Influence of competitive pulmonary blood flow on the bidirectional superior cavopulmonary shunt. A multi-institutional study

Pulsatile Glenn as long-term palliation for single ventricle physiology patients

OBJECTIVE

There are limited studies analyzing pulsatile Glenn as a long-term palliation strategy for single ventricle patients. This study sought to determine their outcomes at a single institution.

DESIGN

A retrospective review was performed.

SETTING

Study performed at a single pediatric hospital.

PATIENTS

All single ventricle patients who underwent pulsatile Glenn from 1995 to 2016 were included.

OUTCOME MEASURES

Pulsatile Glenn failure was defined as takedown, transplant, or death. Further palliation was defined as Fontan, 1.5, or biventricular repair. Risk factors were assessed by Cox multivariable competing risk analyses.

RESULTS

Seventy-eight patients underwent pulsatile Glenn at age 9 months (interquartile range, 5-14). In total, 28% had heterotaxy, 18% had a genetic syndrome, and 24% had an abnormal inferior vena cava. There were 3 (4%) perioperative mortalities. Further palliation was performed in 41 (53%) patients with a median time-to-palliation of 4 years (interquartile range, 3-5). Pulsatile Glenn failure occurred in 10 (13%) patients with 8 total mortalities. Five- and 10-year transplant-free survival were 91% and 84%, respectively. At a median follow-up of 6 years (interquartile range, 2-8), 27 patients (35%) remained with PG (age 7 years [interquartile range, 3-11], oxygen saturation 83% ± 4%). Preoperative moderate-severe atrioventricular valve regurgitation (AVVR) (hazard ratio 7.77; 95% confidence interval 1.80-33.43; P =.005) and higher pulmonary vascular resistance (hazard ratio 2.59; 95% confidence interval 1.08-6.15; P =.031) were predictors of pulsatile Glenn failure after adjusting for covariates. Reaching further palliation was less likely in patients with preoperative moderate-severe AVVR (hazard ratio 0.22, 95% confidence interval 0.08-0.59; P =.002).

CONCLUSION

Pulsatile Glenn can be an effective tool to be used in challenging circumstances, these patients can have a favorable long-term prognosis without reducing their suitability for further palliation.

Numerical Investigation of the Effect of Additional Pulmonary Blood Flow on Patient-Specific Bilateral Bidirectional Glenn Hemodynamics

The effect of additional pulmonary blood flow (APBF) on the hemodynamics of bilateral bidirectional Glenn (BBDG) connection was marginally discussed in previous studies. This study assessed this effect using patient-specific numerical simulation. A 15-year-old female patient who underwent BBDG was enrolled in this study. Patient-specific anatomy, flow waveforms, and pressure tracings were obtained using computed tomography, Doppler ultrasound technology, and catheterization, respectively. Computational fluid dynamic simulations were performed to assess flow field and derived hemodynamic metrics of the BBDG connection with various APBF. APBF showed noticeable effects on the hemodynamics of the BBDG connection. It suppressed flow mixing in the connection, which resulted in a more antegrade flow structure. Also, as the APBF rate increases, both power loss and reflux in superior venae cavae (SVCs) monotonically increases while the flow ratio of the right to the left pulmonary artery (RPA/LPA) monotonically decreases. However, a non-monotonic relationship was observed between the APBF rate and indexed power loss. A high APBF rate may result in a good flow ratio of RPA/LPA but with the side effect of bad power loss and remarkable reflux in SVCs, and vice versa. A moderate APBF rate could be favourable because it leads to an optimal indexed power loss and achieves the acceptable flow ratio of RPA/LPA without causing severe power loss and reflux in SVCs. These findings suggest that patient-specific numerical simulation should be used to assist clinicians in determining an appropriate APBF rate based on desired outcomes on a patient-specific basis.

Bidirectional Cavopulmonary Shunt with Accessory Pulmonary Blood Flow

Ninety-five patients underwent a bidirectional cavopulmonary shunt between 1995 and 1999. Group 1 (n = 38) had a shunt without an additional source of pulmonary blood flow. Group 2 (n = 57) had a shunt with accessory pulmonary flow. Patients with accessory pulmonary flow were better palliated (82% asymptomatic in group 2 versus 63% in group 1; p = 0.03). Intensive care stay was longer in group 2 (6.9 ± 7.5 days versus 4.6 ± 3.6 days; p = 0.05). There were no differences between the groups in terms of early postoperative oxygen saturation, incidence of pleural effusion, or the need for inotropic support. Leaving an additional source of pulmonary blood flow in selected patients is recommended. These findings are of special significance in developing countries where additional surgery is often unaffordable and a bidirectional cavopulmonary shunt may be the only procedure undertaken.

Does the persistence of pulsatile antegrade pulmonary blood flow following bidirectional Glenn procedure affect long term outcome?

OBJECTIVES

To evaluate outcomes of the Glenn procedure with or without pulsatile antegrade pulmonary blood flow during palliation of patients with functionally single ventricles.

METHODS

The clinical records of 111 consecutive patients who underwent a bidirectional Glenn procedure for palliation of single ventricle morphologies at our institution between 1997 and 2010 were reviewed. We specifically excluded infants with the diagnosis of hypoplastic left heart syndrome. Following the Glenn procedure, there were 57 patients (Group 1) with and 54 (Group 2) without antegrade pulmonary blood flow. We reviewed their long term data from our database to determine whether the presence of forward flow after the Glenn procedure affected outcome.

RESULTS

There was 1 early hospital death (in Group 1). The mean SaO2 at discharge was higher in Group 1 (83%±2 vs 78%±4; P<0.001). There was no difference in duration of chest drain insertion, length of intensive care and hospital stay between the two groups. The median follow-up time was 7.1 years (range, 1.7-14.9 years). Sixty-five patients underwent Fontan completion (35 from Group 1) a median of 3.6 years (Group 1) and 3.3 (Group 2) after the Glenn procedure. Three patients died following Fontan completion (1 from Group 1). The 5- and 10-year survival (95% CI) was 96% (84-98%) and 96% (84-98%) in Group 1, and 88% (74-94%) and 82% (66-91%) in Group 2, respectively (log-rank; P=0.03). There was no significant difference in SaO2 levels, or incidence of systemic atrioventricular valve regurgitation or ventricular dysfunction in survivors between groups at the last follow-up.

CONCLUSIONS

We conclude that leaving antegrade flow following a Glenn procedure improves oxygen saturation significantly and while it does not impact on short term outcome or hospital stay, long-term outcome is significantly better.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Intact right ventricle-pulmonary artery shunt after stage 2 palliation in hypoplastic left heart syndrome improves pulmonary artery growth

For patients with hypoplastic left heart syndrome who have undergone the Norwood procedure with a right ventricle-pulmonary artery (RV-PA) shunt, the shunt can either be removed or left intact at the time of the stage 2 procedure. This study aimed to determine the effects of an intact shunt on pulmonary artery growth and clinical outcomes after the stage 2 procedure. A retrospective review of patients who underwent Norwood with an RV-PA shunt from 2005 to 2010 was performed. Catheterization data, echocardiographic data, postoperative outcome variables, and mortality data were collected. Pulmonary artery size was measured at pre-stage 2 and pre-Fontan catheterizations using the Nakata Index and the McGoon Ratio. Of the 68 patients included in the study, 48 had the shunt removed at the time of stage 2 (group 1), and 20 had the shunt left intact (group 2). The two groups did not differ in terms of pre-stage 2 hemodynamics or pulmonary artery size. After stage 2, group 2 had higher oxygen saturations. The two groups did not differ regarding duration of chest tube drainage, length of hospital stay, need for unplanned interventions, or mortality. Before Fontan, the group 2 patients had higher superior vena cava (SVC) pressures and more venovenous collaterals closed. There was increased pulmonary artery growth between the pre-stage 2 and pre-Fontan catheterizations in group 2 using both the Nakata Index (+148.5 vs -52.4 mm(2)/m(2); p = 0.01) and the McGoon Ratio (+0.36 vs +0.01; p = 0.01). These findings indicate that patients with an intact RV-PA shunt after stage 2 have greater pulmonary artery growth than patients with the shunt removed, with no increased risk of complications.

Common carotid artery to internal jugular vein shunt for managing hypoxemia after a cavopulmonary shunt

In the present report, we discuss a patient who developed persistent hypoxemia after an attempt at Fontan completion failed. As a bail-out procedure, a left common carotid artery to left internal jugular vein shunt was constructed, after which the hypoxemia was relieved.

Right ventricular stiffness constant as a predictor of postoperative hemodynamics in patients with hypoplastic right ventricle: a theoretical analysis

One and a half ventricle repair (1.5VR) is a surgical option for hypoplastic right ventricle (RV). The benefits of this procedure compared to biventricular repair (2VR) or Fontan operation remain unsettled. To compare postoperative hemodynamics, we performed a theoretical analysis using a computational model based on lumped-parameter state-variable equations. We varied the RV stiffness constant (B (RV)) to simulate the various RV hypoplasia, and estimated hemodynamics for a given B (RV). With B (RV) < 150% of normal, cardiac output was the largest in 2VR. With B (RV) > 150%, cardiac output became larger in 1.5VR than in 2VR. With B (RV) > 250%, RV end-diastolic volume was almost the same between 1.5VR and 2VR, and a rapid increase in atrial pressure precluded the use of 1.5VR. These results indicate that the beneficial effect of 1.5VR depends on the RV stiffness constant. Determination of management strategy should not only be based on the morphologic parameters but also on the physiological properties of RV.

Transcatheter occlusion of antegrade pulmonary flow in children after cavopulmonary anastomosis

OBJECTIVE

To report our experience with transcatheter occlusion of antegrade pulmonary blood flow (APF) for postoperative complications of cavopulmonary anastomosis (BCPA).

BACKGROUND

It has been suggested that limited APF enhances pulmonary arterial growth in patients undergoing BCPA. However, APF may result in suboptimal postoperative hemodynamics and sequelae such as SVC syndrome or prolonged chest tube drainage. For this subgroup, closure of APF may alleviate these problems.

METHODS

All BCPA procedures where APF was left open from 1995-2005 were reviewed. Symptomatic patients with APF who underwent a cardiac catheterization in the postoperative period comprised the study cohort.

