[Forefoot relief with shoe inserts : Effects of different construction strategies]. / Vorfußentlastung durch Schuheinlagen : Effekte unterschiedlicher Konstruktionsprinzipien.

BACKGROUND: Shoe inserts and shoe modifications are used to reduce plantar peak pressure. The effects of different shoe inserts and shoe construction strategies for relief of the forefoot have not yet been sufficiently evaluated. PURPOSE: The aim of this study was to analyze the effects of shoe inserts and shoe construction strategies (e.g. metatarsal pad, forefoot cushioning and control) and shoe modifications (e.g. flexible or stiff) on the peak plantar pressure in the forefoot region. MATERIAL AND METHODS: In this study 15 healthy subjects were recruited. Plantar pressure distribution was measured using an in-shoe system during walking (3.5km∙h-1) on a treadmill and the average plantar peak pressure (kPa) in the forefoot was calculated. The statistics for testing the hypothesis were carried out using 2­factorial ANOVA with repeat measurements (factors: shoe, insert; α = 0.05). RESULTS: The metatarsal pad and forefoot cushioning led to a reduction of peak pressure, which was statistically significant compared to the control condition (p = 0.009). No differences were observed between both shoe inserts (p > 0.05). A comparison between stiff and flexible shoes revealed a statistically significant pressure reduction in favor of stiff shoes (p = 0.0001). The metatarsal pad led to a peak pressure increase in the midfoot of 12% and by 21% compared to control and forefoot cushioning, respectively. DISCUSSION: A peak pressure reduction in the forefoot can be achieved with a metatarsal pad or with cushioning; however, the metatarsal pad resulted in a subsequent increase in midfoot pressure. Moreover, shoe construction is crucial because a stiff shoe contributes to a better peak pressure reduction compared to a flexible shoe. Prospective clinical studies should be carried out to prove whether this results in beneficial effects for patients with metatarsalgia.

Long-term survival of aortic atresia following biventricular corrective surgery.

A female born with aortic atresia, large ventricular septal defect, normal mitral valve, and left ventricle is well at 21 years of age following biventricular repair. She had palliative surgery at 15 days and closure of ventricular septal defect with placement of a valved conduit from the left ventricular apex to descending aorta at 15 months. Conduit was replaced at 34 months and at 10 and 21.5 years of age.

The left-sided aortic arch in humans, viewed as the end-result of natural selection during vertebrate evolution.

At some point during vertebrate evolution from species dwelling in water to living on land, the ancestral double or right aortic arches became single and left-sided in mammals, including humans, as the result of synchronous developments in cardiovascular and respiratory embryogenesis. Since left-sided aortic arches are unique to mammals, hemodynamics related to the placenta, specifically the requirement for a large arterial duct connecting to the descending aorta, may have led to switching from the right-sided to the left-sided arch. Additionally, development of a trilobar right lung and its bronchial tree, also unique to mammalian evolution, restricted the space above the high eparterial bronchus to a single large vessel. Consequently, mammals that mutated to the left-sided aortic arch avoided respiratory, digestive or circulatory problems that are often associated with an isolated right-sided aortic arch--something which could be considered a successful mistake. Due to natural selection, and survival of the fittest, the left-sided arch became the norm in mammals. In congenital cardiac malformations where a large arterial duct is not mandatory in fetal life, as in Fallot's tetralogy or common arterial trunk, a right-sided aortic arch continues to occur, perhaps as an atavistic reversion to the anatomy seen in ancestral vertebrates.

Echocardiographic Doppler evaluation of left ventricular diastolic filling in older, highly trained male endurance athletes.

