Gitelman's syndrome: a rare presentation mimicking cauda equina syndrome.

We describe a case of bilateral weakness of the lower limbs, sensory disturbance and intermittent urinary incontinence, secondary to untreated Gitelman's syndrome, in a 42-year-old female who was referred with presumed cauda equina syndrome. On examination, the power of both legs was uniformly reduced, and the perianal and lower-limb sensation was altered. However, MRI of the lumbar spine was normal. Measurements of serum and urinary potassium were low and blood gas analysis revealed metabolic alkalosis. Her symptoms resolved following potassium replacement. We emphasise the importance of measurement of the plasma and urinary levels of electrolytes in the investigation of patients with paralysis of the lower limbs and suggest that they, together with blood gas analysis, allow the exclusion of unusual causes of muscle weakness resulting from metabolic disorders such as metabolic alkalosis.

Vascular endothelial growth factor delays onset of failure in pressure-overload hypertrophy through matrix metalloproteinase activation and angiogenesis.

OBJECTIVE: Pressure-overload hypertrophy is associated with decreased capillary density in myocardium resulting in impaired substrate delivery. Treatment of hypertrophied hearts with vascular endothelial growth factor (VEGF) induces angiogenesis. Since angiogenesis is associated with extracellular matrix degradation, we sought to determine whether VEGF induced angiogenesis in hypertrophy required matrix metalloproteinases (MMP) activation. METHODS: Newborn rabbits underwent aortic banding. Progression of hypertrophy (mass-to-volume (M/V) ratio) and mid-wall contractility index was monitored by echocardiography. At 4 and 6 weeks, VEGF (2 microg/kg), vehicle or VEGF combined with GM6001 (5 mg/kg), a MMP inhibitor, was administered intrapericardially. CD-31 (indicator of angiogenesis), MMP-2, MT1-MMP and TIMPs (endogenous MMP inhibitors) expression were measured by immunoblotting. MMP-2 activity was determined by gelatin zymography. RESULTS: Untreated hypertrophied hearts progressed to ventricular dilatation at 7 wks (M/V ratio: 0.75 +/- 0.07), but compensatory hypertrophy was maintained with VEGF (0.91 +/- 0.07; p < 0.05). LV contractility declined in untreated hearts from -0.41 +/- 0.9 (5 wks) to -0.73 +/- 0.5 (7 wks; p < 0.05) but remained normal with VEGF (+1.61 +/- 0.6 vs. +0.47 +/- 0.2). MMP-2 expression and activity were significantly elevated in VEGF treated hypertrophied hearts (p < 0.05) and were blocked by concomitant administration of GM6001. VEGF induced neovascularization was inhibited by addition of GM6001. MT1-MMP showed a trend to higher levels in VEGF treated hearts. TIMPs were unchanged in all three groups. CONCLUSIONS: Exogenous VEGF and resultant MMP-2 activation leads to increased capillary formation in severe hypertrophy, preventing progression to ventricular dilation and dysfunction. VEGF and the associated MMP-2 activation play an important and potentially therapeutic role in vascular remodeling of hypertrophied hearts.

Epidemiology of cystic fibrosis-related diabetes.

OBJECTIVES: Cystic fibrosis-related diabetes (CFRD) has emerged as an important complication of CF. To better understand who is at risk of developing CFRD, to gain insight into the impact of CFRD on pulmonary and nutritional status, and to assess the association of CFRD with various practice patterns and comorbid conditions, we characterized the Epidemiologic Study of Cystic Fibrosis (ESCF) patient population. STUDY DESIGN: Analyses were performed on the 8247 adolescents and adults who were evaluated at one of 204 participating sites during 1998. CFRD was defined as the use of insulin or an oral hypoglycemic agent at any time during the year. RESULTS: Previously reported risk factors for CFRD including age, gender (female), and pancreatic insufficiency were confirmed in this study. Patients with CFRD had more severe pulmonary disease, more frequent pulmonary exacerbations, and poorer nutritional status as compared with those without diabetes. CFRD also was associated with liver disease. CONCLUSIONS: CFRD is a common complication in adolescents and adults that is associated with more severe disease.

Inhibition of tumor necrosis factor-alpha improves postischemic recovery of hypertrophied hearts.

