Surgical Quality Predicts Length of Stay in Patients with Congenital Heart Disease.

Historically, the primary marker of quality for congenital cardiac surgery has been postoperative mortality. The purpose of this study was to determine whether additional markers (10 surgical metrics) independently predict length of stay (LOS), thereby providing specific targets for quality improvement. Ten metrics (unplanned ECMO, unplanned cardiac catheterization, revision of primary repair, delayed closure, mediastinitis, reexploration for bleeding, complete heart block, vocal cord paralysis, diaphragm paralysis, and change in preoperative diagnosis) were defined in 2008 and subsequently collected from 1024 consecutive index congenital cardiac cases, yielding 990 cases. Four patient characteristics and 22 case characteristics were used for risk adjustment. Univariate and multivariable analyses were used to determine independent associations between each metric and postoperative LOS. Increased LOS was independently associated with revision of the primary repair (p = 0.014), postoperative complete heart block requiring a permanent pacemaker (p = 0.001), diaphragm paralysis requiring plication (p < 0.001), and unplanned postoperative cardiac catheterization (p < 0.001). Compared with patients without each metric, LOS was 1.6 (95 % CI 1.1-2.2, p = 0.014), 1.7 (95 % CI 1.2-2.3, p = 0.001), 1.8 (95 % CI 1.4-2.3, p < 0.001), and 2.0 (95 % CI 1.7-2.4, p < 0.001) times as long, respectively. These effects equated to an additional 4.5-7.8 days in hospital, depending on the metric. The other 6 metrics were not independently associated with increased LOS. The quality of surgery during repair of congenital heart disease affects outcomes. Reducing the incidence of these 4 specific surgical metrics may significantly decrease LOS in this population.

Abnormal myocardial blood flow in children with mild/moderate aortic stenosis.

OBJECTIVE: To quantify myocardial blood flow in infants and children with mild or moderate aortic stenosis using adenosine-infusion cardiac magnetic resonance. BACKGROUND: It is unclear whether asymptomatic children with mild/moderate aortic stenosis have myocardial abnormalities. In addition, cardiac magnetic resonance-determined normative myocardial blood flow data in children have not been reported. METHODS: We studied 31 infants and children with either haemodynamically normal hearts (n=20, controls) or mild/moderate aortic stenosis (n=11). The left ventricular myocardium was divided into six segments, and the change in average segmental signal intensity during contrast transit was used to quantify absolute flow (ml/g/minute) at rest and during adenosine infusion by deconvolution of the tissue curves with the arterial input of contrast. RESULTS: In all the cases, adenosine was well tolerated without complications. The mean pressure gradient between the left ventricle and the ascending aorta was higher in the aortic stenosis group compared with controls (24 versus 3 mmHg, p<0.001). Left ventricular wall mass was slightly higher in the aortic stenosis group compared with controls (65 versus 50 g/m², p<0.05). After adenosine treatment, both the absolute increase in myocardial blood flow (p<0.0001) and the hyperaemic flow significantly decreased (p<0.001) in children with mild/moderate aortic stenosis compared with controls. CONCLUSION: Abnormal myocardial blood flow in children with mild/moderate aortic stenosis may be an important therapeutic target.

Fetal ventricular interactions and wall mechanics during ductus arteriosus occlusion in a sheep model.

We investigated the effect of fetal sheep ductus arteriosus occlusion (DO) on the distribution of cardiac output and left and right ventricular function by tissue and pulsed Doppler at baseline; after 15 and 60 min of DO induced with a vascular occluder; and 15 min after release of DO. Ductal occlusion decreased fetal pO2. Mean left ventricular output increased (p < 0.001) from 725 to 1013 mL/min, and right ventricular (1185 mL/min vs. 552 mL/min) and systemic (1757 mL/min vs. 1013 mL/min) cardiac outputs fell (p < 0.001) after 15 min of DO, compared with baseline. Pulmonary vascular impedance decreased and volume blood flow increased more than threefold during DO, whereas foramen ovale volume blood flow remained unchanged. Left ventricular systolic function was unaffected, whereas isovolumic relaxation velocity deceleration decreased. Right ventricular functional indices remained unchanged. We conclude that DO increased pulmonary volume blood flow, not foramen ovale volume blood flow. Left ventricular output increased, although not as much as right ventricular output fell, resulting in decreased systemic cardiac output. During DO, left ventricular function exhibited diminished relaxation.

