Systemic-pulmonary Artery Shunt Research Articles

Bridge to Surgery with Pulmonary Valve Perforation and Right Ventricular Outflow Tract Stenting in an Infant with PA-VSD

Pulmonary atresia (PA) with ventricular septal defect (VSD) is a rare congenital heart disease. Blood flow to pulmonary arteries is provided by patent ductus arteriosus or major aorto-pulmonary collateral arteries (MAPCAs). Palliative interventions are required to maintain the blood supply to the pulmonary arteries in order to achieve for the complete surgical repair. In this case report, we present a patient who underwent pulmonary valve perforation and right ventricular outflow tract (RVOT) stenting as an alternative to a systemic-pulmonary artery shunt (SPS). Subsequently, surgical repair was performed ten months later.

Transcatheter Ductal Stents Versus Surgical Systemic-Pulmonary Artery Shunts in Neonates With Congenital Heart Disease With Ductal-Dependent Pulmonary Blood Flow: Trends and Associated Outcomes From the Pediatric Health Information System Database.

Background Surgical systemic-to-pulmonary artery shunts have been the standard approach to establish stable pulmonary blood flow in neonates with congenital heart disease with ductal-dependent pulmonary blood flow. More recently, transcatheter ductal stents have been performed as an alternative, less invasive intervention. We aimed to characterize trends in the utilization of surgical shunts versus ductal stents and compare associated outcomes. Methods and Results Using data from the Pediatric Health Information System, we retrospectively analyzed neonates with congenital heart disease with ductal-dependent pulmonary blood flow who underwent surgical shunt or ductal stent placement between January 2016 and December 2021. Patients were identified by International Classification of Diseases, Tenth Revision (ICD-10) diagnosis and procedure codes. The primary outcome was length of hospital stay. Secondary outcomes were reintervention risk and adjusted hospital costs. Of 936 patients included, 65.2% underwent a surgical shunt over the 6-year period. The proportion who underwent ductal stenting increased from 19% to 53.4% from 2016 to 2021. The median adjusted difference in postintervention length of hospital stay was 11 days greater for the surgical shunt cohort (95% CI, 7.2-14.8; P<0.001). The adjusted reintervention risks within 3 (odds ratio [OR], 3.37 [95% CI, 1.91-5.95], P<0.001) and 6 months (OR, 2.43 [95% CI, 1.62-3.64], P<0.001) were significantly greater in the ductal stent group. Median adjusted index hospital costs were $198 300 ($11 6400-$340 000) versus $120 400 ($81 800-$192 400) for the surgical shunt and ductal stent cohorts, respectively (P<0.001). Conclusions Ductal stenting has become an increasingly utilized palliative approach to secure pulmonary blood flow in neonates with congenital heart disease with ductal-dependent pulmonary blood flow in the United States. Ductal stenting is associated with decreased length of hospital stay and reduced overall cost for the index hospitalization but with a greater reintervention risk than surgical shunting.

Palliative Procedures for Congenital Heart Disease: Imaging Findings and Complications

Palliative procedures are performed for congenital heart diseases that are not amenable for definitive surgical procedures or as a component of hybrid procedures along with transcatheter interventions. Multimodality imaging plays an important role in the follow-up of these palliative procedures, mainly for the timely detection of complications and for planning any subsequent palliative or definitive procedure. Echocardiography is the first-line imaging modality, with CT and MRI used as complementary techniques in indeterminate cases. MRI provides anatomic, functional, flow, and tissue characterization information. CT is performed for the evaluation of vascular anatomy and when MRI cannot be performed due to contraindications, challenges, or artifacts. The modified Blalock-Taussig shunt procedure is the most common systemic-pulmonary artery (PA) shunt procedure, with thrombus being the most serious complication. Other complications of systemic-PA shunts include shunt stenosis, infection, pulmonary overcirculation, and cardiac failure. The Glenn shunt procedure is the second stage of palliation in single ventricle physiology, with thrombus, stenosis, superior vena cava syndrome, and infection being the common complications. The Fontan shunt procedure is the third stage of palliation in single ventricle physiology. Complications can be cardiovascular (heart failure, valve regurgitation, thromboembolism, shunt stenosis, arteriovenous malformation), venolymphatic (collaterals, protein-losing enteropathy, plastic bronchitis), or hepatic (congestion, cirrhosis, portal hypertension). PA banding is used to decrease pulmonary flow or to train the systemic ventricle. Complications include stenosis, thrombus, erosion, pseudoaneurysm, and subaortic obstruction. Atrial septostomy and atrial switch procedures are performed for increasing intracardiac mixing. Complications of atrial septostomy can be mechanical, traumatic, embolic, or electrical. Complications of the atrial switch procedure include baffle stenosis, baffle leak, and systemic ventricle failure. The authors review the role of multimodality imaging in the evaluation of these palliative procedures. © RSNA, 2023 See the invited commentary by Bardo and Popescu in this issue. Quiz questions for this article are available through the Online Learning Center.

