Glenn Procedure Research Articles

Glenn surgery: a safe procedure in the path of univentricular correction.

This study describes 35 years of experience in a tertiary care level hospital that treats cardiac patients with univentricular heart physiology who underwent Glenn surgery. The study consisted of a retrospective analysis of patients who underwent Glenn surgery, including variables related to pre-operative, intra-operative, and post-operative morbidity and mortality. From 1980 to 2015, 204 Glenn surgeries were performed. The most common heart disease was tricuspid atresia IB (19.2%). In 48.1% of the cases, the procedure was performed with antegrade flow. A bilateral Glenn procedure was performed in 12.5% of the cases and 10.3% were carried out without using a cardiopulmonary bypass pump. Reported complications included infections, bleeding, arrhythmias, chylothorax, neurological alterations, and pleural effusion. The mortality rate was 2.9%. Glenn surgery is a palliative surgery with good results. It significantly improves patient quality of life over a long period until a total cavopulmonary shunt is performed. The complications observed are few, and the mortality rate is low. Therefore, it is a safe surgery that should be used for univentricular congenital heart disease.

Pulmonary artery banding in patients with functional single ventricle associated with pulmonary hypertension

ABSTRACT Background: To assess the impact of our surgical strategy for the treatment of patients with functional single ventricle and pulmonary hypertension, especially in patients>24 months old. Methods We retrospectively analyzed the clinical data of 97 patients with functional single ventricle and pulmonary hypertension undergoing pulmonary artery banding (PAB) in our hospital between April 2010 and December 2018. The surgical results, transition to Glenn operation and subsequent transition to Fontan operation were analyzed. Results: The 97 patients underwent PAB included 34 patients>24 months old, hospital mortality was 2.1% (2/97). 62 patients underwent the second-stage Glenn operation, and 21 patients underwent third-stage Fontan operation. On competing risk analysis, at 80 months after PAB, 81% had undergone the Glenn operation, and 13% were awaiting the Glenn operation. At 35 months after the Glenn operation, 2% of patients had died, 63% had undergone the Fontan operation, and 36% were awaiting the Fontan operation. Conclusion: PAB is an acceptable strategy for patients with functional single ventricle associated with pulmonary hypertension. Outcomes and results of subsequent Glenn and Fontan procedures are generally good included patients>24 months. Accompanied with unbalanced atrioventricular septal defect for lower ratio of transition to Glenn and Fontan operation.

Determination of the Cause for Persistent Hypoxemia by Transesophageal Echocardiography After a Fontan Completion

•Pulmonary arteriovenous malformations can occur following Glenn procedures and can remain undetected at the time of Fontan completion. They may cause persistent hypoxemia. Agitated saline injection during transthoracic/transesophageal echocardiography into the venous system with immediate appearance of the agitated saline in the left heart within 3 cardiac cycles may be an easy, minimally invasive bedside diagnostic test for the condition.

Comparison of Quantitative Versus Qualitative Assessment of Single Right Ventricular Function for the Prediction of Midterm Outcomes

Multiple studies have shown that quantitative evaluation of right ventricular (RV) systolic function in children with hypoplastic left heart syndrome (HLHS) is associated with outcomes. However, the most widely used method is qualitative, or subjective echocardiographic evaluation. Tricuspid annular displacement (TMAD) is a quantitative method and has been shown to be associated with transplant/death in a cohort of pediatric patients with HLHS. In this study, the same echocardiograms used in the quantitative TMAD study were qualitatively evaluated to see if the assessment correlated with midterm outcomes. We hypothesized that TMAD measures would outperform qualitative measurements. A previously published retrospective study of patients with systemic right ventricle demonstrated that TMAD measurements of function prior to the Glenn procedure were associated with midterm mortality/transplant (mean TMAD 12.4% for survivors and 10.0% for non-survivors/transplant, p = 0.03). Echocardiographic images used in that study were re-evaluated using qualitative assessment of function. A score between severely depressed (0) and supra-normal (7) was assigned independently by three cardiologists. A chart review included short-term clinical outcome measures in addition to midterm mortality/transplant. Spearman correlations and logistic regression were used to estimate the associations between function scores and clinical outcomes. Function scores were measured with acceptable inter- and intra-rater reliabilities in 47 patients who had echocardiograms used in the prior analysis before their bidirectional Glenn. The mean functional score was 5.3 ± 1.32 in survivors and 5.0 ± 1.02 in non-survivors/transplant. Subjective echocardiographic scores of function were not predictive of mortality (p = 0.23). Scores were correlated with length of cardiac intensive care unit stay (Spearman's rho = - 0.31, p = 0.04), but not post-Glenn total length of hospital stay (p = 0.4). A sub-analysis was performed for each individual operator. Only one of three operators produced scores with a significant association with mortality/transplant (p = 0.01, p = 0.25, p = 0.22, respectively). Averaged subjective measurement of function by three pediatric cardiologists in children with single right ventricle prior to the Glenn procedure was not associated with midterm outcomes. Previous work based on the same echocardiograms showed that quantitative analysis was associated with midterm outcomes. This suggests quantitative analysis may be more useful in prognostication. Future studies could confirm these results and identify which quantitative methods are most helpful.

