Ilioinguinal nerve division does not reduce pain after hernia surgery

Chronic groin pain can be a troubling and on occasion disabling symptom that affects between 5-10% of patients who undergo an inguinal hernia repair. The aetiology is unclear although a number of patient and operative factors have been identified.

  • Those with other chronic pain conditions (e.g. chronic neck pain & chronic back pain) appeared to be predisposed to developing post-operative pain after hernia surgery
  • Patients who have a lot of pain prior to their surgery are at increased risk of having persistent pain following the procedure (i.e. although one can fix the hernia, it does not always fix the pain)
  • Patients who have a lot of perioperative pain are at increased risk for developing pain in the long term following surgery.
  • Although it was hoped that lightweight and partly real absorbable mesh might reduce the incidence of long-term pain, the data does not suggest that there is an overwhelming beneficial effect to these measures. Clearly advances inmates technology are not the only answer to chronic groin pain after inguinal hernia surgery.

happy patient after inguinal hernia surgery

Over the years a number of surgeons have looked at the importance of nerve entrapment as a cause for chronic groin pain following inguinal hernia surgery. In particular, there has been much speculation that entrapment of the ilioinguinal nerve may be a causative factor. A number of investigators have explored the role of elective division of the ilioinguinal nerve in an attempt to reduce the incidence of chronic groin pain after inguinal hernia surgery. Others have re-operated on patients who have chronic groin pain with a view to division of the nerve as a secondary procedure. For the most part the results have been mixed and there have been a number of calls for randomised clinical trials to assess the utility of this type of intervention.

 

A recent meta-analysis published in the June 2018 edition of the Hernia journal assessed the results of nine separate randomised controlled clinical trials comparing preservation versus planned elective division of the ilioinguinal nerve during inguinal hernia surgery.

 

The authors noted that almost 10% of patients who had preservation of the ilioinguinal nerve experienced chronic groin pain at six months after surgery. This had fallen to 4.8% at one year after surgery. Initial outcomes in the group who underwent elective division of the nerve were better with this group showing a significant reduction in groin pain at six months after surgery (relative risk (RR) 0.47, p = 0.02). Moderate and severe pain was also substantially reduced 6 months after surgery (RR 0.57, p = 0.01). However, the reduction in chronic groin pain at six months must be balanced against a significant increase in subjective groin numbness at the same time (RR 1.55, p = 0.06).

 

At 12 months after surgery, the 22 groups had merged and there were no significant differences in rates of overall groin pain in the ilioinguinal nerve preservation group versus the nerve division group (RR 0.69, p = 0.38). In addition, there was no difference between the two groups in terms of numbers complaining of moderate to severe groin pain (RR 0.99, p = 0.98). Rather surprisingly, the prevalence of groin numbness was also similar between the two groups after 12 months of surgery (RR 0.79, p =0.48) i.e. Numbness was not a major or persisting issue even for those patients who had elective division of the ilioinguinal nerve.

 

The authors concluded that although elective division of the ilioinguinal nerve may reduce the severity and frequency of chronic groin pain at six months after surgery, it has a negative impact on the sensation of numbness and the beneficial effect in terms of reducing chronic pain is not maintained out to 12 months after surgery where nerve preservation and nerve division groups showed a similar incidence of groin pain and numbness. One cannot therefore recommend elective division of the ilioinguinal nerve during elective primary groin surgery.

 

Reference

Charalambous MP, Charalambous CP (2018). Incidence of chronic groin pain following open mesh inguinal hernia repair, and effect of elective division of the ilioinguinal nerve: meta-analysis of randomized controlled trials. Hernia 22, 401–409

Inguinal hernias: A brief overview

Diagnosis

Patients often diagnose that they have a hernia as the lump or swelling is usually obvious. Your GP will usually be able to confirm the diagnosis. The lump may be more obvious when standing and coughing.

If the diagnosis isn’t obvious, investigations such as an abdominal ultrasound, CT scan or MRI may be helpful to confirm the diagnosis.

Treatment

Small hernias that are not causing any symptoms do not always require treatment. In part the decision to treat or not will depend on your symptoms from the hernia, where it is located and other factors such as your general health. A watchful waiting approach may be best for some people.

Enlarging or painful hernias usually require surgery to relieve discomfort and prevent serious complications.

There are two general types of hernia operations — open hernia repair and laparoscopic repair.

Open hernia repair

Open hernia repair (also called a tension-free mesh repair) is perhaps the most commonly performed hernia operation and can usually be done with local anesthesia and sedation or general anesthesia. An incision in made in your groin and the surgeon pushes the protruding tissue back into your abdomen. The surgeon then sews the weakened area, often reinforcing it with a synthetic mesh. The opening is then closed with stitches, staples or surgical glue.

After the surgery, you’ll be encouraged to move about as soon as possible, but it might be several weeks before you’re able to resume normal activities.

Laparoscopy

In this minimally invasive procedure, which requires general anesthesia, the surgeon operates through several small incisions in your abdomen. Gas is used to inflate your abdomen to make the internal organs easier to see.

A small tube equipped with a tiny camera (laparoscope) is inserted into one incision. Guided by the camera, the surgeon inserts tiny instruments through other incisions to repair the hernia using synthetic mesh.

Many patients who have had a keyhole or laparoscopic repair have less discomfort and scarring after surgery and perhaps, a quicker return to normal activities. However, some studies indicate that the risk of the hernia coming back is a little more likely with laparoscopic repair compared to an open tension-free repair.

Laparoscopy allows the surgeon to avoid scar tissue from an earlier hernia repair, so we usually recommend this approach for people whose hernias recur after traditional hernia surgery. It also might be a good choice for people with hernias on both sides of the body (bilateral).

Some studies indicate that a laparoscopic repair can increase the risk of complications and of recurrence. Having the procedure performed by a surgeon with extensive experience in laparoscopic hernia repairs can reduce the risks.

Open vs. Laparoscopic repair of inguinal hernias: Lap. repair may be better.

A recent study published in the March issue of Archives of Surgery 2012 suggests that patients who undergo a laparoscopic inguinal hernia repair (Total extraperitoneal inguinal hernia repair (TEP)), report higher patient satisfaction, less chronic pain and less impairment of inguinal (groin) sensation compared to those who undergo a tension-free open Lichtenstein repair.
Hernia Surgery. Two surgeons performing an operation