Technical Performance Score Predicts Perioperative Outcomes in Complex Congenital Heart Surgery Performed in a Small-to-Medium-Volume Program.

As the quality of surgical outcomes depend on many factors, the development of validated tools to assess the different aspects of complex multidisciplinary teams' performance is crucial. The Technical Performance Score (TPS) has only been validated to correlate with outcomes in large-volume surgical programs. Here we assess the utility of TPS in correlation to perioperative outcomes for complex congenital heart surgeries (CHS) performed in a small-to-medium-volume program. 673 patients underwent CHS from 4/2012 to 12/2017 at our institution. Of those, 122 were STAT 4 and STAT 5. TPS was determined for each STAT 4 and STAT 5 operation using discharge echocardiogram: 1 = optimal, 2 = adequate, 3 = inadequate. Patient outcomes were compared including mortality, length of stay, ventilation times, and adverse events. 69 patients (57%) were neonates, 32 (26%) were infants, 17 (14%) were children, 4 (3%) were adults. TPS class 1 was assigned to 85 (70%) operations, TPS class 2 was assigned to 25 (20%) operations, and TPS class 3 was assigned to 12 (10%) operations. TPS was associated with re-intubation, ICU length of stay, postoperative length of stay, and mortality. TPS did not correlate with unplanned 30-day readmissions, need for reoperation, and inotropic score. Technical performance score was associated with perioperative outcomes and is a useful tool to assess the adequacy of repair for high complexity CHS in a small-to-medium-volume surgical program. TPS should be a part of program review in congenital heart programs of all sizes to identify strategies that may reduce postoperative morbidity and potentially improve long-term outcomes.

Multicenter Assessment of Radiation Exposure during Pediatric Cardiac Catheterizations Using a Novel Imaging System.

OBJECTIVES: To quantify radiation exposure during pediatric cardiac catheterizations performed by multiple operators on a new imaging platform, the Artis Q.zen (Siemens Healthcare, Forchheim, Germany), and to compare these data to contemporary benchmark values. BACKGROUND: The Artis Q.zen has been shown to achieve significant radiation reduction during select types of pediatric cardiac catheterizations in small single-center studies. No large multicenter study exists quantifying patient dose exposure for a broad spectrum of procedures. METHODS: Retrospective collection of Air Kerma (AK) and dose area product (DAP) for all pediatric cardiac catheterizations performed on this new imaging platform at four institutions over a two-year time period. RESULTS: A total of 1,127 pediatric cardiac catheterizations were analyzed. Compared to dose data from earlier generation Artis Zee imaging systems, this study demonstrates 70-80% dose reduction (AK and DAP) for similar patient and procedure types. Compared to contemporary benchmark data for common interventional procedures, this study demonstrates an average percent reduction in AK and DAP from the lowest dose saving per intervention of 39% for AK and 27% for DAP for transcatheter pulmonary valve implantation up to 77% reduction in AK and 70% reduction in DAP for atrial septal defect closure. CONCLUSION: Use of next-generation imaging platforms for pediatric cardiac catheterizations can substantially decrease patient radiation exposure. This multicenter study defines new low-dose radiation measures achievable on a novel imaging system.

Early Pulmonary Vascular Disease in Young Adults Born Preterm.

Rationale: Premature birth affects 10% of live births in the United States and is associated with alveolar simplification and altered pulmonary microvascular development. However, little is known about the long-term impact prematurity has on the pulmonary vasculature.Objectives: Determine the long-term effects of prematurity on right ventricular and pulmonary vascular hemodynamics.Methods: Preterm subjects (n = 11) were recruited from the Newborn Lung Project, a prospectively followed cohort at the University of Wisconsin-Madison, born preterm with very low birth weight (≤1,500 g; average gestational age, 28 wk) between 1988 and 1991. Control subjects (n = 10) from the same birth years were recruited from the general population. All subjects had no known adult cardiopulmonary disease. Right heart catheterization was performed to assess right ventricular and pulmonary vascular hemodynamics at rest and during hypoxic and exercise stress.Measurements and Main Results: Preterm subjects had higher mean pulmonary arterial pressures (mPAPs), with 27% (3 of 11) meeting criteria for borderline pulmonary hypertension (mPAP, 19-24 mm Hg) and 18% (2 of 11) meeting criteria for overt pulmonary hypertension (mPAP ≥ 25 mm Hg). Pulmonary vascular resistance and elastance were higher at rest and during exercise, suggesting a stiffer vascular bed. Preterm subjects were significantly less able to augment cardiac index or right ventricular stroke work during exercise. Among neonatal characteristics, total ventilatory support days was the strongest predictor of adult pulmonary pressure.Conclusions: Young adults born preterm demonstrate early pulmonary vascular disease, characterized by elevated pulmonary pressures, a stiffer pulmonary vascular bed, and right ventricular dysfunction, consistent with an increased risk of developing pulmonary hypertension.

