14. Holzer R, Qureshi S, Ghasemi A, Vincent J, Sievert H, Gruenstein D, et al. Stenting of aortic coarctation: acute, intermediate, and long-term results of a prospective multi-institutional registry–Congenital Cardiovascular Interventional Study Consortium (CCISC). Catheter Cardiovasc Interv. 2010;76(4):553-63.

INTRODUCTION: Since the 1980s, stent implantation has evolved as an important therapeutic strategy for coarctation of the aorta. However, available data is frequently flawed by short follow-up, lack of adequate follow-up imaging, and retrospective nature of data collection.

METHODS: Data was prospectively collected using a multicenter registry congenital cardiovascular interventional study consortium (CCISC). Between 2000 and 2009, 302 patients from 34 centers with a median weight of 58 kg underwent stent implantation for coarctation. Eligible patients (44%) completed intermediate follow-up (3-18 months) with integrated imaging (cath, CT, MRI), whereas 21% completed long-term follow-up (>18-60 months). Procedural success was defined as UL/LL systolic gradient of less than 20 mm Hg, lack of significant recurrent obstruction, and freedom from unplanned repeat intervention.

RESULTS: Acute procedural success was 96%. Cumulative intermediate success was 86%, and cumulative long-term success was 77%. Unplanned repeat interventions were required in 4%, and aortic wall complications were seen in 1% of patients (dissection n = 1 and aneurysm n = 3). Other adverse events (n = 15) occurred mainly acutely and included technical complications such as stent malposition (n = 9). At long-term follow-up, 23% of patients continued to have systolic blood pressure above the 95th centile, 9% had an upper-to-lower limb blood pressure gradient in excess of 20 mm Hg, and 32% were taking antihypertensive medication.

CONCLUSIONS: This study documented acute, intermediate, and long-term outcome data comparable or superior with other surgical or interventional series. However, even with successful initial stent therapy, patients continue to require long-term follow-up and have associated long-term morbidity, relating to aortic wall complications, systemic hypertension, recurrent obstruction as well as need for repeat intervention.

18. Ibrahimi DM, Tamargo RJ, Ahn ES. Moyamoya disease in children. Childs Nerv Syst. 2010;26(10):1297-308.

PURPOSE: Moyamoya disease, a rare cause of pediatric stroke, is a cerebrovascular occlusive disorder resulting from progressive stenosis of the distal intracranial carotid arteries and their proximal branches. In response to brain ischemia, there is the development of basal collateral vessels, which give rise to the characteristic angiographic appearance of moyamoya. If left untreated, the disease can result in overwhelming permanent neurological and cognitive deficits.

METHODS: Whereas moyamoya disease refers to the idiopathic form, moyamoya syndrome refers to the condition in which children with moyamoya also have a recognized clinical disorder. As opposed to adults who typically present in the setting of intracranial hemorrhage, the classic pediatric presentation is recurrent transient ischemic attacks and/or completed ischemic strokes.

RESULTS: Surgical revascularization, including direct and indirect techniques, remains the mainstay of treatment, and has been shown to improve long-term outcome in children with moyamoya.

CONCLUSION: The authors discuss the diagnosis and treatment of moyamoya disease in the pediatric population.

19. Jallo GI, Gailloud P. Pediatric vascular disorders. Editorial. Childs Nerv Syst. 2010;26(10):1261.

20. Kondziolka D, Kano H, Yang HC, Flickinger JC, Lunsford L. Radiosurgical management of pediatric arteriovenous malformations. Childs Nerv Syst. 2010;26(10):1359-66.

PURPOSE: Hemorrhage from an arteriovenous malformation (AVM) is the commonest cause of childhood stroke. Management options for children include observation and medical management, surgical resection, endovascular embolization, or stereotactic radiosurgery, alone or in combination.

METHODS: Radiosurgery is used for high-risk malformations in critical brain locations. While this goal is being achieved, there should be limited morbidity and hopefully no mortality from hemorrhage or radiation-induced brain injury.

RESULTS: Physicians who consider AVM radiosurgery cite one or more of the following: (1) that radiosurgery is an effective therapy required for the management of deep-brain AVMs; (2) that radiosurgery is an effective therapy for residual AVMs after subtotal resection; (3) that radiosurgery is worthwhile in an attempt to lower management risks for AVMs in functional brain locations; (4) since embolization does not cure most AVMs, additional therapy such as radiosurgery may be required; and (5) microsurgical resection may not be the best choice for some children.

CONCLUSION: Radiosurgery is the first and only biologic AVM therapy; it represents the beginnings of future cellular approaches to vascular malformation diseases. For this reason, the future of radiosurgery may be impacted positively by the development of other biologic strategies such as brain protection or endothelial sensitization.

21. Pearl M, Gomez J, Gregg L, Gailloud P. Endovascular management of vein of Galen aneurysmal malformations. Influence of the normal venous drainage on the choice of a treatment strategy. Childs Nerv Syst. 2010;26(10):1367-79.

