Ing-Sh Chiu

Efficacy of Ultrafiltration in Removing Inflammatory Mediators During Pediatric Cardiac Operations

BACKGROUND Conventional and modified ultrafiltration was used in pediatric cardiac operations to reduce volume overload and total body water. The purpose of this study was to compare the efficacy of these techniques in removing inflammatory mediators during cardiopulmonary bypass. METHODS Fifty pediatric patients undergoing cardiac operations were randomized into a modified or conventional ultrafiltration group. Blood samples were obtained before and after ultrafiltration to assess the plasma concentrations of leukocyte elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8. RESULTS Except for plasma concentrations of tumor necrosis factor-alpha in the modified ultrafiltration group, the plasma concentrations of all the mediators measured increased after ultrafiltration in both groups of patients. The volume of ultrafiltrate and the total amounts of tumor necrosis factor-alpha and interleukin-6 removed by ultrafiltration were significantly greater in the modified group. The concentrations of mediators in the ultrafiltrate and the ratio of ultrafiltrate to plasma concentrations of the mediators did not differ between the groups. Ultrafiltration was more efficient in removing tumor necrosis factor-alpha than the other mediators. CONCLUSIONS The efficacy in removing the inflammatory mediators generated during cardiopulmonary bypass did not differ between modified and conventional ultrafiltration.

Extracorporeal membrane oxygenation rescue for cardiopulmonary resuscitation in pediatric patients

Objective:To describe survival and neurologic outcome and identify the factors associated with survival among pediatric patients following extracorporeal cardiopulmonary resuscitation (ECPR) for in-hospital cardiac arrest. Design:Retrospective study. Setting:A university-affiliated tertiary care hospital. Patients:Eligible patients were ≤18 yrs of age and received extracorporeal membrane oxygenation during active cardiopulmonary resuscitation for in-hospital cardiac arrest. Interventions:Extracorporeal membrane oxygenation (ECMO) during active cardiopulmonary resuscitation. Measurements and Main Results:The primary outcome was survival to hospital discharge. The secondary outcome was neurologic status after ECPR at hospital discharge and late follow-up. Good neurologic outcome was defined as Pediatric Cerebral Performance Categories 1, 2, and 3. Continuous variables were expressed as medians (interquartile range). We prospectively defined the early cohort (January 1999 to December 2001) and late cohort (January 2002 to January 2006) and compared the survival rates. We identified 27 ECPR events. The survival rate to hospital discharge was 41% (11 of 27). The nonsurvivors had higher pre-cardiopulmonary resuscitation serum lactate levels (14 [10.2–19.6] mmol/L vs. 8.5 [4.4–12.6] mmol/L, p < .01), longer durations of cardiopulmonary resuscitation (60 [37–81] mins vs. 45 [25–50] mins, p < .05) with longer activating time for ECMO (12.5 [7.5–33.8] mins vs. 5 [0–10] mins, p < .01), and more renal failure after ECPR (68% [11 of 16] vs. 9% [1 of 11], p < .01). The survival rate of the late cohort was better than that of the early cohort (58% [11 of 19] vs. 0% [0 of 8], p < .05). By exact multiple logistic regression analysis, the early cohort and renal failure after ECPR were two independent risk factors for mortality. Among the 11 survivors, ten had good neurologic outcomes. Conclusions:ECPR successfully rescued some pediatric patients who failed rescue with conventional in-hospital CPR. Good neurologic outcomes were achieved in the majority of the survivors. Early cohort and post-ECPR renal failure were associated with mortality.

Rescue for acute myocarditis with shock by extracorporeal membrane oxygenation.

