Acute Kidney Injury and Renal Replacement Therapy After Fontan Operation

Fontan circulation leads to chronic elevation of central venous pressure. We sought to identify the incidence, risk factors, and survival among patients who developed acute kidney injury (AKI) after the Fontan operation. We retrospectively reviewed 1,166 patients who had Fontan operation/revision at Mayo Clinic Rochester from 1973 to 2017 and identified patients who had AKI (defined by AKI Network criteria) within 7 days of surgery. A total of 132 patients (11%) developed AKI after the Fontan operation with no significant era effect. Of those who developed AKI, severe (grade 3) kidney injury was present in 101 patients (76.5%). Multivariable risk factors for AKI were asplenia (odds ratio [OR] 4.2, p <0.0001), elevated preoperative pulmonary artery pressure (per 1 mm Hg increase, OR 1.04, p = 0.0002), intraoperative arrhythmias (OR 1.9, p = 0.02), and elevated post-bypass Fontan pressure (per 1 mm Hg increase, OR 1.12, p = 0.0007). Renal replacement therapy (RRT) was used in 72 patients (54%), predominantly through peritoneal dialysis (n = 56, 78%). Multivariable risk factors for RRT were age ≤3 years (OR 9.7, p = 0.0004), female gender (OR 2.6, p = 0.02), and aortic cross-clamp time >60 minutes (OR 3.1, p = 0.01). Patients with AKI had more postoperative complications, including bleeding, stroke, pericardial tamponade, low cardiac output state and cardiac arrest, than those without AKI. This resulted in longer intensive care unit stay (39 vs 17 days, p = 0.0001). In-hospital mortality was exceedingly higher among patients with AKI versus no AKI (58%, 76 of 132 vs 10%, 99 of 1,034, p <0.0001); however, there was no significant difference based on the need for RRT. Recovery from AKI was observed in 56 patients (42%). Over 20-year follow-up, patients with AKI had a distinctly higher all-cause-mortality (82%) than those without AKI (35%). It is prudent to identity patients at a higher risk of developing postoperative AKI after Fontan operation to ensure renal protective strategies in the perioperative period. Postoperative AKI leads to substantial short and long-term morbidity and mortality, but the need for RRT does not affect the outcomes.

Skin-Related complications of Klippel-Trenaunay Syndrome: a retrospective review of 410 patients

BACKGROUND

Little is known about skin-related complications in Klippel-Trenaunay syndrome (KTS), a complex vascular anomaly defined by capillary malformation (CM), venous malformation (VM) ± lymphatic malformation (LM) and limb overgrowth. Reported skin-related complications of KTS include ulceration, vascular ectasias (blebs), bleeding and infection.

OBJECTIVE

To determine the spectrum, prevalence and predictors of skin-related complications in KTS.

METHODS

A retrospective review of 410 patients fulfilling KTS criteria was performed to assess for the presence of skin-related complications.

RESULTS

Skin-related complications were present in 45% of patients. Most prevalent were CM-related complications including blebs, bleeding, thickening (25%), cellulitis (22%) and ulceration (21%). Features positively associated with skin-related complications were presence of LM (OR 17.17; P < 0.001), VM on the buttocks/perineum/genitalia (OR 1.92; P = 0.009), CM on the feet (OR 1.77; P = 0.039) and male sex (OR 1.63; P = 0.034). Features negatively associated with skin-related complications were CM on the trunk (OR 0.59; P = 0.029) and tissue hypertrophy of the hands (OR 0.27; P = 0.025).

CONCLUSION

Skin-related complications affect nearly half of patients with KTS. Those with lymphatic involvement or malformation presence in the undergarment area or feet are most at risk.

Total Knee Arthroplasty Is Safe and Successful in Patients With Klippel-Trénaunay Syndrome

BACKGROUND

Klippel-Trénaunay syndrome (KTS) is a severe vascular malformation that can lead to hypertrophic osteoarthritis. Total knee arthroplasty (TKA) performed in extremities affected with KTS is challenging given the high-risk vascular considerations and occasionally poor bone quality.

METHODS

We identified 12 patients with KTS who underwent TKA between 1998 and 2017. There were 7 men, mean age 42 years, and mean follow-up was 7 years. Before arthroplasty, 2 patients (17%) had preoperative sclerotherapy. Preoperative vascular studies were done for 9 patients (75%) and included magnetic resonance imaging (n = 7), magnetic resonance angiography (n = 1), and computed tomography angiography (n = 1). A preoperative blood conservation protocol was used for all operations and included the use of tranexamic acid (TXA) in later years. Posterior-stabilized TKA was used in 10 cases and cruciate-retaining TKA was used in 2 cases.

RESULTS

At final follow-up, 2 patients (17%) had undergone revision surgery: 1 for infection and 1 for tibial loosening with subsequent arthrofibrosis. Knee Society Scores (36-83, P < .0001) and functional scores (48-84, P = .0007) significantly increased between the preoperative and postoperative period. Likewise at last follow-up, the mean knee range of motion significantly increased (82°-104°, P = .04). Median blood loss for patients who received TXA was 200 mL compared to 275 mL in patients who did not receive TXA (P = .66). Likewise there was no difference (P = .5) in the proportion of patients who required a transfusion between those who received TXA (2/6, 33%) and those who did not (3/6, 50%).

CONCLUSION

In this small series, TKA can lead to significant clinical improvement for patients with KTS. Modern blood management techniques and a careful multidisciplinary care approach render TKA a reasonable option for select patients with KTS.

LEVEL OF EVIDENCE

Level IV case series, therapeutic.