Previously published data have suggested that endurance training does not retard the normative aging impairment of early left ventricular diastolic filling (LVDF). Those studies, suggesting no effect of exercise training, have not examined highly trained endurance athletes or their LVDF responses after exercise. We therefore compared LVDF characteristics in a group of older highly trained endurance athletes (n = 12, mean age 69 years, range 65-75) and a group of sedentary control subjects (n = 12, mean age 69 years, range 65-73) with no cardiovascular disease. For all subjects, M-mode and Doppler echocardiographic data were obtained at rest. After baseline studies, subjects underwent graded, maximal cardiopulmonary treadmill exercise testing using a modified Balke protocol. Breath-by-breath respiratory gas analysis and peak exercise oxygen consumption (VO(2)max) measurements were obtained. Immediately after exercise and at 3-6 minutes into recovery, repeat Doppler echocardiographic data were obtained for determination of LVDF parameters. VO(2)max (44 +/-6.3 vs 27+/-4.2 ml/kg/min, P<0.001), oxygen consumption at anaerobic threshold (35+/-5.4 vs 24+/-3.8 ml/kg/min, P<0.001), exercise duration (24+/-3 vs 12+/-6 minutes, P<0.001), and left ventricular mass index (61+/-13 vs 51+/-7.8 kg/m(2), P<0.05) were greater in endurance athletes than in sedentary control subjects, whereas body mass index was lower (22+/-1.7 vs 26+/-3.4 kg/m(2), P<0.001). No differences in any of the LVDF characteristics were observed between the groups with the exception of a trend toward a lower atrial filling fraction at rest in the endurance athlete group versus the control subjects (P = 0.07). High-intensity endurance exercise training promotes exceptional peak exercise oxygen consumption and cardiovascular stamina but does not appear to alter normative aging effects on left ventricular diastolic function.

Bidirectional Glenn shunt in association with congenital heart repairs: the 1(1/2) ventricular repair.

BACKGROUND: The bidirectional Glenn shunt has been used to incorporate a smaller tripartite ventricle into the circulation and create pulsatile pulmonary artery flow. We reviewed our operative experience and assessed hemodynamics of the bidirectional Glenn shunt in 1(1/2) ventricular repair or in conjunction with other repairs of congenital heart defects. METHODS: Between 1992 and 1998, 15 patients (mean age, 8.1+/-7.9 years) had bidirectional Glenn shunt in association with repair of congenital heart defects. Eighty-seven percent had at least one previous operation. All patients had simultaneous or previous intracardiac repair and had bidirectional Glenn shunt to volume unload the small right ventricle (group A, n = 7), to unload the poorly functioning right ventricle (group B, n = 2), to redirect superior vena cava-pulmonary venous atrial connection to treat cyanosis (group C, n = 2), or to unload the pulmonary left ventricle for residual intracavitary hypertension in patients with L-transposition of the great arteries, ventricular septal defect, and pulmonary stenosis (group D, n = 4). Intraoperative hemodynamic assessment was done in 2 patients in group A by selective use of inflow occlusion and flow probes. RESULTS: All patients survived. Four patients had successful, concurrent arrhythmia circuit cryoablation for Wolf-Parkinson-White syndrome (n = 1) or atrial reentry tachycardia (n = 3). Superior and inferior vena caval flow averaged 36% and 64% of cardiac output, respectively. Postoperative superior vena caval pressure (n = 13) was 13.7+/-4.0 mm Hg with pulmonary arterial flow pattern contributed by the ventricle in systole (pulsatile) and the superior vena cava in diastole (laminar). CONCLUSIONS: The bidirectional Glenn shunt is an effective adjunct to congenital heart repair to treat pulmonary ventricular pressure-volume problems and anomalous superior vena caval to left atrial connections.

Is surgical ligation of an accessory left superior vena cava always safe?

In patients considered for bidirectional Glenn or Fontan procedures, the association of left superior vena cava (LSVC) with ostial atresia of the coronary sinus should be diagnosed preoperatively in order to avoid surgical division or ligation of the LSVC and the negative effect of resulting coronary venous hypertension on myocardial perfusion. This report discusses the angiographic and hemodynamic features of LSVC when it is the only drainage route from a blind coronary sinus. A retrograde flow in the LSVC seen by Doppler ultrasonography should raise the suspicion of this diagnosis.

