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Inguinodynia - Myth or Truth
*Corresponding author

Dr Ramalingam
Professor, Department of General Surgery,
Kamineni Institute of Medical Sciences, Narketpally, Nalgonda District, Telangana state, India-508 254


1Professor, 2Asst. Professor, 3Post graduate, Department of General surgery, Kamineni Institute of Medical Sciences, Narketpally, Nalgonda, Telangana State, India.


Inguinodynia is a recognized complication after laparoscopy or open inguinal hernia surgery that may interfere with patients daily activities apart from livelihood, though recurrence rate is reduced significantly after usage of mesh and tension free repairs.

Keywords: Axonotmesis , funiculodynia, Inguinodynia, neuropraxia, neurotmesis, orchalgia.


Inguinodynia or chronic groin pain is one of the recognized complications of the commonly performed inguinal hernia surgery. Recurrence rate of inguinal hernia repair is reduced by use of mesh and tension free technique but, chronic post operative pain which is of concern to the hernia surgeon needs proper understanding the etiology, anatomy, diagnosis and treatment.

There is a perception among some surgeons in developing countries that there is no postoperative pain. This may not be true because of various reasons like no post-operative follow up, the perception that the pain is inevitable after surgery, non occurrence of pain in severe form and not knowing that there is an entity like inguinodynia.

Only when severe pain affects the quality of life, the patient consults the clinician.1 On the contrary in developed countries patients are more concerned with mild pain and may exaggerate because of availability of compensation. Pain is a subjective sensation which cannot be proved scientifically.

Incidence of inguinodynia may vary from surgeon to surgeon depending on the procedure, expertise, duration, knowledge of anatomy, prophylactic steps taken, apart from the psyche of the patient.2-4 As the treatment is not simple and cure not satisfactory, prevention may be a better option.


Chronic postoperative groin pain has been defined as pain lasting for more than 30 days and interfering with the patients activities in daily life or work activities [IASP-International Association for the Study of Pain].5

The type of pain in inguinodynia is broadly divided as Nociceptive, Neuropathic and Visceral. According to various studies, incidence of inguinodynia was reported to be 6 to 9 %, 0 to 53%,6 9 to 27.7% respectively. The incidence was found to be higher among those who have undergone open procedure (33%), as compared to laparoscopic procedure (20%). Inguinodynia due to mesh may be due to bulky mesh, idiosyncrasy, technical fault and allergy etc. To reduce this, mesh is not advocated for patients with hernia below 40 years without pain, those with recurrent hernia with mesh, and those with history of allergy. Also mesh is not advocated for those with history of Staphylococcus aureas infection and those subjects with Nytus type 1, 2 repair (getting surgery done by an expert in Shouldice repair). Surgeon must tailor the procedure to the individual patient and not patient to the procedure. A template or blanket technique for repair of every patient with a hernia is to be condemned.7


Somatic pain is due to damage to pubic tubercle and funiculodynia (spermatic cord - S 2,3,4).7,8 it may also be due to previous ligament/mesh injury, reaction of prosthetic material/mesh or new ligament, muscle injury caused by surgeon.

Neuropathic cause can be partial or complete transaction like neuropraxia, neurotomesis, axonotmesis, stretching, contusion, crushing, electrical damage, caught in the suture in open operation, tacks in laproscopic surgery, inflammation with granuloma (meshoma), fibrotic reaction and mesh encasement.9

Visceral pain may be due to venous congestion or encasement of cord.

During laproscopic repair ilioinguinal nerve is at risk as it is lateral to the internal ring, genitofemoral nerve is at risk as it is medial to the internal ring and iliohypogastric nerve may be damaged by tacks or staples along its entire length during mesh fixation.10-13 This can be avoided by using glue for mesh fixation.

Clinical Features

Patient may present with paraesthesia, burning sensation, hypoesthesia, neuralgic pain, pricking sensation, pain radiation to hemiscrotum (orchalgia), upper leg, upper back with trigger points and episodic nature aggravated by walking, tenderness in pubic tubercle and funiculodynia (ejaculative pain because of vas engulfment).14


Diagnosis of pain due to individual nerve damage like ilioinguinal nerve, iliohypogastric nerve, genitofemoral nerve is difficult because of overlapping of these 3 nerves with peripheral communication between their twigs and common roots of origin.15 Nerve blocks, neurectomies, CT and MRI, MR neurography (measuring water content of nerves), electromyography, did not give any concrete conclusion.16 Variety of causes may complicate the diagnosis of inguinodynia which include patients reporting pain for compensation,17 phantom limb pain (pain pathway is already established), removal of mesh plug and doing verniorrhaphy (for mesh plug eroding into iliac and femoral veins), pyramidalis syndrome, urological and gynaecological causes of pain.

Neuroanatomy of Nerves

  1. The ilioinguinal nerve is located over the spermatic cord covered and protected from the mesh by the investing fascia of internal oblique muscle.The protective fascia should not be damaged by removing the nerve from its natural bed. Dissecting the ilioinguinal nerve from the cord and placing it below the inguinal ligament, which was a teaching of the prior era, destroys the protective fascia of nerve and risks perineural scarring and direct contact of the nerve with the mesh.(Fig.1)
  2. Genital branch of genitofemoral nerve is located under the cord, covered and protected from direct contact with the mesh by the deep cremasteric fascia. Although small and difficult to see its location can be determined by the easily visible “blue line” of the external spermatic vein that is always adjacent to the nerve. To ensure the safety of the nerve, it must be kept with the cord while cord is separated from the inguinal floor under direct vision. Grasping the cord with the thumb and index finger and pulling it off the floor, is always a bad habit from the past and damages deep cremasteric fascia, which can lead to perineural scarring and direct contact with genital nerve with the implanted mesh (Fig.2).
  3. The iliohypogastric nerve is located between external and internal oblique layers covered and protected from the mesh by the investing fascia of the internal oblique muscle. The key step to expose the iliohypogastric nerve is opening the anastomatic cleavage between the internal and external oblique layers high enough to expose the internal oblique aponeurosis. This step that takes only a few seconds, easily and automatically exposes the iliohypogastric nerve. The iliohypogastric nerve is easily visible over the internal oblique aponeurosis. Lower down the nerve has hidden segment that runs inferiorly and laterally within the internal oblique muscle. This segment of the iliohypogastric nerve is the most vulnerable neural structure of the inguinal area because it is not visible within operative field. Passing through the internal oblique muscle or conjoint tendon for its fixation to the inguinal ligament, flat mesh or plug has the potential risk of injuring the intramuscular segment of the nerve with the needle or entrapping it by the suture (Fig.3).


