Operative techniques in awake coronary artery bypass grafting

The effect of erector spinae plane block on arterial grafts in coronary artery bypass grafting

Background

This study aims to evaluate the sympathectomy effects of erector spinae plane block on the diameters and cross-sectional areas of the left and right internal mammary arteries and of the radial arteries.

Methods

This prospective study included a total of 25 patients (14 males, 11 females; median age: 67 years; range, 23 to 75 years) who underwent erector spinae plane block categorized as the American Society of Anesthesiologists Class III and underwent off-pump coronary artery bypass grafting between June 01, 2020 and March 01, 2021. The effects of erector spinae plane block on the diameters and cross-sectional areas of the left and right internal mammary arteries and radial arteries were assessed using ultrasonography images taken both before and 45 min after the procedure, from the third, fourth, and fifth intercostal spaces for the left and right internal mammary arteries and from 3 cm proximal to the wrist for the radial arteries.

Results

The diameters and cross-sectional areas of the left and right internal mammary arteries and radial arteries significantly increased compared to baseline values after the erector spinae plane block (p<0.05). There was no significant difference in the pre- and post-procedural heart rate and mean arterial pressure values (p>0.05).

Conclusion

The bilateral erector spinae plane block, which was performed at the T5 level, provided vasodilatation of the left and right internal mammary arteries and radial arteries without causing any significant difference in the heart rate and mean arterial pressure. These findings indicate that the sympathetic block produced by the erector spinae plane block may facilitate better surgical conditions by preventing arterial spasms. Thus, bilateral erector spinae plane block may be a promising technique to achieve regional anesthesia for off-pump coronary artery bypass grafting.

Regional Anesthesia in Cardiac Surgery: A Friend or A Foe?

Escalating costs and change in the profile of patients presenting for cardiac surgery requires modification of perioperative management strategies. Regional anesthesia has played an integral part of many fast-track anesthesia protocols across North America and Europe. This review suggests that for patients undergoing coronary artery bypass graft surgery, the risk-to-benefit ratio is in favor of epidural and spinal anesthesia, provided there are no specific contraindications and the guidelines for the use of regional techniques in cardiac surgery are followed. Patients managed with regional techniques seem to benefit from superior postoperative analgesia, shorter postoperative ventilation, reduced incidence of supraventricular arrhythmia, and lower rates of perioperative myocardial infarction. The results of this analysis suggest that for each episode of neurologic complication, 20 myocardial infarctions and 76 episodes of atrial fibrillation would be prevented, thus, we would consider the regional anesthesia and analgesia to be an effective strategy that improves perioperative morbidity. However, other treatment modalities such as the addition of calcium channel blockers, aspirin, and beating heart surgery, are also suggested to be beneficial in cardiac surgical patients and may impose less risk than the use of regional techniques. We believe that the results presented in this review are encouraging enough to permit continued investigation. A prospective, randomized, controlled multicenter trial needs to be adequately powered to answer important clinical questions and allow for a long-term follow-up.

[Coronary artery bypass grafting in conscious patients: a procedure with a perspective?]

Patients undergoing coronary artery bypass grafting increasingly show severe co-morbidities, which can negatively affect the outcome. Recent developments in cardiac surgery have therefore focused on minimizing the invasiveness of the procedure by revascularization on the beating heart without cardiopulmonary bypass, and by reducing surgical trauma using smaller surgical incisions. Progress in minimally invasive cardiac surgery has led to minimally invasive anesthesia, i.e. using high thoracic epidural anesthesia as the sole technique in the conscious patient (awake coronary artery bypass grafting, ACAB). Published data on ACAB procedures in smaller cohorts have demonstrated that the procedure is safe. Significant complications occurred in 7.1% of patients. A particular cause of concern during ACAB surgery is the development of spinal epidural hematoma the risk of which has been estimated to be as high as 1:1,000. A thorough risk-benefit analysis has therefore to be made. Currently, ACAB surgery remains limited to few specialized centers and highly selected patients.

