Cardiac Operations In Children Research Articles

An Analysis of Hospital Mortality After Cardiac Operations in Children With Down Syndrome

Children with Down syndrome (DS) have lower mortality compared to nonsyndromic (NS) children after atrioventricular septal defect (AVSD) repair. Limited data exist regarding hospital mortality and utilization after other congenital heart disease (CHD) operations in DS. We compared hospital mortality and utilization after CHD operations in both populations and hypothesized that the survival benefit in children with DS is not consistent across CHD lesions. The Texas Inpatient Public Use Datafile was queried for all patients <18 years old undergoing operations for CHD between 1999 and 2016. Hospital mortality, length-of-stay and charges were compared between DS and NS groups, stratified by CHD operation using mixed-effects multivariable analyses and propensity score matching analyses adjusting for prematurity, low birth weight, age, and sex. Over the 18-year period, 2841 cases with DS underwent CHD operations compared to 25,063 NS cases. The most common types of interventions performed in DS were AVSD repair, isolated ventricular septal defect (VSD) repair and tetralogy of Fallot (TOF) repair. By multivariable analyses, DS was associated with lower mortality after isolated AVSD repair (RR 0.40 [IQR 0.20-0.79]), and higher hospital mortality after bidirectional Glenn anastomosis (BDG) (RR 5.17 [IQR 2.10-12.77]) and TOF/pulmonary atresia repair (RR 9.71 [IQR 2.16-43.68]) compared to NS children. Similar results were noted using propensity score matching. Children with DS had lower mortality after AVSD repair than NS children, but higher mortality after operations for BDG and TOF/pulmonary atresia. Further study is needed to determine if the presence of pulmonary hypertension in DS modifies the association between DS and mortality depending on cardiac lesion.

Using Data to Improve Quality: the Pediatric Cardiac Care Consortium.

A program to collect and analyze cardiac catheterization, electrophysiologic studies and cardiac operations in children was initiated in 1982. The purpose was to help centers compare their experience and outcomes with a group of centers to determine areas where their performance might improve. Cardiac centers became members of the Pediatric Cardiac Care Consortium and submitted demographic data and copies of procedure reports regularly to a central office. Data were extracted from the reports, coded by trained coders and entered into a computer database. Annually, the data were analyzed to compare the experience of an individual center with that of the entire group of centers. The annual data were adjusted for severity on the basis of eight factors selected after discussion with participants in the Consortium. Adjustment was by multivariate analysis. Reports were prepared for each center and distributed at an annual meeting. The data were used by centers to review operations where the mortality rate exceeded +2 standard deviations of the group. With discussion, the center staff often initiated changes to improve outcome. The outcome could then be monitored by the annual reports. Our data were also utilized in the creation of the Risk Adjustment for Surgery for Congenital Heart Disease (RACHS)-1 categories of disease severity. The mortality rates of our centers were comparable with the combined hospital discharge data from New York, Massachusetts, and California. From 1982 through 2007, the mortality rates of our centers dropped for each RACHS-1 category, falling to less than 1% for categories 1 and 2 for the last 5-year period. During the 25 years, we received data from 52 centers about 137 654 patients who underwent 117 756 cardiac operations.

Serum Brain Natriuretic Peptide and Risk of Acute Kidney Injury After Cardiac Operations in Children

Acute kidney injury (AKI) after pediatric cardiac operations is associated with poor outcomes and is difficult to predict. We conducted a prospective study to evaluate whether preoperative brain natriuretic peptide (BNP) levels predict postoperative AKI among children undergoing cardiac operations. This was a three-center, prospective study (2007-2009) of 277 children undergoing cardiac operations (n= 121, aged <2 years) with available preoperative BNP values. Preoperative BNP was measured and categorized into tertiles. The performance of BNP was evaluated alone and in combination with clinical factors. AKI was defined as doubling of serum creatinine or need for acute dialysis. Postoperative AKI occurred in 165 children (60%), with 118 cases (43%) being mild and 47 cases (17%) severe. Preoperative BNP was not associated with increased risk of mild or severe postoperative AKI and did not significantly improve AKI risk prediction when added to clinical models. Preoperative BNP was, however, associated with several clinical outcomes, including length of stay and mechanical ventilation. The results were similar when the analysis was repeated in the subset of children younger than 2 years of age or when the association of postoperative BNP and AKI was evaluated. Preoperative BNP levels did not predict postoperative AKI in this cohort of children undergoing cardiac operations. Both preoperative and postoperative BNP levels are associated with postoperative outcomes. Clinical Trial Registration at Clinicaltrials.gov as NCT00774137.

