Introduction
The invasiveness of coronary surgery has remained largely unchanged since its initial introduction. Although sternotomy is still considered the gold standard incision for various cardiac conditions, there is still considerable morbidity related to its use and that of cardiopulmonary bypass (CPB), including infection, stroke, reoperation, transfusion, acute kidney injury, and a slow return to full physical activity. In coronary surgery, the development of minimally invasive technique has been limited by difficulty in accessing and performing anastomosis on multiple different areas of the heart through a single small incision, especially on a beating heart or in obese patients. Minimally invasive coronary surgery bypass grafting (MICS CABG) is developed to allow adequate exposure for surgical precision, and complete revascularization in coronary artery bypass from a small thoracotomy incision with or without CPB. This article will review the technical approach this procedure that has been developing over the past decade.
Preoperative evaluation
The success of MICS CABG in the early phase of development requires the combination of multiple elements:
Anatomical
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chest anatomy that would provide good exposure of the heart
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nonatherosclerotic femoral arteries that allow peripheral cannulation should CPB be needed
Physiological
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hemodynamic stability that allow the heart to tolerate hemodynamic changes with manual manipulation
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adequate pulmonary function that allow the patient to tolerance single lung ventilation and changes in positive pressure ventilation
Surgical
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no significant ascending aortic calcification that allow for proximal anastomosis using side-biting aortic clamp or anastomosis assist devices
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adequate target vessel size and quality
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adequate time to allow for perfect anastomosis
Therefore absolute contraindication proposed by McGinn et al. includes:
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severe pectus excavatum or other chest wall deformities
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severe pulmonary disease
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emergency surgery with hemodynamic compromise
History and physical examination are critically important as it helps the surgeon to identify patients with significant vasculopathies that may require further imaging, such as computerized tomography angiogram, to ensure that femoral cannulation would be safe and feasible. It is important to identify these factors when the patient is first evaluated in clinic.
Surgical OR preparation
Close collaboration between anesthesia and surgeon is extremely critical to ensure a successful MVST CABG. The following should be established or administered prior to the start of the procedure:
Anesthetic preparation
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Routine cardiac surgical monitoring: peripheral arterial line, central venous line, and/or pulmonary artery catheter placement. Central venous line to be placed on the left side to avoid the risk of right lung complication that could affect ventilation.
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Paravertebral thoracic (T2–T3) blockade can be considered for better postprocedural pain control.
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Intubation with double-lumen endotracheal tube or the utilization of bronchial blockers allows for left lung ventilation.
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Transesophageal echocardiography (TEE) placement to:
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monitor cardiac function
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help position guide wire-guided femoral arterial and venous cannulas should CPB be used.
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Patient positioning ( Fig. 20.1 ):
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15–30 degrees right lateral decubitus position, using a longitudinal shoulder roll under the left scapula.
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Left arm is elevated over the head using a Krauss arm support with protection pad secured to the right side of the operating table.
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The groins should be accessible for femoral cannulation should CPB be needed.
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Both legs should be accessible for vein graft harvesting.
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In case of using radial artery as a graft conduit, the harvest needs to be completed before the positioning.