Intrathecal and Epidural Anesthesia and Analgesia for Cardiac Surgery

Adequate postoperative analgesia prevents unnecessary patient discomfort. It may also decrease morbidity, postoperative hospital length of stay and, thus, cost. Achieving optimal pain relief after cardiac surgery is often difficult. Many techniques are available, and all have specific advantages and disadvantages. Intrathecal and epidural techniques clearly produce reliable analgesia in patients undergoing cardiac surgery. Additional potential benefits include stress response attenuation and thoracic cardiac sympathectomy. The quality of analgesia obtained with thoracic epidural anesthetic techniques is sufficient to allow cardiac surgery to be performed in awake patients without general endotracheal anesthesia. However, applying regional anesthetic techniques to patients undergoing cardiac surgery is not without risk. Side effects of local anesthetics (hypotension) and opioids (pruritus, nausea/vomiting, urinary retention, and respiratory depression), when used in this manner, may complicate perioperative management. Increased risk of hematoma formation in this scenario has generated much of lively debate regarding the acceptable risk-benefit ratio of applying regional anesthetic techniques to patients undergoing cardiac surgery.

Composite Bilateral Internal Thoracic Artery Grafts via Standard Sternotomy for Lateral Wall Revascularization in Conscious Patients

BACKGROUND

A new technique has been developed that permits complete arterial revascularization of the lateral wall of the heart using in situ bilateral internal thoracic artery grafts in awake patients. This technique, performed without cardiopulmonary bypass or mechanical ventilation, creates the least invasive revascularization method for the lateral wall of the heart yet described.

METHODS

In 4 patients, double or triple vessel coronary artery bypass grafting was performed without general anesthesia. A high thoracic epidural anesthesia was started 1 hour before surgery. Bilateral internal thoracic arteries were harvested and all anastomoses were performed with the off-pump technique via standard median sternotomy. Circumflex branches were anastomosed with the left internal thoracic artery via a heart positioner.

RESULTS

All patients remained awake throughout the whole procedure. There was no perioperative myocardial infarction or mortality. Pneumothorax was observed in only 1 patient and did not hinder the procedure. There were no hemodynamic changes during lateral wall revascularization. Two patients required unexpected coronary endarterectomy during circumflex and right coronary artery anastomoses.

CONCLUSIONS

Complete arterial revascularization via median sternotomy using in situ bilateral internal thoracic artery grafts without general anesthesia is a feasible and safe procedure for multivessel disease. This approach allows for complete coronary artery revascularization in patients with contraindications for general anesthesia with or without cardiopulmonary bypass.

Awake cardiac surgery using a novel anesthetic technique

PURPOSE

We describe the first published cases of awake cardiac surgery in Canada. In addition, a novel anesthetic technique consisting of combined femoral block/high epidural thoracic anesthesia is presented.

CLINICAL FEATURES

Two patients, both 65 yr of age and with good left ventricular function, were scheduled to undergo off-pump coronary artery bypass grafting (OPCAB) for two grafts each. Anesthesia consisted of combined femoral 3:1 block and high thoracic epidural anesthesia. Both surgeries proceeded without hemodynamic or respiratory complications; in both cases, opening of the pleural spaces was treated with insertion of thoracic drainage tubes. Both patients were transferred to the postanesthesia care unit immediately after surgery and six hours later to the cardiac surgical ward. Both patients were discharged from the hospital within five days of surgery.

CONCLUSION

We conclude that awake OPCAB is feasible using a combined femoral block/high thoracic epidural anesthesia technique which allows cardiac surgery and harvesting of the saphenous vein. Further clinical experience is required to define the technical limitations of this technique before randomized studies should be undertaken to better define the role of awake procedures in the future of cardiac surgery.

Reversed-J inferior versus full median sternotomy: which is better for awake coronary bypass surgery

BACKGROUND

The aim of this study was to ascertain whether the approach with a less invasive reversed-J inferior sternotomy could improve intraoperative patient compliance and postoperative recovery than the standard median sternotomy.

METHODS

Seventeen patients underwent elective single coronary artery bypass graft operation under high thoracic epidural anesthesia without endotracheal intubation. The reversed-J sternotomy was performed in 10 patients (Group A) and full sternotomy in 7 patients (Group B). The technical and surgical difficulties, pulmonary functions (by spirometric tests) and hospital stay were assessed.

RESULTS

Through the reversed-J sternotomy coronary revascularization was accomplished without any additional technical difficulties and with a good exposure of both the left anterior descending artery and the left internal thoracic artery. No conversion to standard sternotomy and no intubation were observed. Additional doses of local anesthetic at jugular notch was not required in Group A. Pleura was opened more in Group B (57% vs. 20%; p = 0.14). Oxygen saturation was better in Group A during the surgical procedure (98.8 +/- 0.7% vs. 97.1 +/- 2.1%; p = 0.033), however, intraoperative PaCO2 was similar in both the groups. The patients in Group A were discharged from the hospital earlier (3.2 +/- 1.5 vs. 7.3 +/- 3.5 days; p = 0.004).

