Transcatheter fenestration of hemi-Fontan baffles after completion of Fontan physiology using balloon dilatation and stent placement

De novo transcatheter fenestration of hemi-Fontan baffles has not been previously described. The purpose of this report is to present our experience in such de novo transcatheter fenestration in two consecutive patients with absent fenestration in whom the hemi-Fontan baffle was the only direct access to the pulmonary venous atrium. Cathet. Cardiovasc. Diagn. 43:429–432, 1998. © 1998 Wiley-Liss, Inc.     

Pediatric interventions: Emergent stent placement for acute Blalock-Taussig shunt obstruction after stage 1 Norwood surgery

A neonate underwent a stage 1 Norwood surgery for hypoplastic left heart syndrome and subsequently developed profound cyanosis and hemodynamic instability. Catheterization revealed an occluded modified Blalock-Taussig shunt. Angioplasty and stent implantation resulted in immediate angiographic and clinical improvement, which has persisted at 5-month follow-up. This therapy may provide lifesaving treatment in selected patients. Cathet. Cardiovasc. Diagn. 42:191–194, 1997. © 1997 Wiley-Liss, Inc.     

A 20-Year Follow-up after the Fontan Operation in a Population with Hypoplastic Left Heart Syndrome

Background: Thromboembolic events are a cause of significant morbidity and mortality in the Fontan population. We previously reported on coagulation profile changes in a cohort of patients with hypoplastic left heart syndrome (HLHS) from Stage I through Fontan completion. In this report, we examine their clinical status, anticoagulation and incidence of thromboembolic events up to 20 years post Fontan. Methods: A retrospective chart review was conducted for twenty (20) surviving patients, from 1998 through December 2020. Patients who underwent orthotopic heart transplantation (OTx) were followed until their transplant. Patients who were found in the original study to have a factor VIII activity level >160%, were examined separately. Results: Most patients had follow-up within the last two years (2018–2020). Two patients underwent OTx and two patients died. Anticoagulation strategy was variable. Most patients were on aspirin monotherapy. There was a total of twelve thrombotic events (63.2%). These included six cerebrovascular accidents (two of which were fatal). Three out of the seven patients with elevated factor VIII activity from the original study had thromboembolic events (42.9%). Fontan complications were variable. Some degree of Fontan Associated Liver Disease was universal. Conclusions: This retrospective review of a group of single-ventricle patients post Fontan, illustrates the variability in anticoagulation therapy that exists in this population. A large proportion of patients suffered a significant thromboembolic event, including the patients with elevated factor VIII. Further investigation into the patients with elevated factor VIII may help determine whether a different antithrombotic strategy post Fontan would be beneficial.     

Novel technique to reduce the size of a Fontan Diabolo stent fenestration

Objectives : To develop an effective catheter technique to reduce the size of a Diabolo stent fenestration in the failing Fontan circulation. Background : Diabolo stent fenestration is employed by many centers in the treatment of the failing Fontan patient. With subsequent recovery, exercise tolerance may be impaired by significant desaturation secondary to the right to left shunt across the fenestration. Complete fenestration closure carries the risk of recurrence of the initial symptoms and, hence, reduction of the size of fenestration should be the preferred technique. Methods : Twenty‐eight patients with failing Fontan circulations (16 early and 12 late) underwent Diabolo stent fenestration for relief of symptoms. Five of these patients remained very limited by severe desaturation even at rest, after complete recovery from symptoms. Further cardiac catheterization with crimping/reduction of the size of the waist of the stent was carried out using a technique whereby a snare catheter was placed over the waist of the stent aided by an arterio‐venous guidewire loop and a balloon catheter placed within the stent. Results : All 5 patients had successful stent reduction with improvement in saturations, whilst still maintaining a small residual fenestration. No complications were encountered. Conclusion : This novel technique of reduction of a diabolo stent fenestration, in a failing Fontan circulation, offers the advantages of avoidance of implanting further devices in the circulation and the ability to redilate the stent should symptoms recur. © 2010 Wiley‐Liss, Inc.     

Stage one Norwood procedure results: the green lane experience

Aims: This study examined the presentation outcome, morbidity and mortality of infants who have undergone the stage one Norwood procedure for single ventricle reconstruction.

Methods: A retrospective review was done on the first 20 patients to undergo this procedure at Green Lane Hospital, Auckland, New Zealand. Seven patients were diagnosed antenatally. Fetal cardiology records in the same time period were reviewed.

Results: Twelve of the 20 patients (60%) have survived, and all of these patients have undergone their bi-directional Glenn procedure with no mortality. Eight patients died, with five of the deaths occurring in the perioperative period. Initial surgical mortality was 75%, decreasing to 25% since 1998. Antenatal diagnosis has not improved surgical outcome to date.

