Long-Term Follow-Up of Right Ventricle to Pulmonary Artery Biologic Valved Conduits Used in Pediatric Congenital Heart Surgery.

Valved conduit reconstruction between the right ventricle (RV) and the pulmonary circulation is often necessary in the surgical treatment of complex congenital heart defects. The aim of this study is to evaluate the long-term performance of the three types of conduits we have used and assess risk factors for conduit failure. Retrospective, single-center review of 455 consecutive pediatric patients with 625 conduits from 1990 to 2019 undergoing RV-to-pulmonary artery (PA) reconstruction with a valved conduit. The three conduit types investigated were pulmonary homograft, aorta homograft, and bovine jugular vein (BJV) graft. Overall patient survival was 91.4%, freedom from conduit replacement (FCR) was 47.4%, and freedom from reintervention (FFR) was 37.8% with a median follow-up of 8.7 years (interquartile range 4.3-13.3 years). For pulmonary homografts, 10-, 20-, and 28-year FCR was 79.6%, 68.6%, and 66.0%, respectively. For aortic homografts, 10-, 20-, and 30-year FCR was 49.8%, 31.5%, and 23.0%, respectively. For BJV grafts, 10- and 19-year FCR was 68.1% and 46.0%, respectively. When controlling for baseline variables, FCR was similar for pulmonary homografts and BJV grafts. Overall patient survival was excellent. Risk factors for conduit failure in patients operated with reconstruction of the RV-PA outflow tract included low age, low weight, small conduit size, and certain cardiac diagnoses. There was no evidence for a shorter life span of the second graft. Pulmonary homografts and BJV grafts performed similarly but the risk of endocarditis was greater in the BJV group.

Long-term results of aortic arch reconstruction with branch pulmonary artery homograft patches.

BACKGROUND: Homograft tissue is an important reconstructive material used in the surgical correction of a variety of congenital heart defects. The aim of this study is to evaluate the long-term outcome of pulmonary artery (PA) branch patches used in the reconstruction of the thoracic aorta in children. METHODS: Retrospective review of 124 consecutive pediatric patients undergoing corrective surgery for their congenital heart defects between 2001 and 2016. Survival, reoperation, and reintervention data were collected, as well as imaging data to assess for presence of recoarctation, dilation, or aneurysm formation in the area of patch reconstruction. RESULTS: Overall 15-year survival was 83.9% and 15-year freedom from reintervention in the area of patch reconstruction was 89.2%. Rates of mortality (0%), cardiac transplantation (0%), and reoperation (0.8%) attributable to the area of patch reconstruction were low. The frequency of catheter-based intervention in the area of patch reconstruction was 9.7%; such interventions were successful in all but one patient, who ultimately underwent successful surgical aortoplasty. CONCLUSIONS: Homograft patches harvested from PA branches are an effective reconstructive material used for reconstruction of the aorta in small children. Long-term results show no risk of aneurysm formation and low rates of stenosis formation.

Intra-procedural Bronchoscopy to Prevent Bronchial Compression During Pulmonary Artery Stent Angioplasty.

Stenosis of the pulmonary arteries frequently occurs during staged palliation of hypoplastic left heart syndrome and variants, often necessitating stent angioplasty. A complication of stent angioplasty is compression of the ipsilateral mainstem bronchus. Following such a case, we re-evaluated our approach to PA stent angioplasty in these patients. The incident case is described. A retrospective observational study of children and adults with superior (SCPC) and/or total cavopulmonary connection (TCPC) undergoing left pulmonary artery (LPA) stent angioplasty between January 1, 2005 and January 5, 2014 and subsequent chest CT was performed to assess the incidence of bronchial compression. The current strategy of employing bronchoscopy to assess bronchial compression during angioplasty is described with short-term results. Sixty-five children and adults underwent LPA stent angioplasty. Other than the incident case, none had symptomatic bronchial compression. Of the total study population, 12 % had subsequent CT, of which one subject had moderate bronchial compression. To date, seven subjects have undergone angioplasty of LPA stenosis and bronchoscopy. In one case, stent angioplasty was not performed because of baseline bronchial compression, exacerbated during angioplasty. In the rest of cases, mild-moderate compression was seen during angioplasty. Following stent angioplasty, the resultant compression was not worse than that seen on test angioplasty. Bronchial compression is a rare complication of stent angioplasty of the pulmonary arteries in children and adults with SCPC/TCPC. Angioplasty of the region of interest with procedural bronchoscopy can help to identify patients at risk of this complication.

