Effect of Fenestration on Early Postoperative Outcome in Extracardiac Fontan Patients with Different Risk Levels

Preoperative N-terminal pro-brain natriuretic peptide is associated with Fontan outcomes

OBJECTIVE

The role of preoperative N-terminal pro-brain natriuretic peptide level in patient outcomes after the Fontan operation remains unclear.

METHODS

The medical records of all patients who underwent their first Fontan operation from June 2011 to October 2019 in our tertiary referral pediatric cardiac center were retrospectively reviewed. Preoperative hemodynamic factors and N-terminal pro-brain natriuretic peptide were analyzed to test the association of mortality and morbidity.

RESULTS

We enrolled 110 patients (men/women 62/48; median age, 4.1 [3.4, 5.8] years; median follow-up period, 4.28 [2.31, 6.71] years). Almost all operations were extracardiac conduits (98.2%). Primary outcomes of death, Fontan takedown, and heart transplantation were observed in 9 patients (8.2%). Abnormal ventricular contractility, elevated preoperative pulmonary artery pressure, high pulmonary vascular resistance index, and high log₁₀ N-terminal pro-brain natriuretic peptide level were associated with poor outcomes.

SECONDARY OUTCOMES

atrioventricular valve regurgitation moderate or greater, elevated pulmonary artery pressure, high pulmonary vascular resistance index, and high log₁₀ N-terminal pro-brain natriuretic peptide level were associated with rehospitalization due to heart failure. Multivariable Cox regression analysis revealed that log₁₀ N-terminal pro-brain natriuretic peptide was the only significant predictor of all primary and secondary outcomes. A scoring system including factors of pulmonary artery pressure, pulmonary vascular resistance index, and N-terminal pro-brain natriuretic peptide was established, and the risk stratification is associated with outcomes after the Fontan operation.

CONCLUSIONS

High preoperative N-terminal pro-brain natriuretic peptide was associated with poor outcomes after the Fontan operation.

Risk factors and outcomes associated with acute kidney injury following extracardiac total cavopulmonary connection: a retrospective observational study

BACKGROUND

Total cavopulmonary connection (TCPC) is an important operation for the treatment of complex congenital heart disease. Epidemiology and outcomes for pediatric patients with acute kidney injury (AKI) following extracardiac TCPC have not been well documented. This study investigates the prevalence, risk factors, and outcomes of AKI in children after extracardiac TCPC surgery.

METHODS

We retrospectively evaluated patients (age at surgery <18 years) who underwent extracardiac TCPC surgery between January 2008 and January 2020 in the Pediatric Cardiac Surgical Center of Fuwai Hospital, Beijing, China. AKI was defined according to the pediatric-modified risk, injury, failure, loss of function, and end-stage renal disease criteria.

RESULTS

A total of 377 pediatric patients were included in this study; 123 patients (32.6%) had some degree of AKI. Among the patients with AKI, 101 (82.1%) were diagnosed with AKI-risk (AKI-R), while 22 (17.9%) were diagnosed with acute kidney injury/failure (AKI/F) (16 with AKI, and 6 with AKF). Preoperative estimated creatinine clearance (OR: 1.039, 95% CI: 1.024-1.055, P<0.001), neutrophil-to-lymphocyte ratio (OR: 1.208, 95% CI: 1.128-1.294, P<0.001), and renal perfusion pressure (OR: 0.962, 95% CI: 0.938-0.986, P=0.002) on postoperative day (POD) 0 were significantly associated with AKI after TCPC. Having previously undergone a bidirectional Glenn was significantly associated with the severity of postoperative AKI (OR: 0.253, 95% CI: 0.088-0.731, P=0.011). Furthermore, AKI was associated with prolonged mechanical ventilation time, prolonged intensive care unit stay, and composite adverse outcome. Compared with non-AKI patients, the 10-year survival rate of patients with severe AKI was significantly lower (95.5% vs. 65.9%, P=0.009).

CONCLUSIONS

Although the incidence of AKI was high in patients undergoing TCPC surgery, most cases were AKI-R. Severe AKI was significantly associated with early adverse outcomes and poor long-term survival.

Early outcomes of fenestrated intra-extracardiac Fontan procedure: Insights, experiences, and expectations

BACKGROUND

Intraextracardiac Fontan procedure (FP) aimed to combine the advantages of lateral tunnel and extracardiac conduit modifications of the original technique. Herein, we present our early outcomes in patients with intraextracardiac fenestrated FP.

