Post Hernia Surgery Helped by TENS and Should Surgeons be Doing Hernia Repairs if They do Not Know How to Deal with the Persistent Pain Afterwards?

Pain after hernia surgery is common. Transcutaneous nerve stimulation (TNS) seems to help post operatively and one wonders if it might have lasting effects. I was always taught that one should not do a procedure unless one can deal with the common complications. If a procedure has a “common” risk of pneumothorax, then one better be able to deal with it. It then follows that surgeons should not be doing hernia repairs because they do not know anything about dealing with the pain afterwards.

Pain Common Post Herniorrhaphy

Studies of post Inguinal Herniorrhaphy pains vary widely because drop out rates can be over 1/2 of patients (they might include mad ones who don’t want to deal with surgeon as well). One study with 80.8% retention found the following one year later:
“Pain in the groin area was reported by 28.7%, and 11.0% reported that pain was interfering with work or leisure activity.”

article here

Postherniotomy pain is a neuropathy

Study in press analysis of postherniotomy pain found good evidence for it being a neuropathy:

Pain in press 2008

Neurophysiological characterization of postherniotomy pain
Eske Kvanner Aasvang, Birgitte Brandsborg, Bente Christensen,Troels Staehelin Jensen, Henrik Kehlet

Better Surgical Management may help Central Mechanisms of Persistent Pain
I have recently seen two cases of bilateral hernia repairs. Both developed moderately severe pain and were treated quite cursorily by their surgeons. One was done many years ago and the patient has been suffering all this time. The other was done recently where pre-emptive analgesia should have been done. During anesthetic induced sleep, the spinal cord and brain is still barraged with pain messages which induce permanent changes heightening sensitivity to pain in that segment. One can prevent this by certain maneuvers – simply injecting local into the tissues to prevent barrage, or by administering ketamine before and after surgery which blocks NMDA pain pathways some. Work has been done on this “syndrome” by Dr. Joel Katz at York University in Toronto; he has been particularly interested in phantom limb syndrome. Perhaps post-op TNS can do this:

J Pain. 2008 Apr 1 [Epub ahead of print] Hypoalgesic Effect of the Transcutaneous Electrical Nerve Stimulation Following Inguinal Herniorrhaphy: A Randomized, Controlled Trial. Santana JM, Filho VJ, Guerra DR, Sluka KA, Gurgel RQ, Silva WM Jr.

abstract here

“In the group treated with active TENS, pain intensity was significantly lower 2 hours (P = .028), 4 hours (P = .022), 8 hours (P = .006), and 24 hours (P = .001) after the surgery when compared with the group that received placebo TENS.”Other Pain Mechanism

Other mechanism for persistent pains include local nerve entrapments and damage.

The nerves (genitofemeral and ilioinguinal) can be entraped in the hernia mesh and sometimes the mesh can form contracted plugs called Meshomas.

Scar Pains

Scar itself can generate persistent pain and there is a whole school of thought about how scar pain can cause widespread hypersensitivity (in Neural Therapy). Pure scar pain is an intradermal problem as most skin nerve are very close to the surface. Injection there requires the needle to be injected near parallel to the skin and blebbed up white as injection is moved up the scar. It helps to pre-bend the needle so it is easier to get parallel.

Nerve entrapment and Neuromas

Cut or entrapped nerves have point tenderness and perhaps refer pain or tingling. An aberrant nerve can form a bundle called a neuroma which is very tender. Steroid (Kenalog/triamcinolone) Injection is sort of neurolytic and can help dissolve neuromas. Steroids can also dissolve fat which would help free up the nerve as well. I inject Kenolog 40 mg. into these areas. More definitive approaches include cryotherapy (only temporary) or alcohol injection(permanent) into the offending nerves. One recent article used an implanted electrical nerve stimulator.
Myofascial & nerve tender areas

After scar work, one is often left with sensitive spots and surrounding soreness. I have been trying 5% lidocaine shots repeatedly to these areas; this strength is sort of neurolytic (nerve damaging) and can knock out the nerve for 3 wks – 6 month. I give them repeatedly (patients actually X the spots they want hit).

Posterior Segmental treatment

You, however, will not get the results you are looking with just that approach. I remember one clear cut case of purely post surgical unilateral inguinal neuropathic pain. I coud skin roll tender tissues all the way around to the back to the segments that feed the damaged nerve. There was muscle spasm paraspinously at that level as well and the segments were stiff. Subject had never had any back problems. When one thinks about it, it does not take much of a stretch to realize that if the anterior nerve is damaged, its companion dorsal nerve that feed the paraspinous muscles and tissues would also be effected. The reverse happens too. I recently saw one lady with anterior T7 rib pain. When the T7 paraspinous levels were needled free, the anterior rib no longer hurt (other reasons why that could have worked though).

This posterior paraspinous – anterior segment connection was noticed in the 1970′s and before by Dr. Chen Gunn from Vancouver. His successful research on WCB cases demonstrated that needling back and peripheral sites was imperative to successful treating back radiculopathy and arms pains (resistent tennis elbow included). I was so impressed by his work, I have spent time at his office twice in the last 25 years. Best needling spots were the rotatores over the facet joints. Some of them were very scerotic and hard. When needled and working out, caused significant benefit.

