A non-scalpel technique for carpal tunnel release: percutaneously looped thread transection of transvers carpal ligament

Thankyou for that posting. That is certainly a technically clever approach to dividing the transverse carpal ligament and seems more promising than the other recently described technique of multiple needle fenestration. Of course, where possible, I would generally prefer not to sacrifice the mechanical functions of the TCL at all but there is often no alternative if median nerve function is to be preserved. I would make two, somewhat inter-related, comments on your pilot study.

Firstly the technique is very reliant on the quality of ultrasound imaging and therefore requires a significant investment in a good quality ultrasound scanner and the expertise to use it - including of course requiring two people (I'm pretty sure I could not operate the scanner and manipulate needle and syringe with only 2 hands myself). You have included some lovely images in that paper but as is often the case with ultrasound stills the figure illustrating the thread in place would be unconvincing without the marking of the thread position - I presume that, in real life, you can move the thread itself  and the tendons to help distinguish it.

Secondly, some of the structures which are sometimes accidentally divided during conventional or endoscopic surgery, such as the palmar cutaneous and recurrent motor branches of the median nerve are not easliy identified on ultrasound (at least at present) and are presumably just as much at risk from your thread as from a scalpel, especially when their anatomical course is unusual.

Overall then I think that is a promising technique which deserves more exploration and certainly seems to have theoretical advantages over current methods of endoscopic decompression. I will draw your paper to the attention of my local hand surgeons. JB

Dear Dr Bland:

Per Dr. Joseph Guo request, I would like to discuss with you about your concerns and questions for the new technique. First of all, thank you for your comments on the technique of TCTR.

I have been using ultrasound for musculoskeletal diagnosis and guided injections on daily basis for a few years. I am the pioneer certificated physician of musculoskeletal ultrasound diagnosis of AIUM in USA. Follows are the answers to the questions and concerns you raised with my experience.

1. Musculoskeletal ultrasound has been very popular in the medical field. The price is reasonable from $25,000 to 40,000. It can also be used in the diagnosis and ultrasound guided procedures for other positions of the body.

2. The procedure of TCTR is similar to an carpal tunnel injection procedure. one hand handles the needle and the other hand guides the needle to process. We have done a number of ultrasound guided intracarpal tunnel median nerve hydro-dissection cases with no difficulty. So I think one hand control needle, the other hand manipulate the probe is not difficult at all. You do not need to have an assistant, certainly it is best if you have an assistant.

3. You may see the thread through the ultrasound without moving thread, definitely, moving thread helps to confirm the thread position for the physician who just starts to use ultrasound.

4. Not like OCTR or ECTR ( they only can see one side of TCL ), ultrasound can see both sides of TCL and median nerve and its recurrent motor branch,and SPA, ulnar nerve and its branches. You have experience, you also can see sensory branch of median nerve. The other unique feature of the technique is that the process is reversible before thread transecting. After looping the thread about the TCL, you may check the loop with ultrasound to confirm that there is no non-targeted in the loop, therefore, avoid iatrogenic injury.

5. Ultrasound can rule out secondary CTS, that can help you to decide the choice: OCTR or TCTR.

Thank you very much for your interest in the technique. Should you have any further question, please feel free to contact me.

Danqing Guo, MD
BayCare Clinic
Green Bay , Wisconsin, USA

As you will gather from the ultrasound section of this site I do a fair bit of this myself and I think it is developing into a very useful additional investigation in nerve disease. Scanners continue to improve but at the moment, using a portable scanner costing UKP 20-30,000 I do not think it is possible for the average user to reliably identify the recurrent motor branch of the median nerve, nor the palmar cutaneous branch much beyond the point at which it branches off the main median nerve trunk. Given a 22MHz transducer and a 70k scanner with an expert user you can do better but most surgeons here would feel that even a 20k additional capital outlay to add their operating setup would be a significant expenditure and would be wary of having to learn the technique of ultrasound so I think my reservations stand for the moment but it is certainly an ingenious technique which deserves further exploration. I think you could only really make a fair assessment of safety and efficacy with a large multicentre study - probably at least 1000 cases given that you are comparing with procedures that already have quite low complication rates. 

As regards the use of an assistant I suspect we agree really - it is technically possible to hold the tranducer in one hand and the needle in the other but that leaves you operating the machine controls with your feet, and if injecting then I would generally prefer to have two hands free to manipulate the syringe - again one handed can be done but I would just feel less comfortable with a much more complex manual task - we physicians are perhaps not as good with our hands as surgeons! 

I note that you also do injections under ultrasound control and I think this is also an interesting area that deserves more formal investigation. The existing literature tends to suggest that, in practice, the outcome of steroid injection is essentially similar regardless of exactly where the steroid is placed - see especially the trial by Dammers who deliberately injected a few centimetres proximally. As yet there is not a definitive trial demonstrating superiority of ultrasound guided over blind injections, nor one conclusively proving that you need to place the injection in the tunnel so I would love to see some well designed studies tackling that issue too. JB

Hi, JB:
For your reference there are two recently published articles about the thread carpal tunnel release (TCTR):

Guo, Danqing; Guo, Danzhu; Guo, Joseph; Steven, Schmidt; Rachel, Lytie (2016-09-12). "A Clinical Study of the Modified Thread Carpal Tunnel Release (TCTR)". HAND (2016). doi:10.1177/1558944716668831

Guo, Danqing; Guo, Danzhu; Guo, Joseph; Daniel, Malone; Nathan, Wei; Logan, McCool (20 August 2016). "A cadaveric study for the improvement of thread carpal tunnel release". Journal of Hand Surgery (2016). doi:10.1016/j.jhsa.2016.07.098. PMID 27554942

The cadaveric study of thread trigger finger release has been completed and the clinical study is in process. Some articles about the topic will be published soon.

Thanks,

Joseph

Thankyou. I've already seen the cadaveric study but I hadn't noticed the paper in HAND yet. It's getting to be quite a decent series of operations but I'm less impressed by the idea that it is superior to conventional surgery because your comparison is simply with a single study performed by other authors (Trumble 2002 - quite an old paper now). If one chose a different comparator then the answer would be different - for example - your change in SSS at 12 weeks is from 3.19 to 1.39 or -1.8, ours after OCTD is -1.71 - which is unlikely to be significantly different - especially as our patient populations are probably different at baseline. I would not therefore accept that TCTR definitely represents a 'better' approach. We did of course hear much the same about ECTR and in the end it turns out to be just about as effective as OCTR. Hopefully other units will take an interest in the technique and some randomised prospective studies will be carried out as it is obviously a very elegant way of achieving division of the TCL when that is required. JB