Predictors and Outcomes of Sternotomy Conversion and Cardiopulmonary Bypass Assistance in Minimally Invasive Coronary Artery Bypass Grafting

Comparison of clinical effects of coronary artery bypass grafting between left anterior small thoracotomy approach and lower-end sternal splitting approach

OBJECTIVE

To compare the clinical effects of coronary artery bypass grafting (CABG) between the left anterior small thoracotomy (LAST) and lower-end sternal splitting (LESS) approaches for coronary artery disease.

METHODS

In total, 110 patients who underwent LAST from October 2015 to December 2020 in Tianjin Chest Hospital were selected as the observation group. Patients who underwent the LESS approach during the same period were analyzed. The propensity score was calculated by a logistic regression model, and nearest-neighbor matching was used for 1:1 matching.

RESULTS

The length of hospital stay and ventilator support time were significantly shorter in the LAST than LESS group. The target vessels in the obtuse marginal branch and posterior left ventricular artery branch grafts were significantly more numerous in the LAST than LESS group, but those in the right coronary artery graft were significantly less numerous in the LAST group.

CONCLUSIONS

CABG using either the LAST or LESS approach is safe and effective, especially in low-risk patients. The LAST approach can achieve complete revascularization for multivessel lesions and has the advantages of less trauma and an aesthetic outcome. However, it requires a certain learning curve to master the surgical techniques and has specific surgical indications.

Predictors and outcomes of conversion to sternotomy in minimally invasive coronary artery bypass grafting

Background

This study aims to investigate the risk factors and surgical outcomes of conversion to median sternotomy in minimally invasive direct coronary artery bypass grafting.

Methods

Between January 2017 and July 2022, a total of 274 patients (246 males, 28 females; mean age: 57.0±9.6 years; range, 33 to 81 years) who underwent conventional (n=116) or robot-assisted (n=158) minimally invasive direct coronary artery bypass grafting were retrospectively analyzed. The primary outcome measure of the study was conversion to median sternotomy, and the secondary outcome measures were operative mortality, length of intensive care unit and hospital stay.

Results

Conversion to median sternotomy was required in 26 (9.5%) patients. The most common cause of conversion was intramyocardial left anterior descending artery (27.0%). Among preoperative and operative characteristics, only age was statistically significant risk factor for conversion to sternotomy (odds ratio=1.06, p=0.01). Operative mortality occurred in one patient (0.36%) patient in the entire cohort. The length of intensive care unit and hospital stay was significantly longer in patients requiring conversion to median sternotomy (p=0.002 and p<0.001, respectively). There was no significant difference in other postoperative outcomes between the two groups (p>0.05).

Conclusion

Intramyocardial left anterior descending artery is the most common reason for conversion to sternotomy, and older age increases the risk of conversion. Minimally invasive coronary artery bypass grafting can be performed with satisfactory results, even if it requires conversion to sternotomy.

[Surgical Revascularization of the Myocardium by Minimally Invasive Access]

Median sternotomy is the Gold Standard access for surgical revascularization of the myocardium, but it is not free of complications, especially in patients with multiple comorbidities. Minimally invasive access offers the advantage of avoiding sternotomy, achieving a more accelerated postoperative recovery, with less hospital stay time and a higher level of satisfaction with quality of life. We present the case of a 49-year-old male patient, diabetic, hypertensive, smoker, with multiarterial coronary artery disease, very symptomatic, who underwent surgical revascularization by left mini-thoracotomy.

Initiation and modification of minimally invasive coronary artery bypass grafting

Minimally invasive coronary artery bypass grafting (MICS CABG) via a small left thoracotomy has been proposed as an alternative to standard coronary artery bypass grafting. However, this technique is still limited to skillful surgeons. Off-pump multi-vessel bypass grafting and the use of bilateral internal thoracic arteries are particularly challenging via a small thoracotomy, while they are widely performed via a full median sternotomy. The purpose of this review is to serve as a guide for the proper introduction of MICS CABG in the current era. We examine the advances, current techniques, outcomes and learning curves of MICS CABG and discuss the safe introduction.

Reason and Timing for Conversion to Sternotomy in Robotic-Assisted Coronary Artery Bypass Grafting and Patient Outcomes

Objective

Conversion to sternotomy is a primary bailout method for robotically assisted coronary artery bypass grafting procedures. The aims of this study were to identify the primary reasons for conversion from robotically assisted coronary artery bypass grafting to sternotomy and to evaluate the in-hospital outcomes in such patients.

Methods

Prospectively collected data from February 2004 to April 2017 were reviewed for 72 patients (56 men; mean age = 63.8 years) who required conversion to sternotomy during a robotically assisted coronary artery bypass grafting procedure with planned endoscopic left internal thoracic artery harvest and anastomosis to the left anterior descending on the beating heart.

Results

The overall rate of conversion was 12.4% (72/581). Conversions occurred either during attempted endoscopic left internal thoracic artery harvest (31.9%), during endoscopic left anterior descending isolation (40.3%), during manual isolation and anastomosis of the left anterior descending (19.4%), or after anastomosis due to unsatisfactory flow (8.3%). Overall, the most common reason for conversion was an intramyocardial left anterior descending (43.1%). The median stay in the intensive care unit was 1 day (range = 0–20) and the median hospital length of stay was 5 days (range = 3–43). In-hospital complications included new atrial fibrillation (16.7%), need for blood transfusion (20.8%), mediastinitis (4.2%), postoperative myocardial infarction (2.8%), exploration for bleeding (2.8%), and 1 in-hospital death.