Fontan Failure Secondary to Charcot-Marie-Tooth-Induced Phrenic Neuropathy

Charcot-Marie-Tooth disease comprises a vast array of defects in myelin integrity that causes progressive peripheral sensorimotor neuropathy. It is the most prevalent inherited peripheral neuropathy, and it can affect the management of coexisting medical conditions. We report the case of a 25-year-old woman who had undergone successful Fontan surgery during childhood, but her Fontan circulation failed as a result of diaphragmatic paresis caused by Charcot-Marie-Tooth disease type 1A. This diagnosis precluded cardiac transplantation.

Idiopathic Restrictive Cardiomyopathy in Children and Young Adults

Idiopathic restrictive cardiomyopathy (IRC) is a rare condition characterized by reduced ventricular compliance. Children with IRC have poor outcomes with most patients proceeding to cardiac transplantation. We sought to analyze our institutional experience and assess contemporary outcomes for children with IRC. We reviewed the medical record for patients (<21 years old) evaluated for a primary diagnosis of IRC between 1975 and 2013 at our institution. Demographic, clinical, echocardiographic, and catheterization data were abstracted. The patients were divided into 2 groups comprising a historical cohort (HC) (diagnosis: 1975 to 1993, n = 8) and a contemporary cohort (CC) (diagnosis: 1994 to 2013, n = 12). Twenty children were identified with IRC (mean age at presentation 9.7 ± 6.5 years, 55% female). Mean length of follow-up was 6.5 ± 8.4 years (range 0.1 to 35.6 years). In the CC, 7 of 12 patients (58%) progressed to cardiac transplantation (mean age of 9 ± 4 years at transplant, mean interval from diagnosis of IRC: 1.5 ± 0.9 years). Overall survival was improved significantly in the CC compared with the HC (80% vs. 38%, p = 0.02), but transplantation free survival was no different between the CC and HC over 5 years (38% vs 38%, p = 0.65). In the CC, elevation of mitral valve Doppler E/e' ratio on echocardiography was associated with increased mortality (p = 0.01). In conclusion, IRC continues has a poor prognosis. Early referral for transplantation was associated with improved overall survival in the modern era. Patients with markedly elevated E/e' ratio may have increased risk of death.

Klippel–Trenaunay Syndrome: Current Management

Klippel–Trenaunay syndrome (KTS) is a rare, sporadic, complex malformation characterized by the clinical triad of (1) capillary malformations (port wine stain); (2) soft tissue and bone hypertrophy or, occasionally, hypotrophy of usually one lower limb; and (3) atypical, mostly lateral varicosity. KTS is a mixed vascular malformation, with predominant capillary, venous and lymphatic components, without significant arteriovenous shunting. Management is largely conservative and the extent of diagnostic evaluation is determined by the planned treatment. Compression is the hallmark of conservative management; laser can be used to treat port wine stains. Imaging before vascular interventions must confirm venous anatomy and deep venous drainage. Techniques for ablation of superficial veins and malformations are individualized and may include sclerotherapy with alcohol or foam, endovenous thermal ablation or, as used most frequently in our practice, surgical stripping and phlebectomy. Intraoperative use of tourniquet will decrease bleeding, selective use of an inferior vena cava filter will prevent pulmonary embolism. A multidisciplinary approach to management of KTS is warranted.

Prevalence and outcome of thrombotic and embolic complications in adults after Fontan operation

There are limited studies of thrombotic and embolic complications (TEC) in the adult Fontan population. The purpose of the study was to determine the prevalence, risk factors, and outcomes of TECs in this population.

METHODS

Retrospective review of adults with a previous Fontan operation, with follow-up at Mayo Clinic, 1994-2014. Systemic TEC was defined as intracardiac thrombus, ischemic stroke, or systemic arterial embolus. Nonsystemic TEC was defined as Fontan conduit/right atrial thrombus or pulmonary embolus.

RESULTS

We identified 387 patients with a mean (SD) age of 28 (7) years and a mean follow-up of 8 (2) years. An atriopulmonary connection (APC) was done for 286 patients (74%). Atrial arrhythmias were present in 278 (72%). There were 121 TECs (systemic n=36, nonsystemic n=85) in 98 patients (25%). Risk factors for systemic TEC were atrial arrhythmia (hazard ratio 2.28, P=.001) and APC (hazard ratio 1.98, P=.02); nonsystemic TEC also had similar risk factors. All 98 patients received warfarin. Warfarin was discontinued in 10 of 98 because of bleeding, and 8 of these 10 subsequently had a second TEC. Among the 82 patients who had follow-up imaging, 16 (20%) had resolution of thrombus. In total, 24 of 98 patients had a second TEC, most of whom had inadequate anticoagulation.

CONCLUSIONS

Thrombotic and embolic complication was not uncommon; risk factors for TEC were APC and atrial arrhythmias. Most patients were treated successfully with warfarin alone. A second TEC occurred in most patients whose anticoagulation was discontinued because of bleeding events.

Heart transplantation after Fontan: Results from a surgical Fontan cohort

We performed a retrospective review of outcomes after heart transplantation during long-term follow-up of a surgical cohort of 1138 Fontan patients who were followed at the Mayo Clinic. Follow-up information was obtained from medical records and a clinical questionnaire that was mailed to patients not known to be deceased at the initiation of the study. Forty-four of 1138 Fontan patients with initial or subsequent evaluation at Mayo had cardiac transplantation between 1988 and 2014 (mean age at transplantation was 23.2 ± 12 yr, median was 19.8 yr; mean interval between Fontan and transplantation was 13.0 ± 7.7 yr, median was 13.1 yr). Two patients had combined organ transplantation (one heart-lung, one heart-liver). Twelve of the 44 (27%) patients had PLE prior to transplantation. There was no difference in post-bypass Fontan pressures or incidence of late reoperations for AVV repair/replacement between transplanted and non-transplanted patients. There were 16 (36%) deaths in the transplantation cohort; seven occurred within 30 days of transplantation. Overall one, five, 10, and 15 yr post-transplantation survival was 80%, 72%, 69%, and 55%, respectively. Although this is a challenging group of patients, intermediate-term results suggest that cardiac transplantation remains a reasonable option for patients with a failed Fontan circulation.