INTRODUCTION: Vein of Galen arteriovenous malformations (VGAM) are rare intracranial vascular lesions mostly involving young children. Endovascular therapy is the current standard of care. Albeit interventional techniques have greatly reduced the once dismal vital and functional prognoses previously associated with these lesions, the treatment of VGAMs remains a complex therapeutic challenge.

DISCUSSIONS: This article reviews the available endovascular options for VGAM therapy, emphasizing three points that we have identified as critical in our practice for the establishment of a treatment strategy: (1) the importance of the deep cerebral venous anatomy, in particular the existence of normal drainage through the Galenic system in spite of the VGAM; (2) the concept of treatment staging, for arterial as well as for venous interventions; and (3) the definition of a therapeutic goal that can be attained at a reasonable cost in terms of complication risks and functional outcome.

22. Puttgen KB, Pearl M, Tekes A, Mitchell SE. Update on pediatric extracranial vascular anomalies of the head and neck. Childs Nerv Syst. 2010;26(10):1417-33.

PURPOSE: Vascular anomalies most frequently present at birth or in early childhood, and the craniofacial region is the most common site of involvement. A long history of misleading nomenclature born of confusion about the presentation and natural history of various vascular anomalies has made appropriate diagnosis difficult. The present article emphasizes the importance of clarity of nomenclature for proper diagnosis, both clinically and radiographically, to guide appropriate therapy. In addition, updates on clinical concepts, imaging, and treatment strategies will be discussed. Pediatric vascular anomalies can be divided into two broad categories: vascular tumors and vascular malformations. This biologic classification is based on differences in natural history, cellular turnover, and histology. An updated classification was introduced in 1996 by the International Society for the Study of Vascular Anomalies (ISSVA) to include infantile hemangioma variants, other benign vascular tumors, and combined lesions. Widespread confusion propagated throughout the literature and in clinical practice stems from the continued improper use of many of the terms used to describe vascular tumors and malformations ignoring their pathophysiology. This leads to errors in diagnosis and the dissemination of misinformation to patients and clinicians. Certain terms should be abandoned for more appropriate terms. The clinical presentation usually identifies what general type of vascular anomaly is present, either vascular tumor or vascular malformation. Imaging provides crucial information about the initial diagnosis and aids in follow-up. CONCLUSIONS: Adoption and use of uniform nomenclature in the ISSVA classification system is the first vital step in correct diagnosis and treatment of often complicated vascular tumors and vascular malformations. A multidisciplinary team approach is necessary to provide optimal care for patients, and the necessity for specialists in all areas to communicate using standardized terminology cannot be overemphasized.

23. Zuccaro G, Arganaraz R, Villasante F, Ceciliano A. Neurosurgical vascular malformations in children under 1 year of age. Childs Nerv Syst. 2010;26(10):1381-94.

PURPOSE: This study aims to analyze the clinical and radiological findings, timing and type of treatment, and outcome in children under 1 year of age that presented with neurosurgical vascular malformations.

METHODS: A retrospective review of 23 children under 1 year of age with neurosurgical vascular malformations was performed at a single institution between 1999 and 2009.

RESULTS: The lesions found in this age group were: 10 vein of Galen aneurysmal malformations (VGAMs), 5 arteriovenous malformations (AVM), 2 pial arteriovenous fistulas (AVF; 1 in the brain and 1 in the spinal cord), 2 cavernous malformations, 2 dural sinus malformations (DSMs) in the posterior fossa with negative angiography which after surgery turned out to be embryonal malformations of dural sinuses, 1 sacular aneurysm, and 1 dural arteriovenous fistula (DAVF) that drained toward the vein of Galen. Of the 10 patients with VGAM, 8 presented choroidal type and 2 mural type. Two patients with choroidal VGAM were born in dramatically severe clinical condition; therefore, we decided to withhold aggressive treatment, and they died within 48h after birth. The other eight patients with choroidal VGAM received endovascular treatment between 1 and 3 staged embolizations. In four of them, total occlusion was achieved and subtotal and partial in the others. One patient had complications and evolved with severe developmental delay. Another patient with partial occlusion died, and another patient with previous developmental delay stopped treatment because of parental decision making. Five patients evolved with normal development and one with mild delay. Only one patient required shunt. Hydrocephalus was solved after endovascular treatment in the rest of the patients. Regarding the five AVMs, four were treated with microsurgical approach achieving total resection of the lesion and normal developmental milestones except for one patient with brainstem AVM that was admitted with quadriparesis and coma. In the patient with basal ganglia AVM, the lesion spontaneously disappeared. From the two pial AVFs, the frontal one was microsurgically treated and the spinal one received endovascular session achieving 50% of lesion occlusion for which further treatment is needed. The two cavernous malformations were operated achieving total resection with normal development. The two children with DSM received surgical resection without complications and normal development. The rare case of sacular aneurysm at this age was occluded at the time of diagnostic procedure due to the bad clinical condition of the patient and the hematoma was removed immediately in the operating room. The only case of DAVF died of respiratory intercurrence after three sessions of endovascular treatment.

