Christopher W. Baird

The relative validity of actuarial- and consensus-based risk assessment systems

Abstract In an effort to improve decision-making in child protective services (CPS), most states have, over the last two decades, implemented risk assessment systems to guide staff faced with making critical decisions in limited time frames. Generally, these systems are characterized as consensus-based or actuarial models. This study is the first to directly compare the relative validity of these two approaches. Three risk assessment instruments, two consensus-based and one actuarial, were completed on cohorts of cases from four different jurisdictions and outcome information was collected over an 18-month follow-up period. Rates of subsequent investigations, substantiations, and placements were computed for cases classified at low, moderate, and high risk levels in each model. Results clearly demonstrate that the actuarial approach more accurately classifies cases to different risk levels. These actuarial models, therefore, have the greatest potential to improve CPS decision making and better protect Americas at risk children.

Accelerated Degeneration of a Bovine Pericardial Bioprosthetic Aortic Valve in Children and Young Adults

Background— Experience with aortic valve replacement (AVR) with current-generation pericardial bioprostheses in young patients is limited. The death of a child with accelerated bioprosthetic aortic stenosis prompted enhanced surveillance of all such patients at our institution. Methods and Results— We reviewed records of 27 patients who had undergone AVR (median follow-up, 13.7 months) with a bovine pericardial bioprosthesis at ⩽30 years of age. In the Mitroflow LXA valve group (n=15), freedom from valve failure was 100% at 1 year, 53% (95% confidence interval, 12–82) at 2 years, and 18% (95% confidence interval, 1–53) at 3 years. No Magna/Magna Ease valves (n=12) failed by 3 years. Among valve failure patients, median age at AVR was 12 years (range, 10–21 years). Life-threatening prosthetic aortic stenosis was detected at a median of 6 months after prior echocardiograms showing mild or less gradients. Patients with Mitroflow LXA compared with Magna/Magna Ease valves were smaller (median body surface area, 1.42 versus 1.93 m2; P=0.002) and younger (median age, 13.0 versus 20.9 years; P=0.02) at AVR. Pathology demonstrated diffuse intrinsic leaflet calcification, not associated with inflammation or infection, and virtually immobile leaflets in closed position. Conclusions— Young patients undergoing AVR with Mitroflow LXA pericardial valves are at high risk for rapid progression from mild or less to severe aortic stenosis over months, highlighting their need for heightened echocardiographic surveillance and suggesting that this aortic bioprosthesis should not be implanted in the young. Current data are insufficient to assess the safety of AVR with other pericardial bioprostheses in children and the youngest adults.

Younger age and valve oversizing are predictors of structural valve deterioration after pulmonary valve replacement in patients with tetralogy of Fallot

OBJECTIVE We sought to identify predictors of structural valve deterioration after pulmonary valve replacement in patients with tetralogy of Fallot. METHODS A retrospective review of 227 patients with tetralogy of Fallot who underwent stented bioprosthetic pulmonary valve replacement at Childrens Hospital Boston between 1994 and 2009 was performed. Patient and valve characteristics were assessed as potential predictors of structural valve deterioration by using univariate and multivariable analysis. Freedom from pulmonary valve reintervention and structural valve deterioration were determined by using Kaplan-Meier analysis. RESULTS Two hundred twenty-nine pulmonary valve replacement operations were performed, with no early mortalities. Freedom from reintervention and structural valve deterioration were 94% (95% confidence interval, 87%-100%) and 74% (95% confidence interval, 63%-85%) at 5 years, respectively, and median time to reintervention was 6.4 years (range, 2-10.1 years). Younger age and higher indexed valve internal diameter were predictors of reduced time to structural valve deterioration. Among patients aged less than 20 years at the time of pulmonary valve replacement, indexed valve internal diameter was a significant predictor of increased risk of structural valve deterioration. Valve manufacturer was not a significant predictor of structural valve deterioration. CONCLUSIONS Younger age at the time of pulmonary valve replacement and valve oversizing in patients less than 20 years of age at the time of pulmonary valve replacement were significant predictors of structural valve deterioration and could potentially affect the timing of pulmonary valve replacement and the extent of valve oversizing in small children. No statistically significant difference in valve performance was seen between bioprosthetic valve types at short-term follow-up.

