Faculty Bibliography

BACKGROUND:Thrombosis and occlusion of the superior vena cava (SVC) can cause massive chylothorax resulting in significant morbidity and mortality among young infants. Medical therapy is often unsuccessful. We report a new surgical technique that entails open thrombectomy and reconstruction of the SVC and innominate vein to treat this condition. METHODS:The charts of 4 consecutive infants with chylothoraces refractory to conservative management were reviewed. The operations were performed on cardiopulmonary bypass without myocardial arrest. The SVC and innominate veins were incised open, and thrombectomy was performed. This was followed by homograft patch reconstruction of both the veins. RESULTS:The infants were aged between 5 weeks to 4 months and had an average weight of 4 kg. All of them had hypoalbuminemia and evidence of hypercoagulable state. After surgical intervention, 3 had complete relief of SVC obstruction. Two of the 3 patients had complete resolution of chylous effusion, and the third patient had a significant decrease in chest tube drainage (70%) by the end of 1 week. The fourth patient had recurrence of high drainage after an initial improvement, and a subsequent angiogram demonstrated stenosis of the SVC without thrombosis. The chest tube drainage finally resolved after balloon angioplasty. CONCLUSIONS:Thrombotic occlusion of the SVC can result in chylothorax that is often not amenable to medical therapy. This is associated with significant loss of proteins and hypercoagulable state. A complete surgical relief of SVC obstruction by open thrombectomy and venoplasty can result in dramatic decrease in chylous output.

OBJECTIVE:Symptomatic neonates with Ebstein's anomaly pose significant challenge. Within this cohort, neonates with associated anatomical pulmonary atresia have higher mortality. We review our experience with this difficult subset. METHODS:A total of 32 consecutive symptomatic neonates with Ebstein's anomaly underwent surgical intervention between 1994 and 2013. Of them, 20 neonates (62%, 20/32) had associated pulmonary atresia. Patients' weights ranged from 1.9 to 3.4 kg. All patients without pulmonary atresia had two-ventricle repair. Of the 20 neonates, 16 (80%, 16/20) with Ebstein's anomaly and pulmonary atresia had two-ventricle repair and 4 had single-ventricle palliation, of which 2 underwent Starnes' palliation and 2 Blalock-Taussig shunts. Six recent patients with Ebstein's anomaly and pulmonary atresia had right ventricle to pulmonary artery valved conduit as part of their two-ventricle repair. RESULTS:Overall early mortality was 28% (9/32). For those without pulmonary atresia, mortality was 8.3% (1/12). For the entire cohort of neonates with Ebstein's anomaly and pulmonary atresia, mortality was 40% (8/20; p=0.05). Mortality for neonates with Ebstein's anomaly and pulmonary atresia having two-ventricle repair was 44% (7/16). Mortality for neonates with Ebstein's anomaly and pulmonary atresia having two-ventricle repair utilising right ventricle to pulmonary artery conduit was 16% (1/6). For those having one-ventricle repair, the mortality was 25% (1/4). CONCLUSIONS:Surgical management of neonates with Ebstein's anomaly remains challenging. For neonates with Ebstein's anomaly and anatomical pulmonary atresia, single-ventricle palliation is associated with lower early mortality compared with two-ventricle repair. This outcome advantage is negated by inclusion of right ventricle to pulmonary artery conduit as part of the two-ventricle repair.

The CentriMag ventricular assist device is an extracorporeal, third-generation, continuous flow device. The rapidity and simplicity of operation along with low priming volume make it attractive for use in children with refractory heart failure. We report the successful use of CentriMag as a bridge to recovery in a child and discuss issues that are unique to its use in children.

Diffuse alveolar hemorrhage (DAH) from systemic lupus erythematosus (SLE) is a rare but potentially life-threatening condition. We report the case of a 14-year-old female with SLE who developed hypoxia and shock secondary to severe alveolar hemorrhage. She was successfully managed by placement on extracorporeal membrane oxygenation (ECMO) followed by emergent pulmonary lobectomy and medical treatment including high-dose methylprednisolone, cyclophosphamide, intravenous immunoglobulin, and plasmapheresis.

OBJECTIVE:The optimal timing for neonatal cardiac surgery is unknown. We aimed to determine the relationship between age at surgery and perioperative outcomes, hypothesizing that earlier intervention would be associated with lower morbidity and mortality. METHODS:A retrospective review was performed of neonates who had undergone an arterial switch operation, stage 1 palliation for functional single ventricle, or systemic-to-pulmonary shunt for obstructed pulmonary blood flow from January 1, 2005, to December 31, 2010. The subjects with clinical indications for delayed surgery or prematurity were excluded. Age at surgery was evaluated as both a continuous and a categorical variable. The primary outcome was a composite endpoint of mortality or prolonged intensive care stay. RESULTS:Of 344 subjects, 286 (77 arterial switch operation, 124 stage 1 palliation, 85 systemic-to-pulmonary shunt) met the inclusion criteria. In each group, age at surgery was not associated with the primary composite endpoint. The patients who died after systemic-to-pulmonary shunt had a median age at surgery of 3 days versus 6 days for the survivors (P = .04). A similar, but nonsignificant, pattern was seen for patients undergoing arterial switch operations (4.5 vs 7 days; P = .09). Earlier surgery was not associated with a reduced duration of vasoactive support, mechanical ventilation, or intensive care unit length of stay in any group. Stage 1 palliation subjects in the upper age quartile (≥8 days) at surgery were less likely to require prolonged mechanical ventilation (P = .03). CONCLUSIONS:Younger age at intervention in the neonatal period was not associated with reduced morbidity or mortality in any procedural subgroup studied. In our cohort, earlier systemic-to-pulmonary shunt for obstructed pulmonary blood flow was associated with a greater likelihood of a poor outcome.

OBJECTIVE:Junctional ectopic tachycardia complicates the postoperative recovery from open heart surgery in children. The reported risk factors include younger age, prolonged cardiopulmonary bypass times, and administration of inotropic agents. Junctional ectopic tachycardia occurs early after open heart surgery, in the setting of relative postoperative sinus node dysfunction, and exhibits QRS morphology consistent with an origin from the atrioventricular node or proximal conduction system. Our goal was to develop a reproducible animal model for postoperative junctional ectopic tachycardia. METHODS:Eleven pigs, aged 2 to 4 months, underwent open heart surgery after induction of general anesthesia. Electrodes were sewn to the left atrium and right ventricle. RESULTS:Sinus node dysfunction was created using clamp crushing without or with radiofrequency ablation (successful in 1 of 5 pigs) or sinus node removal (successful in 4 of 4). After prolonged cardiopulmonary bypass (>120 minutes) alone and with isoproterenol infusion, no spontaneous junctional ectopic tachycardia developed. Junctional ectopic tachycardia or fascicular tachycardia could be initiated after either slow atrioventricular nodal pathway ablation and/or digoxin administration. Junctional ectopic tachycardia occurred in 8 of 9 pigs (mean ventricular rate, 171 ± 32 bpm), and fascicular tachycardia occurred in 9 of 9 pigs (mean ventricular rate, 187 ± 39 bpm). His and right bundle recordings confirmed the conduction system origin. CONCLUSIONS:Experimental junctional ectopic tachycardia or fascicular tachycardia can occur in the intraoperative setting of sinus node dysfunction, prolonged cardiopulmonary bypass, and enhanced conduction system automaticity. Conduction system automaticity occurred after either physical injury (ablation or tricuspid valve stretch) or measures to augment the transient inward current of the conduction system (isoproterenol and digoxin). This animal model can serve as the basis to assess new treatments of postoperative junctional ectopic tachycardia.