Access strategies for revision or explantation of the Charite lumbar ADR

[Justin]

Journal of Vascular Surgery. 44(6):1266-72, 2006 Dec.

Access strategies for revision or explantation of the Charite lumbar artificial disc replacement.

Wagner, Willis H. Regan, John J. Leary, Scott P. Lanman, Todd H. Johnson, J Patrick. Rao, Rajeev K. Cossman, David V.

Division of Vascular Surgery, Cedars-Sinai Medical Center and Century City Doctors Hospital, Los Angeles, CA 90048, USA.

BACKGROUND: Several lumbar disc prostheses are being developed with the goal of preserving mobility in patients with degenerative disc disease. The disadvantage of lumbar artificial disc replacement (ADR) compared with anterior interbody fusion (ALIF) is the increased potential for displacement or component failure. Revision or removal of the device is complicated by adherence of the aorta, iliac vessels, and the ureter to the operative site. Because of these risks of anterior lumbar procedures, vascular surgeons usually provide access to the spine. We report our experience with secondary exposure of the lumbar spine for revision or explantation of the Charite disc prosthesis. METHODS: Between January 2001 and May 2006, 19 patients with prior implantation of Charite Artificial Discs required 21 operations for repositioning or removal of the device. Two patients had staged removal of prostheses at two levels. One patient had simultaneous explantation at two levels. The mean age was 49 years (range, 31 to 69 years; 56% men, 42% women). The initial ADR was performed at our institution in 14 patients (74%). The mean time from implantation to reoperation was 7 months (range, 9 days to 4 years). The levels of failure were L3-4 in one, L4-5 in nine, and L5-S1 in 12. RESULTS: The ADR was successfully removed or revised in all patients that underwent reoperation. Three of the 12 procedures at L5-S1 were performed through the same retroperitoneal approach as the initial access. One of these three, performed after a 3-week interval, was converted to a transperitoneal approach because of adhesions. The rest of the L5-S1 prostheses were exposed from a contralateral retroperitoneal approach. Four of the L4-5 prostheses were accessed from the original approach and five from a lateral, transpsoas exposure (four left, one right). The only explantation at L3-4 was from a left lateral transpsoas approach. Nineteen of the 22 ADR were converted to ALIF. Two revisions at L5-S1 involved replacement of the entire prosthesis. One revision at L4-5 required only repositioning of an endplate. Access-related complications included, in one patient each, iliac vein injury, temporary retrograde ejaculation, small-bowel obstruction requiring lysis, and symptomatic, large retroperitoneal lymphocele. There were no permanent neurologic deficits, deep vein thromboses, or deaths. CONCLUSIONS: Owing to vascular and ureteral fixation, anterior exposure of the lumbar spine for revision or explantation of the Charite disc replacement should be performed through an alternative approach unless the procedure is performed < or = 2 weeks of the index procedure. The L5-S1 level can be accessed through the contralateral retroperitoneum. Reoperation at L3-4 and L4-5 usually requires explantation and fusion that is best accomplished by way of a lateral transpsoas exposure.

[mmglobal]

Justin, thanks for the post... Great find!

This is a very interesting topic and one that we're all concerned with as we make our decisions about ADR. The perception of revisability of ADR has changed over the years. When I first started researching, we said, "No problem, try ADR and if it doesn't work, they can pop it out and fuse... no harm, no foul."
Later, ADR naysayers screamed gloom and doom, "NOT REVISABLE !" I can't tell you how many times I've read about doctors saying that there is a 25% chance of dying in a lumbar ADR revision surgery.

The truth lies somewhere in the middle.

