A prospective, longitudinal study of central venous catheter-related deep venous thrombosis in boys with hemophilia.

BACKGROUND: Central venous catheters (CVCs) are often inserted into boys with hemophilia to secure venous access for factor prophylaxis and immune tolerance induction therapy. Complications associated with CVCs include catheter-related infections, local hemorrhage, and mechanical failure. Less frequently reported is CVC-related deep venous thrombosis (DVT). We conducted a prospective study to determine the frequency and outcome of this complication. METHODS: All boys (n = 16) with congenital hemophilia A or B with a CVC in place who were registered in the pediatric comprehensive care program at the Hospital for Sick Children, Toronto, were included in the study. They were prospectively assessed by imaging studies and clinical examinations for CVC-related DVT at two time-points, 2 years apart. Each boy was evaluated for inherited hypercoagulability. RESULTS: Eleven (69%) of the 16 boys had radiological evidence of DVT at the first evaluation and 13/16 (81%) at the second evaluation. In two boys there was improvement in the venogram findings at the second evaluation. None of the CVC-related DVTs completely resolved. Median age at the time of initial insertion of a CVC was 1.0 years (range 0.02-6.7 years). Median duration of CVC placement was 6.4 years (range 3.3-15.5 years). Only 4/13 boys with DVTs had clinical evidence of upper venous system obstruction. Only one boy, who did not develop a DVT, had a low protein C level. CONCLUSIONS: CVC-related DVTs occur in the majority of boys with hemophilia who have CVCs inserted for a prolonged period of time. Annual screening with imaging is recommended for boys with CVCs in place for >/= 3 years. Consideration should be given to removing CVCs as soon as peripheral venous access is feasible.

Natural history of arterial and venous thrombosis in children treated with low molecular weight heparin: a longitudinal study by ultrasound.

Low molecular weight heparin (LMWH) is efficacious in preventing recurrent thromboembolic events (TEs) in children. The efficacy of LMWH in resolving thrombus in children is, however, unknown and may differ from what has been observed in adults due to known differences in the hemostatic system. We reviewed the ultrasound (US) scanning reports of children treated with LMWH in order to determine the rate and predictors of thrombus resolution. Of 245 children consecutively treated for a non-cerebral TE with enoxaparin (Lovenox, Aventis Pharma Inc., QC, Canada) for at least 5 consecutive days, 190 (78%) had serial ultrasound available for analysis. The mean follow-up time was 7 months (median 3 months, range 3 days to 6.6 years). The rate of complete thrombus resolution was 101/190 (53%, 95% confidence interval 46.2-60.2%). On univariate analysis, arterial and non-occlusive thrombus had an increased rate of resolution when compared with venous and occlusive thrombus. Age at time of TE (neonates vs. non-neonates), location of TE, initial treatment (unfractionated heparin vs. LMWH) and dose of enoxaparin were not related to outcome. On multivariate analysis, type of vessel (vein vs. artery) and occlusion (occlusive vs. non-occlusive thrombus) independently predicted outcome. In children, the rate of complete thrombus resolution is similar to the rate in adults. The clinical significance of residual abnormal vessels, specifically to the occurrence of post-thrombotic syndrome and for the diagnosis of recurrence, needs to be explored in prospective studies.

Early treatment improves growth and biochemical and radiographic outcome in X-linked hypophosphatemic rickets.

X-Linked hypophosphatemic rickets (XLH) is characterized by hypophosphatemia, rickets, and impaired growth. Despite oral phosphate and 1,25-dihydroxyvitamin D(3) treatment, many patients have suboptimal growth and bone healing. The aim of this study was to assess whether age at treatment onset impacts the outcome. Growth data, biochemistry, and radiographs of 19 well-controlled patients with XLH were analyzed retrospectively. Patients were divided into two groups based on the age at treatment onset (group 1, <1.0 yr; group 2, >or=1.0 yr). The median height z-score was higher in group 1 (n = 8) than in group 2 (n = 11) at treatment onset [-0.4 SD score (SDS) vs. -1.7 SDS; P = 0.001], at the end of the first treatment year (-0.7 SDS vs. -1.8 SDS; P = 0.009), throughout childhood (P > 0.05) and until predicted adult height (-0.2 SDS vs. -1.2 SDS; P = 0.06). The degree of hypophosphatemia was similar in both groups, but serum alkaline phosphatase remained higher in group 2 throughout childhood. Radiographic signs of rickets were more marked in group 2, but even patients with early treatment developed significant skeletal changes of rickets. These data suggest that treatment commenced in early infancy results in improved outcome in patients with XLH, but does not completely normalize skeletal development.