Systemic rapamycin to prevent in-stent stenosis in peripheral pulmonary arterial disease: early clinical experience.

OBJECTIVES: We have taken a novel approach using oral rapamycin - sirolimus - as a medical adjunct to percutaneous therapy in patients with in-stent stenosis and high risk of right ventricular failure. BACKGROUND: Peripheral pulmonary artery stenosis can result in right ventricular hypertension, dysfunction, and death. Percutaneous pulmonary artery angioplasty and stent placement acutely relieve obstructions, but patients frequently require re-interventions due to re-stenosis. In patients with tetralogy of Fallot or arteriopathy, the problem of in-stent stenosis contributes to the rapidly recurrent disease. METHODS: Rapamycin was administered to 10 patients (1.5-18 years) with peripheral pulmonary stenosis and in-stent stenosis and either right ventricular hypertension, pulmonary blood flow maldistribution, or segmental pulmonary hypertension. Treatment was initiated around the time of catheterisation and continued for 1-3 months. Potential side-effects were monitored by clinical review and blood tests. RESULTS: Target serum rapamycin level (6-10 ng/ml) was accomplished in all patients; eight of the nine patients who returned for clinically indicated catheterisations demonstrated reduction in in-stent stenosis, and eight of the 10 patients experienced no significant side-effects. Among all, one patient developed diarrhoea requiring drug discontinuation, and one patient experienced gastrointestinal bleeding while on therapy that was likely due to an indwelling feeding tube and this patient tolerated rapamycin well following tube removal. CONCLUSIONS: Our initial clinical experience supports that patients with peripheral pulmonary artery stenosis can be safely treated with rapamycin. Systemic rapamycin may provide a novel medical approach to reduce in-stent stenosis.

Percutaneous left main coronary artery stent for acute myocardial ischemia after repaired ALCAPA.

Percutaneous coronary artery stent angioplasty is rare in the pediatric population but can be a life-saving by rapidly reestablishing flow to an obstructed coronary artery. It is a technically challenging and high-risk procedure in infants and further limited by the need for future surgical intervention. We report of an infant with anomalous left coronary artery from the pulmonary artery who underwent acutely successful surgical reimplantation of the left coronary artery onto the ascending aorta. One month later, she developed acute myocardial ischemia and emergent catheterization diagnosed near-total occlusion of the left coronary artery. We implanted a 2.5 mm coronary stent in the left main coronary artery with reestablishment of flow. The patient's left ventricular systolic function recovered within 4 weeks and repeat angiography 3 months later showed complete normalization of the entire left coronary artery system. The patient weighed 3 kg and was < 6 weeks of age at the time of stent implantation which to our knowledge is the smallest and youngest reported patient to undergo coronary stent angioplasty. This case supports the feasibility of this procedure in infants as a temporizing solution to hemodynamic instability from myocardial ischemia due to coronary artery stenosis. The left ventricular systolic function remained normal at 7 months after stent placement and the patient was clinically well from a cardiac perspective.

Transcatheter Fontan takedown.

Early failure of the Fontan circulation is rare in the current era but remains associated with a high mortality rate. Surgical Fontan takedown has evolved as one of the strategies to stabilize the circulation, improve survival, and allow for a future attempt at Fontan completion. We have completed Transcatheter fontan takedown in three patients with extracardiac conduits 0.8-6 months following their Fontan operations. Superior vena cava flow was redirected into only the pulmonary arteries by occluding the conduit with a vascular plug between the pulmonary arteries and fenestration and unrestrictive inferior vena cava flow was redirected into only the atrium by stenting and enlarging the fenestration. There were no procedure related complications. All patients had resolution of large-volume chylous pleural effusions. One patient had resolution of protein-losing enteropathy, two patients had improvement of plastic bronchitis. Two of three patients remain alive at latest follow-up (4-24 months). This early experience suggests that Transcatheter fontan takedown is technically feasible and may be an alternative to surgical takedown in select patients with early failure of the Fontan circulation.

A case of neonatal myocardial infarction: left coronary artery thrombus resolution and normalisation of ventricular function by intracoronary low-dose tissue plasminogen activator.