Conclusion: With advances in surgical technique and pre- and postoperative care, neonates born with single ventricle anatomy have an acceptable surgical option. Babies who survive the Norwood operation have a good chance of surviving the later stages of the cardiac reconstruction process, and they have a reasonable outlook in the intermediate term.     

Late fenestration of the extracardiac conduit in a Fontan circuit by sequential stent flaring.

Recent Fontan circuits frequently involve an extracardiac conduit. We report on a new technique to create a late fenestration in such an extracardiac circuit by sequential flaring of a stent in the fenestration.     

Surveillance for liver complications after the Fontan procedure

The physiological consequences of the Fontan circulation impose risk for hepatic dysfunction and may culminate in hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Consensus regarding appropriate surveillance modalities to diagnose liver disease in Fontan patients is lacking, in part due to the relative lack of strong evidence and prospective studies in this patient population. The goal of this paper is to critically review the current evidence and provide recommendations for the surveillance of hepatic complications in the post‐Fontan patient population.     

The Fontan procedure in adults

SETTING—Tertiary adult congenital cardiac referral centre.
DESIGN—Retrospective cross sectional analysis.
OBJECTIVES—To report our 20 year experience with adult Fontan operations, and to compare late outcome in patients with single ventricle with definitive aortopulmonary or cavopulmonary shunt palliation.
PATIENTS AND MAIN OUTCOME MEASURES—Patients older than 18 years undergoing Fontan operation between 1 January 1982 and 31 December 1998 were identified. Mortality and late outcome were derived from hospital records. These patients were compared with a cohort of 50 adults with single ventricle who had not undergone a Fontan operation.
RESULTS—61 adults, median age 36 years (range 18-47 years), with a median follow up of 10 years (range 0-21 years) were identified. Actuarial survival was 80% at one year, 76% at five years, 72% at 10 years, and 67% at 15 years. Compared with before the Fontan operation, more patients were in New York Heart Association (NYHA) functional class I or II at the latest follow up (80% v 58%, p < 0.001). Systolic ventricular function deteriorated during follow up such that 34% had moderate to severe ventricular dysfunction at the latest follow up compared with 5% before Fontan (p < 0.001). Arrhythmia increased with time (10% before Fontan v 57% after 10 years, p < 0.001). Fontan patients had improved NYHA functional class, ventricular function, atrioventricular regurgitation, and fewer arrhythmias than the non-Fontan group at the latest follow up.
CONCLUSION—The Fontan operation in adults has acceptable early and late mortality. Functional class, systolic ventricular function, atrioventricular regurgitation, and arrhythmia deteriorate late after surgery but to a lesser degree than in non-Fontan patients with a single ventricle.


     

Percutaneous transcatheter communication between the pulmonary artery and atrium following an extra‐cardiac Fontan

In a nonfenestrated modified Fontan, transcatheter creation of a fenestration presents technical difficulties, especially with the extra‐cardiac modification where a Gore‐Tex tube is placed between the inferior caval vein and the pulmonary arteries. The authors describe an alternative approach to perforating the Gore‐Tex tube to create a fenestration by making a communication between the pulmonary artery and the atrial chamber, thus bridging the two circulations through native tissue. © 2008 Wiley‐Liss, Inc.     

Stent implantation for aortic coarctation complicating the Norwood operation in a 48-day-old baby.

A female infant developed severe aortic coarctation 42 days after a Norwood operation. Balloon dilatation was ineffective due to rapid recoil of the narrowing, but stent implantation completely abolished coarctation. Although the patient died because of low systemic output with high pulmonary flow 62 days after stent implantation, an autopsy showed that the implanted stent was widely patent without any restenosis. Transcatheter stent implantation should be considered for coarctation in selected situations even in early infancy.     

Superior vena cava thrombectomy with the X-SIZER catheter system in a child with Fontan palliation.

A 4-year-old female with hypoplastic left heart syndrome and Fontan palliation presented with severe neurologic impairment from thrombosis of the superior vena cava (SVC). She underwent successful SVC thrombectomy with the X-SIZER Thrombectomy Catheter System, followed by balloon angioplasty. She demonstrated rapid improvement in her neurologic deficits after the procedure. This represents the first published use of the X-SIZER in a child and its first published use for SVC thrombectomy.     

Potential goals for the dimensions of the pulmonary arteries and aorta with stenting after the Fontan operation.