BACKGROUND Acute myocarditis (AM) complicated with refractory cardiogenic shock carries a very high mortality. We report our experience in treating these patients, who were rescued by extracorporeal membrane oxygenation (ECMO) and intravenous immunoglobulin. METHODS Over a 5-year period, 5 patients with AM were rescued with ECMO in our hospital. Femoral venoarterial ECMO was performed in 4 patients, and right atrium-left atrium-aorta ECMO in the other 1 due to ventricular dysfunction. Hemofiltration was applied to 3 patients. Marked elevated creatine kinase, its MB form, and troponin T (TnT) were found before ECMO. RESULTS All the patients could be weaned off the ECMO after 140.0+/-57.7 hours of ECMO support. One patient died of multiple organ failure 10 days later after removal of ECMO, resulting in a 20% mortality. Renal function returned to normal in all survivors. The 4 survivors were discharged uneventfully in 23.3+/-8.3 days and resumed functional class I status. The TnT level declined to the low level within 3 days (slope -4.94+/-1.18 ng/mL/day), and might be an indicator of good recovery of myocardium. CONCLUSIONS ECMO can provide an effective and simple treatment for critical AM with a satisfactory result and reduce the possibility of progressive cardiomyopathy.

Experience with extracorporeal life support in pediatric patients after cardiac surgery.

Extracorporeal life support (ECLS) had been successfully used in neonatal respiratory failure, but cardiac ECLS has been used increasingly in recent years. The purpose of this study was to review our experience in pediatric patients supported by ECLS for postoperative circulatory failure and to analyze the factors associated with mortality. Between January 1999 and December 2004, 68 pediatric patients (< 18 years old) who received ECLS within 7 days after cardiac surgery at the National Taiwan University Hospital were included in this study. The overall survival rate of this cohort was 32.4%. Age and gender did not affect survival. Patients with separate biventricular physiology had a higher probability of survival than those with systemic-pulmonary shunt or cavopulmonary anastomosis (41.3% vs. 13.6%, p < 0.05). Acute renal failure during ECLS was significantly associated with mortality (83% vs. 33.5%, p < 0.001). After ECLS initiation, the lowest lactate levels on the second to fourth days were lower in survivors than in nonsurvivors (2.4 vs. 3.3 mmol/L, p < 0.05). There was a trend toward a better survival in the most recent 2 years in comparison with the previous 4 years (47.6% vs. 25.5%, p = 0.07), although this trend did not reach statistical significance. In conclusion, nonbiventricular physiology, acute renal failure, and high blood lactate levels after ECLS increased the risk of mortality for pediatric patients requiring ECLS for postoperative cardiac support.

Usefulness of Electron Beam Computed Tomography in Children With Heterotaxy Syndrome

Children with heterotaxy syndrome frequently have complex cardiac and noncardiac malformations requiring detailed diagnostic evaluation for management planning. Direct delineation of these structures by electron beam computed tomography (EBCT) is validated as a means of diagnosis. From July 1995 to March 1997, 32 patients (16 girls, 16 boys) with clinically impressed heterotaxy syndrome were enrolled in this study. After evaluation by echocardiography, EBCT studies were performed. Interpretation of cardiac anomalies was performed by sequential analysis based on these cross-sectional images. The diagnoses were subsequently confirmed by angiocardiography and surgical findings. Twenty-eight patients had bilateral trifurcated bronchi, and most of these (24 of 28) did not have a spleen. Four patients had bilateral bifurcated bronchi, 2 patients had polysplenia, and the other 2 patients had a lobulated single spleen. We found that laterality could be identified by EBCT in all patients. Comparison of diagnostic yield between echocardiography, catheterization, and EBCT showed that EBCT is superior to echocardiography and catheterization in demonstration of pulmonary venous anatomy and presence of a very small rudimentary ventricle. In addition, associated visceral, bronchopulmonary, mediastinal, and intracardiac anomalies could all be clearly delineated by EBCT at the same time. Thus, EBCT is a promising complementary modality for an overall understanding of heterotaxy syndrome.

Eleven years of experience with extracorporeal cardiopulmonary resuscitation for paediatric patients with in-hospital cardiac arrest.