Selective Cerebral Perfusion: Real-Time Evidence of Brain Oxygen and Energy Metabolism Preservation

Deep hypothermic circulatory arrest (DHCA) is commonly used for complex cardiac operations in children, often with selective cerebral perfusion (SCP). Little data exist concerning the real-time effects of DHCA with or without SCP on cerebral metabolism. Our objective was to better define these effects, focusing on brain oxygenation and energy metabolism. Piglets undergoing cardiopulmonary bypass were assigned to either 60 minutes of DHCA at 18 degrees C (n = 9) or DHCA with SCP at 18 degrees C (n = 8), using pH-stat management. SCP was administered at 10 mL/kg/min. A cerebral microdialysis catheter was implanted into the cortex for monitoring of cellular ischemia and energy stores. Cerebral oxygen tension and intracranial pressure also were monitored. After DHCA with or without SCP, animals were recovered for 4 hours off cardiopulmonary bypass. With SCP, brain oxygen tension was preserved in contrast to DHCA alone (p < 0.01). Deep hypothermic circulatory arrest was associated with marked elevations of lactate (p < 0.01), glycerol (p < 0.01), and the lactate to pyruvate ratio (p < 0.001), as well as profound depletion of the energy substrates glucose (p < 0.001) and pyruvate (p < 0.001). These changes persisted well into recovery. With SCP, no significant cerebral microdialysis changes were observed. A strong correlation was demonstrated between cerebral oxygen levels and cerebral microdialysis markers (p < 0.001). Selective cerebral perfusion preserves cerebral oxygenation and attenuates derangements in cerebral metabolism associated with DHCA. Cerebral microdialysis provides real-time metabolic feedback that correlates with changes in brain tissue oxygenation. This model enables further study and refinement of strategies aiming to limit brain injury in children requiring complex cardiac operations.

Effect of modified ultrafiltration on inflammatory mediators, coagulation factors, and other proteins in blood after an extracorporeal circuit.

Modified ultrafiltration (MUF) is a technique able to remove the excess body fluid and inflammatory mediators associated with the use of a cardiopulmonary bypass (CPB). It has been shown to reduce morbidity after cardiac operations in children. Application of MUF after adult cardiac operations has also been suggested being associated with a lower prevalence of early morbidity. However, the relationship between the concentration of mediators in the blood and postoperative morbidity remains yet to be proved. In this study, changes of various chemical mediators in the filtrate and blood before and after MUF have been evaluated in adult patients. Significant reductions of blood levels of inflammatory cytokines were not observed after MUF. On the other hand, MUF significantly elevated hematocrit, number of red cells, concentrations of albumine, coagulation Factor VII and X, platelet factor (PF)-4, and antithrombin (AT-) III.

The clinical implications of the systemic inflammatory reaction related to cardiac operations in children.

The clinical implications of the systemic inflammatory reaction related to cardiac operations in children.

