ILIOINGUINAL AND GENITOFEMORAL NEURALGIA AFTER
LAPAROSCOPIC VERSUS OPEN HERNIORRHAPHY
Dr Samer Narouze - Staff Anesthesiologist, The Cleveland Clinic Foundation
Introduction:
Injury to the nerves of the lumbar plexus is the most common complication of inguinal
herniorrhaphy with a reported incidence of 2-4%. Most of these nerve entrapment
syndromes are self-limited however, chronic severe neuralgia may develop and groin
pain after inguinal hernia repair can present a diagnostic challenge due to the marked
anatomic variability of the nerves in this region.
Case Report:
25 years old healthy male who underwent a laparoscopic inguinal hernia repair on the
right side about 4 years ago. After the laparoscopic herniorrhaphy he started to complain
of right groin and scrotal pain that was unresponsive to non-steroidal anti-inflammatory,
antidepressant and anticonvulsant medications. His pain was sharp, burning in the right
groin area, base of the scrotum and shoots down his right testis. He was diagnosed with
ilioinguinal neuralgia and he underwent multiple ilioinguinal nerve blocks with only
temporary pain relief for few hours. The patient then had unsuccessful right groin
exploration with ilioinguinal nerve resection. After 2 years of severe intractable groin and
genital pain hr consented for right orchiectomy which didn't help his pain and in fact he
continued to have phantom pain at the site of his right testis. Two years later the patient
underwent an unsuccessful exploratory scrotal surgery and then he was referred to our
institute for further management. At this point he was on oxycontin 120 mg/day and
neurontin 3600 mg/day and he was still rating his pain as 10/10.
His pain was mainly at the base of the scrotum and along his right spermatic cord and he
had complete relief after genitofemoral nerve block that lasted for a day. Unfortunately
his pain relief after genitofemoral nerve cryoablation was short-lived and the patient was
referred to chronic pain rehabilitation program for chemical dependency issue and
consideration for dorsal column stimulation.
In one study the incidence of nerve entrapment in laparoscopic heniorrhaphy was
reported to be as high as 4.2%, while in open herniorrhaphy it was only 1.8%. The
genitofemoral nerve was the most commonly affected nerve in laparoscopic
herniorrhaphy(2%), then comes the lateral femoral cutaneous nerve(1.1%) and the
ilioinguinal nerve(1.1%).
However in a review of more than 14,000 laparoscopic inguinal hernia repairs, the lateral
femoral cutaneous nerve was the most commonly affected nerve in 58% of total cases of
nerve injury, then the femoral branch of the genitofemoral nerve in 31% of cases.
Fixation of the mesh lateral to the internal inguinal ring can injury many nerves. The area
lateral to the internal ring is called the "triangle of pain" or the "electric zone". The
triangle of pain is bordered medially by the gonadal vessels and laterally by the iliopubic
tract and it contains from lateral to medial: the lateral femoral cutaneous nerve, the
genitofemoral nerve, the femoral nerve, and sometimes the atypical ilioinguinal nerve.
Groin pain after inguinal hernia repair can present a diagnostic challenge due to the
marked anatomic variability of the nerves in this region, and may warrant unnecessary
investigational or surgical procedures as in our case. In order to make a correct diagnosis
it is crucial to understand the anatomy of these nerves and the possibility of their
anatomic variability. In one study, the genitofemoral nerve was the dominant nerve with
no sensory contribution from the ilioinguinal nerve to the groin and genital area in 43%
of cases. However in 28% of cases, the ilioinguinal nerve was the dominant one with the
genitofemoral nerve shares a branch with the ilioinguinal nerve in the inguinal canal and
gives only motor branch to the cremaster muscle without any sensory branches to the
groin area.
Management of postoperative inguinal neuralgia usually starts with conservative
management in the form of rest and avoidance of activities that increase the pain, nonsteroidal anti-inflammatory, analgesics, antidepressants and anticonvulsant medications.
Diagnostic ilioinguinal or genitofemoral nerve block is very critical to identify which
nerve is involved and if there is a good response, cryoablation or chemical neurolysis
should be attempted. If mechanical nerve entrapment after laparoscopic herniorrhaphy is
suspected then exploration and removal of the offending staples is justified. Some
recommend surgical resection of the offending nerve as there is one series showed 90%
success after resection of the ilioinguinal nerve and 70% success after resection of the
genitofemoral nerve. However this is controversial as the patient may develop
deafferentation pain afterwards. It should be mentioned that if there is no obvious
etiology for the inguinal neuralgia (not postoperative) then L1-L2 radiculopathy should
be considered in the differential diagnosis.
PULSED RADIOFREQUENCY FOR THE TREATMENT OF ILIOINGUINAL NEURALGIA AFTER
INGUINAL HERNIORRHAPHY
DIMA ROZEN, M.D.1, AND JANE AHN, M.D.2
ABSTRACT
Background and Purpose: Ilioinguinal neuralgia secondary to inguinal hernia repair is
frequently a chronic, debilitating pain. It is most often due to destruction or entrapment of
nerve tissue from staples, sutures, or direct surgical trauma. Treatment modalities,
including oral analgesics, nerve blocks, mesh excision, and surgical neurectomy, have
varied success rates. Pulsed radiofrequency (PRF) has recently been described as a
successful method of treating chronic groin pain. Unlike conventional radiofrequency,
PRF is non-neurodestructive and therefore less painful and without the potential
complications of neuritis-like reactions and neuroma formation. Although the mechanism
is unknown, it appears that the interaction of an electromagnetic field and c-fos proteins
may alter normal transmission of painful impulses. Our study examines five patients
treated with PRF for ilioinguinal neuralgia secondary to inguinal herniorrhaphy.
Method: Five patients were diagnosed with chronic ilioinguinal neuralgia secondary to
inguinal hernia repair at our institution. Each patient was treated at vertebral T12, L1, and
L2 with root PRF at 42° C for 120 seconds per level.
Results: Four out of five patients reported pain relief lasting from four to nine months on
follow-up visits. Only one patient reported no pain relief whatsoever.
Conclusion: Ilioinguinal neuralgia is challenging to treat. We have demonstrated the
successful use of PRF for four out of five patients seen in our office.
My comment - So, you see that nerve injury after inguinal surgery is a known and
accepted complication that is difficult to treat and can be debilitating. I contend that
because vasectomy is done by gross visualization (as opposed to microsurgically, under
high magnification) and because there is individual marked anatomic variability of the
genitofemoral nerve and its branches, some patients develop post-vasectomy neuralgia.
The mechanism can be any of these: destruction or entrapment of nerve tissue from
staples, sutures, or direct surgical trauma to the nerve, or from inflammation and scarring
involving nerves. The herniologists acknowledge this complication while urologists on
average do not accept this as a vasectomy outcome.