Additional Pulmonary Blood Flow Research Articles

Utility of Balloon Occlusion Testing in Determining Fontan Suitability Among Patients with Elevated Pulmonary Artery Pressure and Additional Antegrade Pulmonary Blood Flow.

In individuals with a single ventricle undergoing evaluation before Fontan surgery, the presence of excessive pulmonary blood flow can contribute to increased pulmonary artery pressure, notably in those who had a Glenn procedure with antegrade pulmonary flow. 28 patients who had previously undergone Glenn anastomosis with antegrade pulmonary blood flow (APBF) and with elevated mean pulmonary artery (mPAP) pressure > 15mmHg in diagnostic catheter angiography were included in the study. After addressing other anatomical factors that could affect pulmonary artery pressure, APBF was occluded with semi-compliant, Wedge or sizing balloons to measure pulmonary artery pressure accurately. 23 patients (82% of the cohort) advanced to Fontan completion. In this group, median mPAP dropped from 20.5 (IQR 19-22) mmHg to 13 (IQR 12-14) mmHg post-test (p < 0.001). Median PVR post-test was 1.8 (IQR 1.5-2.1) WUm2. SpO2 levels decreased from a median of 88% (IQR 86%-93%) pre-test to 80% (IQR 75%-84%) post-test (p < 0.001). In five patients, elevated mPAP post-test occlusion on diagnostic catheter angiography led to non-completion of Fontan circulation. In this group, median pre- and post-test mPAP were 23mmHg (IQR 21.5-23.5) and 19mmHg (IQR 18.5-20), respectively (p = 0.038). Median post-test PVR was 3.8 (IQR 3.6-4.5) WUm2. SpO2 levels decreased from a median of 79% (IQR 76%-81%) pre-test to 77% (IQR 73.5%-80%) post-test (p = 0.039). Our study presents a specialized approach for patients initially deemed unsuitable for Fontan due to elevated pulmonary artery pressures. We were able to successfully complete the Fontan procedure in the majority of these high-risk cases after temporary balloon occlusion test.

Pulmonary arteries growth after bidirectional cavopulmonary connection in functionally univentricular heart program

The optimization of the pulmonary arteries (PA) size is an important concern after the bidirectional cavopulmonary connection (BDCPC) in patients with functionally univentricular heart as it precedes the completion of the Fontan program. We analyzed the PA growth between the time of the BDCPC and the time of the total cavopulmonary connection (TCPC) in a large monocentric cohort of children, and we explored the factors associated with differential growth profiles. In total, 118 patients (median age at the BDCPC 8 months (IQR 5–18)) were included. Diameters of the right and the left PA were measured proximally to the first lobar bifurcation on the pulmonary artery angiography obtained before BDCPC and compared to angiographies obtained before TCPC. Nakata index was also calculated using these two measurements. Associations of pertinent covariables with the PA growth were explored. Both pulmonary artery branches grew between BDCPC and TCPC (9.1 mm of diameter (IQR 7.2–12.2) to 12.2 mm (IQR 9.9–14.4) for right PA; P < 0.0001, 8.5 mm of diameter [db1] (IQR 6.5–7.3) to 9.6 mm (IQR 8.0–12.4) for left PA; P = 0.0001). However, PA branches growth was not proportional to child's growth as we noted a decrease of the Nakata index over this period. The main factor associated with a better PA branch growth was the presence of an additional pulmonary blood flow through a pulsatile antegrade flow (+28.2 mm 2 of section area for right PA; P = 0.020, +16.8 mm 2 for left PA; P = 0.043). No other factor preceding BDCPC or associated procedure performed simultaneously had an impact on PA branch growth. PA branches growth is reduced after BDCPC and this may hamper the functioning of the future TCPC. Maintaining a pulsatile antegrade blood flow whenever possible could optimize PA growth and prevent deleterious early remodeling of the pulmonary vascular bed.

Is More Better or Is Less More?