Early postoperative arrhythmias after cardiac operation in children

Background. Arrhythmias are a recognized complication of cardiac operations. However, little is known about the incidence, treatment, and risk factors for early postoperative arrhythmias in children after cardiac operations. Methods. Diagnosis and treatment of early postoperative arrhythmias were prospectively analyzed in an intensive care unit in 100 consecutive children with a median age of 17 months (range, 1 day to 191 months) who had undergone cardiac operation. Patients were grouped in three different categories of surgical complexity. Results. During a median postoperative time of 1 day (range, 0 to 15 days), 64 critical arrhythmias occurred in 48 patients. Arrhythmias consisted of sinus bradycardia in 30, atrioventricular block II to III in 7, supraventricular tachyarrhythmias in 14, and premature complexes in 13 instances. Treatment of 52 arrhythmias was successful and included pacing in 41, intravenous amiodarone in 8, body cooling in 5, overdrive pacing in 3, and electrolyte correction in 2 cases, with more than one treatment modality in 8 cases. Risk factors for arrhythmias were lower body weight ( p < 0.05), longer cardiopulmonary bypass duration ( p < 0.05), and a category of higher surgical complexity ( p < 0.001). Conclusions. Early postoperative arrhythmias occur frequently after cardiac operations in children. Sinus bradycardia, atrioventricular block II to III, and supraventricular tachyarrhythmias are the most frequent arrhythmias, which, however, can be treated effectively by means of temporary pacing, cooling, and antiarrhythmic drug therapy. Lower body weight, longer cardiopulmonary bypass duration, and a higher surgical complexity are risk factors for early postoperative arrhythmias.

Octreotide to treat postoperative chylothorax after cardiac operations in children

Chylothorax after pediatric cardiac operations is associated with significant morbidity and increased hospitalization. An octreotide (a synthetic somatostatin analogue) infusion (1 to 4 μg/kg per hour) with medium-chain triglyceride diet or parenteral nutrition was used in 4 pediatric cardiac surgical patients after chylothorax was diagnosed. Resolution followed within 5 days in all without recurrence, while on a normal diet.

Modified Ultrafiltration Reduces Morbidity After Adult Cardiac Operations

Background Extracorporeal circulation contributes to morbidity after open-heart surgery by causing a systemic inflammatory reaction. Modified ultrafiltration is a technique able to remove the fluid overload and inflammatory mediators associated with use of cardiopulmonary bypass. It has been shown to reduce morbidity after cardiac operations in children, but the impact on adult cardiac procedures is unknown. Methods and Results Five hundred seventy-three consecutive adult patients were prospectively randomized to either ultrafiltration after cardiopulmonary bypass (treatment) or to no ultrafiltration (control). Parsonnet score was used to assess the severity of the patients’ clinical conditions. Analysis was done with Student’s t test or Mann-Whitney U test for continuous variables and Fisher’s exact test or Pearson’s χ 2 for discrete variables. Hospital mortality was 2.5% (7 of 284) in the treatment group versus 3.8% (11 of 289) in the control group ( P =0.357). Hospital morbidity was lower in treated patients (66 of 284 [23.2%] versus 117 of 289 [40.5%], P =0.0001). Cardiac morbidity was similar (26 of 284 [9.1%] versus 35 of 289 [12.1%], P =0.251), whereas significantly lower rates of respiratory (20 of 284 [7.0%] versus 36 of 289 [12.5%], P =0.029), neurological (5 of 284 [1.8%] versus 14 of 289 [4.8%], P =0.039), and gastrointestinal (0 of 284 versus 4 of 289 [1.4%], P =0.044) complications were found in treated patients. Transfusion requirements were also lower in treated patients (1.66±2.6 versus 2.25±3.8 U/patient, P =0.039). Duration of intensive care (39.9±49.2 versus 46.3±72.8 hours, P =0.218) and hospital stay (7.6±3.5 versus 7.9±4.4 days, P =0.372) were comparable. Conclusions Modified ultrafiltration after cardiopulmonary bypass is associated with a lower prevalence of early morbidity and lower blood transfusion requirements. The impact on length of hospital stay needs further analysis. Routine application of modified ultrafiltration after adult cardiac operations is warranted.

