ≥40, age ≥75 years, diabetes, and discharge to a rehabilitation setting were associated with development of post-CABG SSI. Although the overall incidence of deep and organ-space SSI in our cohort was very low, making it difficult to draw conclusions about potentially modifiable risk factors, an increase in the use of SIMA and skeletonized grafts appears to be accompanied by a decrease in SSI incidence. More data from our institution and others are needed to determine the significance of this trend.Funding: NoDisclosures: None

STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It has been the foundation for quality measurement and improvement activities in cardiac surgery, facilitated the generation of accurate risk adjusted performance benchmarks and serves as a platform for novel research. Recent enhancements have added to the database's functionality, ease of use, and value to multiple stakeholders. This report is the sixth in a series of annual reports that provide updated volumes, outcomes, database-related developments, quality improvement initiatives, and research summaries using the Adult Cardiac Surgery Database in the past year.

Eleven-year outcomes of U-clips in totally robotic coronary artery bypass grafting versus standard hand-sewn running suture in robotic-assisted coronary artery bypass grafting.

The aim of this study was to evaluate the clinical outcomes of patients undergoing off-pump robotic coronary artery bypass grafting (CABG) with either interrupted nitinol U-Clips in totally endoscopic coronary artery bypass (TECAB) or standard running suture anastomosis in robotically assisted direct coronary artery bypass (RADCAB) over a decade. From January 2007 to December 2017, 280 patients underwent robotic off-pump CABG using the da Vinci S/Si Surgical System in our centre. TECAB with interrupted nitinol U-Clips anastomosis was performed in the left internal mammary artery (LIMA) to LAD grafting in 126 patients and RADCAB (n = 154) of the LIMA to LAD was completed with standard running suture. After discharge, patients were contacted through telephone interview and were invited to attend the outpatient clinic every 6 months or 1 year. The graft patency was assessed by coronary angiography or computed tomography angiography. All cases were completed without conversion to median sternotomy or cardiopulmonary bypass. A total of 275 single internal mammary artery (IMA) grafts (271 LIMAs, 4 right internal mammary arteries) and 5 bilateral IMA grafts were used as single graft or composite grafts. All the patients were discharged without in-hospital mortality or adverse outcomes. The average follow-up was 89.7 ± 30.4 months (range, 14-143 months). The cumulative survival rates (P = 0.53), the cumulative IMA patency rates (P = 0.83), and the rates of freedom from major adverse cerebrovascular and cardiovascular events (P = 0.41) between TECAB and RADCAB all showed no significant difference in the follow-up. Robotic off-pump CABG using IMA grafts is safe and can provide reliable long-term outcomes. Compared with the standard hand-sewn running suture technique in RADCAB, interrupted suture with the nitinol U-Clips in TECAB showed similar long-term clinical results and graft patency in LIMA to LAD bypass grafting.

A new way to use transit-time flow measurement for coronary artery bypass grafting.

Transit-time flow measurement is a recognized method for graft evaluation in coronary surgery. However, single flow measurement has been associated with a low specificity for detecting graft dysfunction. The goal of this study was to assess the value of transit-time flow measurement for assessing in situ internal mammary artery grafts during non-existent native coronary circulation and the relevance of collateral blood flow in target vessels. Between 2014 and 2018, a total of 134 patients undergoing on-pump coronary artery bypass grafting were evaluated using transit-time flow measurement. We analysed 111 single left internal mammary artery and 57 single right internal mammary artery bypasses. Correlations between coronary relevant parameters were calculated using Spearman's ρ coefficient. Risk factors for decreased flow with an arrested heart (FAH) <30 ml/min and an increased pulsatility index (PI) >3.0 as well as flow reduction >30% were calculated. FAH correlated with the diameter of the target vessel (Spearman's ρ = 0.32; P < 0.001), the amount of blood distribution (Spearman's ρ = 0.34; P < 0.001), the PI (Spearman's ρ = 0.19; P = 0.019) and the degree of stenosis (Spearman's ρ = -0.17; P = 0.042). The percentage of flow change was found to correlate with the PI (Spearman's ρ = -0.47; P < 0.0001), the degree of stenosis (Spearman's ρ = 0.42; P < 0.001), the diameter of the target vessel (Spearman's ρ = -0.22; P = 0.008) and the area of blood distribution (Spearman's ρ = -0.19; P = 0.018). A small blood distribution area was the only risk factor for decreased FAH [odds ratio (OR) 8.43, confidence interval (CI) 95% (3.04-23.41); P < 0.001]. Binary logistic regression identified PI [OR 2.05, CI 95% (1.36-3.10); P = 0.001], FAH [OR 0.98, CI 95% (0.97-0.99); P = 0.005] and degree of stenosis [OR 0.95, CI 95% (0.92-0.99); P = 0.011] as risk factors for decreased flow after cardiopulmonary bypass (<30 ml/min). An increased PI (>3) was mainly influenced by percentage of flow change [OR 0.99, CI 95% (0.98-1.00); P = 0.031]. FAH and percentage of flow change are related to the dimensions of the target vessel and the degree of stenosis. The addition of flow measurements with the heart arrested provides additional information about the bypass graft, the quality of the anastomosis and the physiology of the coronary circulation.

