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Background Pulsatile perfusion may offer microcirculatory advantages over conventional nonpulsatile perfusion during cardiopulmonary bypass (CPB). Here, we present direct visual evidence of microvascular perfusion and vasoreactivity between perfusion modalities. Methods A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n = 10) or nonpulsatile (n = 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO 2 ) and its recovery during a vascular occlusion test at the following time points: baseline (T 0 ), 30 minutes on CPB (T 1 ), 90 minutes on CPB (T 2 ), 1 hour after CPB (T 3 ), and 24 hours after CPB (T 4 ). Results On the basis of our scoring scale, a shift in microcirculatory blood flow occurred over time. The pulsatile group maintained normal perfusion characteristics, whereas the nonpulsatile group exhibited deterioration in perfusion during CPB (T 2 : 74.0% ± 5.6% versus 57.6% ± 5.0%) and after CPB (T 3 : 76.2% ± 2.7% versus 58.9% ± 5.2%, T 4 : 85.7% ± 2.6% versus 69.8% ± 5.9%). Concurrently, no important differences were found between groups in baseline StO 2 and consumption slope at all time points. Reperfusion slope was substantially different between groups 24 hours after CPB (T 4 : 6.1% ± 0.6% versus 3.7% ± 0.5%), indicating improved microvascular responsiveness in the pulsatile group versus the nonpulsatile group. Conclusions Pulsatility generated by the roller pump during CPB improves microcirculatory blood flow and tissue oxygen saturation compared with nonpulsatile flow in high-risk cardiac surgical patients, which may reflect attenuation of the systemic inflammatory response and ischemia–reperfusion injury.

Controversy exists regarding the optimal perfusion modality during cardiopulmonary bypass (CPB). Here we compare the effects of pulsatile versus nonpulsatile perfusion on microvascular blood flow during and after CPB.High-risk cardiac surgical patients were randomly assigned to have pulsatile (n=10) or nonpulsatile (n=10) flow during CPB. The sublingual microcirculation was assessed using orthogonal polarization spectral imaging. Hemodynamic and microvascular variables were obtained after anesthesia (baseline), during CPB, and post-CPB.Compared with baseline, a normal microcirculatory blood flow pattern was accomplished at all time points under pulsatile flow conditions. Peaking 24 hours postoperatively, a higher proportion of normally perfused microvessels occurred under pulsatile versus nonpulsatile flow (56.0%±3.9% vs 33.3%±4.1%; p0.05). Concurrently, pulsatility resulted in a reduction in the prevalence of pathologic hyper-dynamically perfused vessels (6.0%±3.4% vs 19.6%±8.8%; p0.05). Leukocyte adherence decreased relative to the nonpulsatile group both during and after CPB. Furthermore, peak lactate levels were reduced under pulsatile flow conditions postoperatively.Pulsatile perfusion is superior to nonpulsatile perfusion at preserving the microcirculation, which may reflect attenuation of the systemic inflammatory response during CPB. We suggest the implementation of pulsatile flow can better optimize microvascular perfusion, and may lead to improved patient outcomes in high-risk cardiac surgical procedures requiring prolonged CPB time.

Purpose The technical difficulty of performing the left ventricular apical anastomosis has limited the adoption of aortic valve bypass surgery for the treatment of aortic stenosis. We report the successful use of an automated coring and apical connector device to perform aortic valve bypass surgery. Description A 74-year-old man, with a history of prior coronary bypass surgery with patent grafts and a porcelain ascending aorta, presented with symptomatic critical aortic stenosis. Through a left anterolateral thoracotomy, a valved conduit was anastomosed to the descending thoracic aorta. The automated coring and apical connector insertion device was used to core a plug of apical myocardium and simultaneously insert an 18-mm apical connector into the left ventricular apex. Evaluation There were no procedural complications, cardiopulmonary bypass was not used, and estimated blood loss was minimal. The patient was discharged on postoperative day 5, and at 3-month follow-up demonstrated significant clinical and hemodynamic improvement. Conclusions The automated coring and apical connector insertion device facilitated the safe and effective performance of aortic valve bypass surgery.

Myocardial infarction that is attributed to native coronary artery spasm in the early postoperative phase has rarely been documented. We report three cases of postoperative myocardial infarction secondary to angiographically demonstrated coronary spasm. Native coronary artery spasm is a rare, but important cause of postoperative ischemia and infarction. Suspicious electrocardiographic changes warrant consideration of transesophageal echocardiography to detect unexpected wall motion abnormalities. Established treatments include intravenous or intracoronary infusion of nitroglycerin and calcium channel antagonists, although several new therapeutic agents may also be beneficial. Prompt coronary angiography is the only definitive modality for early diagnosis and targeted treatment.