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MR venography in children with complex craniosynostosis
N Rollins1, T Booth, K Shapiro
1Department of Radiology, University of Texas Southwestern Medical Center and Children's Medical Center, Dallas, Tex 75235, USA. nrolli@childmed.dallas.tx.us
Insights
Jugular foramen stenosis may cause hydrocephalus in complex craniosynostosis. MR venography (MRV) revealed venous outflow obstruction in most patients, with posterior condylar veins compensating for blocked jugular veins.
Area of Science:
- Neurosurgery
- Radiology
- Pediatric Neurology
Background:
- Complex craniosynostosis is associated with hydrocephalus and tonsillar herniation.
- Jugular foramen stenosis is a proposed cause of venous hypertension in these patients.
Purpose of the Study:
- To evaluate venous outflow obstruction using MR venography (MRV) in patients with complex craniosynostosis.
- To investigate the relationship between venous outflow obstruction, hydrocephalus, and tonsillar herniation.
Main Methods:
- Seventeen patients (4 months to 34 years) with complex craniosynostosis underwent MR imaging and axial 2D Time-of-Flight MRV.
- Patterns of venous drainage, hydrocephalus, and tonsillar herniation were assessed.
Main Results:
- Jugular vein obstruction was identified in 12 out of 17 patients, particularly in syndromic and non-syndromic cases.
- Posterior condylar veins were the primary collateral drainage pathway.
- Hydrocephalus was present in 75% of patients with abnormal MRV findings; tonsillar herniation was also frequently observed.
Conclusions:
- Posterior condylar veins play a crucial role in venous drainage during jugular bulb occlusion.
- While MRV can detect venous outflow obstruction, it may not always indicate significant intracranial venous hypertension.
Purpose:
Chronic venous hypertension due to jugular foramen stenosis has been proposed as an etiology for the hydrocephalus and tonsillar herniation seen in some patients with complex craniosynostosis. We report the use of MR venography (MRV) to evaluate venous outflow obstruction in this clinical setting.
Materials And Methods:
We studied 17 patients, (ages 4 months to 34 years; mean 7.3 years) with complex craniosynostosis; 8 patients with Crouzon's syndrome, 2 with Apert's, 1 with Pfeiffer's and 6 patients without an eponymous classification. MR imaging included routine imaging sequences and axial 2D TOF MRV. Patterns of venous drainage and the presence of hydrocephalus and tonsillar herniation were noted.
Results:
Jugular vein obstruction was seen in 12/17 patients; in 5/8 patients with Crouzon's, 1/2 with Apert's, the single patient with Pfeiffer's and 5/6 patients with nonsyndromic craniosynostosis. The predominant collateral drainage was via the posterior condylar veins. Nine of 12 (75%) of the patients with abnormal MRV had hydrocephalus; 3/8 patients with Crouzon's, 1/2 patients with Apert's, and 5/6 nonsyndromic patients. Two patients had hydrocephalus with normal MRV. Ten patients had tonsillar herniation, which was associated with shunted hydrocephalus in 7/10 patients, and hydrocephalus seen prior to shunt placement in 3/9. Nine of 10 patients with tonsillar herniation had an abnormal MRV, while 1 patient had a normal MRV. Venous pressures measured in 1 patient showed an 8-mm-Hg differential across the skull base.
Conclusions:
The posterior condylar veins appear pivotal in maintaining venous drainage when the jugular bulbs are occluded. Although the association between venous outflow obstruction, hydrocephalus and tonsillar herniation is intriguing, evidence of venous outflow obstruction by MRV may not be indicative of significant intracranial venous hypertension.