Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02356887 |
| Other study ID # |
14-8319 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 2015 |
| Est. completion date |
September 2015 |
Study information
| Verified date |
December 2022 |
| Source |
University Health Network, Toronto |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
During neurosurgical procedures, patients need to be placed in sitting position for surgical
access especially in surgeries in the vertex or posterior fossa. Due gravitational effect of
sitting position the flow in IJV may be reduced. Venous air embolism (VAE) is a common
complication of sitting position craniotomy and carries high mortality and morbidity. Venous
pressure decreases as the head of the patient is raised above the heart. Hence, negative
venous pressure in the cerebral venous system promotes entrapment of air in accidental
opening of the sinuses.
Common methods to prevent VAE in sitting position include increasing the venous pressure by
either jugular venous compression and/or increasing the venous pressure by adding positive
end expiratory pressure (PEEP). Both these methods can decrease venous return and can lead to
brain swelling.. In addition, improper neck position can cause the kinking of the IJV which
may lead to decreased venous drainage and increased ICP. This has been shown to be the
contributing factor for intraoperative brain swelling and postoperative neck and tongue
swelling leading to airway obstruction. Optimal brain perfusion is best in the neutral
position of the head, but surgery cannot always be performed with this.
Description:
Currently, there are no studies that looked into the IJV flow in sitting position and effect
of venous outflow obstruction on the IJV flow. Valsalva maneuver (forced inspiration with
closed glottis) and /or compression of internal jugular veins (IJV) are the two commonly used
physiological methods that can cause venous outflow obstruction. A custom made neck collar
can be used for compression of internal jugular vein and previous investigations have used a
similar device in a rat model to demonstrate the protective effects on slosh-mediated brain
injury by increasing intracranial blood volume . While the collars have not yet been studied
on people for their effectiveness at preventing concussions, many studies have looked at the
effect of neck collars on both jugular compression and ICP..
The purpose of this study is to measure the venous blood flow of healthy volunteers by the
use of an ultrasound and Doppler velocimetry in sitting position. the investigators will
measure the IJV flow on both sides in sitting position at rest and at two conditions of
venous outflow obstruction- 1. Neck compression using a custom made collar and 2. During 30
seconds Valsalva maneuver. This study will provide information on the cerebral venous
drainage. This information will be very useful in planning and positioning of patients
undergoing neurosurgical procedures and to prevent complications from the improper patient
position.