Pulmonary Artery Growth Research Articles

Genotypes identified by genome-wide association analyses influence yearling pulmonary arterial pressure and growth traits in Angus heifers from a high-altitude beef production system

Reducing the prevalence of hypoxia-induced pulmonary hypertension (PH) remains a challenge to high-altitude beef production systems. Previous research and selection strategies have focused on the impact of bulls with PH in gain-test; however, little information is available on heifers that are typically developed in grazing systems. We hypothesized that indicator traits for PH in heifers are genomically associated with growth traits. The objectives of this study were to 1) identify SNP associated with yearling mean pulmonary arterial pressure (YPAP) and growth traits, 2) evaluate sequence variants common to YPAP and growth traits, and 3) identify underlying genes for QTL in Angus cattle. Yearling heifers (n = 1180) grazing in a high-altitude beef production system were measured for YPAP. Additionally, growth measures such as age of dam adjusted birth weight (BW), 205 d weaning weight (WW), 365 d yearling weight (YW), 365 d hip height (HH), and 160 d post-weaning gain (PWG) were also recorded. Isolated DNA from blood, hair, or blood card samples were analyzed using the Ilumina BovineSNP50 Beadchip. Genome-wide association analyses were conducted using an additive multi-locus mixed model with a 5% false discovery rate to account for multiple comparisons. Genotypes adjusted for FDR (P ≤ 1.00E−05; number of SNP) were associated with BW (2), YW (1), PWG (1), and HH (6), but no SNP were associated with YPAP or WW at this significance level. Associated SNP (P ≤ 1.00E−03; number of SNP) were identified for YPAP (37), BW (42), WW (31), YW (38), PWG (36), and HH (65). There was one SNP concordant with YPAP, YW, and HH, another with YPAP, YW, and PWG, and one SNP was concordant between YPAP and BW. Underlying genes within 1 kb of concordant SNP were SLC36A2 and CFAP58 and are involved in small amino acid transportation and cell cycle processes, respectively. Results suggested that 2 genomic regions may co-associate YPAP and growth traits. However, given these SNP accounted for <0.05 percentage of the genomic variance, selection for growth will have limited influence on YPAP and subsequently incidence of hypoxia-induced PH in beef heifers developed in grazing systems.

Blalock-Taussig shunt versus patent ductus arteriosus stent as first palliation for ductal-dependent pulmonary circulation lesions: A review of the literature.

Infants with ductal-dependent pulmonary blood flow (PBF) often undergo a palliative procedure to provide a stable source of PBF prior to definitive palliation or repair. In the current era, a surgical shunt or ductal stent is used to provide PBF. We aimed to review the current literature comparing ductal stents to surgical shunts. Four small, single-center studies and two larger multicenter studies were identified comparing ductal stent to surgical shunt. Combined, these studies showed ductal stent resulted in similar or improved pulmonary artery growth, fewer complications, shorter length of stay, less diuretic use, and improved survival compared to surgical shunt. Despite inherent minor variability among the studies, ductal stent appears to be associated with more frequent reinterventions. Surgical shunts remain essential to the care of these patients, but ductal stent is a reasonable alternative, and may provide some advantages in select patients with ductal-dependent PBF.

Mid-Term Outcome of Right Ventricle to Pulmonary Artery Shunt for Older Children and Young Adults With Ventricular Septal Defect, Pulmonary Atresia, and Hypoplastic Pulmonary Arteries

Management strategy for patients of ventricular septal defect and pulmonary atresia (VSD/PA) with hypoplastic pulmonary arteries presenting in late childhood or adolescence is still controversial. We present our experience with the use of right ventricle-pulmonary artery shunt (RV-PA) in management of this entity. Between January 2014 and April 2018, 25 patients of VSD/PA underwent valveless RV-PA shunt at our center. The size of the RV to PA shunt was calculated as half the expected diameter of the main pulmonary artery. We retrospectively reviewed the data from hospital records. Follow-up data were recorded from outpatient records or via telephone. Mean age of the cohort was 12.25 ± 3.18 years. There was 1 early and 1 interstage mortality. None of the patient developed acute renal failure, ventricular dysfunction, and arrhythmias. At interstage follow-up of 8.28 ± 3.7 months, both Nakata index (from 66.23 ± 24.12 to 185.8 ± 58 mm2/m2) and McGoon ratio (0.9 ± 0.22 vs 49 1.84 ± 0.4) increased significantly compared to preoperative value, whereas RPA-LPA ratio was not significantly changed (1.095 ± 0.39 vs 1.01 ± 0.56, P = 0.63). Prerepair pulmonary vascular resistance in 17 patients, who underwent complete repair, was 2.9 ± 0.69 woods unit/m2. Postrepair right ventricle-left ventricle pressure ratio was 0.5 ± 0.14. There was no early or late mortality and none of the patient required conduit revision or VSD fenestration. On follow-up of 25.75 ± 17.94 months, 16 patients were in NYHA I and 1 patient was in NYHA II. Appropriate-sized RV-PA shunt is an effective strategy for achieving balanced pulmonary artery growth in VSD/PA with hypoplastic pulmonary arteries presenting late without the risk of pulmonary over circulation or systemic malperfusion.

