Multidetector computed tomographic angiography in planning of reoperative cardiothoracic surgery

Redo cardiothoracic surgery is associated with increased morbidity and mortality compared with primary operations. Multidetector computed tomographic angiography (MDCTA) delineates the course of previous coronary artery bypass grafts (CABG) and proximity of mediastinal structures to the chest wall. We sought to determine if high-risk preoperative MDCTA findings were associated with greater use of preventive surgical strategies during redo cardiac surgery in patients with prior CABG.

We studied 167 patients (mean age 69 +/- 9 years, 79% men) with prior CABG, referred for redo cardiac surgery, who underwent contrast-enhanced MDCTA to assess CABG location and mediastinal relationship to chest wall. Preoperative risk was determined. Prevalence of high-risk MDCTA findings, use of preventive surgical strategies, frequency of severe intraoperative bleeding, and postoperative mortality were recorded.

Mean risk score was high (7.5 +/- 3). High-risk MDCTA findings included proximity (<1 cm) of right ventricle/aorta to chest wall (24%) or CABG crossing midline in close proximity (<1 cm anteroposteriorly) to sternum (38%). Preventive surgical strategies included surgery cancelled (4%), nonmidline incision (8%), deep hypothermic circulatory arrest (5%), initiation of peripheral cardiopulmonary bypass (11%) and extrathoracic vascular exposure before incision (53%). These strategies were used at a higher frequency in patients with high-risk MDCTA findings versus those without (88% versus 28%, p < 0.0001). Frequency of severe bleeding, graft injuries, and 1-month mortality were 4.4%, 5%, and 2.5%, respectively.

Routine use of preoperative MDCTA to detect high-risk findings has a strong association with adoption of preventive surgical strategies in high-risk patients undergoing redo cardiac surgery.