CONCLUSIONS: In this neonatal age group (first year of life), we can find the whole range of neurosurgical vascular pathology: VGAM, AVM, cavernous malformation, DSM, pial AVF, DAVF, and sacular aneurysm. VGAM is the most frequent vascular malformation during the first year of age. The early treatment of vascular malformations prevents its adverse effects on a developing brain. A multidisciplinary team composed by endovascular and surgical specialists is necessary to discuss and treat each case.

30. Abraham RF, Shapshay S, Galati L. Botulinum toxin-assisted endoscopic repair of traumatic vocal fold avulsion. Ear Nose Throat J. 2010;89(9):452-8.

Blunt traumatic laryngeal injury in children often leads to intralaryngeal soft-tissue damage, which can quickly compromise an already small airway. Injuries requiring operative intervention have historically been repaired via open approaches such as thyrotomy and laryngofissure. These approaches carry significant long-term sequelae that can compromise the airway, deglutition, and voice. We describe a safe and effective alternative to open repair that includes the use of a botulinum toxin chemical myotomy to ensure optimal healing. We used this procedure to treat a 13-year-old boy who had experienced a traumatic avulsion of the true vocal folds. Postoperatively, his voice outcome was satisfactory, as evidenced by a marked improvement in his pediatric Voice Handicap Index score. No complication or compromise of the airway or swallowing occurred, and resolution of the botulinum effect was observed by 6 months postoperatively. The endoscopic approach supplemented by botulinum toxin injection avoids scarring and allows for safe postoperative extubation. Compared with open repair, it is associated with a shorter hospital stay and a lower risk of stenosis and fibrosis.

31. Brown S, Boshoff D, Rega F, Eyskens B, Meyns B, Gewillig M. Dilatable pulmonary artery banding in infants with low birth weight or complex congenital heart disease allows avoidance or postponement of subsequent surgery. Eur J Cardiothorac Surg. 2010;37(2):296-301.

OBJECTIVE: This study evaluated the efficiency and feasibility of dilatable bands in selected patients.

METHODS: Two types of dilatable handmade bands were retrospectively evaluated and divided into two groups: main pulmonary artery bands and bilateral branch pulmonary artery bands (hybrid stage I palliation). Stepwise balloon angioplasty (BA) was performed, increasing the diameter either to completely dilate with total release of the band, or in others, to partially dilate the bands in order to improve flow and/or saturation.

PATIENTS AND RESULTS: Balloon angioplasty was performed in 20 patients (median birth weight 2.9 kg, range: 1.3-4.5 kg). Main pulmonary artery: Partial dilation: Six patients: Large ventricular septal defects (VSDs) and complex lesions requiring additional surgery. Progressive dilation allowed postponement of surgery in four children and allowed percutaneous VSD closure in one. Complete dilation: Eight patients: Spontaneous restriction of VSDs occurred in six patients; the bands were subsequently percutaneously completely released after a median of 39 weeks (7-91 weeks). The median gradient decreased from 90 to 38 mmHg (p<0.0001). Bilateral branch pulmonary artery: An average 8.5% increase in saturations was achieved in five patients, and in one patient, a hybrid procedure with borderline left ventricle, complete dilation allowed successful percutaneous biventricular repair.

CONCLUSIONS: Dilation of both main and bilateral branch pulmonary artery bands is possible, effective and safe. Dilatable main pulmonary artery bands allow for progressive dilation with postponement of surgery or complete release of the bands. Bilateral dilatable branch pulmonary bands offer palliative benefit, especially in hybrid cases where pulmonary blood flow may be limited by the bands before the ideal conditions for a stage II procedure exist.

32. Shennib H, Rodriguez-Lopez J, Ramaiah V, Wheatley G, Kpodonu J, Williams J, et al. Endovascular management of adult coarctation and its complications: intermediate results in a cohort of 22 patients. Eur J Cardiothorac Surg. 2010;37(2):322-7.

OBJECTIVE: To determine the safety and effectiveness of current endovascular treatment in adult patients with thoracic aortic coarctation and its complications.

METHODS: A cohort of 22 patients was treated for late presenting primary or recurrent coarctation or aneurysmal formation at varying intervals following childhood intervention.

