Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: How difficult can it be to transplant a spinal cord?

  1. #1
    Senior Member
    Join Date
    Jun 2005
    Location
    Norway
    Posts
    17,427

    Question How difficult can it be to transplant a spinal cord?

    I was thinking since we today have donors and transplantations of a variety of organs, wouldn’t it also be possible to transplant parts of spinal cords?

    Could one approach to fixing spinal cords involve transplanting spinal cord tissue from a donor to a spinal cord injured person?

    Say if we have a T4-T5 spinal cord chronic injury with some millimetres or for that matter some centimetres with damaged spinal cord.

    - Would it be possible to take a donor spinal cord from a person whom are in the process of dying and perform surgery on that person by disconnecting the arteries and veins for a part of the spinal cord and keep it artificial alive by blood pumping machines etc.

    And then take a chronic spinal cord person and perform laminechtomy on this person and also remove the scare tissue in the spinal cord itself where the damage is and then transplant the donor part spinal cord into this site and hook-up the blood vessels.

    I know that researchers can grow and keep nerves in a Lab so keeping a part of a spinal cord alive should also be possible, at least for a few minutes.

    As I understand for spinal cords as well the rejection of other tissue is also minimal due to little blood contact in the cord itself. Of course the patient must be on rejection drugs after the surgery like many other transplanted due to the blood vessels also transplanted.

    Also during this transplanting process the spinal cord injured person can recive stem cell and other treatements as for acute injuries. Like some of the treatments they want to start with these days for acute injuries.

    Can this scenario become a reality in the future? Why not?

    Leif

  2. #2
    Senior Member DA's Avatar
    Join Date
    Jul 2001
    Location
    beaumont tx usa
    Posts
    32,389
    Quote Originally Posted by Leif
    I was thinking since we today have donors and transplantations of a variety of organs, wouldn’t it also be possible to transplant parts of spinal cords?

    Could one approach to fixing spinal cords involve transplanting spinal cord tissue from a donor to a spinal cord injured person?

    Say if we have a T4-T5 spinal cord chronic injury with some millimetres or for that matter some centimetres with damaged spinal cord.

    - Would it be possible to take a donor spinal cord from a person whom are in the process of dying and perform surgery on that person by disconnecting the arteries and veins for a part of the spinal cord and keep it artificial alive by blood pumping machines etc.

    And then take a chronic spinal cord person and perform laminechtomy on this person and also remove the scare tissue in the spinal cord itself where the damage is and then transplant the donor part spinal cord into this site and hook-up the blood vessels.

    I know that researchers can grow and keep nerves in a Lab so keeping a part of a spinal cord alive should also be possible, at least for a few minutes.

    As I understand for spinal cords as well the rejection of other tissue is also minimal due to little blood contact in the cord itself. Of course the patient must be on rejection drugs after the surgery like many other transplanted due to the blood vessels also transplanted.

    Also during this transplanting process the spinal cord injured person can recive stem cell and other treatements as for acute injuries. Like some of the treatments they want to start with these days for acute injuries.

    Can this scenario become a reality in the future? Why not?

    Leif

    if a doctor perform that surgery, the doctor will only be giving a person paralysis with another person spinal cord.

    How would you connect that cord to the brain?
    when you figure that part out, no need to transplant another cord, just use that techique on your old cord.

  3. #3
    Senior Member
    Join Date
    Jun 2005
    Location
    Norway
    Posts
    17,427
    Quote Originally Posted by DA
    if a doctor perform that surgery, the doctor will only be giving a person paralysis with another person spinal cord.

    How would you connect that cord to the brain?
    when you figure that part out, no need to transplant another cord, just use that techique on your old cord.
    DA,
    I was not talking about transplanting the whole cord of course. I was talking about transplanting a little piece of tissue with its blood vessels from a donor. Transplant this little piece of spinal cord tissue with its neurons and blood vessels into a damaged site to a person with a spinal cord injury. And then my point was to use the acute cure techniques we have today to hook-up and connect this transplanted piece with the patient’s spinal cord.

  4. #4

    Cool

    Leif, awakening idea to researchers

  5. #5
    Leif,

    There are three reasons why transplanting parts of the spinal cord is not a particularly good solution to human spinal cord injury.

    1. You have the ensure the survival of the transplanted cord. This requires the connection of the blood supply of the transplanted tissue to the existing blood supply. Because the blood supply to the spinal cord is limited, there is a dearth of available blood supply. Yes, one might be able to vascularize the piece of spinal cord to be transplanted by first placing it in the omentum and allowing the omentum vessels to enter the spinal cord and then transplanting the vascularized spinal cord with a pedicularized flap. However, neurons cannot survive longer than 10-20 minutes without blood flow and vascularization of the cord by omentum takes 12-24 hours at the fastest. Oxygen cannot diffuse further than about 500 µmeters (0.5 mm) and it is not possible to keep the tissue oxygenated even in a hyperbaric oxygen chamber. By the way, the way that other organs such as heart, lung, kidney, and liver can be transplanted is by directly connecting artery to artery and vein to vein. It might be possible to transplant a brain (and the russians have done that in animals).