Correlation between radiographic transition zone and level of aganglionosis in Hirschsprung's disease: Implications for surgical approach.

BACKGROUND/PURPOSE: The anticipated level of aganglionosis can influence the surgical approach to Hirschsprung's disease. The aim of this study was to determine the accuracy of the contrast enema in predicting this level. METHODS: Over a 6-year period (1995 through 2000), 88 patients with Hirschsprung's disease underwent surgical correction. Preoperative contrast enema findings were available for 75 of these patients and were compared with operative and pathology reports. Data were analyzed by chi(2). RESULTS: The contrast enema showed a transition zone suggestive of Hirschsprung's disease in 67 of 75 patients (89%). In 59 of 67 (88%), the pathologic and radiographic transition zones were concordant. Seven of the 8 patients with discordant studies had total colonic (n = 5) or long-segment (n = 2) disease. Contrast enema correctly predicted the level of aganglionosis in 55 of 62 (89%) patients with rectosigmoid disease but only 4 of 13 (31%) of those with long-segment or total colonic disease (P <.01). Of the patients with a radiographic transition zone in the rectosigmoid, 54 of 60 (90%) had a matching level of aganglionosis. CONCLUSIONS: In rectosigmoid Hirschsprung's disease, the location of the radiographic transition zone correlates accurately with the level of aganglionosis in 90% of cases. However, the small incidence of discordance between anticipated level of aganglionosis and operative findings should be recognized, particularly when planning a one-stage transanal pull-through.

Pediatric appendicitis in "real-time": the value of sonography in diagnosis and treatment.

OBJECTIVES: To determine the accuracy of sonography in the diagnosis of clinically equivocal appendicitis, and to identify the factors leading to an inaccurate ultrasound diagnosis. The impact of sonographic findings on clinical management and outcome of children with appendicitis is examined. METHODS: We performed a retrospective review of 317 children who attended the emergency department (ED) of a children's hospital for acute abdominal pain for which acute appendicitis was the main differential diagnosis. They had ultrasound because the diagnosis was uncertain clinically. RESULTS: The positive predictive value of ultrasound for appendicitis was 0.92, and the negative predictive value was 0.88. The sensitivity and specificity could not be determined because there were 43 patients with equivocal ultrasound results. The pitfalls hindering the accuracy of ultrasound diagnosis included a high incidence of perforated appendicitis at presentation, the retrocecal appendix, and other technical factors such as abdominal guarding, excessive bowel gas, obesity, inadequate bladder filling, and the uncooperative patient. When ultrasound findings were combined with clinical judgment in clinical management, there were only five cases of non-therapeutic laparotomy and eight cases of delayed surgery due to missed diagnosis in our cohort. CONCLUSIONS: Ultrasound is a useful for the evaluation of acute abdominal pain in children. However, in the setting of a pediatric hospital ED, the accuracy of ultrasound and its ability to improve early hospital triage may be reduced. Repeated clinical review is still essential and in selected cases, appendiceal CT scan may be required to guide therapeutic decision making.

Pitfalls in the sonographic diagnosis of juxtadiaphragmatic pulmonary sequestrations.

BACKGROUND: Sonographic evaluation of juxtadiaphragmatic lesions is frequently the initial imaging modality of choice in the pediatric population. The increasing sophistication of sonographic and Doppler technologies has led to the suggestion in the literature that lesions suspected of being juxtadiaphragmatic pulmonary sequestrations can be confidently imaged by ultrasound examination alone. OBJECTIVE: To present four cases which raise concern over the accuracy of sonographic examination of these lesions. MATERIALS AND METHODS: We present four such lesions for which an initial erroneous diagnosis of pulmonary sequestration was suggested on an initial ultrasound examination. CONCLUSION: The potential of a missed diagnosis of neuroblastoma has led us to propose that any lesion not demonstrating unequivocal sonographic findings of pulmonary sequestration should undergo further investigation and, if necessary, tissue sampling or excision.

Fine-needle aspiration biopsy in the management of thyroid nodules in children and adolescents.