In staged palliation for single-ventricle congenital heart disease, the debate over whether adding or maintaining an additional source of pulmonary blood flow (APBF) at the time of the superior cavopulmonary connection (SCPC) has waged for several decades. All studies addressing this topic had retrospective single-center designs with heterogeneous patient populations. These studies commonly use surgeon preference as the indication to add, maintain, or eliminate APBF at SCPC. In one metaanalysis, the methodology used for some of these analyses was judged to be poor. 1 Alghamdi A.A. Bidirectional Glenn with additional pulmonary blood flow: systematic review and evidence-based recommendations. J Card Surg. 2015; 30: 724-730 Crossref PubMed Scopus (5) Google Scholar Not surprisingly, the findings from this collective work have been inconsistent. For example, proponents of adding APBF to SCPC cite higher peripheral oxygen saturations (Spo2) after the SCPC, improved pulmonary artery (PA) growth during the interval between SCPC and Fontan completion, and intentionally delaying Fontan surgery to allow for somatic growth as benefits of this strategy. 2 Ferns S.J. El Zein C. Multani K. et al. Is Additional pulsatile pulmonary blood flow beneficial to patients with bidirectional Glenn?. J Thorac Cardiovasc Surg. 2013; 145: 451-454 Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar ,3 Gray R.G. Altmann K. Mosca R.S. et al. Persistent antegrade pulmonary blood flow post-Glenn does not alter early post-Fontan outcomes in single-ventricle patients. Ann Thorac Surg. 2007; 84: 888-893 Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar However, the oxygen saturation difference between patients with and without APBF at SCPC is typically clinically modest and may become indistinguishable before the Fontan procedure. Data to show that any measured increase in PA size with APBF is sustained after the Fontan procedure or improves Fontan outcomes in the long term are lacking. Moreover, any extended time for somatic growth between SCPC and the Fontan operation in the patients with APBF would a priori allow for PA growth as well. Therefore, the link between preserved APBF at SCPC and durable benefit or sustained improved outcomes is weak on the basis of available information. Influence of Antegrade Pulmonary Blood Flow on Outcomes of Superior Cavopulmonary ConnectionThe Annals of Thoracic SurgeryVol. 114Issue 5PreviewWe sought to characterize short- and long-term outcomes after superior cavopulmonary connection (SCPC) in children eligible for inclusion of antegrade pulmonary blood flow (APBF) in the SCPC circuit, exploring whether maintaining APBF was associated with outcomes. Full-Text PDF

The impact of additional antegrade pulmonary blood flow at bidirectional Glenn shunt on long-term outcomes

ObjectivesWe investigated the impact of additional antegrade pulmonary blood flow on the long-term outcomes after bidirectional Glenn shunt. MethodsFrom 2001 to 2015, 279 patients underwent bidirectional Glenn shunt as an interim palliation for a functionally single ventricle. After excluding patients with a previous Kawashima or Norwood operation, 202 patients with preexisting antegrade pulmonary blood flow before bidirectional Glenn shunt were included in this study. Antegrade pulmonary blood flow was eliminated in 110 patients (no antegrade pulmonary blood flow group) and maintained in 92 patients (antegrade pulmonary blood flow group). The impact of antegrade pulmonary blood flow at bidirectional Glenn shunt on long-term outcome was analyzed using inverse probability of treatment weighting. ResultsMedian age and body weight at bidirectional Glenn shunt were 8 months and 7.8 kg, respectively. Prolonged chest tube drainage or readmission for effusion after bidirectional Glenn shunt was more frequent in the antegrade pulmonary blood flow group (odds ratio, 3.067; 95% confidence interval, 1.036-9.073; P = .043). In the no antegrade pulmonary blood flow group, B-type natriuretic peptide level was decreased further until the Fontan operation (P = .012). In the no antegrade pulmonary blood flow group, oxygen saturation was lower just after bidirectional Glenn shunt, although it was increased further until Fontan operation (P < .001), despite still lower oxygen saturation before Fontan operation compared with antegrade pulmonary blood flow group (P < .001). The McGoon ratio was decreased in both groups without intergroup difference, although the McGoon ratio before Fontan operation was higher in the antegrade pulmonary blood flow group (2.3 ± 0.4 vs 2.1 ± 0.4, P = .008). Overall transplant-free survival was worse in the antegrade pulmonary blood flow group (hazard ratio, 2.37; confidence interval, 1.089-5.152; P = .030). ConclusionsMaintaining antegrade pulmonary blood flow at bidirectional Glenn shunt was beneficial for higher oxygen saturation and larger pulmonary artery size before Fontan operation. However, it was unfavorable for overall transplant-free survival with a sustained higher risk of death or transplant until the elimination of antegrade pulmonary blood flow.