If you need ADR surgery you are already in trouble. If you need revision surgery, you have even more trouble. Sadly, I know way too many people who have or will need revision surgery. I still believe in the technology and while I know many horror stories, I see the successes as well. For the most part the stories are good. However, I know people who are excellent candidates going to the top surgeons in the US and worldwide, who still have poor outcomes and have faced or will face revision surgery. About 1/3 of the people in the study Justin posted are people that I know very well. I can't describe how horrific the ordeal can be. Failed surgery... ongoing pain or serious complications... revision surgery and in some cases, multiple revision surgeries... and in some cases, complications from the revision. You'll note the reference to 'staged removal'. What this means is failed 2-level ADR followed by serious complications at one of the levels. All indications are that the remaining good level is OK and there is no reason to revise. Months later, the remaining ADR has a problem and there is third surgery. The patient has taken 18 months and 3 serious surgeries to arrive at the 2-level fusion she was trying to avoid in the first place.

The presentations I've seen and discussions I've participated in through the years have always revolved around the ability to mobilize the great vessels enough to have access to remove a prosthesis, and even more difficult to gain enough room to insert another prosthesis if that is the plan. Obviously, as we read in the article, there are other issues that are significant as well, but the big scare has to do with the great vessels. Keeled devices make the difficulties much, much worse. L5-S1 is easiest because it's almost always well below the bifurcation of the great vessels. L3-4 is next because it's usually well above the bifurcation. L4-5 is usually the most problematic because it's normally at (behind) the bifurcation. The great vessels come down from the heart and split into the branches that go down each leg. With the first surgery, they are easy to move. After the first surgery, they become 'scarred down' and are stuck to surrounding tissues by scar tissue that forms. Some ADR surgeons reduce the risk of future revision surgery by putting a barrier between the vessels and the tissue below. Since the incidence of revision surgery, especially with the surgeons that are that careful, is so low, that there is not much data on how effective the various barriers are.

Based on what I know from discussing this extensively over many years with some of the most experienced ADR surgeons in the US and overseas, I believe that the risks of revision surgery are nowhere as horrific as the gloom and doom folks would have us believe. It's also not nearly as good as they say. I know people with revisions by very experienced surgeons who still have serious complications.

A non-keeled device will be easier to remove than a keeled device because the surgeon can distract the disc space, break the plates loose from the vertebral bodies and take them out obliquely. They do not need to move the great vessels all the way out of the way if they can remove the prosthesis out the side... not straight out the front. Charite' will be easy because they can remove the core and deal with each plate individually. Flexicore will be difficult because of the height and it's all a unit...upper and lower elements (and the joint) must come out as one. However, since the Flexicore has no keel, I believe it can be removed from an oblique angle. ProDisc may also be removed obliquely even with a keel... after the core is removed and plate is broken loose, there should be enough distraction to allow enough clearance for the plate and the keel so it can be taken out from an angle instead of having to slide out straight out the front. However the Maverick with it's all metal design is problematic here. Because it's only a 2-piece device, there is no removing the core to have extra room to work with. Because the height of the keel, and the total height of the prosthesis, there is no reasonable way to provide enough distraction to allow the prosthesis to be taken out from an oblique angle. You cannot move the keel sideways through the vertebral body! The surgeon will need to either provide enough access to remove the prosthesis straight out the front, or she must seriously damage the vertebral body in an effort to remove it from an angle. IMHO, revisability issues are a showstopper when considering implanting a Maverick at L4-5. If there is a problem, taking it out will be much riskier than any of the other prostheses.

As with implantation, surgeon's experience and skill are paramount. Revision surgery is rare and complicated. Going to someone with great experience with revision may be even more important than with other surgeries... I believe that many patients revised in the US had surgical strategies that were dictated by clinical trial issues and the surgeons coming to grips with revisions issues without the benefit of ADR revision experience.

We all hope that we won't need revision surgery and I believe that the odds are in our favor. But, even if it's a 1% revision rate, that's still a lot of revision surgeries that will be needed, so these are important issues. I wish that I didn't know so many ADR revision patients, but I do. Each case is unique and the patients are presented with few options... all bad. If you are considering revision, please feel free to call me and I'll share what I know. I hope my phone never rings.

Mark

PS Remember... I'm not a doctor... Just sharing my perceptions of the things I've learned through the years... could be completely wrong...

[ans]

Great posting Dr. J. and similar read Mark.