Cardiopulmonary exercise performance is reduced in congenital diaphragmatic hernia survivors

BACKGROUND

Congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia. CDH survivors may have pulmonary morbidity that can decrease cardiopulmonary exercise. We aimed to examine whether cardiopulmonary exercise testing (CPET) results differ in CDH survivors versus healthy age-matched controls and whether CPET results among CDH survivors differ according to self-reported daily activity.

METHODS

In one medical center in Croatia, CDH survivors-patients with surgically corrected CDH who were alive at age 5 years-were invited to participate in spirometry and CPET. Values were compared with those of controls matched 2:1 by age and sex for each CDH survivor aged 7 years or older.

RESULTS

Among 27 CDH survivors aged 5-20 years, 13 (48%) had continued symptoms or spirometric evidence of pulmonary disease. Compared with controls (n = 44), survivors (n = 22) had lower peak oxygen consumption (V˙O2 mean [SD], 35.7 [6.9] vs. 45.3 [8.2] ml/kg per min; P < 0.001). At peak exercise, V˙O2/heart rate (P < 0.001), tidal volume (P = 0.005), and minute ventilation (P < 0.001) were lower in survivors, but the maximal respiratory rate was not different (P = 0.72). Among survivors, mean (SD) V˙O2peak (ml/kg per min) differed by self-reported activity level: athletic, 40.3 (5.0); normal, 35.8 (6.5); and sedentary, 32.1 (6.8) (by ANOVA, P = 0.10 across three groups and P = 0.04 athletic vs. sedentary).

CONCLUSION

More than half of CDH survivors continue to have chronic pulmonary disease. CDH survivors had lower aerobic exercise capacity than controls. Self-reporting information on daily activities may identify CDH patients with low V˙O2max who may benefit from physical training. Pediatr Pulmonol. 2016;51:1320-1329. © 2016 Wiley Periodicals, Inc.

Liver Disease in Patients After the Fontan Operation

We reviewed records of all patients with an initial Fontan operation or revision from 1973 to 2012 at our institution (n = 1,138); 195 patients had postoperative liver data available. Cirrhosis was identified by histopathology or characteristic findings on imaging with an associated diagnosis of cirrhosis by a hepatologist. Of 195 patients with biopsy or imaging, 10-, 20-, and 30-year freedom from cirrhosis was 99%, 94%, and 57%, respectively. There were 40 of 195 patients (21%) diagnosed with cirrhosis (mean age at Fontan 10.7 ± 8 years). On multivariate analysis, hypoplastic left heart syndrome was associated with increased risk of cirrhosis (n = 2 of 16, p = 0.0133), whereas preoperative sinus rhythm was protective (p = 0.009). Survival after diagnosis of cirrhosis was 57% and 35%, at 1, and 5 years, respectively. The cause of death was known for 9 patients (5 multiorgan failure, 2 liver failure, and 2 heart failure). In conclusion, there is an incremental occurrence of cirrhosis after the Fontan, which should be considered when designing follow-up protocols for patients after Fontan operation.

EVALUATION OF PLASMA SUBSTANCE P AND BETA-ENDORPHIN LEVELS IN CHILDREN WITH PRADER-WILLI SYNDROME

BACKGROUND

Prader-Willi syndrome (PWS) is a rare obesity-related genetic disorder often caused by a deletion of the chromosome 15q11-q13 region inherited from the father or by maternal disomy 15. Growth hormone deficiency with short stature, hypogonadism, cognitive and behavioral problems, analgesia, decreased gastric motility and decreased ability to vomit with hyperphagia are common in PWS leading to severe obesity in early childhood, if not controlled. Substance P (SP) and beta-endorphin (BE) are neuropeptides involved with centrally and peripherally mediated pain perception, emotional regulation, and gastric motility impacting nausea, emesis and feeding patterns.

OBJECTIVE

The goal of this study was to investigate potential mechanisms for PWS symptom development for pain, emotion and gastric motility and plasma levels of substance P and beta-endorphin between PWS and unrelated unaffected children.

METHODOLOGY

Plasma samples were collected from 23 Caucasian children with PWS and 18 unrelated, unaffected siblings with an average age of 8.2 ±2.0 years and age range of 5 to 11 years following an overnight fast and neuropeptide substance p and beta-endorphin levels were assessed using Multiplex sandwich immunoassays using the Luminex magnetic-bead based platform. Linear regression analysis was carried out on log-transformed values adjusted for age, sex, and body mass index (BMI).

RESULTS

The mean plasma SP (57 ± 23 pg/ml) and BE (592 ± 200 pg/ml) levels in PWS were significantly higher than SP (35 ± 20 pg/ml, F=10.5, P<0.01) and BE (402 ± 162 pg/ml, F=10.8, P<0.01) levels found in unrelated, unaffected siblings suggesting a previously uncharacterized neuroendocrine pathophysiology in PWS.

CONCLUSIONS

The increased BE and SP plasma levels relative to unrelated, unaffected siblings may contribute to hyperphagia, abnormal pain sensation and adrenal insufficiency seen in PWS. Increases in SP levels may be modulated by central and/or peripheral actions of BE on opioid, GABA or POMC precursors and may reflect loss of feedback inhibitory control. Further studies are needed to confirm and elucidate the biochemical basis for observed disturbances in neuropeptide levels seen in our study and may impact on the development and persistence of symptoms commonly seen in PWS.

Transition of care in congenital heart disease from pediatrics to adulthood

Improvement in surgical techniques, anesthesia, and perioperative care has resulted in the majority of children born with congenital heart defects surviving into adulthood with a normal or near-normal quality of life. A careful transition from pediatric to adult care providers is important to avoid issues related to loss of continuity of care and any undue financial or psychological burdens to the patients and their families. The patients, their families, and the health care providers are faced with many challenges during this transition process that can be optimized and overcome by education about the heart defects and a team approach with clear lines of communication. This review addresses the challenges related to the transition of care from pediatrics to adults and provides the necessary recommendations to ensure a smooth transition process.

