The role of the Glenn shunt in patients undergoing the Fontan operation

Twenty-seven patients (3 to 22 years) underwent the Fontan operation. Seventeen had tricuspid atresia and 10 had other complex lesions. Sixteen patients had a Glenn shunt (12 prior to, three simultaneous with, and one following the Fontan operation). One early death (3.7%) occurred in a 4 1/2-year-old child with tricuspid atresia II-C, previous pulmonary artery banding, and a closing ventricular septal defect (80 mm Hg gradient). There were two late deaths (7.4%) from Candida sepsis, after 4 and 6 months, respectively. The 24 patients who survived the Fontan operation had postoperative hospital stays of 6 to 90 days (average 18). Patients with tricuspid atresia and an established Glenn shunt (nine patients, Group I) had postoperative hospital stays of 7 to 19 days (average 9.5), and none had significant pleural or pericardial effusions. Patients with tricuspid atresia without a Glenn shunt (seven patients, Group II) had postoperative hospital stays of 6 to 60 days (average 17.5), with three having significant effusions. Of the patients with other complex lesions, all without an established Glenn shunt, five had significant effusions. Four additional major complications (two tricuspid patch disruptions with ineffective pulmonary blood flow and two complete occlusions of a valved conduit) were encountered in which the Glenn shunt proved lifesaving. We believe that an established Glenn shunt played a major role in attaining minimal postoperative hemodynamic instability, effusions, renal failure, and mortality in our patients. The Glenn shunt should be considered in patients who are less than ideal candidates for the Fontan operation.     

Thrombosis of intracardiac or extracardiac conduits after modified Fontan operation in patients with azygous continuation of the inferior vena cava.

BACKGROUND: The Fontan procedure in patients with azygous continuation of the inferior vena cava, requires a cavo-pulmonary anastomosis, and deviation of the hepatic venous drainage to the pulmonary arteries using an intra- or extracardiac conduit. METHODS: We report thrombosis of two pericardial conduits and one Gore-Tex (W. L. Gore & Assoc, Flagstaff, AZ) graft used for deviation of hepatic venous blood to the pulmonary arterial tree in 3 patients aged 11, 24, and 28 years. Two of the conduits (pericardial) were intraatrial. The Gore-Tex graft was placed in an extracardiac position. The two pericardial conduits obstructed completely. RESULTS: One patient died at reoperation. In the 2nd patient, the conduit was excised and the hepatic veins were allowed to drain into the atrium. In the 3rd patient, partial thrombosis of the Gore-Tex conduit was noted 30 months after operation. The thrombus resolved with oral anticoagulation. CONCLUSIONS: Conduits carrying only hepatic venous blood flow may have a higher risk of thrombosis. Anticoagulation or alternative methods of directing hepatic blood flow to the pulmonary circulation must be considered in these patients.     

Surgical management of the occluded carotid artery

Of 36 patients with symptomatic total occlusion of the common carotid and/or internal carotid arteries, ipsilateral operation was performed in 20. Twenty-eight patients had occlusion of the internal carotid artery, four of the common carotid alone, and four had occlusion of both vessels. Thirteen patients had completed stroke. Noninvasive examination erroneously suggested internal carotid patency in three patients. Of six patients with occluded common carotid arteries, two underwent thromboendarterectomy, two underwent saphenous vein bypass, and two underwent Dacron graft bypass procedures. Five patients underwent attempted internal carotid thromboendarterectomy and three patients underwent external carotid endarterectomy. Seven patients underwent primary temporal to middle cerebral bypass procedures. There were no perioperative deaths and no patients had permanent neurologic deterioration. There were two postoperative complications. At follow-up 1 to 43 months after operation, five of six patients who had undergone common carotid revascularization had improved neurologically while other treatment groups had no definite improvement. Revascularization of an occluded common carotid artery is a safe procedure that successfully alleviates symptoms of cerebral ischemia. Internal carotid disobliteration and external carotid endarterectomy alone provide limited neurovascular benefit. Benefits of extracranial-to-intracranial bypass were not apparent from this small series.     

Thromboembolic problems after the Fontan operation

One of the major causes of morbidity and mortality after the Fontan operation is thromboembolic events (TE). To assess the current knowledge of TE after Fontan surgery, a comprehensive MEDLINE search of the English literature from 1971 to 2000 was conducted using the key words Fontan, univentricular heart, children, thrombosis, congenital heart disease, cavopulmonary, and palliation. Other relevant publications were identified from bibliographies of the literature retrieved. Fifty-one studies were identified and analyzed for incidence, potential morbidity and mortality, risk factors, prophylactic options, and risk/benefit ratio of prophylactic anticoagulation as relates to TE after Fontan surgery. There were 23 case reports, 13 retrospective cohort studies that included some details about TE among other reported outcomes after Fontan procedures, eight retrospective cohort studies in which TE was the primary outcome measure, and seven articles reporting cross-sectional point surveys, only three of which directly surveyed TE as an outcome. Based on an analysis of the current literature, there is insufficient evidence to make clear recommendations about optimal anticoagulant prophylaxis at this time. Multicenter randomized controlled trials comparing prophylactic antiplatelet with anticoagulation therapies are needed to provide rational scientific guidelines for future management of Fontan patients. Copyright © 2002 by W.B. Saunders Company     

