The inguinal canal is an oblique space measuring 4 cm in length that lies above the medial

half of the inguinal ligament.

At its medial end there is a triangular opening, called the external inguinal ring, that lies
above and lateral to the pubic crest.
The internal inguinal ring is located at the lateral end and represents an opening within the
transversalis fascia.
The boundaries of the internal inguinal ring are superiorly the transverus abdominis arch,
inferiorly the iliopubic tract, and medially the inferior epigastric vessels.
The thickened fascia overlying the epigastric vessels is called Hesselbach’s ligament.

The internal inguinal ring is located 1 cm above the femoral artery pulse or midway between
the anterior superior iliac spine and pubic tubercle.

The relationships of the inguinal canal are as follows:

Anterior: external oblique fascia along the entire length with contribution from the
internal oblique fascia at the lateral one third.
Posterior: fusion of the transversalis fascia and the transversus abdominis fascia.
Inferior (floor): the inguinal ligament and its shelving edge and medially the lacunar
ligament of Gimbernat.
Superior (roof): the arch formed by the internal oblique and transversus abdominis muscle
(conjoint tendon).

The contents of the inguinal canal include the following:

Male:
The spermatic cord travels through the inguinal canal and consists of three nerves, three
arteries, and three other structures.
The nerves are the ilioinguinal nerve, the genital branch of the genitofemoral nerve, and the
sympathetic nerves.
The three arteries are the spermatic artery from the aorta, the artery to the vas deferens
from the superior vesicle, and the cremasteric artery from the deep epigastric artery.
The remaining other three structures include the vas deferens, the pampiniform venous
plexus, and the lymphatic channels.
The cord has three coverings—the outer external spermatic fascia, the middle cremasteric
muscle layer, and the inner internal spermatic fascia—which are derived from the external
oblique fascia, internal oblique muscle, and transversus fascia, respectively.

Female:
The round ligament of the uterus, ilioinguinal nerve, and genital branch of the genitofemoral
nerve.
Nyhus classification system

TYPE
I Indirect hernia; internal abdominal ring normal; typically in infants, children, small
adults
II Indirect hernia; internal ring enlarged without impingement on the floor of the inguinal
canal; does not extend to the scrotum
IIIa Direct hernia; size is not taken into account
IIIb Indirect hernia that has enlarged enough to encroach upon the posterior inguinal wall;
indirect sliding or scrotal hernias are usually placed in this category because they are
commonly associated with extension to the direct space; also includes pantaloon
hernias
IIIc Femoral hernia
V Recurrent hernia;
Modifiers A–D are sometimes added, which correspond to indirect, direct, femoral, and
mixed, respectively

o The mid-inguinal point (situated midway between the anterior superior iliac spine and the
pubic symphysis)
o The midpoint of the inguinal ligament (i.e. midway between the anterior superior iliac spine
and the pubic tubercle).
Borders and contents of the A. triangle of doom and B. triangle of pain.

o The triangle of doom is bordered medially by the vas deferens and laterally by the vessels of
the spermatic cord. The contents of the space include the external iliac vessels, deep
circumflex iliac vein, femoral nerve, and genital branch of the genitofemoral nerve.
o The triangle of pain is a region bordered by the iliopubic tract and gonadal vessels, and it
encompasses the lateral femoral cutaneous, femoral branch of the genitofemoral, and
femoral nerves.
o The circle of death is a vascular continuation formed by the common iliac, internal iliac,
obturator, inferior epigastric, and external iliac vessels.
o The ilioinguinal nerve
 Emerges from the lateral border of the psoas major and passes obliquely across the
quadratus lumborum.
 At a point just medial to the anterior superior iliac spine, it crosses the internal
oblique muscle to enter the inguinal canal between the internal and external oblique
muscles and exits through the superficial inguinal ring.
 The nerve supplies the skin of the upper and medial thigh.
 In males, it also supplies the penis and upper scrotum,
 In females, it also supplyies the mons pubis and labium majora

o The iliohypogastric nerve

 Arises from T12–L1 and follows the ilioinguinal nerve.
 After the iliohypogastric nerve pierces the deep abdominal wall in its downward
course, it courses between the internal oblique and transversus abdominis, supplying
both.
 It then branches into a lateral cutaneous branch and an anterior cutaneous branch,
which pierces the internal oblique and then external oblique aponeurosis above the
superficial inguinal ring.
 A common variant is for the iliohypogastric and ilioinguinal nerves to exit around the
superficial inguinal ring as a single entity.

