Ilioinguinal Neuralgia

Article Author:
Khaled Elsakka
Article Author (Archived):
Hajira Basit
Article Editor:
Abdallah Allam
Updated:
7/30/2019 3:34:46 PM
PubMed Link:
Ilioinguinal Neuralgia

Introduction

Ilioinguinal neuralgia is a frequent cause of pain in the lower abdomen and the upper thigh. The ilioinguinal nerve is a mixed nerve that originates from the anterior rami of T12 and L1 nerve roots. It emerges near the lateral border of the psoas major muscle and goes inferior through the anterior abdominal wall, being sub-peritoneal and anterior to the quadratus lumborum muscle until it reaches the iliac crest. Then the ilioinguinal nerve goes through the transverse abdominis and the internal oblique muscles. It becomes superficial by passing through the superficial inguinal ring anterior to the spermatic cord. It gives motor innervation to the transverse abdominis and the internal oblique muscles. Also, it carries sensory information from the anterior surface of the scrotum and root of the penis in males or labia majora and mons pubis in females, and a small area of the upper anteromedial thigh. Because of its long course, entrapment or injury of the nerve after lower abdomen surgeries is common. Male or female patients can complain of pain, paresthesia and abnormal sensation in the area supplied by the nerve.

Diagnosis of the ilioinguinal neuralgia requires a careful history, physical examination, electrophysiologic studies, and ultrasound examination. Treatment of the ilioinguinal neuralgia includes conservative measures as oral analgesics, anticonvulsants, rehabilitation as electro-analgesic currents, and myofascial release. If conservative measures do not control symptoms, ultrasound-guided block, hydro-dissection, or radio-frequency ablation of the nerve can provide satisfactory relief of symptoms. Resistant cases may require neurectomy.[1][2][3]

Etiology

A) Traumatic:

1- Iatrogenic (during surgery)[2][4][5][4][2]:

  • Inguinal hernia repair
  • Traumatic trochar from laparoscopic surgery
  • Appendectomy and hysterectomy
  • Abdominoplasty
  • Orchiectomy

2- Accidental[6]:

  • Blunt abdominal trauma
  • Femoral catheterization
  • Lower external oblique aponeurosis disruption (hockey players) 

3- Stretch trauma:

  • Pregnancy

B) Idiopathic - nerve entrapment at:

  • The paravertebral area
  • Iliac crest
  • Rectus border muscle
  • Inguinal region

These nerve entrapments often result from abnormalities in the musculoaponeurotic connective tissue (tight fascial planes).[7] 

Epidemiology

Ilioinguinal neuralgia is a common cause of chronic lower abdominal and anterior pelvic pain. The ilioinguinal neuralgia is not uncommon following the surgical repair of an inguinal hernia, and it is rarely because of stretch or entrapment neuropathy.[8]

Pathophysiology

A) In cases of nerve trauma, partial or complete transection can occur, In the cases of a total cut of the nerve, Wallerian degeneration may follow. 

B) In cases of nerve entrapment:

  • At the site of the entrapment, there is compression and flattening of the nerve
  • Proximal to the site of the entrapment, there is swelling of the nerve

The net result is progressive ischemia of the nerve, potetially leading to the following[9]:

  • Pain
  • Loss of function
  • Impaired sensory input
  • Hair loss and trophic changes in the anterior surface of the scrotum and root of the penis in males or labia majora and mons pubis in females
  • A small area of the upper anteromedial thigh and weakness of the muscles supplied by the ilioinguinal nerve

History and Physical

Entrapment neuropathies are common disorders which lead to significant disability. Correct diagnosis is essential for proper management. History taking and physical examination are a cornerstone in the diagnosis of the ilioinguinal neuralgia. Patients of ilioinguinal neuralgia complain from pain (mostly postsurgical) in the lateral aspect of the iliac fossa, lower abdomen, and upper thigh, as well as abnormal sensation in the cutaneous distribution of the nerve (hyperesthesia or hypoesthesia). On examination, there is tenderness on palpation 1 inch medial and inferior to the anterior superior iliac spine and impaired sensation along the sensory distribution of the nerve. Complete neurologic examination is mandatory to exclude genitofemoral neuralgia, lumbosacral radiculopathy, and plexopathy.[10]

Evaluation

1-Ultrasound examination: tracing of the nerve starting from the psoas major border is difficult because of the small size of the nerve and the depth of the nerve, especially in obese patients. It is easy to trace the nerve at the iliac crest down to the superficial inguinal ring and see the cause of the entrapment (for example; scar of surgery). An ultrasound-guided block can confirm a diagnosis of the ilioinguinal neuralgia.[11]

2-Electrophysiologic studies: benefit of the electrophysiologic examination for diagnosis of the ilioinguinal nerve injury is questionable. Electrophysiologic studies are more directed to exclude lumbar radiculopathy and plexopathy.[3]

3-Magnetic resonance imaging: performed on the lumbosacral spine to exclude lumbar radiculopathies.