High flow velocity through congenital cardiac lesions predicts preoperative platelet dysfunction.

BACKGROUND: Platelet dysfunction resulting from abnormal fluid shear stress has been reported in adults with aortic stenosis. Blood flowing through a congenital heart defect at greater than normal velocity is subjected to increased shear stress. The primary aim was to determine whether peak flow velocity through congenital cardiac lesions predicts preoperative platelet dysfunction. METHODS: The charts of 402 patients who underwent cardiopulmonary bypass and had preoperative platelet function analysis were evaluated. Platelet dysfunction was measured as a prolonged closure time (CT) in seconds with a platelet function analyzer. Echocardiography was used to determine peak velocity. The relationship between peak velocity and CT was analyzed using linear regression and Kaplan-Meier estimation. RESULTS: The distribution of peak velocity was bimodal. The mean velocity of the lower group was 1.9 m/second and the higher group was 4.2 m/second. Univariate analysis showed age, weight, peak velocity, hematocrit, and Risk Adjustment for Congenital Heart Surgery score to be associated with prolonged CT. Using multivariable analysis, prolonged CT was significantly associated with peak velocity (p < 0.001). For each 1m/second increase in peak velocity the CT increased by over 9 seconds (p < 0.001). In addition, a median CT increase of more than 6 seconds was also associated with a 5 percentage point drop in hematocrit (p = 0.04). CONCLUSIONS: Platelet dysfunction is associated with high blood flow velocity through congenital cardiac lesions. Lower preoperative hematocrit was associated with prolonged CT, which may suggest subclinical bleeding secondary to platelet dysfunction.

A defined management strategy improves early outcomes after the Fontan procedure: the PORTLAND protocol.

BACKGROUND: Patients undergoing the Fontan procedure may have extended hospital stay due to various postoperative factors including prolonged chest tube drainage. Our aim was to determine the efficacy of our Fontan management protocol in reducing chest tube drainage and length of stay. METHODS: Patients who underwent a Fontan procedure at our institution from June 2008 to September 2013 were analyzed (n = 42). We currently manage our patients according to the PORTLAND protocol: Peripheral vasodilation, Oxygen, Restriction of fluids, Technique of surgery, Low-fat diet, Anticoagulation (including antithrombin III management), No ventilator, and Diuretics. Group A (n = 28) had surgery prior to initiation of this protocol; group B (n = 14) had surgery during the current protocol era. RESULTS: The median number of chest tube days was lower in group B (6 vs 11 days, p < 0.001) as was the total indexed drainage (126 vs 259 mL/kg, p < 0.001). Patients in group B had shorter intensive care unit length of stay (4 vs 7 days, p = 0.004) and hospital length of stay (8 vs 13 days, p = 0.001). Group B had higher preoperative common atrial pressures (7.0 vs 5.8 mm Hg, p = 0.017), end-diastolic pressures (9 vs 7 mm Hg, p = 0.026), and trended toward higher pulmonary artery pressures (11.5 vs 9.5 mm Hg, p = 0.077). There was no statistically significant difference in age, weight, transpulmonary gradient, or pulmonary vascular resistance between groups. CONCLUSIONS: The PORTLAND protocol has improved early outcomes after the Fontan procedure. Chest tube drainage and duration, and both intensive care unit and hospital length of stay have been reduced since initiation of this protocol.

Preoperative platelet dysfunction predicts blood product transfusion in children undergoing cardiac surgery.

OBJECTIVES: Excessive bleeding can be a problem during or after cardiac surgery. While cardiopulmonary bypass-associated platelet dysfunction is an important inducer of coagulopathy, preoperative platelet dysfunction can also contribute to this bleeding. We investigated the relationship between preoperative platelet dysfunction and transfusion of blood products given to children undergoing cardiac surgery. METHODS: The platelet function analyser test measures platelet function in vitro by aspirating blood through a small standard hole (creating high shear) in a collagen membrane infused with a platelet agonist. The time taken to form a platelet plug is known as closure time and prolonged closure time (CT) indicates platelet dysfunction. Three hundred and thirty-eight children who had undergone surgery with cardiopulmonary bypass between 2008 and 2012 were included. The volume of red blood cells and fresh-frozen plasma transfused was recorded. The relationship between closure time and transfusion requirements was analysed using linear and logistic regression. RESULTS: Patients with prolonged closure time had greater odds of getting red blood cells and fresh-frozen plasma transfusions compared with patients with normal closure time (P <0.01). On univariate analysis, age, weight, haematocrit, cardiopulmonary bypass time, Risk Adjustment for Congenital Heart Surgery score and closure time were associated with increased odds of red blood cells and fresh-frozen plasma transfusion in the operation theatre (P <0.05). However, when logistic multivariable regression analysis was applied, only age, cardiopulmonary bypass time and closure time remained as significant predictive factors for transfusion. CONCLUSIONS: In children who have undergone cardiac surgery, when age and cardiopulmonary bypass time are accounted for, a prolonged preoperative closure time is significantly associated with increased odds of red blood cells and fresh-frozen plasma transfusion in the operation theatre. This may have implications for planning and utilization of blood products.

Causes of readmission after operation for congenital heart disease.

BACKGROUND: Readmission after operations for congenital heart conditions has significant implications for patient care. Readmission rates vary between 8.7% and 15%. The aim of this study was to determine the incidence, causes, and risk factors associated with readmission. METHODS: 811 consecutive patients undergoing operations for congenital heart conditions were analyzed. Readmission was defined as admission to any hospital within 30 days of discharge for any cause. Demographic, preoperative, operative, and postoperative variables were evaluated. Univariate comparisons were made between the nonreadmission and readmission groups, and multivariate logistic regression analysis was made to determine independent risk factors for readmission. RESULTS: There were a total of 92 readmissions in 79 patients (9.7%). The reasons included cardiac (36, 39%), pulmonary (20, 22%), gastrointestinal (13, 14%), infectious (20, 22%), and other adverse events (2, 2%). Patients with either single-ventricle palliation or nasogastric feeding accounted for 40 (50%) readmissions. On univariate analysis, there were significant differences between readmitted and nonreadmitted patients in relation to patient age, chromosomal abnormality, mortality risk score, duration of mechanical ventilation, postoperative length of stay, single-ventricle physiology, and nasogastric feeding at discharge (p < 0.05). On multivariate analysis, significant risk factors for readmission were single-ventricle physiology (odds ratio [OR] 2.39; 95% confidence interval [CI] 1.28 to 4.47; p=0.005), preoperative arrhythmia (OR 2.59; 95% CI 1.02 to 6.59; p=0.04), longer postoperative length of stay (OR 2.2; 95% CI 1.22 to 3.99; p=0.008), and nasogastric tube feeding at discharge (OR 2.2; 95% CI 1.15 to 4.19; p=0.01). CONCLUSIONS: The incidence of readmission after operations for congenital cardiac conditions remains high. Efforts focusing on patients with single-ventricle palliation and those with preoperative arrhythmia, prolonged postoperative length of stay and nasogastric tube feeding at discharge may be particularly beneficial.

Congenital cardiac lesions involving systolic flow abnormalities are associated with platelet dysfunction in children.

BACKGROUND: Shear stress-induced platelet dysfunction (PD) is prevalent among adults with aortic stenosis. Our aim was to determine whether abnormal platelet function was associated with specific congenital cardiac lesions in children. METHODS: The charts of 407 children who had undergone cardiopulmonary bypass and had preoperative platelet function analysis were evaluated. Patients were assigned to 1 of 11 different lesion categories. Platelet dysfunction (PD) was defined as prolonged closure time (CT) as measured with a platelet function analyzer. Odds ratio (OR) estimates for prolonged CT were calculated for each lesion category. Mean CTs were compared with Tukey-Kramer separated means testing. Analysis of variance modeling was used to determine association between hematocrit value and CT. RESULTS: CT in patients with ventricular septal defects (VSD) and right ventricular outflow tract obstruction (RVOTO) lesions was prolonged. OR analysis found that patients with VSDs (OR, 2.46) or RVOTO (OR, 2.88) had at least a 95% probability of an abnormal CT. In contrast, patients with atrial septal defect (ASD), bidirectional Glenn procedure (BDG), and pulmonary insufficiency (PI) had a reduced probability of a prolonged CT (p < 0.05). A similar pattern was seen in parametric analysis comparing mean CTs across lesion categories. A lower preoperative hematocrit value was associated with prolonged CTs across all lesion types (p < 0.05). CONCLUSIONS: PD was common in children with congenital cardiac lesions involving systolic flow abnormalities and was uncommon among children with lesions having diastolic abnormalities. Lower preoperative hematocrit values were associated with prolonged CTs, suggesting subclinical bleeding secondary to excessive platelet shearing.