o The genitofemoral nerve

 Arises from L1–L2, courses along the retroperitoneum, and emerges on the anterior
aspect of the psoas.
 It then divides into the genital and femoral branches.
 The genital branch remains ventral to the iliac vessels and iliopubic tract as it enters
the inguinal canal just lateral to the inferior epigastric vessels.
 In males, it travels through the superficial inguinal ring and supplies the scrotum and
cremaster muscle.
 In females, it supplies the mons pubis and labia majora.
 The femoral branch courses along the femoral sheath, supplying the skin anterior to
the upper part of the femoral triangle.

o The lateral femoral cutaneous nerve

 Arises from L2–L3, but emerges from the lateral border of the psoas muscle at the
level of L4.
 It crosses the iliacus muscle obliquely toward the anterior superior iliac spine.
 It then passes inferior to the inguinal ligament where it divides to supply the lateral
aspect of the thigh.
The open repair of an inguinal hernia
How would you distinguish a direct from an indirect inguinal hernia?

• Anatomically: A direct inguinal hernia protrudes through the posterior wall of the inguinal canal
medial to the inferior epigastric artery, whereas an indirect hernia emerges from the deep inguinal
ring lateral to it.

• Clinically: An indirect inguinal hernia may be controlled by applying pressure on the abdominal wall
at the site of the deep inguinal ring – surface marking: 1.5 cm above the midpoint of the inguinal
ligament (midpoint of a line drawn from the pubic tubercle to the anterior superior iliac spine).

What is the difference between an obstructed and a strangulated hernia?

o An obstructed hernia contains obstructed but viable bowel, whereas a strangulated hernia
may contain non-viable bowel since its venous drainage is compromised.

What pre-operative measures should be taken before the repair of an inguinal hernia?

• Consider general versus local anesthetic.

o The procedure under a local anesthetic is generally not advised in the anxious patient and in
the obese patient.
o It is contraindicated in suspected strangulated hernia (where a more extensive dissection
may be required).

• Consider an open versus laparoscopic repair.

o Laparoscopic repairs are generally chosen for bilateral or recurrent hernia.

 Two units of blood should be cross-matched

 Perioperative intravenous antibiotics (e.g. Cefotaxime and Metronidazole) should be given in
cases of strangulated hernia.

• The correct side should be marked.

How would you perform the open repair of an inguinal hernia?

Position
o This is supine.
o The patient is prepared and draped from his xiphoid process to the mid-thigh region.

Incision
o A groin incision is performed approximately 3 cm above and parallel to the medial two-thirds
of the inguinal ligament.

The layers traversed are:

o Skin
o Subcutaneous fat
o Scarpa’s fascia
o External oblique (dividing of which opens the inguinal canal)

Procedure
o The spermatic cord is located within the canal and separated from the hernial sac (thus
carefully preserving the vas deferens).
o The sac is opened in indirect hernias (or directly reduced in direct) its contents inspected and
reduced, and then transfixed at the deep ring.
• The Bassini repair: This approximates the conjoint tendon to the inguinal ligament from the pubic
tubercle to the deep ring.
• The Liechtenstein repair: A prosthetic mesh (e.g. polytetrafluoroethane, PTFE) is sutured from the
pubic tubercle to the inguinal ligament and the conjoint tendon, splitting to enclose the spermatic
cord (a tension-free repair). This is the commonest method of repair.
• The Shouldice repair: A modification of the Bassini repair using a four-layer closure thereby
doubling the transversalis fascia.

Closure
o The anterior abdominal wall is then closed in layers.

What are the specific complications associated with the repair of an inguinal hernia?

Immediate
o Haemorrhage
o Injury to the ilioinguinal nerve

Early
o Wound infection
o Ischemic orchitis

Late
o Recurrence

What is “Jenkins’ rule”?

o “Jenkins rule” describes the requirement of suture bites 1 cm in thickness and 1 cm apart. It
is normal to require a length of suture 4_ the length of the wound and it is also important to
have the correct suture tension during closure to prevent wound dehiscence.

Describe a Kocher’s incision

o This is 2.5 cm below and parallel to the right costal margin.

The layers in this incision are:

o Skin
o Subcutaneous fat
o Scarpa’s fascia
o Rectus sheath
o Rectus abdominus
o Transversalis fascia
o Extra-peritoneal fat
o Peritoneum