RESULTS: Ten patients with recently discovered de novo coarctations were treated with balloon-expandable stents, and an endoluminal graft (ELG) was used in one additional patient. In the other 11 patients with recurrent lesions, three underwent repeat balloon dilation and stenting; eight patients with recurrence with aneurysms received ELGs. The gradients across the coarctation decreased from 49 + 16 to 4 + 7 mmHg (p = 0.001), and the diameters increased from 10 + 4 to 19 + 4mm (p = 0.001). In five of the eight patients (63%) with aneurysms, the ELG covered the subclavian artery, and a carotid subclavian bypass was necessary. Two patients required iliac artery access. No early major complications occurred. At mean follow-up of 31 + 15.6 months, one patient with type II leak resolved spontaneously and another developed neck dilation and type I leak, requiring a second ELG placement. All patients except one had improvements in symptoms and better hypertension control.

CONCLUSIONS: We conclude that primary or secondary endovascular intervention in adults with de novo or recurrent coarctation and aneurysms is feasible with good intermediate results.

35. Becce F, Theumann N, Rochette A, Larousserie F, Campagna R, Cherix S, et al. Osteoid osteoma and osteoid osteoma-mimicking lesions: biopsy findings, distinctive MDCT features and treatment by radiofrequency ablation. Eur Radiol. 2010;20(10):2439-46.

OBJECTIVE: To report the biopsy findings of osteoid osteoma (OO) and OO-mimicking lesions, assess their distinctive multidetector computed tomography (MDCT) features and evaluate treatment by radiofrequency ablation (RFA).

METHODS: In this multicentric retrospective study, 80 patients (54 male, 26 female, mean age 24.1 years, range 5-48) with presumed (clinical and MDCT features) OO were treated by percutaneous RFA between May 2002 and June 2009. Per-procedural biopsies were always performed. The following MDCT features were assessed: skeletal distribution and location within the bone, size, central calcification, surrounding osteosclerosis and periosteal reaction. Clinical success of RFA was evaluated.

RESULTS: Histopathological diagnoses were: 54 inconclusive biopsies, 16 OO, 10 OO-mimicking lesions (5 chronic osteomyelitis, 3 chondroblastoma, 1 eosinophilic granuloma, 1 fibrous dysplasia). OO-mimicking lesions were significantly greater in size (p = 0.001) and presented non-significant trends towards medullary location (p = 0.246), moderate surrounding osteosclerosis (p = 0.189) and less periosteal reaction (p = 0.197), compared with OO. Primary success for ablation of OO-mimicking lesions was 100% at 1 month, 85.7% at 6 and 12 months, and 66.7% at 24 months. Secondary success was 100%.

CONCLUSION: Larger size, medullary location, less surrounding osteosclerosis and periosteal reaction on MDCT may help differentiate OO-mimicking lesions from OO. OO-mimicking lesions are safely and successfully treated by RFA.

39. Greenberg SB, Bhutta S, Braswell L, Chan F. Computed tomography angiography in children with cardiovascular disease: low dose techniques and image quality. Int J Cardiovasc Imaging. 2011.

Dose reduction techniques for computed tomography angiography (CTA) in children with cardiovascular diseases have the potential of reducing risks of radiation-induced cancer. To evaluate effectiveness of these techniques, both radiation dose and image quality must be compared. While clinically practical methods of estimating effective dose are available, there are no generally accepted metrics for the assessment of image quality in CTA. We introduce a measurable and reproducible image quality index, CTA QI. Using this index, along with calculated effective dose, we test the hypothesis that volume scan CTA delivers comparable image quality at substantially reduced radiation dose when compared to helical CTA. CTA QI is a measure of intraluminal contrast variation in three-dimensions, and it is calculated from standardized measurements of means and standard deviations of Hounsfield units in the thoracic descending aorta. From institutional database, 83 studies of CTA for thoracic cardiovascular diseases were retrospectively identified. CTA QI values were independently measured by two radiologists and compared using correlation. CTA QI and DLP-derived effective dose were compared for the following groups: non-cardiac gated wide-detector and helical CTA, ECG-synchronized retrospective wide-detector and helical CTA, ECG-synchronized wide detector retrospective and target technique CTA. Statistical significance was evaluated with the Student-t test. The correlations of CTA QI values between the radiologists were 0.83 and 0.92 for non-gated studies and ECG-synchronized studies respectively. Comparing non-gated volume scan CTA to helical CTA, there was a radiation dose reduction of 69% (P < 0.0001) without a significant change in CTA QI (1.4 +/- 1.0 vs. 1.9 +/- 1.4, P = 0.13). Comparing retrospective ECG-synchronized wide-detector CTA to helical CTA, there was a radiation dose reduction of 46% (P < 0.0001) with and improvement in CTA QI (1.0 +/- 0.8 vs. 3.7 +/- 3.4, P < 0.01). Comparing ECG-synchronized wide-detector target CTA to retrospective CTA, there was a radiation dose reduction of 68% (P < 0.0001, but at the cost of a significant reduction in CTA QI (2.0 +/- 1.0 vs. 0.8 +/- 0.4, P < 0.0044). CTA QI is a simple, reproducible metric of image quality suited for comparing CTA studies. Using this quality index, we establish that CTA performed with wide-detector scan techniques can yield substantially lower radiation dose without compromising diagnostic imaging quality. A wide-detector target technique can further reduce effective dose compared to wide-detector retrospective ECG-synchronization, but with a reduction in image quality.