Treatment / Management

There are multiple strategies to treat chronic groin pain.[12][13] The pain of neuropraxia is typically temporary and disappears with time. Sometimes, the chronic groin pain persists and interferes with the activities of daily living.[5]

A) Conservative treatment[14][15][14]:

1 - Lifestyle modification:

  • Walking, stooping or hyperextension of the hip joint exacerbates chronic groin pain - the recumbent position and flexion of the hip joint and thigh relieves pain

2- Painkillers:

  • Includes non-steroidal anti-inflammatory drugs (NSAIDs), opioids, antiepileptics, and antidepressants

3- Rehabilitation:

  • Transcutaneous electric nerve stimulation, myofascial release, and acupuncture can control symptoms of the ilioinguinal neuralgia

B) Ultrasound-guided nerve block:[15]

Aim:  interruption of the neuronal transmission leading to temporary pain relief.

Substances injected:  local anesthetics (with or without steroids) or neurolytic agents.

Principal: injection of these chemicals prevent neuronal transmission through ilioinguinal nerve fibers either by blocking membrane ion channels or by denaturation of axon proteins.

Technique: 

1 - Patient position: supine

2 - Use a linear probe with frequency ranging from 5 to 10MHZ

3 - Place the probe transversely and start scanning from the anterior superior iliac spine

The nerve lies between transversus abdominis and internal oblique muscles lateral to the inferior epigastric artery and the iliohypogastric nerve. Operators introduce needle from lateral to medial using an in-plane approach to place the injectate accurately around the nerve.

C) Surgical treatment[16][5]:

Indications: persistent interactable pain after the failure of conservative measures.

Principal: Neurectomy involves identifying and dissecting the nerve, proximal to the area of trauma, or if possible, the entire length of the nerve.

The approach can be open or laparoscopic.

Differential Diagnosis

Differential diagnosis includes:

  • Lumbar radiculopathy
  • Lumbar plexopathy
  • Genitofemoral  neuralgia
  • Ilio-hypogastric neuralgia
  • Inguinal hernia
  • Hydrocele
  • Varicocele.

A thorough history, physical examination, electrophysiologic studies, ultrasound examination, magnetic resonance imaging, and individual nerve block can help differentiate the exact cause of the lower abdomen and groin pain.[17]

Prognosis

Chronicity of the pain after injury or entrapment of the ilioinguinal nerve is not uncommon. But, the majority of patients respond well to nerve block or surgical neurectomy. 

Complications

1- Complications of the non-steroidal anti-inflammatory drugs[18][19][20]:

  • Gastritis
  • Peptic ulcer
  • Nephropathy
  • Hepatotoxicity
  • Hypertension
  • Bleeding/thrombosis

2- Complications of the central painkillers as gabapentin[21]:

  • Ataxia
  • Dizziness
  • Fatigue
  • Somnolence
  • Fever
  • Nystagmus
  • Peripheral edema

 3- Complications of the nerve block[22][23][24][25]:

  • Peripheral nerve injury or vascular injury.
  • Transient femoral anesthesia 
  • Bowel perforations
  • Pelvic hematomas

Ultrasound guidance lowers the incidence of above-mentioned complications.

  • Ilioinguinal blocks require a small volume of injection; the possibility of local anesthetic toxicity is less frequent.

 4- Complications of the neurectomy[5]:

  • Infection
  • Hematoma
  • Seroma
  • Testicular Edema
  • Tingling

Deterrence and Patient Education

  • Reduction of body weight
  • Avoid positions and activities that precipitate pain

Enhancing Healthcare Team Outcomes

Prevention of the ilioinguinal neuralgia is possible; surgeons should work to avoid injury of the nerves near the field of the surgery and use meshes which don't induce fibrotic reactions. Nurses and therapists should teach patients a healthy lifestyle to minimize pain and improve the activities of daily living. The diagnosis and treatment of ilioinguinal neuralgia need an interprofessional approach. Collaboration between physiatrists, neurologists, pain physicians, and surgeons should direct a proper approach to therapy to improve prognosis. 



  • (Move Mouse on Image to Enlarge)
    • Image 2100 Not availableImage 2100 Not available
      Contributed by Gray's Anatomy Plates

