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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1498_Библиотеки_им_академика_М_И_Перельмана.pdf
42
D.C. Chen and P.K. Amid
Post-Herniorrhaphy Inguinodynia
While the rates of recurrence associated with inguinal hernia repair
dramatically decreased after “tension-free” methods became standard
practice, the incidence of postoperative inguinodynia remains a major
concern. According to a Danish nationwide study, the rate of post-
herniorrhaphy chronic pain is independent of the method of the hernia
repair (tissue repair, open mesh repair, or laparoscopic mesh repair) [
4 ] .
Based on the classi fi cation of pain by the International Association for
the Study of Pain (IASP), post-herniorrhaphy inguinodynia can be
broadly divided into nociceptive and neuropathic pain.
Nociceptive pain is caused by activation of nociceptors by nociceptive
molecules due to tissue injury or in fl ammatory reaction. These signals
are then transmitted to the brain via A-delta and C- fi bers. Nociceptive
pain can be reduced by gentle tissue handling and using local anesthesia
to reduce production of nociceptive molecules.
Neuropathic pain is caused by direct nerve injury such as myelin
undulation, myelin separation, axon crystallization, and other structural
changes of nerve fi bers due to direct contact of nerves with mesh and/or
nerve entrapment by sutures, staples, tacks, folded mesh, or meshoma [ 5 ] .
Neuropathic pain can be reduced from the reported range of 6–8% to less
than 1% by careful nerve handling to avoid destruction of the protective
layers of the nerves during open repair [ 6, 7 ] , by avoiding placement of
mesh in the parietal compartment of the preperitoneal space, by adequate
mesh fi xation, and by preventing mesh wrinkling and meshoma formation
during laparoscopic and open preperitoneal inguinal hernia repair [ 8, 9 ] .
Groin Neuroanatomy
There are three nerves within the inguinal canal (Fig. 4.1 ). The
ilioinguinal nerve is located over the spermatic cord, covered and protected
from the mesh by the investing fascia of the internal oblique muscle
(Fig. 4.2 ). This protective fascia should not be damaged by removing the
nerve from its natural bed. Removing the ilioinguinal nerve from its native
position over the cord and placing it below the inguinal ligament, which
was the teaching of a prior era, destroys the protective fascia of the nerve
and risks perineural scaring and direct contact of the nerve with mesh.
The genital branch of the genitofemoral nerve is located under the
cord (Fig. 4.1 ), covered and protected from direct contact with mesh by
43
4. Technique: Lichtenstein
the deep cremasteric fascia. Although small and dif fi cult 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 (Fig. 4.3 ). To assure
safety of the nerve, it must be kept with the spermatic cord while the cord
is separated from the inguinal fl oor using a blunt dissector such as peanut
under direct visualization. Grasping the cord with thumb and index fi nger
and bluntly fi nger dissecting this off the fl oor is excessively traumatic
and should be avoided. This may damage the deep cremasteric fascia
which can lead to perineural scaring and direct contact of the genital
nerve with the implanted mesh. In addition it results in direct contact of
the vas and sensory nerve fi bers of the testicle (paravasal nerve fi bers)
within the covering sheath of the vas (lamina propria of the vas) that can
lead to orchialgia [ 10 ] , azoospermia [ 11 ] , and dysejaculation.
The iliohypogastric nerve is located between the external and internal
oblique layers, covered and protected from mesh by the investing fascia
of the internal oblique muscle (Fig. 4.1 ). The key step to exposing the
Fig. 4.1. Neuroanatomy of the left inguinal canal. Pubic tubercle on the left.
44
D.C. Chen and P.K. Amid
Fig. 4.2. Left ilioinguinal nerve (A). Pubic tubercle on the left. Investing fascia
of the internal oblique muscle covering and protecting the nerve (B).
Fig. 4.3. Left genitofemoral nerve (A). Pubic tubercle on the left. The “blue”
line of the external spermatic vein (B).
45
4. Technique: Lichtenstein
iliohypogastric nerve is opening the anatomic cleavage between the
internal and external oblique layers high enough to expose the internal
oblique aponeurosis. This simple step readily exposes the iliohypogastric
nerve. The iliohypogastric nerve has an easily visible part over the
internal oblique aponeurosis and muscle (Fig. 4.4 ). There is also a hidden
segment that runs inferiorly and laterally within the internal oblique
muscle (Fig. 4.4 and dotted line in Fig. 4.1 ). This segment of the
iliohypogastric nerve is the most vulnerable neural structure of the
inguinal area because it is not visible within the operative fi eld [ 10 ] .
Suturing through the internal oblique muscle, or the so-called conjoined
tendon, for its fi xation to the inguinal ligament, fl at mesh, or plug has the
potential risk of injuring the intramuscular segment of the nerve with the
needle or entrapping it by the suture.
