Impella-Supported Off-Pump Coronary Artery Bypass Grafting (CABG) in a Patient With Severe Mitral Regurgitation: A Case Report

Figure 1. TEE findings after anesthetic induction. The LVEF was 40%, and there was a mild hypokinesis of the left ventricular motion and mild mitral regurgitation flow centrally from the commissure of the mitral valve (asterisk). TEE: transesophageal echocardiography; LVEF: left ventricular ejection fraction

Figure 2. TEE findings after intraoperative heart displacement. Due to the narrowing of the left ventricular cavity caused by heart displacement, the tip of the Impella inlet (arrow) obstructed the supporting tissue of the posterior apex of the mitral valve, resulting in open fixation of the mitral valve and poor junction with the anterior apex, leading to severe MR (asterisk). TEE: transesophageal echocardiography; MR: mitral regurgitation

Figure 3. Changes in blood pressure (BP), heart rate (HR), rSO2 and PaO2 during surgery. The plots show BP (mmHg, left longitudinal axis), HR (times/min, left longitudinal axis), rSO2 (%, left longitudinal axis; left: solid line, right: dotted line), and PaO2 (mmHg, right longitudinal axis; double line). Severe mitral regurgitation developed due to the Impella inserted before surgery interfering with the posterior mitral leaflet after manipulation for cardiac conversion, resulting in a sudden drop in BP. After initiation of ECMO, BP increased, and then bilateral rSO2 and PaO2 in the right upper also increased. After anastomoses, BP and PaO2 were confirmed to be stable, and there was improved cardiac contraction. Consequently, ECMO was removed, and the surgery was completed. SBP, rSO2, and PaO2 at (1) after induction of anesthesia, (2) heart displacement, (3) before V-A ECMO removal, and (4) finished operation, marked in the graph above, are shown in the table, respectively. rSO2: regional oxygen saturation; PaO2: partial pressure of arterial oxygen; ECMO: extracorporeal membrane oxygenation; SBP: systolic blood pressure; V-A ECMO: veno-arterial extracorporeal membrane oxygenation

Figure 4. TTE follow-up findings on postoperative day 8. TTE revealed a LVEF of 52% and severe wall motion loss in the lateral and inferior walls of the left ventricle with no catecholamine support. A mild MR jet was observed centrally from the commissure (asterisk). The maximum flow velocity of MR was 2.38 m/s, and the mean pressure gradient was 23 mmHg. There was no impairment of the supporting tissues of the valve, such as tendon cords or papillary muscles. TTE: transthoracic echocardiography; LVEF: left ventricular ejection fraction; MR: mitral regurgitation