Abstract 17326: The Effect of Maintenance of Antegrade Pulmonary Blood Flow Upon Bidirectional Glenn on Pre- and Post-Fontan Outcomes

Introduction: Maintaining pulsatility at the time of bidirectional Glenn (BDG) has theoretical advantages and disadvantages. The practice is diverse throughout the centers and individual surgeons without clear rationale behind its application. We sought to investigate the impact of antegrade pulmonary blood flow on pre- and post-Fontan outcomes. Methods: From 2003 through June 2014, among 237 patients who underwent BDG as an interim palliation for functional single ventricle (FSV), patients with preexisting pulmonary blood flow from the ventricle before BDG were included and patients undergoing Kawashima operation or having history of Norwood operation or bilateral pulmonary arterial band were excluded (n=151). Patients were grouped by their presence or absence of antegrade pulmonary blood flow following BDG: group 1 (pulsatile) (n=73) or group 2 (non-pulsatile) (n=78). The pre- and post-Fontan outcomes were compared between two groups. Results: Age and weight at BDG were 7 months and 7.8kg. Oxygen saturation was higher in group 1 (84±4%) compared to group 2 (82±4%) before Fontan (p&lt;0.001). The level of brain natriuretic peptide (BNP) was similar before Fontan (p=0.966). In pre-Fontan cardiac catheterization, mean pulmonary arterial pressure was similar (Group 1: 11±4mmHg vs. Group 2: 10±4mmHg, p=0.146), McGoon ratio seemed higher in group 1(2.6±0.6) compared to group 2(2.3±0.4) (p=0.057), and pulmonary vascular resistance was lower in group 1(1.3±0.7) compared to group 2(1.6±0.7)(p=0.038). A total of 136 patients (90%) underwent Fontan operation. Duration of stay in the intensive care unit (p=0.766), stay in hospital (p=0.142), and indwelling chest tube (p=0.128) was not different between groups. Overall survival after BDG was better in group 2 (p=0.046) [Figure]. In multivariable analysis, maintenance of pulsatility was identified as a risk factor for survival after BDG (p=0.012, HR 4.1 [CI 1.4-12.4]). Conclusions: Maintaining pulsatility at the time of BDG in FSV might be beneficial for pulmonary arterial growth and oxygen saturation without increasing BNP. However, such beneficial effect did not have a positive effect on subsequent Fontan outcome. Attention must be paid to the negative effect of pulsatility on overall post-BDG survival.

Fontan circuit fenestration occlusion with Occlutech patent ductus arteriosus occluder

We present a case of Fontan fenestration closure using an Occlutech patent ductus arteriosus occluder. The patient was diagnosed with tricuspid atresia, pulmonary atresia and secundum ASD at birth. He had a bilateral modified Blalock-Taussig shunt to promote growth of hypoplastic branch pulmonary arteries. He had a bidirectional Glenn Shunt at 11 years of age, and a total cavo-pulmonary connection (TCPC) with a fenestration at 19 years of age. He presented a year later with severe exercise intolerance and cyanosis. Cardiac catheterisation showed hypoxemia, normal pulmonary pressures, patent Fontan circuit and branch pulmonary arteries, and a Fontan circuit-to-right atrium fenestration with right to left shunting. A short shank Occlutech PDA occluder with a waist of 8mm, a pulmonary end of 10mm, an aortic disk of 16mm, and a length of 7mm, was selected to close the fenestration through the transvenous approach. The fenestration achieved complete immediate occlusion with this device.

