Fenestration in extracardiac conduits in children after modified Fontan operation by implantation of stent grafts

A computational study of the Fontan circulation with fenestration or hepatic vein exclusion

Fontan patients may undergo additional surgical modifications to mitigate complications like protein-losing enteropathy, liver cirrhosis, and other issues in their splanchnic circulation. Recent case reports show promise for several types of modifications, but the subtle effects of these surgeries on the circulation are not well understood. In this paper, we employ mathematical modeling of blood flow to systematically quantify the impact of these surgical changes on extracardiac Fontan hemodynamics. We investigate two modifications: (1) the fenestrated Fontan and (2) the Fontan with hepatic vein exclusion. Closed-loop hemodynamic models are used, which consist of one-dimensional networks for the major vessels and zero-dimensional models for the heart and organ beds. Numerical results suggest the hepatic vein exclusion has the greatest overall impact on the hemodynamics, followed by the largest sized fenestration. In particular, the hepatic vein exclusion drastically lowers portal venous pressure while the fenestration decreases pulmonary artery pressure. Both modifications increase flow to the intestines, a finding consistent with their utility in clinical practice for combating complications in the splanchnic circulation.

Fenestration closure with Amplatzer Duct Occluder II in patients after total cavo-pulmonary connection

INTRODUCTION

Creation of a fenestration during completion of a total cavopulmonary connection (TCPC) has been associated with a reduction in early mortality and morbidity. However, the long-term benefits are negated by an associated limitation in exercise tolerance and the potential risks of thrombo-embolic complications. We sought to describe the safety and efficacy of an Amplatzer Duct Occluder II (ADO II) for transcatheter fenestration closure following TCPC.

MATERIAL AND METHODS

Between January 2000 and July 2014, 102 patients underwent percutaneous closure of extra-cardiac TCPC fenestrations with a range of devices. Patients in whom fenestration closure was performed with an ADO II and who had at least 6 months of follow-up were included in this study.

RESULTS

Forty-seven patients had successful fenestration occlusion with an ADO II. The mean oxygen saturation and mean systemic venous pressures increased from 84.8 ±6.1% before to 97.6 ±2.9% (p < 0.001) after and from 14.2 ±2.15 mm Hg before to 15.6 ±2.2 mm Hg after closure (p < 0.001). Eight patients developed heart failure symptoms, managed by optimization of medical therapy, with 1 patient requiring device removal to reopen the fenestration. Color Doppler transthoracic echocardiography demonstrated residual flow across the device in 18 (38%), 10 (22%), 5 (11%) and 4 (9%) patients before discharge, at 1 and 6 months, and at the latest outpatient visit, respectively.

CONCLUSIONS

The ADO II can be safely and effectively used to close fenestrations in extra-cardiac type Fontan completions. Many of the design features of this device confer potential benefit in this population.

Unusual method of creation of a transcatheter fenestration in an extracardiac conduit Fontan circulation

Failing Fontan physiology in univentricular hearts manifest with protein-losing enteropathy, plastic bronchitis, low cardiac output, and recurrent effusions. Transcatheter creation of fenestration in a failing Fontan may be useful in alleviating the symptoms by improving the cardiac output. It is traditionally achieved by puncturing through the conduit from femoral or jugular venous access. In the absence of good venous path, transhepatic access provides a direct route for needle puncture of the conduit. If marked intimal ingrowth into the conduit results in increasing rigidity and makes the conduit nonyielding, alternative approaches may be needed. A successful creation of pulmonary artery to atrial roof communication through the potential space of transverse sinus using a covered stent is presented.