47. Ellis MJ, Armstrong D, Dirks PB. Large vascular malformation in a child presenting with vascular steal phenomenon managed with pial synangiosis. J Neurosurg Pediatr. 2011;7(1):15-21. The management of large and giant arteriovenous malformations (AVMs) in patients presenting with nonhemorrhagic neurological deficits secondary to vascular steal phenomenon is challenging and controversial. In many cases, large AVMs cannot be completely excised or cured, leaving patients with residual or partially treated AVMs, the natural history of which is unknown. Additionally, large, diffuse vascular malformations with multiple, small feeders, slow flow, or so-called cerebral proliferative angiopathy represent a related but distinct clinical and angiographic entity that may require a different therapeutic approach than traditional brain AVMs. The current management of children with other conditions of chronic cerebral hypoperfusion, such as moyamoya disease, involves consideration of surgical revascularization to enhance blood flow to the compromised hemisphere. Here, the authors present the case of a young child with a large thalamic vascular malformation who presented with clinical and radiological features of vascular steal and ischemia. In an effort to augment flow to the hypoperfused brain and protect against future ischemia, the authors treated the child with unilateral pial synangiosis. At 12 months, postoperative angiography demonstrated robust neovascularization, and the child has not sustained any further ischemic events. The authors discuss concept of vascular malformation-related hypoperfusion and the utility of indirect revascularization for inoperable vascular malformations presenting with ischemic symptoms.

48. Li AH, Armstrong D, terBrugge KG. Endovascular treatment of vein of Galen aneurysmal malformation: management strategy and 21-year experience in Toronto. J Neurosurg Pediatr. 2011;7(1):3-10.

OBJECT: The treatment of vein of Galen aneurysmal malformation (VGAM) is among the most challenging of all the neurovascular disorders. METHODS: Between 1984 and 2005, 26 consecutive patients with VGAMs were treated by the authors’ group, and their data were prospectively collected; 12 patients presented with congestive heart failure (CHF) and 10 had hydrocephalus. Five patients did not undergo endovascular treatment because of minimal symptoms or severe comorbidities. Twelve patients underwent embolization for refractory CHF requiring ventilation: 7 of these 12 patients had the procedure in the neonatal stage (5 survived), and 5 were treated in infancy or childhood following successful aggressive medical treatment (4 survived). The other 9 patients underwent endovascular surgery to treat a progressively enlarging head circumference; there was imaging evidence of ventricular enlargement and/or signs of developmental delay (6 underwent surgery in infancy and 3 in childhood; 1 patient died).

RESULTS: The survival rate in this series was 76.9% (20 of 26). Fourteen (66.7%) of 21 patients who underwent endovascular treatment had no developmental delay. An analysis of various factors demonstrated that comorbidities and embolization effect (procedure success and long-term effect) were prognostic factors of survival. In addition, the patient’s age at embolization was significantly higher in those with developmental delay than in those without (559.86 +/- 535.43 days vs 94.83 +/- 95.77 days, respectively; p = 0.028).

CONCLUSIONS: The authors conclude that neonatal VGAMs can be treated successfully with a strategic approach integrating antenatal diagnosis, endovascular surgery, treatment at intensive care facilities, and the cooperative efforts of different specialties. In the authors’ experience, patients in whom VGAM was diagnosed and managed in infancy or childhood had more than 90% long-term survival.

49. Rao AP, Bojahr H, Beski S, MacCallum PK, Renfrew I. Role of interventional radiology in the management of morbidly adherent placenta. J Obstet Gynaecol. 2010;30(7):687-9.

The incidence of morbidly adherent placenta is rising and is directly proportional to the rate of rise of caesarean deliveries. Despite improvement in antenatal diagnosis, by accuracy of ultrasound and MRI techniques, placenta accreta is still associated with a high maternal morbidity rate. Management of pregnancies with a morbidly adherent placenta is extremely challenging and is becoming an increasingly common problem for maternity units globally. The main challenges include controlling the haemorrhage and dissection of the invaded tissues. Traditionally, these cases were managed by caesarean hysterectomy. There has now been a shift towards conservative management of placenta accreta, involving uterine and placental conservation, with the aid of interventional radiology by means of insertion of occluding balloons into appropriate vessels. We describe three cases of morbidly adherent placentas, managed at our unit where meticulous preoperative planning, multidisciplinary approach and the key role of interventional radiology led to a safe outcome for both the mother and the baby.