Are children undergoing cardiac surgery receiving antibiotics at subtherapeutic levels?

OBJECTIVES: Perioperative antibiotics have decreased-but not eradicated-postoperative infections. In patients undergoing cardiac surgery with cardiopulmonary bypass, the dilutional effect of the priming and any additional volume given during the procedure may lead to subtherapeutic antibiotic levels. Our aim was to determine if children undergoing cardiac surgery with cardiopulmonary bypass receive perioperative antibiotics at subtherapeutic levels. METHODS: Using published pharmacokinetic data on cefuroxime, we developed a computer simulation model to generate a nomogram predicting patients at risk for subtherapeutic cefuroxime levels based on time from initial dosing and additional volume given. RESULTS: A computer-generated 1-compartment pharmacokinetic model was created to predict cefuroxime plasma levels over time for patients of all weights and additional volumes given for both a 25- and 50-mg/kg intravenous dose. For example, following a 25-mg/kg dose, a patient receiving an additional volume of 275 mL/kg is predicted to be subtherapeutic (<16 mg/L=4×minimum inhibitory concentration) at 4 hours. Our nomogram predicts all patients will be subtherapeutic at 8 hours, consistent with general pediatrics dosing schemes. Following a 50-mg/kg dose, levels are predicted to be subtherapeutic after an additional volume of 315 mL/kg at 5.5 hours. CONCLUSIONS: Our model predicts which patients undergoing cardiac surgery with cardiopulmonary will have subtherapeutic cefuroxime levels. This nomogram enables providers to determine when to administer additional antibiotics in patients receiving large additional volumes during cardiac surgeries. This rational approach to perioperative antibiotic dosing may result in a reduction in postoperative infection in this vulnerable patient population.

Adjustment of the surgical plan in repair of congenital heart disease: the power of cross-sectional imaging and three-dimensional visualization.

The purpose of this article is to study the importance of cross-sectional imaging in preoperative evaluation and surgical planning. Echocardiography is the modality of choice to diagnose cardiac diseases. However, in some cases, the data obtained from echocardiogram are insufficient or the image quality is poor. In these cases, additional modalities are being used to provide further information that can aid in guiding medical management of or surgical planning for the patient. Cross-sectional imaging has become widely available in many institutions. These imaging techniques, especially with three-dimensional reconstructions, provide realistic images that have imperative diagnostic values. Moreover, the possibility of sophisticated image-processing techniques provides important hemodynamic characteristics via less invasive methods. In this article, we present three cases in which additional cross-sectional imaging seemed to be a crucial step prior to surgical planning.

The neonatal hypoplastic aortic arch: decisions and more decisions.

Neonatal patients with hypoplasia of the aortic arch constitute a heterogeneous group with a wide spectrum of severity. The milder end of the spectrum comprises patients with aortic coarctation and isthmus hypoplasia. At the other end of the spectrum are patients with severe transverse arch hypoplasia or hypoplastic left heart syndrome. The aim of this paper is to discuss the various strategies and surgical approaches available for this group of patients, focusing on the surgical decisions that influence individual patient management. Many of the things discussed are applicable to any neonatal arch problem. We also describe and discuss in detail our surgical technique for patients who undergo neonatal repair of a hypoplastic aortic arch via median sternotomy.

First case of intracardiac foregut cyst occurring in the left-ventricular outflow tract.

An 11 day-old female infant underwent resection of a mass in the subaortic region secondary to critical aortic stenosis. At 3 months of age, recurrent severe left-ventricular outflow obstruction (LVOT) in the setting of heart failure prompted redo surgery, and the resected mass revealed an intracardiac foregut cyst, which is a rare finding. To our knowledge, this is the first case describing obstruction of the LVOT.

Hypoplastic right cervical aortic arch.

We describe a neonate with a rare congenital anomaly of the aorta. The anomaly included a hypoplastic aortic arch that was cervical and right sided. This complex combination was treated by a Norwood type procedure reconstructing a right-sided arch and, in a later stage, a Rastelli procedure. These 2 procedures achieved a 2 ventricular repair. The diagnostic and surgical challenges of this rare anomaly are described in this case report.

