Blalock-Taussig Research Articles

Preoperative risk factors influencing inter-stage mortality after the Norwood procedure.

With improvements in early survival after the stage I palliation (S1P) Norwood procedure for hypoplastic left heart syndrome (HLHS) and its variants, inter-stage death accounts for an increasing proportion of mortality. Our aim was to identify the risk factors for inter-stage mortality. The records of 322 neonates with HLHS or a variant who underwent the Norwood procedure at our centre between 2001 and 2019 were retrospectively analysed. The diagnoses included 271 neonates with HLHS (84%) and 51 with variants (16%). Aortic atresia was observed in 138 (43%) patients, mitral atresia in 91 (28%), extracardiac anomalies in 42 (13%) and genetic disorder in 14 (4%). The median age and weight of the patients at the S1P Norwood procedure were 9 (interquartile range: 7-12) days and 3.2 (2.9-3.5) kg, respectively. The median cardiopulmonary bypass time was 137 (107-163) min. Modified Blalock-Taussig shunts were used in 159 (49%) and unvalved right ventricle-to-pulmonary artery shunts in 163 (51%) patients. The number of inter-stage deaths was as follows: between S1P and stage II palliation (S2P), 61 including 38 early (<30 days) and 23 late (>30 days) deaths, and between S2P and stage III palliation, 32 deaths. Low birth weight (<2.5 kg) (odds ratio 4.37, P = 0.020) and restrictive atrial septum (odds ratio 2.97, P = 0.013) were identified as risks for early mortality. Low birth weight [hazard ratio (HR) 0.99/g, P = 0.002] was a risk for inter-stage mortality between S1P and S2P. Extracardiac anomalies (HR 4.75, P = 0.049) and significant pre-S1P atrioventricular valve regurgitation (HR: 7.72, P = 0.016) were risks for inter-stage mortality between S2P and stage III palliation. Other anatomical variables including aortic atresia, anatomical subtypes and the diameter of the ascending aorta nor shunt type were not identified as risk factors for mortality during any inter-stage period. The risk factors for inter-stage attrition after the Norwood procedure were different between each stage. Preoperative factors, including birth weight, restrictive atrial septum and extracardiac anomalies, adversely affected the inter-stage mortality.

Valproic Acid Administration in Management of Status Epilepticus Causing Reye’s Syndrome

AbstractIntroduction Valproic acid is commonly used to treat seizures in children. Regular use of valproic acid is known to cause hepatic dysfunction, and in extremely rare cases, it is known to have caused Reye’s syndrome. There are very few reports of Reye’s syndrome caused by valproic acid use.Methods A 2-year asymptomatic girl underwent modified Blalock–Taussig shunt surgery for correction of tetralogy of Fallot. Postoperatively the girl developed status epilepticus, which did not subside with initial use of intravenous midazolam and phenytoin sodium. She eventually responded to two doses of intravenous valproic acid administered 10 minutes apart. She developed depressed sensorium and was put on mechanical ventilation. The following day’s laboratory investigations revealed raised levels of serum ammonia, serum glutamic-oxaloacetic transaminase (SGOT), and serum glutamic-pyruvic transaminase (SGPT) with normal serum bilirubin. Thus, a diagnosis of Reye’s syndrome was established. The patient succumbed to disease 2 days later.Discussion Reye’s syndrome is a rare and a fulminant illness seen typically in children following a viral illness and/or use of salicylates or other medications. There are rare reports of Reye’s syndrome following use of medications like valproic acid. This patient had a noninflammatory encephalopathy with hepatic dysfunction following two doses of valproic acid.Conclusion There are very few reports on Reye’s syndrome in the literature as it is a rare condition and diagnosis is difficult. Knowledge of the presentation of Reye’s syndrome is essential for treatment and management. When using drugs like valproic acid in children, liver enzymes and serum ammonia levels should be monitored.