51. Hlavacek AM. Imaging of congenital cardiovascular disease: the case for computed tomography. J Thorac Imaging. 2010;25(3):247-55.
Computed tomographic angiography is a rapidly evolving modality that is well suited for congenital cardiac imaging. Although echocardiography and magnetic resonance imaging carry an established role for evaluating patients with congenital cardiovascular disease, computed tomographic angiography provides important advantages over each of these modalities in certain clinical scenarios. Its practicality, high spatial resolution, inherent 3-dimensional nature, and decreased need for sedation make it a very useful tool in this patient population. This study reviews the utility of computed tomographic angiography and addresses the risks and benefits of this modality in comparison with other imaging modalities. Despite the exposure to ionizing radiation, newer technologies and techniques are being introduced that are decreasing the risks associated with computed tomographic imaging to exceedingly small levels. When viewed in the context of other risks these patients encounter, computed tomographic angiography is a useful adjunct to echocardiography in patients with congenital heart disease and is often preferable to magnetic resonance imaging in certain patients.

52. Ikeda O, Tamura Y, Nakasone Y, Yamashita Y, Okajima H, Asonuma K, et al. Percutaneous transluminal venoplasty after venous pressure measurement in patients with hepatic venous outflow obstruction after living donor liver transplantation. Jpn J Radiol. 2010;28(7):520-6.

PURPOSE: The aim of this study was to evaluate retrospectively the outcome of percutaneous transluminal venoplasty (PTV) after venous pressure measurement in patients with hepatic venous outflow obstruction following living donor liver transplantation (LDLT).

MATERIALS AND METHODS: We studied 24 consecutive patients suspected of having hepatic venous outflow obstruction after LDLT. Pressure gradients were measured proximal and distal to the lesion, and gradient values >3 mmHg were considered hemodynamically significant. We evaluated the technical success, complications, outcome of venoplasty and recurrence, and the patency rate.

RESULTS: In all, 11 female patients manifested a pressure gradient >3 mmHg across the anastomotic site; they underwent subsequent PVT. The initial balloon venoplasty procedure was technically successful in 10 of the 11 patients (91%), and the pressure gradient was reduced from 5.8 to 1.1 mmHg (P < 0.01). Clinical improvement was observed in 9 of these 10 patients; one patient failed to improve and underwent retransplantation. Recurrent obstruction occurred in four patients; they underwent PTV with (n = 2) or without (n = 2) stent placement. There were no major procedural complications.

CONCLUSION: PTV following venous pressure measurement is an effective and safe treatment for venous outflow obstruction in patients subjected to LDLT. In patients with recurrent obstruction, re-venoplasty is recommended.

55. Chamoun RB, Jea A. Traumatic intracranial and extracranial vascular injuries in children. Neurosurg Clin N Am. 2010;21(3):529-42. Trauma continues to be the leading cause of death in children older than 1 year of age. Although vascular injuries are uncommon, they contribute significantly to the mortality and morbidity related to traumatic injuries in the pediatric age group. In a recently reported large series of children, the head and neck location constituted 19.4% of all pediatric vascular injuries and accounted for most of the mortality observed. Catheter angiography is still considered as the gold standard diagnostic modality. However, because of its invasive nature, other techniques such as computed tomography angiography and magnetic resonance angiography are emerging as alternative diagnostic screening tools. Traumatic vascular injuries can involve the carotid as well as the vertebral arteries. They can be extracranial or intracranial. As a result, traumatic vascular injuries are a heterogeneous group of entities with potential significant implication on the natural history and prognosis. The optimal management of these injuries remains unclear and current practice is largely individualized. This report reviews the available literature regarding the current trends in diagnosis and management of pediatric traumatic vascular injuries.

56. Guzman R, Steinberg GK. Direct bypass techniques for the treatment of pediatric moyamoya disease. Neurosurg Clin N Am. 2010;21(3):565-73.

Moyamoya is an increasingly recognized cause of stroke in children and adults. Identification of the disease early in its course with prompt institution of therapy is critical to providing the best outcome for patients. Revascularization surgery seems to be effective in preventing stroke in moyamoya, with direct techniques providing durable protection when performed at experienced centers.

58. Krings T, Geibprasert S, Terbrugge K. Classification and endovascular management of pediatric cerebral vascular malformations. Neurosurg Clin N Am. 2010;21(3):463-82.

Pediatric vascular malformations of the central nervous system differ from those seen in adults. Their classification may be based on symptoms, pathomechanics, patient’s age, morphologic features, or presumed etiology. This review describes the different classification schemes and the endovascular management options of these rare and challenging diseases. The proposed etiologic classification of pediatric vascular malformations may add to our understanding of these diseases in general because the phenotypic expression of a given vascular malformation can shed light on the nature and timing of the causative agent, thereby potentially opening up treatment modalities in the future that are directed against the triggering event rather than against the clinical manifestations or the morphologic appearance. With current endovascular methods, most vascular diseases can be approached safely and with good clinical results.