Coronary artery fistulas in infants and children: a surgical review and discussion of coil embolization.

BACKGROUND: Coronary artery fistula (CAF) is a rare congenital anomaly that can be complicated by intracardiac shunts, endocarditis, myocardial infarction, or coronary aneurysms. Recent reports have emphasized the efficacy of percutaneous transcatheter techniques. The purpose of this article is to review a 28-year surgical experience with CAF as a standard for comparison and to discuss the emergence and efficacy of transcutaneous catheter coil embolization as an alternative form of therapy. METHODS: From 1968 to 1996, 17 patients (age, 6 weeks to 16.5 years; mean age, 5.5 years) were diagnosed with CAF: 8 of 12 by echocardiography and 17 of 17 by cardiac catheterization. All patients with isolated CAF (n = 13) were asymptomatic despite significant clinical, electrocardiographic, and chest roentgenographic findings in 10. Sixteen had congenital CAF and 1 had acquired CAF after tetralogy of Fallot repair with injury of the anomalous left anterior descending coronary artery. Associated anomalies included tetralogy of Fallot (2), atrial septal defect (1), and patent ductus arteriosus (1). Nine fistulas originated from the right coronary artery and eight from the left. Drainage was to the right ventricle (9), right atrium (4), pulmonary artery (3), and left atrium (1). RESULTS: All patients had a median sternotomy with epicardial or endocardial ligation. Cardiopulmonary bypass was used in 8; 1 of these (iatrogenic CAF) required distal internal mammary artery bypass graft. There were no operative or late deaths. Follow-up evaluation by physical examination (17), echocardiography (8), and catheterization (2) showed no evidence of recurrent or residual CAF. A retrospective review of the 16 available cine cardioangiograms showed that coil embolization was possible in, at most, 6 patients. CONCLUSIONS: Early surgical management of CAF is a safe and effective treatment resulting in 100% survival and 100% closure rate. Transcatheter embolization is a reasonable alternative to standard surgical closure in only a very small, select group of patients. These surgical results should be considered the standard against which transcatheter techniques are compared.

Taussig-Bing anomaly: arterial switch versus Kawashima intraventricular repair.

BACKGROUND: Current corrective surgical approaches for the Taussig-Bing heart include arterial switch with ventricular septal defect (VSD) closure and intraventricular repair as described by Kawashima. METHODS: Between 1983 and 1994, 20 children underwent intracardiac repair of Taussig-Bing anomaly. Mean age at operation was 17 months (range, 1 week to 9 years). Prior palliation included pulmonary artery band (15) with coarctation repair (8) and atrial septectomy (1). Arterial switch with VSD closure was performed in 16 patients, 10 with anteroposterior great arteries. Kawashima repair was performed in 4 patients, all with side-by-side great arteries. RESULTS: After arterial switch, there was one operative death (6.2%) due to myocardial ischemia and three late deaths (18.7%) due to pulmonary hypertension, gastrointestinal bleeding, and acute lymphocytic leukemia. In the Kawashima repair group there have been no deaths. After arterial switch, 9 patients underwent 11 reoperations for residual coarctation (3), residual pulmonary artery stenosis (2), aortic valve replacement, aortic valvuloplasty, unrecognized VSD, mitral valvuloplasty, mediastinitis, and pacemaker insertion. After Kawashima repair, 1 patient underwent reoperation for baffle stenosis and 1 for an unrecognized VSD. CONCLUSIONS: For children with Taussig-Bing anomaly, the Kawashima intraventricular repair (for side-by-side great arteries) preserves the native aortic valve and avoids coronary dissection. The arterial switch operation with VSD closure can be applied without ventriculotomy to all great artery relationships and allows neonatal repair with or without concomitant coarctation repair. Both techniques yield excellent early and intermediate-term results despite the high rates of prerepair palliation and postrepair reoperation for both groups.

Double-horned or caplike right ventricle: diagnosis and operative treatment.