Clinical outcomes and improved survival in patients with protein-losing enteropathy after the Fontan operation

BACKGROUND

Patients with protein-losing enteropathy (PLE) following the Fontan operation have a reported 50% mortality at 5 years after diagnosis.

OBJECTIVES

The aim of this study was to review outcomes in patients with PLE following the Fontan operation.

METHODS

From 1992 to 2010, 42 patients (55% male) with PLE following the Fontan operation were identified from clinical databases at the Mayo Clinic. Data were collected retrospectively.

RESULTS

Mean age at PLE diagnosis was 18.9 ± 11.0 years. Initial Fontan operation was performed at 10.1 ± 10.8 years of age. Mean time from Fontan operation to PLE diagnosis was 8.4 ± 14.2 years. Survival was 88% at 5 years. Decreased survival was seen in patients with high Fontan pressure (mean >15 mm Hg; p = 0.04), decreased ventricular function (ejection fraction <55%; p = 0.03), and New York Heart Association functional class >2 at diagnosis (p = 0.04). Patients who died had higher pulmonary vascular resistance (3.8 ± 1.6 Wood units [WU] vs. 2.1 ± 1.1 WU; p = 0.017), lower cardiac index (1.6 ± 0.4 l/min/m(2) vs. 2.7 ± 0.7 l/min/m(2); p < 0.0001), and lower mixed venous saturation (53% vs. 66%; p = 0.01), compared with survivors. Factors were assessed at the time of PLE diagnosis. Treatments used more frequently in survivors with PLE included spironolactone (21 [68%]), octreotide (7 [21%]), sildenafil (6 [19%]), fenestration creation (15 [48%]), and relief of Fontan obstruction (7 [23%]).

CONCLUSIONS

PLE remains difficult to treat; however, in the current era, survival has improved with advances in treatment. Further study is needed to better understand the mechanism of disease and ideal treatment strategy.

Cardiac and multiorgan transplantation for end-stage congenital heart disease

OBJECTIVE

To report our single-center experience with patients who had cardiac and multiorgan transplantation for end-stage congenital heart disease (CHD).

PATIENTS AND METHODS

We reviewed records for all patients with CHD who had undergone heart transplantation at Mayo Clinic, Rochester, Minnesota, from November 1, 1990, through June 30, 2012. Patients with cardiomyopathy were excluded, unless CHD was present.

RESULTS

Overall, 45 patients had cardiac transplantation for end-stage CHD (mean age, 26.1±18.4 years; range, 1 month to 65 years). Two patients (4%) had combined heart/liver transplantation; 1 (2%) had heart/kidney transplantation. Six patients (13%) had no previous cardiac operation; the remaining 39 patients had a mean of 3 (range, 1-8) previous cardiac operations. Patient survival (95% CI) at 1, 5, and 10 years was 89% (80%-98%), 89% (80%-98%), and 72% (56%-87%), respectively, while graft survival at 1, 5, and 10 years was 89% (80%-98%), 89% (80%-98%), and 61% (44%-78%), respectively. During the same era, the International Society for Heart & Lung Transplantation reported that survival in patients undergoing transplant for non-congenital diagnoses was 85%, 72%, and 56%, respectively. Over a mean follow-up of 8.7±6.2 years, rejection requiring treatment was documented in 35 patients (78%). Eleven patients (24%) have been diagnosed with neoplasia (8 skin, 1 blood, 1 lymph, and 1 other), and 3 patients (7%) have required retransplantation. Four patients (9%) have developed significant coronary vasculopathy; 1 successfully underwent retransplantation, and 3 died 6, 8, and 14 years after transplantation.

CONCLUSION

With appropriate patient selection and posttransplant monitoring, survival has improved for patients with complex end-stage CHD. Multiorgan transplantation is an option for selected patients with CHD.

Empiric switch from calcineurin inhibitor to sirolimus-based immunosuppression in pediatric heart transplantation recipients

Sirolimus is used in heart transplant patients with CAV and CNI-induced nephropathy. However, little is known regarding the tolerability, rejection rate, and effect on renal function when used empirically in children. We describe our experience with the empiric use of a sirolimus-based immunosuppressive regimen in pediatric heart transplantation recipients. We reviewed records of patients in whom conversion was attempted to a CNI-free sirolimus-based regimen. Rejection episodes and measures of renal function were recorded. We attempted to convert 20 patients, of which 16 were successful. In total, six of 20 patients (30%) experienced adverse effects. Of the 16 converted, four patients converted to sirolimus due to CNI-induced disease (three nephropathy, one CAV), while 12 patients (mean age 5.5 yr, range 0.1-21 yr; 33% female; 33% with a history of congenital heart disease) were empirically switched to sirolimus at a mean of 2.3 yr after transplant. Follow-up was available for a mean of 2.5 yr after conversion (range 0.5-8.3 yr). The rate of rejection while taking CNIs was 0.18 rejection episodes per patient-year (total of five episodes), compared with 0.03 rejection episodes per patient-year (total of one episode) while on sirolimus. Renal function, in terms of GFR, significantly improved after sirolimus conversion at latest follow-up (from 86 ± 37 mL/min to 130 ± 49 mL/min, p = 0.02). Here, we demonstrate the potential benefit of empiric use of sirolimus in pediatric heart transplant patients in a CNI-free regimen. Larger and longer studies are needed to further clarify risks of rejection and adverse effect profiles.