Consequences of an early catheter-based intervention on pulmonary artery growth and right ventricular myocardial function in a pig model of pulmonary artery stenosis.

OBJECTIVE: To determine the consequences of an early catheter-based intervention on pulmonary artery (PA) growth and right ventricular (RV) myocardial function in an animal model of branch PA stenosis. BACKGROUND: Acute results and safety profiles of deliberate stent fracture within the pulmonary vasculature have been demonstrated. The long-term impact of early stent intervention and deliberate stent fracture on PA growth and myocardial function is not understood. METHODS: Implantation of small diameter stents was performed in a pig model of left PA stenosis at 6 weeks (10 kg) followed by dilations at 10 (35 kg) and 18 weeks (65 kg) with intent to fracture and implant large diameter stents. Hemodynamics, RV contractility, and 2D/3D angiography were performed with each intervention. The heart and pulmonary vasculature were histologically assessed. RESULTS: Stent fracture occurred in 9/12 and implantation of large diameter stents was successful in 10/12 animals with no PA aneurysms or dissections. The final stented PA segment and distal left PA branch origins equaled the corresponding PA diameters of sham controls. Growth of left PA immediately beyond the stent was limited and there was diffuse fibro-intimal proliferation within the distal left and right PA. RV contractility was diminished in the intervention group and the response to dobutamine occurred uniquely via increases in heart rate. CONCLUSIONS: Early stent intervention in this surgically created PA stenosis model was associated with improved growth of the distal PA vasculature but additional investigation of PA vessel physiology and impact on the developing heart are needed.

Radiation Reduction Capabilities of a Next-Generation Pediatric Imaging Platform.

The aims of this study were to quantify patient radiation exposure for a single interventional procedure during transition from an adult catheterization laboratory to a next-generation imaging system with pediatric settings, and to compare this radiation data to published benchmarks. Radiation exposure occurs with any X-ray-directed pediatric catheterization. Technologies and imaging techniques that limit dose while preserving image quality benefit patient care. Patient radiation dose metrics, air kerma, and dose-area product (DAP) were retrospectively obtained for patients <20 kg who underwent patent ductus arteriosus (PDA) closure on a standard imaging system (Group 1, n = 11) and a next-generation pediatric imaging system (Group 2, n = 10) with air-gap technique. Group 2 radiation dose metrics were then compared to published benchmarks. Patient demographics, procedural technique, PDA dimensions, closure devices, and fluoroscopy time were similar for the two groups. Air kerma and DAP decreased by 65-70% in Group 2 (p values <0.001). The average number of angiograms approached statistical significance (p value = 0.06); therefore, analysis of covariance (ANCOVA) was conducted that confirmed significantly lower dose measures in Group 2. This degree of dose reduction was similar when Group 2 data (Kerma 28 mGy, DAP 199 µGy m(2)) was compared to published benchmarks for PDA closure (Kerma 76 mGy, DAP 500 µGy m(2)). This is the first clinical study documenting the radiation reduction capabilities of a next-generation pediatric imaging platform. The true benefit of this dose reduction will be seen in patients requiring complex and often recurrent catheterizations.

Inspiratory and expiratory resistance cause right-to-left bubble passage through the foramen ovale.

A patent foramen ovale (PFO) is linked to increased risk of decompression illness in divers. One theory is that venous gas emboli crossing the PFO can be minimized by avoiding lifting, straining and Valsalva maneuvers. Alternatively, we hypothesized that mild increases in external inspiratory and expiratory resistance, similar to that provided by a SCUBA regulator, recruit the PFO. Nine healthy adults with a Valsalva-proven PFO completed three randomized trials (inspiratory, expiratory, and combined external loading) with six levels of increasing external resistance (2-20 cmH2 O/L/sec). An agitated saline contrast echocardiogram was performed at each level to determine foramen ovale patency. Contrary to our hypothesis, there was no relationship between the number of subjects recruiting their PFO and the level of external resistance. In fact, at least 50% of participants recruited their PFO during 14 of 18 trials and there was no difference between the combined inspiratory, expiratory, or combined external resistance trials (P > 0.05). We further examined the relationship between PFO recruitment and intrathoracic pressure, estimated from esophageal pressure. Esophageal pressure was not different between participants with and without a recruited PFO. Intrasubject variability was the most important predictor of PFO patency, suggesting that some individuals are more likely to recruit their PFO in the face of even mild external resistance. Right-to-left bubble passage through the PFO occurs in conditions that are physiologically relevant to divers. Transthoracic echocardiography with mild external breathing resistance may be a tool to identify divers that are at risk of PFO-related decompression illness.