The Glenn procedure: Clinical outcomes in patients with congenital heart disease in pakistan.

Objectives:Congenital heart defects (CHDs) affect more than 40,000 children annually in Pakistan. Approximately 80% of patients require at least one surgical intervention to achieve a complete or palliative cardiac repair. The Glenn shunt, a palliative procedure is established between superior vena cava (SVC) and the right pulmonary artery to provide an anastomosis offering minimal risk to patients with univentricular heart disease. The aim of this study was to assess the clinical outcomes of the Glenn shunt procedure in patients with complex congenital heart diseases in a developing country like Pakistan.Materials and Methods:A retrospective chart review was conducted on patients who underwent a bidirectional Glenn shunt procedure from July 2006 to June 2017. Data were collected on a structured questionnaire and analyses performed on SPSS version 22. Frequencies and percentages were computed for categorical variables while mean and standard deviation for continuous variables where appropriate.Results:A total of 79 patients underwent the Glenn shunt procedures. The median age was 1.9 years and 54.5% were male. Tricuspid atresia was the primary diagnosis in 30.4% of the patients. Common morbidities included arrhythmias (6.3%), pleural effusion (8.9%), wound infection (3.8%), pneumonia (2.5%), and seizures (3.8%); reopening was required in 2.5% of the patients and 8.8% were readmitted within 30 days of index operation. There were three (3.8%) deaths in total.Conclusions:Bidirectional Glenn shunt procedure can be performed safely in patients with ideal characteristics as the first stage palliation and has favorable results with acceptable rate of complications.

Surgical Correction of Scoliosis in Children with Severe Congenital Heart Disease and Palliated Single Ventricle Physiology.

Case series. In this study we focus on this group, and describe the largest cohort to date of single ventricle patients undergoing surgical correction of scoliosis at a single institution. Outcomes of spinal surgery for patients with congenital heart disease (CHD) have evolved and most affected patients have uncomplicated procedures. The risk of perioperative complications remains highest in patients with single ventricle ("Fontan") physiology. We reviewed patients with single ventricle CHD and operative scoliosis repair over a 25-year span. Patients who had undergone a Fontan, bidirectional Glenn, and/or Kawashima procedure before operative scoliosis repair were included. Patients were excluded if they lacked preoperative cardiac care and/or sufficient medical history at our institution. Twenty-three patients were included. The average age at surgery was 13.6 years (range, 5-23). Seventy percent of the cohort was female (16/23). The majority of patients underwent a Fontan before scoliosis surgery (20/23, 87%). Patients without intraoperative tranexamic acid (TXA) had a 67% complication rate (8/12) versus 36% (4/11) in those with intraoperative TXA (P = 0.29). There was a significant difference in estimated blood loss by weight (cc/kg) between non-TXA and TXA patients (P = 0.016). Twelve patients experienced complications (52%), all of which occurred postoperatively. There were no deaths, cerebrovascular events, adverse perioperative cardiac or hemodynamic complications, or wound infections. Using the Clavien-Dindo-Sink classification for postoperative complications, four patients had serious adverse events, including one permanent neurologic deficit. Spinal surgery for scoliosis has been performed in selected patients with single ventricle physiology at a single institution without mortality for 25 years. Operative blood loss may be reduced by routine use of TXA. Complications occur most commonly in the postoperative period, and can include pleural effusion.Level of Evidence: 4.