Neonatal myocardial infarction is a rare clinical entity that is associated with high mortality. Reported treatment strategies include supportive care, extracorporeal membrane oxygenation, thrombolytics, and surgical thrombectomy. Herein we report a neonate who developed an acute myocardial infarction owing to a thrombus in the proximal left coronary artery. At 24 hours of life, he was treated with local (intracoronary) thrombolytic therapy at a lower dose than previously reported, as well as with systemic anticoagulation. There was subsequent angiographic resolution of the thrombus and normalisation of left ventricular function.

Evaluation and comparison of patch materials used for pulmonary arterioplasty in pediatric congenital heart surgery.

Objective: To evaluate the long-term performance of the patch materials we have used to augment the pulmonary arterial tree across a wide spectrum of diagnoses and anatomical locations. Methods: Retrospective, single-center review of 217 consecutive pediatric patients at a tertiary referral center from 1993 to 2020 who underwent patch arterioplasty of the pulmonary arterial tree from the pulmonary bifurcation to the distal pulmonary arterial branches. Reintervention data were collected and analyzed. Lesion-specific anatomy and other variables were analyzed as risk factors for reintervention. Results: There were 280 total operations performed (217 initial operations and 63 reoperations) and 313 patches used. The patches used were autologous pericardium (166, 53.0%), pulmonary homograft (126, 40.3%), and a heterogeneous group of other materials (21, 6.7%). Overall patient survival was 86.2%, freedom from reoperation was 81.0% and freedom from reintervention (FFR) was 70.6%, with a median follow-up of 13.8 years (interquartile range, 6.3-17.9 years). For all patches, 10-, 20-, and 27-year FFR was 76.6%, 70.6%, and 70.6%, respectively. FFR was similar among all 3 patch type groups (P = .29). Multivariable Cox regression analysis showed that diagnoses of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries and hypoplastic left heart syndrome, patches placed at initial cardiac operation, and increasing number of cardiac operations were risk factors for reintervention. Conclusions: Autologous pericardium and pulmonary homograft patches performed similarly. Although patch type conferred no difference in need for reintervention, other risk factors did exist. Namely, diagnoses of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries and hypoplastic left heart syndrome, patch placement at a patient's first cardiac operation, and increasing number of cardiac operations were risk factors for reintervention.

Guillain-Barré syndrome in a child with pain: lessons learned from a late diagnosis.

UNLABELLED: Children with Guillain-Barré Syndrome (GBS) often do not present like adults with an ascending paralysis and sensory abnormalities, but typically have pain and gait difficulties as predominant symptoms. We present a case of paediatric GBS that was not diagnosed until late in the course because of limited neurological examination, erroneous interpretation of newly acquired data and insufficient familiarity with the disorder in children. Through this case, essentials of paediatric GBS are reviewed. CONCLUSION: Pain and gait difficulties can be the main features of paediatric GBS at presentation. In addition, a comprehensive neurological exam in any case of weakness or diffuse pain combined with ongoing critical interpretation of a disease course allows for adjustment of a preliminary diagnosis towards a potentially life-threatening disease.

Neurogenesis and brain injury: managing a renewable resource for repair.

The brain shows limited ability to repair itself, but neurogenesis in certain areas of the adult brain suggests that neural stem cells may be used for structural brain repair. It will be necessary to understand how neurogenesis in the adult brain is regulated to develop strategies that harness neural stem cells for therapeutic use.

Reversal of ethanol toxicity in embryonic neurons with growth factors and estrogen.

Prenatal exposure to ethanol is the cause of fetal alcohol syndrome, which is characterized by brain abnormalities and decreased mental capacity. In the current study, cultured neurons from embryonic rat cortices were used to study the reversal of ethanol toxicity on neuronal survival and neurite outgrowth. Ethanol treatment followed by treatment with estrogen and certain growth factors were used to assess the potential of these growth factors and estrogen to reverse the effects of ethanol damage. Cortical neurons from embryonic day (E) 16 rats were grown in defined medium with a glial plane at a distance of 1mm from the neurons. Ethanol (45 mM) was administered on day in vitro 1 (DIV 1) and DIV 4. Insulin-like growth factor-I (IGF-I, 10 ng/ml), insulin-like growth factor-II (IGF-II, 10 ng/ml), basic fibroblast growth factor (bFGF, 5 ng/ml), nerve growth factor (NGF, 100 ng/ml), and estrogen (Es, 10 ng/ml) were administered on DIV 4 and DIV 5. Cell viability was determined on DIV 6 using the intravital dyes fluorescein diacetate and propidium iodide. IGF-I and bFGF reduced ethanol's toxic effect on neuronal survival. Estrogen, bFGF, and NGF increased total neurite length after ethanol treatment. Although none of the treatments had a statistically significant effect on the mean number of primary neurites, all caused a statistically significant increase in the mean number of secondary neurites per cell (a measure of neuritic branching) relative to the ethanol treatment alone.