RESULTS

179 BCPA procedures were performed during the study period. APF was left patent in 29/179. 6/29 patients (age 10-28 months, median 14 months) presented 12 to 130 day; (median 31 days) with persistent pleural effusions (5) or SVC syndrome (1, Five had a history of a previous pulmonary arterial band (PAB) and one pulmonary stenosis. PA pressure was elevated in all (range 17-27 mmHg; median 22 mmHg). Hemodynamic evaluation with temporary APF occlusion was repeated in all patients. APF was successfully closed in 4/6 patients. The Amplatzer POA occluder was used in 3 and the Amplatzer ASD occluder in 1. Pulmonary effusions resolved in all the patients who had transcatheter APF closure as did the case of SVC syndrome. There were no complications.

CONCLUSION

Transcatheter APF occlusion seems both safe and feasible in patients with hemodynamic compromise following BCPA with residual APF. Temporary occlusion testing prior to permanent device closure is recommended.

Persistent antegrade pulmonary blood flow post-glenn does not alter early post-Fontan outcomes in single-ventricle patients

BACKGROUND

The bidirectional Glenn cavopulmonary anastomosis (BDG) represents the standard interim procedure in treatment of patients with single-ventricle physiology. Anterograde pulmonary blood flow (APBF) maintained after BDG has been shown both to improve and to complicate postoperative clinical course. We studied its effects on outcome after BDG and eventual Fontan completion.

METHODS

From November 1995 to November 2005, 60 patients underwent BDG and Fontan. All patients had APBF from the ventricle to the pulmonary artery at time of BDG. In group 1 (n = 39) APBF was maintained after BDG, whereas APBF was interrupted at BDG in group 2 (n = 21). Cardiac catheterization data, interstage morbidity, and postoperative outcome variables were recorded.

RESULTS

Pre-BDG hemodynamics differed only in that the mean pulmonary artery pressure was higher in group 2 (17.0 +/- 4.4 mm Hg) than in group 1 (13.8 +/- 4.5 mm Hg; p = 0.03). There were no differences between groups 1 and 2 in BDG outcome variables. At pre-Fontan catheterization, group 1 had higher mean pulmonary artery pressure (13.3 versus 10.9 mm Hg, p = 0.01), arterial oxygen saturation (85.8 versus 80.9%, p = 0.0001), and fewer collateral vessels were coil embolized than in group 2 (0.9 versus 1.6, p = 0.02). Mean ventricular end-diastolic pressure was similar between groups. The Nakata index in group 1 remained stable from pre-BDG to pre-Fontan (348 versus 391, p = 0.24), but it decreased in group 2 (375 versus 227, p = 0.046).

CONCLUSIONS

Patients with anterograde pulmonary blood flow after BDG had a modest increase in pulmonary artery growth and arterial oxygen saturations, and decreased collateral vessel formation. This did not, however, confer additional benefit on outcome after BDG or on eventual Fontan completion.

Single ventricle palliation: Greater risk of complications with the Fontan procedure than with the bidirectional Glenn procedure alone

BACKGROUND

This study was performed to evaluate and compare the early, intermediate, and long-term outcomes of the bidirectional Glenn procedure and Fontan procedure in patients who live at moderately high altitude.

METHODS

The outcome of each method of palliation for patients with a functionally single ventricle was retrospectively evaluated from a review of medical records.

RESULTS

The bidirectional Glenn procedure was performed in 177 patients from October 1984 to June 2004. The Fontan procedure was performed in 149 patients from June 1978 to June 2004. Cardiovascular death or heart transplantation occurred in 8% of patients after the bidirectional Glenn procedure and 17% of patients after the Fontan procedure. Complications of systemic thromboembolic events, bleeding associated with anticoagulation therapy, protein losing enteropathy, and arrhythmias requiring implantation of a pacemaker, cardioversion, or radiofrequency ablation occurred in 7% of patients after the bidirectional Glenn procedure and 47% of patients after the Fontan procedure. Cardiovascular deaths and heart transplantation occurred less frequently when the Fontan procedure was performed in patients with a previous bidirectional Glenn procedure. However, the actuarial transplant-free survival and freedom from complications was not superior for a subgroup of patients who had a Fontan procedure after a bidirectional Glenn procedure in comparison to a subgroup of patients who had a bidirectional Glenn procedure alone.

CONCLUSIONS

The bidirectional Glenn procedure can be used for long-term palliation of patients with a functionally single ventricle. Additional palliation with a Fontan procedure may increase the risk of stroke, protein losing enteropathy and arrhythmias without improving survival.

Management of systemic venous anomalies in the pediatric cardiovascular surgical patient

Systemic venous anomalies are rare and heterogeneous entities. Although these anomalies are rare in the general population, they occur more frequently in the subpopulation with congenital heart disease. In and of themselves, most of these lesions have no physiologic significance. However, in the setting of congenital heart disease these lesions may significantly alter surgical treatment. This review is dedicated to these lesions.

Pulmonary artery growth fails to match the increase in body surface area after the Fontan operation

OBJECTIVE

To evaluate the growth of the pulmonary arteries after a Fontan procedure.

DESIGN

Retrospective review.

SETTING

Two paediatric cardiology tertiary care centres.