Treatment of massive hemoptysis after thoracic aortic aneurysm repair

BackgroundMassive hemoptysis after thoracic aortic aneurysm (TAA) repair is a rare but potentially lethal condition. Endovascular management is a challenging treatment option due to the complexity of culprit vessel access.Case presentationAn 81-year-old woman was referred to our hospital with massive hemoptysis. She had a history of graft replacement and thoracic endovascular aortic repair (TEVAR) for dissecting TAA. Computed tomography (CT) showed massive atelectasis with hematoma in the left lower lung lobe adjacent to the descending aortic aneurysm treated with TEVAR. Contrast-enhanced CT revealed a pseudoaneurysm and proliferation of abnormal vessels at the peripheral side of the left pulmonary ligament artery (PLA) in the atelectasis. The PLA continued to the right subscapular artery via a complex collateral pathway. Diagnostic angiography of the right subcapsular artery revealed a pseudoaneurysm and abnormal vessels at the peripheral side of the left PLA with a systemic-pulmonary artery shunt. Transcatheter arterial embolization (TAE) for the left PLA via the collateral pathway with N-butyl cyanoacrylate achieved complete embolization. The patient’s hemoptysis was controlled and she was discharged.ConclusionsHere we presented a case of massive hemoptysis due to PLA disruption that occurred after TAA repair. TAE via a complex collateral pathway is a feasible and effective treatment for hemoptysis, even in patients who have undergone surgical or endovascular TAA repair.

Ductus Arteriosus Stent Compared with Surgical Shunt for Infants with Ductal-Dependent Pulmonary Blood Flow: A Systematic Review and Meta-Analysis

The aim of this study was to perform a systematic review and meta-analysis to evaluate the safety and efficacy of ductus arteriosus stent (DAS) compared with surgical systemic-pulmonary artery shunt (SPS) in patients with ductal-dependent pulmonary blood flow. A literature search was conducted in PubMed, Embase, and the Cochrane Library databases from their inception to December 2020. Two reviewers independently screened the articles, evaluated the quality of the articles, and collected the data. Meta-analyses were conducted using fixed and random effects models. We used the I-square (I2 ) test to examine heterogeneity and the funnel plot Egger’s test was used to test for publication bias. We analyzed nine studies including 842 patients were included in the present study (DAS: n = 295; SPS: n = 547). There was a benefit in favor of DAS group for medium-term mortality (RR, 0.63; 95% CI, [0.40, 0.99]; P = 0.91, I2 = 0%). DAS group demonstrated a reduced risk for complications compared with SPS (RR, 0.46; 95% CI, [0.29, 0.72]; P = 0.78, I2 = 0%). There was an increased risk for unplanned reintervention for DAS (RR, 1.77; 95% CI, [1.42, 2.20]; P = 0.61, I2 = 0%). DAS demonstrated shorter mean intensive care unit length of stay (MD, –5.12; 95% CI, [–7.33, –2.91]; P = 0.005, I2 = 76%). There was also demonstrated higher postprocedure oxygen saturation for SPS over DAS (MD, 1.78; 95% CI, [0.92, 2.64]; P = 0.46, I2 = 0%). There was no difference between the two groups in terms of mortality within 30 days, Nakata Index, and hospital length of stay. Conclusions: In terms of initial palliative surgical in the ductal-dependent pulmonary blood flow, DAS demonstrated a lower risk of medium-term mortality, lower risk of complications, higher risk of unplanned reintervention, shorter ICU length of stay, and higher postprocedure oxygen saturation compared with SPS.