Long-term results of additional pulmonary blood flow with bidirectional cavopulmonary shunt

ObjectiveWe evaluated additional pulmonary blood flow at the time of bidirectional cavopulmonary shunt and its effects on the Fontan procedure and long-term outcome of Fontan circulation and liver function.MethodsWe included 22 patients (16 boys, 6 girls) having undergone bidirectional cavopulmonary shunt with additional pulmonary blood flow between April 2002 and January 2016. Mean age and body weight were 20 ± 13 months and 7.5 ± 6.5 kg, respectively. We retrospectively evaluated the patients’ clinical data, including cardiac catheterization data, liver function, and liver fibrosis markers.ResultsAll patients were alive with a New York Heart Association status of I at the long-term follow-up. Changes between pre-bidirectional cavopulmonary shunt and 101 months after the Fontan procedure included the following: the cardiothoracic ratio of chest X-ray decreased from 52.2 ± 3.9% to 41.8 ± 5.9% (p < 0.001); systemic ventricle end-diastolic pressure decreased from 11.4 ± 3.2 mmHg to 6.9 ± 3.6 mmHg (p < 0.001); and the pulmonary artery index decreased from 485.1 ± 272.3 to 269.5 ± 100.5 (p = 0.02). Type IV collagen, hyaluronic acid, and procollagen levels increased over the normal range 116 months after the Fontan procedure.ConclusionsThe additional pulmonary blood flow at the time of bidirectional cavopulmonary shunt may contribute to pulmonary arterial growth at the Fontan procedure with low pulmonary arterial resistance and without ventricle volume overload. The Fontan circulation was well-maintained at the long-term follow-up, while liver fibrosis markers were above their normal values.

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.

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

The difference between extreme Tetralogy of Fallot (T4F) and pulmonary atresia with ventricle septal defect (PA/VSD) is the anterograde pulmonary blood flow. It is speculated that the association of modified Blalock-Taussig shunt (mBTs) and additional pulmonary blood flow favours shunt thrombosis but promotes better pulmonary arterial (PA) growth. This study sought to compare (PA) growth after mBTs shunt between T4F and AP/VSD. From 1995 to 2018, 79 mBTs were performed in infants (< 1 years), 45 for T4F and 34 for AP/VSD. Using a 1:1 propensity score match analysis, 38 patients were included ( n = 19 in each group). The primary outcome was operative mortality, mBTs thrombosis, and PA growth. After matching, the preoperative Nakata was similar (101 ± 8 mm 2 /m 2 in T4F; 106 ± 8 in AP/VSD P = 0.75 ). The age and weight were similar (24,3 ± 5 days, 3.3 ± 0.5 kg in T4F; 24,15 ± 4, 3.3 ± 0.9 in AP/VSD P = 0.84 and P = 0.77 respectively ). The mBTs size was similar (4.15 ± 0.5 mm in T4F; 4.3 ± 0.5 in PA/VSD P = 0.35). There was no difference in in-hospital mortality ( n = 0, in T4F; n = 2, 11% in AP/VSD, P = 0.14) and mBTs thrombosis (3,16% in T4F; 2,11% in AP/VSD, P = 0.18). The time to extubation tended to be longer in T4F (5 ± 1days vs. 2 ± 1 P = 0.06). The left and right PA diameter at time of biventricular repair were similar (7.5 ± 0.5 mm, 7 ± 0.2 in T4F; 8.1 ± 0.7 mm, 7 ± 1 in AP/VSD P = 0.43 and P = 0.78, Fig. 1 ) and the Nakata delta (112 ± 23 mm 2 /m 2 in T4F; 110 ± 17 in AP/VSD P = 0.78). Median time to complete repair was the same in the PA/VSD (12.26 [3.9-25] months) compared with T4F (9.7 [6.2–41.1] months) P = 0.87). The interstage reintervention were similar (3.16% in T4F; 4.22% in AP/VSD , P = 0.9 ). Anterograde blood flow with mBTs did not increase the risk of mBTs thrombosis. We could not show benefit of anterograde blood flow with mBTS versus mBTS for pulmonary arteries growth. Anterograde blood flow did increase the time to extubation, probably by increasing total pulmonary blood flow.