Operative Technique
The procedure is performed under local anesthesia [ 12 ] , which is our
preferred choice for all reducible adult unilateral and bilateral [ 2 ] inguinal
hernias. It is safe, simple, effective, economical, and without the normal
Fig. 4.4. Left iliohypogastric nerve. Pubic tubercle on the lower part of the left side.
46
D.C. Chen and P.K. Amid
side effects of general anesthesia such as nausea, vomiting, and urinary
retention. Furthermore, local anesthesia administered prior to making
the incision produces a preemptive and prolonged analgesic effect via
inhibition of the buildup of local nociceptive molecules [ 12 ] .
A 5–6 cm skin incision, which starts from the pubic tubercle and
extends laterally following a Langer’s line, provides excellent exposure
to both the pubic tubercle and the internal ring. The incision is carried
down through Scarpa’s fascia to the external oblique aponeurosis. The
external oblique aponeurosis is opened in the direction of its fi bers down
through the external ring. The lower leaf of the external oblique (the
inguinal ligament) is freed from the spermatic cord. The ilioinguinal
nerve can usually be identi fi ed coursing with the spermatic cord
immediately upon lifting the external oblique aponeurosis, and care is
taken to preserve this structure during exposure. The upper leaf of the
external oblique is then freed from the underlying internal oblique muscle
until the internal oblique aponeurosis is exposed (Fig. 4.1 ). The anatomic
cleavage between these two layers is avascular, and the dissection can be
performed rapidly and atraumatically. High separation of these layers
allows for visualization of the iliohypogastric nerve and internal oblique
aponeurosis. This dissection also creates ample space for insertion of a
suf fi ciently wide sheet of mesh that can overlap the internal oblique well
above the upper margin of the inguinal fl oor.
The cord with its cremaster covering is separated from the fl oor of the
inguinal canal and the pubic bone for a distance of approximately 2 cm
beyond the pubic tubercle (Fig. 4.1 ). The anatomic plane between the
cremasteric muscle and attachment of rectus sheath to the pubic bone is
avascular. Strictly dissecting within this plane avoids the risk of damaging
testicular blood fl ow. When lifting the cord, care should be taken to
include the ilioinguinal nerve, the easily visible blue external spermatic
vein, and the genital nerve with the cord. This assures that the genital
nerve, which is always in juxtaposition to the external spermatic vessels,
is securely preserved.
The internal ring is always explored to identify the presence of an
indirect hernia sac. The cremasteric muscle layer is opened anteriorly
and incised longitudinally approximately 3–4 cm at the level of the deep
ring to access the cremasteric compartment. Complete stripping and
resection of the cremasteric fi bers are unnecessary and can result in direct
exposure of the genital nerve, vas deferens, and paravasal nerves to the
mesh, resulting in chronic groin and testicular pain.
Indirect hernia sacs are identi fi ed and freed from the cord using the
electrocautery tip as a dissector with or without energy and gentle
47
4. Technique: Lichtenstein
traction. The sac is freed to a point beyond its neck and is inverted into
the properitoneal space without ligation. Because of mechanical pressure
and ischemic changes, ligation of the highly innervated peritoneal sac is
a major cause of acute postoperative pain. It has been demonstrated that
nonligation of the indirect hernia sac does not increase the chance of
recurrence . To minimize the risk of postoperative ischemic orchitis,
complete nonsliding scrotal hernia sacs are transected at the midpoint of
the canal, leaving the distal portion of the sac in place. However, the
anterior wall of the distal sac is incised to prevent postoperative hydrocele
formation. If the internal ring is too large, it can be tightened using one
or two Marcy Sutures placed on the transversalis fascia at the deep ring.
The fl oor of the inguinal canal inferomedial to the inferior epigastric
vessel is evaluated for evidence of a direct hernia. If large with a narrow
neck, the direct sac is inverted using a purse string suture. If large with a
wide base, the sac is inverted with an absorbable suture placed along the
transversalis fascia. For this purpose, the lower edge of the internal
oblique muscle should not be included in the suture under tension as in
the classic Bassini operation preserving the “tension-free” principle of
this repair. A thorough exploration of the groin is necessary to rule out
coexisting intraparietal (interstitial), low-lying spigelian, or femoral
hernias. The femoral ring is routinely evaluated via the space of Bogros
through a small opening in the canal fl oor.
A 7 × 15 cm sheet of mesh is used to repair the fl oor of the inguinal
canal. We prefer mono fi lament, macroporous, polypropylene meshes
because the mono fi lament structure does not perpetuate or harbor infection.