Prevalence and Risk Factors for Pericardial Effusions Requiring Readmission After Pediatric Cardiac Surgery.

Pericardial effusion (PE) may require readmission after cardiac surgery and has been associated with postoperative morbidity and mortality. We sought to identify the prevalence and risk factors for postoperative PE requiring readmission in children. A retrospective analysis of the Pediatric Health Information System database was performed between January 1, 2003, and September 30, 2014. All patients ≤18years old who underwent cardiac surgery were identified by ICD-9 codes. Those readmitted within 1year with an ICD-9 code for PE were identified. Logistic regression analysis was performed to determine risk factors for PE readmissions. Of the 142,633 surgical admissions, 1535 (1.1%) were readmitted with PE. In multivariable analysis, older age at the initial surgical admission [odds ratio (OR) 1.17, p<0.001], trisomy 21 (OR 1.24, p=0.015), geographic region (OR 1.33-1.48, p≤0.001), and specific surgical procedures [heart transplant (OR 1.82, p<0.001), systemic-pulmonary artery shunt (OR 2.23, p<0.001), and atrial septal defect surgical repair (OR 1.34, p<0.001)] were independent risk factors for readmission with PE. Of readmitted patients, 44.2% underwent an interventional PE procedure. Factors associated with interventions included shorter length of stay (LOS) for the initial surgical admission (OR 0.85, p=0.008), longer LOS for the readmission (OR 1.37, p<0.001), and atrial septal defect surgery (OR 1.40, p=0.005). In this administrative database of children undergoing cardiac surgery, readmissions for PE occurred after 1.1% of cardiac surgery admissions. The risk factors identified for readmissions and interventions may allow for improved risk stratification, family counseling, and earlier recognition of PE for children undergoing cardiac surgery.

Long-term outcome after treatment of pulmonary atresia with ventricular septal defect: nationwide study of 109 patients born in 1970-2007.

Treatment of pulmonary atresia with ventricular septal defect (PA + VSD) has evolved during recent decades, but it still remains challenging. This study evaluated 41-year experience of outcome, survival and treatment of PA + VSD patients. Patient records and angiograms of 109 patients with PA + VSD born in Finland between 1970 and 2007, and treated at the Children's Hospital, Helsinki University Central Hospital, were retrospectively analysed in this nationwide study. Of the 109 patients, 66 (61%) had simple PA + VSD without major aortopulmonary collateral arteries (MAPCAs). Although we observed no difference in overall survival between those with or without MAPCAs, the patients without MAPCAs had better probability to achieve repair (64 vs 28%, P < 0.0003). Only 3 patients were treated by compassionate care. Overall survival was affected by the size of true central pulmonary arteries on the first angiogram (P = 0.001) and whether repair was achieved (P < 0.0001). After successful repair, the survival rate was 93% at 1 year, 91% from the second year, and functional capacity as assessed by New York Heart Association (NYHA) I-II remained in 85% of patients alive at the end of follow-up. Palliated patients at 1, 5, 10 and 20 years of age had Kaplan-Meier estimated survival rates of 55, 42, 34 and 20%, respectively. Patients who underwent repair attempts but were left palliated with right ventricle (RV)-pulmonary artery connection and septal fenestration had better survival than the rest of the palliated patients (P = 0.001). Further, the McGoon index improved after implementation of a systemic-pulmonary artery shunt in the overall PA + VSD population (P < 0.0001). These findings show that achievement of repair and initial size of true central pulmonary arteries affect survival of patients with PA + VSD. Although the overall survival of patients with MAPCAs showed no difference compared with simple PA + VSD patients, they had a higher risk of remaining palliated. However, palliative surgery may have a role in treatment of PA + VSD because the size of pulmonary arteries increased after placement of systemic-pulmonary artery shunt. In addition, subtotal repair by a RV-pulmonary artery connection and septal fenestration improved survival over extracardiac palliation.