Right ventricular remodeling after pulmonary valve replacement: early gains, late losses.

BACKGROUND: Although early results of pulmonary valve replacement (PVR) after tetralogy of Fallot repair have been described, information about late postoperative ventricular size and function is lacking. This study was designed to characterize right ventricular (RV) remodeling up to 10 years after PVR. METHODS: Retrospective analysis was conducted of cardiovascular magnetic resonance (CMR) data from 2002 to 2011 in 101 patients (244 studies) who underwent PVR and had one or more post-PVR CMR studies at five post-PVR time intervals up to 10 years. RESULTS: Compared with pre-PVR values, in the 0- to 1-year post-PVR group, pulmonary regurgitation (PR) fraction decreased from 49 ± 11% to 3 ± 2% (p < 0.001), RV end-diastolic volume index (EDVi) decreased by 39% (p < 0.001), RV end-systolic volume index (ESVi) decreased by 33% (p < 0.001), and RV ejection fraction (EF) decreased from 48 ± 8% to 44 ± 8% (p = 0.01). These values remained unchanged through the sixth post-PVR year. However, by 7 to 10 years after PVR (n = 15), RVEDVi and RVESVi were significantly increased and had returned to 84% and 104% of pre-PVR volumes, respectively, and RV EF had declined further. Increasing RV EDVi correlated with increasing grades of PR (rs = 0.36, p < 0.001), tricuspid regurgitation (rs = 0.33, p < 0.001), and RV pressure (rs = 0.32, p = 0.03). CONCLUSIONS: In this cohort, early reduction in RV size showed a gradual return toward preoperative values by 7 to 10 years after PVR. The late adverse RV remodeling was associated with increased RV volume and pressure loads. These findings highlight the palliative nature of PVR and the importance of continued surveillance.

Frequency and risk of in-stent stenosis following pulmonary artery stenting.

Peripheral and central pulmonary artery (PA) stenoses can result in right ventricular hypertension, dysfunction, and death. Percutaneous PA angioplasty and stent placement relieve obstruction acutely, but patients frequently require reintervention. Within a heterogeneous patient population with PA stents referred for catheterization because of noninvasive signs of PA obstruction, we have observed that in-stent stenosis (ISS) occurs commonly in some groups, challenging previous reports that this phenomenon occurs infrequently. We set out to evaluate the incidence and demographics of patients with previous PA stent placement who develop ISS. Consecutive patients with previously placed stents presenting for catheterization and undergoing PA angiography were reviewed (104 patients, 124 cases). We defined ISS angiographically, as a 25% narrowing of the contrast-filled lumen relative to the fluoroscopically apparent stent diameter at any site along the length of the stent. For inclusion, we required that the stenotic segment be narrower or equal in size to the distal vessel. ISS was diagnosed in 24% of patients, with the highest incidence among patients with tetralogy of Fallot and multiple aortopulmonary collaterals, Williams syndrome, or Alagille syndrome. In conclusion, ISS after PA stent placement is a more frequent problem than previously reported, and patients with inherently abnormal PAs are disproportionately affected. Increased clinical surveillance after stent placement and investigation of innovative preventive strategies may be indicated.

Aortopulmonary fistula after outflow tract stent in repaired truncus.

We present a case of an iatrogenic aortopulmonary (AP) fistula in a 9-year-old patient with a history of repaired truncus arteriosus without the use of a right ventricle to pulmonary artery conduit and subsequent transcatheter placement of a right ventricular outflow tract (RVOT) stent. Redilation of the stent resulted in a defect in the aortic wall and the creation of an AP fistula with an associated hemodynamically significant left to right shunt. This case demonstrates a previously unreported adverse event of transcatheter RVOT reintervention after truncus arteriosus repair.