Hanging Drop for Cervical ILESI - why the hate?

[seamonkey]

Fellow here,

I have various attendings that either love or hate the hanging drop technique. In my limited experience (n=10) hanging drop works just as well as LOR to air or saline ( n = approx 20 of each).

I'm trying to decide which to use in practice, and they seem equivalent. I have seen each fail as well - false loss with air and saline, wet taps with LOR (but never hanging drop)

I like the immediate indication I get with hanging drop. It seems just as successful as LOR, but I have found some people grimace at the thought of it.

I'd like to hear what y'all think the pro's/cons are vs the LOR technique, specifically for prone interlaminar CESIs

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[Aether2000]

They are not equivalent. The hanging drop technique works by creating a negative pressure in the cervical epidural space by tenting the dura inward towards the cord. Thus the 3 times wet tap rate and potential for cord injury. Given the much better and safer published techniques available, any injury using the hanging drop technique would certainly make a person liable for increased malpractice risk should there be a disaster.

 

[EdPierce]

i have been doing all of them with hanging drop this year as well, most of the time it works out fine so i am considering doing it in my own practice, you can feel the lor, you can see the change in the fluid column, and you have the xray... however.... i do miss that comforting feeling of the plunger bouncing in the ligament as you are getting close and there is no change with the hanging drop ... i think arguments against LOR is that it is too bulky to have a LOR syringe on top of the needle and then do a LOR technique in the neck - but i have found this not to be true with a 5cc lor syringe and i have considered trying it with a 3cc to reduce bulk but my institution doesnt carry them and im sure they have a slightly different feel

 

[lobelsteve]

LOR/Hanging drop? Who cares?

As long as you are well versed in CLO fluoroscopy and have adequate imaging to guide your Tuohy needle into a paramedian position between C7-T1, I think either technique followed by live fluoroscopy is reasonable. Of course, you still need to go AP for another live fluoro shot to ensure no vascular uptake.

 

[Aether2000]

For me it is a matter of patient safety. I would rather have the needle tip 3mm away from the cord than 1/2 mm away from the cord. The difference is not insignificant: the patient coughs or moves with the needle further advanced (as is required with the hanging drop technique), and the cord can be contused or pithed with the needle closer to the cord.

 

[Jcm800]

For me it is a matter of patient safety. I would rather have the needle tip 3mm away from the cord than 1/2 mm away from the cord. The difference is not insignificant: the patient coughs or moves with the needle further advanced (as is required with the hanging drop technique), and the cord can be contused or pithed with the needle closer to the cord.

Hanging drop is bad news. Unless you did this for blind thoracic epidurals for post op pain, I don't recommend this for cervical. Even if you did it throughout your residency, I don't recommend it. Also, unless sitting, the. Pressure gradient is not as profound. Avoid

 

[101N]

Also, unless sitting, the. Pressure gradient is not as profound. Avoid

Is this true for the 'epidural space'? Articles.

 

[Aether2000]

Anesthesiology. 2010 Sep;113(3):666-71. doi: 10.1097/ALN.0b013e3181e898e8.
Cervical epidural pressure measurement: comparison in the prone and sitting positions.
Moon JY, Lee PB, Nahm FS, Kim YC, Choi JB.
Source
Department of Anesthesiology and Pain Medicine, East and West Neo Medical Center, Kyung Hee University Medical School, and Seoul National University Hospital, Seoul, Republic of Korea.
Abstract
BACKGROUND:
The hanging drop technique is used for identifying the cervical epidural space, using its negative pressure. However, it is doubtful whether the epidural space intrinsically exhibits a negative pressure. We designed this study to test the hypothesis that the cervical epidural pressure (CEP) is significantly higher in the prone position than in the sitting position. To evaluate this hypothesis, we measured and compared 30 CEP values in the prone and sitting positions.
METHODS:
We measured and compared 15 CEPs in the prone group and 15 in the sitting group using a closed pressure measurement system under fluoroscopic guidance.
RESULTS:
All CEPs in the prone group were consistently positive (median, 10 mmHg; range, 4.8-18.7; mean+/-SD, 10.5+/-4.4) in contrast to the sitting group (median, -0.3 mmHg; range, -2.4-7.9; mean+/-SD, 0.5+/-2.8). CEPs in the prone group were significantly higher than in the sitting group (P<0.001).
CONCLUSION:
CEP was found to be significantly higher in the prone position than in the sitting position. Furthermore, CEPs were not consistently negative even in the sitting position. These results suggest that the hanging drop technique is inappropriate for identifying the cervical epidural space in either the prone or sitting positions. Clinical Trials Ref: NCT01009385.