Interaction of hyperthermia and chemotherapy agents; cell lethality and oncogenic potential

Hyperthermia was combined with bleomycin, melphalan and cis-platinum in order to examine cell lethality and oncogenic transformation in C3H10T1/2 cells from the adjuvant use of heat with chemotherapy agents. When cells were exposed concurrently to 42.5 degrees C and each of the three chemotherapy agents, heat enhanced both the cytotoxic and oncogenic potential of the drugs. Hyperthermia-enhanced ratios were largest for bleomycin-treated cells. Examination of transformation incidences expressed as a function of surviving fraction, i.e. the cytotoxicity of treatment and therefore drug-heat efficacy, showed that for a given level of cell killing the combination of heat and cis-platinum resulted in fewer transformants per surviving cell than for cis-platinum alone. Hyperthermia appears to reduce the oncogenic potential of low concentrations of melphalan but has no effect on bleomycin-induced oncogenic transformation.

Surgical technical performance scores are predictors of late mortality and unplanned reinterventions in infants after cardiac surgery

OBJECTIVE We have previously shown that surgical Technical Performance Scores (TPS) are important predictors of early postoperative morbidity across a wide spectrum of procedures and that intraoperative recognition and intervention of residual defects resulted in improved outcomes. We hypothesized that these scores would also be important predictors of midterm outcomes. METHODS Neonates and infants aged younger 6 months were prospectively followed from the index surgery for a minimum of 1 year. The TPS were calculated using previously published criteria, including intraoperative course, predischarge echocardiograms or catheterizations, and clinical data, and graded as optimal, adequate, or inadequate. Case complexity was determined by the Risk Adjustment for Congenital Heart Surgery-1 category. The primary outcome was mortality, and the secondary outcome was the need for unplanned reinterventions. Outcomes were analyzed using nonparametric methods and a logistic regression model. RESULTS A total of 166 patients were included in our study, with 7 early deaths. The remaining 159 patients (Risk Adjustment for Congenital Heart Surgery-1 category 4-6, 76 [48%]; neonates, 78 [49%]) were followed for a minimum of 1 year after surgery. There were 14 late deaths or late transplantations and 55 late reinterventions. On univariate analysis, the TPS were associated with mortality (P < .001) and reintervention (P = .04). On logistic regression analysis, inadequate TPS was associated with late mortality (P < .001; odds ratio, 7.2; 95% confidence interval, 2.2-23.6), and Risk Adjustment for Congenital Heart Surgery-1 category (P = .004; odds ratio, 3.7; 1.5-8.8) at index surgery was associated with need for late unplanned reintervention. CONCLUSIONS Technical performance affects midterm survival after infant heart surgery. Inadequate TPS can be used to prospectively identify patients at ongoing risk of demise and the need for reintervention. An aggressive approach to diagnosing and treating residual lesions at the initial operation is warranted.

A premounted stent that can be implanted in infants and re-dilated to 20 mm: Introducing the Edwards Valeo Lifestent†

Intravascular stenting (IS) for vascular stenoses in congenital heart disease provides superior gradient relief and angiographic results over balloon angioplasty (BA) alone. The advantages of IS, however, are difficult to apply to infants, toddlers, and small children due to technical challenges in placing large, long sheaths and the risk of creating future stenoses in stents that cannot be re‐dilated to keep pace with somatic growth. This report highlights the Edwards premounted re‐dilatable biliary stent, which was safely placed in four infants and small children with excellent hemodynamic and angiographic results. Bench testing revealed the stent has adequate radial strength and can be re‐dilated to a maximal diameter of 20 mm.

Congenital Mitral Valve Stenosis: Anatomic Variants and Surgical Reconstruction

Congenital mitral valve stenosis is a heterogeneous group of lesions that can occur as an isolated defect or, more commonly, in association with other left heart obstructive defects. Age at presentation, presence and severity of pulmonary hypertension, and location of the primary obstructing lesion have been shown to be important risk factors for survival and long-term outcomes. Anatomic features vary, and obstructing tissue or tethering structures can be present at all levels of the valve, including supra-annular, intra-leaflet, and sub-valvar. Surgical techniques aim to remove abnormal tissue that is causing the obstruction or impediment to adequate leaflet mobility, and improve the mobility of the sub-valve structures. We describe a series of surgical options for mitral valve reconstruction that address the specific pathologies frequently found in congenital mitral stenosis.

