Radiofrequency technique poll

[specepic]

I would like to take an informal poll regarding the following parameters for your lumbar RFA technique. I have seen this done many ways (granted many of these end up with a similar needle position in the end)

Please specify:

- Fluoro angle (or lack thereof) e.g. "straight AP with superior endplate squared up" or "__ degrees caudal and __ degrees ipsi oblique tilt"

- Needle angle/technique e.g., down the barrel/coaxial advancement or advance out of plane by marking skin below or below/lateral to target

-optional info, needle size, use of steroid after burn, motor/sensory stim, use of AP, oblique/lateral

If you use U/S to guide your needles please mention that b/c that always gets a thread going

---

Members don't see this ad.

 

[specepic]

I will go first:

Where I trained we used pretty much a true AP (no angulation) and some attendings went down the barrel to the SAP/TP junction and some marked the skin below and lateral to that target and advanced out of plane. 18G needles. Some used steroids after burn. Some checked an oblique, everyone checked a lateral. All did motor, some did sensory. sedation for all. was seeing fair results with this in practice and needles often too posterior.

Now using a technique shown to me at ISIS course (not a lumbar RF course but the instructor had some extra time):

square up sup endplate, then tilt caudal about 30 degrees, then ipsi oblique 10 to 15 degrees for a nice (at least partial) scotty view and the groove of the SAP and TP shows up real nice, needle advanced in plane/down the barrel. Needles are def getting more (appropriately) anterior with this and sometimes also need to be withdrawn a bit once checked on lateral or based on motor stim. For the ala, this instructor squares up S1 endplate (which can make for quite a cephalad position), then backs off caudal 50 degrees from there. I have found this less helpful in that the fluoro angle is so flat that the needle tip does not always look ideal when checked in a standard AP so I readjust.

I also have stopped using steroids after burn which has increased post op calls of "that procedure did not work" while they wait for the effect.

 

[powermd]

I've adjusted my technique a bit over the two years since fellowship.

First I start full AP with the ala as the target. Skin entry just caudad and lateral to S1 foramen, advance to os contact near ala. Flip needle so it "lands" relatively tangential to the curvature of the ala. Adjust cephalad angulation to get a better view of how far over the top I am, then check oblique to see where I am relative to the S1 SAP/ala. Tends to get good stim quickly.

Next I move on to L5, and approach straight AP, with perhaps 5 degrees of ipsi oblique. On contact with bone, flip full ipsi oblique (to get a good view of the facet joint line and eye of the scotty dog). Adjust needle tip so again it rests tangential to the curvature of the SAP/TP groove. Provided I'm hugging the SAP, and not too lateral, this also tends to get good stim.

Same technique for L4 and above.

I do use steroid with my lido, haven't had any postop complaints.

Not to hijack, but I'd like to hear more about people's cervical techniques. I started doing these with a posterior approach (prone) after fellowship, and in AP view with some cephalad tilt (to get a reasonable view of the curvature of each lateral mass), I am to land the needle as flat as possible along this curvature. When I can see the curvature well, and have no trouble getting the skin entry point right to achieve a good trajectory, this works well. I run into trouble in patients where you can't see the lateral mass curvature well, or very skinny folks where the angle of approach is going to be very shallow. I've heard some talk about use a little contralateral oblique to see the lateral mass curvature better (and then wrapping the needle over the edge anteriorly), but I'd like to hear this integrated into a better "formula" for easily picking skin entry for ending up with optimal needle placement.

 

[bedrock]

I would like to take an informal poll regarding the following parameters for your lumbar RFA technique. I have seen this done many ways (granted many of these end up with a similar needle position in the end)

Please specify:

- Fluoro angle (or lack thereof) e.g. "straight AP with superior endplate squared up" or "__ degrees caudal and __ degrees ipsi oblique tilt"

- Needle angle/technique e.g., down the barrel/coaxial advancement or advance out of plane by marking skin below or below/lateral to target

-optional info, needle size, use of steroid after burn, motor/sensory stim, use of AP, oblique/lateral

If you use U/S to guide your needles please mention that b/c that always gets a thread going

I trained with strict ISIS technique although I've modified it slightly with more practice.

L5 nerve- 50 degrees caudal and 5-10 degrees ipsi oblique, but I tweak that slightly before needle insertion to ensure a crisp SAP/ala angle. Directing the needle down the beam aiming for the groove. Try to avoid bone until I'm close to SAP/ala angle. After striking bone close to SAP, I get AP to adjust depth and confirm that I'm hugging the SAP. Other views done simultaneously with other needles.

L4 nerve and higher- I'm already on the AP I just used for L5---then 15 degrees ipsi oblique and 30 caudal. Tweak both angles slightly before needle insertion to ensure crisp SAP/TP angle. Directing needle right down the beam aiming 1-2mm superior to groove while hugging the SAP. Once I strike bone I advance a couple mm, then get AP and adjust depth. Rarely also adjust medial/lateral if needed.

Go to lateral, make depth adjustments for all needles simultaneously, then back to AP. Test nerves and lesion at 85 degrees for 90 seconds. After first lesion, I withdraw the L5 needle slightly less than 1cm, while ensuring continued contact with bone. Then I return to my original view for the other nerves, (15 ipsi, 30 caudal) adjust so each needle is now in the groove, not 1-2mm superior to the grove they were for the first burn and then lesion a second time. Done.
ISIS standards for other-18g needle with 1cm curved active tip. No sensory stim, but do motor stim for safety, use 1-2cc of 2% lido at each nerve. No steroid after burn. Ridiculous to consider using US for spinal RF.

