Long-Term Effects of Percutaneous Fenestration Following the Fontan Procedure in Adult Patients with Congenital Univentricular Heart

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

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.

Computed Tomography in the Evaluation of Fontan Circulation

The Fontan procedure is a well-established surgical technique to improve survival in patients with univentricular heart disease. The procedure reroutes the systemic venous flow to the lungs, bypassing the right ventricle. The originally proposed method involved direct anastomosis of the right atrium to the pulmonary artery. Since then, several modifications have been made in the original technique leading to the modern Fontan, or total cavopulmonary connection. The modern Fontan technique has shown improved surgical outcomes and increased life expectancy in patients with univentricular disease. Due to the increased survival of these patients, long-term complications are becoming more prevalent. Common complications of Fontan procedure include right atrial dilatation and thrombosis; conduit stenosis and thrombosis; right-to-left and left-to-right shunts; hepatic congestion and cirrhosis; and lymphovascular. Computed tomography (CT) can reliably depict the normal Fontan anatomy and various postoperative complications. A fundamental understanding of the techniques of CT, including imaging protocols and common interpretive pitfalls, allows targeted imaging and precise reporting of clinically significant findings. Radiologists should be familiar with the multiple stages of single-ventricle palliation, normal Fontan anatomy, pathophysiology, and imaging features of common Fontan-related complications.

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 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.

Long Term Consequences of the Fontan Procedure and How to Manage Them

In 1971, Fontan and Baudet described a surgical technique for successful palliation of patients with tricuspid atresia. Subsequently, this technique has been applied to treat most forms of functional single ventricles and has become the current standard of care for long-term palliation of all patients with single ventricle congenital heart disease. Since 1971, the Fontan procedure has undergone several variations. These patients require lifelong management including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function along with multi organ evaluation. As these patients enter middle age, there is increasing awareness regarding the long-term complications and mortality. This review highlights the long-term outcomes of the Fontan procedure and management of late sequelae.