Abstract 12635: Nationwide Long-term Follow-up of Pulmonary Atresia With Ventricular Septal Defect

Introduction: The naturally poor survival of pulmonary atresia with ventricular septal defect (PA+VSD) has improved due to evolved perioperative and surgical treatment. Studies including PA+VSD patients, both with and without major aortopulmonary collateral arteries (MAPCAs), with extensive follow-up are scarce. This nationwide study aimed to investigate survival and surgical treatment in PA+VSD patients with and without MAPCAs. Methods: Study comprised 109 PA+VSD patients born in Finland between 1970 and 2007. We reviewed retrospectively medical records and operative reports through December 2011, as well as first available angiograms and preoperative angiograms prior to repair attempt. Results: The median follow-up time for the total study population, including also patients who died during the follow-up, was 11.4 years (IQR 0.8 - 21.1). The incidence of PA+VSD, which could be determined reliably from 1995 to 2007, was 6.1 per 100 000 live births. Although the patients with (n = 43) or without MAPCAs (n = 66) showed no difference in survival (p = 0.74), the patients without MAPCAs had better probability to achieve repair (64% vs. 28%, p &lt; 0.0001). The bigger size of true central pulmonary arteries assessed by McGoon index at first angiogram [HR 0.66 (CI95% 0.49 - 0.88) per 0.5 McGoon index units, p = 0.006] and achievement of repair [HR 0.07 (CI95% 0.03 - 0.17), p &lt; 0.0001] improved the overall survival. After successful repair survival was 93% at 1 year and 91% from 2 years on. Palliated patients, instead, had survival at 1, 5, 10, and 20 years of age of 55%, 42%, 34%, and 20% respectively. However, patients with right ventricle - pulmonary artery connection and septal fenestration had better survival than rest of the palliated patients (p = 0.001). Palliation with a systemic-pulmonary artery shunt increased McGoon index by 41% (p &lt; 0.0001). Conclusions: The patients with MAPCAs had higher risk to remain palliated than patients without, although their survival was similar. Survival of PA+VSD was influenced by the initial size of true central pulmonary arteries and whether repair was achieved. Although palliative procedures may not improve the final outcome of PA+VSD, palliative surgery may have a role in its treatment.

Systemic-pulmonary artery shunts in infants: modified Blalock-Taussig and central shunt procedures.

Access is gained through a midline sternotomy, the thymus partially excised and the superior part of the pericardium is opened. The innominate vein is retracted and the innominate artery is mobilized up to the bifurcation. The aorta is retracted to the left, the superior vena cavae to the right and the right atrial appendage inferiorly. The adventitia around the right pulmonary artery (PA) is dissected, taking care to incise the bulky pericardial reflection between the superior vena cavae and the trachea. Heparin is administrated. An occlusive clamp is applied to the right PA to test for haemodynamic tolerance prior to proceeding with the interposition of a suitable size artificial vascular prosthesis, based on the weight of the patient, between the innominate artery, or proximal subclavian artery and the right PA. Alternatively, if a sufficient main PA is present and adequate flow from a patent ductus arteriosus an end-to-side interposition shunt may be constructed between the ascending aorta and the main PA, provided the patient is stable with the test occlusion of the main PA. The management of the patent arterial ductus depends on whether or not there is forward flow through the PA.

Bronchial and Nonbronchial Systemic Artery Embolization in Management of Hemoptysis: Experience with 348 Patients