The medial corner of the mesh is tailored to its standard shape, (Fig. 4.5 )
which resembles the tracing of a footprint, with a lower sharper angle to fi t
into the angle between the inguinal ligament and the rectus sheath and an
upper wider angle to spread over the rectus sheath. With the cord retracted
upward, the sharper corner is sutured with a nonabsorbable mono fi la-
ment suture material or stapled to the rectus sheath above its insertion to
the pubic bone and overlapping the bone by 1–2 cm (Fig. 4.6 ). This is a
crucial step in the repair because failure to cover this bone with the mesh
can result in recurrence of the hernia. The periosteum of the bone is
avoided. This is continued as a continuous running suture or intermittent
staples attaching the lower edge of the mesh patch to the inguinal ligament
up to a point just lateral to the internal ring (Fig. 4.6 ). Suturing or stapling
the mesh beyond this point is unnecessary and could injure the femoral
nerve. If there is a concurrent femoral hernia, it can be fi xed using a
modi fi cation in which the mesh is also sutured to the Cooper ligament
1–2 cm below the suture line with the inguinal ligament in order to close
48
D.C. Chen and P.K. Amid
the femoral ring. Alternatively, the mesh can be tailored to have a triangular
extension from its lower edge. The lateral aspect of the triangular extension
is sutured to the Cooper ligament, and the body of the mesh is sutured to
the inguinal ligament along the dotted line (Fig. 4.5 ) obliterating the defect
in the femoral canal.
A slit is made at the lateral end of the mesh, creating two tails, a wider
one (two-thirds of the width) above and a narrower one (one-third of the
width) below. The wider upper tail is grasped with forceps and passed
toward the head of the patient from underneath the spermatic cord;
this positions the cord between the two tails of the mesh (Fig. 4.7 ). The
upper tail is crossed and placed over the lower tail and held with a
hemostat (Fig. 4.8 ). With the cord retracted downward and the upper leaf
of the external oblique aponeurosis retracted upward, the upper edge of
Fig. 4.5. Standard mesh: 7 cm × 15 cm ( top ). Modi fi ed mesh with a triangular
extension for the repair of a coexisting femoral hernia ( bottom ) .
49
4. Technique: Lichtenstein
Fig. 4.6. With the cord retracted upward, the lower edge of the mesh with a 2 cm
extension medial to the pubic tubercle is fi xed to the inguinal ligament. The
medial corner of mesh is fi xed to the insertion of rectus sheath on the pubic bone
away from the pubic tubercle.
the mesh patch is sutured in place with two interrupted absorbable sutures
or stapled, one to the rectus sheath and the other to the internal oblique
aponeurosis just medial to the internal ring (Fig. 4.8 ). Occasionally, the
course of the iliohypogastric nerve passes against the upper edge of the
mesh. In this case, a slit in the mesh will accommodate the nerve. If in
doubt, the nerve can be resected with proximal-end ligation to prevent
traumatic neuroma formation and implantation within the fi bers of
the internal oblique muscle to keep the stump of the nerve away from the
future scarring within the operative fi eld. Suturing or stapling the upper
edge of the mesh to the internal oblique muscle should be avoided to
prevent injuring the intramuscular segment of the iliohypogastric nerve.
Using a single nonabsorbable mono fi lament suture or staple, the
lower edges of each of the two tails are fi xed to the inguinal ligament just
lateral to the completion knot of the lower running suture, leaving
adequate space for the passage of the spermatic cord (Fig. 4.9 ). The
excess patch on the lateral side is trimmed, leaving at least 5 cm of mesh
beyond the internal ring. This is tucked underneath the external oblique
aponeurosis (Fig. 4.9 ). Fixation of the tails of the mesh to the internal
50
D.C. Chen and P.K. Amid
oblique muscle, lateral to the internal ring, is unnecessary and could
result in entrapment of the ilioinguinal nerve with the fi xation suture or
staple. The aponeurosis of the external oblique is then closed over the
cord with an absorbable suture. The skin may be closed with an absorbable
subcuticular suture or staples completing the repair.
Evidence-Based Medicine: The Role of the
Lichtenstein “Tension-Free” Hernia Repair
Since the introduction of the open “tension-free” hernioplasty in
1984, the operation has been evaluated and compared with other types of
hernia repairs in numerous studies with regard to postoperative pain,
Fig. 4.7. A slit is made at the lateral end of the mesh forming two tails. The
spermatic cord is placed in between the two tails.
51
4. Technique: Lichtenstein
postoperative time off work, complications, costs, and, most signi fi cantly,
recurrence rate. According to the 2009 European Hernia Guidelines
prepared by 14 renowned European hernia experts based on the review
of 324 published clinical trials, the Lichtenstein technique introduced in
1984 is currently the best evaluated and most popular of different open
mesh techniques. It is reproducible with minimal morbidity; it can be
performed in the outpatient setting under local anesthesia and has low
recurrence rates in long-term follow-up [ 13 ] . Results of nonexpert
surgeons and supervised residents using the Lichtenstein repair for
primary inguinal hernias showed comparable excellent results
underscoring the ease, safety, and reproducibility of this technique [ 14 ] .
A Cochrane review of 20 randomized trials comparing Lichtenstein
repair to tissue repair demonstrated a shorter length of hospital stay,
quicker return to usual activities, less chronic pain, and signi fi cantly
Fig. 4.8. With the cord retracted downward, the tails of the mesh are crossed and
held in place with a clamp. The upper edge of the mesh is sutured or stapled to
the internal oblique aponeurosis.