Atrial thrombi after the Fontan operation

This report documents four instances of right atrial thrombi discovered from four days to five years after Fontan-type operations. Two of the thrombi were removed at reoperation, and two diminished in size during anticoagulation therapy. There were no pulmonary emboli in this small series, but the ominous implications of right atrial thrombi in the post-Fontan situation are obvious. For this reason we recommend regular echocardiographic surveillance of all patients who have had the Fontan operation and anticoagulation in certain situations.     

Thrombus formation after the Fontan operation

Background. Thrombus formation is common after a Fontan operation. We investigated the frequency and location of thrombus in our population of children based on the type of Fontan operation performed.

Methods and Results. Between January 1987 and January 1999, 592 patients underwent echocardiography after Fontan operation and 52 (8.8%) had intracardiac thrombus. Median age at Fontan operation was 1.9 years (range 0.8 to 35.1). Freedom from thrombus was 92%, 90%, 84% and 82% at 1, 3, 8, and 10 years after Fontan operation, respectively. There was no difference in freedom from thrombus, based on type of operation (atriopulmonary vs. lateral tunnel) or presence of fenestration. Thrombus was detected in the systemic venous atrium in 26 (48%), in the pulmonary venous atrium in 22 (44%), in both atria in 1 (2%), in the hypoplastic left ventricular cavity in 2 (8%), and in the ligated pulmonary artery stump in 1 (2%).

Conclusions. Thrombus formation occurs with equal frequency in all types of modifications and is seen in the pulmonary, as well as the systemic venous atria. Our study suggests that thrombus formation is inherent to the physiology after Fontan operation and is not related to the type of modification performed.     

Diastolic asynchrony and myocardial dysfunction in patients with univentricular heart after Fontan operation

Background

We aimed to assess the existence of myocardial dysfunction and intra-univentricular diastolic asynchrony in patients after Fontan operation.

Methods

Twenty patients after Fontan procedure and 30 age-matched controls were included in the study. The global function of the univentricular heart was analyzed by the Tei index. Regional myocardial velocities and strain of the univentricular heart including the rudimentary right ventricle (RV) were quantified by tissue Doppler imaging. Intra-univentricular or intra left ventricular (LV) diastolic delay was measured from the difference of diastolic intervals (time to peak early diastolic velocity), measured at LV lateral wall and the rudimental RV wall in patients, or LV lateral wall and the ventricular septum in controls.

Results

Compared to the control group, patients after Fontan operation had significantly elevated Tei index (0.24 ± 0.02 vs. 0.41 ± 0.1, p < 0.001). On the other hand, the regional myocardial velocities and strains of the univentricular heart including the rudimentary RV were significantly reduced (p < 0.001). Among patients, there was a significant correlation between the Tei index of the univentricular ventricle and rudimentary RV strain (r = ?0.66, p = 0.01). The heart rate-corrected intra-univentricular diastolic delay was significantly prolonged among patients when compared to the intra-LV diastolic delay in controls (0.01 ± 0.9 vs. 1 ± 1.1, p = 0.005).

Conclusions

Myocardial dysfunctions and intra-univentricular diastolic asynchrony of the univentricular heart in patients after Fontan procedure are evident. The rudimentary RV in patients after Fontan procedure plays an important role in the determination of the global function of the univentricular heart.     

Epicardial pacemaker implantation and follow-up in patients with a single ventricle after the Fontan operation

OBJECTIVES: There is an increasing incidence of sinus node dysfunction after the Fontan procedure. Inability to maintain atrioventricular synchrony after the Fontan operation has been associated with an adverse late outcome. Although pacing may be helpful as a primary or adjunct modality after the Fontan procedure, the effects of performing a late thoracotomy or sternotomy for epicardial pacemaker implantation are unknown. In addition, little is known about the long-term effectiveness of epicardial leads in patients with single ventricles. The purpose of this study was to compare the hospital course and follow-up of epicardial pacing lead implantation in patients with Fontan physiology and patients with 2-ventricle physiology. METHODS: We retrospectively reviewed all isolated epicardial pacemaker implantations and outpatient evaluations performed between January 1983 and June 2000. RESULTS: There was no difference in the perioperative course for the 31 Fontan patients (27 atrial and 41 ventricular leads [68 total]) compared with the 56 non-Fontan subjects (9 atrial and 61 ventricular leads [70 total]). The median length of stay in Fontan and non-Fontan patients was 3 and 4 days, respectively. There was no early mortality in either group. Pleural drainage for 5 days or longer was reported in 4% of the Fontan cohort and 3% of the non-Fontan group. Late pleural effusions were identified in only 2 patients in the Fontan group and 2 patients in the non-Fontan group. There was no significant difference in epicardial lead survival between the Fontan group and the non-Fontan group (1 year, 96%; 2 years, 90%; 5 years, 70%). The overall incidence of lead failure was 17% (24/138). CONCLUSIONS: Epicardial leads can be safely placed in Fontan patients at no additional risk compared to patients with biventricular physiology. Sensing and pacing qualities were relatively constant in both the Fontan and non-Fontan groups over the first 2 years after implantation.     

