MR Quantification of Flow in Children with Vein of Galen Malformations

SUMMARY

Vein of Galen vascular malformations are either Vein of Galen Aneurysmal malformations (VGAMs) or Vein of Galen Aneurysmal Dilatations (VGADs). VGAMs may be of the choroidal or mural type and are fistulas associated with the precursor of the vein of Galen. The treatment of VGAMs is aimed at controlling the size of the vascular shunt since it is believed that the shunt is responsible for venous hypertension, cardiac stress, delayed development and may be so large as to damage the brain. In VGAMs as noted by Berenstein and Lasjaunias. Absolute measures of flow may contribute to our understanding of CNS disease and permit objective measures of the success or failure of therapeutic interventions (5). MR phase contrast cine angiographic techniques can be employed to measure bulk flow in intracranial vessels. Vein of Galen vascular malformations are an ideal model to measure venous flow as the draining vein is large and angiographic evaluation is limited. Thus our goal was to develop an objective non-invasive method of measuring vascular flow in VGAMs and VGADs (6) . Herein we report our experience using this technique in a group of patients with Vein of Galen vascular malformations. We also hypothesized that the degree of shunting would correlate to the degree of cardiac stress and be an indicator of optimal timing for intervention. We believe that we have succeeded in our goal to develop an objective, non-invasive method of shunt quantification using velocity encoded MR sequences. This promises new insight into the hemodynamics, natural history and treatment response of vascular malformations.

Balloon pyloroplasty in children with delayed gastric emptying

OBJECTIVE

To evaluate initial experience with balloon pyloroplasty for delayed gastric emptying in children.

DESIGN

A retrospective review.

SETTING

A tertiary care pediatric hospital.

PATIENTS

Seven children with scintiscan-proven delayed gastric emptying that was refractory to maximal medical therapy.

INTERVENTIONS

Balloon pyloroplasty under fluoroscopic guidance, mostly on an outpatient basis. For 1 child, the procedure was endoscopically monitored also.

OUTCOME MEASURES

Postoperative symptoms and physical findings, gastric emptying and complications.

RESULTS

Of the 7 children who underwent balloon pyloroplasty, 3 were rendered asymptomatic and 2 more were symptomatically improved. Four of the original 7 patients underwent postdilation scintigraphy, and all 4 showed normalization of the gastric emptying time. There were no complications.

CONCLUSIONS

Initial experience with fluoroscopically-guided balloon pyloroplasty indicates that it is a safe and easily tolerated procedure, worthy of further study.

Treatment of recurrent hemoptysis in a child with cystic fibrosis by repeated bronchial artery embolizations and long-term tranexamic acid

The course of a 12-year-old girl with cystic fibrosis (CF) and with recurrent hemoptysis since age 8 years is described. Conservative measures failed to control her bleeding. Hemoptysis was only partially controlled by repeated bronchial arterial embolizations. However, the addition of tranexamic acid (TXA) resulted in complete cessation of bleeding. Attempts to withdraw TXA therapy resulted in recurrence of hemoptysis; this patient has, therefore, been continuously maintained on this therapy for the past 4 years. No side effects of long-term TXA treatment have been noted.

The role of ultrasound in evaluation of Takayasu's arteritis

Duplex ultrasound was used to assess the vascular status and predict the angiographic findings in 3 patients with Takayasu's arteritis. The most striking sonographic feature was the presence of concentric arterial wall thickening. Using pulsed Doppler, stenotic lesions were quantified, occlusive lesions were identified and collateral circulation was demonstrated. A high resistive flow pattern was demonstrated in diseased vessels compared with carotid wave-forms of control subjects. Subtle mural irregularity, minor stenotic lesions and areas of stenosis in branch vessels were missed by duplex evaluation. The thoracic aorta and occasionally major arterial branches in the abdomen were impossible to evaluate with ultrasound. Vascular magnetic resonance imaging was successful in delineating major aortic branches but was inferior to real-time ultrasound in resolving mural thickening. While angiography plays a major role as a baseline assessment of the entire vascular tree, duplex ultrasound can monitor disease progression and the effects of therapy. Serial duplex studies should greatly reduce the need for interval angiographic followup.

The development of a prosthesis for banding of an artery capable of staged dilatation by intraluminal balloon dilator: an experimental investigation

Two prostheses were developed that were capable of banding an artery and subsequently being dilated by an intraluminal balloon dilator inflated to six atmospheres. After a mean duration of 89 days, the banding was dilated successfully.

Early experience with arterial repair of transposition

Major anomalies associated with isolated complete transposition of the great arteries (TGA) can produce systemic pressure in the left ventricle without fixed stenosis of the left ventricular outflow tract. In this situation, arterial repair may be advantageous. Eight children, 10 days to 15 years old, underwent arterial repair of TGA. Major associated anomalies included large patent ductus arteriosus, bulging intraventricular septum, ventricular septal defect (VSD), tricuspid atresia, and the Taussig-Bing type of double-outlet right ventricle. There were 2 operative deaths related to acute left ventricular failure. The survivors underwent postoperative echocardiographic, hemodynamic, and angiographic assessment; all were in sinus rhythm and well six months to 2 1/2 years after operation. Residual lesions have been frequent but mild: aortic insufficiency (5), stenosis of the right ventricular outflow tract (1), trivial VSD (1), and stenosis of the right coronary artery (1). Left ventricular function is "normal" in 4 and unchanged from moderately depressed preoperative status in 1.

Acquired supravalvular aortic stenosis

Severe supravalvular aortic stenosis was discovered at reoperation in 3 children with recurrent stenosis of the left ventricular outflow tract. The lesion consisted of gross thickening of the sinus ridge, most marked at the site of the previous aortotomy. The thickening had shortened the free edge of one or more leaflets and had distorted adjacent commissures. Preoperative angiography had indicated valve stenosis, but little commissural fusion was found at operation and the outflow tract obstruction was relieved by inserting a prosthetic patch in the ascending aorta. Recognition of this iatrogenic pathology is important to avoid supravalvular stenosis after aortic valvotomy and unnecessary valve replacement in children requiring reoperation for recurrent left ventricular outflow tract obstruction.

The criss-cross and superoinferior ventricular heart: an angiocardiographic study

The angiocardiographic features of 11 patients with superoinferior and criss-cross type of atrioventricular (A-V) connections are presented. These unusual ventricular relations are thought to result from postseptation disturbances of ventricular looping. The angiocardiographic appearance of criss-cross is really an illusion, and the A-V connections among these patients are either concordant, discordant or straddling. The often small right A-V valve inflow and sinus portion of the ventricle, combind with the ventricular rotational anomaly, combine to give the angiocardiographic perception of criss-cross. A review of the 11 patients from this institution and those previously reported on suggests that most patients have a transposition of malposition of the great arteries; many have a small right ventricle, and about half have pulmonary outflow tract obstruction. In addition to the obvious embryologic, morphologic and clinical implications of these distorted ventricular loops, the criss-cross A-V hearts raise questions about the various segmental nomenclatures applied to these types of congenital heart disease.

The visibly fatty liver

Fatty infiltration of the liver has been identified roentgenographically in several young children. Awareness of this possibility will sometimes allow a radiologist to contribute to the understanding of the patient's metabolic and nutritional state. If a child's liver is shown to be abnormally radiolucent, cystic fibrosis should be considered.