Palliative reconstruction of right ventricular outflow tract by using femoral vein allograft in a newborn with hypoplastic pulmonary artery and ventricular septal defect: case report

Treating patients with pulmonary atresia and ventricular septal defect, who have hypoplastic native pulmonary arteries, is a challenge for cardiac surgeons. We have reported a case of successful pulmonary bed rehabilitation using a femoral vein allograft in a patient with pulmonary atresia and ventricular septal defect. No similar cases with a detailed description of surgery stages and pulmonary artery development supported by illustrative materials are described both in the literature. The strategy of rehabilitation of the native pulmonary artery bed facilitates antegrade pulmonary blood flow, increases native pulmonary arteries growth, contributes to successful implementation of staged endovascular interventions and allows for complete repair. The technique of “short” cardiopulmonary bypass with induced ventricular fibrillation is a safe and effective option for such patients. This clinical case might be useful in medical practice of pediatric cardiac surgeons involved in the problem of pulmonary artery rehabilitation.Received 4 June 2018. Revised 4 July 2018. Accepted 5 July 2018.Informed consent: The legal representative (infant’s mother) has voluntarily given her written informed consent to use the infant’s medical data obtained in the course of treatment for scientific purposes and for their publication.Funding: The study had no sponsorship.Conflict of interest: Authors declare no conflict of interest.

Impact of a Composite Valved RV-PA Graft After Stage 1 Palliation

The use of a valved right ventricular to pulmonary artery shunt (RVPAS) has been reported by some to improve pulmonary artery growth after stage 1 palliation (S1P). We retrospectively reviewed all patients undergoing an S1P with an RVPAS between January 2013 and May 2017, stratified by RVPAS type: a ring-reinforced polytetrafluoroethylene (PTFE) graft or a composite graft that included a distal valved femoral or saphenous vein homograft. We examined the association of RVPAS type on postoperative hemodynamics, time to reintervention, pulmonary artery growth, and survival. Among 94 infants, 56 (60%) underwent PTFE-only shunt, 24 (25%) underwent femoral vein homograft, and 14 (15%) underwent saphenous vein homograft, and no relevant risk factor differences were found between the groups. Arterial saturation was 2.3% higher (p=0.014) and serum lactic acid was 1.24 mg/dL lower (p= 0.03) in the femoral vein homograft group than in the PTFE-only group, although venous saturation was similar. By 60 days, 50% of patients with saphenous vein homograft had a reintervention compared with 5% with PTFE graft (p < 0.0001) and 12% with femoral vein homograft (p= 0.2 versus PTFE). At the time of stage 2 palliation, no differences were found in pulmonary artery size or growth over time by either echocardiogram or angiography or in the density of aortopulmonary collaterals or degree of tricuspid regurgitation. The 12-month survival was similar between the groups. The use of an interposition femoral vein homograft into the RVPAS may enhance perioperative stability, but it does not substantially improve interstage growth of the pulmonary arteries. Use of saphenous vein homograft is associated with earlier time to reintervention after S1P.

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

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. 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. 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. 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. 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.

Staged Palliation of Cyanotic Obstructive Lesions With a Modified Right Ventricular Outflow Procedure.

Traditional palliation for biventricular cyanotic congenital heart lesions often involves staging with systemic-to-pulmonary arterial shunts to secure pulmonary blood flow (PBF) in the newborn period prior to complete repair. However, shunts may lead to life-threatening events secondary to shunt occlusion or acute coronary steal. They may be associated with morbidity secondary to diastolic runoff, systemic steal and volume loading, and do not provide pulsatile flow which has the potential to promote pulmonary artery (PA) growth. We have alternatively performed modified right ventricular outflow (mRVO) procedures by establishing antegrade right ventricle-to-PA flow. Retrospective review of data on all patients who underwent the mRVO procedure from 2013 to 2016, including anatomy, number of interstage catheterizations, reoperations, intensive care unit admissions, hypercyanotic episodes, interval to complete repair, and mortality. Seventeen nonconsecutive patients included tetralogy of Fallot (n = 14), pulmonary valve stenosis (n = 2), and 1 with pulmonary atresia-intact septum; 14 had significant branch PA stenosis. Median age of first mRVO procedure was 14 days (range 5-193), and median duration of follow-up was 15.3 months (range 4-47 months). No patients had post-palliation acute hypercyanotic episodes. Nine were admitted to the ICU for persistent interstage hypoxemia, 7 of whom required reintervention prior to complete repair, which was achieved in 11 patients. Two late deaths unrelated to mRVO occurred. The mRVO procedure is a potential option with satisfactory results. It avoids potential shunt-related sudden death. The physiology of the mRVO palliation may provide unique benefits by providing antegrade pulsatile PBF, facilitates catheter interventions, and avoids branch PA distortion and stenosis.