Coarctectomy combined with an interdigitating arch reconstruction results in a lower incidence of recurrent arch obstruction after the Norwood procedure than coarctectomy alone.

OBJECTIVE: Recurrent aortic arch obstruction after the Norwood procedure continues to be a source of morbidity. We sought to determine if a modified interdigitating technique for aortic arch reconstruction during the Norwood procedure decreased recurrent arch obstruction. METHODS: A total of 142 consecutive infants undergoing the Norwood procedure were divided into groups according to surgical technique: Group 1 (n = 79, January 1999 to May 2003) underwent arch reconstruction with complete coarctectomy followed by anastomosis of the descending aorta to the transverse arch. Group 2 (n = 63, June 2003 to September 2006) underwent complete coarctectomy plus a modified interdigitating technique. Catheterization before stage 2 palliation was reviewed for hemodynamics and angiographic arch dimensions, and a coarctation index was calculated. RESULTS: Reintervention for recurrent coarctation occurred in 28% (22/79) of group 1 patients compared with 2% (1/63) of group 2 patients (P = .001). Aortic pressures, gradients, dimensions, and coarctation index were consistently more favorable for group 2. CONCLUSIONS: Coarctectomy plus an interdigitating arch anastomosis was superior to coarctectomy alone and resulted in a dramatically decreased incidence of recurrent arch obstruction.

Mixed venous oxygen saturation monitoring after stage 1 palliation for hypoplastic left heart syndrome.

BACKGROUND: Staged palliation for hypoplastic left heart syndrome has been marked by high early mortality due to the limited cardiac output of the postischemic single right ventricle combined with the inefficiency and volatility of parallel circulation. METHODS: Since July 1996, we have performed stage 1 palliation (S1P) in 178 patients. Within this group is a consecutive cohort of 116 patients with true hypoplastic left heart syndrome that underwent S1P with a modified Blalock-Taussig shunt. A prospective database containing postoperative hemodynamic data was maintained on all patients. Studied were the incidence of organ failure, extracorporeal membrane oxygenation (ECMO), and mortality, as well as the relationship between these outcomes and postoperative hemodynamics. RESULTS: Hospital survival for this cohort was 93% (108/116). Patients who died after S1P had a lower superior vena cava oxygen saturation (SVO2) level compared with survivors (53.1% +/-10.6% versus 59.3% +/-9.2%, p = 0.034). Renal failure developed in 2 (1.7%) of the 116 patients, necrotizing enterocolitis developed in 1 (0.9%), and 5 (4.3%) had clinical seizures. ECMO support was instituted in 12 patients (10.3%). The SVO2 level was lower in patients requiring ECMO (54.0% +/- 9.7% versus 59.9% +/- 9.2%, p = 0.031). CONCLUSIONS: Goal-directed therapy with SVO2 as an indicator of systemic oxygen delivery is associated with excellent early survival and a low incidence of organ failure after S1P. Inability to optimize SVO2 in the early postoperative period is associated with an increased risk of organ failure, ECMO, and death.

The effect of common origin of the carotid arteries in neurologic outcome after neonatal ECMO.

BACKGROUND: Common origin of the carotid arteries (COCA) is a normal anatomic variant reported to occur in approximately 11% of the general population. The objective of this study was to determine whether this variant places venoarterial extracorporeal membrane oxygenation (ECMO) patients at a higher risk for adverse neurologic sequelae owing to potential occlusion of both carotid arteries by the arterial cannula. METHODS: The authors reviewed clinical records and echocardiograms of the initial 220 ECMO patients at their institution. Aortic arch morphology was determined by a pediatric cardiologist blinded to all other data. After exclusion of predetermined patients, 131 patients were divided into 2 groups: those with separate origin of the carotid arteries (n = 111) and those with COCA (n = 20). The neurologic outcome variables studied included the results of magnetic resonance imaging (MRI); computed tomography (CT); electroencephalogram (EEG); brainstem auditory-evoked response (BAER), head ultrasound scan, and Bayley Scales of Infant Development reported as Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI). RESULTS: COCA had no predictive value in determining PDI and MDI outcomes and no significance in predicting an increased risk of adverse neurologic sequelae based on MRI, CT, EEG, BAER, or head ultrasound scan. CONCLUSIONS: This study confirms that COCA is a common aortic arch variant (15%, n = 20 of 131) and that this variant does not appear to increase the risk of neurologic injury in infants undergoing venoarterial ECMO.