management of refractory neuropathic inguinodynia

1. Laparoscopic retroperitoneal triple
neurectomy
Management of Refractory Neuropathic
Inguinodynia
Georges Khalifeh
PGY4 General Surgery
Lebanese University

2.  Innervation of inguinal canal
 Laparoscopic anatomy Of the inguinal region
 Pain after inguinal hernia repair
 Laparoscopic retroperitoneal triple neurectomy

3. Innervation of inguinal canal
 Ilioinguinal nerve
 Genitofemoral nerve
 Iliohypogastric nerve
 Lateral femoral cutaneous nerve

6. Laparoscopic anatomy
Of the inguinal region

7.  Median umbilical ligament:
contains remnant of the
urachus.
 Medial umbilical ligament:
contains remnant of umbilical
arteries.
 Lateral umbilical ligament:
contains the inferior epigastric
vessels.
• The parietal peritoneum covers certain
structures forming ligaments, useful as
landmarks:

8. • The preperitoneal space is
the space bounded by the
peritoneum posteriorly and
the transversalis fascia
anteriorly.
• The space of Retzius is that
space between the pubis
and the bladder. The lateral
extent of this space is
named Bogros’ space.

10. • Dissection or tacking of preperitoneal
mesh should not take place inferior to
the iliopubic tract except in the
limited region of Cooper’s ligament.
• Dissection or tack placement
centrally beneath the iliopubic tract
will injure the femoral vein, artery,
and nerve, whereas placement
laterally may damage the lumbar
nerve branches.

11. • The inferior epigastric vessels give of two branches: the external spermatic vessel that travels in
the spermatic cord and the iliopubic branch.
• The latter may form a corona mortis. This vascular anomaly presents as a branch of either the
inferior epigastric or the external iliac that passes over the pubic tubercle en route to the
obturator system.
• Either the arterial or the venous system may be involved in this “triangle of death,” which may
cause significant hemorrhage during dissection and exposure of Cooper’s ligament or mesh fixation
with penetrating tacks.

14. Pain after inguinal
hernia repair:
a nightmare?

15. Classification
 Nociceptive
 Result of ligamentous or muscular trauma and inflammation
 Rest, NSAIDs and reassurance

16. Classification
 Neuropathic
 Direct nerve damage or entrapment
 Pharmacologic therapy and local steroid or anaesthetic injections

17. Classification
 Visceral
 Conveyed through afferent autonomic fibers
 Poorly localized

18. Risk factors for chronic postsurgical pain
 Preoperative
 Pain, moderate to sever, lasting more than 1 month
 Repeat surgery
 Psychological vulnerability (e.g., catastrophizing)
 Preoperative anxiety
 Female gender
 Younger age (adults)
 Genetic predisposition

19. Risk factors for chronic postsurgical pain
 Intraoperative
 Surgical approach with risk of nerve damage

20. Risk factors for chronic postsurgical pain
 Postoperative
 Pain (acute, moderate to severe)
 Radiation therapy to area
 Neurotoxic chemotherapy
 Depression
 Psychological vulnerability
 Anxiety

21. Chronic postoperative pain
 63% of inguinal hernia repair cases
 Meticulous nerve identification may prevent pain
 Notwithstanding, moderate-to-severe pain adversely affects physical activity, social
interactions, healthcare utilization, employment and productivity in 6% to 8% of patients

22. Post-herniorrhaphy inguinodynia
 Nociceptive, neuropathic and visceral elements
 Incidence independent of the method of hernia repair

23. Post-herniorrhaphy inguinodynia
 Revision of the repair
 Removal of mesh and fixation material
 Selective neurolysis or neurectomy
 Triple neurectomy with removal of meshoma +/- resection of paravasal nerves

24. Prevention
 Lap may have less pain than open mesh repair
 Mesh choice may matter
 Location and amount of fixation matters
 Multimodal pain management strategy
 Technique may matter: identify and reduce lipomas, pre-peritoneal fat...

25. Local nerve entrapment
 Acute neuropathic pain
 Dermatodermal distribution
 Mapping tests

26. Meralgia paresthetica
 Injury to the lateral femoral cutaneous nerve
 Persistent paresthesias of the lateral thigh

27. Initial treatment
 Rest
 Ice
 NSAIDs
 Physical therapy
 Local corticosteroid and anesthetic injection

29. Osteitis pubis
 Inflammation of the pubic symphysis
 Medial groin or symphyseal pain

30. Management
 Exclude hernia recurrence  CT / MRI
 Confirm diagnosis  bone scan
 Initial treatment

31. Initial treatment
 Rest
 Ice
 NSAIDs
 Physical therapy
 Local corticosteroid and anesthetic injection

32. Management
 Exclude hernia recurrence  CT / MRI
 Confirm diagnosis  bone scan
 Initial treatment
 Orthopedic surgery consultation
 Possible bone resection and curettage