 

[101N]

Thanks.

Biggest problem I have had with the HD is it's sensitivity. Any tissue plane pressure change or paraspinal vessel leads to a false positive contrast mess. I was taught it sitting/blind.

 

[bedrock]

LOR/Hanging drop? Who cares?

As long as you are well versed in CLO fluoroscopy and have adequate imaging to guide your Tuohy needle into a paramedian position between C7-T1, I think either technique followed by live fluoroscopy is reasonable. Of course, you still need to go AP for another live fluoro shot to ensure no vascular uptake.

You shoot live on CLO/lateral?

 

[lobelsteve]

You shoot live on CLO/lateral?

Yup, get a quick pic of live to show posterior line of contrast and confirm no myelographic features, then go AP for live contrast spread to confirm no vascular uptake.

10-20 seconds of fluoro to get down there, 4-5 seconds of fluoro divided among CLO/AP to demonstrate safety. 17G Tuohy and plastic 10cc for saline LOR, Omni through cute little catheter (CLC = 0.2cc priming volume), and then squirt of 2cc NSS, 2cc Celestone 12mg.

 

[Ligament]

Just use CLO. Inject contrast dorsal to ligamentum, advance in small increments, inject contrast ventral to ligamentum. Yes, use live fluoro when injecting in CLO. MAKE SURE U UNDERSTAND MIDLINE CROSSING GEOMETRY!!!!

 

[ampaphb]

I use CLO only if I can't get adequate straight lateral imaging.

AP view confirms if epidural fat is present

I use a 20 guage Crawford, not a 17g Tuohey

I also enter in the cervical notch whenever possible, so midline, not paramedian.

Other than that, Steve and I do things the same way 🙂

 

[Ligament]

Use a 25ga touhy as well

 

[Mister Mxyzptlk]

I combine the two and I have for years. I inject some local as I'm inserting the needle so there is liquid in the hub. I use LOR but often the first indication of entry is that the liquid drains out of the hub. The change in LOR can often be very subtle. If you see the liquid drain from the hub it gives you an early warning that you're in even if the tactile feedback is equivocal.

Belt and suspenders.

 

[emd123]

I've never done hanging drop. In fellowship, I learned cervicals advancing on lateral. I learned CLO here, then read up on it and started doing it in fellowship. It makes cervicals so easy, I couldn't believe it. That's the technique I use to this day. I use a 22 gauge tuohy. I haven't had a wet tap yet with this technique. I never do cervicals with sedation. I always do them at c7/t1. Contrast. Celestone 2cc, saline 2cc. Unfortunately, my fluoro doesn't have DSA, but if it did, I'd use it.

Hanging drop? What for? Try CLO. You can see everything. Especially if you start out very slightly paramedian on AP, hit and walk off lamina, then advance after going contra lateral oblique, you see everything. How far oblique? I just keep obliqueing as far lateral as possible until the shoulder/scapula or calvicle shadows get in the way, then oblique back up until everything comes back into perfect view. There's a great link to an article on my "cervical procedures and risk" thread that shows how the geometry works as well, in fact better than a true lateral.

http://mobile.studentdoctor.net/showthread.php?t=879018

http://www.painphysicianjournal.com/2011/march/2011;14;195-210.pdf

 

[pastafan]

Yup, get a quick pic of live to show posterior line of contrast and confirm no myelographic features, then go AP for live contrast spread to confirm no vascular uptake.

10-20 seconds of fluoro to get down there, 4-5 seconds of fluoro divided among CLO/AP to demonstrate safety. 17G Tuohy and plastic 10cc for saline LOR, Omni through cute little catheter (CLC = 0.2cc priming volume), and then squirt of 2cc NSS, 2cc Celestone 12mg.

Steve, What is the brand/length/model number of the catheter you use?

 

[lobelsteve]

I use CLO only if I can't get adequate straight lateral imaging.

AP view confirms if epidural fat is present

I use a 20 guage Crawford, not a 17g Tuohey

I also enter in the cervical notch whenever possible, so midline, not paramedian.

Other than that, Steve and I do things the same way 🙂

Midline is a mistake. If raphe, dura can be pressed and even with interlaminar line.

 

[ampaphb]

Midline is a mistake. If raphe, dura can be pressed and even with interlaminar line.

