Satoshi Kurokawa

Clinical features and risk assessment for cardiac surgery in adult congenital heart disease: Three years at a single Japanese center

Abstract Purpose The aims of our study are twofold: first, to retrospectively identify the demographic characteristics and outcomes in cardiac surgery for adult congenital heart disease (ACHD); second, to explore whether certain preoperative examinations are useful for assessing the risk of perioperative mortality and morbidity. Methods Ninety-two ACHD patients who underwent cardiac surgery from 2009 to 2011 were enrolled in the study. The subjects were classified into three groups based on the complexity of the ACHD. We retrospectively collected data on demographics, operations, and postoperative courses. We also collected the results of examinations performed in the three months leading up to the cardiac surgery, including exercise tolerance testing and measurement of brain natriuretic peptide (BNP). Results The 30-day mortality was 3.3%. A remarkable discrepancy was found between subjective assessment and the severity of exercise intolerance by exercise tolerance testing. The NYHA class was 1 or 2 in all but one of 13 patients with moderate-severe exercise intolerance and a high mortality/major complication rate (53.8%). Patients with BNP 100 pg/ml had a significantly higher mortality/major complication rate than patients with BNP < 100 (34.8% vs. 11.5%, p < 0.05), but the sensitivity (53.3%) and positive predictive value (34.8%) were not high enough in themselves to identify patients at high risk of poor outcome. Conclusion Cardiac surgery could be safely performed in most ACHD cases. Exercise tolerance testing can be useful in identifying patients at high risk of mortality or major complications. BNP can be valuable in predicting poor outcomes after cardiac surgery.

Transesophageal echocardiography detection of undiagnosed multiple muscular ventricular septal defects with alteration of shunt flow by right ventricular pacing after an arterial switch operation in a neonate.

A 12-day-old female with transposition of the great arteries and ventricular septal defect (VSD) underwent an arterial switch operation and VSD closure. Written informed consent for this presentation was obtained from her parents. Transesophageal echocardiography (TEE) during the pre-cardiopulmonary bypass (CPB) period confirmed cardiac pathologies consistent with those diagnosed preoperatively, including a large perimembranous VSD and a mildly hypoplastic left branch pulmonary artery (PA) that did not appear to require angioplasty (2.5 m/s of peak velocity on transthoracic echocardiography (TTE)). During the separation from CPB, however, the TEE detected multiple VSDs with left-to-right (L-R) shunting in the apical trabecular septum. These VSDs had not been detected by any of the previous examinations (preoperative TTE, preoperative cardiac catheterization, or pre-CPB TEE) or by direct visual assessment during surgery. Because they were so widely distributed over the trabecular muscular interventricular septum (IVS), it appeared that their surgical closure would be very difficult to accomplish. Meanwhile, preexisting hypoplastic PA in conjunction with distortion of the branch PAs after the Lecompte maneuver resulted in significant PA obstruction (left PA velocity of 3.2 m/s, right PA velocity of 3.0 m/s). At the same time, the aortic root pressure was 62 mm Hg and the right ventricular (RV) pressure was estimated at 58 mm Hg on the basis of a tricuspid regurgitation flow velocity of 3.4 m/s. Thus, pulmonary overcirculation was prevented by mechanisms similar to those seen after PA banding. On the basis of these findings, we concluded that no additional surgery was indicated. As the patient was being weaned from CPB, she suffered from intermittent high-degree atrioventricular block. Our initial attempt to treat the block by atrioventricular sequential pacing achieved only RV apical pacing, because the elevated threshold prevented atrial capture. Later, after the patient was smoothly weaned from CPB with sinus rhythm, her arterial blood oxygen saturation suddenly deteriorated and her circulation collapsed. CPB was quickly reinstituted to stabilize circulation. Thereafter, the same event recurred during each of several attempts to wean the patient from CPB. Eventually, TEE confirmed a switch of the direction of the shunt from L-R in sinus rhythm to mainly right-to-left (R-L) in RV pacing (Figure 1) (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A282; see Appendix for video caption). We then infused isoproterenol to restore a persistent sinus rhythm. Once a sinus rhythm was achieved, no R-L shunt developed, and her circulation remained stable. New information on cardiac pathology provided from intraoperative TEE has the potential to alter surgical management in approximately 2%–7% of patients with congenital heart disease. In another 2%, visual assessment during surgery reveals new abnormalities. The detection of undiagnosed lesions after separation from CPB may only be possible in rare instances. In our patient, the multiple muscular VSDs were detected only after the surgical procedures were completed. The increased differential between the RV pressure and left ventricular (LV) pressure before the termination of the CPB probably increased the sensitivity of the color Doppler in VSD detection. Stauder et al. reported a patient with perimembranous VSD in whom several TTEs and repeated cardiac catheterizations failed to detect an additional large apical trabecular VSD (magnetic resonance imaging incidentally discovered the VSD). We must be aware that apical muscular VSD is a lesion very likely to be missed in preoperative examinations, especially in cases with high RV pressure equivalent to the LV pressure. TEE also detected the development of bilateral PA branch stenoses, a condition that prevented pulmonary overcirculation. This finding contributed to our conclusion that no additional surgery was indicated. In the Lecompte maneuver, PA bifurcation is anteriorly translocated to the neo-aorta. The maneuver has been reported to cause the branch PA stenosis near the point of either left or right PA origin, or at both points, via the distortion of the branch PAs caused by the anterior position of the bifurcation. Our case exhibited a marked R-L shunt during early to mid systole and a marked L-R shunt during late systole in RV pacing, but a somewhat less marked L-R shunt during late systole in sinus rhythm. RV apical pacing is a well-established From the Faculty of Medicine, Department of Anesthesiology, Tokyo Women’s Medical University, Tokyo, Japan.