Let's say I have a ProDisc at L4-L5. If re-entry was needed, could that happen at this level? Also, would the keel be snapped off and to what degree would this destroy the vertebral body itself? My sense is that a lateral approach works with most areas other than L5-L5 (dim memory re: discussion w/Dr. Regan).

Thanks, Allan

[mmglobal]

Allan... I don't think there is any reasonable way to snap the keel off. The plate is one piece, cobalt chome.... not breaking. Various lateral approaches would be for removal of prosthesis but not to consider reimplantation of the current crop of devices... must be done from the front. As I write this, I do know doctors who are developing implantation techniques that allow lateral approach for total disc replacement. Also, there are keeled devices that have adjustable or selectable keel angles to allow oblique or lateral implantation once the approach has been developed. Imagine the geometry of implanting a keeled device from an angle. The keel cut must be perfect and there is only one place where midline placement intersects the a/p (anterior/posterior) placement of the device. That is where it will be without regard to endplate shape, tension, etc... no latittude in adjusting placement there. I usually see fine-tuning placement based on unique confuguration that is achieved after initial placement.

I can't really speculate about what might happen in revising ProDisc at L4-5. I know surgeons who do it without difficulty. I know surgeons who would not even try that technique and will elect to do a procedure that they perceive to be less risk in spite of more damage done. Also, once you get into revision surgery, each case is unique. I do beleive that we must go into our initial ADR surgeries expecting success and revisions issues, while important, are not paramount. I would not take a fusion instead of ADR because revising ADR may be difficult or risky. Revising failed fusion is risky too, for other reasons, but once you are having a revision, your life is on the line no matter what is being done. There are overriding concerns about the different disc designs in particular configurations that outweigh other issues. Our problem in trying to be informed patients is that we get so much conflicting information from very convincing sources. It is tough for us to know how much weight to assign to the different issues.

Mark

[Blairsara]

I love the fact that I'm lucky number 4 in my study with Dr. Regan to have the revision. And I think only 1, maybe 2 had to get the revision because of facet joint complications. I think I might be the only one who didn't have facet joint problems before my ADR. Dr. Regan gave me the article when we decided that revision surgery was the only thing left to do. It's pretty interesting stuff.

Blair

[Tim]

Hi
I've considered the issues surrounding re-entry following a previous anterior approach for some time.
I don't personally need to remove one of my ADR's but I am considering fusion of my L4/5 which is currently sandwiched between 2 supposedly functioning ADR's at L3/4 and L5/S1. Because of a previous extensive posterior decompression surgery in 1988 I am keen to avoid another posterior surgery for fear of scar tissue forming around the nerve roots which necessarily need to be moved for a posterior access. I know the risks of a repeat anterior are potentially even more frightening for reasons concerning scar tissue and the major blood vessels.
Some time ago a fusion via a lateral transpsoas approach was suggested to me - in theory this avoids the risks to both the major blood vessels and nerve root damage. My research has subsequently led to an approach known as the XLIF - Extreme Lateral interbody Fusion. This sounds very similar if not identical to the approch suggested for me.
Recently I came across an article outlining the details of two cases of ADR device revision in which they used a minimally invasive extreme-lateral interbody approach to effect a safer access route, avoiding vascular structures and the creation of scar tissue. I thought those facing revision surgery might find this interesting - unfortunately the link is to a html version which lacks images but it is still understandable..
The link is as follows:
http://66.102.9.104/search?q=cache:O...nk&cd=12&gl=uk
I hope this works... if not let me know and I'll copy and paste the text.

You can read more about the XLIF technique regards fusion at the following links:
1. http://sutterroseville.org/news/pres...release_id=569
2. http://lajollaspine.com/stmi_lumb_xlif.shtml
3. http://www.floridahospitalmedicalnew...lth-id242.html
4. http://illinoisneurospine.com/_wsn/page11.html
5. http://www.devicelink.com/mddi/archive/04/10/012.html

If anybody has personal experience with this technique and/or if anybody knows any surgeons in the UK using this technique I'd love to hear from you.