33. Irrespective of treatment, the condition often takes 6
months to resolve.

34. Prevention
 Avoid the pubic periosteum when placing sutures and tacks

35. Failure of conservative treatment
Diagnostic laparoscopy
Intraabdominal
findings:
Adhesions or hernia
recurrence?
Adhesiolysis
Mesh hernia repair
Ye
s
TAPP dissection
1. Laterally: cutaneous nerve entrapment?
2. Medial: Canal/cord entrapment?
3. Remove offending tacks or meshs
4. Look for interstitial hernia / lipoma of the cord
No pathology
Ongoing symptoms OR previous repair was
open:
Open mesh excision / neurectomy

36. The more foreign body we place in our patients, the more
harm we cause

37. Case presentation
 A 70-year-old male with a history of lumbar disc herniation underwent
inguinal hernia repair using the Lichtenstein method
 He experienced mild pain at the early postoperative phase that disappeared 3
months after surgery.

38.  However, he revisited our hospital due to exacerbation of the pain 16 months
after surgery.
 The patient had walked with cane due to lumbar disc herniation since several
years ago but he was able to walk a long distance without any restriction
before inguinal hernia repair.
 However, he became unable to walk a long distance and walked very slowly
due to inguinodynia, which disturbed his daily life considerably.
 No abnormal findings were noted on inspection.

39. Dermatomal Mapping
Dermatomal mapping indicated
ilioinguinal and iliohypogastric nerve
problems.
Pain assessment by dermatomal mapping,
as described by Álvarez

40.  Tinel’s sign at the site of maximum tenderness was positive.
 Preoperative MRI showed the presence of lumber disc herniation but there
was no evidence of its aggravation.
 MRI did not reveal meshoma, recurrence, or other visceral causes

41. The pain was attributed to a neuropathic
cause for the following reasons:
1) dermatomal mapping suggested IIN and IHGN problems;
2) the site of maximum pain was slightly altered at each physical examination;
3) pain was evoked by specific movement, including extension of the inguinal
region and long-term sitting
4) pelvic MRI did not reveal meshoma, recurrence, or other visceral causes

42.  Nonsteroidal anti-inflammatory drugs and pregabalin were prescribed, but
these drugs did not decrease the pain.
 The effect of tramadol hydrochloride acetaminophen was also limited.
 Invasive conservative therapy was initiated

43. Trigger Point Block
Local anesthesia
 consisting of 10 mL 1% lidocaine and 10 mL 0.75% ropivacaine was injected
into the site of maximal pain (trigger point block; TPB), but a minimal effect
was noted.
 Subsequently, IIN and IHGN blocks were performed, but this treatment was
ineffective.

44.  The pain persisted for 3 months after the initiation of invasive conservative
therapy.
 Thus, surgical intervention was considered.

45. Anterior approach
VS
Lap Retroperitoneal Triple Neurectomy
 LRTN was planned for the following reasons:
1) mesh removal would be unnecessary
2) nerve resection at the level of the lumbar plexus would be preferable given
that the percutaneous IIN and IHGN peripheral blocks were not effective

46. Laparoscopic Retroperitoneal
Triple Neurectomy

48.  Under general anesthesia
 the patient was placed in the lateral decubitus position

49. Three-port method
A 12-mm transverse incision was made at
the midpoint between the iliac crest and
the costal margin, and the retroperitoneal
cavity was accessed.
Then, a 12-mm balloon trocar was
inserted, and insufflation of carbon
dioxide was initiated
Another 12-mm port and a 5-mm port
were inserted

50.  Retroperitoneal fat pads were dissected bluntly
 The quadratus lumborum and psoas muscles were exposed sufficiently

51. Blue-encircled
arrowheads
indicate the
ilioinguinal and
iliohypogastric
nerves, which
formed a common
trunk.
The asterisk
indicates the
quadratus
lumborum muscle

52. Green-encircled
arrowheads
indicate the
genital branch of
the genitofemoral
nerve coursing in
front of the psoas.
Arrows indicate
the ureter

53.  After identification of all three nerves, each nerve was resected after placing
a clip proximally and distally to close the neurilemmal sheath to prevent
neuroma formation

54. Yellow-encircled
and orange-
encircled
arrowheads indicate
the distal and
proximal stumps of
the common trunk
of the ilioinguinal
and iliohypogastric
nerves

55.  All resected nerve specimens were sent to the pathology laboratory for
histologic confirmation.

56. Gray-encircled
arrowheads indicate
the residual nerve
emerging from L2/3
and running toward
the inguinal region
 This nerve might be a branch of the lateral femoral
cutaneous nerve

57.  Dermatomal mapping on postoperative day 1 revealed numbness and
complete elimination of pain .

58. Dermatomal mapping on postop day 1
revealed numbness and complete
elimination of pain
.

59. 3 months after surgery
 Although the patient still uses a cane for gait due to lumbar disc herniation,
he has otherwise resumed normal life, without any restrictions

60. Conclusion
 Diagnosis of neuropathic pain by thorough preoperative assessment is also
vital for the success of this procedure because it is not effective for other
types of pain.
 A thorough understanding of the neuroanatomy of the inguinal nerves is
necessary to perform safe and effective surgery.