Deep Sedation for Patients with Single Ventricle Physiology

Background: 
 Advancements in the palliative surgery of patients with single ventricle physiology have led to an increase in lifespan, necessitating the study of safe deep sedation protocols for painful procedures. This study aims to describe the practice of deep sedation by intensivists outside the operating from for children with single ventricle physiology. 
 
 Methods: 
 A retrospective chart review was conducted on consecutive patients with single ventricle physiology who received procedural deep sedation performed by intensivists between January 2013 and July 2020. Sedative and analgesic medications used were not protocolized and were up to the discretion of the physician performing the sedation. 
 
 Results: 
 Thirty-three sedations were performed on 27 unique patients. The median age was 3.7 years (25th%, 75th%: 2.1, 15.6). The majority of procedures, 88% (29/33), were done on children with Fontan physiology. The remaining 12% (4/33) were status-post Glenn or hemi-Fontan procedure. The underlying primary cardiac defect was hypoplastic left heart in 52% (17/33) of procedures. 
 
 There were 24 chest tube placements and 9 cardioversion procedures; there were no procedural complications. 
 
 Ketamine alone [median dose 1.52 mg/kg (range 0.79-3.70)], ketamine [median dose 0.98 mg/kg (range 0.13-2.12)] with propofol [median dose 2.27 mg/kg (range 0.66-3.77)], and ketamine [median dose 1.50 mg/kg (range 0.42-3.02)] with morphine [median dose 0.06 mg/kg (range 0.03-0.20)] were the most common sedation protocols used. 
 
 There were minor complications during four procedures. One patient with transient hypotension, two had desaturation, and the fourth had desaturation and apnea. The patients with desaturation received nasal cannula oxygen delivery. The patient with apnea had bag mask valve ventilation. No intervention was reported for hypotension. 
 
 Conclusions: 
 Procedural deep sedation can be safely and effectively administered to single ventricle patients by intensivist led sedation teams.

Abstract 14882: Outcomes of Heart Failure in Hypoplastic Left Heart Syndrome and the Impact of Recovery

Introduction: Survival for children with hypoplastic left heart syndrome (HLHS) and right ventricular (RV) dysfunction (dysfxn) remain poor. We describe outcomes of HLHS patients with RV dysfxn and the long-term impact of interval normalization. Methods: The SickKids Heart Failure (HF) Database is a retrospective cohort of HF patients from 2001 to 2017. We included patients with HLHS and at least mild RV dysfxn on echocardiogram lasting >30 days, or death or transplant within 30 days of onset of dysfxn. We defined normalization as normal RV function (fxn) lasting > 30 days after dysfxn onset. The primary endpoint was death or transplant. Descriptive statistics and time to event analysis were used. Results: We identified 99 patients with a median (IQR) age at onset of dysfxn of 2.6 (1 - 5.3) months. Of these, 51 (52%) had normalization of RV fxn for a median (IQR) duration of 3.5 (0.8 - 9.1) years and 28 (55%) had multiple periods of normal fxn. Of those who normalized, 4 (8%) normalized within a few months post Glenn procedure and 6 (13%) had normal fxn at last follow up. Patients with and without normalization had similar frequency of severe dysfxn (41 vs 52%, p=0.6). Normalization of RV fxn correlated with improved transplant free survival (78 % vs. 14 %, p<0.001, Figure 1C) independent of surgical stage (p=0.03, figure 1D). Table 1 shows risk factors independently associated with transplant-free survival, including angiotensin converting enzyme inhibition. Conclusions: HLHS patients with RV dysfxn have poor transplant-free survival, especially those at interstage, but outcomes improve in those with persistent normalization of fxn. Factors predicting normalization need further study

Individual variation in unfractionated heparin dosing after pediatric cardiac surgery