Blair - I wish you good luck in you upcoming revision surgery.
All the best
Tim

[mmglobal]

Tim, I've seen Nuvasiv's MaXcess system demonstrated at a surgeon's conference... very impressive access created. It will be interesting to see if retrieval of a keeled device through an extreme or translateral procedure will be or has already been successful. Again, as these aproaches are tried and succeed... a handful of cases done by other surgeons does not make it a slam dunk for others. If you need revision surgery, you are in rare air.

Mark

[grima6]

Hi Mark

I was happily polishing the same table for the fifth time (as diversional therapy) teying not to think about my revision surgery in 11 days AND THEN..... I READ YOUR POST! Now I am pretty worried. Even though the info was great in explaining the ins and outs of revision surgery, the fact that I am one of the really problematic maverick keeled discs you talked about has got me shaking in my boots!!!! As an RN I know that there are Vascular risks with L5-S1 revision surgery but now I am more aware of why Australian Drs didn't want to take out my keeled disc. The Maverick comes with the largest keel. Lucky me!!
Oh Well gotta look on the bright side, any change is good and as many of ISPINE people know the biggest fear when going in for surgery is not paralysis it is NO CHANGE, then the same crap just keeps going on with no light at the end of the tunnel.

Keep your fingers crossed for me Mark, I may just be a great Maverick revision test-case afterall!

[acheybreaky]

Man oh man, am I glad I found this site. Thanks Dr. J for posting this study. I originally found this on another forum, but it disappeared. Unfortunately for me, I am needing redo surgery and this topic is very close to my heart. Thanks Mark for providing such excellent information. It looks like I've come to the right place, you'll be hearing from me soon. Wow, I'm the 4th one here considering an ADR redo. I think that the outcomes for ADR are pretty good. We are the unlucky ones. I've been reading the forums a long time, but never post. I'm going back to lurk mode, but I just wanted to say thanks to Dr. J, Mark and everyone else that contributes. Sometimes I feel like I don't know enough and never feel like I have anything important to say.

abHeart

[Blairsara]

AcheyBreaky,
What kind of artificial disc do you have? My revision surgery is scheduled for May 24th and I have charite. I hope you're not in as much of pain as I am. Hope you're doing well. Why are you considering doing a revision? Do you have problems with your facet joints? Was it the placement?

Blair

[Maria]

Dr J and Mark,
Thanks for the information re revision surgery. Keep posting more please..

[akh-47]

Originally Posted by mmglobal

Justin, thanks for the post... Great find!

This is a very interesting topic and one that we're all concerned with as we make our decisions about ADR. The perception of revisability of ADR has changed over the years. When I first started researching, we said, "No problem, try ADR and if it doesn't work, they can pop it out and fuse... no harm, no foul."
Later, ADR naysayers screamed gloom and doom, "NOT REVISABLE !" I can't tell you how many times I've read about doctors saying that there is a 25% chance of dying in a lumbar ADR revision surgery.

The truth lies somewhere in the middle.

If you need ADR surgery you are already in trouble. If you need revision surgery, you have even more trouble. Sadly, I know way too many people who have or will need revision surgery. I still believe in the technology and while I know many horror stories, I see the successes as well. For the most part the stories are good. However, I know people who are excellent candidates going to the top surgeons in the US and worldwide, who still have poor outcomes and have faced or will face revision surgery. About 1/3 of the people in the study Justin posted are people that I know very well. I can't describe how horrific the ordeal can be. Failed surgery... ongoing pain or serious complications... revision surgery and in some cases, multiple revision surgeries... and in some cases, complications from the revision. You'll note the reference to 'staged removal'. What this means is failed 2-level ADR followed by serious complications at one of the levels. All indications are that the remaining good level is OK and there is no reason to revise. Months later, the remaining ADR has a problem and there is third surgery. The patient has taken 18 months and 3 serious surgeries to arrive at the 2-level fusion she was trying to avoid in the first place.