PATIENTS

61 children who underwent a modified Fontan operation and had angiography suitable for assessment of pulmonary artery size before the Fontan procedure and during long term follow up. An atriopulmonary connection (APC) was present in 23 patients (37.7%) and a total cavopulmonary connection (TCPC) was present in 38 (62.3%). Postoperative angiograms were performed 0.5-121 months (median 19 months) after the Fontan operation.

MAIN OUTCOME MEASURE

Growth of each pulmonary artery measured just before the first branching point. The diameter was expressed as a z score with established nomograms used to standardise for body surface area.

RESULTS

The mean change in the preoperative to postoperative z scores of the right pulmonary artery was -1.06 (p = 0.004). The mean change in the preoperative to postoperative z scores of the left pulmonary artery was -0.88 (p = 0.003). Changes in the preoperative to postoperative z scores were more pronounced in the patients undergoing APC than TCPC, especially for the right pulmonary artery.

CONCLUSION

After the Fontan operation, growth of the pulmonary arteries often fails to match the increase in body surface area.

Is morbidity influenced by staging in the fontan palliation? A single center review

In a retrospective study of 32 consecutive patients undergoing a total cavopulmonary connection (TCPC), we tried to determine if the trend for decreasing age at Fontan completion and reducing the intervals between the staged procedures during the past decade was associated with a change in morbidity and outcome. In 8 patients the Fontan circulation was completed in one stage and in 24 patients an intermediate step by hemi-Fontan or bidirectional cavopulmonary anastomosis was performed before Fontan completion. Mean age at TCPC and mean interval since the previous palliation have decreased significantly during the past decade. Although major complications were significantly reduced over time the occurrence and duration of postoperative pleural effusions were not. Decreasing age as well as intervals in staged Fontan palliation have beneficial influence on major complications and outcome, without significantly affecting the duration of pleural effusions at Fontan completion.

Additional Pulmonary Blood Flow Has No Adverse Effect on Outcome After Bidirectional Cavopulmonary Anastomosis

BACKGROUND

Controversy continues over whether additional sources of pulmonary blood flow are beneficial in combination with a bidirectional cavopulmonary anastomosis. We have therefore assessed the effects of additional pulmonary blood flow on outcome after bidirectional cavopulmonary anastomosis.

METHODS

From 1996 to 2000, 106 patients underwent bidirectional cavopulmonary anastomosis, either isolated (group 1, n = 54), or with additional pulmonary blood flow through the pulmonary artery (group 2, n = 30) or a Blalock-Taussig shunt (group 3, n = 22).

RESULTS

Superior vena cava syndrome was more frequent in group 2 and less in groups 1 and 3 (p < 0.05). Low-output syndrome was more frequent in group 2 and less in group 3 (p = 0.01). Repeated-measures analysis of variance showed higher oxygen saturations with additional pulmonary blood flow (p < 0.05) and significant changes over time (p < 0.0001). Pulmonary pressures, systemic ventricular fractional shortening, end-diastolic diameter index, end-diastolic pressure, and atrioventricular valve regurgitation remained unaffected by additional pulmonary blood flow. Pulmonary artery pressures were lower in group 2 than 3 (p < 0.05). Fractional shortening (p < 0.05) and atrioventricular valve regurgitation (p < 0.0001) changed significantly over time. Fractional shortening showed a strong trend toward different changing patterns with or without additional pulmonary blood flow (p = 0.055), and atrioventricular valve regurgitation showed different changing patterns among the groups (p < 0.005). End-diastolic diameter and pulmonary artery dimensions, which were smaller than normal, remained unchanged. In logistic regression, smaller body surface area at bidirectional cavopulmonary anastomosis, single ventricle, and bidirectional cavopulmonary anastomosis with a Blalock-Taussig shunt were associated with early death. Actuarial survival including total cavopulmonary connection did not differ among groups (p = 0.96).

CONCLUSIONS

We conclude that additional pulmonary blood flow has no adverse effect on outcome after cavopulmonary anastomosis. Additional flow through the main pulmonary artery offers different advantages and disadvantages concerning perioperative complications and pulmonary artery growth compared with additional flow through a Blalock-Taussig shunt.

Effects of controlled antegrade pulmonary blood flow on cardiac function after bidirectional cavopulmonary anastomosis

BACKGROUND

Bidirectional cavopulmonary anastomosis (BCPA) has been used as an intermediate stage in the treatment of patients with single-ventricle physiology. Leaving additional antegrade pulmonary blood flow has been shown to improve postoperative arterial blood oxygen saturations; however, controversy continues over whether the potential increase in systemic venous pressure is detrimental. We studied the effects of controlled antegrade pulmonary blood flow on cardiac function in patients after BCPA.

METHODS

From January 1993 to July 2000, 128 patients underwent BCPA. Mean age at operation was 6.2 +/- 4 months (range 2 to 36 months). In group 1 (n = 72), restricted antegrade pulmonary blood flow was maintained through a native narrowed pulmonary valve or by adjustment of previously placed pulmonary artery band with the goal of maintaining the mean pulmonary artery pressure less than 16 mm Hg. In group 2 (n = 56), BCPA was the only source of pulmonary blood flow.