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

I used to get obliques on all my needles as that's how I was originally taught in fellowship. However, I've found that as long as I get a perfect crisp angle of the joint line with my original shot, the obliques aren't necessary. Occasionally I can't get a crisp initial SAP/SP joint line shot and for those patients I will check an oblique or two to ensure I'm right where I need to be. I also used to do separate cranial tilt view on L5 to confirm my depth, but now I just use the lateral for adjust the depth of all my needles at once.

 

[specepic]

when describing tilt, please specify from what initial position, e.g. if you state "30 degrees caudal" if that from AP to the table or AP in terms of a superior or inferior endplate being squared up. I suspect the latter but may be useful to clarify.

 

[epidural man]

I would like to take an informal poll regarding the following parameters for your lumbar RFA technique. I have seen this done many ways (granted many of these end up with a similar needle position in the end)

Please specify:

- Fluoro angle (or lack thereof) e.g. "straight AP with superior endplate squared up" or "__ degrees caudal and __ degrees ipsi oblique tilt"

- Needle angle/technique e.g., down the barrel/coaxial advancement or advance out of plane by marking skin below or below/lateral to target

-optional info, needle size, use of steroid after burn, motor/sensory stim, use of AP, oblique/lateral

If you use U/S to guide your needles please mention that b/c that always gets a thread going

Love the US comment.

I recently stopped using stim, only use motor.

There is no data to back up stim. Cohen is writing an article on this very thing right now.

As far as my technique, it depends - am I doing the procedure? Is the fellow? Is it bilateral? Am I doing one side and the fellow the other?

All that varies my technique a little.

 

[SSdoc33]

start in AP and place all the needles in AP. then confirm with oblique and laterals. no tilts. no "hub-o-gram" views. I start about an inch or 2 inferior and lateral to the targets but advance primarily in AP.

I used to do the cephalad tilt, advance in oblique, etc. but to be honest, i thought it was a wste of time and increased radiation. after a while, you get a sense of the appropriate angles and trajectories. at least i did. if anyting, my results have improved.

20 guage rf needles. no steroid

 

[caedmon]

For L5 dorsal ramus: Start AP. Cephalad tilt until I have a nice view of the Ala. Needle is inserted just a tad laterally to the ala and advanced down to os. Walk off superiorly, switch to ipsi oblique (15 degrees) and advance until the needle tip is at the anterior border of the S1 SAP.

Higher levels: Start straight AP with superior endplates squared off. Start needle trajectory about 2 inches inferior and 15 degrees lateral to the juncture of the SAP/TP (with significan hypertrophy this ends up being more lateral). Advance down to the juncture. Walk of slightly, then turn to 15 deg ipsi obllique and advance until you reach the anterior border of the SAP.

Once all needles are in place go lateral and ensure needle tips are just posteior to the foramen.

18 g curved tip

Steroid after burn. Is there a reason not to?

Motor stim only.

 

[specepic]

For L5 dorsal ramus: Start AP. Cephalad tilt until I have a nice view of the Ala. Needle is inserted just a tad laterally to the ala and advanced down to os. Walk off superiorly, switch to ipsi oblique (15 degrees) and advance until the needle tip is at the anterior border of the S1 SAP.

Higher levels: Start straight AP with superior endplates squared off. Start needle trajectory about 2 inches inferior and 15 degrees lateral to the juncture of the SAP/TP (with significan hypertrophy this ends up being more lateral). Advance down to the juncture. Walk of slightly, then turn to 15 deg ipsi obllique and advance until you reach the anterior border of the SAP.

Once all needles are in place go lateral and ensure needle tips are just posteior to the foramen.

18 g curved tip

Steroid after burn. Is there a reason not to?

Motor stim only.

The thought against steroid after a burn is that it may reduce your lesion/lesion size. I'm not sure if this has been studied....

 

[lobelsteve]

The thought against steroid after a burn is that it may reduce your lesion/lesion size. I'm not sure if this has been studied....

Sounds like nonsense. Burn is a burn. You are cooking a segment of tissue 10mm long and up to 2mm wide. Hopefully maximally placed parallel to a nerve.

Try this on yourself: numb and lesion an area on your skin x2. Apply steroid to one spot. Tell us if the burn gets smaller. Let's think like scientists.

 

[specepic]

Sounds like nonsense. Burn is a burn. You are cooking a segment of tissue 10mm long and up to 2mm wide. Hopefully maximally placed parallel to a nerve.

Try this on yourself: numb and lesion an area on your skin x2. Apply steroid to one spot. Tell us if the burn gets smaller. Let's think like scientists.

I hear you, but ISIS does not recommend steroid and I know many well respected ISIS instructors have strong feelings about it. I think a reasonable agrument is that while the steroid may not affect the area inside the burn itself, it likely could affect the marginal zone around the lesion and would reduce inflammation around a burn which certainly could affect a nearby nerve for the better/worse.

Do you care to share your RF technique? I would bet it does not involve U/S

 

[caedmon]

I was told by an attending once (and it may or may not be total BS- I never looked it up), that steroid post burn reduced the risk of neuritis and neuroma formation.