Stenting the complex patent ductus arteriosus in tetralogy of Fallot with pulmonary atresia: challenges and outcomes.

Patent ductus arteriosus (PDA) stenting has gained acceptance for palliation in cyanotic congenital heart disease. The PDA in tetralogy of Fallot with pulmonary atresia (ToF-PA) arises, in the left aortic arch, from underneath the arch and connects to the proximal left pulmonary artery, often resulting in stenosis. The PDA is usually elongated and tortuous, making stent implantation challenging. Shorter duration of palliation, aggravation of branch pulmonary artery stenosis resulting in poor growth and difficulty at surgery makes ductal stenting controversial. Access via the carotid and axillary artery reduces complexity of the procedure and improves success, with recent data demonstrating good pulmonary artery growth. Advances in bioresorbable stents offer future promise and will likely resolve some controversies surrounding PDA stenting in ToF-PA.

Stenting of the Right Ventricular Outflow Tract Promotes Better Pulmonary Arterial Growth Compared With Modified Blalock-Taussig Shunt Palliation in Tetralogy of Fallot–Type Lesions

ObjectivesThis study sought to compare pulmonary arterial (PA) growth during palliation after right ventricular outflow tract (RVOT) stenting versus modified Blalock-Taussig shunt (mBTS) in patients coming forward for complete repair of tetralogy of Fallot–type lesions. BackgroundRVOT stenting is a recent alternative to mBTS in the initial palliation of selected patients with Fallot-type lesions. MethodsThis was a retrospective, single-center study of nonrandomized, consecutive palliated Fallot patients over a 10-year period. Differential left PA (LPA) and right PA (RPA) growth was assessed by serial echocardiograms in 67 patients after mBTS (n = 28) or RVOT stent (n = 39). Statistical data analysis was performed using mixed model analysis. ResultsRPA z-scores in the mBTS group improved from median −2.41 (interquartile range [IQR]: −2.97 to −1.32) to −1.13 (IQR: −1.68 to −0.59). LPA z-scores improved from −1.89 (IQR: −2.33 to −1.12) to −0.32 (IQR: −0.88 to −0.05). In the RVOT stenting group RPA z-scores improved from −2.28 (IQR: −3.28 to −1.82) to −0.72 (IQR: −1.27 to +0.48), and LPA z-scores from −2.08 (IQR: −2.90 to −0.61) to −0.05 (IQR: −0.88 to +0.48). Mixed model analysis showed significantly better RPA and LPA growth after RVOT stenting. The benefit of RVOT stenting versus mBTS was 0.599 z-scores for the LPA and 0.749 z-scores for the RPA. Rise in oxygen saturations was greater with RVOT stenting (p = 0.012). Median time to complete repair was shorter in the RVOT stent group (227 [142 to 328] days) compared with the mBTS group (439 [300 to 529] days; p < 0.0003). ConclusionsRVOT stenting promotes better pulmonary arterial growth and oxygen saturations compared with mBTS in the initial palliation of Fallot-type lesions.

Promoting Pulmonary Arterial Growth via Right Ventricle-to-Pulmonary Artery Connection in Children With Pulmonary Atresia, Ventricular Septal Defect, and Hypoplastic Pulmonary Arteries.

Complete repair of pulmonary atresia (PA) ventricular septal defect (VSD) with hypoplastic or absent native pulmonary arteries, often with major aortopulmonary collateral arteries (MAPCAs), involves construction of an adequate sized pulmonary arterial tree. We report our results with a previously described staged strategy using initial right ventricle (RV)-to-reconstructed pulmonary arterial tree (RV-PA) connection to promote pulmonary arterial growth and facilitate later ventricular septation. We retrospectively reviewed data for all patients (N = 10) with initial echocardiographic diagnosis of PA-VSD and hypoplastic pulmonary arteries operated in our center from October 2008 to August 2016. Pulmonary arterial vessel size measured on preoperative and postoperative angiography was used to calculate Nakata index. Seven patients had PA-VSD, three had virtual PA-VSD, and seven had MAPCAs. All underwent creation of RV-PA connection at a median age of 7.5 days and weight 3.6 kg. Eight patients had RV-PA conduits, two had a transannular patches, and seven had major pulmonary artery reconstruction simultaneously. There were no deaths or serious morbidity; one conduit required revision prior to complete repair. Complete repair with ventricular septation and RV pressure less than half systemic was achieved in all patients at a median age of 239 days. Nakata index in neonatal period was 54 mm2/m2 (range 15-144 mm2/m2) and at time of septation 184 mm2/m2 (range 56-510 mm2/m2; P = .004). Growth rates of right and left branch pulmonary arteries were similar. The 10 patients underwent 28 catheterizations with 13 interventions in 8 patients prior to full repair. Early palliative RV-PA connection promotes pulmonary arterial growth and facilitates eventual full repair with VSD closure with low RV pressure and operative risk.

Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation.

To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation. A retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation. A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations. Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Outcomes of palliative right ventricle to pulmonary artery connection for pulmonary atresia with ventricular septal defect.

To determine the early, intermediate and long-term outcomes of pulmonary atresia with ventricular septal defect (PA/VSD) Types I, II and III initially palliated by a right ventricle to pulmonary artery (RVPA) connection. We performed a retrospective study from 2000 to 2014 that included 109 patients with PA/VSD who had undergone an RVPA connection (tetralogy of Fallot and PA/VSD Type IV excluded). The end-points of this strategy were adequate pulmonary artery tree post-palliation, second palliation, biventricular repair, right ventricular pressure post-biventricular repair and late reoperation. Mean follow-up was 5.4 years (1 day to 14-78 years). Early mortality after an RVPA connection was 2.7% (3 of 109). The interstage mortality rate was 6.6% (7 of 106). Eighty-four (77%) patients had a biventricular repair and 8 patients (7%) are awaiting repair. Overall survival was 90% at 1 year and 81% at 10 years. The RVPA connection allowed significant growth of the native pulmonary artery with a Nakata index of 101 mm2/m2 before the RVPA connection and 274 mm2/m2 after (P = 0.001). Twenty-nine reinterventions for restrictive pulmonary blood flow have been done (9 before 2 months and 20 after 2 months). Of the 84 patients who had a repair, 22 patients (26%) initially had a right ventricular pressure greater than 40 mmHg. Twenty-eight patients (33%) required late reoperation. Hospital deaths after the RVPA connection were low. The procedure allowed good growth of the native pulmonary artery. Biventricular repair was possible in a large number of cases. The late morbidity rate remains significant. Early reinterventions could be avoided by appropriate calibration. This technique appears to be suitable for any type of PA/VSD with central pulmonary arteries.

Bilateral bidirectional Glenn: outcome of off-pump technique.

Off-pump bilateral bidirectional Glenn (b-BDG) poses a surgical challenge and may add complexity to the postoperative outcome especially regarding uniformity of the anastomosis and central pulmonary artery growth. Herein, we report early- and mid-term outcomes after off-pump b-BDG without using superior vena cava decompression techniques. Ninety-seven consecutive patients, between 2009 and 2014, were included in this prospective study. All patients had complete pre- and postoperative clinical and detailed neurological assessments. Diagnosis and follow-up were done by echocardiography and cardiac catheterization for assessment of pulmonary artery anatomically and haemodynamically. Median follow-up period was 3.5 years. Perioperative variables, clinical outcome, morbidity, mortality and follow-up data were recorded. Hypoplastic right ventricle was present in 52 cases (53.6%) and hypoplastic left ventricle was present in 45 cases (46.4%). Mean superior vena cava pressure on clamping was 21.49 ± 3.04 mmHg. Mean total clamping time was 23.11 ± 3.44 min. Mean oxygen saturation increased from preoperative 69.22 ± 6.01% to 83.66 ± 3.97% after b-BDG construction (P-value ≤ 0.0001). The Nakata index increased from 288.47 ± 28.66 mm2/m2 to 303.64 ± 26.85mm2/m2 on follow-up (P-value ≤ 0.05). In-hospital mortality was 4 patients (4.1%) due to low-cardiac output. There were chylothorax in 9 patients (9.3%) and convulsions in 4 patients (4.1%) who were treated conservatively. Off-pump b-BDG can be conducted safely, with a uniform anastomosis that allows a good central pulmonary artery growth for subsequent Fontan completion. Moreover, avoiding the use of cardiopulmonary bypass is more economic and less hazardous.