RESULTS

One hospital death (0.8%) occurred. The mean pulmonary artery pressure at the end of the operation was 13 +/- 2 mm Hg in group 1 compared with 12 +/- 2 mm Hg in group 2, a difference that was not significant. Patients in group 1 had higher arterial oxygen saturations (84% +/- 3% compared with 74% +/- 3% in group 2, p < 0.05), and shorter mean hospital stay (9 +/- 3 days compared with 15 +/- 2 days, p < 0.05). Persistent pleural effusion (> 10 days) or late chylothorax occurred in 4 patients from group 1 and 3 from group 2, a difference that was not significant. During a mean follow-up of 36 +/- 10 months no late deaths occurred. The mean oxygen saturation remained higher in group 1, 80% +/- 3% compared with 74% +/- 4% in group 2, and the hematocrit was lower, at 38% +/- 3% compared with 46% +/- 4% (p < 0.05 for both comparisons). Cardiac catheterizations were performed in 68 patients before completion Fontan. Total pulmonary artery (Nakata) index was 263 +/- 34 mm(2)/m(2) in group 1 (n = 40) and 188 +/- 13 mm(2)/m(2) in group 2 (n = 28) (p < 0.05). The mean pulmonary artery pressure and mean ventricular end-diastolic pressure were similar.

CONCLUSIONS

Controlled antegrade pulmonary blood flow may have favorable effects on cardiac function for a selected group of patients and does not appear to have adverse effects on subsequent suitability for completion Fontan.

Pulmonary arteriovenous malformations after cavopulmonary anastomosis

Pulmonary arteriovenous malformations (PAVMs) are a cause of progressive cyanosis after cavopulmonary anastomosis in children with single ventricle physiology who are on the pathway leading to a Fontan procedure. Investigations into possible mechanisms for the etiology of PAVMs are ongoing and suggest that the liver might play a key regulatory role in the development of these lesions.

The ratio of flow in the superior and inferior caval veins after construction of a bidirectional cavopulmonary anastomosis in children

In patients who have undergone a superior cavopulmonary anastomosis, the superior caval venous flow provides the only, or the most important, pulmonary blood supply, while the inferior caval venous blood is not oxygenated, being mixed with the pulmonary venous blood before entering the systemic circulation. In healthy children, the contribution of superior caval venous flow to total cardiac output has been shown to decrease during growth. Patients who have undergone a superior cavopulmonary anastomosis, however, often have a higher oxygen saturation than predicted by the age-matched ratio of superior to inferior caval venous flows. This study was designed, therefore, to assess the ratio of flows in the superior and inferior caval veins subsequent to a superior cavopulmonary anastomosis. We carried out 18 magnetic resonance imaging studies with velocity-mapping and heart catheterisations so as to assess the contribution of superior caval venous flow to total cardiac output. Patients were divided into 3 groups according to their age. There were five aged from 8 to 24 months, eight aged from 24 to 48 months, and five older than 48 months. No significant difference could be found in the ratios of superior-to-inferior caval venous flow, nor of superior caval venous-to-systemic flow, between the 3 groups. The ratio of venous flows was 0.89 +/- 0.34 in those aged from 8 to 24 months, 1.09 +/- 0.42 in those from 24 to 48 months, and 1.25 +/- 0.27 in the older patients (F analysis of variance 1.06, p 0.37). The ratio of superior caval venous-to-systemic flow was 0.46 +/- 0.08 in the youngest patients, 0.50 +/- 0.09 in those aged from 24 to 48 months, and 0.55 +/- 0.05 in the older patients (F analysis of variance 0.76, p 0.49). These findings suggest that the hemodynamics of a cavopulmonary anastomosis may affect the normal decrease of superior caval venous flow with age. This could be related to a redistribution of flow, with a proportionally higher flow to the head and upper body after construction of a superior cavopulmonary anastomosis. Since increasing cyanosis and progressive exercise intolerance are the main indications for creation of a total cavopulmonary connection, these findings should be taken into account when determining the timing for completion of the Fontan circulation.

[The bidirectional Glenn operation in 100 cases with complex congenital heat diseases: factors influencing surgical results]

OBJECTIVE

The bidirectional Glenn shunt is a well established surgical technique in children with complex congenital heart disease. The present study is a retrospective analysis of patients undergoing this operation in order to assess the influence of different variables in the outcome.

PATIENTS AND METHOD

From December 1990 to June 2000, 100 patients received a bidirectional Glenn shunt. Two groups were defined, based on the outcome. Group A (n = 15, unsuccessfully result) including death and need to reoperate, and Group B (n = 85, patients with good outcome).

RESULTS

The mortality was 8%. Eight patients were reoperated at follow-up. The survivors were followed for a mean of 3.5 years. Mean pulmonary artery pressure 7 mmHg was a factor associated with poor clinical progress. Other variables (age less than 1 year, excessive pulmonary blood flow, double Glenn operation, significant anatomic anomalies, and arrythmias), were also associated with outcome. Significant variations were observed in the time of by-pass or the need for aortic clamp in cases with simultaneous operative repair of pulmonary branch stenosis. Actuarial survival rate, most more than 1 year was 92%, and freedom from reoperation at 3 years was 90%.

CONCLUSIONS

The bidirectional Glenn shunt is an excellent palliation in patients with functionally single ventricle. Mean pulmonary artery pressure was the most important variable related with the outcome. We are encouraged to continue with tendency to perform bidirectional Glenn shunt preferably early, avoiding, whenever possible, previous palliative surgery.