Blalock-Taussig shunt versus duct stenting for congenital heart diseases with ductal-dependent pulmonary circulation: Multicenter international study (BLADE)

Ductal stenting (DS) procedure has been proposed as an alternative to aortopulmonary shunts in congenital heart disease with ductal-dependent pulmonary blood flow. Most reports comparing both techniques have limited numbers of patients and describe single-centre experience. The primary aim was to compare procedural overall survival to next-stage palliative or surgical repair. The secondary objectives were: – survival to 30 days, discharge, 1-year survival and up to the present; – early hospital morbidity; – incidence of re-interventions; – risk factors for morbidity and mortality; – predictive factors of success; – pulmonary artery growth. Infants < 1 year of age with duct- dependent pulmonary blood flow palliated, either mBTS or DS, as their first procedure were included. This is a retrospective, international multicenter study conducted in tertiary European centers with paediatric and congenital cardiology activity. A total of 644 patients were included. In total, 178 patients underwent DS procedure, and in 466 patients a mBTS was attempted. All baseline characteristics were similar between the 2 groups. DS procedure was elective in 78%. DS was approached predominantly from a femoral approach (65%). Most stents placed were mounted on 3.5- to 4-mm balloon and most cases required 1 or 2 stents (45%). DS was successful in 81%. DS failed was often related to univentricular physiology and duct morphology. A slightly increased risk of reintervention DS group was observed. Subsequent analysis (including the propensity score adjustment) is currently undertaken and would be available within the next months, to be described during the congress. There is a lack of data on large paediatric cohort comparing these techniques. Experienced shared from high-volume institutions would be a major interest to better define issues and may help to better establish the risk–benefit balance of the two therapeutic options.

Making a Case for Late Repair of Tetralogy of Fallot

The history of management of tetralogy of Fallot illustrates the arc of progress in congenital heart surgery. From Blalock and Thomas to Lillehei and Kirklin, operations transitioned from palliation alone to palliation followed by staged repair in childhood. In the 1970s Barratt-Boyes and Castaneda pioneered primary repair in infancy. Subsequently there was a gradual evolution from staged repair toward single-stage repair at a progressively younger age, a phenomenon that mirrored the course of the specialty. 1 Barron D.J. Tetralogy of Fallot: controversies in early management. World J Pediatr Congenit Heart Surg. 2013; 4: 186-191 Crossref PubMed Scopus (28) Google Scholar As experience grew, middle infancy was recommended as the optimal timing for elective repair. 1 Barron D.J. Tetralogy of Fallot: controversies in early management. World J Pediatr Congenit Heart Surg. 2013; 4: 186-191 Crossref PubMed Scopus (28) Google Scholar ,2 Van Arsdell G.S. Maharaj G.S. Tom J. et al. What is the optimal age for repair of tetralogy of Fallot?. Circulation. 2000; 102: III123-III129 PubMed Google Scholar Over a decade ago The Society of Thoracic Surgeons Database revealed that primary repair in infants under 1 year of age had become the dominant strategy in North America. 3 Al Habib H.F. Jacobs J.P. Mavroudis C. et al. Contemporary patterns of management of tetralogy of Fallot: data from The Society of Thoracic Surgeons Database. Ann Thorac Surg. 2010; 90: 813-820 Abstract Full Text Full Text PDF PubMed Scopus (170) Google Scholar Most patients underwent repair in the first year of life, with the majority during the first half of infancy. Although not significant, the lowest mortality for primary repair (0.6%) was observed in the most prevalent age category (3-6 months). Palliative shunting had decreased to around 10% and was mostly confined to neonates. More recently a large meta-analysis corroborated this shift toward repair in younger patients with a corollary decline in palliative staging; notably it also showed that increased mortality was associated with older patient age and prior palliation. 4 Romeo J.L.R. Etnel J.R.G. Takkenberg J.J.M. et al. Outcome after surgical repair of tetralogy of Fallot: a systematic review and meta-analysis. J Thorac Cardiovasc Surg. 2020; 159: 220-236 Abstract Full Text Full Text PDF Scopus (13) Google Scholar Staged Repair of Tetralogy of Fallot: A Strategy for Optimizing Clinical and Functional OutcomesThe Annals of Thoracic SurgeryVol. 113Issue 5PreviewThis study evaluated the impact of a staged surgical strategy incorporating a modified Blalock-Taussig shunt (BTS) for tetralogy of Fallot on pulmonary valve annulus growth, the rate of valve-sparing repair at the time of intracardiac repair, and long-term functional outcomes. Full-Text PDF

Intrapulmonary artery septation for unilateral absence of the pulmonary artery.