Conclusions

The reasons for conversion were primarily related to anatomical factors that created difficulties for endoscopic left internal thoracic artery harvesting and left anterior descending identification. Patients who required conversion to sternotomy from robotically assisted coronary artery bypass grafting demonstrated acceptable outcomes and low complication rates.

Repeat Revascularization After Minimally Invasive Coronary Artery Bypass Grafting: Is It a Problem?

OBJECTIVE

Minimally invasive coronary artery bypass grafting (MICS CABG) via a small left thoracotomy is a novel technique for coronary revascularization that is increasingly used around the world. However, multivessel MICS CABG is difficult, and concerns about repeat revascularization (RR) have been raised. This longitudinal study describes the rates of RR among patients who have undergone MICS CABG and identifies targets for improvement.

METHODS

A prospective observational study was performed on the 306 MICS CABG patients operated on by a single surgeon from 2005 to 2015. Minimally invasive coronary artery bypass grafting was performed through a small left thoracotomy, using the in situ left internal mammary artery, ± a radial artery, and 1 to 3 saphenous veins anastomosed proximally to the aorta. Patients were followed annually. We examined the difference between the first half and second half of the series to ascertain the effects of a learning curve.

RESULTS

Eighty percent of the procedures were performed off-pump. The median number of grafts performed were 2, and the left anterior descending, diagonals, obtuse marginals, and posterior interventricular artery were the distal targets in 94%, 12%, 44%, and 26%, respectively. The graftability index (#grafts/#diseased vessels) was 0.93. Revascularization of targets smaller than 1.5 mm decreased from 69% to 50% (P = 0.002) between the series' first and second halves. Overall, RR was needed in 21 patients (6.9%) and was performed at a mean ± SD of 1.7 ± 1.6 years postoperatively. The culprit lesion was attributed to the index surgical procedure ("graft-associated") in 52%, to a stent stenosis or progression of native disease in 43%, and was unidentified in 5%. Patients with graft-associated RR had a lower graftability index at operation (0.73 vs 0.94) and more frequent involvement of the circumflex system (0.8 vs 0.3). The overall rate of RR at 3 years decreased from 11% in the first half to 2.6% in the second half (P = 0.001).

CONCLUSIONS

The need for RR is part of the learning curve with MICS CABG, involves a graft in half of the cases, is more common in patients who had a lower graftability index at operation, and markedly improves with experience.

Mid-Term Follow-up of Minimally Invasive Multivessel Coronary Artery Bypass Grafting: Is the Early Learning Phase Detrimental?

OBJECTIVE

Minimally invasive coronary artery bypass grafting (MICS CABG) through a small left thoracotomy is a novel technique for surgical coronary revascularization, which is increasingly being adopted around the world. This study aimed to describe the characteristics and mid-term outcomes of a series of MICS CABG to identify areas for improvement.

METHODS

A prospective longitudinal study was performed on the 306 MICS CABG patients operated on by a single surgeon from 2005 to 2015. Minimally invasive coronary artery bypass grafting used a small left thoracotomy to enable coronary revascularization with a similar configuration to an open sternotomy technique, with left internal thoracic artery harvesting, and hand-sewn proximal radial/saphenous and distal anastomoses, under direct visualization. We compared patients who were operated on during the first and second halves of the series to ascertain the impact of a learning curve on outcomes.

RESULTS

The mean ± SD age was 62 ± 9 years, 87% were male, and 23% had three-vessel disease. Off-pump coronary artery bypass was performed in 80%, and the median number of grafts was 2 (range 1-4). Sternotomy conversion occurred in 3.3%, reoperation for bleeding in 2%, and unplanned, emergency CPB conversion in 1%. Superficial thoracotomy infection, atrial fibrillation, and left-sided pleural effusion requiring drainage were encountered in 2%, 4%, and 4%, respectively. There were no perioperative stroke, myocardial infarction, or death. At a mean ± SD follow-up of 2.8 ± 2.5 years, 97.4% of patients were free from major adverse cardiac and cerebrovascular events. Between the first and latter half of the series, there was a decrease in the rate of conversion to sternotomy (5.2%-1.3%, P = 0.05) and in the mid-term need for repeat revascularization (11% vs 2.6%, P = 0.03). Overall repeat revascularization rate was 2.5% per year. The intensive care unit and hospital lengths of stay (1.6 ± 1.5 vs 1.4 ± 0.9, P = 0.2, and 6.1 ± 2.6 vs 5.6 ± 1.8, P = 0.4) were not statistically different.

CONCLUSIONS

Minimally invasive coronary artery bypass grafting can be safely initiated as a minimally invasive, multivessel alternative to open surgical coronary revascularization, with excellent mid-term results. Learning phase effects were not observed with regard to overall procedural safety, but rather in terms of improved freedom from conversion to sternotomy and from repeat revascularization.