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

The difference between extreme Tetralogy of Fallot (T4F) and pulmonary atresia with ventricle septal defect (PA/VSD) is the anterograde pulmonary blood flow. It is speculated that the association of modified Blalock-Taussig shunt (mBTs) and additional pulmonary blood flow favours shunt thrombosis but promotes better pulmonary arterial (PA) growth. This study sought to compare (PA) growth after mBTs shunt between T4F and AP/VSD. From 1995 to 2018, 79 mBTs were performed in infants (< 1 years), 45 for T4F and 34 for AP/VSD. Using a 1:1 propensity score match analysis, 38 patients were included ( n = 19 in each group). The primary outcome was, mBTs thrombosis, PA growth and operative mortality. After matching, the preoperative Nakata was similar (101 ± 8 mm 2 /m 2 in T4F; 106 ± 8 in AP/VSD P = 0.75). The age and weight were similar (24,3 ± 5 days, 3.3 ± 0.5 kg in T4F; 24,15 ± 4, 3.3 ± 0.9 in AP/VSD P = 0.84 and P = 0.77 respectively). The mBTs size was similar (4.15 ± 0.5 mm in T4F; 4.3 ± 0.5 in PA/VSD P = 0.35) There was no difference in in-hospital mortality ( n = 0, in T4F; n = 2,11% in AP/VSD, P = 0.14) and mBTs thrombosis (3,16% in T4F; 2,11% in AP/VSD, P = 0.18). The time to extubation tended to be longer in T4F (5 ± 1days vs. 2 ± 1 P = 0.06). The left and right PA diameter at time of biventricular repair were similar (7.5 ± 0.5 mm, 7 ± 0.2 in T4F; 8.1 ± 0.7 mm, 7 ± 1 in AP/VSD P = 0.43 and P = 0.78, Fig. 1 , Fig. 2 ) and the Nakata delta (112 ± 23 mm 2 /m 2 in T4F; 110 ± 17 in AP/VSD P = 0.78). Median time to complete repair was the same in the PA/VSD (12.26 [3.9–25] months) compared with T4F (9.7 [6.2–41.1] months) P = 0.87. The interstage reintervention were similar (3,16% in T4F; 4,22% in AP/VSD, P = 0.9). Anterograde blood flow with mBTs did not increase the risk of mBTs thrombosis. We couldn’t show benefit of anterograde blood flow with mBTS versus mBTS for pulmonary arteries growth. Anterograde blood flow did increase the time to extubation, probably by increasing total pulmonary blood flow.

Microcatheter-assisted stenting of the tortuous vertical ductus arteriosus via femoral access in a duct-dependent pulmonary circulation

BackgroundStenting of the patent ductus arteriosus (PDA) has been accepted as alternative option to surgical shunting to enable additional pulmonary blood flow or for palliation of patients with a truly duct-dependent pulmonary circulation. The procedure can be challenging given the variable and often tortuous anatomy of the PDA and various technical approaches are reported. ObjectiveTo report an alternative technique to treat tortuous ducts with microcatheter assistance and by transfemoral approach. MethodsWe applied this technique of PDA stenting in 5 consecutive patients (4/5 age < 1 week, weight 2,7–3,2 kg; 1/5 re-do PDA stenting at 6,5 month and 5,9 kg). A soft coronary guidewire was advanced by microcatheter assistance into the branch pulmonary arteries and thereafter replaced by an extrastiff guidewire to enable the placement of long coronary stents. ResultsSuccessful PDA stenting with this stepwise approach and with femoral access only could be achieved in all patients (n = 5/5). A single stent was used in 2 patients (one with re-do stenting and previous stents). 3/5 patients had 2 stents implanted by telescopic technique. Stent sizes used were 4,5 × 15 mm (n = 2) and 4,5 × 18 mm (n = 6). No guide wire or stent dislodgement appeared through all procedures with microcatheter assistance. ConclusionsThis technique enables PDA stenting via transfemoral approach in complex and tortuous ducts and thereby offers an attractive addition to the interventional management of truly duct-dependent pulmonary circulation.