The short- and mid-term results of bidirectional cavopulmonary shunt with additional source of pulmonary blood flow as definitive palliation for the functional single ventricular heart

OBJECTIVE

The purpose of this study was to demonstrate the early and late outcomes of bidirectional cavopulmonary shunt (BCPS) as a definitive procedure for the functional single ventricular heart.

METHOD

From September 1991 to December 1997, 34 patients underwent a BCPS procedure without a routine conversion to Fontan circulation. The additional source of pulmonary blood flow was left in all patients. Conversion was performed only when it was required for excessive cyanosis.

RESULTS

The hospital mortality rate was 8.8% (3/34, 95% confidence limit; 1.9-23%) and the 5-year survival rate was 75% for a mean follow-up period of 33+/-22 months. Seven patients underwent a conversion procedure for remnant or recurrent cyanosis and deterioration of exercise tolerance. Four of these patients died after conversion to Fontan circulation. Twenty-five long-term survivors with BCPSs maintained an arterial oxygen saturation of 84+/-6.1%, and 52% of them had a normal exercise tolerance or mild limitation. No patients developed severe late complications other than recurrent cyanosis.

CONCLUSION

Due to the high mortality after conversion to Fontan circulation in patients whose conditions had deteriorated, we could not demonstrate the clear superiority of long-term BCPS over the construction of Fontan circulation for management of the functional single ventricular heart. If deteriorated conditions were successfully managed in the late period, the outcome of long-term BCPS would have been better.

Improved results with selective management in pulmonary atresia with intact ventricular septum

OBJECTIVE

Late outcome of neonatal pulmonary atresia with intact ventricular septum remains poor in most reported series. We have followed a selective approach toward either single ventricle repair versus complete or partial biventricular repair based on the presence of right ventricle-dependent coronary circulation and growth of the right ventricle.

METHODS

A retrospective chart review was conducted of 47 patients who underwent surgery between January 1991 and September 1998.

RESULTS

Sixteen (34%) patients had a right ventricle-dependent coronary circulation, with a tricuspid valve Z-score of -3.0 +/- 0.66 versus -2.0 +/- 0.95 (P =.002) for those without a right ventricle-dependent coronary circulation. A systemic-pulmonary artery shunt only was performed in all patients with a right ventricle-dependent coronary circulation, with 1 death. Fourteen of 16 patients with a right ventricle-dependent coronary circulation underwent a bidirectional Glenn shunt at a median of 9 months after their first operation, 9 of whom have had a Fontan procedure (no deaths). In the 31 (66%) patients without a right ventricle-dependent coronary circulation, 6 patients underwent only a systemic-pulmonary artery shunt, 23 had a shunt and right ventricular decompression, and 2 had only a transannular patch. In this group, 10 patients received a 2-ventricle repair, 6 a 1. 5-ventricle repair, and 8 patients had a Fontan procedure. There was 1 early death and the overall survival was 98% at 1 year, 5 years, and 7 years.

CONCLUSIONS

If patients are stratified well, excellent survival can be achieved in the treatment of pulmonary atresia with intact ventricular septum. This result may be at the price of achieving a 1-ventricle as opposed to a 2-ventricle repair.

Bi-directional cavopulmonary shunt: is accessory pulsatile flow, good or bad?

OBJECTIVE

Evaluation of the effect and long-term outcome of accessory pulsatile blood flow versus classical bi-directional cavopulmonary connection (BCPC).

METHODS

Retrospective review of the medical and surgical records.

RESULTS

Two-hundred and five patients (119 boys, 86 girls) underwent BCPC from 1990 to 1996. Accessory pulsatile flow was present in 68%, flow being maintained through the pulmonary trunc in 46%, systemic-to-pulmonary artery shunt in 13% and mixed in 7%, or patent ductus arteriosus in 2%. Patients with accessory pulsatile flow had lower hospital mortality (3% versus 5%), while mean pulmonary artery pressure (14.1 versus 12.6 mmHg P = 0.050) and increase of oxygen saturation (12.4 versus 8.7, P = 0.034) were significantly higher. The period of artificial ventilation (1.9 day) and ICU stay (6 days) did not differ for both groups. Late mortality was higher following accessory pulsatile flow (6% versus 1%). At late follow-up patients with accessory pulsatile flow had significantly higher oxygen saturation (mean 85 +/- 4%, versus 79 +/- 4%; P < or = 0.005). If subsequent completion of Fontan is considered the optimal palliation and subsequent systemic to pulmonary artery shunt, arteriovenous fistula and transplantation is considered a failure, patients with accessory pulsatile flow had significantly more and earlier completion of the Fontan procedure (mean 1.7 +/- 2.4 years, versus 2.7 +/- 4.4 years; P = 0.008). Survival is not influenced by age at bi-directional cavopulmonary shunt surgery, left or right functional ventricular anatomy or previous palliative surgery. One patient with accessory pulsatile flow developed systemic-to-pulmonary collateral's eventually requiring lobectomy.

CONCLUSION

Despite two different initial palliative techniques the outcome was not significantly different. Accessory pulsatile blood flow appeared not to be a contra-indication for a completion Fontan procedure. Moreover, the data suggest that after accessory pulsatile flow can safely be performed, at late follow-up oxygen saturation is higher, while, significantly more and earlier completion of Fontan occurred. Age at bi-directional cavopulmonary shunt, basic left or right ventricular anatomy or previous palliative surgery did not influence survival.

