Association of HbA1c and utilization of internal mammary arteries with wound infections in CABG

Background

Deep sternal wound infection (DSWI) remains a serious complication after coronary artery bypass grafting (CABG). We herein aimed to stratify diabetic patients who underwent CABG using bilateral internal mammary artery (BIMA) for levels of glycated hemoglobin A1C (HbA1c) and compare postoperative outcomes.

Methods

Between January 2010 and August 2020, 4,186 consecutive patients underwent isolated CABG at our center. In 3,229 patients, preoperative HbA1c levels were available. Primary endpoints were wound healing disorder (WHD), DSWI, and 30-day mortality. Patients were stratified according to preoperative HbA1c levels. Patients were further divided into subgroups according to utilization of BIMA.

Results

After adjustment, no differences in mortality and stroke rates were seen between group 1 (HbA1c < 6.5%) vs. group 2 (HbA1c ≥ 6.5%). WHD was more frequent in group 2 [2.8 vs. 5.6%; adjusted p = 0.002; adjusted odds ratio (OR), 1.853 (1.243-2.711)] but not DSWI [1.0 vs. 1.5%; adjusted p = 0.543; adjusted OR, 1.247 (0.612-2.5409)]. BIMA use showed a higher rate of WHD [no BIMA: 3.0%; BIMA: 7.7%; adjusted p = 0.002; adjusted OR, 4.766 (1.747-13.002)] but not DSWI [no BIMA: 1.1%; BIMA: 1.8%; adjusted p = 0.615; adjusted OR, 1.591 (0.260-9.749)] in patients with HbA1c ≥ 6.5%.

Conclusions

Intraoperative utilization of BIMA is not connected with an increase of DSWI but higher rates of WHD in patients with poor diabetic status and HbA1c ≥ 6.5%. Therefore, application of BIMA should be taken into consideration even in patients with poor diabetic status, while identification of special subsets of patients who are at particular high risk for DSWI is of paramount importance to prevent this serious complication.

A systematic review and meta-analysis of internal thoracic artery harvesting techniques: Skeletonized vs pedicled

OBJECTIVES

The aim of this meta-analysis was to compare clinical and angiographic outcomes of skeletonized versus pedicled internal thoracic artery for coronary artery bypass grafting.

METHODS

A comprehensive search on Ovid MEDLINE, Ovid EMBASE and Scopus was performed from inception to December 2022. The primary outcome was follow-up mortality and graft failure. Secondary outcomes were repeat revascularization, cardiovascular death and operative mortality, myocardial infarction, stroke, and sternal wound complications (SWCs). Pooled estimate for follow-up outcomes was summarized as incidence rate ratio (IRR) and 95% confidence interval (CI) while short-term outcomes were pooled as odds ratio (OR) and 95% CI. For all outcomes, inverse variance weighting was used for pooling.

RESULTS

Twenty-eight studies, including 7 randomized trials and 21 observational studies, for a total of 5664 patients in the skeletonized group and 7434 in the pedicled group, were included in the analysis. At a mean weighted follow-up of 4.8 years, there was no difference in mortality between the two groups (IRR 1.14; 95% CI 0.59-2.20). However, the skeletonized group had a higher incidence of graft failure compared to the pedicled group (IRR 1.87, 95% CI 1.33-2.63) but a lower risk of SWCs (OR 0.42; 95% CI 0.30-0.60). There was no difference in short-term outcomes.

CONCLUSIONS

Compared to the pedicled harvesting technique, skeletonization of the internal thoracic artery is associated with higher rate of graft failure and lower risk of SWCs without mortality difference.

Effect of skeletonisation and pedicled bilateral internal mammary artery grafting in coronary artery bypass surgery on post-operative wound infection: A meta-analysis