In the cases of inguinal nerve damage, it is easy to realize the nerve damage. Through keen observation, Dr. Gunn was able to demonstrate clearcut evidence of nerve damage in cases of paraspinous – peripheral pain. Paraspinously, there could be edema, now known as neurogenic inflammation from neuropathy – you can spot it by pressing a match head into segments. Still not impressed? Many times I have seen peripheral problems and checked around the back to see what it looked like. If you will look, in some cases you will find there is no hair at the involved segments – something Dr. Gunn taught but never ceases to amaze me. The hair will be in segments above and below and you know that has to be neurogenic. The facts the levels are spastic and tender helps too. The tender muscles in the arm or leg will often conform to certain spinal levels, another confirmatory sign. Dr. Gunn also reported that back pain subjects with tender muscles down the leg (again found to conform to certain spinal levels) will take almost as long to recover as frank radiculitis (sciatica).

Resetting Segmental Sensitivity

I have a recent case where I did the local injections with some results but didn’t get good results until I needled the tender segments in the back as well. Confirmation, I believe comes from an unlikely source -Pulsed Radiofrequency Lesioning of the Dorsal Root Ganglion. This is heating up the nerve center (ganglion) for peripheral nerve at its nerve central in the holes (foramen) leading out from the spinal vertebrae. The pulsed heat is often 60 degrees C which can disrupt the nerves some but not destroy them (there is no numbness or weakness resultant). This seems to “reset” the sensitivity of this nerve center. and give relief for months.

recent study:
Pain Physician. 2008 Mar;11(2):137-44.
Response to pulsed and continuous radiofrequency lesioning of the dorsal root ganglion and segmental nerves in patients with chronic lumbar radicular pain.
Simopoulos TT, Kraemer J, Nagda JV, Aner M, Bajwa ZH. abstract here
article here

I suspect repeated electrical segmental stimulation can also cause this resetting of sensitivity and is much less invasive. Knocking out peripheral muscle triggers by directly needling, can make it potentially more lasting as well.
Surgeons Should Do Better
The vicitms are treated poorly by insurers if they are unable to work because the insurer’s “book” says the patient should be better by now. Any rational person would realize that the situation must be more complicated then just post surgical soreness but I am expecting too much from insurers. I would have expected more for the surgeons who try to tell the patient they are fine (or I don’t know what the matter is so I will tell the insurance company nothing of benefit to them).

I have not gone over all the available treatments (eg – if pubic joint tender then have to consider SI joints). I would be interested in other people’s successes.


I have had a request for treatment options.

  • It has been recently suggested that surgeons remove the ilioinguinal nerve during surgery and be done with it:
    Ilioinguinal nerve excision in open mesh repair of inguinal hernia—results of a randomized clinical trial: simple solution for a difficult problem?
    The American Journal of Surgery, Volume 195, Issue 6, June 2008, Pages 735-740
    Fatemeh Malekpour, Seyyed Hadi Mirhashemi, Esmaeil Hajinasrolah, Nourollah Salehi, Ali Khoshkar, Ali Asghar Kolahi – “Chronic postsurgical inguinodynia was seen in 6% of patients in the ilioinguinal nerve-excision and 21% of the patients in the ilioinguinal nerve-preservation group (P<0.033)”
    Several thoughts on that:

    • I’m not sure I would have a hernia repair knowing there was a 1/4 chance I would end up with chronic pain. [Their review of literature gave a 25% rate of chronic pain after - do surgeons tell people that???]
    • Removal of the nerve obviously helps a great deal but would the ones who got it following removal be more difficult to treat
  • Hernia recurrence needs to be ruled out:
    Chronic Pain after Inguinal Herniorrhaphy
    Journal of the American College of Surgeons, Volume 205, Issue 2, August 2007, Pages 333-341
    George S. Ferzli, Eric D. Edwards, George E. Khoury
    They suggest: “Hernia recurrence may be a source of chronic pain and should be ruled out early in the evaluation. CT may be helpful for establishing a diagnosis in cases of recurrence
    that is not evident on physical examination. Some authors have advocated ultrasonography in these patients. MRI has also been used to detect recurrence, delineate mesh position, and demonstrate nonherniarelated causes of pain. Herniography has likewise reemerged as a useful technique in some of these patients.”

I think the first would be for the surgeon to fix his problem – a neurectomy.

The American Journal of Surgery 189 (2005) 283–287
Inguinal neurectomy for inguinal nerve entrapment: an experience with 100 patients
James A. Madura, M.D.a,*, James A. Madura, II, M.D.a, Chad M. Copper, M.D.a, Robert M. Worth, M.D.b

  • Incidence in literature from 1- over 30%
  • “Fifty-nine percent had pain that radiated to the leg, thigh, genital areas, or flank, and an equal number complained of activity-related symptoms.”
  • Pain is elicited by twisting away from side sore (author has this cute pic)

  • Diagnosis was confirmed by nerve block – most often it was the ilioinguinal nerve effected.
  • Operation done was Neurectomy: “The operations were done under general (93%) or regional/ local (7%) anesthesia and consisted of identification of the nerves followed by proximal resection where they exited the internal oblique muscle near the anterior iliac spine or the internal ring in the case of the genital branch of the genitofemoral nerve. The proximal end of the nerves were crushed and ligated with fine braided polyester suture, followed by application of either absolute alcohol or 12% phenol solution to the nerve end to prevent neuroma formation.” They got :”Total pain relief was attained in 72% of patients, partial relief in 25%, and no relief in 3%.” The did a review of previous literature and came up with following:

  • Concern they had was that the genitofemeral and ilioinguinal nerves can interconnect in some people so you have to know what you are doing and get adequate relief from local injections before surgery so know where to operate. Apparently only 20% of nerves in area are anatomical

Please Note. I realize this is a serious problem and have written a series of article about this condition which is available here:
Post-hernia Pains

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