Min invasive CABG: Single lung vent
Advanced, Organ-Based and Clinical Sciences
Minimally invasive direct coronary artery bypass (MIDCAB) originally describes LIMA takedown and anastomosis to the LAD via anterior thoracotomy, as performed either off-pump on on-pump with femoral CPB cannulation. Other minimally invasive approaches include thoracoscopic and robotic techniques. Minimally invasive coronary artery surgery performed off-pump (i.e. beating heart) requires lung deflation on the side of the surgical incision for exposure and visualization. Lung isolation for these surgeries can be performed with either a double-lumen tube or bronchial blocker via a single lumen tube.
Compared with the typical thoracic surgery with one-lung ventilation, minimally invasive coronary artery surgery requires thoracic insufflation with carbon dioxide. Insufflation pressures are kept low (10-15 mmHg). Hemodynamic consequences include increased CVP, increased PAP, decreased cardiac output, and regional wall motion abnormalities. Management includes IV fluids and vasoactive medications (e.g., norepinephrine, vasopressin, dobutamine, epinephrine, milrinone, dopamine). Increased CO2 absorption from the thoracic insufflation can cause increased PaCO2 and ETCO2 levels. Initiation of femoral-femoral CPB should be considered if complications such as hemodynamic instability, hemodynamic collapse (e.g., CO2 embolization), or uncontrolled surgical bleeding occur.