62. Methods
 This prospective cohort study conducted at the Lichtenstein Amid Hernia
Clinic at the University of California, Los Angeles between January 1, 2012
and October 31, 2015
 The study was approved by the University of California, Los Angeles
Institutional Review Board.

63. Inclusion criteria
 Inguinodynia for a minimum of 6 months,
 Significant pain severity with numeric pain score (NPS) of 6 or greater, and
 Impairment of activities of daily living.
 Pain was primarily neuropathic as determined by clinical history (shooting,
stabbing, burning, electrical sensations, hypo/hyperesthesia, and allodynia),
 Physical examination (positive Tinel’s sign)
 Dermatomal sensory mapping.

64. Imaging
All patients had preoperative
 Ultrasonography or
 Computed tomography or
 Magnetic resonance
To evaluate for alternative or concurrent etiologies (eg, meshoma, occult
recurrence, prostatitis, epididymitis, osteitis, degenerative disk disease, and
musculoskeletal or ligamentous injury).

65. Multidisciplinary evaluation and
treatment
All patients underwent multidisciplinary evaluation and treatment with a pain
specialist to confirm :
 Refractoriness to non-operative pharmacologic
 Behavioral
 Procedural intervention
 all received regional or paravertebral nerve blockade for diagnostic and
therapeutic purposes

66. 567 patients were evaluated for inguinodynia after prior groin herniorrhaphy
Of these, 62 patients met inclusion criteria and were selected for LRTN.

67. Exclusion criteria
 Hernia recurrence
 Predominantly non-neuropathic or meshoma pain
 Primary orchialgia
 Pain unrelated to prior surgical intervention
 Prior retroperitoneal surgery

68. Reasons for exclusion of the
remaining 505 patients

69.  .

70. Data collection
 A single physician collected data on days 0, 1, 90, and at 6-month intervals up
to 3 years post intervention.
 Dermatomal somatosensory mapping described by A´lvarez was performed :
 Preoperatively
 within the first 24 hours postoperatively
 postoperative day 30, and at all postoperative visits.

71. The Numeric Rating Scale
The Numeric Rating Scale (NRS-11) was used to quantify self-reported levels of
pain with
 0 = no pain
 1 to 3 mild pain without interference with daily activities
 4 to 6 moderate pain with significant interference
 7 to 10 severe disabling pain
13 Medication regimens and narcotic usage were assessed, and levels of activity
and disability were documented.

72. Operative neurectomy was offered after
…
 failure of extensive and multidisciplinary pharmacologic and interventional
treatment
 only patients with debilitating pain levels or significant activity impairment,
with numerical pain scores of 8.6 (range, 6 to 10).

73. Prior failed operative interventions

74. 62 patients received LRTN
 Mean operating time was 50 minutes.
 There were no conversions.
 The single intraoperative complication was a small laceration of the postero-
inferior diaphragm, which was closed without sequelae.
 Estimated blood loss was minimal, with no intraoperative transfusions of
blood or products in any patients.

75. Histopathologic examination
 Confirmation of triple neurectomy in 61 patients
 Quadruple neurectomy for lateral femoral cutaneous
involvement in 1 patient.

76. Numeric Rating Scale
Subjectively reported mean NRS were significantly decreased on postoperative
days:
 1 (3.6; P , .001)
 90 (2.3; P , .001)
 180 (2.1; P , .001)
 360 (1.8; P , .001)
 540 (1.5; P , .001)
 720 (1.5; P , .001)
 1,080 (1.1; P , .001)
compared with the preoperative value of 8.6

77. There were 3 patients lost to follow-up after a minimum of 1 year.
 Pain relief following operation brought improved quality of life.
 Narcotic dependence was decreased in 57 patients at 1 year postoperatively.
 Subjectively reported activity level increased in 58 patients as reflected by
their ability to resume daily and workplace activities.

78. Hypersensitivity & laxity
 20 patients (32%) reported hypersensitivity in the distribution of neurectomy
consistent with deafferentation.
 Hypersensitivity resolved within 4 weeks in 11 patients and within 6 months in
15 patients but has persisted over 1 year with diminished intensity in 5
patients.
 Nineteen patients have noted symptoms from lateral abdominal laxity caused
by partial denervation of the oblique muscles from loss of the IHN and IIN

79. Take home message
 Refractory neuropathic inguinodynia remains a challenging condition with
significant personal morbidity and cost to patients

80. Laparoscopic retroperitoneal triple
neurectomy
Effective treatment for the neuropathic component of inguinodynia
Advantages of LRTN as compared with open anterior triple neurectomy:
 More consistent retroperitoneal anatomy
 Reliable identification of the nerves
 avoidance of the prior surgical site scarring and mesh

81. Take home message
 It is an important and effective operative technique to address isolated or
predominantly neuropathic pain after inguinal hernia repair, and in the
absence of recurrence or meshoma
 LRTN is the preferred technique for definitive management of chronic
inguinal pain after preperitoneal repair or prior failed neurectomy.

82.  Thank you …