Targeted Increase in Pulmonary Blood Flow in a Bidirectional Glenn Circulation

In patients with a Glenn shunt and unilateral pulmonary vascular abnormalities, supplemental pulmonary blood flow may improve antegrade flow in the target lung and may permit eventual Fontan completion, while mitigating the risks of uncontrolled additional flow to the contralateral lung. We attempted this by inserting a small aortopulmonary shunt into the affected pulmonary artery and banding the central pulmonary artery. We performed a retrospective review of all patients who underwent this procedure from 2000 to 2015. Comparisons of nonparametric variables were performed with the Wilcoxon signed rank test. Twenty patients were followed for a median of 36 months. Vascular abnormalities included recalcitrant unilateral pulmonary arterial (n = 8) or venous (n = 5) obstruction or hypoplasia, combined disease (n = 4), or abundant aortopulmonary collaterals (n = 3). Nine had retrograde flow from the affected lung. The most frequent complications were pleural effusions (n = 4) and shunt thrombosis (n = 4). Postoperatively, all patients demonstrated antegrade flow to the target lung at the earliest postoperative catheterization. Glenn pathway pressures and saturations were unchanged, whereas the shunted pulmonary arterial oxygen saturation and pressure increased by 4% (P = 0.04) and 6mmHg (P = 0.04), respectively. Three patients died; 9 achieved definitive palliation, 4 were deemed to have no improvement, and 4 continue to have a contralaterally shunted Glenn at this time. Targeted additional pulmonary blood flow may be useful for the palliation of single ventricle patients with abnormal pulmonary vasculature. However, morbidity and mortality are common in this high-risk population.

TARGETED INCREASE IN PULMONARY BLOOD FLOW IN A BIDIRECTIONAL GLENN CIRCULATION

Background: Additional pulmonary blood flow (PBF) into a Glenn shunt improves oxygenation at the risk of veno-venous collaterals, effusions, and Superior Vena Cava (SVC) hypertension. In select patients with unilateral pulmonary vascular abnormalities, targeted supplemental PBF may improve antegrade

Early to mid-term results after total cavopulmonary connection performed in the second decade of life.

Total cavopulmonary connection (TCPC) performed in the second decade of life has rarely been studied. Thus, we investigated (bicentric study) early and late morbidity and mortality following completion of TCPC in these patients. From January 1999 to June 2014, 63 patients (14.5 ± 2.9 years) underwent TCPC (extracardiac conduit). Palliation before completion was an isolated bidirectional cavopulmonary shunt (BCPS) in 3 patients or BCPS associated with additional pulmonary blood flow (APBF) that was either antegrade (Group 1) in 38 (63%) or retrograde (Group 2) in 22 (37%). Preoperative and perioperative data were reviewed retrospectively. Mean pulmonary arterial and ventricular end-diastolic pressures were 12.2 and 9.2 mmHg, respectively. Mean Nakata index was 279 ± 123 and 228 ± 87 mm 2 /m 2 in Groups 1 and 2, respectively ( P = 0.01). Aortic cross-clamping was performed in 22 from Group 1 and 8 from Group 2 ( P = 0.04). Mean follow-up was 4.57 years [0.8-15]. Nine patients had prolonged stays in the intensive care unit (>6 days). There were 1 early and 2 late deaths (non-cardiac related). Actuarial survival was 96% at 4 years. At last follow-up, single-ventricle function remained normal or improved in all patients (Group 1) compared to 82% in Group 2 ( P = 0.02). New York Heart Association (NYHA) class had improved in both groups: 47 patients were NYHA class II and 16 class III preoperatively vs 50 class I and 10 class II postoperatively ( P < 0.001). Single-ventricle palliation with BCPS and APBF allowed completion of TCPC in the second decade of life, with encouraging mid-term results. However, BCPS with retrograde APBF was associated with single-ventricle dysfunction: thus, this technique needs to be used cautiously as long-lasting palliation.

Bidirectional cavopulmonary anastomosis with additional pulmonary blood flow: good or bad pre-Fontan strategy

