effects of head rotation

Cece · Post by **Cece** » Tue Jul 19, 2011 11:12 am

http://onlinelibrary.wiley.com/doi/10.1 ... 209.x/full

We investigated the effects of head rotation on the cross-sectional area of the right internal jugular vein and its relative position to the carotid artery. Eighty-eight subjects were divided into infants and children groups. The cross-sectional area of the right internal jugular vein and the degree of the carotid artery overlap were measured at 0° (neutral), 40° and 80° of head rotation. The cross-sectional area of the right internal jugular vein was significantly larger at 40° and 80° head rotation compared with the neutral position in both infants and children (p < 0.001). As the head was rotated, the percentage overlap of the carotid artery increased significantly (p < 0.001). We suggest that 40° head rotation appears to be optimal for right internal jugular vein cannulation in paediatric patients.

Presumably as the right jugular is getting bigger, the left is getting smaller. But this may explain why I did better when looking to the right for long periods than if I had to look to the left. My left jugular was entirely useless (99% stenosed) so looking to the right increased the size of my right jugular?

PCakes · Post by **PCakes** » Tue Jul 19, 2011 11:29 am

Hi

Would the Left IJV decrease in size or remain patent?
This article reminds me of a long ago discussion here regarding 'stomach sleepers' and wether this habit is detrimental to blood flow.

Cece · Post by **Cece** » Tue Jul 19, 2011 11:50 am

PCakes, I don't even know. I am not sure if it is discussing the jugulars when supine or upright?

Another article:
http://journals.lww.com/anesthesiology/ ... us.36.aspx

Discussion

The development of severe neurologic dysfunction after surgery and anesthesia is rare in children and typically results from hypoxia, emboli, or hemorrhage in children with congenital heart abnormalities. The neurologic complication described here, however, occurred in a child without cardiac disease, and in the absence of hypoxia. The child was hypotensive for a 1-h period, but the recorded low blood pressure (50-70 mmHg) alone would not be expected to produce global cerebral ischemia. The complication seen in this child is thought to be the result of bilateral jugular venous occlusion combined with hypotension. The left IJV was occluded by the catheter-sheath in combination with a pressure dressing, whereas the right IJV was compressed after neck rotation by the invisible subcutaneous loop of the Broviac catheter.

Blood drains from the brain by two major routes: the jugular veins and vertebral venous plexus. The vertebral venous plexus is a major source of cerebral venous drainage only in the upright position, [1,2] and it is generally assumed that in the supine position, the jugular veins are the main cerebral venous drainage routes. It has been shown in animals that ligation of IJVs affects venous return from the cranial cavity and results in intracranial hypertension. [3] Similar events have been seen in humans. [4-6] It is likely that impairment of venous outflow is the main cause of these abnormal changes within the cranium. Further, impairment of venous return is likely to influence the reabsorption of cerebral spinal fluid possibly contributing further to intracranial hypertension and edema. [7] In the supine position, head rotation alone has an effect on IJV flow and increases the intracranial pressure (ICP), particularly with rotation 90 [degree sign] to the right. Because the left IJV often is smaller than the right IJV, there is a greater increase in ICP with head rotation to the right in patients with a baseline ICP greater than 10mmHg compared with that on head rotation to the left. [1,8] Studies using the range-gated Doppler technique have shown that rotation of the head 90 [degree sign] to the side completely obstructs jugular venous flow on that side. [8] Early recognition of jugular venous obstruction is necessary to avoid progressive cerebral injury.

I can comment on this later, but I bolded some of what seemed relevant. This was a tragic situation where a child undergoing abdominal surgery had both jugulars obstructed.

Cece · Post by **Cece** » Tue Jul 19, 2011 12:03 pm

http://www.sciencedirect.com/science/ar ... 8201902252

The effect of head rotation on the diameter of the internal jugular vein: implications for free tissue transfer

Joseph Kamal Muhammada, f1, Neil David Pughb, Lucy Bodenb, St John Creana and Michael John Fardya

a Department of Maxillofacial Surgery, (Head: Professor, J. P. Shephera BDS MSc DDSc PhD FDSRCS), University Hospital Wales, Cardiff, UK

b Medical Physics and Bioengineering, (Head: Professor J. P. Woodcock BSc MPhil PhD CPhys FInstP, FIPEM, OBE), University Hospital Wales, Cardiff, UK

Received 16 June 2000; accepted 16 May 2001. ; Available online 12 March 2002.