We describe a seven-month-old boy with tetralogy of Fallot and an absent left pulmonary artery. Due to the diminutive size of the left pulmonary artery, we performed a native tissue left pulmonary artery reconstruction and intrapulmonary artery septation procedure with a left modified Blalock-Taussig shunt. After confirming left pulmonary artery growth, the patient underwent tetralogy of Fallot repair, removal of septation patch, and division of the Blalock-Taussig shunt. Nine months post-surgery, we confirmed his balanced lung perfusion (R/L ratio 6:4). The intrapulmonary artery septation procedure would be suitable for both the resuscitation and reconstruction of the hypoplastic absent pulmonary artery.

Late Follow-Up of Rastelli Operation After One-Stage Repair with Right Ventricular Remodeling

We report long-term outcomes after one-stage, surgical repair, at an 11-year-old, girl with pulmonary atresia with a ventricular septal defect and anomalous origin of the left coronary artery from the right coronary artery, crossing the right ventricular outflow tract. The operation was carried out with the remodeling of the right ventricle, using a swine valved conduit prosthesis (22mm). Twenty-nine years later, the patient is in excellent clinical condition, CF I (NYHA), with normal peripheral oxygen saturation. Recent invasive and not invasive imaging show: the absence of intracardiac shunt, despite presenting prosthesis calcification and signs of mild double lesion of the prosthetic valve. The pulmonary flow is directed uniformly for both lungs. Patients undergoing the implantation of valved conduits during childhood, present mismatch, after a few years of follow-up, and are required to undergo frequent reoperations. In this patient, the indication of a Blalock-Taussig shunt, during childhood, allowed to postpone the surgery and implant a valved conduit with a larger diameter, achieving a long follow-up with a single prosthetic implant.

Palliative Balloon Pulmonary Valvotomy in Tetralogy of Fallot: Is There a Role in 2021?

The current treatment practice for Tetralogy of Fallot (TOF) is to undertake complete surgical repair between 6–9 months of age with excellent immediate and long-term results. In patients with increased cyanosis or frequent cyanotic spells, younger age of complete repair as early as 3 months is usually acceptable. Although neonatal TOF repair is reported with good immediate survival from a few centres, post-operative morbidity is significant, and the hospital stay is prolonged. Hence, in neonates and small term and preterm infants with severe cyanosis, palliative procedures such as modified Blalock-Taussig (BT) shunt, ductal stenting, right ventricular outflow tract (RVOT) stenting and balloon pulmonary valvotomy (BPV) have been reported. With the development of low-profile stents, an increasing clinician experience and more predictable outcome with both duct and RVOT stenting, these procedures have gained popularity as the preferred palliations for TOF at most centres. We reviewed the literature to analyse whether BPV for TOF palliation, a technique first reported three decades ago, still has a role in the present era of paediatric cardiac care. In this review, we have concluded that BPV has very specific indications in patients with TOF, with predominantly valvar pulmonary stenosis, and may be a preferred option over other palliative strategies in hypoxemic preterm or low-birth weight infants.

An Efficient Assisted Bidirectional Glenn Design With Lowered Superior Vena Cava Pressure for Stage-One Single Ventricle Patients.

Recently, the assisted bidirectional Glenn (ABG) procedure has been proposed as an alternative to the modified Blalock-Taussig shunt (mBTS) operation for neonates with single-ventricle physiology. Despite success in reducing heart workload and maintaining sufficient pulmonary flow, the ABG also raised the superior vena cava (SVC) pressure to a level that may not be tolerated by infants. To lower the SVC pressure, we propose a modified version of the ABG (mABG), in which a shunt with a slit-shaped nozzle exit is inserted at the junction of the right and left brachiocephalic veins. The proposed operation is compared against the ABG, the mBTS, and the bidirectional Glenn (BDG) operations using closed-loop multiscale simulations. Both normal (2.3 Wood units-m2) and high (7 Wood units-m2) pulmonary vascular resistance (PVR) values are simulated. The mABG provides the highest oxygen saturation, oxygen delivery, and pulmonary flow rate in comparison to the BDG and the ABG. At normal PVR, the SVC pressure is significantly reduced below that of the ABG and the BDG (mABG: 4; ABG: 8; BDG: 6; mBTS: 3 mmHg). However, the SVC pressure remains high at high PVR (mABG: 15; ABG: 16; BDG: 12; mBTS: 3 mmHg), motivating an optimization study to improve the ABG hemodynamics efficiency for a broader range of conditions in the future. Overall, the mABG preserves all advantages of the original ABG procedure while reducing the SVC pressure at normal PVR.

Effectiveness of antithrombotic prophylaxis in paediatric cardiosurgical patients

Aim. To evaluate the effectiveness of prevention measures for thrombotic catheter-associated events in the perioperative management of patients undergoing cardiac surgery.Methods. A total of 433 paediatric and neonatal patients were included in the study during the period from January to December 2018. All patients received antithrombotic prophylaxis via systemic heparin administration.Results. Thirty-six patients displayed signs of thrombosis during the postoperative period (8.31%): 28 patients had venous thrombosis, while 6 had the Blalock-Taussig shunt thrombosis, and 2 had arterial thrombosis. The mortality rate was higher in the group with registered thrombosis than in the group without thrombosis (p = 0.01).Conclusion. The dosage regimen for children and neonatal patients should be according to age-associated antithrombotic drug standards. It requires an integral approach for evaluating the effectiveness of preventive and therapeutic measures. Received 25 August 2020. Revised 18 December 2020. Accepted 22 December 2020. Funding: The study did not have sponsorship. Conflict of interest: Author declares no conflict of interest.

Clinical Features of Infective Modified Blalock–Taussig Shunt Obstruction

modified Blalock–Taussig shunt (mBTS）感染性閉塞は症例報告が散見される程度で，全体像は不明な点が多い．自験6例の経過から臨床像の把握と治療方針の検討を行った．基礎疾患はFallot四徴2例，完全型房室中隔欠損兼肺動脈閉鎖・純型肺動脈閉鎖・三尖弁閉鎖・総動脈幹遺残各1例であった．mBTS閉塞時に感染性閉塞と診断したのは2例のみで，残りは閉塞判明後の精査で感染性閉塞と診断した．起因菌はメチシリン耐性コアグラーゼ陰性ブドウ球菌3例，サルモネラ菌・セラチア菌・表皮ブドウ球菌各1例であった．3例でmBTS近位側吻合部に仮性瘤を形成した．新規の肺血流供給源をoriginal BTS（2例），心臓カテーテル治療によるmBTS再開通・右室流出路形成術・右室肺動脈導管サイズアップ（各1例）により確保した．右室肺動脈導管サイズアップ以外では肺血流確保が不可能な1例のみ人工物を使用した．心臓カテーテル治療でmBTSが再開通した1例以外で感染巣（人工血管グラフト，仮性瘤）を除去した．mBTS感染性閉塞では，閉塞との関連を疑う病歴の乏しい症例もあり注意を要する．mBTS近位側吻合部の仮性瘤は感染性閉塞を示唆する．（1）低酸素血症への対応，（2）新たな肺血流供給源の確立，（3）人工物を使用しない術式，（4）感染巣除去，を基本に症例ごとに治療方針を検討する必要がある．

Patients’ characteristics following reoperation after Modified Blalock-Taussig Shunt (MBTS) in Cardiac Centre National General Hospital Cipto Mangunkusumo from 2018-2020

Background: Modified Blalock-Taussig shunt (MBTS) is a common palliative procedure for congenital heart defect to connect the systemic to the pulmonary circulation via a synthetic shunt from a subclavian artery to a pulmonary artery. However, certain postoperative complications do exist, such as blockage. Early identification of modifiable risk factors is important to prompt early intervention for better outcomes.Material: This article is a descriptive narrative retrospective study. We gather data from the Cipto Mangunkusumo Hospital Cardiovascular Center medical report of 8 patients having undergone reoperation post-MBTS surgery as their first operation between January 2018 and October 2020. Data were analyzed using SPSS version 20 for Windows.Results: The patient’s age ranged from 3 months to 30 years old. Seven of them suffered from shunt occlusion complications, while the other suffered from the bleeding problem. The laboratory results showed that preoperative hemoglobin (18.9±4.1 g/dL vs. 16.90 (10.80-19.20) g/dL), hematocrit (58.8±12.40% vs. 42.9±14.30%), platelet counts (284.487±147.003 vs. 210.625±104.688) 103/uL, and oxygen saturation (86.00 (75.00-89.00) vs. 70.00±17.00) levels were higher than the pre-reoperative. The coagulation markers showed that PT value has increasing trend (1.10 (0.90-2.30) vs. 1.30±0.20) while aPTT (5.90 (2.90-6.30) vs. 2.30 (1.60-5.30)) seconds and activated clotting time (ACT) (205.00±86.00 vs. 165.00 (114.00-255.00)) showed the opposite.Conclusion: MBTS remains the first-choice bridging palliation surgery to increase the pulmonary blood flow in congenital heart defects. The cause of shunt failure remains inconclusive in this study. Other studies suggest that graft material choice, S/PA ratio, S/W ratio, operative approach, thrombus formation, and aPTT value contribute to shunt failure, thus needing a reoperation.