This study aimed to evaluate the influence of preserved additional pulmonary blood flow (APBF) on survival after bidirectional cavopulmonary shunt (BCPS) and completion of Fontan circulation. From March 2003 and April 2015, 156 patients with a single ventricle underwent BCPS. After performing propensity score analysis (1:1) for the entire sample, 50 patients with APBF (APBF group) were matched with 50 patients without APBF (no-APBF group). Age ( P = 0.90), sex ( P = 0.57), weight ( P = 0.75), single ventricle morphology ( P = 0.87), type of neonatal palliative procedure ( P = 0.52), saturation ( P = 0.35), ejection fraction ( P = 0.90), Nakata index ( P = 0.70) and mean pulmonary artery pressure ( P = 0.72) were not significantly different between the groups. No significant survival difference was demonstrated ( P = 0.54). One and 4-year survival rates were both 89.1% ± 4.6% in the APBF group and 87.2% ± 4.9% and 83.4% ± 5.9%, respectively, in the no-APBF group. There was no significant difference in rates of Fontan completion ( P = 0.24), which was achieved in 22 patients from the APBF group (55.0%) and 26 patients from the no-APBF group (65.0%). However, Fontan completion occurred significantly earlier in the no-APBF group ( P < 0.01). In this group, Fontan procedure was performed before 36 months of inter-stage period in 45.9% ± 8.5% of cases (95% CI 31.0-63.7%) compared to only 13.3 ± 5.6% (95% CI 5.8-29.1%) in the APBF group. Our study demonstrates that APBF does not affect survival after BCPS or Fontan completion rate. APBF allows postponing the Fontan procedure without a negative effect on clinical status.

Staged Left Ventricular Recruitment and Biventricular Conversion for Patients With Borderline Left Heart

A borderline left heart may be present in patients with hypoplastic left heart syndrome or an unbalanced atrioventricular canal defect. Traditionally, such patients have been managed either by high-risk biventricular repair in infancy or during the neonatal period, or by definitive single-ventricle palliation. In this article, we present an approach for staged left ventricular recruitment that promotes gradual rehabilitation of left heart structures and allows delay in the commitment to either a single-ventricle pathway or a biventricular pathway. The rationale, techniques, and early results are described.

The effects of leaving additional pulmonary blood flow in combination with bidirectional cavopulmonary anastomosis on early outcomes

Background:­ This study aims to assess the effects of additional pulmonary blood flow on the early outcomes of patients who underwent bidirectional cavopulmonary anastomosis due to single

Bidirectional Glenn With Additional Pulmonary Blood Flow: Systematic Review and Evidence-Based Recommendations.

The aim of this report was to review the exiting literature to date to inform clinical decision-making regarding the additional pulmonary blood flow at the time of bidirectional Glenn procedure.

The effects of dexmedetomidine administration on the pulmonary artery pressure and the transpulmonary pressure gradient after the bidirectional superior cavopulmonary shunt.

The hemodynamic effects of dexmedetomidine (DEX) on pulmonary artery pressure (PAP) are not fully understood in patients with a single-ventricle physiology. The objective of this retrospective study was to characterize the effect of perioperative DEX infusion on PAP and the transpulmonary pressure gradient after a bidirectional superior cavopulmonary shunt (BCPS) operation. We retrieved physiologic data including the heart rate, incidence of cardiac pacing, systolic and diastolic arterial blood pressure (ABP), and superior vena cava (SVC) and inferior vena cava (IVC) pressures from the medical records of all patients <12 months of age who underwent a BCPS operation. Patients with an additional Norwood or Damus-Kaye-Stansel procedure, those with additional pulmonary blood flow, and those without both a SVC and an IVC catheter were excluded from the present study. Following the BCPS operation, the SVC pressure is equivalent to the PAP. Similarly, the IVC pressure is equivalent to the common atrial pressure (CAP). Accordingly, we can directly assess the transpulmonary pressure gradient, defined as the difference between the PAP and the CAP, using simultaneous SVC and IVC pressure measurements. Twenty-nine patients were included in the present study. We did not find any increase in the PAP, CAP, PAP/systolic ABP ratio, or the transpulmonary pressure gradient as of 6 h after admission to the intensive care unit when the patients were treated with DEX infusion at a median (interquartile ranges) dose of 0.6 mcg/kg/h (0.4, 0.64 mcg/kg/h). We concluded that the administration of DEX to children with a single-ventricle physiology is acceptable.

