Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 220

During on-pump CABG, the aorta is cannulated and cross-clamped, and a cardiopulmonary bypass (heart–lung pump) is used between the venae cavae and the aorta. Cardioplegia is then induced, and the pulmonary ventilation is turned off. The arrested heart is not perfused and is thus ischemic: this is reduced by rapid and cold cardioplegia, and limiting “pump time”. Off-pump CABG is performed on a beating heart without cardioplegia and aortic cannulation, although partial aortic cross-clamping is still needed if SVG anastomoses are performed.

Off-pump CABG has the advantage of less bleeding/less requirement for transfusion, less renal failure, less respiratory complications, and probably less stroke as aortic manipulation is limited.^113,114 In fact, in patients with heavy aortic calcifications or atherosclerosis, off- pump CABG with only LIMA or LIMA and RIMA grafting is particularly valuable, as it avoids aortic manipulation. Off-pump CABG is, however associated with less complete revascularization and a higher risk of early ischemia and graft failure.¹¹³ MIDCAB (minimally invasive direct CABG) is a form of off-pump CABG performed through a mini-thoracotomy between two ribs, and mainly consists of single-vessel grafting of the LIMA to the LAD. Off-pump LIMA–LAD may be used as part of a hybrid strategy, where non-LAD disease is treated with PCI.