BACKGROUND: Three patients reported here and 4 from the literature serve as background for the state-of-art diagnostic and operative considerations for an unusual congenital cardiac malformation: double-horned or caplike right ventricle. METHODS: This is a retrospective analysis of cardiac catheterization, cineangiography, and two-dimensional echocardiography findings, as well as palliative and corrective operations in 3 previously unreported patients. Four patients from the literature are reviewed. RESULTS: Characteristic morphologic features recognizable by invasive and noninvasive imaging distinguish double-horned right ventricle from complex malformations such as criss-cross hearts, superior-inferior ventricles, and univentricular hearts with a small outflow chamber. CONCLUSION: Double-horned or caplike right ventricle is a congenital malformation characterized by an unusual ventricular morphology, which may be the result of incomplete development of the right ventricle. The two-horned appearance may be secondary to an absence of the apical trabeculated compartment, with the left ventricle wedged between the two horns. It is invariably associated with double right ventricular outlet. Surgical experience so far suggest that most patients with typical double-horned right ventricle should be considered for anatomic surgical correction.

Expanding indications for pediatric coronary artery bypass.

Pediatric coronary artery bypass has been done mostly for ischemic complications of Kawasaki disease. We reviewed our clinical experience between 1987 and 1994 with internal thoracic artery-coronary artery bypass in one infant and five children for varying indications. Indications for coronary bypass included Kawasaki disease (2), congenital left main coronary ostial stenosis, iatrogenic coronary cameral fistula, anomalous origin of the left coronary artery from the pulmonary artery, and single coronary artery traversing between the great arteries in a patient after cardiac transplantation. An additional cohort of 34 control patients of various ages and weights (1 day to 16.1 years, 2.6 kg to 62 kg) had angiographic measurements of the right coronary, left coronary, and left internal thoracic arteries with respect to the feasibility of performing coronary artery bypass. All six patients survived internal thoracic artery-left anterior descending coronary artery bypass without evidence of perioperative myocardial infarction. Postoperative angiographic studies in five and color Doppler echocardiography in one showed graft patency. Retrospective angiographic measurements in the 34 control patients showed that internal thoracic and coronary arteries are proportionately quite large in neonates and infants compared with those in older children and adolescents. Internal thoracic artery-coronary artery bypass should be considered for the expanding indications presented herein and when emergency intraoperative life-threatening situations present themselves. Long-term patency and reoperation rates have yet to be determined.

Coarctation of the abdominal aorta.

Four patients with suprarenal coarctation of the abdominal aorta were managed from 1978 to 1993 (mean follow-up 8.75 years). Ages at the time of diagnosis were 2 months, 8 months, 4.5 years, and 15 years, respectively. Three children presented with severe hypertension, two of whom were in congestive heart failure, and the fourth child presented with a cold, ischemic leg. The 8-month-old patient had Williams syndrome (supravalvular aortic and pulmonic stenosis, bilateral renal artery stenosis and celiac artery occlusion, "elfin" facies, and mental retardation) and was treated nonoperatively. After 12 years of follow-up, he was given five medications to control hypertension, cardiac arrhythmias, and heart failure. Three patients with abdominal aortic coarctation were treated operatively and none died. Two patients underwent bypass grafting from the supraceliac aorta to the infrarenal aorta, with bilateral renal artery reconstruction in one. Postoperative arteriograms obtained 1 year or more after operation were normal in both cases. The 2-month-old patient underwent patch aortoplasty, with subsequent reoperation 1.5 years later for recurrent hypertension and heart failure with a bypass graft to the left kidney and removal of an infarcted right kidney. In all three patients, operative repair of the suprarenal aortic coarctation has resulted in long-term control of blood pressure and cardiac and renal function.

Management of hypoplastic aortic arch associated with neonatal coarctation.