Background. We aimed to report our experience with bronchial artery embolization (BAE) in the management of moderate recurrent and/or life-threatening hemoptysis. Methods. We evaluated the demographics, clinical presentation, radiographic studies, short- and long-term efficacy, and complications in patients Who underwent BAE, at a tertiary university hospital, from 2003 to 2012. Results. Three hundred forty-one patients underwent BAE for the management of moderate recurrent or life-threatening hemoptysis. Pulmonary TB and bronchiectasis were the most common etiologies for hemoptysis in our locality. The most common angiographic signs for hemoptysis were hypervascularity and systemic-pulmonary artery shunt. BAE was successful in controlling hemoptysis immediately in 95% of patients and at 1 month in 90% of patients. Recurrence of hemoptysis was observed in 9.6% of patients, and reembolization was indicated in 85% of those cases. Complications of BAE were self-limited acute and subacute complications, while chronic complications were not recorded during this study. Conclusions. TB and bronchiectasis are the commonest etiologies for moderate recurrent or life-threatening hemoptysis in our locality. Hypervascular lesions from the bronchial arteries and nonbronchial systemic arteries represented the major vascular abnormalities. Bronchial and nonbronchial systemic artery embolizations were effective to control both acute and chronic hemoptyses, with no serious complications.

Role of Systemic to Pulmonary Artery Shunt after Cavopulmonary Anastomosis

Superior cavopulmonary anastomosis and total cavopulmonary anastomosis are the procedures of choice for the management of patients with a functionally univentricular heart. We review the various indications, sites, advantages, and complications of a systemic to pulmonary artery shunt after the creation of superior cavopulmonary anastomosis. Systemic pulmonary artery shunt may be useful as a palliative strategy in patients who have hypoxemia and completion of total cavopulmonary anastomosis is not feasible.

Clinical results of combined palliative procedures for cyanotic congenital heart defects with intractable hypoplasia of pulmonary arteries

Background Congenital heart defects with intractable hypoplasia of the pulmonary arteries without intercourse or with intercourse stenosis is unsuitable for surgical correction or regular palliative procedures. We reported our experience with combined palliative procedures for congenital heart defects with intractable hypoplasia pulmonary arteries. Methods From 2001 to 2012, a total of 41 patients with cyanotic congenital heart defects and intractable hypoplasia of the pulmonary arteries underwent surgical procedures. From among them, 31 patients had pulmonary atresia with ventricular septal defect (VSD) and the other 10 cases had complicated congenital heart defects with pulmonary stenosis. Different kinds of palliative procedures were performed according to the morphology of the right and left pulmonary arteries in every patient. If the pulmonary artery was well developed, a Glenn procedure was performed. A modified Blalock-Taussig shunt or modified Waterston shunt was performed if pulmonary arteries were hypoplastic. If the pulmonary arteries were severely hypoplastic, a Melbourne shunt was performed. Systemic pulmonary artery shunts were performed bilaterally in 25 cases. A systemic-pulmonary shunt was performed on one side and a Glenn procedure was performed contralaterally in 16 cases. Major aortopulmonary collateral arteries were unifocalized in six cases, ligated in two cases and interventionally embolized in two cases. There was one early death because of cardiac arrest and the hospital mortality was 2.4%. Results Five patients suffered from postoperative low cardiac output syndrome, three had perfusion of the lungs, and two pulmonary infections. Systemic pulmonary shunts were repeated after the original operation in three cases due to the occlusion of conduits. The mean follow-up time was 25 months. The pre- and the post-operation left pulmonary indices were (8.13±3.68) vs. (14.9±6.21) mm2/m2. The pre- and post-operation right pulmonary indices were (12.7±8.13) vs. (17.7±7.78) mm2/m2. The pre- and post-operational pulmonary indices were (20.87±9.43) vs. (32.6±11.7) mm2/m2. They were all significantly increased (P &lt;0.001). The diameter of the pulmonary artery increased after the modified Blalock-Taussig shunt ((5.51±0.94) mm2/m2 pre-operation vs. (7.01±1.97) mm2/m2 post-operation), the modified Waterston shunt ((5.70±3.96) mm2/m2 pre-operation vs. (9.17±3.62) mm2/m2 post-operation) and the Melbourne shunt ((2.17±0.41) mm2/m2 pre-operation vs. (7.35±2.49) mm2/m2 post-operation) (all P &lt;0.05). Bilateral pulmonary arteries developed well as compared to their pre-operation development. Hemoglobin decreased from (194±27) to (174±24) g/L (P &lt;0.05) and peripheral oxygen saturation increased from (65±11)% to (84±6)% (P &lt;0.001). During the follow-up of 27 to 49 months, ultimate complete repair was performed in four cases and one patient underwent a Glenn procedure. Conclusions The procedures should be considered on a case to case basis in patients having hypoplasia of the pulmonary arteries with cyanotic congenital heart defects. Combined palliative operations could be an adequate strategic treatment.