The real fate of pulmonary arteries after bidirectional superior cavopulmonary anastomosis: is there a need for concern?

Controversy remains about the growth of the pulmonary arteries following a bidirectional superior cavopulmonary anastomosis in children with complex cyanotic congenital cardiac malformations. This is partially due to the morphological heterogeneity of the patients, and partially due to methodological differences in series published so far. It is further complicated by the variable use, in different centres, of additional sources of pulmonary blood flow. We believe that the fate of these arteries preoperatively is significantly influenced by the amount of pulmonary blood flow and the initial size of the arteries. Separate assessment of the pulmonary arterial development postoperatively is recommended for those who, initially, had relatively small as opposed to larger than normal pulmonary arteries. Measurement of the diameters of both pulmonary arteries just prior to their first point of branching, together with the use of Z-score evaluation rather than the Nakata index, is discussed. It remains to be established whether, over time, the bidirectional cavopulmonary anastomosis is effective in developing adequately the pulmonary arteries in preparation for an ultimate total cavopulmonary connection, or even as isolated long-term palliation. A prospective, multi-institutional study involving sequential non-invasive assessment of pulmonary arterial development (using, for example, magnetic resonance imaging) is required to solve the outstanding problems.

Evaluation and management of pulmonary atresia with intact ventricular septum

Pulmonary atresia with intact ventricular septum (PA/IVS) is a spectrum of diseases with varying severity of right ventricle hypoplasia and potential for biventricular, univentricular, or hybrid repairs. Pessimistic outcome measures for PA/IVS may give way to optimism with the refinement of early diagnosis and early intervention to encourage right ventricle flow and optimize growth. To this end, PA/IVS has become a focus of innovative interventions (e.g., fetal surgery) and new catheter-based and surgical techniques.

Additional pulmonary blood flow with the bidirectional Glenn anastomosis: does it make a difference?

BACKGROUND

The bidirectional cavopulmonary shunt has become a mainstay in the palliation of patients with a functional single-ventricle heart. However, there remain a number of unresolved issues regarding this procedure, many of which concern the response of the pulmonary vasculature to this unique circulatory physiology. Among the issues of debate are the role and effects of an additional source of pulmonary blood flow.

METHODS

Between January 1990 and April 1997, 160 patients underwent bidirectional cavopulmonary anastomosis. Median age at operation was 7.8 months, and age ranged from 24 days to 43 years. An additional source of pulmonary blood flow was included in 93 patients (58%). A retrospective review of our experience with this cohort was performed with a focus on the role of additional pulmonary blood flow.

RESULTS

Eight patients (5%) died in the early postoperative period, and the overall early failure rate (death or take-down) was 7.5% (n=12). Eleven other patients underwent early reoperation to decrease (n=8) or increase (n=3) the amount of pulmonary blood flow. Early survivors were followed up for a median of 23 months, during which time 5 patients died and 30 patients underwent Fontan completion. Including early and late mortality, actuarial survival rates at 1 and 2 years were 91% and 88%, respectively.

CONCLUSIONS

The bidirectional cavopulmonary shunt is a useful procedure in the early or intermediate-term management of patients with a functional univentricular heart. However, there is much still to be learned about this unique physiologic system. The role of accessory pulmonary blood flow remains unclear, as does the use of the bidirectional cavopulmonary shunt as long-term palliation. Pulmonary arteriovenous fistulas are a serious concern, especially in young patients with heterotaxy syndrome.

Partial biventricular repair for complex congenital heart defects: an intermediate option for complicated anatomy or functionally borderline right complex heart

BACKGROUND

Partial biventricular repair consists of bidirectional cavopulmonary anastomosis in the presence of separated systemic and pulmonary circulations, with antegrade flow of inferior caval return through an intact or reconstructed pulmonary outflow tract. This versatile procedure may be used as a definitive repair for patients with a functional right heart complex incapable of supporting an entire cardiac output or in patients with complicated anatomy.

METHODS

From July 1992 to April 1997, 23 patients (median age 5.2 years) underwent partial biventricular repair. In 15 of these cases the entire repair, including bidirectional cavopulmonary anastomosis, intracardiac repair, and right ventricular outflow reconstruction, was performed as a planned procedure at our institution. The other eight patients had previously been placed on a Fontan track and had undergone bidirectional cavopulmonary anastomosis; their circulations were converted to a partial biventricular circulation.

RESULTS

There were no early deaths. Complete atrioventricular block developed in two patients with straddling tricuspid valve. At a median follow-up of 17 months, there were no late deaths and three patients had undergone reintervention. Partitioning of the pulmonary arteries to create a classic Glenn anastomosis with antegrade flow to the left lung was performed in one case; another patient underwent an atrial septectomy, and the third patient required revision of tricuspid valve repair. All patients are in New York Heart Association functional class I.

CONCLUSIONS

Partial biventricular repair is a versatile strategy that can be used to manage a variety of forms of complex congenital heart disease. Cases for which the repair is useful include those in which complete biventricular repair is unlikely to be achieved because of limited size or function of the right side of the heart and those in which a patient with a ventricle capable of supporting inferior vena caval return was previously placed on a Fontan track.