Controversy still exists as to whether hypoplastic aortic arch frequently associated with neonatal coarctation, should be enlarged at the time of coarctation repair. To determine the indications for and the outcome of repair of hypoplastic aortic arch, pre- and postoperative angiograms/echocardigraphy of 77 cases with isolated (n = 25, Group 1) or complex (n = 52, Group 2) neonatal coarctation operated upon between 1/80 and 12/89 were reviewed. Age was 5-14 days (mean 8 +/- 1.6). Aortic arch/ascending aorta diameter ratio (AR/AA) as a measure of the degree of aortic arch hypoplasia was 0.39-0.64 (0.52 +/- 0.04) in isolated and 0.15-0.47 (0.34 +/- 0.06) in complex coarctation (p < 0.05). Left subclavian flap aortoplasty was used in 72 patients; alone in 25, in combination with pulmonary artery banding in 43 patients, and simultaneously with intracardiac repair in 4 patients. Extensive reconstruction of aortic arch and coarctation with synthetic patch was performed in the remaining 5 patients (AR/AO = 0.16 +/- 0.03) using cardiopulmonary by-pass at the time of intracardiac repair. Operative mortality was 2/76 (2.5%). Follow-up is 6.6 +/- 1.4 years. Recoarctation occurred in 3 patients (4%). AR/AA increased to 0.86 +/- 0.1 in isolated (p < 0.05 vs preoperative) and to 0.7 +/- 0.1 in complex coarctation (p < 0.05 vs preoperative). In the majority of cases, hypoplastic aortic arch associated with coarctation grows satisfactorily following simple repair of coarctation with no significant residual narrowing.(ABSTRACT TRUNCATED AT 250 WORDS)

Normal left ventricular muscle mass and mass/volume ratio after pediatric cardiac transplantation.

BACKGROUND: The adaptive growth of the transplanted heart within the growing child may contribute to long-term cardiac performance. The ability to achieve increased ventricular volume and appropriate muscle mass in the face of immunosuppression and cardiac denervation has not been studied. We previously reported normal left ventricular (LV) volume growth over a 3-year period after cardiac transplantation. This study was designed to assess changes in LV mass and mass/volume ratio and their relation to LV end-diastolic pressure (LVEDP) 1 to 4 years after cardiac transplantation. METHODS AND RESULTS: Cardiac transplantation was performed in 18 patients, age 7 days to 18 years (median, 3.7 years). The indications for cardiac transplantation were cardiomyopathy (8 patients), hypoplastic left heart syndrome (7 patients), and postoperative structural congenital heart disease with ventricular failure (3 patients). The mean follow-up was 48 months, with a range from 29 to 70 months. Serial annual catheterizations were performed after 1 year (16 patients), 2 years (18 patients), 3 years (15 patients), and 4 years (8 patients). Cardiac index (Fick), LVEDP (baseline and after 10-mL/kg saline infusion delivered over 5 minutes), and systemic vascular resistance (SVR) were measured. LV diastolic volume index (LVDVI), LV mass index, and mass/volume ratio were determined angiographically according to the method of Lange and Rackley. The data were analyzed by repeated-measures ANOVA. Least-squares means and group SEM were calculated. No change in cardiac index, SVR, or baseline LVEDP was noted. The LVEDP doubled after fluid challenge, suggesting a restrictive process. The LVDVI remained near 60 mL/m2. The LV mass/volume ratio remained one. CONCLUSIONS: Appropriate increases in muscle mass occurred after cardiac transplantation, preserving normal mass/volume ratios despite somatic growth deficits associated with immunosuppressive therapy and denervation of the donor heart.

Restrictive ventricular septal defect: how small is too small to close?