2013 College of Diplomates of the American Board of Pediatric Dentistry Annual Meeting: pediatric cardiology: an overview

Congenital heart defects can be classified as those characterized by a left to right shunt, a right to left shunt, obstruction to flow from the heart, or abnormalcies of myocardial contraction and relaxation. Left to right shunts include atrial and ventricular septal defects, and patent ductus arteriosus. Right to left shunts include transposition of the great arteries, tetralogy of Fallot, tricuspid atresia among others. These defects result in cyanosis. Lesions causing obstruction to blood flow from the heart include aortic and pulmonary valve stenosis and coarctation of the aorta. Disorders of myocardial contraction and relation include hypertrophic, dilated, and restrictive cardiomyopathies. In addition, the author will discuss innocent heart murmur and Kawasaki’s disease.

Posterior reversible encephalopathy syndrome and hemorrhage associated with tacrolimus in a pediatric heart transplantation recipient

Posterior reversible encephalopathy syndrome (PRES) is a disorder characterized by gray and white matter abnormalities in the temporal, parietal, and occipital lobes of the brain. Its etiology has been attributed to renal failure, immunosuppressive drugs such as cyclosporine and tacrolimus, and other potential entities leading to acute hypertension. Clinical findings include headaches, altered mental status, seizures, visual changes, and focal neurologic deficits. We report the case of a child who developed PRES with intracerebral and subarachnoid hemorrhages associated with tacrolimus exposure 10 days after heart transplantation for restrictive cardiomyopathy. The patient initially presented with complex partial seizures, headache, agitation, and hypertension. Head MRI was suggestive of PRES along with intracerebral and subarachnoid hemorrhages. Tacrolimus was discontinued and blood pressure was controlled. The patient's encephalopathy resolved, but he has had ongoing neurologic symptoms secondary to hemorrhage. Generally, PRES is less common in children than in the adult population and is a rare complication of calcineurin inhibitors (CNI). Presentation with secondary hemorrhage also can occur. In children receiving CNIs presenting with new neurologic symptoms, PRES should be considered as prompt discontinuation of the offending agent can induce resolution of symptoms. Children can develop hemorrhage in the context of PRES, leading to increased morbidity.

A reduced-energy intake, well-balanced diet improves weight control in children with Prader-Willi syndrome

BACKGROUND

Children with Prader-Willi syndrome (PWS) have a predictable pattern of weight gain, with obesity beginning in early childhood and worsening as they get older and hyperphagia increases. Data on the most effective dietary modifications are scant and primarily anecdotal. As part of a longitudinal study investigating the natural history of PWS, we evaluated the effect of a well-balanced, energy-restricted diet on body composition and weight in young children with PWS.

METHODS

Sixty-three children, aged 2-10 years, with genetically proven PWS participated in the present study. These children had measurements of body composition by dual-energy X-ray absorptiometry and resting energy expenditure (REE), as well as a 3-day diet history analysis both before and after intervention. Energy calculations were based on the individual's REE, with the recommendation that the macronutrients of the diet consist of 30% fat, 45% carbohydrates and 25% protein, with at least 20 g of fibre per day.

RESULTS

Thirty-three families adhered to our dietary recommendations for both energy intake and macronutrient distribution. Those 33 children had lower body fat (19.8% versus 41.9%; P < 0.001) and weight management (body mass index SD score 0.3 versus 2.23; P < 0.001) than those whose parents followed the energy intake recommendations but did not alter the macronutrient composition of the diet. Those who followed our recommendations also had a lower respiratory quotient (0.84 versus 0.95; P = 0.002).

CONCLUSIONS

Our recommendation for an energy-restricted diet with a well-balanced macronutrient composition and fibre intake improves both weight and body composition in children with PWS compared to a simple energy-restricted diet.

Protein-losing enteropathy and the Fontan operation

Protein-losing enteropathy (PLE) is a complex disorder characterized by enteric protein loss and often is associated with cardiovascular abnormalities, particularly those with elevated central venous pressure. The Fontan operation is a surgical procedure used to palliate patients with a functional single ventricle. Although the Fontan operation eliminates cyanosis and decreases the workload of the functionally single ventricle, it also elevates central venous pressure. This can result in hepatic and enteric congestion as well as PLE. Despite the universal elevation in central venous pressure, only a fraction of patients who have had a Fontan operation develop PLE. However, PLE is associated with significant morbidity and mortality. Presenting signs and symptoms of PLE include abdominal bloating, diarrhea, edema, pleural effusions, ascites, and failure to thrive. In this review, the authors discuss the diagnosis and prevalence of PLE after the Fontan operation and review currently available therapeutic strategies.

Cardiac transplantation in a pediatric patient with systemic sclerosis

INTRODUCTION

Diffuse cutaneous systemic sclerosis (SSc) is rare in children, but has a poor prognosis when cardiomyopathy is present.

METHODS

We reviewed the case of a 14-year-old female with progressive skin thickening/tightness and dyspnea on exertion who was diagnosed with SSc.

RESULTS

Our patient was found to have severe restrictive cardiomyopathy with poor left ventricular systolic function (ejection fraction = 20%), unresponsive to the immunosuppression used to treat her SSc. There was no evidence of pulmonary fibrosis. The patient underwent orthotopic cardiac transplantation, with improvement in systemic symptoms. Two years after transplantation, she had elevated filling pressures during a surveillance catheterization, with no evidence of cellular rejection or coronary artery vasculopathy. Four months later, she developed severe ventricular dysfunction and dyspnea, despite a negative biopsy and negative C4d immunofluorescence staining. Her immunosuppression was intensified with improvement of cardiac function. Despite this, 1 month later she had sudden pulseless cardiac arrest from which she could not be revived. The family declined an autopsy.

DISCUSSION

We report a 14-year-old female with SSc who had cardiac transplantation. The etiology behind her recurrent restrictive physiology, cardiac dysfunction, and subsequent cardiac arrest remains unclear.

