Faculty Bibliography

BACKGROUND: Bacterial infection (BI) after congenital heart surgery (CHS) is associated with increased morbidity and is difficult to differentiate from systemic inflammatory response syndrome caused by cardiopulmonary bypass (CPB). Procalcitonin (PCT) has emerged as a reliable biomarker of BI in various populations. AIM: To determine the optimal PCT threshold to identify BI among children suspected of having infection following CPB. SETTING AND DESIGN: Single-center retrospective observational study. MATERIALS AND METHODS: Medical records of all the patients admitted between January 2013 and April 2015 were reviewed. Patients in the age range of 0-21 years of age who underwent CHS requiring CPB in whom PCT was drawn between postoperative days 0-8 due to suspicion of infection were included. STATISTICAL ANALYSIS: The Wilcoxon rank-sum test was used for nonparametric variables. The diagnostic performance of PCT was evaluated using a receiver operating characteristic (ROC) curve. RESULTS: Ninety-eight patients were included. The median age was 2 months (25th and 75th interquartile of 0.1-7.5 months). Eleven patients were included in the BI group. The median PCT for the BI group (3.42 ng/mL, 25th and 75th interquartile of 2.34-5.67) was significantly higher than the median PCT for the noninfected group (0.8 ng/mL, 25th and 75th interquartile 0.38-3.39), P = 0.028. The PCT level that yielded the best compromise between the sensitivity (81.8%) and specificity (66.7%) was 2 ng/mL with an area under the ROC curve of 0.742. CONCLUSION: A PCT less than 2 ng/mL makes BI unlikely in children suspected of infection after CHS.

Background: Complex ventricular-arterial (VA) relationships in patients with double outlet right ventricle (DORV) make preoperative assessment of potential repair pathways challenging. The relationship of the ventricular septal defect (VSD) to one or both great arteries must be understood and this influences the choice of surgical procedure [1] In neonates and infants with DORV, Computed Tomography (CT) is often performed due to the ability to get high spatial resolution and ECG gated images [2], however it is possible to get the necessary information from Magnetic Resonance (MR) imaging with an added advantage of avoiding exposure to ionizing radiation. Both CT and MR allow image acquisition in three dimensions (3D) but traditional viewing of the anatomy using the multiplanar reformatting is actually done in two dimensions (2D). Volume rendering from either modality may also be performed, but typically only the external vascular anatomy is depicted. We hypothesized that it is possible to accurately define the intracardiac anatomy in infants with DORV using virtual and physical 3D printed (rapid prototyped) models created from either MR or CT and this can both aid in better defining potential VA pathways and may assist in surgical decision making. Methods: Virtual and physical 3D models were generated for three patients with DORV. Non-ECG-gated 3D spoiled fast gradient echo sequence MR angiography was used for two patients. Retrospective ECG gated CT angiography images acquired in diastole were used in the third patient (to better define the coronary arteries given the suspicion of a single coronary artery by echocardiography). Blood pool segmentation (Figure 1a) was performed in all the three patients (Mimics, Materialise, Leuven, Belgium). A 2 mm shell was added to the blood pool and it was hollowed to create a patient specific heart replica (3-matic, Materialise, Leuven, Belgium). All virtual models were cut to best demonstrate the VA relationships and the models were printed. Results: The VSD and VA relationships were well visualized in all three patients using both the virtual and physical models (Figure 1b,c). The models helped the surgeons better understand the anatomy in all patients: in two patients the surgical plan was altered while the plan was confirmed in the third patient (Table 1). Conclusions: Construction of 3D models in patients with DORV is feasible and allows for extensive examination and surgical planning. This may facilitate a focused and informed surgical procedure and improve the potential for successful outcome. For purposes of DORV, non-gated MRA is sufficient to delineate the VA relationships adequately for 3D printing and enhanced clinical decision-making. CT imaging should be reserved for only those patients where additional information like coronary artery anatomy is desired

Indexed left ventricular end-diastolic volume (ILVEDV) is commonly used in evaluating "borderline left ventricle (LV)" in hypoplastic left heart complex (HLHC) to determine if the LV can sustain adequate systemic cardiac output. Commonly used quantification methods include biplane Simpson or the traditional five-sixth area length "bullet" methods, which have been shown to underestimate true LV volumes, when septal position is mildly abnormal. Subxiphoid five-sixth area length method is proposed as a more accurate estimate of true LV volume in the evaluation of borderline LV.