METHODS

A retrospective analysis was performed to evaluate intraextracardiac fenestrated Fontan patients between 2014 and 2021. Seventeen patients were operated on with a mean age and body weight of 9.1 ± 5.5 years and 28.6 ± 14.6 kg.

RESULTS

Sixteen patients (94%) were palliated as univentricular physiology with hypoplasia of one of the ventricles. One patient (6%) with well-developed two ventricles with double outlet right ventricle and complete atrioventricular septal defect had straddling of the chordae prohibiting a biventricular repair. All of the patients had cavopulmonary anastomosis before Fontan completion, except one case. Fenestration was performed in all cases. Postoperative mean pulmonary artery pressures and arterial oxygen saturation levels at follow-up were 10 ± 2.4 mmHg and 91.3 ± 2.7%, respectively. Mean duration of pleural drainage was 5.4 ± 2.3 days. All of the fenestrations are patent at a mean follow-up period of 4.8 ± 7.7 years, except one case. Any morbidity and mortality were not encountered.

CONCLUSIONS

Early outcomes of intraextracardiac fenestrated FP are encouraging. This procedure may improve the results in a patient population who should be palliated as univentricular physiology, especially in cases with complex cardiac anatomy.

Case report and review of the literature: Successful transition from acute continuous veno-venous hemodiafiltration therapy to chronic peritoneal dialysis in a chronically ventilated child with hypoplastic left heart syndrome following fontan

Fontan palliation depends on low pulmonary vascular resistance in order to maintain pulmonary blood flow and adequate oxygenation. This physiology results in higher central venous pressures with limited renal perfusion pressure and cardiac output. Positive pressure ventilation with mechanical ventilation increases intrathoracic pressure and raises central venous pressure and can further limit pulmonary and renal perfusion. Fluid removal with intermittent hemodialysis can be challenging in Fontan patients and can cause intolerable hypotension, however the increased abdominal filling pressures during peritoneal dialysis dwells can exacerbate systemic venous hypertension seen in Fontan patients and threaten adequate pulmonary blood flow and cardiac output. Successful transition to peritoneal dialysis in a chronically ventilated patient with hypoplastic left heart syndrome, end-stage renal disease and Fontan physiology has not been described. We present details outlining the successful transition across multiple modalities of renal replacement therapy to assist other teams faced with similar challenges in chronically ventilated Fontan patients with end-stage renal disease.

Pulmonary vascular disease in Fontan circulation-is there a rationale for pulmonary vasodilator therapies?

The Fontan circulation is a palliative concept for patients with univentricular hearts. The central veins are connected directly to the pulmonary arteries (cavo-pulmonary connection) to separate the pulmonary and the systemic circulation. There is no sub-pulmonary ventricle that generates pressure to drive blood through the pulmonary arteries. Pulmonary blood flow is determined by central venous pressure (CVP) and pulmonary vascular resistance (PVR). The capability of the Fontan circulation to compensate for alterations in PVR is limited, as CVP can only be increased within narrow ranges without adverse clinical consequences. Consequently, systemic ventricular preload and cardiac output are dependent on a healthy lung with low PVR. Failure of the Fontan circulation is relatively common. In addition to ventricular dysfunction, maladaptive pulmonary vascular remodeling resulting in increased pulmonary resistance may play a key role. The pathophysiology of the maladaptive vascular processes remains largely unclear and diagnosis of an increased PVR is challenging in Fontan circulation as accurate measurement of pulmonary arterial blood flow is difficult. In the absence of a sub-pulmonary ventricle, pulmonary artery pressure will almost never reach the threshold conventionally used to define pulmonary arterial hypertension. There is a need for markers of pulmonary vascular disease complementary to invasive hemodynamic data in Fontan patients. In order to treat or prevent failure of the Fontan circulation, pathophysiological considerations support the use of pulmonary vasodilators to augment pulmonary blood flow and systemic ventricular preload and lower CVP. However, to date the available trial data have neither yielded enough evidence to support routine use of pulmonary vasodilators in every Fontan patient nor have they been helpful in defining subgroups of patients that might benefit from such therapies. This review discusses potential pathomechanisms of pulmonary vascular disease; it summarizes the current knowledge of the effects and efficacy of pulmonary vasodilator therapy in Fontan patients and tries to outline areas of potential future research on the diagnosis and treatment of pulmonary vascular disease and Fontan failure.