59. Patel NN, Mangano FT, Klimo P, Jr. Indirect revascularization techniques for treating moyamoya disease. Neurosurg Clin N Am. 2010;21(3):553-63.

There have been many indirect revascularization techniques described by surgeons for the treatment of moyamoya disease. These surgical procedures are typically used more commonly in pediatric, than in adults’, cases. Some of the techniques include: cervical sympathectomy, omental transplantation, multiple burr holes, encephalo-myo-synangiosis (EMS), encephalo-arterio-synangiosis (EAS), encephalo-duro-synangiosis (EDS), encephalo-myo-arterio-synangiosis (EMAS), encephalo-duro-arterio-synangiosis (EDAS), encephalo-duro-arterio-myo-synangiosis (EDAMS), encephalo-duro-galeo (periosteal)-synangiosis (EDGS), and combinations of all the above. This chapter will detail the technical aspects of many of these procedures and some of the reported clinical outcomes.

61. Suga K, Iwanaga H, Tokuda O, Okada M, Tanaka N, Matsunaga N. Steal phenomenon-induced lung perfusion defects in pulmonary arteriovenous fistulas: assessment with automated perfusion SPECT-CT fusion images. Nucl Med Commun. 2010;31(9):821-9.

PURPOSE: Lung perfusion impairment in patients with pulmonary arteriovenous fistula (AVF) was evaluated by automated deep inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images.

METHODS: Participants were 14 patients with a single (N=6) or multiple nodular AVFs (N=8) diagnosed by contrast-enhanced CT scan and/or pulmonary angiography. After the injection of 185MBq Tc-99m-macroaggregated albumin, a whole-body scan was obtained to quantify an intrapulmonary right-to-left shunt. Subsequently, DIBrH SPECT was obtained using the continuous rotating acquisition mode of a dual-headed SPECT system, which was automatically coregistered with DIBrH CT. The anatomic relationship between AVF and perfusion defects was assessed on the fusion images.

RESULTS: The whole-body scan depicted systemic organs indicating the presence of an intrapulmonary right-to-left shunt in all the patients. DIBrH SPECT showed 34 perfusion defects in these patients, which were located at the AVF and in the surrounding lungs of the AVF on the fusion images, regardless of the absence of morphologic abnormality on CT in all the patients. These defects were considered to be caused by the ‘steal phenomenon’ associated with the high and fast pulmonary arterial flow to each AVF, which were more extensive and severe in the multiple AVFs compared with a single AVF (P=0.0012), occasionally extending to the entire lobe with AVF or even to the adjacent lobe. In five patients, the fusion images detected a total of six tiny AVFs with unexpectedly extensive ‘steal phenomenon’-induced defects, which had been missed by other radiological imaging techniques. The summed value of the shunt index estimated by the whole-body scan and the lung perfusion defect extent estimated by DIBrH SPECT was significantly correlated with PaO2 in all the patients (P < 0.0001), with a better correlation compared with the shunt index alone.

CONCLUSION: In addition to the right-to-left shunt, ‘steal phenomenon’-induced perfusion defects are common in the surrounding lung of pulmonary nodular AVF and cause hypoxemia. DIBrH SPECT-CT fusion images contribute to the objective evaluation of ‘steal phenomenon’-induced lung perfusion impairment in AVF and the detection of tiny, subtle AVFs that may be missed by other radiological imaging techniques.

63. Tullus K. Renal artery stenosis: is angiography still the gold standard in 2011? Pediatr Nephrol. 2011.

Renovascular hypertension (RVH) is an unusual cause of hypertension in children that is important to diagnose as it is potentially curable with angioplasty or surgery. Digital subtraction angiography is the gold standard for diagnosing RVH; for other methods like ultrasound, isotope studies, magnetic resonance angiography and computed tomography angiography sensitivity is still too low to reliably exclude RVH. Clinical and laboratory criteria that suggest RVH will be proposed and recommendations when digital subtraction angiography should be performed will be made. A treatment algorithm that suggests when to use medical treatment, interventional radiology and surgery in children with RVH will be given.

64. Bevernage C, Maleux G, De Hertogh G, Miserez M. Life-threatening lower gastrointestinal bleeding in a 2-year-old boy treated by transcatheter embolization: uncommon features of a complicated Meckel diverticulum. Pediatr Radiol. 2010;40(10):1702-5.

A 2.5-year-old boy presented with life-threatening lower gastrointestinal (GI) bleeding. Radiological investigation, including US, CT and 99 m-Technetium (Tc) pertechnate scintigraphy, was negative. Emergency visceral angiography was performed, showing a left-side, non-branching artery, originating from a side branch of the superior mesenteric artery (SMA) with extravasation of contrast material. At the same time, embolization of the bleeding point was performed, resulting in haemostasis. In the days following the procedure the boy developed an intestinal obstruction. At laparoscopy, a complicated Meckel diverticulum was resected.