Chylopericardium after cardiac operations in children

Background. Chylopericardium is a rare complication after operation for congenital heart disease. The incidence and clinical outcomes in a large cohort of surgical patients are unknown. Methods. We retrospectively reviewed the clinical records spanning more than 12 years in a single institution of 16 children with chylopericardium after cardiac operation. Results. We identified 16 patients with chylopericardium between 1985 and 1997. Chylopericardium was isolated in 7 patients. Twelve patients required pericardial drainage. Patients with isolated chylopericardium presented late and were treated initially as having postpericardiotomy syndrome. Three patients underwent thoracic duct ligation. There were two late deaths unrelated to the chylothorax. Associated diagnoses were internal jugular vein thrombosis and recurrent pulmonary vein obstruction (1 of 16 patients), an associated syndrome but not Turner or Noonan (10 of 16), superior cavopulmonary or total cavopulmonary anastomosis (7 of 16), atrioventricular septal defect repair (5 of 16), and repair of tetralogy of Fallot (2 of 16). Conclusions. Percutaneous drainage to relieve tamponade together with a low-fat or medium-chain triglyceride diet results in resolution in most cases of postoperative chylopericardium. If a pericardial effusion enlarges, fails to clear on aspirin therapy, or presents late after hospital discharge, diagnostic pericardial tap and a low-fat diet are indicated.

Preoperative autologous donation of blood for a simple cardiac anomaly: Analysis of children weighing under twenty kilograms

Objective: Preoperative autologous donation of blood has been expanded to cardiac operations in children. However, because of problems such as lack of cooperation and hemodilution during cardiopulmonary bypass, its efficacy in small children is unclear. This study clarifies the clinical significance of preoperative autologous donation of blood in small children. Methods: Thirty-seven patients weighing under 20 kg (age range, 3-9 years; weight range, 13-20 kg) underwent preoperative autologous donation and cardiac operations to treat a simple anomaly. Twenty-five age- and weight-matched patients who were not cooperative or refused preoperative autologous donation served as control subjects. Autologous blood was collected by the simple or leapfrog method and stored as blood components. Each collecting volume was 5 to 10 mL/kg. Results: The donation was performed 6 ± 2 times during 50 ± 16 days, and the whole storage volume was 48 ± 17 mL/kg. There was no serious complication. The minimum hematocrit level negatively correlated with the priming volume of cardiopulmonary bypass (preoperative donation patients: P < .01, r2 = 0.4; control subjects: P = .5, r2 = 0.03). Blood loss did not significantly differ between preoperative donation patients and control subjects, and the transfused blood volumes were 43 ± 13 mL/kg and 29 ± 22 mL/kg, respectively. All of the autologous blood products but fresh frozen plasma were reinfused. Use of homologous blood was significantly less in preoperative donation patients than in control subjects (0% vs 80%, P < .01). In preoperative donation patients postoperative recovery in hemoglobin level was significantly better, which is concurrent with a higher reticulocyte level. Conclusion: Preoperative autologous donation can be performed safely with clinical efficacy, even in children under 20 kg. This can be improved further through coupling with another procedure. (J Thorac Cardiovasc Surg 2000;120:783-9)

Commentary

Commentary

Cardiac Operations in Children With Marfan’s Syndrome: Indications and Results

Background. The development of new screening techniques for the early detection of Marfan’s syndrome has prompted evaluation of the results of cardiac operations in children with this syndrome. The purpose of this study was to determine the surgical indications, operative results, and need for reoperation in children with Marfan’s syndrome. Methods. From 1980 to 1996, 245 patients underwent cardiac operations for complications of Marfan’s syndrome; 26 (11%) were less than 18 years of age. The mean age at the time of operation was 10.3 ± 1 years (range, 8 months to 17 years); 18 of the patients were male. Indications for operation were aortic root dilatation (15 patients), mitral regurgitation (4 patients), aortic root dilatation and mitral regurgitation (6 patients), and aortic arch aneurysm (1 patient). Operations included aortic root replacement (15 patients), aortic root replacement and mitral repair (5 patients), aortic root replacement and mitral replacement (1 patient), mitral repair (3 patients), mitral replacement (1 patient), and arch aneurysm repair (1 patient). The mean aortic root diameter in patients undergoing aortic root replacement was 6.2 ± 0.2 cm. Only 1 patient underwent ascending aortic dissection. Results. There were no operative deaths. At a mean follow-up of 67.1 ± 10.2 months, 8 patients required a second cardiac procedure (41% ± 17% 10-year freedom from reoperation). Indications for further operations were distal aortic pathology (3 patients), aortic root dilatation after initial mitral operation (3 patients), failed mitral repair (1 patient), and homograft degeneration (1 patient). Risk factors for a second cardiac procedure were age less than 10 years at the time of the first operation ( p < 0.003) and mitral regurgitation ( p < 0.04). Overall, 25 (96%) of 26 patients have undergone aortic root replacement and 11 (42%) patients have undergone a mitral procedure. There have been 4 late deaths, all of presumed cardiac origin. The 10-year survival rate is 79% ± 10%. All surviving patients are in New York Heart Association functional class I or II. Conclusions. We conclude that (1) aortic root dilatation is the most common surgical indication in children with Marfan’s syndrome, (2) mitral regurgitation is the second most common indication, (3) aortic dissection is unusual in children with Marfan’s syndrome, and (4) careful follow-up is necessary, particularly in younger children, because more than half of all children with Marfan’s syndrome require repeated cardiac operations within 10 years.