Direct tracheobronchopexy to correct airway collapse due to severe tracheobronchomalacia: Short-term outcomes in a series of 20 patients

PURPOSE Tracheobronchomalacia (TBM) is associated with esophageal atresia, tracheoesophageal fistulas, and congenital heart disease. TBM results in chronic cough, poor mucous clearance, and recurrent pneumonias. Apparent life-threatening events or recurrent pneumonias may require surgery. TBM is commonly treated with an aortopexy, which indirectly elevates tracheas anterior wall. However, malformed tracheal cartilage and posterior tracheal membrane intrusion may limit its effectiveness. This study describes patient outcomes undergoing direct tracheobronchopexy for TBM. METHODS The records of patients that underwent direct tracheobronchopexy at our institution from January 2011 to April 2014 were retrospectively reviewed. Primary outcomes included TBM recurrence and resolution of the primary symptoms. Data were analyzed by McNemars test for matched binary pairs and logistic regression modeling to account for the endoscopic presence of luminal narrowing over multiple time points per patient. RESULTS Twenty patients were identified. Preoperative evaluation guided the type of tracheobronchopexy. 30% had isolated anterior and 50% isolated posterior tracheobronchopexies, while 20% had both. Follow-up was 5 months (range, 0.5-38). No patients had postoperative ALTEs, and pneumonias were significantly decreased (p=0.0005). Fewer patients had tracheobronchial collapse at postoperative endoscopic exam in these anatomical regions: middle trachea (p=0.01), lower trachea (p<0.001), and right bronchus (p=0.04). CONCLUSION The use of direct tracheobronchopexy resulted in ALTE resolution and reduction of recurrent pneumonias in our patients. TBM was also reduced in the middle and lower trachea and right mainstem bronchus. Given the heterogeneity of our population, further studies are needed to ascertain longer-term outcomes and a grading scale for TBM severity.

Hypercoagulability markers predict thrombosis in single ventricle neonates undergoing cardiac surgery.

BACKGROUND Incidence of thrombosis in neonates undergoing cardiac surgery is as high as 20%, and single ventricle physiology (SVP) may present an even higher risk. We hypothesize that SVP is a risk factor for thrombosis in neonates undergoing cardiac surgery, and hypercoagulability biomarkers are predictive of postoperative thrombosis. METHODS Records of 512 neonates undergoing cardiac surgery were retrospectively reviewed. Thrombosis was defined by clinical events (shunt thrombosis, limb ischemia, and stroke) or intravascular or cardiac thrombus by echocardiography. Clinical variables, including SVP and cardiopulmonary bypass (CPB), were analyzed using multivariable logistic regression. A hypercoagulability biomarker panel was obtained in a subset of patients with SVP and compared between neonates with and without thrombosis. RESULTS Thrombosis was detected in 51 of 512 neonates undergoing cardiac surgery. Intensive care and hospital lengths of stay were longer in patients who experienced thrombosis compared with those who did not (14 ± 13 vs 6 ± 1 days, 23 ± 4 vs 13 ± 1 days, p < 0.001). The SVP and use of CPB were significant risk factors for thrombosis, and the rate of thrombosis in SVP patients was 16.2% (16 of 99) compared with 8.5% (35 of 413) in non-SVP patients (p = 0.038). Thrombin generation, plasminogen activator inhibitor, and thrombin activatable fibrinolysis inhibitor were significantly elevated in SVP patients with thrombosis compared to without thrombosis (p < 0.05). CONCLUSIONS Single ventricle physiology patients are at higher risk for thrombosis compared with other neonates after cardiac surgery. Hypercoagulable panel testing may help risk stratify patients and guide patient specific anticoagulation management in the postoperative period.

Technical Performance Scores in Congenital Cardiac Operations: A Quality Assessment Initiative

BACKGROUND Technical performance in congenital cardiac operations and its association with clinical outcomes was previously examined in infants and neonates. The purpose of this study was the development and implementation of a system for measuring technical performance in the majority of congenital cardiac operations to be used as a surgeons self-assessment tool. METHODS Using the methodologic framework piloted at our institution, measures of technical performance were created for more than 90% of all congenital cardiac operations. Each operation was divided into multiple subprocedures to be assessed separately. Criteria for technical scores were created using a consensus panel of senior clinicians and were based primarily on the predischarge echocardiographic findings and need for early postoperative reinterventions. This system of procedure modules was then piloted by prospectively assigning technical scores to all patients undergoing operations. RESULTS Thirty modules were created covering more than 90% of the cardiac operations performed. One hundred eighty-five patients were enlisted. One hundred one (54.6%) cases were scored as class 1 (highest), 46 (24.9%) cases as class 2, 22 (11.9%) cases as class 3 (lowest); 16 cases (8.6%) could not be scored. The results were further analyzed by RACHS (Risk Adjustment for Congenital Heart Surgery) categories and outcomes. Valve-procedure-specific criteria were calibrated to reflect specific echocardiographic measurements. CONCLUSIONS The development and implementation of a broad technical performance self-assessment system for congenital cardiac operations is possible. Based on this scoring system, the impact of a less than optimal (2 or 3) technical score depends on case risk category, with higher mortality in the higher risk group, and increased resource use for lower risk procedures.