Josée Dubois

Imaging and therapeutic approach of hemangiomas and vascular malformations in the pediatric age group

Abstract Terminology regarding the vascular lesions of the soft tissues remains confusing. A single classification is necessary in order to decide on the proper investigation and the best treatment. At the Workshop on Vascular Anomalies in Rome in June 1996, the membership accepted the Mulliken and Glowacki classification, which differentiates vascular lesions into vascular tumors, including hemangiomas and vascular malformations. At Sainte-Justine, we have set up a multidisciplinary clinic for the discussion of problem patients with vascular anomalies, both in terms of diagnosis and treatment. In this review, we present our experience regarding the classification, the imaging modalities and the treatment of vascular anomalies. In our experience, Doppler ultrasound should be the initial imaging modality for recognizing vascular tumors from vascular malformations. CT scan or magnetic resonance imaging is best to evaluate the extent of the lesions prior to treatment. A multidisciplinary approach is essential to establish a correct diagnosis and define accordingly the appropriate treatment and follow-up.

Parkes Weber syndrome, vein of Galen aneurysmal malformation, and other fast‐flow vascular anomalies are caused by RASA1 mutations

Capillary malformation‐arteriovenous malformation (CM‐AVM) is a newly recognized autosomal dominant disorder, caused by mutations in the RASA1 gene in six families. Here we report 42 novel RASA1 mutations and the associated phenotype in 44 families. The penetrance and de novo occurrence were high. All affected individuals presented multifocal capillary malformations (CMs), which represent the hallmark of the disorder. Importantly, one‐third had fast‐flow vascular lesions. Among them, we observed severe intracranial AVMs, including vein of Galen aneurysmal malformation, which were symptomatic at birth or during infancy, extracranial AVM of the face and extremities, and Parkes Weber syndrome (PKWS), previously considered sporadic and nongenetic. These fast‐flow lesions can be differed from the other two genetic AVMs seen in hereditary hemorrhagic telangiectasia (HHT) and in phosphatase and tensin homolog (PTEN) hamartomatous tumor syndrome. Finally, some CM‐AVM patients had neural tumors reminiscent of neurofibromatosis type 1 or 2. This is the first extensive study on the phenotypes associated with RASA1 mutations, and unravels their wide heterogeneity. Hum Mutat 29(7), 959–965, 2008.

Diagnostic imaging of spinal deformities: reducing patients radiation dose with a new slot-scanning X-ray imager.

Study Design. Clinical trial comparing image quality and entrance dose between Biospace EOS system, a new slot-scanning radiographic device, and a Fuji FCR 7501S computed radiography (CR) system for 50 patients followed for spinal deformities. Objective. Based on their physical properties, slot-scanners show the potential to produce image quality comparable to CR systems using less radiation. This article validates this assertion by comparing a new slot-scanner to a CR system through a wide-ranging evaluation of dose and image quality for scoliosis examinations. Summary of Background Data. For each patient included in this study, lateral and posteroanterior images were acquired with both systems. For each system, entrance dose was measured for different anatomic locations. Methods. Dose and image quality being directly related, comparable images were obtained using the same radiograph tube voltage on both systems while tube currents were selected to match signal-to-noise ratios on a phantom. Different techniques were defined with respect to patients thickness about the iliac crests. Given dose amplitudes expected for scoliosis examinations, optically stimulated luminescence dosimeters were chosen as optimal sensors. Two radiologists and 2 orthopedists evaluated the images in a randomized order using a questionnaire targeting anatomic landmarks. Visibility of the structures was rated on a 4 level scale. Image quality assessment was analyzed using a Wilcoxon signed-rank tests. Results. Average skin dose was reduced from 6 to 9 times in the thoracoabdominal region when using the slot-scanner instead of CR. Moreover, image quality was significantly better with EOS for all structures in the frontal view (P < 0.006) and lateral view (P < 0.04), except for lumbar spinous processes, better seen on the CR (P < 0.003). Conclusion. We established that the EOS system offers overall enhanced image quality while reducing drastically the entrance dose for the patient.

Wireless capsule endoscopy for obscure small-bowel disorders: Final results of the first pediatric controlled trial

BACKGROUND AND AIMS Obscure small-bowel disorders are jejunal and ileal lesions undiagnosed by traditional imaging techniques (endoscopic, radiologic). We evaluated the diagnostic usefulness and safety of capsule endoscopy for obscure small-bowel disorders in children and adolescents. METHODS Comparative, prospective, self-controlled trials in patients (age, 10-18 y) suspected to have either small-bowel Crohns disease, polyps, or obscure gastrointestinal (GI) bleeding. Capsule results were compared with the diagnostic imaging studies normally used in this age group. RESULTS Among 20 patients suspected of Crohns disease, multiple lesions consistent with this diagnosis were observed by capsule endoscopy in 50%. Small-bowel Crohns disease was ruled out in 8 patients. Eosinophilic enteropathy was found in 2 others. For polyp detection (n = 6), capsule endoscopy yielded 100% concordance with the control studies when analyzed per patient. However, capsule endoscopy revealed a greater number (50%) of polyps. Among patients with obscure bleeding (n = 4), the capsule examination confirmed a diagnosis of vascular malformations in 3. Capsule endoscopy more accurately identified the precise source of bleeding compared with angiography. All 30 capsule studies were well tolerated, although 1 capsule was retained owing to an inflammatory stenosis. The capsule eventually was expelled after corticosteroid therapy. CONCLUSIONS Capsule endoscopy correctly diagnosed or excluded a bleeding source, small-bowel polyps, or Crohns disease of the small bowel in 29 of 30 patients. Capsule endoscopy permits an accurate, noninvasive approach for diagnosing obscure small bowel lesions in children over the age of 10.

