Creation Of Fenestration Research Articles

Fontan-type procedures: residual lesions and late interventions

Background. The purpose of this study was to determine the type and incidence of hemodynamic and electrophysiological abnormalities requiring surgical or catheter-based interventions in a single-center long-term experience. Methods. Eighty-eight patients with a follow-up of at least 5 years (mean follow-up, 9.6 ± 2.6 years) after Fontan-type procedures were included. All patients had undergone cardiac catheterization either as part of the regular postoperative protocol or because of symptomatic atrial tachycardia or increasing cyanosis. Results. Freedom from reoperation for up to 5 years was documented for 82% of patients and decreased to 76% after 8 years. Late reoperations included conversion of an atriopulmonary anastomosis to a total cavopulmonary anastomosis in 2 patients with atrial dysrhythmia and implantation of an extracardiac conduit in 1 patient with left atrial isomerism and intrapulmonary arteriovenous malformations after a Kawashima operation. Decline in sinus node function with symptomatic bradycardia required pacemaker therapy in 10 patients (11%). Transcatheter interventions included fenestration occlusion in 5 of the 11 patients with initial baffle fenestration. In 6 of 17 patients with aortopulmonary collaterals, coil occlusion was indicated to reduce future systemic ventricular volume load. Various systemic venous collaterals were documented in 11 patients and required coil occlusion in 2. One patient with symptomatic protein-losing enteropathy underwent transcatheter fenestration creation without sustained relief of symptoms. Freedom from transcatheter interventions decreased from 94% to 82% after 5 and 10 years, respectively. Conclusions. During long-term follow-up, reoperations are rare and mainly involve Fontan conversion to either a lateral-tunnel or extracardiac-conduit procedure. Detailed angiographic evaluation on a routine basis allows identification of the vascular sites of origin of aortopulmonary collateral vessels and systemic venous collaterals potentially developing during long-term follow-up. Transcatheter interventions including fenestration occlusion and occlusion of venous collaterals and aortopulmonary collaterals were performed to maintain and improve the Fontan circulation in clinically symptomatic and asymptomatic patients. During long-term follow-up after Fontan-type operations, a regular postoperative cardiac catheterization protocol is recommended.

Strategies to treat protein-losing enteropathy

Protein-losing enteropathy (PLE), excessive serum protein loss within the gastrointestinal tract, after Fontan operation is a poorly understood disorder. Reported to occur anywhere from weeks to years after Fontan operation, there are no identifiable risk factors for its development, and its clinical manifestations vary widely from significant morbidity and mortality to mild-to-moderate hypoproteinemia with minimal functional impairment. Treatment strategies, tailored to the severity of the disease, include symptomatic relief with diuretics and supplemental protein, attempts at halting intestinal protein leak using steroids or heparin, and alteration of cardiovascular physiology via fenestration creation, atrial pacing, or heart transplantation. A better understanding of the pathophysiology of PLE will allow the development of more effective treatment modalities. We hypothesize an abnormality of local intestinal circulation in patients with PLE that may be related to low cardiac output. Compensatory flow redistribution takes place under conditions of low cardiac output. We studied superior mesenteric artery flow using Doppler ultrasound in 40 patients after Fontan operation, 13 of whom had clinical signs of PLE, and compared them with 25 normal control patients. Diastolic velocities were lower in Fontan subjects, and the ratio of systolic-to-diastolic velocities and the resistance index were higher in Fontan patients compared with the control group. Patients with PLE after Fontan operation had higher systolic-to-diastolic velocities and resistance index than patients with Fontan and no active PLE. However, subjects with Fontan circulation but without PLE had higher indices of mesenteric resistance than the normal controls, suggesting an abnormality of the mesenteric circulation even in those without overt signs of PLE. It is plausible to postulate that activation of the renin-angiotensin system with increased levels of circulating angiotensin II may be responsible for the increase in mesenteric vascular resistance seen after Fontan operation, thereby placing these patients at risk for development of PLE. Copyright © 2002 by W.B. Saunders Company

Atrial pacing: An alternative treatment for protein-losing enteropathy after the Fontan operation

J Thorac Cardiovasc Surg 2001;121:582-3

Late surgical fenestration for complications after the Fontan operation.