New approach in partial cavopulmonary connection

The development of pulmonary arteriovenous fistulas after bidirectional cavopulmonary operations, such as the bidirectional Glenn shunt and Kawashima's procedure, has raised concern. Development of these fistulas, which are more frequent than initially thought, can represent a limiting factor in the late outcome of these patients and may even limit the indication for these types of surgery. Whether the fistulas can be reversed by transforming the surgical procedures has yet to be established. In the hope of avoiding this kind of complication, thought to be caused by the lack of passage of a hypothetical hepatic factor through the pulmonary circulation, we have developed an inverted type of bidirectional cavopulmonary connection in which the blood coming from the liver perfuses immediately both lungs. This is made possible by shunting via an intra-atrial tunnel the blood from the superior caval vein directly to the left atrium, and the blood from the inferior caval vein to the right branch of the pulmonary trunk (keeping its bifurcation intact). We describe findings in two patients undergoing successful surgery with this technique. Serial follow-up with contrast echocardiography did not show evidence of arteriovenous pulmonary fistulas. Despite our numbers being small, and the time of follow-up being limited, we believe that it is important to document these and similar cases.

Systemic venous collateral channels causing desaturation after bidirectional cavopulmonary anastomosis: evaluation and management

OBJECTIVES

We sought to characterize the frequency, anatomic details and factors associated with the development of collateral channels between the superior and inferior vena caval systems after bidirectional cavopulmonary anastomosis.

BACKGROUND

It is well known that systemic venous collateral channels often develop in patients who have undergone a classic Glenn shunt or bidirectional cavopulmonary anastomosis and that such collateral channels can lead to profound systemic desaturation. However, there have been few reports focusing on this problem.

METHODS

Fifty-four patients (median age 1.4 years) who underwent bidirectional cavopulmonary anastomosis and had preoperative and postoperative angiograms available for review were studied retrospectively. Postoperative connections between the superior and inferior vena caval systems were identified and measured. Sites of collateral origin and entry from the superior and inferior venous systems, as well as the course taken in between, were recorded.

RESULTS

At follow-up angiography performed 17 days to 46 months postoperatively, a total of 31 venous collateral channels were observed in 18 patients with a wide variety of primary morphologic diagnoses. The majority of these collateral channels (80%) originated from the brachiocephalic vein or its junction with the superior vena cava, and over half of them drained below the diaphragm. In patients who developed venous collateral channels, the mean transpulmonary pressure gradient early after bidirectional cavopulmonary anastomosis was higher (p = 0.005), and mean arterial oxygen saturation at follow-up was lower (p = 0.009). There were trends toward higher superior vena caval pressure early after the operation and at follow-up in patients with collateral channels and a higher likelihood of absent upper lobe pulmonary blood flow in these patients. Successful coll embolization of 10 collateral channels was performed in six patients, with a median increase in arterial oxygen saturation of 16%.

CONCLUSIONS

Angiographically detectable systemic venous collateral channels develop after bidirectional cavopulmonary anastomosis in a substantial number of patients (33% in the present series) with a variety of forms of a functional univentricular heart. Patients with venous collateral channels can be treated successfully with coil embolization, but the indications for embolization will depend on individual circumstances.

Outcomes after bidirectional cavopulmonary shunt in infants less than 6 months old

OBJECTIVES

We sought to assess the results after bidirectional cavopulmonary shunt (BCPS) in infants < 6 months old and to identify risk factors for poor outcome.

BACKGROUND

Although BCPS is a well established procedure for the palliation of patients with a single-ventricle heart, there have been very few reports of outcomes after BCPS in young infants.

METHODS

Since 1990, 42 infants between 0.8 and 6.0 months of age (mean [+/-SD] 3.7 +/- 1.4) have undergone BCPS for primary (n = 16) or secondary (n = 26) palliation of tricuspid atresia (n = 13), hypoplastic left heart syndrome (n = 10) or other forms of functional single-ventricle heart (n = 19). Accessory pulmonary blood flow was included in 18 patients. Preoperative and perioperative data were gathered on retrospective review of patient records, and follow-up was conducted by means of direct physician contact or record review.

RESULTS

The overall hospital mortality rate, including that associated with reoperations, was 4.8% (2 of 42 patients). Seven patients (17%) required reoperation related to the BCPS or pulmonary blood flow in the early postoperative period: Procedures included take-down of the BCPS in four patients, with one early death, and procedures to decrease pulmonary blood flow in three patients. Age < 1 month correlated significantly with early death and with early failure of the BCPS (death or take-down). Follow-up of the 37 patients discharged with intact BCPS was obtained at a mean +/-SD of 14.3 +/- 11.3 months postoperatively, during which time three patients died (at 6.5 +/- 2.5 months). The 2-year actuarial survival rate for patients undergoing BCPS at < 6 months of age was 86%. Overall freedom from death or take-down (including early and late events) was significantly lower in patients < 2 months old than in those > 2 months old. Four patients have undergone successful Fontan completion (18.3 +/- 2.9 months postoperatively), and one patient whose BCPS was taken down subsequently underwent successful restoration of a BCPS.

CONCLUSIONS

Outcomes after BCPS in young infants are comparable to those in older infants and children. However, our current preference is to defer this procedure until after 2 months of age.