The use of oral budesonide in adolescents and adults with protein-losing enteropathy after the Fontan operation

BACKGROUND

Approximately 5% to 15% of patients develop protein-losing enteropathy (PLE) after the Fontan operation. Oral controlled release (CR) budesonide has been used as a treatment strategy, but its use in the older Fontan population has not been described.

METHODS

Seven patients with refractory PLE after the Fontan operation were started on oral CR-budesonide at 9 mg. After 3 to 9 months, the dose was weaned to 3 mg. Response to treatment was assessed by clinical evaluation, serum albumin levels, and fecal α-1 antitrypsin clearance when available.

RESULTS

Median age at last evaluation was 20 years (range, 16 to 32 years). Six patients had increases in serum albumin levels but only 4 patients had symptomatic improvement. Systemic side effects included: cushingoid features (5), adrenal insufficiency (4), and new-onset type 2 diabetes mellitus (2). One patient had improvement in cushingoid features after weaning CR-budesonide to 3 mg. Older patients (ages 27 to 32 years) had the worst side effect profiles and were the most refractory to treatment. These patients had sonographic evidence of hepatic cirrhosis but normal serum liver function tests. Two deaths occurred: 1 from sepsis 1 month after CR-budesonide initiation and 1 from respiratory arrest 5 months after CR-budesonide discontinuation.

CONCLUSIONS

CR-budesonide can be used to treat PLE in certain patients, but careful assessment of hepatic function should be performed before initiation of therapy as systemic side effects can limit treatment. Normal serum liver function tests do not preclude hepatic dysfunction in the Fontan patient, and it is important to perform radiographic assessments as well.

Epigenetic regulation of pericentromeric heterochromatin during mammalian meiosis

Mammalian meiosis is a process that allows diploid progenitor germ cells to produce haploid gametes after proceeding through 2 rounds of cell divisions. The first division (MI) is unique and results in the separation of homologous chromosomes, while the second division (MII) leads to the separation of sister chromatids similar to a somatic cell division. However, the mechanisms by which meiotic cells regulate their 2 very different cell divisions are not well understood. We postulated a role for epigenetic chromatin modifications in regulating these processes. We found prior to the onset of MI that pericentromeric heterochromatic regions, which are enriched with histone H3K9me2 throughout meiosis, become enriched at late pachytene with H3S10ph and at diplotene with H4K5ace and H4K16ace, but remain underacetylated at other sites examined. RNA polymerase II, which is clearly excluded from pericentromeric heterochromatin at pachytene, becomes exclusively associated with these regions from diplotene to MI. By contrast, pericentromeric heterochromatic regions at MII are not engaged by RNA polymerase II nor enriched with H3S10ph. Furthermore, we found DICER to localize exclusively to pericentromeric heterochromatin at MI, but not MII. These results are significant since they suggest: (1) that distinct chromatin modifications differentiate the 2 meiotic divisions; (2) a role for repetitive DNA elements and RNAi in mammalian meiosis; (3) H3K9me2 is not sufficient to block RNA polymerase II elongation through heterochromatin, and (4) H3S10ph provides a 'binary switch' to activate transcription in heterochromatin.

Pulmonary thromboendarterectomy in adolescents and young adults

OBJECTIVES

Chronic thromboembolic pulmonary hypertension (CTEPH) occurs in patients with recurrent or chronic pulmonary embolism, and is a rare but potentially devastating disease in adolescents and young adults. Pulmonary thromboendarterectomy (PTE) is an important curative therapy for patients with CTEPH. The importance of this treatment may be under-appreciated and under-utilized in adolescents and young adults.

STUDY DESIGN

We performed a chart review of all patients <24 years of age who had PTE performed for CTEPH at our institution from 2003-2009 (seven patients, average age 20.2 +/- 2.5 years, range 17-23 years, average BMI 34 +/- 12 kg/m(2)). All patients had their operations performed by a single surgeon.

RESULTS

There were no deaths. Three of the seven patients were incorrectly diagnosed prior to the diagnosis of CTEPH. Right ventricular systolic pressure decreased from 61.3 +/- 19 mmHg pre-operatively to 31.8 +/- 5 mmHg post-operatively (P = 0.008). All patients reported symptomatic relief, and no patient has had recurrence of CTEPH.

CONCLUSION

Although rare in the young patient, recurrent pulmonary emboli can have devastating consequences. The potentially lethal implications of CTEPH may be under-appreciated in adolescents and young adults. When indicated, PTE is a definitive, curative procedure with low morbidity and mortality.

Novel roles of GATA1 in regulation of angiogenic factor AGGF1 and endothelial cell function

AGGF1 is an angiogenic factor, and its deregulation is associated with a vascular malformation consistent with Klippel-Trenaunay syndrome (KTS). This study defines the molecular mechanism for transcriptional regulation of AGGF1 expression. Transcription of AGGF1 starts at two nearby sites, -367 and -364 bp upstream of the translation start site. Analyses of 5'- and 3'-serial promoter deletions defined the core promoter/regulatory elements, including two repressor sites (from -1971 to -3990 and from -7521 to -8391, respectively) and two activator sites (a GATA1 consensus binding site from -295 to -300 and a second activator site from -129 to -159). Both the GATA1 site and the second activator site are essential for AGGF1 expression. A similar expression profile was found for GATA1 and AGGF1 in cells (including various endothelial cells) and tissues. Electrophoretic mobility shift assay and chromatin immunoprecipitation assays demonstrated that GATA1 was able to bind to the AGGF1 DNA in vitro and in vivo. Overexpression of GATA1 increased expression of AGGF1. We identified one rare polymorphism -294C>T in a sporadic KTS patient, which is located in the GATA1 site, disrupts binding of GATA1 to DNA, and abolishes the GATA1 stimulatory effect on transcription of AGGF1. Knockdown of GATA1 expression by siRNA reduced expression of AGGF1, and resulted in endothelial cell apoptosis and inhibition of endothelial capillary vessel formation and cell migration, which was rescued by purified recombinant human AGGF1 protein. These results demonstrate that GATA1 regulates expression of AGGF1 and reveal a novel role for GATA1 in endothelial cell biology and angiogenesis.