Short-term results of the Fontan operation in patients with Down syndrome

Despite an extensive experience with Fontan operation, there is a paucity of information to guide the indication of the procedure in patients with Down syndrome. Of 79 patients who had undergone a Fontan operation in our hospital between 1995 and 2003, 3 had Down syndrome. All 3 patients had complete atrioventricular septal defect with single ventricular physiology. Two patients survived, and 1 died of chylothorax and respiratory infection. The 2 survivors have done well in the short-term without complications. We consider that in appropriately selected patients with Down syndrome in whom biventricular repair is precluded, the Fontan operation is the choice of the procedures.     

Surgical outcomes of reoperation after Fontan completion

 Open in a separate windowOBJECTIVESPatients who have achieved Fontan circulation may require reoperation. We reviewed the outcomes of reoperation after Fontan completion and assessed the risk factors for poor outcomes.METHODSThis was a retrospective study of 106 patients undergoing open-heart reoperations after Fontan completion in 2003 at a single institution.RESULTSThe mean age at reoperation was 24.6 ± 8.3 years. A history of Fontan failure or end-organ dysfunction was noted in 30 patients. The reoperations included 73 total cavopulmonary connection conversions, 29 atrioventricular or semilunar valve operations (17 with total cavopulmonary connection conversions) and 4 other operations. Eight early deaths occurred. During a median follow-up of 5.5 (0.01–16.2) years, there were 3 late deaths and 9 second cardiac operations. The 10-year survival rate after reoperation was 89.8%, and the 5-year second cardiac operation-free survival was 84.3%. The 10-year survival rates were significantly lower in patients who underwent surgery before 2011 (75.8% vs 100%), had a history of Fontan failure or end-organ dysfunction (71.7% vs 97.3%), had preoperative central venous pressure >15 mmHg (64.9% vs 96.5%) and were operated on with deep hypothermic circulatory arrest (DHCA) (60.0% vs 91.3%). A history of Fontan failure or end-organ dysfunction, preoperative central venous pressure >15 mmHg and requirement of DHCA were identified as risk factors for mortality.CONCLUSIONSReoperation after Fontan completion resulted in excellent mid-term outcomes. A history of failed Fontan circulation and the requirement of DHCA negatively affected survival outcomes.     

Improving results of the modified Fontan operation in patients with heterotaxy syndrome

BACKGROUND: Historically the Fontan operation in patients with single ventricle heterotaxy syndrome and atrial isomerism has been associated with high mortality. We studied whether recent modifications of the surgical technique have improved outcome. METHODS: A retrospective review of 135 patients with heterotaxy syndrome who underwent a Fontan operation between 1981 and 2000 was performed. RESULTS: There were 93 patients with right isomerism and 42 with left isomerism. Anomalies of venous return included 25 patients with extracardiac pulmonary venous connection (19%) and 37 patients with an interrupted inferior vena cava (27%). Thirty-six patients (27%) had at least moderate atrioventricular valve regurgitation. The type of Fontan procedure included 17 patients with an atriopulmonary Fontan connection, 67 with a lateral tunnel modification, 19 with an intraatrial tube graft, 25 with an extracardiac tubegraft, and 7 with an intra-extra atrial tube graft. A fenestration was placed in 93 patients (78%). Early mortality was 19% before 1991, 3% since 1991, and no patient has died early since 1993. Ten-year survivals were 70% for Fontan operations before 1990 and 93% for Fontan operations after 1990. Thirty-two patients (23%) had prolonged pleural effusions. Risk factors for death included anomalous pulmonary venous connection (p = 0.02) and higher preoperative pulmonary vascular resistance (p = 0.002). Sixty-two patients (47%) had some form of early postoperative arrhythmia. At 10 years, freedom from late bradyarrhythmia and late tachyarrhythmia were 78% and 70%, respectively. Preoperative arrhythmias, older age at operation, and anatomic features were each independent predictors of late arrhythmia. CONCLUSIONS: The Fontan operation can now be performed in patients with heterotaxy syndrome with excellent survival. However, morbidity in terms of postoperative arrhythmias and prolonged pleural effusions remains significant. Fontan staging, appropriate choice of Fontan modification, aggressive treatment of concomitant malformations, and use of a baffle fenestration contribute to improved outcome.