    2. The transplanted spinal cord must be connected to the existing brain and spinal cord. This is easier said than done. If one could actually do that, one should be able to regenerate the spinal cord.

    3. Motoneurons in the transplanted cord (if they survive the transplant) have to grow out of the spinal cord through the roots, into the peripheral nerves, and innervate muscle. Likewise, sensory axons from the dorsal root ganglia have to be preserved, reconnected to the spinal roots, enter the spinal cord, regenerate to the brain, and make connections to both the brain and the spinal cord.

    I am sorry that I don't have time to answer this question is greater detail but if you have any questions about the above, please ask.

    Wise.

  6. #6
    This made me think of the head transplant research that was being suggested in cases of severe paralysis. Remove the head of a quad and attach it to a healthy body. And while the experiments in rhesus monkeys were successful as far as restoring blood flow and keeping the brain/body viable and functional, the researcher was unable to restore the communication pathways between the new brain and the spinal cord. As Dr. Young pointed out, if that hurdle could be overcome we could cure paralysis and head transplants or in this case cord transplants, wouldn't be necessary.
    Last edited by antiquity; 01-13-2006 at 02:12 PM.

  7. #7
    Senior Member
    Join Date
    Jun 2005
    Location
    Norway
    Posts
    17,427
    Seneca thanks, but you are moving to fast here. I was only discussing to transplant a little piece of spinal cord tissue with its capillaries into the part where a person has an injured site and also lacks this part of the cord. Just tissue transplantation where a person lacks some parts of his/here cord. Say for instance where a person has a hemispheric cut to the cord. Because you have to replace the missing or damaged part of a cord with something, in this example I suggested to transplant some cord tissue and use acute experimental techniques to connect it i.e. stem cells.

    And, thanks Wise, I’ll see if I can come up with more questions although I understands you are very busy these days.
    Last edited by Leif; 01-13-2006 at 09:11 AM.

  8. #8
    If I remember the thread correctly, a team of Japanese surgeons were able to remove one section of the cord from one mouse to the other with very little motor and sensory loss.

  9. #9
    I think that it was in early 1990's, at a Bermuda Conference, that I heard Geoffrey Raisman give a talk in which he pointed out the arrogance of Western scientists who propose to "bridge" the spinal cord, by cutting a piece out and replacing it with another. In 1994, Saburo Kawaguchi did do this by cutting out a piece of spinal cord and then placing that piece back. He successfully did that in neonatal (newborn) rats. Published in Nature, that paper intrigued me and I went over to Kyoto for three days to see how he did it. He cut the piece out with a really sharp knife and placed it back in. Over the subsequent 10 years, he tried very hard to replicate this feat in adult rat spinal cords. He was able to do so only in a few animals, finding that the trick was to place fetal astrocytes (probably precursor cells and possibly some neural stem cells) into the interface. His theory was that if you provide a path for the axons to grow (and he believed that astrocytes provided that path), the axons will regenerate across both sides of the interface. Unfortunately, Kawaguchi's work was controversial and nobody has yet succeeded in replicating his original work except in his laboratory. I examined the serial sections of the spinal cords and was convinced that he did it. He also demonstrated it for me in neonatal rats. The main problem with doing it in adult rats is that the spinal cord would shrink away from the cut edges and he had to remove a whole vertebral body in order to create the slack necessary to bring the cut edges together. It was quite invasive surgery and it was very difficult to do in rats. Kawaguchi did not believe that myelin-based axonal growth inhibitors such as Nogo played a major role in stopping axonal growth. His theory is that within 72 hours of injury, axons must be provided a path to grow and, if they don't find that path, they will go into the sprouting or search mode where they will just grow short distances and connect with neurons that are close by. However, if they find that path, they will grow and keep growing in large numbers, forming spinal tracts. In any case, this is still far from being applicable to human spinal cords. As you can imagine, there are a number of critical surgical problems that need to be solved.

    Wise.

    Quote Originally Posted by Leif
    Seneca thanks, but you are moving to fast here. I was only discussing to transplant a little piece of spinal cord tissue with its capillaries into the part where a person has an injured site and also lacks this part of the cord. Just tissue transplantation where a person lacks some parts of his/here cord. Say for instance where a person has a hemispheric cut to the cord. Because you have to replace the missing or damaged part of a cord with something, in this example I suggested to transplant some cord tissue and use acute experimental techniques to connect it i.e. stem cells.

    And, thanks Wise, I’ll see if I can come up with more questions although I understands you are very busy these days.

  10. #10
    Also, in an adult spinal cord, I believe that the trauma of cutting out scar tissue or sections of cord would just lead to the development of more scar tissue.

Similar Threads

  1. Replies: 3
    Last Post: 03-11-2005, 11:16 PM
  2. Replies: 24
    Last Post: 11-15-2004, 09:50 PM
  3. Replies: 18
    Last Post: 01-12-2004, 10:04 AM
  4. Replies: 13
    Last Post: 11-04-2003, 10:56 AM
  5. Omentum transplant for spinal cord injury
    By Wise Young in forum Clinical Trials
    Replies: 2
    Last Post: 01-17-2002, 11:00 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •