Is this Swedish groin pain study from 2012 to 2015 the best pain study to date?

[Watchful]

Thanks – I certainly hope so. It’s progressing in the right direction.

[David M]

I guess they say in the survey to choose the worst level you experienced in the past week. Hopefully, by the end of a year you’ll be down to 1 or 1s and 2s at the most.

[Watchful]

David M,

It varies. I don’t have a constant level of pain or discomfort. I experience levels 1-4, but not 5-7. Most of the time I’m at 1-2, sometimes 3, and fairly rarely 4. This is now. Earlier on, it was worse. I was at 4 more often, and even reached 5 and 6 on occasion.

[David M]

Good point, GI.

Obviously, there is a tremendous amount of inertia in the industry. It doesn’t help when things also get mischaracterized.

[David M]

By the way, Watchful, would you be willing to grade your own pain according to the scale from the Swedish study?

“The question put to the patient was: grade the worst pain you have felt in the operated groin during the past week. The seven possible scores were: 1, no pain; 2, pain present, but easily ignored; 3, pain present, cannot be ignored, but does not interfere with everyday activities; 4, pain present, cannot be ignored, and interferes with concentration on everyday activities; 5, pain present, interferes with most activities; 6, pain present, necessitating bed rest; and 7, pain present, prompt medical advice sought.”

[Good intentions]

Here is something that might be the telling about how this whole hernia mesh mess has persisted – that 2002 paper has been cited 587 times.

https://scholar.google.com/scholar?cites=14122643666338993732&as_sdt=5,48&sciodt=0,48&hl=en
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It’s been cited in the Guidelines development articles –

https://link.springer.com/article/10.1007/s10029-009-0529-7

And, even worse, the people citing the paper in the 2009 EHS Guidelines article have exaggerated the Conclusion, or used the word “significantly” in a disingenuous way. The deeper you look the more you wonder. Kind of depressing when the experts seem to be trying to deceive people.
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This is from the paper linked above, the 2009 Guidelines paper. Ref 72 is the 2002 paper –

“… Most studies comparing mesh with non-mesh repair report less chronic pain with mesh repair [2, 72, 242]. The EU Hernia Trialists Collaboration review concluded that significantly less pain followed mesh repairs in randomised studies of open flat mesh versus non-mesh, TAPP versus non-mesh and TEP versus non-mesh [72].
…”

I assume that they extrapolated “significant” from the fact that statistical methods were used.

What the paper really said, below. “Appears” has been transformed to “significant”, seven years later.

“…
Conclusions
The use of synthetic mesh substantially reduces the risk of hernia recurrence irrespective of placement method. Mesh repair appears to reduce the chance of persisting pain rather than increase it.
…”

[Alephy]

Yes the meta analyses are affected by the quality of the included papers, it is a real problem…I almost understand why some surgeons rely on their own direct experience more than the guidelines 🤔

[Good intentions]

And Table 1A, the continuation.

https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=1422456_3TT1A.jpg

[Good intentions]

Click on the + sign for Table 1 to zoom in and study the listings. You might decide that the main benefit of this effort was to show how poor the existing data was. These meta-analyses take a whole pile of data, ranging from very poor to excellent, refereed, unrefereed, personal notes, etc., and try to combine the findings in to something rational. When they make their final conclusion, notice that there is no error range, just a simple statement of “findings”. When you actually look at the data that was used to draw the conclusion it’s kind of shocking. They make a firm statement from what looks like a pile of scraps.

Look at the categories. “Flat mesh vs other non-mesh”. “Laparoscopic vs open non-mesh”. Duration of follow-up: 6 days, 3 weeks, 1-13 weeks, 1 year. 31 of the 58 “trials” show “Not available” for pain data. Yet, they included a statement, of only two, about pain in the Conclusion.

Seriously, these mate-analyses are meant to try to find a direction from very unclear and sparse sets of data. Part of the Cochrane process requires from the authors; “Identification of relevant studies from a number of different sources (including unpublished sources); … The worse the quality of the data chosen the worse the conclusion will be.

That’s one reason that the registry studies are so much better. Even though they have flaws also, especially if the registry is not collecting the right types of data.

https://www.cochranelibrary.com/about/about-cochrane-reviews#:~:text=If%20the%20results%20of%20the,to%20generate%20an%20average%20result

Here is a link to the 2002 paper.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1422456/

And Table 1.

https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=1422456_3TT1.jpg

• This reply was modified 1 year, 3 months ago by  Good intentions.

[Watchful]

Mesh infection is rare as far as I know. The vast majority of problems with mesh are not from the mesh getting infected.

I think it’s very reasonable to look at any pain in the region regardless of severity or impact. No one wants to live with chronic pain even if minor, so that’s still a bad outcome, just not as bad as more serious pain. I don’t agree with ignoring pain that’s less severe than level 4 (pain present, cannot be ignored, and interferes with concentration on everyday activities) as some studies do.

[David M]

thought I would add this paragraph from the EU Trialist Collaboration of 2002, which gave the advantage to mesh over non mesh with regard to pain. They themselves seem to recognize the limitations of what they report, and which would seem to show why the Swedish study discussed here is better.