References

[1] Starling JR,Harms BA, Diagnosis and treatment of genitofemoral and ilioinguinal neuralgia. World journal of surgery. 1989 Sep-Oct;     [PubMed PMID: 2815802]
[2] Ndiaye A,Diop M,Ndoye JM,Konaté I,Ndiaye AI,Mané L,Nazarian S,Dia A, Anatomical basis of neuropathies and damage to the ilioinguinal nerve during repairs of groin hernias. (about 100 dissections). Surgical and radiologic anatomy : SRA. 2007 Dec;     [PubMed PMID: 17985072]
[3] Cho HM,Park DS,Kim DH,Nam HS, Diagnosis of Ilioinguinal Nerve Injury Based on Electromyography and Ultrasonography: A Case Report. Annals of rehabilitation medicine. 2017 Aug;     [PubMed PMID: 28971057]
[4] Whiteside JL,Barber MD,Walters MD,Falcone T, Anatomy of ilioinguinal and iliohypogastric nerves in relation to trocar placement and low transverse incisions. American journal of obstetrics and gynecology. 2003 Dec;     [PubMed PMID: 14710069]
[5] Kim DH,Murovic JA,Tiel RL,Kline DG, Surgical management of 33 ilioinguinal and iliohypogastric neuralgias at Louisiana State University Health Sciences Center. Neurosurgery. 2005 May;     [PubMed PMID: 15854249]
[6] Starling JR,Harms BA,Schroeder ME,Eichman PL, Diagnosis and treatment of genitofemoral and ilioinguinal entrapment neuralgia. Surgery. 1987 Oct;     [PubMed PMID: 3660235]
[7] Toussaint CP,Perry EC 3rd,Pisansky MT,Anderson DE, What's new in the diagnosis and treatment of peripheral nerve entrapment neuropathies. Neurologic clinics. 2010 Nov;     [PubMed PMID: 20816274]
[8] Hahn L, Treatment of ilioinguinal nerve entrapment - a randomized controlled trial. Acta obstetricia et gynecologica Scandinavica. 2011 Sep;     [PubMed PMID: 21615360]
[9] Mackinnon SE, Pathophysiology of nerve compression. Hand clinics. 2002 May;     [PubMed PMID: 12371026]
[10] ter Meulen BC,Peters EW,Wijsmuller A,Kropman RF,Mosch A,Tavy DL, Acute scrotal pain from idiopathic ilioinguinal neuropathy: diagnosis and treatment with EMG-guided nerve block. Clinical neurology and neurosurgery. 2007 Jul;     [PubMed PMID: 17481807]
[11] Gofeld M,Christakis M, Sonographically guided ilioinguinal nerve block. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2006 Dec;     [PubMed PMID: 17121952]
[12] Bay-Nielsen M,Perkins FM,Kehlet H, Pain and functional impairment 1 year after inguinal herniorrhaphy: a nationwide questionnaire study. Annals of surgery. 2001 Jan;     [PubMed PMID: 11141218]
[13] Lichtenstein IL,Shulman AG,Amid PK,Montllor MM, Cause and prevention of postherniorrhaphy neuralgia: a proposed protocol for treatment. American journal of surgery. 1988 Jun;     [PubMed PMID: 3377120]
[14] Amid PK,Hiatt JR, New understanding of the causes and surgical treatment of postherniorrhaphy inguinodynia and orchalgia. Journal of the American College of Surgeons. 2007 Aug;     [PubMed PMID: 17660088]
[15] Eichenberger U,Greher M,Kirchmair L,Curatolo M,Moriggl B, Ultrasound-guided blocks of the ilioinguinal and iliohypogastric nerve: accuracy of a selective new technique confirmed by anatomical dissection. British journal of anaesthesia. 2006 Aug;     [PubMed PMID: 16698865]
[16] Rosen MJ,Novitsky YW,Cobb WS,Kercher KW,Heniford BT, Combined open and laparoscopic approach to chronic pain following open inguinal hernia repair. Hernia : the journal of hernias and abdominal wall surgery. 2006 Mar;     [PubMed PMID: 16501867]
[17] Knockaert DC,D'Heygere FG,Bobbaers HJ, Ilioinguinal nerve entrapment: a little-known cause of iliac fossa pain. Postgraduate medical journal. 1989 Sep;     [PubMed PMID: 2608591]
[18] Antman EM, Evaluating the Cardiovascular Safety of Nonsteroidal Anti-Inflammatory Drugs. Circulation. 2017 May 23;     [PubMed PMID: 28533319]
[19] Shin S, Safety of celecoxib versus traditional nonsteroidal anti-inflammatory drugs in older patients with arthritis. Journal of pain research. 2018;     [PubMed PMID: 30588073]
[20] García-Rayado G,Navarro M,Lanas A, NSAID induced gastrointestinal damage and designing GI-sparing NSAIDs. Expert review of clinical pharmacology. 2018 Oct;     [PubMed PMID: 30139288]
[21] Yasaei R,Saadabadi A, Gabapentin (Neurontin) 2018 Jan;     [PubMed PMID: 29630280]
[22] Jeng CL,Torrillo TM,Rosenblatt MA, Complications of peripheral nerve blocks. British journal of anaesthesia. 2010 Dec;     [PubMed PMID: 21148659]
[23] Rosario DJ,Jacob S,Luntley J,Skinner PP,Raftery AT, Mechanism of femoral nerve palsy complicating percutaneous ilioinguinal field block. British journal of anaesthesia. 1997 Mar;     [PubMed PMID: 9135313]
[24] Jöhr M,Sossai R, Colonic puncture during ilioinguinal nerve block in a child. Anesthesia and analgesia. 1999 May;     [PubMed PMID: 10320167]
[25] Vaisman J, Pelvic hematoma after an ilioinguinal nerve block for orchialgia. Anesthesia and analgesia. 2001 Apr;     [PubMed PMID: 11273948]