I start injecting contrast, even if I havent felt a loss, as soon as I am even with the posterior aspect of the facet.

Nonetheless, I will let Dr. Aprill know you think the method he has been using for more than 30 years is unsafe 😀

 

[lobelsteve]

I start injecting contrast, even if I havent felt a loss, as soon as I am even with the posterior aspect of the facet.

Nonetheless, I will let Dr. Aprill know you think the method he has been using for more than 30 years is unsafe 😀

Only according to his former educational committee chair. And a lot of us who have read his work.

PARAMEDIAN!

 

[NEPain]

This is a typical discussion on these boards. Everyone has an opinion that it the "right way". Given the lack of midline lig flavum, but the fact that the dura is consistently present argues in favor of hanging drop-if you know how to use it.

CLO is a useful tool. LOR is not. Hanging drop depends upon a negative pressure created by pushing the dura away from the needle. It's a very reliable technique, especially given that LOR is a very unreliable one.

My approach is a careful one utilizing hanging drop along with CLO views, and LOR if I feel the lig flavum. I guess if you're fresh out of fellowship you've yet to gain a perspective on this. Experience and will teach you. I've never had a wet tap.

Am I great? No. I'm careful and I look for practice to make sense. I've always been astonished that the hanging drop is dissed by people who have probably never used it. The endpoint can be a simple one mm drop of a bubble in the needle hub. If you're looking for the drop to be sucked down then you're wasting your time. Also, need to clear the needle periodically to make sure there's not a tissue plug at the tip.

Great technique.

 

[PinchandBurn]

I currently use CLO view, prone position to do ILESI. I love it, I think it's very safe this way.

Having said that, in my fellowship we used to do sitting Hanging Drop with fluro. In the sitting position, the negative pressure, certainly accentuates the 'hanging drop'. I dont think I would do the hanging drop in the prone position, because the negative pressure that you are anticpiating may be neutral since the abdomen may increase the pressure in the epidrual space. The only problem with sitting hanging drop is getting a real good 'midline fluro image'. You can usually get a nice lateral.

I know a lot of the prestigious institutions that still do hanging drop sitting, with fluro. Nothing wrong with it. Just pick one and master it. Or master both!

It's not the technique, it's the person doing the procedure.

 

[ampaphb]

I know a lot of the prestigious institutions that still do hanging drop sitting, with fluro.

I know a lot of prestigious institutions with incompetent staff. You are only as good as the folks who trained you. I am lucky to count Drs. Lobel and Aprill as mentors.

 

[painstop]

With experience (having done it all ways described), I agree with Mxptyl that using both fluid in the needle with LOR (and using CLO, paramedian, and generally C7-T1) is the way to go. The change in resistance is so subtle sometimes that the fluid drop gives you information a millisecond before you would have noticed it otherwise. With lumbar ILESI I don't use saline because it generally is unnecessary since the epidural space is larger and I don't like using saline unless necessary because it clouds the picture if you suspect a wet tap (you can still figure it out, obviously, but why use it unless necessary). I'm not saying other ways are wrong, I simply feel this technique gives you the best window for safety.

 

[joshmir]

I do prone, advance some in AP, then go CLO

Then LOR as Im getting close ( but not there yet based on CLO)

If mushy, I switch to hanging drop

When Im where I need to be on flouro, if I haven't had a hanging drop change (sometimes very subtle, don't look for the drop to get "sucked in", sometimes it just quivers) I check with contrast

I reinsert stylet often and make sure the whole needle is filled with a fluid column

Never had a CESI wet tap; done over a hundred; so far a fan of hanging drop

If I ran the clinic, I would do them with 20g touhy (use 17g where I am now) all sitting hanging drop advancing with lateral flouro; I like the 2 handed control you get with hanging drop, and I like how in sitting position (theoretically) patients jerk forward away from the needle, whereas with prone they jerk backwards into your needle (never happened to me yet)

The key is CLO control so you don't advance too deep "waiting" for the LOR or hanging drop change

 

[Mister Mxyzptlk]

Never had a CESI wet tap; done over a hundred

 

[specepic]

doing an "early" contrast view in CLO which shows dye flow flow back over lamina is my favorite safety view for CESI

I use LOR but may try 'drop' again (did some in fellowship)

CLO is a game changer in the CS. The needle often looks deeper than it really is, partially b/c I advance fairly paramedian, partially b/c I don't oblique super far

better to have it look too deep than too shallow

 

[geauxg8rs]

better to have it look too deep than too shallow



That's what she said