“Worldwide, there is a widely varying use of mesh techniques for groin hernia repair. One reason for not using mesh is concern about long-term morbidity. We found only two cases of mesh infection (one laparoscopically placed 56 and one placed by an open procedure 52). The 7,157 people repaired with mesh had very variable follow-up, however (Table 1). A second concern is the possibility of groin pain. 4 Our data indicate that it is more likely that mesh reduces rather than increases persisting pain. This finding should be interpreted cautiously. We adopted a broad definition and included any pain in the groin region (including testicular pain), regardless of severity or impact, reported around 1 year after the operation. As a consequence, prevalence rates differed widely between trials. ”

I mean, two cases of mesh infection out of 7000 sounds unbelievable.

The other major flaw which they recognize is that the pain that they speak of is not graded in any way, such as was done, seemingly well, in the Swedish study.

[David M]

Chronic pain defined as the following or worse occurring in the previous week….

4, pain present, cannot be ignored, and interferes with concentration on everyday activities;

• This reply was modified 1 year, 3 months ago by  David M.

[David M]

William,

From worst to best…for chance of chronic pain remaining after one year

These first three were from the same Swedish study..

Tapp 18.4%
Open anterior mesh…15.1%
Tep 14.9%

These next two are extrapolated guesses based on an earlier Danish/Swedish study that compared tissue based repairs to Lichtenstein…

Shouldice for indirect hernia ….10.6%
Marcy for indirect hernia…..9.64%

Finally, from Dr Kang’s recent telephone survey using the standards from the original Swedish survey

Kang (marcy type for indirect, I think)….1.7%

Some Caveats….

the Swedish study probably had other non-posterior types of open anterior mesh included besides Lichtenstein (I dunno, maybe plug and patch?…or others?). That might throw off the already shaky numbers in the second group.

The Kang numbers weren’t independently done. I mostly trust Dr Kang based on his posts and believe these numbers were told to us for education. Still, there could be cultural or other differences in the way Koreans would respond on the telephone vs the way the Swedes would respond in a written survey. There could also be minor differences in Korean anatomy that might make pain less of a problem in that area.

The original Swedish numbers had possibly significant differences in the expertise of the surgeon for the particular type of surgery. Over half of the open surgeries were done by surgeons doing less than 26 per year, while only around a quarter of the lap surgeons were than inexperienced. On the other hand, lap is harder to master, so these factors may have balanced out somewhat.

• This reply was modified 1 year, 3 months ago by  David M.

[William Bryant]

Thank you to the brainy contributors.
For a simpleton could someone just say which is least likely and most to result in chronic pain?

Like a league table format… It would be much appreciated.

I’m thinking Marcy, Shouldice, Lichtenstein?

By Marcy is that Dr Kangs variety of it?

[David M]

Of note: the Danish study referenced in the previous two posts gives results for indirect hernia. So, tissue repair for direct hernia still requires some comparison for pain vs Lichtenstein, Tep and Tapp.

[David M]

With the Danish study, which had an average followup time for the questionnaire of 31 months, the rankings for substantial discomfort were Shouldice 3.3%. Lichtenstein 4.7%. Marcy 3%.

While I’m sure it’s probably a little careless to try to extrapolate these numbers as a comparison to the Swedish study numbers, dividing the Lichtenstein Swedish number of 15.1% by the 4.7% of this study, and then multiplying that number by the 3.3% of the Shouldice, gives a hypothetical 4 pain rating for Shouldice of 10.6%. Doing a similar extrapolation for Marcy gives us a hypothetical 9.64% rating for it.

• This reply was modified 1 year, 3 months ago by  David M.

[David M]

Here’s a link to the Danish study that Dr. Towfigh alluded to earlier. This study was a breakdown of pain for surgeries done by open Mesh, Shouldice and Marcy. Unfortunately, this was earlier(2004) than the Swedish study and doesn’t define the levels of pain as well. The one takeaway seems to be that Shouldice and Marcy were slightly less pain causing than open Mesh in the overall cohort.

https://academic.oup.com/bjs/article/91/10/1372/6150885?login=false

[Good intentions]

Thanks David M. It is described by Dr. Kang himself, in post #35303 for anyone who wants to go directly to it.

I see that you have stuck with level #4 as the break point but in that thread Watchful had chosen #2. Defining any pain at all as chronic pain. Then followed up in several other posts reporting very high levels of pain for Dr. Kang’s repair method. No offense intended to Watchful but that is the way the words come out.

So, using #4 as the cutoff point, as the authors of the Swedish study did, in a one-to-one comparison, the Kang repair is at 1.7% and there are none at 5 or higher. The Swedish study is as as you show aboe, with any mesh repair being at 14.9% or higher for a level of #4. Kang – 1.7%, mesh – ~15%. Mesh also shows levels of significantly higher pain, level 5 or higher.

I am going to cross-post this thread in to that other thread so that people can see the one-to-one comparison.

[David M]

Dr Kang reported 4 or higher on 1.7% of his patients. His survey was by telephone and he didnt say how many he surveyed. He finished his post with this quote.

“These results have not been officially reported. So some might question the veracity of these results. However, I would like to say that my main interest is to find and improve problems rather than beautify the results of Kang repair.”

[David M]

As referenced from his post on o6/05/2023, Dr. Kang used the same survey questions.

https://herniatalk.com/forums/topic/summary-of-research-forum-experts-watchful-jf-nfg-gi-mike-m-bryant/

Summary of research-forum experts? Watchful-JF -NFG- GI- Mike M- Bryant