We aimed to identify attributing factors to the interindividual variabilities of the infusion rates in unfractionated heparin therapy. We included patients who required unfractionated heparin therapy to achieve the target APTT after cardiac surgery between May 2014 and February 2018. Fifty-nine patients were included, of whom 8 underwent Blalock-Taussig shunt; 27, Glenn procedure; 19, Fontan procedure; 3, mechanical valve replacement; and 2, Rastelli procedure. Previously reported variables that influenced the response to unfractionated heparin treatment were initially compared, which included age; weight; sex; type of surgery; platelet count; fibrinogen, antithrombin III, total protein, albumin, alanine transaminase, and creatinine levels; and use of fresh frozen plasma. The type of surgical procedure was found to be significantly associated with the differences in heparin infusion rate (P = 0.00073). Subsequently, the variance explained by these factors was estimated through a selection based on the minimum Akaike information criterion value; models constructed by various combinations of the surgery types were compared. The model including the Blalock-Taussig shunt, Glenn procedure, and mechanical valve replacement showed the highest summed variance explained (29.1%). More than 70% of the interindividual variability in initial heparin maintenance dosing was unexplained.

Trisomy 21 Patients Undergoing Cavopulmonary Connections Need Improved Preoperative and Postoperative Care

Patients with trisomy 21 (T21) often have elevated pulmonary vascular resistance, which may result in a suboptimal cavopulmonary connection (CPC) after a Glenn or Fontan operation. The purpose of this study was to assess, in a nationwide, multiinstitution cohort of patients with CPC, the impact of T21 on patient morbidity, mortality, and resource use. A total of 23,271 pediatric patients with CPC (2004 to 2019) at 50 US hospitals were evaluated using the Pediatric Health Information System database. Univariable and multivariable regression analyses were used to assess risk-adjusted associations between Down syndrome and other risk factors and postoperative measures of morbidity, mortality, lengths of stay, and cost of hospitalization. The overall prevalence of T21 among patients who had undergone Glenn and Fontan procedures was 1.5% (199 of 13,268) and 0.8% (78 of 1003), respectively. Among both CPC cohorts, T21 status significantly increased unadjusted mortality, hospital lengths of stay, and total costs of hospitalization compared with the non-T21 CPC cohort (all P < .001). Patients with T21 also had a higher incidence of prolonged mechanical ventilation compared with patients without T21 in both Glenn and Fontan groups (P < .001). Multivariable regression analysis further estimated that patients with T21 are associated with a 5.5-fold increase in mortality (P < .001) compared with patients without T21. Finally, patients with T21 had increased long-term mortality compared with their peers. T21 significantly increases risk-adjusted morbidity, inpatient mortality, long-term mortality, and resource use after cavopulmonary connections. Further investigation is needed to clarify modifiable patient-level and center-specific risk factors to improve outcomes for patients with T21.

Systolic Color Doppler Flow Into The Aorta Through The Left Main Coronary Artery: What Is The Diagnosis?

A 5-YEAR-OLD boy (weight, 17.4 kg; height, 120 cm; body surface area, 1.02m2) with pulmonary atresia, intact ventricular septum, bipartite hypoplastic right ventricle, and tricuspid valve hypoplasia presented to the author's institution for pre-Fontan evaluation. The child had under gone a bidirectional Glenn procedure at one year of age. The electrocardiogram showed a sinus rhythm, left-axis deviation, and “ST” depression in V1-V3 leads. The origin of the left main coronary artery was dilated in a parasternal short-axis view of the aorta by transthoracic echocardiography, as well as in midesophageal aortic short-axis view by transesophageal echocardiography (Fig 1, A and B).

Right ventricular outflow tract stenting during neonatal and infancy periods: A multi-center, retrospective study.