Central venous thrombosis after cardiac operations in children: J. Petaja, U. Lundstrom, H. Sairanen, et al. J Thorac Cardiovasc Surg 112:883–889, (October), 1996

Central venous thrombosis after cardiac operations in children: J. Petaja, U. Lundstrom, H. Sairanen, et al. J Thorac Cardiovasc Surg 112:883–889, (October), 1996

Central venous thrombosis after cardiac operations in children

To evaluate the incidence, mortality, late outcome, and cause of central venous thrombosis after pediatric heart operations and other operations performed with cardiopulmonary bypass, we identified patients with postoperative central venous thrombosis during a 10-year period at a single pediatric hospital. There had been 1591 open heart (with bypass) and 1086 closed heart (no bypass) procedures and 13 operations with cardiopulmonary bypass for extracardiac indications. There were 20 patients with central venous thrombosis, yielding incidences of 1.1% and 0.2% after cardiopulmonary bypass and after closed heart operations, respectively. When neonates were compared with older children (1 to 119 months of age) undergoing heart procedures, a tenfold increase (5.8% vs 0.6%) ( p < 0.001) in the incidence of central venous thrombosis was observed. The mortality was eight of 20 (40%). Central venous thrombosis contributed to seven deaths and it was a direct cause of one death. Ten patients were reinvestigated 5 to 108 months after central venous thrombosis. The outcome of surgery was excellent in eight. Two had residual thrombosis, but this was not hemodynamically significant to the cardiorespiratory condition of the patients. During or preceding thrombosis, low levels of antithrombin III and/or protein C and high levels of the plasminogen activator inhibitor were observed in five of the patients. A congenital thrombotic risk factor, "resistance to activated protein C," was found in two of 12 tested patients with central venous thrombosis (17%). In conclusion, central venous thrombosis, especially in neonates, is an important cause of morbidity and mortality after cardiac operations. The cause is multifactorial, with contributions from multiple acquired thrombophilic coagulation abnormalities, and resistance to activated protein C may act as a risk factor for thrombosis already during neonatal period. (J T HORAC C ARDIOVASC S URG 1996;112:883-9)

The effect of preoperative tranexamic acid on blood loss after cardiac operations in children

Children undergoing cardiac operations in which cardiopulmonary bypass is used are at risk of significant postoperative blood loss. The acquired coagulopathy is complex but is thought to be due, in part, to excessive fibrinolysis. We examined the possibility of reducing postoperative blood loss in children by using the antifibrinolytic drug tranexamic acid. Using a prospective, randomized, double-blind study design, we administered a single dose of tranexamic acid (50 mg/kg intravenously) or saline placebo, before skin incision, in 88 children undergoing cardiac operations. Postoperative blood loss and fluid replacement were recorded for the next 24 hours. In addition, hemoglobin, platelet counts, and coagulation measures were recorded every 6 hours. When all patients were examined, there was no significant difference in postoperative blood loss between the treated and placebo groups (21.2 ± 12 ml/kg per 24 hours, tranexamic acid, vs 27.2 ± 20.3 mls/kg per 24 hours, placebo). However, when the children with cyanosis were analyzed separately, there was a highly significant difference in blood loss between the groups during the first 6 hours (11.2 ± 3.7 ml/kg per 6 hours, tranexamic acid, vs 27.2 ± 11.4 mls/kg per 6 hours, placebo; p < 0.002), as well as the overall 24 hour study period (23.7 ± 7.5 mls/kg per 24 hours, tranexamic acid, vs 48.9 ± 27.6 mls/kg per 24 hours, placebo; p < 0.02). Also significantly less blood and blood products were administered to the treated cyanosed group. Tranexamic acid produced a significant reduction in postoperative blood loss and blood product requirements in children with cyanosis undergoing heart operations. The drug had no effect in children without cyanosis or those requiring a second thoracotomy. (J T HORAC C ARDIOVASC S URG 1996;111:982-7)