The results showed that different internal thoracic artery (ITA) was associated with the rate of postoperative wound infection and the severity of pain following coronary artery bypass grafting (CABG). In order to ascertain if there was any genuine difference in the rate of postoperative infection and severity of the pain, we conducted a meta-analysis to evaluate if there was any actual difference in the wound complication that had been identified with the ITA method. Through EMBASE, Cochrane Library and Pubmed, and so forth, we systematically reviewed the results by August 2023, which compared the impact of skeletonised versus pedicled internal mammary artery (IMA) on wound complications following CABG. The trial data have been pooled and analysed in order to determine if a randomisation or fixed-effect model should be applied. The meta-analysis of data was performed with Revman 5.3 software. The results of this meta-study included 252 related articles from four main databases, and nine articles were chosen to be extracted and analysed. A total of 3320 patients were treated with coronary artery transplantation. Based on current data analysis, we have shown that the rate of postoperative wound infections is reduced by the use of the skeletonised internal mammary artery (SIMA) (OR, 1.84; 95% CI, 1.13, 3.01; p = 0.01). But the results showed that there were no statistically significant differences in the post-operation pain score of the patients (MD, 0.09; 95% CI, -0.58, 0.76; p = 0.79). Furthermore, the duration of the operation was not significantly different between the SIMA and pedicled internal mammary artery (PIMA) (MD, 3.30; 95% CI, -3.13, 9.73; p = 0.31). Overall, the SIMA decreased the rate of postoperative wound infection in CABG patients than the PIMA.

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

PURPOSE

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.

METHODS

We performed an up-to-date review using the PubMed database, with a specific focus on the contemporary published literature.

RESULTS

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.

CONCLUSIONS

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.

Pedicled or skeletonized bilateral internal mammary artery harvesting - a meta- analysis and trial sequential analysis

OBJECTIVE

There is varying evidence on the role of skeletonization of internal mammary artery in reducing the risk of sternal wound infections and ischemia following bilateral internal mammary artery grafting. Post-operative clinical outcomes of skeletonized bilateral internal mammary artery versus pedicled bilateral internal mammary artery harvesting in patients undergoing coronary artery bypass surgery were compared.

METHODS

A comprehensive electronic search was conducted using MEDLINE, Scopus, EMBASE, Cochrane database and Google Scholar from inception until 15 June 2020. All studies directly comparing skeletonized and pedicled bilateral internal mammary artery harvesting were included. Meta-analysis and trial sequential analysis were conducted.

RESULTS

Nine studies (one randomized controlled trial and eight observational studies) consisting of 3649 patients (2050 patients with skeletonized bilateral internal mammary artery grafting and 1599 patients with pedicled bilateral internal mammary artery grafting) were included. Pooled effects analysis and trial sequential analysis reported significantly lower risk of sternal wound infection with skeletonized bilateral internal mammary artery harvesting (OR 0.27, 95% CI 0.20-0.51, p < 0.00001).

CONCLUSIONS

Skeletonization reduces the risk of sternal wound infections by preserving vasculature as much as possible. This facilitates its use in patients at high risk of sternal wound infection.

Off-pump Revascularization with Bilateral versus Single Mammary Arteries-A Propensity Score-Matched Analysis

BACKGROUND

Coronary artery bypass grafting is the first-line therapy for severe multivessel coronary artery disease. We aimed to investigate the clinical outcome in patients undergoing isolated off-pump surgery with the single or bilateral internal mammary artery (SIMA or BIMA) approach.

METHODS

We performed a propensity score-matched analysis in 1,852 consecutive patients, aged 50 to 70 years, who underwent myocardial revascularization at our institution between July 2009 and August 2016. Primary end point was the probability of survival.

RESULTS

Mean follow-up was 36.3 (range: 0.1-89.6) months. The probability of survival in the SIMA and BIMA groups was 98.6 and 99.0% at year 1, 92.0 and 92.5% at year 5, and 85.6 and 81.6% at year 7, respectively, with a hazard ratio (HR) of mortality for the BIMA group versus the SIMA group of 0.98 (95% confidence interval[CI]: 0.64-1.52; p = 0.94). There was evidence for interaction between diabetes and study group on mortality risk (HR = 2.59, 95% CI: 1.07-6.23; p = 0.034). Freedom from mediastinitis/wound infection was higher in the SIMA group than in the BIMA group (99.5 and 96.9%, respectively; HR of an event = 6.39, 95% CI: 2.88-14.18; p < 0.001). The corresponding values in the subgroups of diabetic patients were 98.6 and 90.9%, respectively (HR = 6.45, 95% CI: 2.24-18.58; p = 0.001). Mediastinitis/wound infection was associated with increased mortality risk (HR = 2.96, 95% CI: 1.29-6.78; p = 0.010).

CONCLUSION

Overall, our data indicate similar probability of survival up to a maximum follow-up of 7 years by off-pump surgery with the SIMA or BIMA approach. However, in diabetic patients, the clinical outcome indicates caution regarding the use of the BIMA approach.