Significant morbidity after Fontan operation results in either takedown, heart transplantation, or death. Initial creation of a fenestration results in less morbidity and mortality; however, the role of late creation of a fenestration in aiding patients manifesting morbidity after an initial nonfenestrated Fontan operation is unclear. We reviewed our experience with late creation of a surgical fenestration in 9 patients (5.2 +/- 3.1 years old) exhibiting chronic effusions (n = 4) or protein-losing enteropathy (PLE) (n = 5) after lateral tunnel-type Fontan operation. Patients with effusions had creation via coronary punch of two or three 3-mm defects; patients with PLE had creation of a large, 5-mm defect. One child with effusions and multisystem organ failure before fenestration died 7 weeks after surgery secondary to low cardiac output; the other 3 had resolution of effusions within 4 to 6 weeks. Of the 5 with PLE, 3 had normalization of serum proteins and resolution of symptoms at 2 to 6 weeks. The 2 failures had arterial saturations > 89% after surgery. Follow-up was from 25 to 30 months. Spontaneous closure of defects occurred in all 3 with effusions. No return of symptoms was noted in 2; however, the third reaccumulated effusions and has undergone refenestration with a large defect. All 3 patients with PLE have remained asymptomatic with patency of the fenestration (4 to 5 mm on echocardiography) and arterial saturation < or = 85% for > 2 years. Late surgical creation of fenestration results in resolution of morbidity after Fontan operation. Improvement is related to the degree of right-to-left shunt created.

Transcatheter Fenestration Dilation and/or Creation in Postoperative Fontan Patients

There are very few therapeutic options for severely symptomatic Fontan patients after spontaneous complete or virtual fenestration closure. Its reopening in 14 such patients led to dramatic hemodynamic improvement in most. The clinical experience with transcatheter fenestration creation and/or dilation in symptomatic Fontan patients is reported demonstrating feasibility, safety, and a novel management option for these patients.

Fontan operation: Influence of modifications on morbidity and mortality

The mortality rate of the Fontan operation for heart malformations with a single or dominant ventricle has been reduced by dividing the procedure into two stages. The hemi-Fontan procedure allows early reduction of the volume work of the single ventricle and remodeling of ventricular geometry before a completion Fontan operation. Despite the improvement of survival with this strategy (8% mortality for completion Fontan versus 16% mortality for primary Fontan operation), morbidity related to serous effusions remains substantial. Further technical modifications have been undertaken in an effort to reduce morbidity and further reduce mortality. From January 1990 through June 1993, 200 patients underwent completion Fontan procedures after previous hemi-Fontan operations. Mean age was 23 months, and 157 patients were less than 24 months of age. Diagnoses were hypoplastic left heart syndrome (127 patients), tricuspid atresia (19 patients), single left ventricle (17 patients), complex double-outlet right ventricle (16 patients), pulmonary atresia with intact ventricular septum (8 patients), and other (13 patients). Overall, early mortality rate was 8% (16 patients). In the last 112 patients, the procedure was modified technically by creating one or more fenestrations in the baffle used to separate systemic venous blood from pulmonary venous blood (36 patients), or by excluding one or more hepatic veins from the systemic venous pathway (76 patients). Early mortality for these 112 patients was reduced to 4.5% (5 patients). Substantial morbidity from serous effusions occurred at a rate of 45% (35 of 78 patients) among survivors who had received neither technical modification. Among survivors of a fenestrated Fontan procedure, the incidence of effusions was 39% (14 of 36 patients). Among survivors of a completion Fontan operation with partial exclusion of the hepatic veins, the incidence was only 14% (10 of 71 patients). We conclude that the mortality and morbidity rates of a completion Fontan procedure have been reduced further by either creation of fenestrations in the atrial baffle or association of one or more hepatic veins with the pulmonary venous atrium. The latter modification has significantly reduced the incidence of serous effusions.