66. Schook CC, Mulliken JB, Fishman SJ, Alomari AI, Grant FD, Greene AK. Differential Diagnosis of Lower Extremity Enlargement in Pediatric Patients Referred with a Diagnosis of “Lymphedema”. Plast Reconstr Surg. 2010.

BACKGROUND: There are many causes for a large lower limb in the pediatric age group. These children are often mislabeled as having “lymphedema”, and incorrect diagnosis can lead to improper treatment. The purpose of this study was to determine the differential diagnosis in pediatric patients referred for lower extremity “lymphedema” and to clarify management.

METHODS: Our Vascular Anomalies Center database was reviewed between 1999 – 2010 for patients referred with a diagnosis of “lymphedema” of the lower extremity. Records were studied to determine the correct etiology for the enlarged extremity. Alternative diagnoses, gender, age-of-onset, and imaging studies also were analyzed.

RESULTS: A referral diagnosis of lower extremity “lymphedema” was given to 170 children; however, the condition was confirmed in only 72.9% of patients. Forty-six children (27.1%) had another disorder: micro/macrocystic lymphatic malformation (19.6%), non-eponymous combined vascular malformation (13.0%), capillary malformation (10.9%), Klippel-Trenaunay syndrome (10.9%), hemi-hypertrophy (8.7%), post-traumatic swelling (8.7%), Parkes Weber syndrome (6.5%), lipedema (6.5%), venous malformation (4.3%), rheumatologic disorder (4.3%), infantile hemangioma (2.2%), kaposiform hemangioendothelioma (2.2%), or lipofibromatosis (2.2%). Age-of-onset in children with lymphedema was older than patients with another diagnosis (p = 0.027).

CONCLUSION: “Lymphedema” is not a generic term. Approximately one-fourth of pediatric patients with a large lower extremity are misdiagnosed as having “lymphedema”; the most commonly confused etiologies are other types of vascular anomalies. History, physical examination, and often radiological studies are required to differentiate lymphedema from other conditions to ensure the child is managed appropriately.
68. Skalova S, Rejtar P. Safety profile of paediatric percutaneous ultrasonography-guided renal biopsies. Singapore Med J. 2010;51(6):481-3.

INTRODUCTION: Renal biopsy (RB) is a decisive diagnostic procedure for patients with renal disease. Our aim was to assess the safety of RB and the prevalence of associated clinical complications. METHODS: A total of 166 RBs were performed in 164 children (88 boys, 76 girls) in East Bohemia in 1997-2007. The mean age of the children was 12.9 +/- 4.1 years. All RBs were performed by a single consultant nephrologist. 27 biopsies were performed in 27 patients (16.3 percent) in 1997 under radiography control, while the remaining 139 biopsies (83.7 percent) were performed under ultrasonographic guidance. Renal ultrasonography (USG) following RB was not a general rule in patients who were biopsied under radiography control before 1998; therefore, only the USG results in patients after USG-guided RB (n = 139) were evaluated.

RESULTS: No major complications were encountered, and only minor complications occurred in 39 (23.5 percent) patients, which did not require medical intervention. The most common complication was asymptomatic perirenal haematoma, which was detected by USG one to three days after a USG-guided RB (30 out of 139 biopsies; 21.6 percent). Perirenal haematoma accompanied by abdominal pain occurred in two (1.4 percent) patients. Macroscopic haematuria was present in seven (4.2 percent) patients on Days 1-3 post biopsy. The complications were neither age-dependent nor were they related to the serum creatinine levels.

CONCLUSION: The results obtained are consistent with those in other reports of paediatric patients. The absence of major complications is a favourable outcome. Thus, the present practice of USG-guided percutaneous RB in children is safe and clinically beneficial.

69. Virayavanich W, Singh R, O’Donnell RJ, Horvai AE, Goldsby RE, Link TM. Osteoid osteoma of the femur in a 7-month-old infant treated with radiofrequency ablation. Skeletal Radiol. 2010;39(11):1145-9.

Osteoid osteoma occurs most commonly in children, adolescents, and young adults between the ages of 5 and 30 years. In the preschool age group, it is quite uncommon, accounting for only 3-8% of all osteoid osteoma cases. We report a case of osteoid osteoma in a 7-month-old infant, who presented with decreased use of the right lower extremity due to pain. Magnetic resonance imaging (MRI) showed an atypical appearance. A biopsy of the lesion, with histopathological examination, confirmed the diagnosis of osteoid osteoma. Radiofrequency ablation (RFA) of the nidus under computed tomography (CT) guidance was performed. The patient developed a recurrence after 3 months, which was treated with a second RFA. On subsequent follow-up, the infant did not show signs of pain after 1 month. In summary, this case report shows that osteoid osteoma can present in early infancy and can be successfully treated with RFA at this age, however, recurrence after the procedure can occur and close follow-up is recommended.