Risk Factors and Long-Term Prognosis for Chylothorax After Total Cavopulmonary Connection in Children: A Retrospective Study From a Single Center

Background: Chylothorax is a severe complication after total cavopulmonary connection (TCPC) in children. This study was performed to evaluate the incidence, risk factors, and short- and long-term prognosis for chylothorax. Methods: We retrospectively reviewed the electronic records of patients who underwent TCPC between January 2008 and December 2020 in Fuwai Hospital. Patients were divided into two groups based on the occurrence of post-operative chylothorax. Univariate and multivariate analyses were performed to identify risk factors, and long-term survival was estimated by the Kaplan-Meier method. Results: Of 386 patients included in our study, chylothorax occurred in 60 patients (15.5%). Compared with the non-chylothorax group, the prevalence of prolonged intensive care unit (ICU) stay (p = 0.000) and post-operative hospital stay (p = 0.000) were greater in patients with chylothorax. Post-operative adverse events in terms of infection (p = 0.002), ascites (p = 0.001), prolonged pleural effusion (p = 0.000), and diaphragmatic paralysis (p = 0.026) were more frequent in chylothorax patients. The median follow-up duration was 4.0 (2.0, 6.8) years. The chylothorax group had significantly lower survival rates at 1 year (92.4 vs. 99.3%, p < 0.001) and 10 years (84.6 vs. 91.6%, p < 0.001), respectively. Having a right dominant ventricle [odds ratio (OR) = 2.711, 95% confidence interval (CI) = 1.285-5.721, p = 0.009] and a higher peak central venous pressure (CVP) on post-operative day (POD) 0 (OR = 1.116, 95% CI = 1.011-1.233, p = 0.030) were the risk factors for the development of chylothorax after TCPC operation. Conclusion: The incidence of chylothorax in patients undergoing TCPC is lower than previously reported but is associated with poor early- and long-term survival. Having a right dominant ventricle and a higher peak CVP on POD 0 are the risk factors for chylothorax after TCPC operation.

Does routine fenestration improve early and late postoperative outcomes in patients undergoing Fontan palliation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In [patients undergoing Fontan palliation] does [fenestration] affect [early and late postoperative outcomes]?' Altogether 509 papers were found using the reported search, of which 11 papers represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Current data suggest that the use of fenestration has advantages in the immediate postoperative course, with fewer complications such as pleural effusions, shorter hospitalization and decreased early Fontan failure, but comparable long-term outcomes to a non-fenestrated approach. Fenestration should be used in high-risk patients or based on the haemodynamic parameters measured before weaning from cardiopulmonary bypass. Routine use may potentially lead to additional late fenestration closure procedures in some patients, without improving long-term outcomes.

Comparison of pleural effusion between fenestrated and nonfenestrated extracardiac Fontan: A prospective randomized study

BACKGROUND

Fenestration of the baffle/conduit is believed to reduce pleural effusion following the Fontan operation. However, equivocal results have been observed with or without fenestration. This study aims to evaluate the efficacy of fenestration on the amount and duration of pleural effusion following the Fontan operation.

METHODS

About 40 patients undergoing extracardiac Fontan (ECF) were randomized into two groups: one with fenestration (ECF-F; n = 20) or without fenestration (ECF-NF; n = 20). Primary outcome was the amount and duration of pleural effusions. Secondary outcomes were time to removal of the chest tubes, hospital stay, and readmission to the hospital because of recurrent pleural within 30 days of the operation.

RESULTS

Mean age was 11.5 ± 5.07 (range, 8.7-13.5) years in the ECF-F group and 13.6 ± 0.4 years (range, 10.5-15.5) in the (ECF-NF) group. The total drain output was 7.89 mL/kg/d in ECF-NF compared with 6.9 mL/kg/d in the ECF-group (P = .14). Time for removal of pleural tubes was 14.6 ± 0.95 days in the ECF-NF group compared with 11.6 ± days in the ECF-F group. Total duration of hospital stay was higher but not significant in the ECF-NF group compared with the ECF-F group. Two patients in ECF-NF required readmission to the hospital within 30 days following discharge, while there were no readmissions in the ECF-F group.

CONCLUSION

Contrary to the literature, the creation of a fenestration in the ECF circuit was not clearly associated with a reduction in the amount and duration of pleural effusion compared with a non-fenestrated Fontan. These findings may be debatable in high risks versus low risk candidates. However in the present study, in a low risk canditates undergoing the Fontan operation, the daily amount of pleural drainage was no different. Larger studies are needed to confirm these findings.

