Eligibility for Minimally Invasive Coronary Artery Bypass: Examination of Epicardial Adipose Tissue Using Computed Tomography

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.

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.

A Novel Approach Using Computed Tomography Angiograms to Predict Sternotomy or Complicated Anastomosis in Patients Undergoing Robotically Assisted Minimally Invasive Direct Coronary Artery Bypass

OBJECTIVE

Robotically assisted minimally invasive direct coronary artery bypass is an alternative to sternotomy-based surgery in properly selected patients. Identifying the left anterior descending artery when it is deep in the epicardial fat can be particularly challenging through a 5- to 6-cm mini-thoracotomy incision. The objective of this study was to evaluate a technique for predicting conversion to sternotomy or complicated left anterior descending artery anastomosis using preoperative cardiac-gated computed tomography angiograms.

METHODS

Retrospective review of 75 patients who underwent robotically assisted minimally invasive direct coronary artery bypass for whom a preoperative computed tomography angiogram was available. The distance from the left anterior descending artery to the myocardium was measured on a standardized "5-chamber" axial computed tomography view. The relative risk of sternotomy or complicated anastomosis was compared between patients whose left anterior descending artery was resting directly on the myocardium (left anterior descending artery to the myocardium distance = 0 mm) with those whose left anterior descending artery was resting above (left anterior descending artery to the myocardium distance > 0 mm).

RESULTS

The average left anterior descending artery to the myocardium distance was 3.2 ± 2.6 mm (range = 0-11.5 mm). Fourteen patients (18.7%) had an left anterior descending artery to the myocardium distance of 0 mm. Of the entire group of 75 patients, 6 (8.0%) required conversion to sternotomy. Four others (5.3%) were reported to have a complication with the anastomosis intraoperatively. For patients with left anterior descending artery to the myocardium distance of 0 mm, the relative risk of sternotomy or complicated anastomosis was 18.0 (95% confidence interval = 4.3-75.6, P = 0.0001).

CONCLUSIONS

In our experience, patients with left anterior descending artery to the myocardium distance of 0 mm were at significantly higher risk of either conversion to sternotomy or technically challenging anastomosis, with 8 (57.1%) of 14 patients in this group experiencing either end point. This novel measurement may be useful to identify patients who may have anatomy, which is not well suited to the robotically assisted minimally invasive direct coronary artery bypass approach.