Long-term outcomes of common atrioventricular valve plasty in patients with functional single ventricle

Common atrioventricular valve (CAVV) regurgitation is widely known as a risk factor for mortality and Fontan completion in patients with functional single ventricle. Hence, we reviewed our surgical experience with CAVV plasty in Fontan candidates. Staged Fontan strategy and extracardiac total cavopulmonary connection as Fontan modification were our principal approaches in 1995. Since then, 38 consecutive Fontan candidates (21 males, median weight at operation was 7.0 kg and median age was 17 months old) underwent CAVV plasty. Right atrial isomerism was associated with 24 patients. The initial CAVV plasty was performed before inter-stage bidirectional Glenn (BDG) in 3 patients, at BDG in 23, before Fontan in 4 and during Fontan in 8. Since 1995, the modified Alfieri technique with a tailed, expanded, polytetrafluoroethylene tube as a bridging strip was the procedure for repair and 27 patients underwent the procedure. The mean follow-up period was 7.1 years (range 0-17 years). Actuarial survival and freedom from CAVV replacement rates at 1, 5 and 10 years were 81, 70 and 67% and 89, 85 and 75%, respectively. Seven patients ultimately underwent CAVV replacement with one death. Twenty-three of the 38 patients completed Fontan operation (61%). Association with total anomalous pulmonary venous connection (P= 0.01) and CAVV plasty before BDG (P= 0.05) were risk factors for mortality. CAVV plasty for patients with functional single ventricle is still challenging; however, the aggressive and repeated surgical intervention may contribute to provide better life-prognosis. The ventricular volume unloading effect of BDG without additional pulmonary blood flow or Fontan operation did not contribute to maintain CAVV function. Therefore, there would not be any hesitation for CAVV replacement to control CAVVR in the setting of systemic ventricular failure. Although the statistically significant therapeutic superiority of the modified Alfieri technique was not shown so far, further follow-up may reveal the advantage of this easy and simple technique.

Glenn bidireccional: resultados y análisis de factores de riesgo en una experiencia de 5 años

Bidirectional Glenn shunt is a palliative surgical procedure in patients with single ventricle. Although morbimortality in this surgery is low, risk factors have been described. The purpose of this study is to report our outcomes in Glenn surgery, identifying mortality risk factors in our population. Retrospective study between 2005 and 2009. Age, weight, previous surgery, surgical procedure, and postoperative condition were analyzed. Results are reported as median and rank, or absolute values and percentage. Uni and multivariate analysis was made to identify risk factors of mortality and/or prolonged hospitalization (Stata 9.0). One hundred and one patients were operated; 87 bidirectional Glenn and 14 bilateral Glenn. Median age 15 months (2.5-108), median weight 8.5 kg (4.2-27), and 74% of them with previous surgery. In 54 patients an associated procedure was performed simultaneously, only in 4 additional pulmonary blood flow was left. Median hospitalization was 8 days (2-97). Thirty-five percent of the patients presented complications. No association between age, weight, pulmonary hypertension, cardiopulmonary bypass, cross clamping, associated procedures or Glenn bilateral with mortality or morbidity was found. Overall mortality was 3.9%. Mortality was similar to other centers, but morbidity in this group of patients is high. No independent risk factors associated with morbidity or mortality were identified.

Results of Additional Pulsatile Pulmonary Blood Flow with Bidirectional Glenn Cavopulmonary Anastomosis: Positive Effect on Main Pulmonary Artery Growth and Less Need for Fontan Conversion

Additional antegrade pulsatile pulmonary blood flow obtained by leaving the main pulmonary artery patent during bidirectional cavopulmonary shunt has been shown to give additional benefits to the bidirectional Glenn cavopulmonary anastomosis. We retrospectively evaluated our 20-patient pulsatile Glenn series in order to find out whether these salutary effects were valid or not. Between June 2007 and November 2011, 20 patients (11 girls and 9 boys) with single-ventricle physiology underwent bidirectional cavopulmonary anastomosis. The additional source of blood flow was through the unligated main pulmonary artery in all patients. A retrospective review of our surgical experience was performed focusing on the role of additional pulmonary flow. Medical records and perioperational and postoperative follow-up data including clinical outcomes were retrospectively retrieved and analyzed. Two patients died in the early postoperative period. One patient died in the follow-up period. Mean follow-up time was 23.9 ± 15.7 months. No superior vena cava syndrome and no increase in pulmonary vascular resistance were observed. Improvement of partial oxygen pressure after pulsatile Glenn has been shown in all patients (P = .00). At a mean interval of 22.9 months, main pulmonary artery size continued to increase after pulsatile Glenn cavopulmonary anastomosis (P = .028). Only 1 patient was converted to Fontan type circulation after pulsatile Glenn cavopulmonary anastomosis. The pulsatile cavopulmonary shunt is a useful procedure in the early and intermediate term management of patients with a functional univentricular heart. It improves partial oxygen pressure and the impact of pulsatility on the main pulmonary artery.