6 Initial palliation of tetralogy of fallot: comparison between BT shunt and RVOT stent

Background Neonatal repair of symptomatic infants with Fallot-type(ToF) lesions remains the exception in the UK. Initial palliation can be achieved by creation of a BT shunt, or RVOT stenting. Aims To compare the outcome of BTS and RVOT stent in the palliation of TOF. Methods 10 year retrospective review of the outcome of 101 ToF patients who required initial palliation (RVOT stent n=60; BTS n=41) prior to complete repair. Detailed assessment of PA growth in patients with comparable underlying anatomy. Results In the RVOT stent group vs the BT shunt group, there was a lower PICU admission rate (22% vs 100%) (p Conclusions RVOT stenting is a safe and effective palliation in the initial treatment of infants with symptomatic Fallot-type lesions and promotes pulmonary artery growth.

Femoral Vein Homograft as Right Ventricle to Pulmonary Artery Conduit in Stage 1 Norwood Operation

The polytetrafluoroethylene tube used as right ventricle to pulmonary artery conduit in the stage 1 Norwood operation is associated with risks of suboptimal branch pulmonary artery growth, thrombosis, free insufficiency, and long-term right ventricular dysfunction. Our experience with use of valved femoral vein homograft as right ventricle to pulmonary artery conduit is described. Between June 2012 and December 2015, 15 neonates with hypoplastic left heart syndrome or complex single ventricle underwent stage 1 Norwood operation with valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit. The median age at surgery was 3 days and the mean weight was 3 kg. The size of the femoral vein homograft was 5 mm in 8 patients and 6 mm in 7 patients. There was no hospital or interstage mortality. Fourteen patients underwent Glenn operation, and 6 have undergone Fontan operation to date. The median Nakata index at pre-Glenn catheterization was 262 mm2/m2 (interquartile range: 121 to 422 mm2/m2). No patient had thrombosis of conduit. Most femoral vein conduits remained competent in the first month after stage 1 Norwood operation, although most became incompetent by 3 months. Catheter intervention on the conduit was necessary in 7 patients. Right ventricular function was preserved in most patients at follow-up. The use of femoral vein homograft as right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function. Balloon dilation of the conduit may be necessary during the interstage period.

The blalock and taussig shunt revisited.

The systemic to pulmonary artery shunts are done as palliative procedures for cyanotic congenital heart diseases ranging from simple tetralogy of Fallots (TOFs)/pulmonary atresia (PA) to complex univentricular hearts. They allow growth of pulmonary arteries and maintain regulated blood flow to the lungs till a proper age and body weight suitable for definitive corrective repair is reached. We have reviewed the BT shunt with its anaesthtic considerations and management of associated complications.

手術時月齢因子からみた Blalock-Taussig シャント手術後,遠隔期の肺動脈発育について

手術時月齢因子からみた Blalock-Taussig シャント手術後,遠隔期の肺動脈発育について

Right Ventricular Outflow Tract Stenting in Tetralogy of Fallot Infants With Risk Factors for Early Primary Repair.

Tetralogy of Fallot with cyanosis requiring surgical repair in early infancy reflects poor anatomy and is associated with more clinical instability and longer hospitalization than those who can be electively repaired later. We bridged symptomatic infants with risk factors for early primary repair by right ventricular outflow tract stenting (stent). Four groups of tetralogy of Fallot with confluent central pulmonary arteries were studied: stent group (n=42), primary repair (aged <3 months) with pulmonary stenosis (early-PS group; n=44), primary repair (aged <3 months) with pulmonary atresia (early-PA group; n=49), and primary repair between 3 and 11 months of age (surg>3mo group; n=45). Stent patients had the smallest pulmonary arteries with a median (95% credible intervals) Nakata index (mm2/m2) of 79 (66-85) compared with the early-PA 139 (129-154), early-PS 136 (121-153), and surg>3mo 167 (153-200) groups. Only stent infants required unifocalization of aortopulmonary collaterals (17%). Stent and early-PA infants had younger age and lower weight than early-PS infants. Stent infants had the most multiple comorbidities. Stenting allowed deferral of complete surgical repair to an age (6 months), weight (6.3 [5.8-7.0] kg), and Nakata index (147 [132-165]) similar to the low-risk surg>3mo group. The 3 early treatment groups had similar intensive care unit/hospital stays and high reintervention rates in the first 12 months after repair, compared with the surg>3mo group. Right ventricular outflow tract stenting of symptomatic tetralogy of Fallot with poor anatomy (small pulmonary arteries) and adverse factors (multiple comorbidities, low weight) relieves cyanosis and defers surgical repair. This allowed pulmonary arterial and somatic growth with clinical results comparable to early surgical repair in more favorable patients.