BACKGROUND: Tumor necrosis factor (TNF)-alpha has been implicated in the pathogenesis of heart failure and ischemia-reperfusion injury. Effects of TNF-alpha are initiated by membrane receptors coupled to sphingomyelinase signaling and include altered metabolism and calcium cycling, contractile dysfunction, and cell death. We postulate that pressure-overload hypertrophy results in increased myocardial TNF-alpha expression and that it contributes to decreased contractility in hypertrophied infant hearts subjected to ischemia-reperfusion. METHODS AND RESULTS: Neonatal rabbits underwent aortic banding to induce LV hypertrophy. Myocardial TNF-alpha protein expression increased progressively with LV hypertrophy. Serum TNF-alpha was detected only after the onset of heart failure. Before onset of ventricular dilatation and heart failure (determined by serial echocardiograms), hearts from aortic banded and age-matched control rabbits were perfused in the Langendorff mode and subjected to 45 minutes of ischemia and 30 minutes of reperfusion. Postischemic recovery was impaired in hypertrophied hearts, but addition of neutralizing anti-rabbit TNF-alpha antibody to cardioplegia and perfusate solutions restored postischemic function. This effect was mimicked by treatment with the ceramidase inhibitor N-oleoyl ethanolamine. TNF-alpha inhibition also was associated with faster postischemic recovery of phosphocreatine, ATP, and pH as assessed by (31)P nuclear magnetic resonance spectroscopy. Intracellular calcium handling, measured by Rhod 2 spectrofluorometry, demonstrated lower diastolic calcium levels and higher systolic calcium transients in anti-TNF-alpha treated hearts. CONCLUSIONS: TNF-alpha is expressed in myocardium during compensated pressure-overload hypertrophy and contributes to postischemic myocardial dysfunction. Inhibition of TNF-alpha signaling significantly improves postischemic contractile function, myocardial energetics, and intracellular calcium handling.

Valve-sparing operation for balloon-induced aortic regurgitation in congenital aortic stenosis.

OBJECTIVE: Aortic regurgitation after balloon dilation of congenital aortic stenosis may be treated with valve repair as an alternative to replacement. METHODS: Charts and echocardiograms of all patients undergoing aortic valve operations after balloon dilation of congenital aortic stenosis at our institution between January 1988 and December 1999 were reviewed. RESULTS: Twenty-one patients underwent valvuloplasty for predominant aortic regurgitation 9 months to 15 years (mean, 6.1 years) after balloon dilation. The mean +/- SD age at the time of the operation was 11 +/- 7 years. Aortic regurgitation was caused by a combination of commissural avulsion (10), cusp dehiscence with retraction (9), cusp tear (5), central incompetence (2), perforated cusp (1), or cusp adhesion to the aortic wall (1). Repair techniques included commissural reconstruction with a pericardial patch (8), pericardial patch cusp augmentation (6), primary suture repair (6), raphae release and debridement (4), commissurotomy (4), commissural resuspension with sutures (3), and cusp release (1). There were no deaths. At a mean follow-up of 30.1 months (range, 9 months-8 years), all patients were asymptomatic, and the grade of aortic regurgitation had been significantly reduced (P <.001). Left ventricular end-diastolic dimension z scores and proximal regurgitant jet/aortic anulus diameter ratios were significantly reduced (P <.001) and remained so over time. Freedom from reoperation for late failure was 100%, and overall freedom from reintervention was 80% at 3 years. CONCLUSION: Aortic valve repair for balloon-induced aortic regurgitation is reproducible and durable at medium-term follow-up.

Surgical outcome of double-outlet right ventricle with subpulmonary VSD.

BACKGROUND: Optimal management of double-outlet right ventricle with subpulmonary ventricular septal defect remains controversial. We reviewed our 7-year experience with patients who had this anatomic configuration. METHODS: Between January 1992 and January 1999, 20 patients underwent an arterial switch operation (ASO group), and 12 underwent a bidirectional Glenn procedure followed by a modified Fontan in 10 (Glenn/Fontan). Mean follow-up was 23 +/- 18 months. RESULTS: An initial palliative operation was done in 19 patients (9 in the ASO group, 10 in the Glenn/Fontan group). There were no deaths in the Glenn/Fontan group. Four patients in the ASO group died within 33 days postoperatively. Two of them had a single coronary artery, 1 had a straddling mitral valve, 1 had a hypoplastic aortic arch, and 1 had multiple ventricular septal defects. Three patients had reoperation for subaortic stenosis (n = 2) or pulmonary stenosis (n = 1) after the ASO. Four patients (3 in the ASO group, 1 in the Glenn/Fontan) required a pacemaker for postoperative complete atrioventricular block. Actuarial survival at 5 years for the entire group was 87% (70% confidence interval, 81% to 93%). CONCLUSIONS: The ASO remains our preferred treatment for infants with double-outlet right ventricle and subpulmonary ventricular septal defect. However, associated anatomic defects are important risk factors.