Alveolar Dead-Space Fraction and Arterial Saturation Predict Postoperative Course in Fontan Patients

OBJECTIVES

Fontan surgery, the final surgical stage in single ventricle palliation, redirects systemic venous blood into the pulmonary circulation for gas exchange. A decrease in pulmonary blood flow can lead to major complications and grave outcomes. Alveolar dead-space fraction represents the portion of inhaled air that does not participate in gas exchange and hence quantifies ventilation-perfusion abnormalities in the lung. Increased alveolar dead-space fraction has been associated with prolonged mechanical ventilation and worse outcome after congenital heart surgery. The association of alveolar dead-space fraction with clinical outcomes in patients undergoing Fontan operation has not been reported.

INTERVENTIONS

None.

DESIGN, SETTING, AND PATIENTS

A retrospective charts review of all pediatric patients who underwent Fontan surgery during June 2010-November 2018 in a tertiary-care pediatric hospital. Associations between alveolar dead-space fraction and arterial oxyhemoglobin saturation to a composite outcome (surgical or catheter-based intervention, extracorporeal membrane oxygenation use, prolonged ventilation, prolonged hospital length of stay, or death) were explored. Secondary endpoints were parameters of severity of illness, chest drainage duration, and length of stay.

MEASUREMENTS AND MAIN RESULTS

Of 128 patients undergoing Fontan operation, 34 met criteria for composite outcome. Alveolar dead-space fraction was significantly higher in the composite (0.33 ± 0.14) versus control (0.25 ± 0.26; p = 0.016) group. Alveolar dead-space fraction greater than or equal to 0.29 indicated a 37% increase in risk to meet composite criteria. Admission arterial oxygen saturation was significantly lower in composite versus control group (93.4% vs 97.1%; p = 0.005). Alveolar dead-space fraction was significantly associated with increased durations of mechanical ventilation, ICU length of stay, duration of thoracic drainage, and parameters of severity of illness.

CONCLUSIONS

Alveolar dead-space fraction and arterial saturation may predict complicated postoperative course in patients undergoing the Fontan operation.

Outcomes of the Non-fenestrated Fontan Procedure at High Altitude

Background:

Although high altitude has been considered a risk factor for the Fontan operation, and an indication for fenestration, there is a paucity of data to support its routine use. Fenestration, with its necessary right to left induced shunt, together with the lower partial pressure of oxygen found with progressive altitude, can significantly decrease hemoglobin oxygen saturation, and therefore, it would be desirable to avoid it.

Objective:

To analyze immediate and medium-term results of the non-fenestrated, extracardiac, Fontan procedure at high altitude.

Methods:

Retrospective analysis of data from consecutive patients who underwent non-fenestrated, extracardiac, Fontan procedure at two institutions located in Mexico City at 2,312 m (7,585 ft) and 2,691 m (8,828 ft) above sea level. High altitude was not considered a risk factor.

Results:

Thirty-nine patients were included, with a mean age of 6.7 years. Mean preoperative indexed pulmonary vascular resistance was 1.7 Wood units. Seventy-nine percent of the patients extubated in the operating room. There was one in-hospital death (2.56%) and one at follow-up. Median chest tube drainage time was 6.5 and 6 days for the right and left pleural spaces. Median oxygen saturation at discharge was 90%. At a median follow-up of six months, all survivors, except one, had good tolerance to daily life activities.

Conclusions:

The present study shows good short- and medium-term results for the non-fenestrated, extracardiac, Fontan operation at altitudes between 2,300 and 2,700 m and might favor this strategy over fenestration to improve postoperative oxygen saturation. Further studies to examine the long-term outcomes of this approach need to be considered.

Comparison of the fenestrated and non-fenestrated Fontan procedures: A meta-analysis

BACKGROUND

The benefits of fenestration for patients undergoing Fontan procedure seem controversial at early and late postoperative stages.

OBJECTIVE

We aimed to compare the outcomes between the fenestrated and non-fenestrated Fontan procedures.

METHODS

Studies comparing the fenestrated and non-fenestrated Fontan procedures were identified by searching the PubMed, EMBASE, and Cochrane Library databases until July 2018. The assessed variables included postoperative oxygen saturation (SaO2), pulmonary artery pressure, mortality, cardiopulmonary bypass (CPB) time, ventilation time, intensive care unit stay, hospital stay, chest tube duration, protein-losing enteropathy, arrhythmia, and other follow-up outcomes including reintervention, stroke/thrombosis, and peak oxygen consumption. A random-effect/fixed-effect model was used to summarize the estimates of the mean difference (MD)/odds ratio (OR) with 95% confidence interval (CI). Subgroup analysis stratified by early and late outcomes was performed.