Comparison of the outcome of porcine bioprosthetic versus mechanical prosthetic replacement of the tricuspid valve in the Ebstein anomaly

Our objective was to determine the relative merits of using a bioprosthetic porcine valve (BPV) versus a mechanical valve (MechV) when tricuspid valve (TV) replacement is required in patients with Ebstein anomaly. From 1972 to 2006, 333 patients received a BPV and 45 received a MechV. Patient records were reviewed, vital status ascertained, and all patients not known to be deceased were mailed a medical questionnaire or contacted by telephone. Early mortality was not statistically higher for patients who had a MechV (11%) than for those who had a BPV (5%) inserted in the TV position (p = 0.173). The only independent preoperative predictor of operative mortality was moderate to severe left ventricular dysfunction (odds ratio 3.1, p = 0.03); 20-year survival was better in patients who had a BPV (75%) than for those who had a MechV (43%, p = 0.003). On multivariate analysis, after adjusting for ablation of accessory pathways, sinus rhythm at dismissal, and concomitant repair of pulmonary valve stenosis, a BPV remained a predictor of late survival (hazard ratio 0.42, p = 0.004). Survival free of reoperation on the TV at 20 years postoperatively was similar for patients who had a MechV (49%) compared with those who had a BPV (42%) inserted (p = 0.941). A greater percentage of patients who had a MechV reported endocarditis (12% vs 2%), bleeding requiring hospitalization (6% vs 3%), and thrombosis (12% vs 6%); however, none of these differences were statistically significant. In conclusion, a BPV in the tricuspid position was an independent predictor of improved survival. This may be related to the higher incidence of bleeding and thrombotic complications in the patients with MechVs or may be related to differences between the 2 groups. A BPV may offer superior late survival when compared with a MechV when TV replacement is required in patients with Ebstein anomaly, but patient selection must be individualized.

Effect of operation for Ebstein anomaly on left ventricular function

Our objective was to examine the outcomes of patients with left ventricular (LV) dysfunction who underwent operation for Ebstein anomaly. From April 1, 1972 to January 1, 2006, 539 patients with Ebstein anomaly underwent operation at Mayo Clinic. LV function was determined by echocardiography. Of the 495 patients with preoperative echocardiographic assessment of LV function, 50 had moderate or severe LV systolic dysfunction. In patients with LV dysfunction, the tricuspid valve (TV) was repaired in 12 patients and replaced in 36 patients; 1 patient had a 1.5 ventricle repair, and 1 patient had cardiac transplantation. There were 5 early deaths (10%). LV function improved in all but 4 patients after operation. In no patient did LV function worsen after operation. The 1-, 5-, and 10-year survival was 86%, 77%, and 67%, respectively. On univariate analysis, absence of sinus rhythm at dismissal (p = 0.003) was associated with greater overall mortality. For the entire cohort of 539 patients, LV dysfunction was independently predictive of late mortality (hazard ratio 3.76, p <0.001). At late follow-up (mean 6.9 years), 86% of patients were in New York Heart Association class I or II. In conclusion, LV systolic dysfunction occurs infrequently in patients with Ebstein anomaly and is a risk factor for increased late mortality. Although early mortality is greater in patients with LV dysfunction, the late results are favorable. Decreasing LV function should be an indication to promptly restore TV competence rather than a contraindication to TV operation.

Functional status after operation for Ebstein anomaly: the Mayo Clinic experience

OBJECTIVES

The objective of this study was to review the long-term functional outcome of patients with Ebstein anomaly who had cardiac operation at our institution.

BACKGROUND

Ebstein anomaly is a spectrum of tricuspid valvular and right ventricular dysplasia. Many patients will require operation in an attempt to improve quality of life.

METHODS

From April 1, 1972, to January 1, 2006, 539 patients with Ebstein anomaly underwent 604 cardiac operations at the Mayo Clinic in Rochester, Minnesota. Patient records were reviewed, and all patients known to still be alive were mailed a medical questionnaire or contacted by telephone.

RESULTS

At the initial operation at our institution, the mean age of the patients was 24 years (range 8 days to 79 years) and 53% were female patients. Survival at 5, 10, 15, and 20 years was 94%, 90%, 86%, and 76%, respectively. Survival free of late reoperation was 86%, 74%, 62%, and 46% at 5, 10, 15, and 20 years, respectively. Surveys were returned by 285 of 448 (64%) patients known to be alive at the time of this study. Two hundred thirty-seven (83%) patients were in New York Heart Association functional class I or II, and 34% were taking no cardiac medication. One hundred three patients (36%) reported an incident of atrial fibrillation or flutter, 5 patients (2%) reported having had endocarditis, and 1 patient (<1%) reported having a stroke. There were 275 pregnancies among 82 women. The recurrence of congenital heart disease was reported in 9 of 232 (3.9%) liveborn children.

CONCLUSIONS

Patients have good long-term survival and functional outcomes after undergoing surgery for Ebstein anomaly. Atrial arrhythmias are common both before and after surgery. Many patients have had one or more successful pregnancies with a low-recurrence risk of congenital heart disease.

Cardiorespiratory function after operation for pectus excavatum

OBJECTIVE

We performed a review of current data to determine the effect that operation has on pulmonary function, aerobic capacity, and stroke volume in patients with pectus excavatum.

STUDY DESIGN

Two reviewers independently assessed clinical trials and collected data on interventions and outcomes. To qualify for inclusion, a study had to include preoperative and postoperative assessment, provide outcomes in either a published percentile or qualified matched control form to control for interval growth, and include only original patient groups.