Abstract
Purpose: To determine the effects of medial (inwards) and lateral (outwards) rotation of the head on the transverse diameter of the internal jugular vein. Material: The original study sample included 26 patients. Duplex ultrasound was used to measure the transverse diameter of the internal jugular vein at a fixed point on either side of the neck. Measurements were taken with the head central (neutral position), rotated laterally and medially. Results: Using Student's t -test we found that lateral rotation of the head produced a reduction in the mean of the transverse diameters of the left and right ipsilateral vein from 6.9 mm to 5.4 mm (p<0.03) and 5.9 mm to 5.0 mm (p=0.2173) respectively. One patient excluded from the study because of previous neck surgery showed complete occlusion of the ipsilateral internal jugular vein on lateral rotation of the head.
Conclusion: There is a possibility that patency of the vein could be compromised if the head is turned laterally. This situation may arise immediately after surgery in the ventilated and paralysed patient when the head may be unsupported. It could be of particular importance if the vein has been used as a recipient vein for free tissue transfer.

civickiller · Post by **civickiller** » Tue Jul 19, 2011 12:20 pm

Cece wrote: It is likely that impairment of venous outflow is the main cause of these abnormal changes within the cranium. Further, impairment of venous return is likely to influence the reabsorption of cerebral spinal fluid possibly contributing further to intracranial hypertension and edema.

sorry i deleted the part that quotes cece's quote of the article

i wish i could see where and how these impairments are in the veins

Cece · Post by **Cece** » Tue Jul 19, 2011 12:27 pm

In that particular case, it was due to external factors. Catheters or sheaths got wrapped around the IJV on one side and compressed it on the other side. It had a tragic outcome, the little girl died because of it.

Cece · Post by **Cece** » Tue Jul 19, 2011 12:39 pm

www.ajnr.org/cgi/content/abstract/4/6/1219

American Journal of Neuroradiology, Vol 4, Issue 6 1219-1221, Copyright © 1983 by American Society of Neuroradiology

--------------------------------------------------------------------------------

ARTICLES

Effect of head turning on blood flow in lateral sinuses of nonhuman primates
TO Gabrielsen, LG D'Alecy, JE Knake, PG Hildenbrand and SS Gebarski

The pattern of blood flow leaving the cranium via the lateral sinuses and internal jugular veins is significantly altered by head rotation. This effect is documented in the baboon and macaque monkey by Doppler flow recording and by angiography. This phenomenon may affect the validity of cerebral blood flow data determined by venous sampling and may have significance in angiographic interpretation and in the clinical course of patients with a hypoplastic or occluded lateral sinus or internal jugular vein.

Cece · Post by **Cece** » Tue Jul 19, 2011 12:44 pm

http://www.ncbi.nlm.nih.gov/pmc/article ... 5-0077.pdf

Rotation of the head to one side causes obstruction
of the ipsilateral internal jugular vein in most
anaesthetized and many nonanaesthetized children,
and may cause intracranial venous stasis.

This looks like an old piece of research. But there you go...turn the head to the right and it will open up that vein (as seen in the first bit of research posted above) and obstruct the other vein. If the other vein is already fully obstructed, as it was in my case or in the case of anyone who has lost a vein due to complications of CCSVI treatment, there is a benefit to be had in turning the head in the direction of the remaining vein.

Cece · Post by **Cece** » Tue Jul 19, 2011 3:31 pm

Another thought is that, if I want to maximize the flow in my left jugular so that it heals better and does not restenose, I should look to the left as much as possible?

pklittle · Post by **pklittle** » Tue Jul 19, 2011 4:50 pm

I thought our internal jugulars were used only when you lie down. When upright, they are basically collapsed, right?

Cece · Post by **Cece** » Tue Jul 19, 2011 5:38 pm

You're right. So the head rotation issues would be when lying down.

There are people who have that particular Zamboni criteria where they have a greater area measurement of the internal jugular vein when upright than when lying down (due to blockages of the azygous or verts, perhaps?). Then head rotation would be relevant when upright.

One of these articles also talked about rotation having an effect on the flow out of the sinuses but I don't see why that would happen.

scorpion · Post by **scorpion** » Tue Jul 19, 2011 6:33 pm

Wow. This thread is making my head spin!

Cece · Post by **Cece** » Tue Jul 19, 2011 6:41 pm

lol, scorpion, but are you upright or supine while you are spinning?

Motiak · Post by **Motiak** » Wed Jul 20, 2011 3:02 am

This isn't entirely related but I know if I tilt my head back and then tilt it back forward to look straight I get hit by a wave of nausea and vertigo. I've wondered for a while if it's related to CCSVI or if it's just some random other MS crap that I've picked up along the way.

Cece · Post by **Cece** » Wed Jul 20, 2011 7:01 am

Could be, Motiak. Temporary cerebral congestion after that specific maneuever....

http://www.medscape.org/viewarticle/522597_3

Valdueza and colleagues[45] used color-coded duplex sonography to measure cerebral venous outflow in 23 healthy human volunteers, and found that internal jugular flow decreased from 700 mL/minute in the supine position to 70 mL/minute at 90° elevation. They also found a corresponding increase in vertebral vein flow from 40 mL/minute at 0° elevation to 210 mL/minute at 90°, with the remainder of the unmeasured flow probably passing through the internal vertebral venous plexus, which was inaccessible to Doppler measurement.

If the jugular flow is 70 ml/min when upright, they are not altogether collapsed.