Historically, indications for ventricular septal defect closure have included congestive heart failure, pulmonary hypertension, aortic insufficiency with or without aortic valve prolapse, and prior bacterial endocarditis. However, controversy exists as to how the lifetime risk of an isolated, nonoperated restrictive ventricular septal defect compares with the risk of surgical closure in an asymptomatic child. Between 1980 and 1991, cardiac catheterization and elective ventricular septal defect closure (age > 1 year, pulmonary to systemic flow ratio < 2.0) were performed in 141 patients aged 1 to 23 years (mean age, 6.1 +/- 4.7 years). Mean systolic pulmonary artery pressure was 26.9 +/- 13.0 mm Hg, and mean pulmonary to systemic flow ratio was 1.6 +/- 0.3. Aortic valve prolapse was present in 63 patients (45%), aortic insufficiency was present in 25 (18%), and 5 (3.5%) had prior bacterial endocarditis. There were no early or late deaths or major morbidity. No patient required a ventriculotomy to accomplish ventricular septal defect closure. Mean postoperative intensive care unit stay was 1.3 +/- 0.9 days, and mean hospital stay was 5.5 +/- 1.9 days. There were no instances of permanent complete atrioventricular dissociation, reoperations for bleeding, postoperative wound infections, or reoperations for residual or recurrent ventricular septal defect. These improved results justify a reevaluation of historic indications for ventricular septal defect closure.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of the Hemashield extension in right ventricle-to-pulmonary artery conduits.

Between 1989 and 1991, 17 children underwent 18 right ventricle-to-pulmonary artery conduit placement operations using a composite of an aortic or pulmonary valved homograft and a Hemashield extension to the ventricle. Hemashield is a collagen-coated knitted Dacron graft with excellent compliance and hemostatic properties. Diagnoses included tetralogy of Fallot with pulmonary atresia (7), truncus arteriosus (6), and complex transposition of the great arteries (4). Mean age at conduit placement was 4.9 +/- 4.2 years, and all patients survived. At a mean follow-up of 14 +/- 4 months, postoperative Doppler echocardiographic gradients between the ventricle and pulmonary artery ranged from less than 20 to 60 mm Hg. At cardiac catheterization 13 +/- 3 months postoperatively (6 patients), the systolic pressure gradient across the conduits ranged from 14 to 90 mm Hg (mean gradient, 59 +/- 29 mm Hg). Conduit obstruction, when present, was demonstrated angiographically to be in the Hemashield portion and led to early conduit replacement six times in 5 patients (33% of operations) within 10 to 18 months (mean time, 14 months) after insertion of the original conduit. Pathologic examination of the explanted conduits revealed the obstruction to be a thick neointimal peel that was impossible to separate from the Hemashield graft. Failure of the Hemashield as an extension for ventricle-to-pulmonary artery conduits secondary to accelerated neointimal formation has led us to abandon its use in clinical practice.

Biventricular repair of hypoplastic right ventricle assisted by pulsatile bidirectional cavopulmonary anastomosis.

The right ventricle in patients with severe outflow obstruction or atresia and a small tricuspid valve often remains too hypoplastic even after optimal palliation to tolerate biventricular repair with closure of the atrial septal defect. In these patients, nonpulsatile cavopulmonary (Glenn) anastomosis has traditionally facilitated biventricular repair. In 1989, Billingsley and associates reported the addition of a bidirectional cavopulmonary anastomosis to the definitive biventricular repair in patients with hypoplastic right ventricle, pulmonary atresia, and intact ventricular septum. The atrial septal defect was left open with an adjustable snare for later closure. We report five patients with hypoplastic right ventricle (mean diastolic volume 48.4%, mean stroke volume 40.2% of predicted value) who had the atrial septal defect closed at the time of the biventricular repair. Four patients, who had the bidirectional cavopulmonary anastomosis supplementing the biventricular repair, had no evidence of excessive right atrial or superior vena cava hypertension postoperatively. One patient, who had atypical tetralogy of Fallot with tricuspid stenosis, developed recurrent pericardial tamponade and marked hepatomegaly following conventional tetralogy repair with closure of the atrial septal defect. These complications were controlled with the addition of bidirectional cavopulmonary anastomosis 2 months later. Postoperative hemodynamic or Doppler studies in these patients revealed pulsatile flow in the entire pulmonary artery system, including the artery distal to the Glenn anastomosis. This modification of biventricular repair allows primary closure of the atrial septal defect and provides pulsatile arterial flow in the entire pulmonary artery, even when the right ventricle is significantly hypoplastic.

