Genitofemoral neuralgia is a common cause of lower abdominal and pelvic pain. Genitofemoral nerve block is a simple technique that can produce dramatic relief for patients with genitofemoral neuralgia. If a patient reports pain suggestive of genitofemoral neuralgia that does not respond to genitofemoral nerve blocks, a diagnosis of lesions more proximal in the lumbar plexus or an L1 radiculopathy should be considered. Patients with a positive response to genitofemoral nerve block should be considered for ultrasound-guided genitofemoral nerve ablation as this technique may provide long-term pain relief.
At Pain Spa Dr. Krishna performs genitofemoral nerve block under real time ultrasound guidance, using state of the art equipment. This ensures 100% accuracy and our complication rates are extremely low.
Because of the course of the genitofemoral nerve, it is at risk of injury from the lower abdominal incision (appendectomy, inguinal herniorrhaphy) or trocar insertion performed in laparoscopic surgery. Patients with neuropathic pain following injury to the nerve may present with groin pain that may extend to the scrotum or testicle in men, labia in women, and the medial aspect of the thigh.
The genitofemoral nerve arises from fibers of the L1 and L2 nerve roots. It passes through the substance of the psoas muscle, where it divides into a genital branch and a femoral branch. The femoral branch passes beneath the inguinal ligament along with the femoral artery and provides sensory innervation to a small area of skin on the inside of the thigh. The genital branch passes through the inguinal canal to provide innervation to the round ligament of the uterus and labia majora in women. In men, the genital branch of the genitofemoral nerve passes with the spermatic cord to innervate the cremasteric muscles and provide sensory innervation to the bottom of the scrotum.
The genitofemoral (L1–L2) nerve passes through and along the anterior surface of the psoas major muscle, and it divides into genital and femoral branches above the inguinal ligament. Its genital branch travels with the spermatic cord and innervates the genitalia inferior to the area supplied by the ilioinguinal nerve.
Genitofemoral nerve block is used as a diagnostic and therapeutic tool in the management of groin pain and pain in the inguinal and scrotal regions. It is used to discriminate peripheral neuropathies from radiculopathies, as well as to treat both chronic and acute groin pain. In addition, it may help to predict the outcome of procedures like nerve ablations (pulsed radiofrequency) and neurolysis.
In patients with chronic groin pain post surgery, a genitofemoral nerve block may provide sustained analgesia where conservative therapies have failed.
Contraindications include allergy to the local anesthetics, infection at the site of injection and anti coagulant therapy.
While genitofemoral nerve block is generally a safe procedure, complications may occur as with any other injections. Bleeding and hematoma formation can occur, though this is more likely in patients with any existing blood dyscrasia or those on anticoagulants. Infection is an important risk and can be minimized by maintaining a sterile technique. The peritoneum lies just below the fascia and is therefore at risk for penetration. This may subsequently result in peritonitis, bowel perforation, or fistula formation. Other complications include paresthesias of the lower limb, intravascular injection, or inadvertent femoral nerve block.
Ultrasound guided genitofemoral nerve block can be of diagnostic as well as therapeutic benefit. Use of ultrasound allows real-time soft tissue imaging, greatly improving the success of the genitofemoral nerve block. It allows reduction in the volume of local anesthetic used and prevention of potential injury to adjacent structures.
Color Doppler may be used to aid in the identification of this point of transition between the femoral and external iliac arteries. When this point of transition is identified, the inguinal canal should be visible just above the external iliac artery, appearing as an ovoid structure containing tubular structures including the spermatic cord in males and the round ligament in women.