Hideo Shintani

Emergency cardiopulmonary bypass support in patients with severe cardiogenic shock after acute myocardial infarction

SummaryA total of 16 patients who developed severe cardiogenic shock were resuscitated with a percutaneous cardiopulmonary support system (PCPS). The etiology of shock was acute myocardial infarction (n = 7), or post-infarction left-ventricular (LV) free wall rupture (n = 9). After successful resuscitation with the PCPS, 15 patients underwent therapeutic interventions: closure of an LV rupture (n = 9), coronary artery bypass grafting (n = 4), percutaneous transluminal angioplasty (n = 1), and percutaneous transluminal coronary recanalization (n = 1). Of the 16 patients, 14 were weaned from PCPS or standard cardiopulmonary bypass. Six patients survived longer than 30 days, 3 (19%) of whom were discharged from the hospital. The long-term survival rate in the 6 patients who underwent coronary revascularization was 33% (2/6). Of the 9 patients with LV free wall rupture, 1 was discharged from the hospital. Even though it cannot be concluded, from this small number of patients, that cardiopulmonary resuscitation using PCPS improves survival, it appears that PCPS is a powerful resuscitative modality for seriously ill patients with acute myocardial infarction or LV rupture.

Timing of operation for aortic regulation: Relation to postoperative contractile state

With angiography and pressure measurement, we determined left ventricular volume, wall stress, and systolic performance in 30 patients with aortic regurgitation before and after successful aortic valve replacement. End-systolic wall stress was greatly elevated preoperatively and decreased to normal postoperatively. Systolic pump performance assessed as ejection phase indexes was severely depressed preoperatively and improved to normal or near-normal postoperatively in most patients. The ratio of end-systolic wall stress to end-systolic volume index (ESS/ESVI), an index of myocardial contractility, was greatly decreased before operation. Postoperatively, the ratio increased in all patients, becoming normal in 12 of the 13 patients who had a preoperative ESS/ESVI of 2.9 or greater. However, 15 of 17 patients in whom the ESS/ESVI ratio was less than 2.9 still had subnormal ratios, which indicates the presence of irreversible contractile dysfunction. Stepwise multivariate analysis showed that preoperative ESS/ESVI was the only independent discriminator of postoperative normalization of the contractile function as assessed by ESS/ESVI. After aortic valve replacement, myocardial contractile state does not return to normal in a considerable number of patients. It is important to offer aortic valve replacement for aortic regurgitation before the chance for a good functional result is lost. The ESS/ESVI ratio may be a useful index in determining the timing of operation in patients with aortic regurgitation.

Relation of impaired left ventricular function in mitral regurgitation to left ventricular contractile state after mitral valve replacement

To reevaluate the postoperative contractile state and survival, 34 patients (19 men and 15 women; average age 45 years, range 23 to 65) undergoing conventional mitral valve replacement between 1980 and 1990 were studied. There were 5 cardiac deaths (2 early and 3 late). Four of 5 deaths occurred in patients who had a preoperative left ventricular end-systolic volume index > 100 ml/m2. Sixteen patients with an end-systolic volume index < 100 ml/m2 (group I), and 5 with an index > 100 ml/m2 (group II) underwent repeat catheterization 8 months (range 4 to 17) after surgery. The ratio of end-systolic wall stress to end-systolic volume index increased significantly after surgery in group I, whereas it remained reduced in group II. The postoperative end-systolic wall stress/volume index ratio correlated significantly with the preoperative end-systolic volume index (p < 0.001). In the relation between end-systolic wall stress and ejection fraction, all patients in group II had values that were less than the 95% confidence limits for the normal relation. In conclusion, patients with a preoperative end-systolic volume index > 100 ml/m2 appeared to be at high risk of incurring irreversible depressed myocardial contractility, with a high postoperative mortality.

Improved Management of Selective Cerebral Perfusion in Aortic Arch Surgery

To establish a safe and reliable method for cerebral protection in aortic arch surgery, the authors attempted antegrade selective cerebral perfusion (SCP) based on the characteristics of jugular venous oxygen saturation (SjO2). Twenty patients were divided into two groups: a control group and SCP group. In the control group, in 13 adult patients undergoing cardiac surgery using standard hypothermic cardiopulmonary bypass, the relationship between SjO2 and nasopharyngeal temperature (NPT) during rewarming showed an inverse linear correlation:SjO2 = -2.3 NPT + 133 (r = 0.616). In the SCP group, seven patients with aortic arch aneurysm underwent surgery using SCP performed through direct cannulation of the innominate and left carotid arteries. While on SCP (83 +/- 24 min), the blood was warmed from 28 to 36 degrees C. Cerebral perfusion pressure of 40-60 mm Hg was necessary to maintain the SjO2 equal to the value in the control group at each NPT during SCP in all seven patients. None of the patients had any post operative complications. Our experience suggests that SCP can be safely performed at both mild hypothermia and normothermia under monitoring of perfusion pressure and SjO2 in aortic arch surgery.

Anesthesia for acute pulmonary embolism.

Administration of prostaglandin E1 (PGE1) for pulmonary hypertension shows inconsistent and unpredictable results. This report describes an emergency operation to remove large right atrial thrombi accompanied by pulmonary hypertension, which had caused right ventricular failure. The continuous administration of PGEI together with dopamine resulted in improved arterial blood gas data and cardiac output during and after operation. Intraoperative esophageal echocardiogram was found useful for detection of the clot moving out from the right atrium.

Staged Cardiac and Aortic Aneurysm Surgery Using Ventricular Assist Device

A two-stage procedure involving coronary artery bypass grafting and aortic valve replacement followed by abdominal aortic aneurysm repair two days later was performed on a 51-year-old man with severely depressed left ventricular function. The patient was supported with a left ventricular assist device as a short-term bridge between the two stages of surgery. This strategy may be a useful alternative to a one-stage operation in high-risk patients.

Evaluation of a new finger-type intraoperative epicardial echocardiographic probe for infants and small children.

A new finger-type epicardial echocardiographic probe was evaluated in 26 children with complex cardiac anomalies during open heart surgery. The probe is a small 3.75 MHz phased array transducer for 2-dimensional echo and color Doppler imaging. The tip is slightly angled to facilitate the apical approach through a median sternotomy. The patients included 4 neonates and 8 infants, and the major cardiac lesions were complete atrioventricular (AV) canal, transposition of the great arteries, double outlet right ventricle, and others. The intraoperative study was possible in most of the patients facilitating various approaches for the assessment of left-sided AV valve function, left ventricular outflow obstruction, residual shunt and intraatrial anatomy. Four patients received subsequent operative procedures after the assessment. This transducer appears to be useful in the intraoperative study during surgery for complex cardiac anomalies in neonates and small infants.