The aim of this study was to evaluate the outcomes of right ventricular outflow tract stenting for palliation during the newborn and infancy periods. Between January 2013 and January 2018, a total of 38 patients (20 males, 18 females; median age 51 days; range, 3 days to 9 months) who underwent transcatheter right ventricular outflow tract stenting in three centers were retrospectively analyzed. Demographic characteristics, cardiac pathologies, angiographic procedural, and clinical follow-up data of the patients were recorded. The diagnoses of the cases were tetralogy of Fallot (n=27), double outlet right ventricle (n=8), complex congenital heart disease (n=2), and Ebstein"s anomaly (n=1). The median weight at the time of stent implantation was 3.5 (range, 2 to 10) kg. Five cases had genetic abnormalities. The median pre-procedural oxygen saturation was 63% (range, 44 to 80%), and the median procedural time was 60 (range, 25 to 120) min. Acute procedural success ratio was 87%. Reintervention was needed in seven of patients due to stent narrowing during follow-up. During follow-up period, seven cases died. Total correction surgery was performed in 26 patients without any mortality. While a transannular patch was used in 22 patients, valve protective surgery was implemented in two patients, and the bidirectional Glenn procedure was performed in two patients. Based on our study results, right ventricular outflow tract stenting is a form of palliation which should be considered particularly in cases in whom total correction surgery is unable to be performed due to morbidity.

The Nutritional Status of Pediatric Patients with Single Ventricle Undergoing a Bidirectional Glenn Procedure.

Single ventricle (SV) physiology is associated with growth retardation in children. The nutritional status of pediatric patients with SV undergoing a bidirectional Glenn (BDG) procedure vitally affects the feasibility of the next operation stages. To explore the nutritional status and to identify specific anthropometric parameters relevant to short-term surgical outcomes in children with SV after the BDG procedure, this study included 151 patients who underwent the BDG procedure. Anthropometric assessments and Infant and Child Feeding Index (ICFI) scores were used to evaluate nutritional status. There was a significant statistical correlation between ICFI and malnutrition in both the height-for-age Z-score (HAZ) and weight-for-age Z-score (WAZ) groups (P < 0.05). The clinical data, including ventilation time, nosocomial infection presence, pressure injury presence, peritoneal dialysis status, and total intensive care unit days, after BDG surgery were significantly different among the HAZ groups (P < 0.05), while nosocomial infection was different among the WAZ groups (P < 0.05). Children after BDG procedure had a high incidence of malnutrition, in addition to disease factors, the type and frequency of dietary intake were also important factors leading to worse clinical outcomes during hospitalization. Therefore, it is vital to maintain an optimal nutritional status in infants with SV who are undergoing a series of surgical procedures.

Impact of prior diaphragm plication on subsequent stages of single ventricle palliation

BackgroundPhrenic nerve injury is a known cause of morbidity after single ventricle palliation. Previous studies have shown that hemidiaphragm plication improves short-term outcomes. The effect of plication on the outcomes of subsequent stages of single ventricle palliation is unknown. MethodsFrom 1997 to 2015, 1146 patients underwent surgical management of single ventricle physiology at our institution. We reviewed the records of 30 patients who had undergone diaphragm plication for phrenic nerve injury before Fontan completion. Each patient was compared with 2 propensity-matched controls identified from patients who underwent the Glenn or Fontan procedure during the same period without diaphragm plication. Propensity matching was achieved for each test subject using the nearest neighbor algorithm. Data are presented as the median and quartiles or numbers and percentages. ResultsThe cohort included 18 boys (60%). Of the 30 patients, 19 (63%) had undergone plication after first-stage palliation. Of these, 13 have undergone completion Fontan, 5 were awaiting Fontan at the last follow-up, and 1 had died. An additional 11 patients had undergone plication after Glenn and proceeded to Fontan completion. Thus, 24 patients with diaphragm plication have undergone Fontan completion. No difference was found in pulmonary pressure or resistance between the plicated patients and their propensity-matched controls. Both groups had comparable chest tube output and hospital lengths of stay. Equal proportions of patients in both groups required pulmonary vasodilator therapy and/or supplemental oxygen at hospital discharge. ConclusionsPrior diaphragm plication does not adversely affect Fontan completion in children with single ventricle physiology. The hospital course during subsequent stages of palliation for plicated patients was no different than that of matched controls.

The Da Silva cone operation after the Starnes procedure for Ebstein's anomaly: New surgical strategy and initial results.

The Da Silva cone operation after the Starnes procedure for Ebstein's anomaly: New surgical strategy and initial results.

Three-dimensional imaging of pulmonary arterial vasa vasorum using optical coherence tomography in patients after bidirectional Glenn and Fontan procedures.