Fifteen-year single center experience with the "Giessen Hybrid" approach for hypoplastic left heart and variants: current strategies and outcomes

Presented is a retrospective outcome study of a 15-year single institutional experience with a contemporary cohort of patients with hypoplastic left heart syndrome and complex that underwent a "Giessen Hybrid" stage I as initial palliation. Hybrid approach consisting of surgical bilateral pulmonary artery banding and percutaneous duct stenting with or without atrial septum manipulation was developed from a rescue approach to a first-line procedure. Comprehensive Aristotle score defined pre-operative condition. Fifteen-year follow-up mortality is reported as occurring within the staged univentricular palliation or before and after biventricular repair. Hybrid stage I was performed in 154 patients; 107 should be treated by single ventricle palliation, 33 by biventricular repair (BVR), 7 received heart transplantation, and 7 were treated by comfort care, respectively. Overall 34 children died. The Aristotle score (mean value 18.2 ± 3) classified for univentricular circulations in newborns did not have statistical impact on the outcome. Two patients died during stage I (1.2%), and the interstage I mortality was 6.7%, and stage II mortality 9%, respectively. Stage III was up to now performed in 57 patients without mortality. At 1 year, the overall unadjusted survival of HLHS and variants was 84% and following BVR 89%, respectively. The Fifteen-year survival rate for HLHS and variants was 77%, with no significant impact of birth weight of less than 2.5 kg. In conclusion, Hybrid stage I fulfilled the criteria of life-saving approach. In our institution, Hybrid procedure replaced Norwood-staged palliation with a considerable mid- and long-term survival rate. Considering interstage mortality close surveillance is mandatory.

The role of stents in the treatment of congenital heart disease: Current status and future perspectives

Intravascular or intracardiac stenoses occur in many forms of congenital heart disease (CHD). Therefore, the implantation of stents has become an accepted interventional procedure for stenotic lesions in pediatric cardiology. Furthermore, stents are know to be used to exclude vessel aneurysm or to ensure patency of existing or newly created intracardiac communications. With the further refinement of the first generation of devices, a variety of "modern" stents with different design characteristics have evolved. Despite the tremendous technical improvement over the last 20 years, the "ideal stent" has not yet been developed. Therefore, the pediatric interventionalist has to decide which stent is suitable for each lesion. On this basis, currently available stents are discussed in regard to their advantages and disadvantages for common application in CHD. New concepts and designs developed to overcome some of the existing problems, like the failure of adaptation to somatic growth, are presented. Thus, in the future, biodegradable or growth stents might replace the currently used generation of stents. This might truly lead to widening indications for the use of stents in the treatment of CHD.

Results of transcatheter Fontan fenestration to treat protein losing enteropathy

Transcatheter fenestration to create an interatrial communication has been used to treat patients with protein losing enteropathy (PLE) after Fontan operation. No systematic data have been reported assessing the results of this procedure. Our institutional database was queried to identify patients after Fontan operation who had transcatheter fenestration to treat PLE. Clinical notes, laboratory data, echocardiograms, and cardiac catheterization data were reviewed. From 1995 to 2005, 16 transcatheter fenestration procedures were performed in seven patients. Median age at fenestration was 18 years (range 13-41 years). Median duration of follow-up was 3.6 years (range 0.2-10.4 years). Techniques for fenestration included blade/balloon septostomy, stent placement, Amplatzer-fenestrated ASD device, and balloon dilation of previous stent. Size of the fenestration created was 5.2 +/- 1.1 mm. Systemic venous pressure remained unchanged after fenestration. Cardiac index increased significantly. Reduction of ascites and edema was noted after 9 of the 16 procedures. Ten of 16 (63%) of fenestrations spontaneously occluded. Three patients are free of ascites although recurrence of PLE occurred in all. One patient with a patent fenestration continues to have ascites. Two patients had Fontan takedown. One patient had conversion to a fenestrated extracardiac conduit Fontan and died postoperatively. The results of transcatheter Fontan fenestration are often disappointing. Maintaining fenestration patency is difficult. Even after "successful" fenestration, resolution of PLE may be incomplete and recurrences have occurred in all. Early consideration should be given to Fontan takedown or cardiac transplant in severely symptomatic patients with PLE who do not respond to fenestration. Transcatheter fenestration may be a bridge to a definitive procedure.