Congenital supravalvar aortic stenosis: a simple lesion?

The underlying cause of congenital supravalvular aortic stenosis (SVAS) has recently been identified as a loss-of function mutation of the elastin gene on chromosome 7q11.23, resulting in an obstructive arteriopathy of varying severity, which is most prominent at the aortic sinutubular junction. The generalized nature of the disease explains the frequent association with stenoses of systemic and pulmonary arteries. Furthermore, localization of the supravalvular stenosis at the level of the commissures of the aortic valve has important implications for both aortic valve function and coronary circulation. This review summarizes the recent advances with regard to the pathogenesis of SVAS and describes the multitude of clinically relevant pathologic features other that the mere 'supra-aortic' narrowing that have important implications for surgical therapy.

Long-term results of the lateral tunnel Fontan operation.

OBJECTIVES: Completion of a total cavopulmonary anastomosis with an intra-atrial lateral tunnel is known to yield good early and midterm results. In this study, we sought to determine the long-term outcome (10 years) after a lateral tunnel Fontan procedure. METHODS: Between October 1987 and December 1991, 220 patients (aged 11 months to 32 years) with a wide range of underlying diagnoses underwent a fenestrated or nonfenestrated lateral tunnel Fontan procedure at our institution. Current follow-up information was available for 196 patients (94%, mean follow-up = 10.2 +/- 0.6 years). Risk factor analysis included patient-related and procedure-related variables, with death, failure, and bradyarrhythmia or tachyarrhythmia as outcome parameters. RESULTS: There were 12 early deaths (<30 days or hospital death), 7 late deaths, 4 successful takedown operations, and 4 heart transplantations. Kaplan-Meier estimated survival was 93% at 5 years and 91% at 10 years, and freedom from failure was 90% at 5 years and 87% at 10 years. Freedom from new supraventricular tachyarrhythmia was 96% at 5 years and 91% at 10 years; freedom from new bradyarrhythmia was 88% at 5 years and 79% at 10 years. Three patients had evidence of protein-losing enteropathy. Multivariable risk factors for development of supraventricular tachyarrhythmia included heterotaxy syndrome, atrioventricular valve abnormalities, and preoperative bradyarrhythmia. Risk factors for bradyarrhythmia included systemic venous anomalies. The sole risk factor for late failure was a previous coarctation repair. CONCLUSION: The lateral tunnel Fontan procedure results in excellent long-term outcome even when used in patients with diverse anatomic diagnoses. The incidence of atrial tachyarrhythmia is low and mainly depends on the underlying cardiac morphology and preoperative arrhythmia. The good long-term outcome after an intracardiac lateral tunnel Fontan procedure should serve as a basis for comparison with other surgical alternatives.

Patch augmentation of the pulmonary artery with bioabsorbable polymers and autologous cell seeding.

OBJECTIVE: In recent years bioabsorbable synthetic or biologic materials have been used to augment the pulmonary artery or the right ventricular outflow tract. However, each of these polymers has one or more shortcomings. None of these patch materials has been seeded with cells. Thus, we have tested a fast-absorbing biopolymer, poly-4-hydroxybutyric acid, with autologous cell seeding for patch augmentation of the pulmonary artery in a juvenile sheep model. METHODS: Vascular cells were isolated from ovine peripheral veins (n = 6). Bioabsorbable porous poly-4-hydroxybutyric acid patches (porosity > 95%) were seeded on 3 consecutive days with a mixed vascular cell suspension (21.3 +/- 1.3 x 10(6) cells). Forty-five (+/- 2) days after the vessel harvest, 1 unseeded and 6 autologously seeded control patches were implanted into the proximal pulmonary artery. The animals received no postoperative anticoagulation. Follow-up was performed with echocardiography after 1 week and before explantation after 1, 7, and 24 weeks (2 animals each) for the seeded control patches and after 20 weeks for the nonseeded control patch. RESULTS: All animals survived the procedure. Postoperative echocardiography of the seeded patches demonstrated a smooth surface without dilatation or stenosis. Macroscopic appearance showed a smooth internal surface with increasing tissue formation. Histology at 169 days demonstrated a near-complete resorption of the polymer and formation of organized and functional tissue. Biochemical assays revealed increasing cellular and extracellular matrix contents. The control patch showed a slight bulging, indicating a beginning dilatation. CONCLUSION: This experiment showed that poly-4-hydroxybutyric acid is a feasible patch material in the pulmonary circulation.

Surgical management of mitral regurgitation after repair of endocardial cushion defects: early and midterm results.

BACKGROUND: Mitral regurgitation (MR) represents the principal indication for reoperation in patients after repair of atrioventricular septal defects (AVSD). Reports of mitral valvuloplasty (MVP) in such patients are few; the alternative, mitral valve replacement (MVR), necessitates commitment to future valve replacement and long-term anticoagulation. We sought to determine the outcome of those patients who underwent either MVP or MVR between January 1, 1988, and December 31, 1998, for significant MR after repair of AVSD. Furthermore, we sought to identify (a) morphological predictors necessitating MVR, and (b) predictors of future reoperation within the MVP group. METHODS AND RESULTS: Retrospective review of clinical, operative, and echocardiographic data were performed. There were 46 patients identified (37 MVP and 9 MVR). The median age at initial AVSD repair was 0.6 years, and the age at subsequent mitral valve operation was 2.8 years. The early postoperative mortality rate was 2.2%, and survival at 1 and 10 years was 89.9% and 86.6%, respectively. A high rate of complete heart block was noted within the MVR group (37.5%). Freedom from later mitral valve reoperation for both groups was similar. No significant morphological predictors necessitating MVR were found. Predictors of reoperation within the MVP group included the presence of moderate or worse MR in the early postoperative period. In both groups New York Heart Association class, degree of MR, growth, and ventricular volumes improved. CONCLUSIONS: Mitral valve surgery significantly improves clinical status, with a sustained improvement in ventricular chamber size. MR can be successfully managed in patients after repair of AVSD independent of morphological type. Overall survival is acceptable, and further reoperation within the MVP group is influenced by early outcome of repair.

Non-invasive assessment of rejection in pediatric transplant patients: serologic and echocardiographic prediction of biopsy-proven myocardial rejection.

BACKGROUND: Cardiac allograft rejection is a multifocal immune process that is currently assessed using biopsy-guided histologic classification systems (International Society for Heart and Lung Transplantation). Cardiac troponin T and I are established serologic markers of global myocyte damage. The use of load-independent measures of contractility have also been shown to accurately assess the presence of ventricular dysfunction. Little is known about their utility in accurately predicting rejection in the pediatric age group. We undertook the present study to compare rejection grade with echocardiographic and serologic estimates of transplant rejection-related myocardial damage. METHODS: We compared histologic rejection grades (0 to 4) with patient characteristics, echocardiographic measurements, catheterization measurements, and biochemical markers for 86 evaluations in 37 transplant recipients at Children's Hospital. RESULTS: In univariate analyses, biopsy scores correlated (p < 0.05) inversely with left ventricular systolic function (shortening fraction) and contractility (stress velocity index, SVI), and directly with mitral E-wave amplitude. In multivariate analyses, lower contractility and higher mitral E-wave amplitude remained significantly (p < or = 0.01) associated with rejection (SVI, p = 0.002, odds ratio = 0.393; E wave, p = 0.0002, odds ratio = 228). Most rejection episodes were associated with elevation of biochemical markers of myocardial injury. Although troponin I was weakly associated with differences between rejection grades (p = 0.034), troponin T, creatine kinase-MB fraction, and C-reactive protein did not differ with biopsy-rejection scores. Serum markers had a poor predictive capacity for biopsy-detected rejection. Troponin T and I did correlate with increased left ventricular wall thickness and mass. CONCLUSION: Progressively depressed left ventricular contractility and diastolic function are found with worsening pediatric heart transplant rejection-biopsy score; however, sensitive and specific serum markers do not correspond to the degree of active myocardial injury. The use of echocardiographic measures of contractility is associated with a specificity of 91.8% but low sensitivity of 66.7%. Overall we found poor concordance between serum markers and grade of rejection. It is unclear whether myocardial injury as assessed by serum markers, echocardiography, or histologic scoring is more important for assessment of acute rejection or long-term outcome, but it does not appear that serum and tissue markers of rejection can be used interchangeably.

Surgery for bilateral outflow tract obstruction in elastin arteriopathy.