o Groin pain following an inguinal hernia repair is much more common than recurrence and
has occurred at incidence as high as 29%–76% in several series.
o Transient pain with mild numbness inferior to the incision is common.
o Persistent, intense pain and loss of sensation suggest nerve injury or entrapment.
o Nerve injuries during inguinal hernia repair can occur secondary to entrapment,
electrocautery, and/or transection.
o The most commonly injured nerves with laparoscopic inguinal hernia are genitofemoral
and lateral femoral cutaneous may occur from tack placement
o The most commonly injured nerves with open inguinal hernia repair are ilioinguinal,
genital branch of the genitofemoral, and iliohypogastric.
o Mesh inguinodynia, or post herniorrhaphy pain syndrome, has been reported to result from
an inflammatory response to mesh or resultant scar tissue, or both.
o Before the hernia repair is begun, local anesthesia is administered.
o Either 1% lidocaine or a mixture containing 1% lidocaine, 0.25% Marcaine, and
bicarbonate solution can be used.
o First the ilioinguinal nerve is infiltrated. This is located approximately 1 cm medial
and inferior to the anterior superior iliac spine.
o Intradermal and the subcutaneous tissues are infiltrated at the site of the proposed
incision.
o The skin and the subcutaneous tissue are incised with a no. 10 scalpel.
o Two branches of the superficial epigastric veins are invariably encountered; they are
clamped, divided, and ligated with 3-0 silk sutures.
o A self-retaining Weitlaner retractor is placed.
o At the lateral end of the incision the subcutaneous tissue is further incised until the
external oblique fascia is identified.
o The rest of the subcutaneous tissue is incised down to the level of the external
oblique fascia.
o The self-retaining retractor is repositioned.
o The external ring is identified on the medial aspect. With a no. 15 scalpel an incision
is made into the external oblique fascia along its fibers.
o The edges of this incision are grasped with Kelly clamps, and the external oblique
fascia is carefully dissected free from the underlying areolar tissue and both the
ilioinguinal and genitofemoral nerves.
o While these two nerves are protected, the inguinal canal is opened by extending the
incision toward the external ring.
o The two nerves are then carefully freed, preserved, and retracted out of the way.
o The entire cord needs to be carefully freed from the floor of the inguinal canal. This
is best started at the level of the pubic tubercle.
o The operator grasps the cord structures with the left hand, and using the right index
finger palpates the pubic tubercle and gently elevates the cord using a combination
of blunt and sharp dissection.
o A quarter-inch Penrose drain is placed around the cord to facilitate retraction.
o The cremasteric muscles are divided, and the cremasteric artery is ligated to
carefully delineate the internal ring.
o Particular care is taken to avoid injuring the inferior epigastric vessels that are
present on the medial border of the internal ring.
o To identify the indirect sac, dissection is commenced on the anterolateral aspect of
the cord.
o First, the spermatic coverings arising from the internal oblique and the transversus
muscle are divided.
o A shiny white sac is identified, grasped with hemostats, and dissected free from the
cord structures.
o The sac is dissected proximally toward the internal ring.
o The sac needs to be opened to inspect its contents and to exclude the presence of a
sliding hernia
o If the distal end of the sac is not visualized, it can be transected at any convenient
location along the spermatic cord.
o The distal end is left open to allow drainage.
o If the sac is devoid of any abdominal contents, it is twisted and suture ligated at the
level of the internal ring with 2-0 absorbable sutures.
 o If, on the other hand, a sliding hernia is present, the sac is trimmed to the level of
the sliding structure and closed with continuous 2-0 absorbable sutures.
o After the indirect sac has been resected, the internal ring is evaluated.
o If it is widened due to the presence of the hernia sac and its contents, it can be
reconstructed with continuous or interrupted 3-0 polypropylene sutures.
o Once the internal ring is refashioned, it should barely admit the tip of the surgeon’s index
finger.
o The internal ring repair should not be made too tight because this can compromise testicular
blood supply.
o Attention is now directed toward repairing the floor of the inguinal canal.
o Several methods of repairs are described here.

Bassini Repair

o The conjoined tendon is retracted upward, and the aponeurosis of the transversus abdominis
muscle is approximated to the iliopubic tract that lies adjacent to the inguinal ligament with
several interrupted 3-0 silk sutures.
o The second layer of the repair involves suturing the conjoined tendon to the inguinal
ligament with interrupted 2-0 silk sutures. This suture line extends from the pubic tubercle to
the medial border of the internal ring. If during this layer of repair a great deal of tension is
noted, several small relaxing incisions can be made in the anterior rectus sheath.
o Several sutures can be used to approximate the conjoined tendon to the inguinal ligament
proximal to the cord.
o However, care must be taken to not constrict the cord.