We reviewed the utility of fine-needle aspiration biopsy (FNAB) in the management of thyroid nodules in 41 children and adolescents (35 girls; mean age, 13.3 years). Cytologic findings were benign in 30, malignant in 2, suspicious in 6, and insufficient in 3. The malignancy rate was 5%, with no false-negative results. Diagnostic accuracy for FNAB was 87% and inter-observer reliability was 88%. FNAB is safe and highly accurate in the evaluation of thyroid nodules in childhood.

Breast US in children and adolescents.

Ultrasonography (US) is of value in the evaluation and characterization of breast masses in children. Most masses represent either normal breast tissue, cysts, or fibroadenomas. Premature thelarche may be unilateral, and normal breast tissue is found at US. Cysts are commonly retroareolar; when they become infected, they appear sonographically as a complex mass. Fibroadenoma is the most frequent breast tumor in adolescent girls, and it is usually solitary, homogeneous, and hypoechoic. Malignant breast lesions are very rare in children; most are due to metastatic disease secondary to rhabdomyosarcoma, leukemia, lymphoma, and neuroblastoma, and their US appearance is nonspecific. Gynecomastia in boys can be mimicked by general obesity and pectoral hypertrophy; US is helpful in the diagnosis, especially when gynecomastia is asymmetric. Most breast lesions in children and adolescents are benign, and surgery should be avoided to prevent later deformity. US is the ideal imaging modality to evaluate breast lesions and may be used to guide a fine-needle aspiration biopsy. Color Doppler US evaluation is helpful; cysts are avascular, fibroadenomas may be avascular or hypovascular, and abscesses show peripheral increased flow. Bloody nipple discharge is more common in prepubertal patients, may occur in infants, and may be secondary to mammary ductal ectasia. Discharge commonly resolves spontaneously, and findings at US are frequently normal.

Carotid artery distensibility and cardiac function in adolescents with type 1 diabetes.

OBJECTIVE: To determine the presence and correlates of early heart and blood vessel dysfunction in adolescents with type 1 diabetes mellitus (DM) of relatively short duration. STUDY DESIGN: A total of 33 patients with DM (20 male, mean age 15.8 +/- 1.3 years, mean DM duration 9.3 +/- 3.9 years) and 16 healthy subjects in a nondiabetic control group (7 male, mean age 17.4 +/- 1.7 years) underwent (1) ultrasonography of the right carotid artery to assess distensibility, compliance, and intimal-medial thickness (IMT), (2) echocardiographic assessment of systolic and diastolic ventricular function, (3) lipid profile and hemoglobin A(1c), and (4) overnight timed urine collections for albumin excretion rate. RESULTS: Ultrasonography showed significantly lower carotid artery distensibility in the DM group (38.5 +/- 8.2 x 10(-3) vs 46.5 +/- 11.7 x 10(-3)/kPa, P =.01) but no difference in compliance (14.0 +/- 3.4 x 10(-7) vs 15.8 +/- 2.9 x 10(-7)m(2)/kPa, P =.08) or IMT (0.061 +/- 0.013 vs 0.060 +/- 0.014 cm, P =.77). Left ventricular (LV) end-diastolic diameter, LV posterior wall thickness, end-systolic wall stress, shortening fraction, ejection fraction, LV mass, and diastolic function were similar in both groups. Total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, and blood pressure were also similar. The median albumin excretion rate was 4.8 microg/min in the DM group (range 1.1 to 19.2) and 3.0 microg/min in the control group (range 1.4 to 5.8) (P =.03). Hemoglobin A(1c) correlated inversely with both distensibility (r = -.43, P =.02) and compliance (r = -.39, P =.032). CONCLUSIONS: This study indicates that early changes in macrovascular function, namely lower carotid artery distensibility, may precede abnormalities in cardiac function or in arterial IMT in adolescents with short duration type 1 DM. It also supports a relationship between hyperglycemia and carotid artery dysfunction.

The impact of imaging in the management of intussusception owing to pathologic lead points in children. A review of 43 cases.