The presentations I've seen and discussions I've participated in through the years have always revolved around the ability to mobilize the great vessels enough to have access to remove a prosthesis, and even more difficult to gain enough room to insert another prosthesis if that is the plan. Obviously, as we read in the article, there are other issues that are significant as well, but the big scare has to do with the great vessels. Keeled devices make the difficulties much, much worse. L5-S1 is easiest because it's almost always well below the bifurcation of the great vessels. L3-4 is next because it's usually well above the bifurcation. L4-5 is usually the most problematic because it's normally at (behind) the bifurcation. The great vessels come down from the heart and split into the branches that go down each leg. With the first surgery, they are easy to move. After the first surgery, they become 'scarred down' and are stuck to surrounding tissues by scar tissue that forms. Some ADR surgeons reduce the risk of future revision surgery by putting a barrier between the vessels and the tissue below. Since the incidence of revision surgery, especially with the surgeons that are that careful, is so low, that there is not much data on how effective the various barriers are.

Based on what I know from discussing this extensively over many years with some of the most experienced ADR surgeons in the US and overseas, I believe that the risks of revision surgery are nowhere as horrific as the gloom and doom folks would have us believe. It's also not nearly as good as they say. I know people with revisions by very experienced surgeons who still have serious complications.

A non-keeled device will be easier to remove than a keeled device because the surgeon can distract the disc space, break the plates loose from the vertebral bodies and take them out obliquely. They do not need to move the great vessels all the way out of the way if they can remove the prosthesis out the side... not straight out the front. Charite' will be easy because they can remove the core and deal with each plate individually. Flexicore will be difficult because of the height and it's all a unit...upper and lower elements (and the joint) must come out as one. However, since the Flexicore has no keel, I believe it can be removed from an oblique angle. ProDisc may also be removed obliquely even with a keel... after the core is removed and plate is broken loose, there should be enough distraction to allow enough clearance for the plate and the keel so it can be taken out from an angle instead of having to slide out straight out the front. However the Maverick with it's all metal design is problematic here. Because it's only a 2-piece device, there is no removing the core to have extra room to work with. Because the height of the keel, and the total height of the prosthesis, there is no reasonable way to provide enough distraction to allow the prosthesis to be taken out from an oblique angle. You cannot move the keel sideways through the vertebral body! The surgeon will need to either provide enough access to remove the prosthesis straight out the front, or she must seriously damage the vertebral body in an effort to remove it from an angle. IMHO, revisability issues are a showstopper when considering implanting a Maverick at L4-5. If there is a problem, taking it out will be much riskier than any of the other prostheses.

As with implantation, surgeon's experience and skill are paramount. Revision surgery is rare and complicated. Going to someone with great experience with revision may be even more important than with other surgeries... I believe that many patients revised in the US had surgical strategies that were dictated by clinical trial issues and the surgeons coming to grips with revisions issues without the benefit of ADR revision experience.

We all hope that we won't need revision surgery and I believe that the odds are in our favor. But, even if it's a 1% revision rate, that's still a lot of revision surgeries that will be needed, so these are important issues. I wish that I didn't know so many ADR revision patients, but I do. Each case is unique and the patients are presented with few options... all bad. If you are considering revision, please feel free to call me and I'll share what I know. I hope my phone never rings.

Mark

PS Remember... I'm not a doctor... Just sharing my perceptions of the things I've learned through the years... could be completely wrong...

Hi,
I know the above is an old post, but I am so glad i've found this forum. I had an SB Charite implanted at L5/S1 in 2003, and although things are good at the moment, I do realise that it may not be forever, so finding resources like this is invaluable.
I do have some questions to ask, and I'll do that at a later time, but first off I just wanted to say hi to everone.
Thanks and regards,
Andy

[dshobbies]

Hi Andy and welcome,

I look forward to learning more about your circumstances. When the time is right, please start a new thread and tell us about yourself. We're here to help and support each other.

Dale

[mmglobal]

Andy, welcome to he forum.

In the months since I wrote that post, I've observed a few ADR revisions. Some with, some without vascular complications.

Hopefully, you won't be needing revision surgery. I look forward to hearing more about your situation. Ask away!

Mark