Staged Repair of Tetralogy of Fallot: A Strategy for Optimizing Clinical and Functional Outcomes

BackgroundThis study evaluated the impact of a staged surgical strategy incorporating a modified Blalock-Taussig shunt (BTS) for tetralogy of Fallot on pulmonary valve annulus growth, the rate of valve-sparing repair at the time of intracardiac repair, and long-term functional outcomes. MethodsThis retrospective study involved 330 patients with tetralogy of Fallot who underwent intracardiac repair between 1991 and 2019 and included 57 patients (17%) who underwent BTS. The mean follow-up period was 15.0 ± 7.3 years. We compared the data of patients who underwent BTS and patients who did not undergo BTS before intracardiac repair. ResultsThe median age before BTS was 71 days (range, 28 to 199) and the median body weight was 4.3 kg (range, 3.3 to 6.8 kg). There were no inhospital or interstage deaths after BTS. The pulmonary valve annulus Z scores of patients with BTS revealed significant growth after BTS (from −4.2 ± 1.8 to −3.0 ± 1.7, P < .001). Valve-sparing repair was eventually performed in 207 patients (63%), including 26 (46%) who underwent staged repair. The overall freedom from pulmonary regurgitation-related reintervention was 99.7%, 99.1%, and 95.8% at 1, 5, and 20 years, respectively. ConclusionsA staged surgical strategy incorporating BTS as the first palliation for symptomatic patients resulted in no mortality. Blalock-Taussig shunt may have contributed to the avoidance of primary transannular patch repair and facilitated pulmonary valve annulus growth; therefore, approximately half of the symptomatic neonates and infants were recruited for valve-sparing repair. Staged repair may have led to functionally reliable delayed transannular patch repair, thereby resulting in fewer surgical reinterventions.

Risk analysis for patients with a functionally univentricular heart after systemic-to-pulmonary shunt placement.

To investigate risk factors for mortality after systemic-to-pulmonary (SP) shunt procedures in patients with a functionally univentricular heart using the Japan Cardiovascular Surgery Database registry. Clinical data from 75 domestic institutions were collected. Overall, 812 patients with a functionally univentricular heart who underwent initial SP shunt palliation were eligible for analysis. Patients with pulmonary atresia with an intact ventricular septum and patients with a SP shunt as part of the Norwood procedure were excluded. Risk factors for 30- and 90-day mortalities were analysed using a logistic regression model. Median age and body weight at SP shunt placement were 41 days and 3.6 kg, respectively. Modified Blalock-Taussig shunt, central shunt and other types of SP shunts were applied in 689 (84.9%), 94 (11.8%) and 30 (3.7%) patients, respectively. Cardiopulmonary bypass was utilized in 410 patients (51%) for 128 min (median, 19-561). There were 411 isolated SP shunt procedures. Median hospital stay was 27 days, and 742 (91.4%) patients were discharged. The 30- and 90-day mortality rates were 3.4% and 6.0%, respectively. Placement of a central shunt was identified as a risk factor for 30-day mortality, while lower body weight, preoperative ventilator support, right atrial isomerism and coexistence of major aortopulmonary collateral arteries and an unbalanced atrioventricular septal defect were identified as risk factors for 90-day mortality. SP shunt carries a high mortality rate in patients with a functionally univentricular heart when it is performed in smaller patients with complex cardiac anomalies.

Tetralogy of Fallot: stent palliation or neonatal repair?