OBJECTIVE: To review the imaging appearances, management and outcome of a large number of children with intussusception owing to pathologic lead points (PLP) in an attempt to define the role of various imaging modalities in this clinical setting. MATERIALS AND METHODS: Review of the records and imaging studies of 43 children with intussusception due to PLP diagnosed between 1986 and 1999. RESULTS: The commonest PLP found were Meckel diverticulum, polyps, Henoch-Schonlein purpura and cystic fibrosis. PLP were depicted on sonography in 23 (66%) of 35 patients, on computed tomography in 5 (71%) of 7, on air enema in 3 (11%) of 28, and on barium enema in 6 (40%) of 15. Air enema successfully reduced 60% of the intussusceptions. Nine children had recurrent intussusceptions. CONCLUSION: Sonography depicted two-thirds of PLP and provided a specific diagnosis in nearly one-third of our series. Our review does not provide sufficient data on how to continue the investigation of those patients in whom sonography does not depict a PLP but in whom there is a high index of suspicion for its presence. It remains a diagnostic challenge as to how to search for PLP in these patients, and other imaging modalities have to be requested according to each particular case.

Severe aortic thrombosis in the neonate--successful treatment with low-molecular-weight heparin: two case reports and review of the literature.

Small- to moderate-sized aortic thrombi in the sick newborn are frequently demonstrated, however, severe aortic thrombosis is rarely encountered. We report two newborn infants presenting with signs of decreased lower limb perfusion shortly after birth. An occlusive infrarenal aortic thrombus was demonstrated in both infants by ultrasound. No predisposing condition for thrombosis could be found in the first infant; in the second, an umbilical arterial catheter was the likely cause. The infants were successfully treated with low-molecular-weight heparin. In both infants resolution of the thrombus was observed by ultrasound. No complications of treatment were encountered. The clinical spectrum of neonatal aortic thrombosis and treatment options are reviewed.

Multiple unilateral renal cysts in two children.

We report two children who presented with multiple renal cysts involving only one kidney and in whom there was no family history of renal disease and who did not have syndromes known to be associated with renal cystic disease. This unilateral involvement may represent a distinct entity, which has only been previously described in three cases; however, long-term follow-up will be needed to confirm this hypothesis. We illustrate the sonographic and computed tomographic findings, and the differential diagnosis is discussed.

Spontaneous reduction of intussusception: clinical spectrum, management and outcome.

BACKGROUND: To analyze the spectrum of clinical features, management and outcome of children with documented spontaneous reduction of intussusception (SROI). MATERIALS AND METHODS: Review of records of 50 children (33 boys, 17 girls; age range 11 days-15 years; mean age 4 years) with documented SROI, in whom intussusception was initially diagnosed by sonography (US) in 44, air enema in 2, and computed tomography in 4, in the 6-year period 1992-1998. RESULTS: Symptoms suggestive of intussusception were present in 21 (3 of whom had Henoch-Schönlein purpura and 4 had previous ileocolic intussusception reduced by air enema). Intussusception was an incidental finding in the other 29, in 28 of whom the finding was in the small bowel. Intussusception was limited to the small bowel in 43 and was ileocolic in 7. SROI was usually documented on US. Laparotomy performed in only 4 showed no evidence of intussusception or pathologic lead point. Outcome in all patients was favorable. CONCLUSIONS: SROI may present in symptomatic or asymptomatic children and occurs more commonly than previously reported. These intussusceptions are usually short-segment, small-bowel intussusceptions with no recognizable lead point. In asymptomatic patients, conservative observation is warranted. Intervention should be dictated by the clinical findings in symptomatic patients.

Gastric perforation attributable to liquid nitrogen ingestion.

Despite the widespread use of liquid nitrogen in medicine and industry, there are only a few reports of injuries associated with its use. We report a case of a 13-year-old boy who developed gastric perforation after liquid nitrogen ingestion. This is a previously unreported complication.

Malignant peripheral nerve-sheath tumor arising in a previously irradiated neuroblastoma: report of 2 cases and a review of the literature.

BACKGROUND: Only ten cases of the rare occurrence of a malignant peripheral nerve-sheath tumor (MPNST) arising in a ganglioneuroma either de novo or at a site of previous irradiation have been reported. PATIENTS AND METHODS: We present two children who at the age of 19 months and 6 months were diagnosed with a cervicothoracic ganglioneuroblastoma and a retroperitoneal neuroblastoma, respectively. They both received radiation therapy as part of the treatment of their disease. RESULTS: Following a 12-year interval, MPNST arose inside a benign ganglioneuroma in both patients. We illustrate the imaging findings in these two cases and review the cases reported in the literature to increase awareness of this association among radiologists.