Application of bilateral internal mammary artery with different configurations in coronary artery bypass grafting

BackgroundA large number of studies have shown that BIMA grafting is superior to single internal mammary artery grafting in cardiac function protection and long-term survival after surgery. While, there is still no consensus on how is the best configuration to use BIMA. This study aims to compare intraoperative blood flow, early clinical results and early postoperative patency of different configurations of BIMA.MethodsThere were 74 patients who underwent CABGs with bilateral internal mammary artery with different configurations we included. According to the different target territories that RIMA grafted to, the patients were divided into bilateral group (group I) with 20 cases and left group (group II) with 54 cases. Intraoperative blood flow, early clinical results and early postoperative patency of different configurations of BIMA were compared.ResultsThere was no difference in the early postoperative death and major complications between group I and Group II(P>0.05). Compared with the LIMA in group II, the LIMA in group I had a slightly higher DF value (76.7 ± 6.2 vs 73.1 ± 6.8, P = 0.040). Compared with the RIMA in group II, the RIMA in group I had a slightly higher MGF (51.7 ± 34.4 ml/min vs 31.4 ± 21.4 ml/min, P = 0.024). There was no difference in the other TTFM parameters of LIMA and RIMA between group I and Group II(P>0.05). Further subgroup analysis revealed that compared with free RIMA in group II, in situ RIMA had a higher DF value (71.4 ± 7.8 vs 61.8 ± 18.1,P = 0.025). The PI of LIMA in free RIMA subgroup was higher than the PI of LIMA in in-situ RIMA subgroup (3.0 ± 1.6 vs 2.1 ± 1.0,P = 0.018). The results of early postoperative CTA examination showed that all IMAs grafts were completely patent.ConclusionsThe use of BIMA for CABG is safe and efficacious, RIMA used in right coronary artery received more satisfactory graft flow. BIMA with no stenosis and occlusion in the early stage, therefore is the ideal and stable coronary bypass graft.

Early Outcomes of Using Radial Artery in Coronary Artery Bypass Surgery in Cairo University Hospitals

Background: Using arterial grafts is commonly associated with good outcome. Using left internal mammary artery and radial artery can achieve complete arterial revascularization of left coronary system by using sequential grafting or multiple Y Technique. Objective: We present our experience in using internal mammary artery and radial artery (RA) Y-graft in 100 patients. Patients and Methods: Between February 2016 and January 2019, 100 patients (aged 45-60 years) with the diagnosis of multi-vessel disease underwent complete arterial revascularization using left internal mammary artery (LIMA) and RA. We used the technique of RA (Y) or (T) graft on LIMA to revascularize left coronary system; we did multiple (Y) or (T) graft or sequential grafts. Results The operating time was 220±20 minutes in average, the bypass time was (92.5 ± 16.7) minutes, and cross-clamp time was (70.6 ± 20.6 minutes). LIMA was anastomosed to the left anterior descending coronary artery (LAD) system in all patients. RA Y-graft was anastomosed to LIMA in all patients. Sequential grating using RA was done in 20 patients. The mean ICU stay of the patients was (2.2 ± 0.5 days). Mean hours of mechanical ventilation was (14.3 ± 2.9). Four patients required re-exploration for bleeding. 66 patients needed blood transfusion. 45 patients required inotropes. Conclusions: RA can be used safely with LIMA to revascularize left coronary territory using sequential grafts or multiple (Y) grafts. This method allows for complete arterial grafting in multi-vessel disease using only single IMA and RA grafts with good early results.

Wound complications and 30-day readmissions after single and bilateral internal mammary grafting: Analysis of the Nationwide Readmissions Database.

This study compares the postoperative outcomes, 30-day readmission rates, and incidence of sternal wound infection-related readmissions between patients receiving bilateral internal mammary arteries (BIMA) and single internal mammary artery (SIMA) grafting during coronary artery bypass graft (CABG) surgery. We utilized the weighted 2013-2014 National Readmission Database claims to identify all US adult patients who underwent CABG utilizing SIMA (n = 279,891) or BIMA (n = 11,651). Thirty-day overall and wound-related readmissions, in-hospital outcomes, costs, lengths of stay (LOS) at readmissions were compared between the two groups. Predictors of 30-day readmission were assessed using multivariable Cox proportional hazards analysis. After propensity matching (n = 10,339 pairs), there were no significant differences between the two groups during the index hospitalization, except for higher total hospital costs in the BIMA group (p = .02). The incidence of wound infections was also comparable between BIMA and SIMA (1.1% vs. 1.2%; p = .50). At 30-days, the overall readmission rate was elevated in SIMA patients (9.5% vs. 8.8%; p < .01), primarily impacted by cardiovascular causes. While the proportion of 30-day readmissions due to infections was significantly higher among BIMA versus SIMA patients (20.4% vs. 15.9%; p < .01), wound infections during the index hospitalization did not predict all-cause 30-day readmission among BIMA patients (p = .24) in the risk-adjusted analysis. Among the readmitted patients, LOS (6.4 vs. 6.2 days), costs ($14,440 vs. $16,461), and in-hospital mortality (2.4% vs. 1.7%) were comparable between the two groups (all p > .05). BIMA grafting is not an independent predictor of all-cause 30-day readmissions. Cardiovascular causes remain the primary driver of 30-day readmissions among SIMA and BIMA patients after CABG.