OBJECTIVE: A number of patients with Williams syndrome or other forms of elastin arteriopathy have stenoses of pulmonary arteries in addition to supravalvular aortic stenosis. We sought to investigate the effect of the degree of pulmonary arterial stenosis on the prognosis after an operation for supravalvular aortic stenosis to help define the optimal treatment strategy for patients with severe forms of elastin arteriopathy. METHODS: Between 1960 and 1999, 33 patients underwent operations for supravalvular aortic stenosis while having significant stenoses of the pulmonary arteries. We retrospectively reviewed patient charts, obtained current follow-up information, and determined risk factors for survival and reoperation. RESULTS: Fifteen patients with moderate right-sided obstructions (confirmed by pulmonary artery Z-scores and right ventricular/descending aortic pressure ratio) underwent operations for supravalvular aortic stenosis only. Eighteen patients had more severe right-sided obstructions and underwent surgical relief of pulmonary arterial stenoses or right ventricular outflow tract obstruction in addition to operations for supravalvular aortic stenosis. Eight patients had undergone preoperative balloon dilations of stenotic pulmonary arteries. There were 6 early deaths and 1 late death in our series. Survival at 10 and 20 years was 76% (70% confidence interval, 68%-84%) and freedom from reintervention was 59% (70% confidence interval, 46%-71%) at 10 years and 49% (70% confidence interval, 35%-62%) at 20 years. Multivariate analysis revealed that patients with a right ventricular/descending aortic pressure ratio of 1.0 or more were at higher risk for reintervention but not for death. CONCLUSIONS: Surgical treatment of pulmonary artery obstructions in elastin arteriopathy is palliative but, in conjunction with balloon dilation of peripheral pulmonary arteries, offers good long-term survival to patients with the severest form of elastin arteriopathy.

Impaired glucose transporter activity in pressure-overload hypertrophy is an early indicator of progression to failure.

BACKGROUND: Severe hypertrophy and heart failure are important risk factors in cardiac surgery. Early adaptive changes in hypertrophy include increased ventricular mass-to-cavity volume ratio (M/V ratio) and increased dependence on glucose for energy metabolism. However, glucose uptake is decreased in the late stages of hypertrophy when ventricular dilatation and failure are present. We hypothesized that impaired glucose uptake would be evident early in the progression of hypertrophy and associated with the onset of ventricular dilatation. METHODS AND RESULTS: Ten-day-old rabbits underwent banding of the descending aorta. Development of hypertrophy was followed by transthoracic echocardiography to measure left ventricular M/V ratio. Glucose uptake rate, as determined by (31)P-nuclear magnetic resonance spectroscopy measuring 2-deoxyglucose conversion to 2-deoxyglucose-6-phosphate, was measured in isolated perfused hearts obtained from banded rabbits when M/V ratio had increased by 15% from baseline (compensated hypertrophy) and by 30% from baseline (early-decompensated hypertrophy). In age-matched control animals, the rate of glucose uptake was 0.61+/-0.08 micromol x g of wet weight(-1) x 30 min(-1) (mean+/-SEM). With a 15% M/V ratio increase, glucose uptake rate remained at control levels (0.6+/-0.05 micromol x g of wet weight(-1) x 30 min(-1)), compared with hearts with 30% increased M/V ratios, where glucose uptake was significantly lower (0.42+/-0.05 micromol x g of wet weight(-1) x 30 min(-1); P

Valved homograft conduit repair of the right heart in early infancy.

BACKGROUND: Valved homograft conduit repair in neonates and young infants creates a physiologically normal biventricular circulation, and unlike shunts, avoids surgery on the branch pulmonary. METHODS: Retrospective chart review was used for 84 patients operated on between 1990 and 1995 (mean age 26+/-28 days, mean weight 3.3+/-0.8 kg) undergoing homograft conduit repair in the first 3 months of life. Cases were divided into simple and complex, eg, absent pulmonary valve syndrome or associated interrupted arch. Mean homograft size was 9.0+/-2 mm. RESULTS: Early mortality was 4.7% (simple) and 30% (complex). Mean hospital stay was 18 days. Mean follow-up was 34 months. Thirty-seven (47%) patients underwent conduit replacement. Median time to reoperation was 3.1 years. Mean size of replacement homograft was 17+/-2 mm. There were no deaths at reoperation. Mean hospital stay at conduit change was 6.3 days. Probability of survival at 5 years is 75%. CONCLUSIONS: Biventricular repair employing a conduit can be performed safely in noncomplex anomalies in the first 3 months of life. Time interval until repeat surgery is relatively short but equal or greater than that with most palliative procedures.

Tissue engineering of autologous aorta using a new biodegradable polymer.

