Els Nijs

Pediatric Vascular Malformations: Pathophysiology, Diagnosis, and the Role of Interventional Radiology

The Mulliken and Glowacki classification (1982) differentiated vascular anomalies into two groups based on their endothelial characteristics: hemangiomas and vascular malformations. Vascular anomalies are localized defects of the vasculature that affect a limited number of vessels in a restricted area of the body. These defects are secondary to errors in vascular morphogenesis. Depending on the type of vessel involved, the vascular malformation group was subdivided into high-flow (such as arteriovenous malformation and arteriovenous fistula) and low-flow lesions (such as venous and lymphatic malformations). Depending on the type of lesion, the location and degree of involvement and the clinical effect, different types of treatment would be required. For the purpose of this review, we concentrate solely on vascular malformations: the clinical features, genetics, diagnosis, and current treatment options.

Percutaneous sclerotherapy in neonatal and infant head and neck lymphatic malformations: a single center experience

PURPOSE To evaluate the clinical outcomes of percutaneous sclerotherapy for congenital head and neck lymphatic malformations in our institution. MATERIALS AND METHODS Over a 7-year period, 17 children (10 M, 7 F) mean age 5.8 months (5 days to 13 months) underwent 49 sclerotherapy procedures for congenital head and neck malformations. The imaging and clinical records were reviewed for each patient. Ten of 17 had macrocystic disease; 7 of 17 had microcystic disease. Imaging response was categorized by volume reductions of 0% to 25%, 25% to 50%, 50% to 75%, or 75% to 100%. A concentration of 10 mg/mL doxycycline was used routinely via catheter in 3 instillations with a dose range of 50 to 500 mg per session as per our standard protocol in 17 of 17 patients. In more recent patients, systemic doxycycline levels were obtained after instillations. Additional treatments included direct injection doxycycline (10/17), instillation of absolute ethanol (7/17) or sodium tetradecyl sulfate (4/17), or a combination of these methods. RESULTS Imaging improvement of ≥ 76% was noted in 11 of 17. Of these, 8 of 11 had macrocystic disease. Four of 17 had 51% to 75% resolution, of which 3/4 were mixed. Two of 17 children had 25% to 50% resolution with a mixed lesion. Seven of 49 peri-procedural complications: hemolytic anemia in 2 infants, hypoglycemic and metabolic acidosis in 3 neonates aged 7 to 10 days, transient hypotension during absolute alcohol instillation in 1 neonate, and self-limiting skin excoriation secondary to peri-catheter leakage of doxycycline in one neonate. Neonates prone to these systemic complications had doxycycline doses of greater than 250 mg and resulted in serum levels of >5 μg/mL but as high as 21 μg/mL. Delayed neural complications occurred in 7 of 49 procedures, Horners syndromes in 4 of 49 procedures, transient left lip weakness in 1 of 49 procedures, right facial nerve palsy in 1 of 49 procedures, and transient left hemidiaphragm paralysis in 1/49 procedures. CONCLUSION Our experience with catheter directed doxycycline sclerotherapy provides excellent results for large macrocystic head and neck lymphatic malformations. Microcystic and mixed lesions continue to provide a therapeutic challenge.

Angioplasty for Renal Artery Stenosis in Pediatric Patients: An 11-year Retrospective Experience

