Abstract
Coronary artery bypass grafting (CABG) remains the most frequently performed cardiac surgery, yet anatomically complex cases present unique technical challenges that significantly impact outcomes. This review focuses on high-risk CABG scenarios defined by patient-specific anatomical constraints, including porcelain aorta, poor conduits and targets, redo-CABG, spontaneous coronary artery dissection (SCAD), and coronary aneurysms. Unlike prior studies emphasizing physiological comorbidities, we highlight how structural complexities alter surgical planning, limit standard techniques, and demand tailored strategies. Perioperative imaging-including computed tomographic angiography and epiaortic scanning-plays a pivotal role in risk stratification and operative planning. For porcelain or atherosclerotic ascending aorta, "no-touch" techniques, axillary cannulation, or hypothermic circulatory arrest and aortic replacement can mitigate embolic risks. Poor conduits and targets necessitate creative revascularization approaches, including composite and sequential grafting and endarterectomy, while redo-CABG requires meticulous sternal re-entry and dissection to avoid injury to cardiovascular structures including patent grafts. SCAD management favors conservative therapy, but surgery is reserved for high-risk anatomies not amenable to percutaneous interventions with substantial myocardial territories at risk, whereas symptomatic and large coronary aneurysms often require complex surgical repair. Across all scenarios, a successful outcome necessitates proper preoperative planning, intraoperative adaptability, and expertise. In this clinical practice review, we shed light on anatomically high-risk CABG cases and present the latest evidence-based and expert-recommended surgical management strategies.