BACKGROUND: Ovine pulmonary valve leaflets and pulmonary arteries have been tissue-engineered (TE) from autologous cells and biodegradable polyglycolic acid (PGA)-polyglactin copolymers. Use of this cell-polymer construct in the systemic circulation resulted in aneurysm formation. This study evaluates a TE vascular graft in the systemic circulation which is based on a new copolymer of PGA and polyhydroxyalkanoate (PHA). METHODS: Ovine carotid arteries were harvested, expanded in vitro, and seeded onto 7-mm diameter PHA-PGA tubular scaffolds. The autologous cell-polymer vascular constructs were used to replace 3-4 cm abdominal aortic segments in lambs (group TE, n = 7). In a control group (n = 4), aortic segments were replaced with acellular polymer tubes. Vascular patency was evaluated with echography. All control animals were sacrificed when the grafts became occluded. Animals in TE group were sacrificed at 10 days (n = 1), 3 (n = 3), and 5 months (n = 3). Explanted TE conduits were evaluated for collagen content, deoxyribonucleic acid (DNA) content, structural and ultrastructural examination, mechanical strength, and matrix metalloproteinase (MMP) activity. RESULTS: The 4 control conduits became occluded at 1, 2, 55, and 101 days. All TE grafts remained patent, and no aneurysms developed by the time of sacrifice. There was one mild stenosis at the anastomotic site after 5 months postoperatively. The percent collagen and DNA contents approached the native aorta over time (% collagen = 25.7%+/-3.4 [3 months] vs 99.6%+/-11.7 [5 months], p < 0.05; and % DNA = 30.8%+/-6.0 [3 months] vs 150.5%+/-16.9 [5 months], p < 0.05). Histology demonstrated elastic fibers in the medial layer and endothelial specific von Willebrand factor on the luminal surface. The mechanical strain-stress curve of the TE aorta approached that of the native vessel. A 66 kDa MMP-2 was found in the TE and native aorta but not in control group. CONCLUSIONS: Autologous aortic grafts with biological characteristics resembling the native aorta can be created using TE approach. This may allow the development of "live" vascular grafts.

Development of a double-chambered right ventricle after repair of tetralogy of Fallot.

OBJECTIVES: We sought to determine the frequency, etiology and progressive nature of midcavity obstruction in patients after primary repair of tetralogy of Fallot (TOF). BACKGROUND: Midcavity obstruction (double-chambered right ventricle [DCRV]) represents a significant portion of reoperations in patients who have had TOF repair. This group is still poorly defined. METHODS: A retrospective review of clinical, echocardiographic and catheterization data for all patients with TOF who later underwent reoperation for DCRV was performed. RESULTS: Between 1973 and 1995, 552 children <2 years of age underwent primary TOF repair (median age 6.7 months). Long-term follow-up (median 50 months) was available in 308 children. Of these, 17 children subsequently developed DCRV requiring reoperation. The median age at initial operation was 7.9 months. During a median follow-up interval of 43.2 months, murmur intensity increased in all patients, and the average subpulmonary gradient at catheterization increased from 24+/-10 to 80+/-27 mm Hg in seven children (p = 0.002) and at Doppler echocardiography from 14+/-16 to 89+/-18 mm Hg in five children (p = 0.002). Before reoperation, 6 of the 17 children were symptomatic. During the operation (median age 55.4 months), obstruction was relieved by incision of hypertrophied anomalous muscle bundles in all 17 patients, with prominent fibrosis noted in 8 patients. Excessive septal and parietal hypertrophy was noted in one child. No new transannular patches were required. Recurrent obstruction has reappeared in 3 of these 17 children during follow-up. CONCLUSIONS: DCRV is a medium-term complication of TOF repair in infants, with a minimal incidence of 3.1% (95% CI 1.8% to 4.9%). The condition is progressive and is due to anomalous muscle bundle hypertrophy or fibrosis, or both, which may represent displaced insertion of a moderator band. Further reobstruction does occur; continued careful follow-up is therefore essential.

Intracranial vascular malformations.

Intracranial vascular malformations are nonneoplastic developmental anomalies that present a variety of clinical patterns, ranging from asymptomatic to fatal intracranial hemorrhage. A practicing radiologist can expect to encounter these abnormalities, which include capillary telangiectasias, venous angiomas (also called developmental venous anomalies), cavernous angiomas, and arteriovenous malformations. The imaging findings that characterize these lesions are reviewed in this article, along with their pathological and clinical features.