PURPOSE The study aims to describe 11 years of experience with extracorporeal cardiopulmonary resuscitation (ECPR) for in-hospital paediatric cardiac arrest in a university affiliated tertiary care hospital. METHODS Paediatric patients who received extracorporeal membrane oxygenation (ECMO) during active extracorporeal cardiopulmonary resuscitation (ECPR) at our centre from 1999 to 2009 were included in this retrospective study. The results from three different cohorts (1999-2001, 2002-2005 and 2006-2009) were compared. Survival rates and neurological outcomes were analysed. Favourable neurological outcome was defined as paediatric cerebral performance categories (PCPC) 1, 2 and 3. RESULTS We identified 54 ECPR events. The survival rate to hospital discharge was 46% (25/54), and 21 (84%) of the survivors had favourable neurological outcomes. The duration of CPR was 39±17 min in the survivors and 52±45 min in the non-survivors (p=NS). The patients with pure cardiac causes of cardiac arrest had a survival rate similar to patients with non-cardiac causes (47% (18/38) vs. 44% (7/16), p=NS). The non-survivors had higher serum lactate levels prior to ECPR (13.4±6.4 vs. 8.8±5.1 mmol/L, p<0.01) and more renal failure after ECPR (66% (19/29) vs. 20% (5/25), p<0.01). The patients resuscitated between 2006 and 2009 had shorter durations of CPR (34±13 vs. 78±76 min, p=0.032) and higher rates of survival (55% (16/29) vs. 0% (0/8), p=0.017) than those resuscitated between 1999 and 2002. CONCLUSIONS In our single-centre experience with ECPR for paediatric in-hospital cardiac arrest, the duration of CPR has become shorter and outcomes have improved in recent years. Higher pre-ECPR lactate levels and the presence of post-ECPR renal failure were associated with increased mortality. The presence of non-cardiac causes of cardiac arrest did not preclude successful ECPR outcomes. The duration of CPR was not significantly associated with poor outcomes in this study.

Balloon angioplasty for obstructed modified systemic-pulmonary artery shunts and pulmonary artery stenoses

OBJECTIVES The results of percutaneous balloon angioplasty for obstructed modified Blalock-Taussig (BT) or central shunts and pulmonary artery (PA) stenoses were studied to assess its role as an alternative to second shunt and surgical PA angioplasty. BACKGROUND Obstruction of a modified shunt and PA stenosis related to the shunt or ductus are not infrequent. A second shunt with or without PA angioplastv is required if the PA size, morphology or age of the patient is suboptimal for definitive surgery. METHODS From June 1994 to May 1999, balloon angioplasty for obstructed systemic-to-PA shunts was performed in 46 patients, with ages ranging from 1 month to 7.4 years (2.2 +/- 1.9 years). Among the 46 patients, 32 had modified BT shunts, 5 had bilateral shunts, 7 had modified central shunts, and 2 had both modified BT and central shunts. Stenoses were seen in 27 main branch PAs, and interruption was present in three. A concurrent balloon angioplasty was attempted in 28 main branch PAs, but it was performed in only 25 vessels. RESULTS Balloon dilation for obstructed modified shunts was considered to be effective in 42 patients (91%), while angioplasty for PA stenosis was effective in 14 vessels and not effective in 11 vessels. After balloon dilation angioplastv, oxygen saturation in the aorta increased from 74.4 +/- 4.3% to 80.8 +/- 3.6% (p < 0.01) in these 46 patients. One patient died of pneumonia. Eight patients required an additional modified BT shunt soon after the procedure because of severe stenosis or interruption at main branch PA. After a mean follow-up period of 11.6 +/- 5.4 months, 29 patients underwent a repeated imaging study to evaluate the morphology and size of the PAs. Of these 29 patients, 26 underwent open-heart surgery, with two mortalities. CONCLUSIONS When a second shunt is under consideration because of obstruction of the modified shunt, balloon angioplasty is a possible alternative procedure. Pulmonary artery stenosis, if present, can be simultaneously dilated.

Evolution of coronary artery pattern according to short-axis aortopulmonary rotation: A new categorization for complete transposition of the great arteries