Placenta percreta: Balloon occlusion and embolization of the internal iliac arteries to reduce intraoperative blood losses☆☆☆★

Obstetric hemorrhage is still a potential cause of maternal mortality and morbidity. Angiographic embolization techniques have been described in cases of postcesarean bleeding, vaginal wall hematomas, cervical ectopic pregnancies, and postpartum bleeding to control persistent bleeding from pelvic vessels. We describe two cases of pregnancy complicated with placenta percreta. Balloon occlusion and embolization of the hypogastric arteries were performed during the cesarean section and hysterectomy, resulting in a remarkable reduction in intraoperative blood loss. Balloon occlusion and embolization of the internal iliac arteries significantly reduce intraoperative blood losses.

Incidence and risk factors of catheter-related deep vein thrombosis in a pediatric intensive care unit: A prospective study

OBJECTIVE To estimate the incidence and to characterize risk factors for central venous catheter (CVC)-related deep vein thrombosis (DVT) in a pediatric intensive care unit. STUDY DESIGN Consecutive children admitted to a pediatric intensive care unit who required a CVC for more than 48 hours were examined by Doppler ultrasonography of the catheterized vein at days 2, 4, 6, or 7 after insertion and weekly thereafter until CVC removal. RESULTS The incidence of CVC-related DVT was 18.3% (17 of 93) (95% confidence interval = 10.2% to 25.8%). Thromboses were diagnosed within the first 4 days of catheter placement for 15 of 17 CVC-related thromboses. Multivariate analysis showed that risk factors most predictive of CVC-related DVT were presence of a cancer (odds ratio = 17.23, 95% confidence interval = 1.5 to 194) and young age (odds ratio for age = 0.72, 95% confidence interval = 0.54 to 0.96). CONCLUSION The frequency of CVC-related DVT is substantial in pediatric intensive care units. Risk is highest during the 4 days after insertion and decreases thereafter. The clinical impact, optimal prevention, and therapy of these thromboses remain to be determined.

Vascular anomalies: what a radiologist needs to know.

Most haemangiomas and vascular malformations are identified according to clinical criteria. A good knowledge of the classification and clinical characteristics of the vascular anomalies is necessary when managing these patients. However, some cases are challenging either because of an atypical presentation (e.g., soft-tissue mass with normal overlying skin) or because of classification difficulties. Doppler US and MRI are the two main imaging modalities that allow classification of the vascular anomalies and are useful in those clinically uncertain cases to establish the correct diagnosis. This aids the choice of the most appropriate treatment and to inform the parents of the prognosis. High-resolution grey-scale and Doppler US allow excellent visualization of most superficial masses. Doppler US is the easiest way to assess the haemodynamics of a vascular lesion and to clarify a doubtful diagnosis between a haemangioma and vascular malformation. MRI is the best technique for evaluating the extent of the lesions and their relationship to adjacent structures. While newly developed drugs from angiogenesis research labs are awaited, radiologists have an important role in the treatment of haemangiomas and vascular malformations. Intervention remains crucial in cases of alarming haemangiomas and venous malformations (VM), lymphatic malformations (LM) and arteriovenous malformations (AVM). A multidisciplinary team, including paediatricians, haematologists, surgeons and radiologists, must manage the problem cases both in terms of diagnostic work-up and therapeutic options. This paper will briefly discuss the imaging findings and treatment of vascular anomalies.

Toxicity profile of interferon alfa-2b in children: A prospective evaluation

The toxicity of interferon (IFN) alfa-2b therapy was prospectively evaluated in 53 children treated from 1991 to 1996 in 2 successive studies of IFN alfa therapy for severe hemangiomas at Sainte-Justine Hospital. Toxicity was generally mild and transient, with grade 1 toxicity occurring in 100% of patients, grade 2 toxicity in 89%, grade 3 toxicity in 58%, and grade 4 toxicity in 17%. Ten of 43 patients available for evaluation had an abnormal neurologic examination. Severe neurotoxicity in the form of spastic diplegia occurred in one patient. In conclusion, IFN alfa therapy is generally well tolerated in children. However, it may rarely be associated with severe toxicity and must be used with caution.

RASA1 mutations and associated phenotypes in 68 families with capillary malformation-arteriovenous malformation

Capillary malformation–arteriovenous malformation (CM–AVM) is an autosomal‐dominant disorder, caused by heterozygous RASA1 mutations, and manifesting multifocal CMs and high risk for fast‐flow lesions. A limited number of patients have been reported, raising the question of the phenotypic borders. We identified new patients with a clinical diagnosis of CM–AVM, and patients with overlapping phenotypes. RASA1 was screened in 261 index patients with: CM–AVM (n = 100), common CM(s) (port‐wine stain; n = 100), Sturge–Weber syndrome (n = 37), or isolated AVM(s) (n = 24). Fifty‐eight distinct RASA1 mutations (43 novel) were identified in 68 index patients with CM–AVM and none in patients with other phenotypes. A novel clinical feature was identified: cutaneous zones of numerous small white pale halos with a central red spot. An additional question addressed in this study was the “second‐hit” hypothesis as a pathophysiological mechanism for CM–AVM. One tissue from a patient with a germline RASA1 mutation was available. The analysis of the tissue showed loss of the wild‐type RASA1 allele. In conclusion, mutations in RASA1 underscore the specific CM–AVM phenotype and the clinical diagnosis is based on identifying the characteristic CMs. The high incidence of fast‐flow lesions warrants careful clinical and radiologic examination, and regular follow‐up.

Pediatric hepatic vascular anomalies

Abstract The typical vascular anomalies (tumors and vascular malformations) that involve the liver in infants and children are summarized. Many of these lesions are complex and require multiple imaging modalities, often including angiography, for precise diagnosis.