We evaluated pulmonary arterial (PA) vasa vasorum (VV) in Fontan candidate patients with a novel three-dimensional (3D) imaging technique using optical coherence tomography (OCT). This prospective study assessed the development of adventitial VV in the distal PA of 10 patients with bidirectional Glenn circulation (BDG group, 1.6 ± 0.3 years) and Fontan circulation (Fontan group, 3.3 ± 0.3 years), and in 20 children with normal PA haemodynamics and morphology (Control group, 1.5 ± 0.3 years). We assessed the PA VV with two-dimensional (2D) cross-sectional, multi-planar reconstruction (MPR), and volume rendering (VR) imaging. VV development was evaluated by the VV area/volume ratio, defined as the VV area/volume divided by the adventitial area/volume. Compared to the control group, the observed VV number and diameter on 3D images of MPR and VR were significantly higher, and curved and torturous-shaped VV were more frequently observed in the BDG and Fontan groups (P < 0.001, all). The median VV volume ratio was significantly greater in the BDG than in the control group (3.38% vs. 0.61%; P < 0.001). Although the VV volume ratio decreased significantly after the Fontan procedure (2.64%, P = 0.005 vs. BDG), the ratio remained higher than in the control group (P < 0.001 vs. control). 3D OCT imaging is a novel method that can be used to evaluate adventitial PA VV and may provide pathophysiological insight into the role of the PA VV in these patients.

Bidirectional Glenn Procedure in Patients Less Than 3 Months of Age: A 14-Year Experience

Contradictory data exist regarding timing of stage 2 palliation (S2P). Prolonged interstage hospitalizations and home surveillance programs have contributed to a more rapid progression to S2P. Our goal is to describe the S2P population and explore the relationships of clinical outcomes and S2P timing at our institution over the last 14 years. S2P procedures from 2004 to 2018 at a single institution were included in a retrospective analysis. The analysis was stratified by S2P timing and clinical variables. The primary outcome was Fontan completion, and secondary outcomes included mortality and orthotopic heart transplantation rate, as well as perioperative clinical variables. A total of 114 patients who underwent S2P were included. The median age and weight at S2P were 100 days (interquartile range [IQR], 87-119) and 5.1 (IQR, 4.6-5.5) kg, respectively. The median age in the early group was 79 (IQR, 73-87) days and in the nonearly group was 107 (IQR, 100-124) days. Ninety percent of cavopulmonary anastomoses were augmented with an ePTFE (expanded polytetrafluoroethylene) patch. The overall Fontan completion rate was 76%, without differences in Kaplan-Meier estimates. There were no operative mortalities and no differences in late mortality rate (P= .30). The interstage period continues to be high risk for those undergoing single-ventricle palliation. In our experience, S2P performed at less than 90 days seems to be a viable and safe procedure when indicated, resulting in comparable Fontan completion rates.

Neonatal Pulmonary Atresia With Intact Ventricular Septum—8-Year Surgical Experience at One Center

BackgroundSurgical treatment of pulmonary atresia with intact ventricular septum (PA/IVS) in neonates is challenging because of the broad variations of right ventricular (RV) malformations. In this retrospective study, we summarized our 8-y experience in surgical management for neonatal PA/IVS patients. MethodsThirty-four neonates with PA/IVS between July 1, 2006 and June 30, 2014, were reviewed. Patients were categorized into three groups: mild, moderate, and severe RV hypoplasia according to RV morphology and development. Patients were on regular follow-up for at least 5 y. Overall survival, complications, reinterventions, risk factors for mortality, and health status were evaluated. Results21 patients (61.8%) were treated with biventricular repair, eight patients (23.5%) with Fontan procedure, and one patient (2.9%) with bidirectional Glenn procedure. There were four postprocedural mortalities and one late death. The 5-y survival rates after final surgical repair for mild, moderate, and severe RV hypoplasia groups were 100%, 100%, and 88.9%, respectively. The reintervention rates were 0% (0/4), 21.4% (3/14), and 55.6% (5/9) for the subgroups, respectively. At the latest follow-up, most patients had a status characterized as New York Heart Association class I (88.9%, 24/27). ConclusionsSurgical management for PA/IVS in neonates should be individualized. Favorable early and long-term outcomes can be achieved in neonatal PA/IVS patients by individualized surgical strategies, regardless of the degree of RV hypoplasia. In spite of potential RV catch-up development, the degree of RV hypoplasia is a factor of paramount importance to assess PA/IVS in neonates.