PURPOSE Studies of long-term percutaneous transluminal angioplasty (PTA) results have been less extensive in children than in adults. The authors sought to evaluate the outcomes of PTA for pediatric renovascular hypertension. MATERIALS AND METHODS The authors retrospectively evaluated 19 hypertensive children (ages 2-18 years) who underwent renal PTA from 1997-2009. Angiograms were reviewed in consensus to characterize lesions. This information was correlated with data from chart review to determine clinical outcomes. RESULTS Seven patients had neurofibromatosis type 1 (NF1), and 12 had fibromuscular dysplasia (FMD); one was lost to follow-up. Technical success was achieved in 29 of 32 lesions (91%). Cure of hypertension was achieved in seven of 18 patients (39%) and improvement in three (17%). There was a failed hypertension response in eight (44%): two with refractory stenosis, four with recurrent stenosis, and two with no response despite technical success. PTA was repeated in five children, all with failed response. Cure or improvement was seen in five of seven patients with NF1 and five of 11 with FMD. Most (nine of ten) patients with cure/improvement had single lesions or discrete lesions ≤ 10 mm. Residual stenosis < 10% was associated with cure/improvement (P = .0395). Three of five with bilateral and two of two with intraparenchymal disease demonstrated failure. The percentage of initial stenosis and presence of ostial lesions, aneurysms, or collaterals were not predictive of clinical response to PTA (P > .05). Cutting balloons were used after failure to efface with conventional balloons in seven patients and was successful in five of seven. CONCLUSIONS Despite a high rate of technical success, PTA provided a clinical benefit in a smaller majority of children. This study characterizes the utility of pediatric renal angioplasty and suggests criteria that may be prognostic of patient response.

The role of CT angiography in the evaluation of pediatric renovascular hypertension

Historically, the evaluation of renovascular hypertension has been accomplished by US, renal scintigraphy and digital subtraction angiography. Based on its high accuracy reported in adults renal CT angiography (CTA) with pediatric-appropriate low radiation dose techniques has become an important tool in the workup of renovascular hypertension in children. Renal CTA has several advantages over more conventional imaging modalities, including rapid and non-invasive acquisition, high resolution and easy reproducibility. Additionally, in our experience high-quality renal CTA can be performed using low-dose radiation exposures and can be acquired without sedation in most instances. This article illustrates by examples the usefulness of renal CTA for diagnosis of childhood renovascular hypertension and provides an overview of renal CTA findings in the most common childhood renovascular diseases.

The role of radiographs and US in developmental dysplasia of the hip: how good are they?

Developmental dysplasia of the hip (DDH) includes a variety of states in the developing fetal, neonatal and infant hip. Initial pathology is the abnormal laxity of the hip joint making it susceptible to displacement of the femoral head from the acetabulum. Sustained subluxation or dislocation of the femoral head over time prevents normal development of the acetabulum and results in a predictable pattern of acetabular growth disturbance that is termed hip dysplasia. DDH occurs six times more often in girls than in boys, occurring 60% of the time in the left hip, 20% in the right hip, and 20% bilaterally [1]. A number of accepted risk factors exist for DDH and include positive family history, breech position found just before birth, and the presence of an intrauterine postural deformity such as neonatal clubfoot or torticollis [2–6]. Some areas in the world have higher incidences of DDH than others, and both genetic and environmental effects appear to play roles. In parts of the world where infants are carried with their hips in abduction from early in life, lower rates of DDH are observed, while cultures that wrap infants in extended hip positions exhibit higher rates of DDH. On balance, the reported incidence of abnormal neonatal clinical examinations indicative of neonatal laxity ranges from 1% to 2%, of which approximately one tenth are truly DDH, creating a DDH incidence of 0.1–0.2% [2, 3, 7–9]. A variety of childhood conditions have DDH as a comorbidity, but not presenting in the typical neonatal and infant manner as noted above. Some like to segregate these separately under the heading of teratologic dislocations and dysplasia. For example, 35% of children with cerebral palsy will develop DDH [10]. Some other notable conditions with development of hip dysplasia would include myelodysplasia, arthrogryposis, caudal regression syndrome, Larsen syndrome, Stickler syndrome, multiple epiphyseal dysplasia, Trevor disease, spondyloepiphyseal dysplasias, metatropic dysplasia, and some of the mucopolysaccaridoses, notably Morquio disease [11].

Pediatric Enteric Feeding Techniques: Insertion, Maintenance, and Management of Problems

Enteral feeding is considered a widespread, well-accepted means of delivering nutrition to adults and children who are unable to consume food by mouth or who need support in maintaining adequate nutrition for a variety of reasons, including acute and chronic disease states. Delivery of enteral feeding to nutritionally deprived patients may be achieved by several means. In this article, the indications and insertion of enteral access in children will be reviewed. In addition, common complications and management of problems will be discussed.