Balloon Angioplasty and Stent Implantation Performed Through Systemic-to-Pulmonary Artery Shunts in Infants and Neonates

Branch pulmonary artery stenosis (BPAS) in the setting of systemic-pulmonary artery shunts (SPS) may result in significant sequelae. Limited information exists regarding the safety and efficacy of pulmonary artery balloon angioplasty and stent implantation via SPS in neonates and infants. This study aimed to examine the feasibility, safety, and efficacy of balloon angioplasty/stent implantation for BPAS performed via SPS in neonates and infants. A single-center retrospective analysis of all patients weighing 10 kg or less who underwent angioplasty for BPAS via SPS was performed. Systemic oxygen saturations and vessel diameter before, during, and after the procedure were compared. Between July 1996 and February 2008, 15 patients underwent 20 catheterizations for the treatment of 27 BPAS via SPS. The patients had a mean weight of 5.6 kg (range, 2.6-10 kg) and a mean age of 7.6 months (range, 7 days to 33 months). The SPS diameter ranged between 2 and 5 mm (median, 3.5 mm). Angioplasty was performed for all 27 lesions, and an additional stent was placed in 5 of these. The average lesion diameter increased from 2.3 ± 1.5 to 4.7 ± 1.7 mm (p < 0.05), and 25 (93 %) of the 27 lesions met the predetermined criteria for success. Systemic oxygen saturation increased from 73 ± 9.5 % to 82 ± 6.8 % immediately after intervention and was 83 ± 7.9 % at discharge (p < 0.05). There were no instances of shunt thrombosis. Two patients experienced transient hypotension during the procedure. No procedural deaths occurred. The study findings suggest that balloon angioplasty or stent implantation performed via SPS appears to be safe and effective treatment for BPAS in neonates and infants.

Computer aided approximation of flow rate through systemic-pulmonary arterial shunts (SPAS)

The discrimination of flow rates through bronchial arteries that are affected by pathological SPAS today still happens solely qualitatively. A reproducible quantification of flow rates, however, would enable the comprehension of phenomena like the intensified shunt perfusion seen in cases of chronic inflammations or the characterization of SPAS that may cause cardiovascular problems. A computational program is developed, that allows the modeling of individual bronchial arteries on the basis of the information provided by angiography. Angiographic images are available from the standard clinical assessment of SPAS. The flow through continuous and geometrically measurable vessel segments and SPAS is given by the law of Hagen-Poiseuille. The discharge through healthy branches is calculated by means of allometric scaling laws. The simulation results are verified by flow experiments in artificial vessel networks made of glass and PE tubing. The experimental set-up mimics realistic, pulsating pressure and flow conditions. When applied to the artificial vessel networks, the model described herein provides results for the volumetric flow rate that differ from values measured in laboratory experiments by <6%. The computer model is also applied to real angiographic images. Due to inaccuracies during the deduction of the geometry and due to necessary simplifications of the model, we expect significant deviations between calculated and real flow rates in bronchial systems. Nevertheless, the presented method enables the physician to objectively estimate the order of magnitude of volumetric flow through individual SPAS fairly independently from his experience and without the need of measurements additional to the mandatory angiography.