RESULTS

Postoperative total lung capacity for patients who had Ravitch repair was significantly lower (SMD, 0.71 [CI -1.06, -0.36]; I(2) = 19.6%) than preoperative. Based on 2 studies after removal of the Nuss bar, FEV(1) was significantly increased from preoperative values (SMD, 0.39 [CI, 0.03, 0.74]; I(2) = 0%). Stroke volume increased after surgery (SMD, 0.40 [CI, 0.10, 0.70]; I(2) = 0%) after Ravitch repair. There was a trend toward improved exercise tolerance, but it was not statistically significant.

CONCLUSIONS

Total lung capacity was decreased after Ravitch repair, and FEV(1) was increased after Nuss bar removal. Stroke volume may be increased after Ravitch repair. Exercise tolerance was not improved after either type of surgical repair.

Identification of association of common AGGF1 variants with susceptibility for Klippel-Trenaunay syndrome using the structure association program

Klippel-Trenaunay syndrome (KTS) is a severe congenital disorder characterized by capillary malformations, venous malformations or varicose veins, and hypertrophy of the affected tissues. The angiogenic factor gene AGGF1 was previously identified as a candidate susceptibility gene for KTS, but further genetic studies are needed to firmly establish the genetic relationship between AGGF1 and KTS. We analyzed HapMap data and identified two tagSNPs, rs13155212 and rs7704267 that capture information for all common variants in AGGF1. The two SNPs were genotyped in 173 Caucasian KTS patients and 477 Caucasian non-KTS controls, and both significantly associated with susceptibility for KTS (P= 0.004 and 0.013, respectively). Permutation testing also showed a significant empirical P value for the association (empirical P= 0.006 and 0.015, respectively). To control for potential confounding due to population stratification, the population structure for both cases and controls was characterized by genotyping of 38 ancestry-informative markers (AIMs) and the STRUCTURE program. The association between the AGGF1 SNPs and KTS remained significant after multivariate analysis by incorporating the inferred cluster scores as a covariate or after removal of outlier individuals identified by STRUCTURE. These results suggest that common AGGF1 variants confer risk of KTS.

Altered endothelial function in asymptomatic male adolescents with type 1 diabetes

OBJECTIVE

While adult men and women with diabetes experience similar rates of cardiovascular disease, early microvascular complications show significant gender differences during adolescence. The goal of this study was to determine whether a gender contrast in a preclinical stage of atherosclerosis, or endothelial dysfunction, is present in pediatric diabetic patients.

METHODS

Reactive hyperemia-peripheral arterial tonometry (RH-PAT), a noninvasive method to assess endothelial dysfunction, was used. Measurements were performed at rest and after hyperemia in 20 diabetic subjects and 20 age- and gender-matched nondiabetics, aged 12-16 years. Confounding risk factors for endothelial dysfunction, including smoking, obesity, and hypertension, were excluded.

RESULTS

RH-PAT was lower for male diabetic subjects vs. controls (n = 12, 1.60 +/- 0.32 vs. 1.92 +/- 0.28, P < .001). RH-PAT was similar in female diabetic patients vs. controls. Male and females with type 1 diabetes subjects had equivalent metabolic control (HbA1C 7.48 +/- 1.0 vs. 7.51 +/- 0.9) and lipid profiles. No difference was observed in age, HbA1C, and diabetes duration, between male and female diabetic subjects. However, diabetic female patients had a greater body mass index (24.2 +/- 2.5 vs. 20.6 +/- 2.0, P = .003) and were more mature in pubertal status as compared with diabetic male patients.

CONCLUSION

Endothelial dysfunction was present in adolescent male diabetic subjects as measured using RH-PAT. Considering that endothelial dysfunction is reversible, early detection of this process may have therapeutic and prognostic implications in this young age group.

Hysteroscopic sterilization in women with severe cardiac disease: experience at a tertiary center

OBJECTIVE

To determine the feasibility and effectiveness of hysteroscopic sterilization as a minimally invasive sterilization method for women with high-risk cardiac disease.

PARTICIPANTS AND METHODS

In a retrospective cohort study, 18 women with high-risk cardiac conditions that strictly contraindicated pregnancy were compared with a reference cohort of 157 women without cardiac disease. All underwent microinsert hysteroscopic sterilization at Mayo Clinic from January 2003 through February 2007. End points included successful placement, fallopian tube patency determined by hysterosalpingogram 3 months after the procedure, and pregnancy status.

RESULTS

Women in the cardiac cohort were younger than those in the reference cohort (median age, 25 vs 39 years; P<.001), had lower parity (median, 0 vs 2; P<.001), and had a higher proportion of patients categorized as American Society of Anesthesiologists' physical status 3 (severe systemic disease) and physical status 4 (systemic disease that is a constant threat to life) (83% vs 6%; P<.001). No significant differences were noted for use of general anesthesia (17% vs 27%; P=.41), successful bilateral device placement (100% vs 95%; P>.99), postoperative pain score (median, 0 for both groups; P=.87), or length of hospitalization (median, 6 vs 6 hours; P=.63). No intraoperative complications occurred. Follow-up hysterosalpingography showed high tubal occlusion rates in both cohorts (100% cardiac; 98% reference; P>.99). No pregnancies occurred during a median follow-up period of 20 months (interquartile range, 8-33 months).

CONCLUSION

For women with cardiac disease and strict contraindications for pregnancy, microinsert hysteroscopic sterilization provided minimally invasive, permanent, and reliable contraception.

Long-term results of the Fontan operation

Modifications of the Fontan operation can afford excellent palliation for many patients with a variety of forms of single ventricle. In properly selected patients who are good candidates, early and late survival can be as high as 95-97%. However, mortality is considerably higher for patients with risk factors for poor outcome. For high-risk patients, inclusion of a fenestration may reduce morbidity and mortality. Important long-term undesirable events include the ongoing risk of death, arrhythmias, protein-losing enteropathy, and cardiac failure. The key to excellent long-term outcome is proper selection of patients for the operation.