RESULTS

A total of 1929 Fontan patients from 14 studies were included. The early postoperative SaO2 was lower with fenestration than without fenestration (MD -2.52, 95% CI -4.16 to -0.87, P <.05); however, the late postoperative SaO2 showed no difference between the 2 approaches. The CPB time was shorter without fenestration than with fenestration (MD 10.72, 95% CI 2.54-18.9, P <.05); however, the incidence of arrhythmia was lower with fenestration than without fenestration (OR 0.43, 95% CI 0.25-0.75, P <.05). Other variables showed no significant differences between the 2 approaches in Fontan patients.

CONCLUSION

Fenestration appears to result in a lower incidence of arrhythmia but with a longer CPB time and lower early SaO2. Other outcomes are comparable between the 2 approaches.

Impact of Time Interval Between Glenn and Fontan Procedures on Fontan Operative and Long-Term Follow-up Results

OBJECTIVE

The bidirectional cavopulmonary shunt (BCPS) is an effective palliative procedure which has been widely used to boost outcome of the Fontan procedure. However, there is no standard duration time between these two procedures. Therefore, we investigated whether different time intervals between BCPS and Fontan procedure affects morbidity and mortality of Fontan patients.

METHODS

Between 2004 and 2016, 210 post-BCPS patients underwent Fontan operation at Fuwai Hospital. The median interval between BCPS and Fontan procedure was 3.7 years (range 0.55-11.86 years) and this was used to divide study cohort into Group 1 (< 3.7 years; n = 124) and Group 2 (> 3.7 years; n = 86). We analyzed these patients retrospectively in terms of their preoperative characteristics and post-operative and follow-up results.

RESULTS

Weight z-scores for age at BCPS (- 0.73 ± 1.39 vs - 1.17 ± 1.60, p < 0.05) was significantly higher in Group 2. However, saturation at room air before Fontan (76.42 ± 20.01 vs 82.85 ± 9.69, p < 0.001) was significantly higher in Group 1. The morbidity and mortality were similar between two groups. There were twelve hospital deaths (5.7%): eight (8/124, 6.5%) presented in Group 1 and four (4/86, 4.7%) in Group 2. On multi-variable analysis, risk factors for death were prolonged mechanical ventilation [hazard ratio (HR) 1.02, p = 0.004] and single right ventricle (HR 7.17, p = 0.03). After a mean follow-up of 4.95 years (range 0.74-13.62 years), one patient in Group 1 died of heart failure 13 months after Fontan procedure. The overall Fontan failure in Group 1 was similar to that in Group 2 (2.7% vs 2.6%, p = 0.985). The incidence of arrhythmias and re-intervention were not different between the two groups.

CONCLUSIONS

Fontan procedure could be performed safely in patient who stayed in long duration between Fontan procedure and BCPS without affecting the operative and long-term follow-up results. However, for post-BCPS patients with severe hypoxemia, earlier age at Fontan might be a good choice.

An Early Glenn Operation May be Associated with the Later Occurrence of Protein-Losing Enteropathy in Fontan Patients : Association of Early Glenn and Failing Fontan

Protein-losing enteropathy (PLE) and plastic bronchitis (PB) are major causes of long-term mortality after Fontan operation. The objective of this study was to determine early clinical risk factors before the onset of PLE and PB. In a cohort study, 106 Fontan patients between 2005 and 2013 were examined. A median of 5.3 (1.5-8.5) years later, follow-up questionnaires were used to group the patients in a PLE or PB group (n = 14) and a non-PLE/PB group (n = 92). Prevalence of PLE was 9.4% (n = 10) and of PB 3.8% (n = 4). At follow-up, five patients (4.7%) died of PLE or PB. Median age at death was 6.2 years (IQR 10.5, 95% CI 5.3-23.4). We observed no significant group differences in gender distribution (p = 0.73), ventricular morphology (p = 0.87), surgical technique (p = 0.64), conduit fenestration (p = 0.34), age at Fontan operation (p = 0.54), and need for diuretics (p = 0.56). Hypoplastic left heart syndrome was more frequent in the PLE/PB group 50 vs. 22.8% (p = 0.03) OR 3.4 (95% CI 1.1-10.8). The modified Glenn procedure was performed at a median age of 4 months (IQR 4.0) in the PLE/PB group versus 8 months (IQR 8.0) in the non-PLE/PB group (p = 0.01). The early Glenn procedure and hypoplastic left heart syndrome may be associated with the development of PLE and PB.