Surgical repair of Tetralogy of Fallot has excellent outcomes, with over 90% of patients alive at 30 years. The ideal time for surgical repair is between 3 and 11 months of age. However, the symptomatic neonate with Tetralogy of Fallot may require earlier intervention: either a palliative intervention (right ventricular outflow tract stent, ductal stent, balloon pulmonary valvuloplasty, or Blalock-Taussig shunt) followed by a surgical repair later on, or a complete surgical repair in the neonatal period. Indications for palliation include prematurity, complex anatomy, small pulmonary artery size, and comorbidities. Given that outcomes after right ventricular outflow tract stent palliation are particularly promising - there is low mortality and morbidity, and consistently increased oxygen saturations and increased pulmonary artery z-scores - it is now considered the first-line palliative option. Disadvantages of right ventricular outflow tract stenting include increased cardiopulmonary bypass time at later repair and the stent preventing pulmonary valve preservation. However, neonatal surgical repair is associated with increased short-term complications and hospital length of stay compared to staged repair. Both staged repair and primary repair appear to have similar long-term mortality and morbidity, but more evidence is needed assessing long-term outcomes for right ventricular outflow tract stent palliation patients.

Patent Ductus Arteriosus Stenting for All Ductal-Dependent Cyanotic Infants: Waning Use of Blalock-Taussig Shunts.

[Figure: see text].

Infants with pulmonary atresia intact ventricular septum who require balloon atrial septostomy have significantly higher 18-month mortality.

Many newborns with pulmonary atresia/intact ventricular septum require intervention to establish pulmonary flow and sufficient cardiac output. The resulting haemodynamic changes are not well characterised and may have unintended consequences. This is a 30-year (1988-2018) retrospective study of patients with pulmonary atresia intact ventricular septum. Eighty-nine patients were included, and median follow-up was 8 years. Fifty-five per cent had coronary sinusoids and 27% had right ventricular-dependent coronary circulation. Most patients were managed with surgical aortopulmonary or modified Blalock-Taussig shunt (73%), and 12 patients underwent balloon atrial septostomy before surgical intervention. The remaining patients (27%) underwent only transcatheter interventions; 7 required an atrial septostomy and 17 required ductal stentings. All-cause mortality was 10%, most deaths (89%) occurred before 18 months of age. Of these early deaths, 87% required a balloon atrial septostomy and 85% had right ventricular-dependent coronary sinusoids. Eighteen-month mortality was significantly higher for patients who required a balloon atrial septostomy compared to those who did not (36% versus 1.4% p < 0.0001). Patients with pulmonary atresia/intact ventricular septum who require balloon atrial septostomy in the newborn period have significantly higher 18-month mortality. Quantifying the mortality difference may help guide prognostication and expectation setting. Infants who had septostomy and a surgical shunt in the newborn period fared better than those who only underwent septostomy (even when accompanied by ductal stenting). For infants with right ventricular-dependent circulation, atrial septostomy should only be performed on an urgent or emergent basis and these patients should be considered for early surgical intervention and neonatal transplant.

Safety of Sildenafil Use in Patients with BT Shunt Dependent Congenital Heart Disease

Safety of Sildenafil Use in Patients with BT Shunt Dependent Congenital Heart Disease

Multiscale modeling of a modified Blalock-Taussig surgery in a patient-specific tetralogy of Fallot.

Tetralogy of Fallot (TOF) is a congenital heart anomaly that causes a drastic reduction in the oxygen level. In this study, we coupled a lumped-parameter model with a patient-specific three-dimensional (3D) model which included a modified Blalock-Taussig (MBT) shunt. By forming a closed loop, we investigated the effects of certain parameters on the flow rates and the pressures at different locations of the developed network. A local sensitivity analysis on an initial zero-dimensional (0D) closed-loop model was conducted. The 0D lumped parameter (LP) model was then refined based on the results of the multiscale 0D-3D model and the local sensitivity analysis was repeated for the refined 0D model. It was shown that the maximum pressure of the pulmonary bed had the highest sensitivity of 94% to the diameter of MBT shunt. We observed that the existence of the flow in the shunt during the diastole caused an elevated wall shear stress (WSS) in the pulmonary artery. In this work, we calculated the flow velocity and pressure field in a 3D patient-specific aorta with an MBT shunt, and then we used the results to increase the accuracy of our LP model to simulate numerous 0D simulations in a significantly shorter time, which is potentially applicable for medical decision-making.