Ventricular volume growth after cardiac transplantation in infants and children.

BACKGROUND: Intermediate-term survival after pediatric cardiac transplantation continues to improve. However, little is known about cardiac function and especially ventricular growth in young patients after cardiac transplantation. The purpose of this study was to evaluate serially the hemodynamics, left ventricular (LV) volume, and ventricular function after cardiac transplantation in infants and children. METHODS AND RESULTS: Indications for cardiac transplantation were dilated cardiomyopathy (eight patients), hypoplastic left heart syndrome (six patients), and postoperative structural congenital heart disease (three patients). The age at time of transplant ranged from 7 days to 15 years (median, 3.5 years). The mean follow-up was 30.3 months (range, 13-46 months). Serial annual cardiac catheterizations were performed 1 year (17), 2 years (15), and 3 years (seven) after transplant. Measurements included right and left heart pressures, cardiac index, and LV volume and ejection fraction (Lange). Cumulative results (expressed as mean +/- SD) were pulmonary artery pressure, 14.9 +/- 3.2 mm Hg; LV end-diastolic pressure, 7.7 +/- 2.6 mm Hg; cardiac index, 3.5 +/- 0.52 l/min.m-2; and pulmonary vascular resistance, 2.02 +/- 0.76 units/m2. LV end-diastolic volume increased as patients grew, so that left ventricular end-diastolic volume remained 90 +/- 14% of that predicted for body surface area. The ejection fraction was 99 +/- 6% of that predicted. There was no evidence of chronic rejection by endomyocardial biopsy. No accelerated coronary artery atherosclerosis was identified. CONCLUSIONS: Serial studies in these young patients demonstrate normal hemodynamics and LV function after cardiac transplantation. Cardiac transplantation is associated with normal LV volume growth despite immunosuppression and denervation.

Fenestrated Fontan with delayed catheter closure. Effects of volume loading and baffle fenestration on cardiac index and oxygen delivery.

BACKGROUND. The fenestrated Fontan operation has been applied to high-risk patients with univentricular hearts, resulting in improved survival. The purpose of this study was to determine the hemodynamic factors responsible for these improved results. METHODS AND RESULTS. We performed the fenestrated Fontan operation in 17 high-risk patients with univentricular hearts (median age, 3 years; age range, 1.2-25 years). High-risk characteristics were depressed ventricular function and/or hypertrophy (n = 12), atrioventricular valve insufficiency (n = 5), pulmonary artery distortion (n = 6), elevated pulmonary vascular resistance (> 2 units/m2) (n = 4), previously failed Fontan operation (n = 2), or associated Wolff-Parkinson-White syndrome (n = 1). Intraoperative hemodynamic measurements (n = 8) included cardiac index (by aortic flow probe), peripheral arterial O2 saturations, and left and right atrial pressures during inflow occlusion, followed by volume loading with open versus closed fenestration. Mean baffle fenestration was 3.5 mm (range, 2.7-5.0 mm). Multiple regression analysis (cardiac index versus atrial pressure) revealed cardiac index was greater with open than with closed fenestration (p < 0.001) during volume loading. Oxygen delivery (cardiac index multiplied by oxygen content) was also greater with open than with closed fenestration (p < 0.001). Survival was 100% with a mean follow-up of 10.4 months; pleural drainage was high in two patients. Subsequent transcatheter fenestration closure resulted in increased O2 saturation (87 +/- 1% to 96 +/- 0.3%, p < 0.05). CONCLUSIONS. The fenestrated Fontan operation improves survival in high-risk patients by increasing cardiac index and maintaining oxygen delivery, despite mild arterial O2 desaturation. Subsequent transcatheter fenestration closure can be performed after hemodynamic assessment.