Radiologically Placed Tunneled Hemodialysis Catheters: A Single Pediatric Institutional Experience of 120 Patients

PURPOSE To report the outcome of tunneled dialysis catheter insertion in 120 patients. MATERIALS AND METHODS A retrospective review of the interventional radiology database and electronic medical records of 120 patients who had tunneled dialysis catheters inserted from April 1997 to July 2010 was performed with institutional review board approval. There were 61 female patients and 59 male patients, with a mean age of 13.3 years (range, 0.2-28.5 y). A total of 193 primary insertions and 330 salvage procedures were performed. RESULTS The technical success rate for primary catheter insertions was 100%. Immediate complications included self-limiting tract bleeding and air embolism in two of 193 insertions each (1.03%). Mean indwell duration for primary insertions was 66 catheter-days (range, 1-765 d), compared with a total mean of 159.4 catheter-days (range, 1-1,034 d). Rates of infection and mechanical complications were 0.21 and 0.9 per 100 total catheter-days, respectively. Mechanical and infections complications were increased in children younger than 9 years of age and weighing less than 20 kg. The catheter removal rates for infection and mechanical complications were 0.084 and 0.081 per 100 catheter-days, respectively. Medical salvage procedures, ie, intracatheter thrombolytic agent use or antibiotic therapy (52.1%) and interventional radiologic catheter salvage procedures (47.1%), increased catheter survival by an average of 54.8 days (range, 0-959 d). CONCLUSIONS Radiologic placement of tunneled hemodialysis catheters is a safe and technically successful procedure in pediatric patients. However, there is a high rate of infectious and mechanical complications, particularly in younger and smaller patients.

The role of comparative panoramic visualization of radiographs in the diagnosis of developmental dysplasia of the hip: reply to Daza and Osorio

Sir, We read with interest the recent letter of Drs. Daza and Osorio [1] concerning radiography in developmental dysplasia of the hip (DDH) and are pleased to note their comments and respond to them. We are in full agreement about their depiction of findings in DDH and their explanation of the correlation with normal and abnormal stresses upon the developing neonatal and infant acetabulum. When one examines the literature and history of medical care of DDH, one finds many methods over the years that have been developed radiographically to examine qualitatively and quantitatively the hip joints of infants and children. All are helpful, with some more than others. Our recent article was published in a supplement of Pediatric Radiology that summarized our contribution to the postgraduate course at the 2008 annual meeting of the Society for Pediatric Radiology where the theme was “Evidence-Based Imaging in Pediatrics.” Our task was to examine the last decade of literature on imaging in DDH and report upon the latest available information of whether outcomes in babies with DDH are improved by imaging. In doing so, we reviewed all modalities and comparisons with clinical examination that we could find. Admittedly, we searched only in English. The development and evolution of hip sonography in the last 20 years has been in response to the late emergence of DDH that previously had not been prevented by clinical examination alone or the accompanying use of radiography. In our opinion, the best evidence, as reported in our article, has come out of two Norwegian randomized controlled trials [2, 3]. In babies without risk factors, no statistical difference has been found between expert clinical hip examiners and expert hip sonologists in preventing the rare emergence of cases of late DDH. In babies with DDH risk factors, there has been a trend, not statistically significant, of hip sonography being slightly better diagnostically than clinical examination alone. Some evidence and opinion suggest that when clinical examiners are inexperienced or are unsure of their findings, the use of imaging is likely to be more sensitive in detecting DDH or confirming normal. We are not aware of any large-scale recent trials of infant AP pelvic radiography being compared to clinical hip examination and then checking long-term outcome and the late discovery of DDH. In our opinion, selective use of hip radiography remains a useful adjunct in the care of children beyond early infancy in the follow-up of DDH but has not been shown to improve outcomes when used in routine neonatal and early infant screening.

Developmental Dysplasia of the Hip

■ Skilled clinical examiners are capable of detecting the vast majority of developmental dysplasia of the hip (DDH) in neonates, and this remains the primary screening method in the United States. Ultrasound (US) is no better than these examiners but may improve DDH diagnosis or exclusion for less-experienced clinical examiners (strong evidence).