GENITOFEMORAL AND ILIOINGUINAL NEURALGIA AFTER LAPAROSCOPIC VERSUS OPEN INGUINAL HERNIORRHAPHY
Narouze, S.N.; Zakhary, E.; Basali, A.
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 right inguinal hernia repair 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 he 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.
Discussion: There are various surgical herniorrhaphy techniques that can be categorized in two main groups: an open approach and a laparoscopic approach.
Upon first introduction of laparoscopic herniorrhaphy, decreased nerve injury rates were reported. However as laparoscopic herniorrhaphy became a more common procedure and the number of procedures performed increased, the reported rates of complications and nerve entrapment increased as well.
Laparoscopic herniorrhaphy tends to spare the ilioinguinal and the iliohypogastric nerves compared to open hernia repair. However, the risk of injury to the lateral femoral cutaneous, genitofemoral, and femoral nerves is higher than with open heniorrhaphy.
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 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. 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, non-steroidal 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.
1- Neurologic Clinics 1999; 17(3): 655-67 2- Surgical Endoscopy 1999; 13(9): 878-81 3- Surgical Clinics of North America 2000; 80(1): 1-24 4- Surgical Endoscopy 2000; 14(8): 731-5
Saturday, December 22, 2007
Friday, December 21, 2007
Subscribe to:
Comments (Atom)