Nonsurgical Treatment

It includes life style modification, use of analgesics, physical and psychological therapies and nerve blocks which have limited role in the management of inguinodynia.

Surgical Treatment

When conservative management fails or inguinodynia recurs, then surgical treatment is indicated. Triple neurectomy and ligation of the nerve endings implanting into muscle is the universally accepted gold standard procedure.18,19

Various studies showing neurectomy by open, laparoscopic or a combination of both open and laparoscopic approach:

According to Starling et al, out of 57 patients 32 patients underwent IIN neurectomy & 25 patients underwent GFN neurectomy. Neuralgia persists in 12.5%(4) patients who underwent IIN neurectomy & 28%(7) patients who underwent GFN neurectomy.

Heise et al had done individual neurectomies (IIN, IHN, GFN) in 20 patients. Out of which 40% (8) patients had persistent neuralgia & 2 patients developed complications, one for hematoma & another for testicular atrophy.5

Out of 30 patients with Inguinodynia Deysine et al (2002-USA) had done IIN neurectomy without excision of mesh in 22 patients. Remaining 8 patients were conservatively treated. Recurrent neuralgia persisted in 22 patients (100%) who underwent IIN neurectomies.21

Among 33 patients with Inguinodynia, Kim et al (2005-USA) had done IIN & IHN neurectomy in 16 patients. 10% patients had recurrent neuralgia & 90% have successful neurectomy.22

Amid et al (2004) has done triple neurectomies in 225 cases along with implantation of proximal nerve ending into internal oblique. Success rate was 100% with only 15% patients having transient neuralgia.12

The fact that the size of nanoparticles is same as that of proteins makes the nanomaterials suitable for bio-labeling. Apart from the size of the nanoparticles, in order to interact with the biological target, a biological or molecule coating or layer that acts as bio-inorganic interface should be attached to the nanoparticle in the form of biological coating with antibodies, biopolymers like collagen or monolayers of small molecules that make nanoparticles biocompatible. In addition, widely available optical detection techniques can be used to make the nanoparticles to fluoresce or change their optical properties.

Nanoparticle is the core of nanobiomaterial. It can be used as a convenient surface for molecular assembly and may be composed of inorganic or polymeric materials. It can also be in the form of nano-vesicle surrounded by a membrane or layer. The shape is more often spherical or cylindrical but plate-like or other shapes are also possible to make. The size and size-distribution is important in some cases, if penetration through a pore structure of cellular membrane is required. The size and size-distribution becomes extremely critical when quantum–sized effects are used to control material properties. A tight control of the average particle size and narrow distribution of sizes allow creating very efficient fluorescent probes that emit light at narrow wave length in a wide range of wave lengths. This helps in producing biomarkers with many and distinguished colors. The core itself must have several layers and be multi-functional like combining magnetic or luminescent layers so that one can detect both and manipulate the particles. The core particle is protected by several monolayers of inert material like silica. Organic particles those are adsorbed or chemisorbed on the surface of the particle are also used for this purpose. The same layer might also act as a biocompatible material. More often addition or deletion of layers of linker molecules is required to proceed with further functionalization. These linear linker molecules required for functionalization posses reactive groups at both the ends. One group attaches the linker to the nanoparticle and the other group can be used to bind various moieties like biocompatible antibodies, fluorescent dyes depending upon the function required with the application.

Tissue engineering is an upcoming field where nanobiotechnology has significant role to play. The natural bone surface quite often contains features that are about 10 nm across. If the surface of an artificial bone implant were left smooth the body would reject it because the smooth surface of the implant is likely to cause production of fibrous tissue covering the surface of the implant. This reduces the bone-implant contact which may result in loosening of the implant and further inflammation. If nano-sized features are created on the surface of the hip or knee implant, the chances of rejection can be minimized and also the production of osteoblasts can be stimulated. The effect can be demonstrated with polymeric, ceramic or even with metal materials. More than 90% of the human bone cells from suspension are adhered to metal surface and only 50% in the control samples. These findings are in favour of designing more durable and longer lasting hip or knee replacements and reduce the chances of implant getting loosened and thereby reduce the degree of inflammation.

In dentistry an artificial hybrid material prepared form 15-18 nm ceramic nanoparticles and poly co-polymer (methyl methacrylate) using tribiology approach, vesico-elastic behaviour of human tooth was demonstrated. An investigated hybrid material was deposited as a coating on the tooth surface, improved scratch resistance as well as possessed healing behaviour similar to that of natural tooth.1


Among various studies by different authors Triple neurectomy & implantation of proximal nerve ending into internal oblique done by Amidet et al appears to be goldstandard & most satisfying procedure with 100% success rate 15% have transient neuralgia. Prophylactic neurectomy is inferior to alternate careful identification and protection of nerves. At any time if a nerve is in the way of the repair or suspected to be injured its resection is universally recommended.


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