The relationship between intelligence and duration of circulatory arrest with deep hypothermia

A total of 114 children (51 with tetralogy of Fallot, 30 with transposition of the great arteries, and 33 with ventricular septal defect) who had these defects repaired with the use of deep hypothermia and circulatory arrest were assessed for intellectual and neuropsychologic function at an average of 9 to 10 years after the operation. Children with preoperative intellectual handicaps or postoperative neurologic complications were excluded. These children were compared with 54 who had atrial septal defects repaired with the use of cardiopulmonary bypass. The only significant difference in the neuropsychologic measures was that the bypass group had reaction times 2 to 3 seconds shorter on average than those of the hypothermic circulatory arrest group. Although there was no significant difference in intelligence quotient between the groups, a relationship between intelligence quotient and arrest time was found. Regression analysis of intelligence quotient against duration of arrest showed a significant decrease in intelligence quotient with increasing arrest time (slope = -0.36; p = 0.002; 95% confidence interval, -0.59, -0.14) indicating a decrease of 3 to 4 intelligence quotient points for each extra 10 minutes of arrest time. It appears that deep hypothermia with circulatory arrest for cardiac operations in children does not fully protect the brain, with a linear relationship existing between the amount of impairment and the duration of circulatory arrest. (J T HORAC C ARDIOVASC S URG 1995;110:786-92)

The effect of desmopressin acetate (DDAVP) on postoperative blood loss after cardiac operations in children

We investigated the effect of an intraoperative desmopressin acetate infusion on blood loss after cardiac operation in 60 children, by using a prospective, randomized, double-blind trial. Thirty patients received a desmopressin dose of 0.3 microgram/kg intravenously over 15 minutes at the conclusion of cardiac bypass, and 30 received a saline placebo. The two groups were comparable with respect to age, sex, cardiac lesion, presence of cyanosis, and prevalence of Down's syndrome. Results showed no significant difference in postoperative blood loss between the two groups (30.5 +/- 37.9 ml/kg in the placebo group versus 40.0 +/- 33.1 ml/kg in the desmopressin group). Postoperative bleeding time, total urine output, postinfusion hemodynamics, and postoperative coagulation studies did not differ significantly between the two groups. We conclude that postbypass desmopressin infusion does not reduce blood loss in children undergoing cardiac operations.

A Prospective Randomized Study of Membrane versus Bubble Oxygenators in Children

We studied 60 children, 2 weeks to 10 years old, prospectively by randomly assigning them to a SciMed membrane oxygenator or Harvey bubble oxygenator. Variables of cardiopulmonary bypass (CPB) were closely controlled: prime, circuit configuration, flow rate, and blood gases. Blood variables measured at eight intervals before, during, and after operation were as follows: seven plasma proteins, free hemoglobin, formed elements, and clotting functions. Preoperatively and postoperatively, we evaluated brain function (psychological testing), renal function (creatinine clearance), and pulmonary function (compliance changes and postoperative shunt fraction). Postoperative blood loss, fever, and length of hospitalization were also evaluated. We compared 302 variables by computer program. No difference ( p > 0.05) between the two groups was found in any variable related to CPB or organ function (pulmonary, renal, or cerebral) or in hematological variables except free hemoglobin. After 5 and 60 minutes of CPB and the next day, it was significantly lower ( p < 0.05) in the group with a membrane oxygenator. Safety, cost, and convenience, not physiology, should be the major factors in considering membrane versus bubble oxygenators for cardiac operations in children.