Two-Day Control of Pulmonary Blood Flow with an Adjustable Systemic-Pulmonary Artery Shunt

Our laboratory has developed an adjustable systemic-pulmonary artery shunt (AS) to provide improved control of pulmonary blood flow (PBF) after neonatal palliation of hypoplastic left heart syndrome (HLHS). Six piglets of 6-10 kg underwent left thoracotomy and placement of a 3.5 mm polytetrafluoroethylene (PTFE) shunt from the left subclavian artery to the left pulmonary artery (LPA). The LPA was ligated at its origin. An AS was placed on the PTFE graft after both anastomoses had been performed. A flow probe was placed on the LPA distal to the shunt insertion. The AS was adjusted every 2 hours (0.1 mm increments over 18 minutes) from fully open to an estimated 60% flow reduction throughout the 44-hour test period, similar to delayed sternal closure (DSC). At any shunt setting, standard deviations of normalized blood flow in each piglet were ranged from 1.34% to 8.05% indicating consistent and stable relationship between shunt setting and flow over the DSC. These data lend strong evidence that the device would perform successfully in a human infant during the DSC. Clinical trials are necessary to determine whether mechanical control of PBF results in improved clinical outcomes.

Reporting adverse events in a surgical trial for complex congenital heart disease: The Pediatric Heart Network experience

The purpose of this analysis was to evaluate a novel strategy for reporting adverse events in the Pediatric Heart Network's randomized surgical trial of systemic-pulmonary artery shunt versus right ventricle-pulmonary artery conduit in infants with hypoplastic left heart syndrome. The strategy was developed to align the reporting process with the needs of a surgical trial while maintaining participant safety. Adverse event reporting was analyzed for 2 groups of study subjects: those randomized to a trial arm during a period in which a standard adverse event reporting system was used (period 1) and those randomized after institution of a system that focused serious adverse event reporting on 6 sentinel events (period 2). The analysis encompassed the period from randomization (Norwood surgery) to hospital discharge from stage II surgery. Adverse event rates were compared using a Poisson regression model for the number of events per subject. From period 1 to period 2, the rate of serious adverse events requiring expedited reporting decreased as expected (0.42 vs 0.14/subject/month of follow-up; P < .001). Subjects with a serious (sentinel) adverse event in period 2 had a significantly higher rate of death and cardiac transplantation. The new adverse event reporting system successfully targeted subjects at highest risk, while decreasing the administrative burden associated with adverse event reports. This methodology may be of benefit in trials evaluating surgical or device-based interventions and in critically ill populations where many common clinical events would qualify as serious adverse events in the context of a drug trial.

Combined palliative procedures for cyanotic congenital heart defects with intractable hypoplasia of pulmonary arteries

To explore the clinical experiences of combined palliative procedures for cyanotic congenital heart defects with intractable hypoplasia of pulmonary arteries. From August 2001 to September 2009, 31 patients with cyanotic congenital heart defects and intractable hypoplasia of pulmonary arteries underwent surgical procedures. Among them, 26 patients were pulmonary atresia with ventricular septal defect and the other 5 cases complicated congenital heart defects with pulmonary stenosis. Different kinds of palliative procedures were performed according to the morphology of right and left pulmonary arteries in every patient. If the pulmonary artery was well developed, Glenn procedure was performed. Modified Blalock-Taussig or Waterston shunt was performed if pulmonary arteries had hypoplasia. If the pulmonary arteries were of severe hypoplasia, Melbourne shunt was performed. Systemic-pulmonary artery shunts were performed bilaterally in 23 cases. Systemic-pulmonary shunt was performed in one side and Glenn procedure contralaterally in 8 cases. There was one early death because of cardiac arrest. The number of patients suffered from low cardiac output syndrome, perfusion lung and pulmonary infection postoperatively was 5, 3 and 2, respectively. Systemic-pulmonary shunts were reperformed after the original operation in 3 cases because of occlusion of conduits. The mean follow-up time was 25 ± 16 months (6 - 72 months). Left pulmonary index (8.1 ± 3.7 vs 14.9 ± 6.2), right pulmonary index (12.7 ± 8.1 vs 17.7 ± 7.8) and pulmonary index (20.9 ± 9.4 vs 32.6 ± 11.7) increased significantly (all P < 0.001). The pulmonary diameter increased significantly after modified Blalock-Taussig shunt (5.5 ± 1.0 vs 7.0 ± 2.0), modified Waterston shunt (5.7 ± 4.0 vs 9.2 ± 3.6) and melbourne shunt (2.2 ± 0.4 vs 7.4 ± 2.5) (all P < 0.05). Bilateral pulmonary arteries developed well compared with that of preoperative condition. Hemoglobin decreased from (194 ± 27) g/L to (174 ± 24) g/L (P < 0.05) and peripheral oxygen saturation increased from (65 ± 11)% to (84 ± 6)% (P < 0.001). During the follow-up ultimate complete repair were performed in 3 cases and one patients underwent Glenn procedure. The procedures should be considered for hypoplasia of pulmonary arteries in cyanotic congenital heart defects. Combined palliative operation is an adequate therapy.