CONCLUSIONS

Less invasive approach to coronary artery bypass graft operations is possible through combination of the high thoracic epidural anesthesia and a reversed-J sternotomy. This technique is less traumatic for patient and provides practical better oxygenation and shorter hospital stay.

Comparison of three anesthetic techniques for off-pump coronary artery bypass grafting: General anesthesia, combined general and high thoracic epidural anesthesia, or high thoracic epidural anesthesia alone

OBJECTIVE

This study compared general anesthesia (GA), combined GA plus thoracic epidural anesthesia (TEA), and TEA alone in patients scheduled for off-pump coronary artery bypass grafting.

DESIGN

Prospective, nonrandomized clinical study

SETTING

University hospital.

PARTICIPANTS

Ninety consenting patients undergoing beating-heart coronary artery revascularization with comparable coronary status and left ventricular function.

INTERVENTIONS

GA (n=30) was conducted with propofol, remifentanil, and cisatracurium or combined with TEA (GA+TEA, n=30) or TEA as the sole anesthetic with ropivacaine plus sufentanil (TEA, n=30).

MEASUREMENTS AND MAIN RESULTS

Groups were comparable regarding the surgical approaches and the number of anastomoses. Four patients (GA, n=2; GA+TEA, n=2) who required unplanned cardiopulmonary bypass, and 4 patients in the TEA group who underwent unexpected intubation because of pneumothorax (n=2), phrenic nerve palsy, or incomplete analgesia were excluded from further analysis. Intraoperative heart rate decreased significantly with both GA+TEA and TEA. None of the patients with TEA alone was admitted to the intensive care unit, they all were monitored on average for 6 hours postoperatively in the intermediate care unit and allowed to eat and drink as desired on admission. Postoperative pain scores were lower in both groups with TEA. There were no differences among groups in patients overall satisfaction.

CONCLUSION

Based on the authors data, all anesthetic techniques were equally safe from the clinicians standpoint. However, GA+TEA appeared to be most comprehensive, allowing for revascularization of any coronary artery, providing good hemodynamic stability and reliable postoperative pain relief. Nonetheless, the actual and potential risks of TEA during cardiac surgery should not be underestimated.

Off-Pump Awake Coronary Revascularization Using Bilateral Internal Thoracic Arteries

BACKGROUND

A new technique has been developed that permits complete arterial revascularization of the lateral and/or inferior wall of the heart using in situ bilateral internal thoracic artery grafts in awake patients. This technique, without cardiopulmonary bypass and mechanical ventilation, creates the least invasive revascularization method for the lateral and/or posterior wall of the heart yet described.

METHODS

In 7 patients double or triple vessel coronary artery bypass grafting was performed without general anesthesia. A high thoracic epidural anesthesia was started one hour before surgery. Bilateral internal thoracic arteries were harvested and all anastomoses were performed with the off-pump technique by standard median sternotomy. Circumflex, or the right coronary artery, were anastomosed with bilateral internal thoracic arteries using a heart positioner. Six patients received double bypass grafting and one patient received triple bypass grafts (bilateral internal thoracic arteries and one radial artery).

RESULTS

All patients remained awake throughout the whole procedure. There was no perioperative myocardial infarction or mortality. Pneumothorax was observed in three patients, but it was repaired in two. Only one patient completed the procedure with unilateral pneumothorax. There were no hemodynamic and pulmonary problems during lateral or posterior wall revascularization. Two patients required unexpected coronary endarterectomy during circumflex and right coronary artery anastomoses.

CONCLUSIONS

Complete arterial revascularization by median sternotomy using in situ bilateral internal thoracic artery grafts without general anesthesia is a feasible and safe procedure for multivessel disease. This approach gives a chance for awake revascularization of the right and/or circumflex coronary artery.

Current status of robotically assisted coronary revascularization

This article reviews the current status of totally endoscopic coronary revascularization using telemanipulation systems for robotic assistance. Current challenges in implementing a robotic surgical program are discussed, and application of the technology in both arrested and beating heart procedures is considered.