A child with eosinophilia, Loeffler endocarditis, and acute lymphoblastic leukemia.

We present an 8-year-old male with Loeffler endocarditis and acute lymphoblastic leukemia with hypereosinophilia (ALL/Eo) who initially presented with a 3-month history of peripheral eosinophilia thought to be due to visceral larval migrans. Despite treatment for Toxocara, his leukocytosis persisted and he developed mitral valve insufficiency and congestive heart failure. Myocardial biopsy revealed fibrosis and thrombus formation indicative of Loeffler endocarditis, and a peripheral smear showed pre-B-cell acute lymphoid leukemia. This unique case highlights a rare, yet serious sequella of prolonged eosinophilia.

Successful surgical correction of total anomalous pulmonary venous drainage in the sixth decade.

We report an unusual case of total anomalous pulmonary venous drainage (TAPVD), who was successfully treated by surgery at the age of 56 years. We believe that this is the oldest person in the English literature to undergo surgical correction of TAPVD. The pathophysiology and factors for prolonged survival are further discussed.

Aortic valve replacement in a young patient with essential thrombocytosis.

Essential Thrombocythcythaemia (ET) is an uncommon type of myeloproliferative disorder, characterised by both thrombotic and haemorrhagic diathesis. No clear guidelines exist for the pre- and post-operative management of patients undergoing cardiac surgery in the haematological and surgical literature. This condition has profound implications in patients undergoing cardiac surgery with the use of cardiopulmonary bypass, where heparin is used for anti-coagulation. This dilemma is further compounded in the setting of a young patient undergoing aortic valve replacement (AVR), where insertion of a mechanical prosthesis would be the procedure of choice. This would require life-long anticoagulation with warfarin which can predispose these patients to catastrophic bleeding. Using a tissue valve will subject the patient to multiple redo operations in the patient's lifetime. We report a young patient with ET requiring AVR and discuss the dilemmas surrounding the choice of prosthesis in this patient.

Subcoronary allograft aortic valve replacement: parametric risk-hazard outcome analysis to a minimum of 20 years.

BACKGROUND: Differences in sterilization, preservation, and implantation have been implicated in aortic allograft longevity. We report follow-up to 30 years of patients from a single unit who underwent aortic valve replacement with aortic allografts sterilized in antibiotics and refrigerated at 4 degrees C. METHODS: Two hundred consecutive patients underwent subcoronary allograft aortic valve replacement and have been followed up to a minimum of 20 and maximum of 30 years. Follow-up was 96% complete. Parametric hazard phase modeling was used to identify incremental predictors of time-related risk. RESULTS: Early mortality was 1.5%. Kaplan-Meier actuarial survival, including early death, was 81.2% +/- 2.8% (mean +/- standard error of the mean), 58.0% +/- 3.7%, and 52% +/- 5.1% at 10, 20, and 25 years, respectively. Freedom from reoperation for any reason was 86.4% +/- 2.6%, 39.6% +/- 5.2%, and 35.0% +/- 5.4% at 10, 20, and 25 years, respectively. Larger implanted valve, reexploration for bleeding, previous cardiac surgery, and operative rank were independent risks for reoperation. Early mortality in reoperations was 5.1%. Allograft endocarditis has occurred in 6 patients, giving an overall freedom of 94% at 25 years. Seven patients of the original cohort are known to be alive with their original allograft valve in situ, and of these the longest follow-up period is 29.8 years. CONCLUSIONS: The use of antibiotic-sterilized allografts for subcoronary aortic valve replacement confers low operative mortality and excellent long-term survival with durability matching any other nonmechanical device. Significantly reduced time-related risk of reoperation and excellent internal to external diameter ratio renders allograft aortic valve replacement especially ideal for smaller roots.

Endovascular clamping of porcelain aorta in aortic valve surgery using Foley Catheter.

Unclampable calcified aorta is an uncommon condition that all cardiac surgeons may encounter and performing aortic valve surgery in this condition with a non cross-clamping technique of using Foley Catheter has rarely been reported. Aortic valve surgery invariably becomes a high-risk, challenging procedure to cardiac surgeon or even a contraindication to surgery when the ascending aorta cannot be clamped due to extensive calcification precluding safe dissection and clamping. We describe and recommend a non cross-clamping technique of using Foley Catheter and report it successful use in two patients who underwent aortic valve replacement with "porcelain" unclampable aorta.