Hemodynamic Effects of Additional Pulmonary Blood Flow on Glenn and Fontan Circulation.

Additional pulmonary blood flow (APBF) can provide better pulsating blood flow and systemic arterial oxygen saturation, while low blood pulsation and low oxygen saturation are defects of the Fontan and Glenn procedure. Studying the hemodynamic effect of APBF is beneficial for clinical decisions. This study aimed to explore the effect on particle washout, as well as the differences among the sensitivities of both different hemodynamic parameters and different procedures to APBF. The patient-specific clinical datasets of a patient who underwent bilateral bidirectional Glenn (BBDG) with APBF were enrolled in this study, and using these datasets, Glenn- and Fontan-type artery models were reconstructed. A series of parameters, including the total caval flow pulsatility index (TCPI), indexed energy loss (iPL), wall shear stress (WSS), systemic arterial oxygen saturation (Satart), particle washout time (WOT), pressure in the rightsuperior vena cava (PRSVC), pulmonary flow distribution (PFD) and hepatic flow distribution (HFD), were computed from computational fluid dynamic (CFD) simulation to evaluate the hemodynamic effect of APBF. The result showed that APBF led to better iPL and Satart but worse PRSVC and heart load accompanied by a great impact on HFD, making hepatic flow easier to perfuse the side without MPA and APBF. The increase in the APBF rate also effectively results in larger flow pulsation, region velocity, and wall shear stress and lower WOT, and this effect may be more effective for patients with persistent left superior vena cava (PLSVC). However, APBF might have little effect on PFD. Furthermore, APBF might affect WOT, iPL and HFD more significantly than PRSVC and has a greater improvement effect in patients with poorer iPL and WOT. Moderate APBF is not only a measure to promote pulmonary artery growth and systemic arterial oxygen saturation but also an effective method against endothelial dysfunction and thrombosis. However, moderate APBF is patient-specific and should be determined based on hemodynamic preference that leads to desired patient outcomes, and care should be taken to prevent PRSVC and heart load from being too high as well as an imbalance in HFD.

The effect of a valved small conduit on systemic ventricle–pulmonary artery shunt in the Norwood-type palliation

The aim of this study was to clarify the impact of valved systemic ventricle-pulmonary artery (SV-PA) shunt on outcomes after stage-1 Norwood-type palliation (NP) compared with the modified Blalock-Taussig shunt. Consecutive patients who underwent NP between 2003 and 2019 were enrolled. SV-PA shunts using the expanded polytetrafluoroethylene valved conduit were implanted in 18 patients (valved SV-PA group), and another 18 patients underwent modified Blalock-Taussig shunt during NP (modified Blalock-Taussig shunt group). All valved conduits were made in our institution in advance. No differences in baseline characteristics were found between the groups, except for shunt size. During a median 2.9 (interquartile range 0.4-6.4, maximum 14.2) years of follow-up, 8 (22.2%) patients died across both groups. There were no statistically significant differences in early mortality (5.5% vs 11.1%, P = 0.55) and overall survival rates at 5 years (80.8% vs 71.4%, P = 0.48) in the valved SV-PA and modified Blalock-Taussig shunt groups. No statistically significant difference was observed in the frequency of interventions between the groups (31% vs 33%, P = 1.0). At the time of the bidirectional Glenn procedure, the systemic ventricular end-diastolic volume index was significantly lower (84 ± 24 vs 106 ± 31 ml/m2, P = 0.05) and the ejection fraction was significantly greater (62 ± 8% vs 55 ± 9%, P = 0.03) in the valved SV-PA group. There was no statistically significant difference in the pulmonary artery index (228 ± 85 vs 226 ± 60 mm2/m2, P = 0.92). A valved SV-PA shunt using an expanded polytetrafluoroethylene valved conduit was associated with preserved ventricular function after NP and did not impair pulmonary artery growth by controlling pulmonary regurgitation.