Systemic pulmonary artery shunt using a bovine mesenteric venous graft in newborns.

A new bovine mesenteric venous graft 3 or 4 mm in diameter was used for performing systemic pulmonary artery shunts in six cyanotic newborns (aged 2 to 30 days) from March 1997 onward. Clinical and echocardiographic studies proved that all shunts were patent and functioning well after an average of 8.8 months despite no postoperative anticoagulation or antiplatelet regimen. Histological examination of two grafts explanted at the time of bidirectional cavopulmonary anastomosis showed no dense fibrotic mural infiltration, calcification, or anastomotic hyperplasia. Bovine mesenteric venous grafts can be used for the construction of systemic pulmonary artery shunts with advantages similar to that of human vein allografts, such as the facility of implantation, good short- and mid-term patency, easy takedown, and avoidance of complications presumably specific to polytetrafluoroethylene.

The Adjustable Systemic-Pulmonary Artery Shunt Provides Precise Control of Flow In Vivo

The ratio of pulmonary:systemic blood flow (Qp:Qs) remains problematic after single ventricle reconstruction. The adjustable systemic-pulmonary artery shunt (AS) was created as a solution for this problem. Prototype ASs were created using a screw-plunger mechanism as a variable resistor. A stepper motor controls plunger displacement. Six adult dogs underwent placement of a 4-mm AS in the femoral position to test its ability to control flow. Shunts were placed as arteriovenous fistulae to simulate the continuous flow of systemic-pulmonary AS. The 3.5-mm control shunts (CS) were placed on the contralateral side. The stepper motor was rotated from fully open to 3.4 mm of plunger depression for six complete cycles. Flow in the fully open AS was 687.9 +/- 28.7 cc/min* vs. 578.7 +/- 26.8 cc/min in the CS (flow +/- standard error, *p < 0.005 vs. CS). Standard deviation of flow was similar between the AS and CS, implying hysteresis in resistor function did not contribute to flow variability. Peak torque requirement to turn the resistor was 2.4 mNm. The AS offers excellent control of flow in vivo. Control of Qp:Qs may lead to improved outcomes for single ventricle reconstructions.

Surgical strategy for pulmonary atresia with intact ventricular septum: initial management and definitive surgery

Pulmonary atresia with intact ventricular septum is difficult to manage, and the surgical procedures are associated with high mortality and morbidity. The lesion is morphologically heterogeneous, with varying degrees of right ventricular and tricuspid valve hypoplasia. Aberrations of the coronary circulation are common. A single approach is impractical because the wide spectrum of right heart morphology makes a uniform surgical approach impossible. Anatomical criteria, such as the degree of tricuspid valve or right ventricular hypoplasia or whether a right ventricular infundibulum is present, have been used to assign the infants to single-ventricular or biventricular repair tracks. If the patient is considered a candidate for biventricular repair, right ventricular decompression, either alone or combined with a systemic-pulmonary artery shunt, is performed, whereas only a systemic-pulmonary artery shunt is performed in a candidate for single-ventricular repair. Several authors reported that the Z-value of the tricuspid valve diameter could be a guide to the initial procedure; however, poor interobserver reproducibility and wide normal ranges are serious limitations. Definitive operations, including biventricular repair, one-and-a-half ventricular repair, or Fontan-type operation, are performed to eliminate cyanosis. The most important problem when planning a strategy for a definitive repair is the fact that right ventricular growth and its contribution to pulmonary flow is difficult to predict before the operation. The management protocol should be determined by the precisely estimated morphology of the right ventricle and tricuspid valve, and the adequacy of the protocol should be analyzed based on surgical outcomes.