Persistent fifth arch (PFA) is a rare anomaly that is often underdiagnosed and missed. Different PFA types that have been reported in the literature are systemic-to-systemic type (most common), systemic-to-pulmonary artery (PA), and PA-to-systemic types. The designations of systemic-to-PA or PA-to-systemic are based on if the PFA is a source of PA or systemic blood flow, respectively, in the setting of critical proximal obstruction (pulmonary atresia or aortic atresia). This case describes an unusual PFA, which connects the distal PA to distal ascending aorta; however, it is not associated with critical proximal obstruction, and while it appeared to be an incidental finding in early gestation, progressive serial distal obstruction of the left fourth arch was seen to develop. This case highlights that prenatal diagnosis of PFA is possible and that once a diagnosis is made, serial fetal echocardiograms should be performed to evaluate for evolving lesions.

Background: Complex muscular ventricular septal defects (CMVSD) are often difficult to surgically close and managed by device closure. The pre-intervention imaging is crucial in defining the anatomy and aids in patient selection. We hypothesized that 3D physical and virtual models in patients with CMVSD is feasible, would assist in patient selection and aid in the successful device closure. Methods: Virtual and physical 3D models on 3 patients with CMVSD were generated from CT or MRI data, using Mimics, and 3-Matic software. The first patient had history of complicated and unsuccessful prior device closures, with residual shunt. Two physical models, with and without devices in situ were printed (Figure 1A) for this patient. Two virtual models were generated in the other two patients. Results: The location, size, trabeculations, papillary and muscle bundles were clearly visualized in all patients. The two physical models were extensively studied, resulting in successful device closure of the residual VSD. The virtual model on patient 2 identified RV papillary muscles adjacent to the CMVSD (Figure 1B) precluding device closure. The patient 3 model identified muscle bundles crowding the VSD suggesting potential for spontaneous closure. Conclusion: Construction of 3D models in patients with CMVSD is feasible, assists in appropriate patient selection and allows for extensive examination and planning. This may facilitate a focused and informed procedure and improve the potential for successful closure. (Figure Presented)

Learning Objectives: Pulmonary hypertension (PH) is a serious complication that occurs in some patients following congenital heart surgery (CHS) and increases mortality risk. Inhaled (INH) iloprost is a prostacyclin analog that has been successfully used in pediatric patients but data are limited. We hypothesize that INH iloprost is safe and effective for prevention or treatment of post-operative PH and can be weaned by protocol in pediatric patients following CHS. Methods: This was a retrospective review of pediatric patients who underwent CHS at our institution from January 2013 to May 2014. All patients who received INH iloprost for prevention or treatment of PH were included. There were no exclusion criteria. The primary outcome measures were the efficacy and safety of INH iloprost defined by the effect on the pulmonary to systemic pressure ratio (P/S) and systolic blood pressure (SBP) respectively. Secondary outcomes included evaluation of INH iloprost dosing and weaning strategy. The Wilcoxon signed rank test was used to compare measures. P values less than 0.05 were considered significant. Results: Sixteen patients were included with a median age at surgery of 2 months (0.07 to 136 months) and a median weight of 3.9 kg (2.2 to 25.4 kg). The median starting dose of INH iloprost was 0.5 mcg/ kg (0.2- 1.25 mcg/kg). Two patients had the dose increased during the treatment period. Fifteen patients received the drug every two hours at initiation. Following initiation of INH iloprost median P/S decreased in all patients (0.69 to 0.39; p<0.005) and there was no change in median SBP (71.5 versus 72.9 mmHg; p=0.08). Eight patients were weaned to an every four hour and then every eight hour regimen prior to discontinuation. Median overall wean duration was 48 hours. No patients suffered a pulmonary hypertensive crisis during or after the treatment period. Conclusions: INH iloprost is safe and effective for prevention or treatment of post-operative PH following pediatric CHS. A dose of 0.5 mcg/kg administered every 2 hours is effective, well tolerated and may be safely weaned off over 48 hours

In this case report, we describe the use of the Aquadexâ„¢ system for ultrafiltration therapy in the pediatric cardiac intensive care setting in a patient with fluid overload and acute kidney injury after congenital heart surgery. The patient is an 11-year-old, 25 kg male with complex single ventricle anatomy who underwent a one and a half ventricle repair. The patient experienced multiple organ dysfunction syndrome including acute kidney injury in the early post-operative period secondary to low cardiac output syndrome and tachyarrhythmia. Ultrafiltration using the Aquadexâ„¢ system was utilized to treat fluid overload in the setting of acute kidney injury and hemodynamic instability. Negative fluid balance was safely achieved. It was subsequently possible to wean ventilatory and inotropic support. We conclude that the use of ultrafiltration therapy is feasible in hemodynamically unstable pediatric patients with significant fluid overload in the setting of acute kidney injury following congenital heart surgery.

A vascular ring (VR) is a rare congenital anomaly that has variable clinical presentation, but may cause trachea-esophageal compressive symptoms. We describe an infant with cystic fibrosis and subtle trachea-esophageal compressive symptoms which were initially attributed to other causes, delaying the diagnosis of a VR