Anterograde blood flow associated with modified Blalock–Taussig shunt does not modify pulmonary artery growth compared with modified Blalock–Taussig shunt alone

The main difference between extreme tetralogy of Fallot (TOF) and pulmonary atresia with ventricle septal defect (PA/VSD) is anterograde pulmonary blood flow (APBF). It is speculated that the association of modified Blalock-Taussig shunt (mBTS) with APBF favours shunt thrombosis, but promotes better pulmonary artery growth. To compare pulmonary artery growth after mBTS between TOF and PA/VSD. From 1995 to 2018, 77 mBTS procedures were performed in infants (aged<1 year): 45 for TOF; 32 for PA/VSD. Using a 1/1 propensity score-matched analysis, 38 patients were included (19 per group). Delta Nakata was defined as the difference in the Nakata index before biventricular repair and before mBTS. After matching, the preoperative Nakata index was similar in the two groups (TOF 101±34 vs. PA/VSD 106±35 mm2/m2; P=0.75). Age and weight were similar (TOF 24±20 days, 3.3±0.6kg vs. PA/VSD 24±33 days, 3.3±0.9kg; P=0.84 and P=0.77, respectively). There was no difference in rates of in-hospital mortality (TOF 0% vs. PA/VSD 10%; P=0.13) or mBTS thrombosis (TOF 15% vs. PA/VSD 10%; P=0.63). The left and right pulmonary artery diameters at time of biventricular repair were similar (TOF 7.5±2.2 and 6.7±2.1 vs. PA/VSD 8±2.7 and 7.1±2.5mm; P=0.43 and P=0.78, respectively), as were delta Nakata (TOF 112±102 vs. PA/VSD 107±66 mm2/m2; P=0.89), median age for biventricular repair (P=0.83) and reintervention rates (TOF 10% vs. PA/VSD 15%; P=0.67). We found no difference in pulmonary artery growth between APBF with mBTS versus mBTS alone. Thus, we could not show an increase in mBTS thrombosis with APBF.

Predictors of death after receiving a modified Blalock-Taussig shunt in cyanotic heart children: A competing risk analysis.

ObjectiveTo determine risk factors affecting time-to-death ≤90 and >90 days in children who underwent a modified Blalock-Taussig shunt (MBTS).MethodsData from a retrospective cohort study were obtained from children aged 0–3 years who experienced MBTS between 2005 and 2016. Time-to-death (prior to Glenn/repair), time-to-alive up until December 2017 without repair, and time-to-progression to Glenn/repair following MBTS were presented using competing risks survival analysis. Demographic, surgical and anesthesia-related factors were recorded. Time-to-death ≤90 days and >90 days was analyzed using multivariate time-dependent Cox regression models to identify independent predictors and presented by adjusted hazard ratios (HR) and 95% confidence intervals (CI).ResultsOf 380 children, 119 died, 122 survived and 139 progressed to Glenn/repair. Time-to-death probability (95% CI) within 90 days was 0.18 (0.14–0.22). Predictors of time-to-death ≤90 days (n = 63) were low weight (<3 kg) (HR 7.6, 95% CI:2.8–20.4), preoperative ventilator support (HR 2.7, 95% CI:1.3–5.6), postoperative shunt thrombosis (HR 5.0, 95% CI:2.4–10.4), bleeding (HR 4.5, 95% CI:2.1–9.4) and renal failure (HR 4.1, 95% CI:1.5–10.9). Predictors of time-to-death >90 days (n = 56) were children diagnosed with pulmonary atresia with ventricular septal defect and single ventricle (compared to tetralogy of fallot) (HR 3.2, 95% CI:1.2–7.7 and HR 3.1, 95% CI:1.3–7.6, respectively), shunt size/weight ratio >1.1 vs <0.65 (HR 6.8, 95% CI:1.4–32.6) and longer duration of mechanical ventilator (HR 1.002, 95% CI:1.001–1.004). Shunt size/weight ratio ≥1.0 (vs <1.0) and ≥0.65 (vs <0.65) were predictors for overall time-to-death in neonates and toddlers, respectively (HR 13.1, 95% CI:2.8–61.4 and HR 7.8, 95% CI:1.7–34.8, respectively).ConclusionsPerioperative factors were associated with time-to-death ≤90 days, whereas particular cardiac defect, larger shunt size/weight ratio, and longer mechanical ventilation were associated with time-to-death >90 days after receiving MBTS. Larger shunt size/weight ratio should be reevaluated within 90 days to minimize the risk of shunt over flow.