The purpose of this study was to clarify desired stent sizes for stenotic lesions in the post-Fontan circulation. Using angiograms from 22 patients before and at late follow-up (> or = 15 years) after the Fontan operation, we measured the maximum diameters of the proximal pulmonary arteries (PA) and the descending aorta. The diameters of the PA ipsilateral to the inferior vena cava, contralateral to the inferior vena cava, and descending aorta after the Fontan were 10.6-22.6 (15.8 +/- 3.3), 8.0-19.1 (12.9 +/- 3.1), and 12.1-18.9 (15.8 +/- 2.0) mm, respectively, while the percent of normal predicted diameters (% N) were 55%-104% (70% +/- 14%), 38%-99% (66% +/- 17%), and 46%-74% (60% +/- 7%), respectively. Despite somatic growth, the % N of all vessel diameters decreased significantly after the Fontan operation. In conclusion, smaller-sized stents should be acceptable for both the pulmonary artery and descending aorta in the Fontan circulation.     

Serial assessment of left ventricular diastolic function after Fontan procedure

OBJECTIVE—To assess longitudinal changes in systemic ventricular diastolic function late after the Fontan procedure.
DESIGN AND PATIENTS—Prospective study of 13 patients at 2.8 (2.0) years (early) and again at 11.4 (2.0) years (late) after the Fontan procedure by Doppler echocardiography with simultaneous ECG, phonocardiogram, and respirometer.
SETTING—Tertiary paediatric cardiac centre.
RESULTS—The isovolumic relaxation time (IVRT) was significantly longer, and E wave deceleration time, E and A wave velocities, and E:A velocity ratio were reduced compared to normal both early and late after the procedure. The mean (SD) z score of IVRT decreased significantly from +2.50 (1.00) to +1.24 (0.80) (p = 0.002), and the z score of the E wave deceleration time decreased from −1.69 (1.31) to −2.40 (1.47) (p = 0.03) during follow up. The A wave deceleration time also tended to decrease (early 80 (12) ms v late 73 (11) ms, p = 0.13) with increased follow up. There were no changes of the E and A wave velocities and E:A velocity ratio. The E wave velocity was inversely related to IVRT both early (r = −0.82, p = 0.001) and late (r = −0.59, p = 0.034) after the operation. The prevalence of diastolic flow during isovolumic relaxation decreased from 85% (11/13) to 38% (5/13) (p = 0.04), while that of mid diastolic flow increased from 23% (3/13) to 77% (10/13) (p = 0.02) between the two assessments.
CONCLUSIONS—Left ventricular diastolic function remains highly abnormal late after the Fontan procedure. The longitudinal changes demonstrated on follow up are compatible with reduction of left ventricular compliance in addition to persisting abnormalities of relaxation.


Keywords: diastolic function; Fontan procedure     

Exercise Capacity Improves after Transcatheter Closure of the Fontan Fenestration in Children

Objectives. This study evaluated the aerobic capacity, exercise capacity, and arterial oxygen saturation (O₂Sat) in children before and after transcatheter Fontan fenestration closure. Design. Observational study comparing exercise parameters and hemodynamics before and after transcatheter fenestration closure in Fontan patients. Outcome Measures. Working capacity, exercise duration, oxygen consumption (VO₂), and arterial O₂Sat were evaluated during aerobic exercise. Results. Twenty patients (mean age 11.4 years) underwent standardized exercise testing before and after fenestration closure. Twelve patients underwent cycle ergometry testing (mean age 14.8 years) (group1), and eight younger patients (mean age 6.4 years) underwent Bruce treadmill testing (group 2). The same exercise protocol was used in each patient before and after fenestration closure (interval between tests: 118 ± 142 days). Immediately following fenestration closure at cardiac catheterization, cardiac index decreased (3.0 to 2.1 L/minute/m²) and Fontan pressure increased (11 ± 2 to 12 ± 2 mm Hg) with an increased arterial saturation (92 to 96%) (P < .001). The total group demonstrated no significant change in pre‐ and postclosure maximal heart rates (164 ± 21 and 169 ± 19 bpm). Rest and exercise O₂Sat increased (89 and 82 to 95 and 92%) (P < .0001). Exercise duration increased (7.7 ± 1.9 to 9.2 ± 2.4 minutes) (P < .0005). Maximal VO₂, indexed maximal VO₂, and total working capacity in kilopond‐meters (kpm) increased (1.2 ± 0.5, 27 ± 7 and 2466 ± 1012 to 1.3 ± 0.4 L/minute, 31 ± 9 mL/kg/minute and 2869 ± 1051 kpm, respectively) (P < .005). Conclusion. In children with a univentricular heart after Fontan palliation, transcatheter fenestration closure improves exercise arterial O₂Sat and aerobic capacity despite a restricted resting cardiac output documented by catheterization immediately after the closure procedure.