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The coronary artery bypass graft (CABG) procedure is used to improve blood flow to at-risk areas of myocardial tissues. When a patient requires subsequent CABG procedures, they may require additional perioperative management techniques and considerations. CABG is one of the most common cardiac procedures undertaken nowadays. With an aging population and high prevalence of coronary artery disease, a percentage of patients will require a second intervention which is mostly carried out in the form of percutaneous coronary intervention. Few will require a redo CABG for various reasons, which carries significant risk as a redo procedure and requires specific measures for work up to avoid complications. This activity reviews the management of patients undergoing a redo CABG procedure and explains the role of the interprofessional team in managing patients who undergo redo CABG. Objectives: Identify the indications of repeat revascularisation. Review the challenges anticipated with redo sternotomy in general and redo CABG in particular. Describe the surgical approach and myocardial protection strategy in redo CABG as well as conduit selection. Summarize the importance of secondary prevention measures. Access free multiple choice questions on this topic.

Advances with percutaneous coronary interventions have led to a reduction in repeat coronary artery bypass grafting.[1] As the population ages, the risk profile of these patients increases, creating a challenging situation for the surgeon and the team involved. Redo sternotomy increases the risk of mortality due to the increased risk of graft injury and subsequent myocardial injury upon sternal re-entry. Redo coronary revascularisation provides a peculiar challenge to cardiac surgeons and carries one of the highest mortality rates amongst redo cardiac surgeries, either isolated or in combination with other pathologies. This requires the establishment of a solid indication in the absence of any other alternative as well as specific work up to obtain the relationship between different anatomical structures, including previous patency and location of grafts.[2][3][4] Another challenge that the surgeon faces in this situation is that of myocardial preservation in the presence of patent coronary artery grafts. During cardiopulmonary bypass, the most common way to preserve the myocardium is by applying a cross-clamp to the ascending aorta diverting the blood from the heart-lung machine away from the heart towards the rest of the body and infusing a cold, potassium-rich solution in the aortic root to perfuse the coronaries and arrest the heart in diastole; bringing down the metabolic activity. The presence of patent grafts maintains a continuous flow of normal warm blood with low potassium content to the heart, which negates the protective effects of cardioplegia and restores electrical activity leading to a resumption of cardiac contractility. The isolation of any patent grafts is, therefore, crucial for a successful redo CABG to allow for a safe procedure.[5]

The biggest complication risk with a redo CABG is typically associated with the repeat sternotomy. Because of the scaring and adhesions that form after an initial sternotomy, a surgeon loses the definitive planes and anatomical clarity they may have experienced during the primary surgery. Complications of repeat sternotomy and dissection can include damage to the heart itself, the coronary vasculature (to include the still patent bypass grafts), the great vessels, the lungs, and any surrounding nerves (i.e., phrenic).[13] In addition, repeat CABG is often associated with higher bypass times, likely because of more extensive dissections and ischemic myocardium. Therefore, increased bypass time leads to increased inflammatory response, increased risk of infection, and increased coagulopathy. Finally, because of the higher chances of needed blood products during surgery, they are at an increased risk of transfusion reactions.[14][15] Another risk associated with redo sternotomies where previous grafts present is intraoperative myocardial infarction due to thrombus dislodgment during manipulation of venous grafts, which carry a higher risk of thrombosis compared to arterial grafts.[16]

There is no doubt that the complexity of heart disease is on the rise. An aging population means an increased chance of second intervention with the increased use of percutaneous approaches. This is associated with a higher rate of comorbidities at the time of presentation. The introduction of heart teams is a recent approach in cardiac surgery; however, it has proven crucial in patients' outcomes, especially in complex cases.[17] Although not extensively studied, the utilization of heart teams for patient selection for randomization in some RCTs showed the benefit of this approach.[18] The involvement of a heart team was suggested to provide better long term outcomes compared to blind randomization, as shown in the results of the EAST registry.[19] The level of evidence when it comes to heart team involvement remains expert opinion (Level 5) due to the lack of large RCTs to compare results with and without the involvement of heart teams; however, the recommendation is Class 1 in consecutive guidelines since 2010.[20] The benefit of a heart team is more pronounced in redo CABG, which is a major encounter for both the patient and the team involved. Decisions about the best timing and method of intervention are usually discussed in an MDT meeting to involve cardiologists, cardiac surgeons, anesthetists, perfusionists as well as nursing staff. The presence of a cardiothoracic radiologist is very important due to the complexity of the anatomical relationships in redo cases. Preoperative assessment is crucial, which is usually done either in outpatient or inpatient settings by dedicated staff. This extends beyond the medical review to the patient's social circumstances and needs. Early involvement of physiotherapy and family liaison services ensure a plan is in place for when patients are out of the hospital. The decision of surgery is usually communicated to the patient by the surgical team after the MDT results. The consenting process requires great interpersonal skills, and the involvement of the patient's family is of great help. Discussion between the surgeon, anesthesiologist, and perfusionist usually takes place prior to the procedure to determine the best cardiac protective strategies for the patient and bail out options in case of complications.

Preoperative assessment is crucial, which is usually done either in outpatient or inpatient settings by dedicated staff. This extends beyond the medical review to the patient's social circumstances and needs. Early involvement of physiotherapy and family liaison services ensure a plan is in place for when patients are out of the hospital. The decision of surgery is usually communicated to the patient by the surgical team after the MDT results. The consenting process requires great interpersonal skills, and the involvement of the patient's family is of great help. Discussion between the surgeon, anesthesiologist, and perfusionist usually takes place prior to the procedure to determine the best cardiac protective strategies for the patient and bail out options in case of complications. Postoperative care requires plans to be put in anticipation by the treating team, which involves surgeons, anesthesiologists, pharmacists, physiotherapists, and microbiologists. Involving other specialties is needed in some cases, such as nephrology, neurology, and hematology, with various complications arising postoperatively. Teamwork in cardiac surgery is fundamental to achieve the desired outcome for each surgical procedure.

Nursing staff plays a fundamental role in the care after redo cardiac surgery: Some units recruit specialized nursing staff for preoperative clinical and social assessment. Postoperative care requires a high degree of experience and diligence by the nursing staff to be able to foresee possible complications early during the course of treatment. Advanced practitioners such as advanced nurse practitioners and surgical care practitioners are involved deeper in patients' care than before, and the subspecialization in cardiac surgery provides continuity of care to the patients. Allied healthcare professionals such as physiotherapists and social care provide the patient with means of fast recovery and advice clinicians on the safety of patients to be discharged.

Different pathways have been developed to facilitate interprofessional communication and monitoring. These pathways provide standardized protocols of care to eliminate human errors as much as possible. The use of clinical audit cycles by clinicians or nursing staff gives insights on different aspects of practice within the units, and all members of the heart team are encouraged to participate in these activities.