Effects of olprinone on hemodynamics and oxygen delivery in pediatric cardiac surgery: Magnitude of effects and comparison to milrinone

Abstract Background and objectives Our study seeks to evaluate the effects of olprinone on hemodynamics and oxygen delivery on weaning from cardiopulmonary bypass (CPB) and to compare the effects of olprinone and milrinone. Methods We retrospectively reviewed 50 pediatric patients administered either olprinone or milrinone on weaning from CPB during cardiac surgery. At 0, 15, 30, 60, 90, and 120 minutes (min) after separation from CPB, we collected data on hemodynamics and oxygen delivery. At the same time points, we also recorded the doses of cardiovascular-acting drugs used concomitantly. We analyzed differences among measurement points by one-way ANOVA and differences between two agents groups by two-way ANOVA. Results Olprinone increased systolic blood pressure (sBP) at 120 min in biventricular repair (BV) and from 90 min in Fontan-type operation (FO). Olprinone produced significant stepwise tapering of dopamine from 60 min and dobutamine from 90 min in BV. For BV, olprinone significantly increased central venous oxygen saturation from 30 min; oxygen excess factor at 30 and 120 min; and cerebral tissue oxygen index from 30 min, except at 60 min. Except for a significant increase in sBP and significant tapering of DOA dose at 120 min in BV, milrinone had no effect on any parameters in either type of operation. Comparisons of the two agent groups showed no significant difference in any parameters. Conclusion Olprinone stabilizes circulation and improves oxygen delivery during BV pediatric cardiac surgery. While olprinone may have stronger effects than milrinone in BV, the two agents were comparable for FO.

Differences in brain oxygenation between two sequential cardiac arrests during axillobifemoral bypass in a stanford type A dissecting aneurysm

Abstract ISCHEMIC PRECONDITIONING is a protective mechanism against long-lasting ischemic events after a short period of ischemia in many organ systems.1,2 There has been only one study addressing this phenomenon in the nervous system in humans.3 Several mechanisms of ischemic preconditioning, such as adenosine triphosphate (ATP)—sensitive potassium channel (KATP), reactive oxygen species, and protein kinase C, have been proposed,1 and an animal study revealed that mild cerebral ischemic stress can induce improvement in brain oxygen metabolism detected by near-infrared spectroscopy (NIR) during subsequent ischemia.4 Although there have been several reports using NIR to monitor cerebral oxygenation during cardiac arrest, only hemoglobin saturation was measured.5,6 The dynamic changes of saturation can be useful, and the changes of this value correlated well with brain hypoxia within individuals.7 The readings obtained from the instrument need to be carefully interpreted in clinical medicine, however.7–9 Monitoring of hemoglobin saturation alone may not be adequate for the assessment of cerebral oxygenation because during hypothermic cardiopulmonary bypass, a decreased in tissue oxygenation occurred despite an increase in cerebral oxyhemoglobin (HbO2) concentration.10 There are two types of commercially available NIR instruments that can measure brain oxygenation: tissue saturation instruments, as previously mentioned, and concentration-measuring instruments. Concentration-measuring instruments show the changes of HbO2, deoxyhemoglobin (Hb), sum of HbO2 and Hb (total Hb), and cytochrome aa3 (Cytaa3).11 During brain ischemia, the concentration-measuring instrument shows a decrease of HbO2 accompanied by an increase of Hb.11,12 In addition to the changes of HbO2 and Hb, it has been reported that the changes in total Hb are useful indicators of alterations in cerebral blood volume and that the alterations in total Hb are linearly related to those in cerebral blood flow,13,14 if the concentration of hemoglobin in blood is not changed. A report also indicated that a significant correlation between changes in cerebral blood flow and changes in total Hb was found in human subjects using NIR and positron-emission tomography.15 Cytaa3 is the terminal enzyme of the mitochondrial electron transport chain, the site of electron transfer to molecular oxygen. It has been shown that decreases in phosphocreatine and nucleotide triphosphate (mostly ATP) measured by magnetic resonance spectroscopy correlated closely with decreased Cyaa3 detected by NIR and arterial blood pressure in piglets.12 Monitoring the oxidative status of Cytaa3 may provide a true look at the status of tissue oxygenation inside the neuronal cells,16 if the chromophore path length is not changed. The authors report intraoperative brain oxygenation detected by NIR during an axillobifemoral bypass in a patient with a Stanford type A dissecting aneurysm who experienced two episodes of intraoperative ventricular fibrillation (VF).