OBJECTIVES We studied the correlation between coronary artery pattern and aortopulmonary rotation in complete transposition of the great arteries. BACKGROUND Classifications of the coronary arteries in complete transposition are puzzling and incomplete. METHODS Coronary artery anatomy and relation of the great arteries were identified at angiography, echocardiography, surgical intervention or autopsy in 76 patients with complete transposition from 1988 to 1993. Five main types (type 0 and Shaher types 1,2,4 and 9) and their similar variants of epicardial configuration were categorized into five patterns (O, I, II, IV and IX). In addition, data from 568 cases from published reports were collected for analysis. RESULTS As the aorta rotated from a left anterior to a directly anterior location relative to the pulmonary trunk, the left anterior descending coronary artery arose from the left-hand sinus together with the right coronary artery (type 0, one case decreased to no cases); then it gradually shifted to the left to have the same origin as the left circumflex coronary artery from the right-hand sinus (type 1, 10 cases increased to 146, p < 0.0003). When the aorta rotated farther clockwise from directly anterior to right anterior (type 1, 146 cases increased to 235; type 2, 9 cases increased to 50, p < 0.0006) or from right anterior to right lateral (type 1, 235 cases decreased to 6 cases; type 2, 50 cases decreased to 20, p < 0.00000), the left circumflex coronary artery tended to move retropulmonically and originated from the left-hand sinus with the right coronary artery (type 2). When the aorta moved from right anterior to right lateral (type 2, 50 cases decreased to 20; type 4, 13 cases increased to 14, p < 0.031) or from right lateral to right posterior (type 2, 20 cases decreased to 1; type 4, 14 cases increased to 16, p < 0.0003), the right coronary artery shifted to the right-hand sinus anteaortically to join the left anterior descending coronary artery (type 4). Finally, the left anterior descending coronary artery combined with the left circumflex coronary artery (type 9, 12 cases increased to 21, p = 0.407) to become the usual pattern for normally related great arteries. Eta-square analysis showed that the evolution from pattern O to IX was dependent on clockwise aortopulmonary rotation. CONCLUSIONS The coronary arteries in complete transposition of the great arteries can be classified into five patterns and their evolution deduced on the basis of aortopulmonary rotation. Dependence of coronary artery type on aortopulmonary rotation made it possible to anticipate the coronary pattern from the relation of the great arteries in transposition.

Long-Term Survival and Unnatural Deaths of Patients With Repaired Tetralogy of Fallot in an Asian Cohort

Background— Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease in Taiwan. This study investigates the long-term survival and risks of TOF in an Asian cohort. Methods and Results— This study enrolled 819 consecutive patients with TOF (61.1% male), who received total correction between 1970 and 2002, as participants. Patient medical records were reviewed, and the survival status of those out of contact was confirmed by death records retrieved from the National Health database. The mean (±SD) patient age at cardiac repair was 6.5±7.6 years, and a prior shunt operation was performed in 119 (14.5%) of the patients. At cardiac repair, a transannular patch for right ventricle outlet reconstruction was required in 444 (54.2%) of the patients. After 13 808 patient-years of follow-up, the 30-year survival rate was 90.5%. The annual mortality rate increased from 0.123% in the initial 15 years after repair to 0.395% thereafter (P<0.05). The presence of major aortopulmonary collateral arteries, older operative age, and previous shunt operation are independent risks of late cardiac deaths. Secondary to cardiac mortality, unnatural deaths (accident and suicide) accounted for 27.6% of late deaths, significantly higher compared with that of the general population (odds ratio, 2.18; P=0.028). Conclusions— In this Asian TOF cohort, except for a late decrease after 15 years, long-term survival after cardiac repair was satisfactory. Although cardiac death was the most common cause of late death, accidents or suicide may also be associated with late mortality, suggesting a potential role for psychosocial support.

Three-dimensional reconstruction of abnormal ventriculoarterial relationship by electron beam CT

PURPOSE Assessment of the relationships of the ventricles and great vessels is critical in evaluating cardiac anomalies before surgery. We investigated the usefulness of 3D CT in their demonstration. METHOD From July 1995 through June 1996, 20 patients with abnormal ventriculoarterial relationships were analyzed by electron beam CT. A 3D gradient shading surface rendering was done on a workstation. We focused on the morphologies of the atria, ventricles, and great vessels and particularly their spatial relationships on the 3D images. RESULTS There were two cases of isolated ventricular inversion, three of anatomically corrected malposition, seven of congenitally corrected transposition, and eight of complete transposition. Anatomic presentations of 3D surface images in all were superior to cineangiography and echocardiography presentations and were consistent with intraoperative findings. CONCLUSION 3D CT images provide useful information that is not available by sectional or projective imaging. Independent segmental analysis of the anomalies by this method provides a complement for surgeons to understand the spatial relationships of the vessels and chambers of the heart, which may be of value in preoperative planning.