McVay Repair

o This is the technique used commonly when there is a large direct inguinal hernia. The
attenuated posterior inguinal wall that consists only of thin transversalis fascia is excised,
revealing the underlying preperitoneal connective tissue. The segment of posterior wall that
is attached to Cooper’s ligament should also be excised even though it may appear to be
strong.
o The defect after excision of all the attenuated layers should reveal the preperitoneal
connective tissue, Cooper’s ligament, pectineus muscle fascia, external iliac and inferior
epigastric vessels, and femoral sheath. To allow for tension-free reconstruction of the
posterior inguinal wall, a 6- to 7-cm relaxing incision is made in the anterior rectus sheath.
There are numerous eponyms associated with this relaxing incision, which brings the
transversalis fascia down to Cooper’s ligament for suturing and reconstructing the inguinal
canal.
o Starting at the pubic tubercle, the strong edge of the transverse abdominis aponeurosis is
sutured to Cooper’s ligament with interrupted 3-0 polypropylene sutures until the femoral
vein is reached. The next suture placed is referred to as the transition suture because the
transversus abdominis aponeurosis is now sutured to the anterior femoral sheath rather
than to Cooper’s ligament. From this transition suture the transversalis fascia is
approximated to the anterior femoral sheath to the level of the internal ring. The rectus
abdominis prevents development of a hernia at the defect in the anterior rectus sheath
created by the relaxing incision. The cord is replaced within the inguinal canal.

Shouldice Repair

o With a no. 15 scalpel an incision is made in the transversalis fascia until the preperitoneal fat
can be seen. This incision is extended from the internal ring to the pubic tubercle. The
resulting upper transversalis fascia flap is bluntly separated from the underlying pre-
peritoneal fat until the thickened edge of the rectus sheath on the deep aspect is visualized
and grasped with several Allis clamps. The repair involves placing four lines of sutures. The
 first suture line is started at the pubic tubercle using 3-0 continuous polypropylene, and the
white line is approximated to the free edge of the inferior transversalis fascial flap. At the
internal ring the suture is tied and then continued medially by approximating the free edge
of the superior flap to the shelving edge of the inguinal ligament. When the pubic tubercle is
reached, the suture is tied and divided. The third suture line is started at the level of the
internal ring where the conjoined tendon is approximated to the inguinal ligament and tied
when the pubic tubercle is reached.
o Using the same suture, the fourth suture line attaches these same structures to one another
and is tied at the level of the internal ring. The cord is replaced within the inguinal canal, and
the external inguinal aponeurosis is reapproximated with continuous 2-0 absorbable sutures.
o The subcutaneous tissue is closed with interrupted 3-0 absorbable sutures. The skin is
approximated with subcuticular 4-0 absorbable sutures.

Lichtenstein Tension-Free Mesh Repair

o If there are any discrete defects within the transversalis fascia, the herniating sac is inverted
and the edges of the defect are approximated with interrupted 3-0 polypropylene sutures.
For a tension-free mesh repair, the length and width of the floor of the inguinal canal are
measured.
o The polypropylene (Marlex) mesh is fashioned to the shape of the floor of the inguinal canal.
o An opening is fashioned on the lateral aspect of the polypropylene mesh to allow it to pass
around the cord structure at the level of the internal ring. The polypropylene mesh is secured
to the floor with continuous 3-0 polypropylene monofilament sutures starting at the pubic
tubercle. The retracted ilioinguinal nerves are placed over the mesh. The wound is irrigated
and hemostasis achieved, particularly of the cord structure. At this point the patient, if
awake, can be asked to cough to test the integrity of the repair.

CLOSURE

o The external oblique fascia is re-approximated starting at the external ring using 2-0
absorbable sutures.
o The subcutaneous tissue is irrigated, and any debris is removed.
o The skin is approximated with subcuticular 4-0 absorbable sutures, and the testis is gently
drawn into the scrotum to avoid iatrogenic undescended testis.

o Laparoscopic hernia repair is appropriate for femoral hernias and indicated for bilateral or
recurrent inguinal hernias.
o Principal laparoscopic methods include the transabdominal preperitoneal (TAPP) repair, the
totally extraperitoneal (TEP) repair, and the less commonly performed intraperitoneal onlay
mesh (IPOM) repair.
o A total extraperitoneal repair (TEP) uses an infraumbilical port and a balloon dissector in the
preperitoneal space to expose the inguinal canal and hernia.
o A transabdominal preperitoneal repair (TAPP) uses an infraumbilical port to gain access to
the peritoneum. A peritoneal flap is created to expose the hernia.
o The lateral edge of the dissection is the anterior superior iliac spine in both approaches.
o The hernia is reduced, and a large mesh is placed over the defect.
o Important landmarks are the inferior epigastric vessels running along the edge of the rectus
muscle dividing indirect and direct hernias.
o Tacks are placed medial to Cooper’s ligament to secure the mesh in place.
o No tacks should be placed inferior to the iliopubic tract because the femoral branch of the
genitofemoral nerve and the lateral femoral cutaneous nerve are located lateral and inferior.
Femoral hernia repair
ANATOMY
o Relevant to this area is the femoral sheath, a funnel-shaped channel that is formed
anteromedially by the continuation of the transversalis fascia, posteriorly by the fascia
overlying the psoas and pectineus muscles, and laterally by the iliacus fascia. In the thigh, the
femoral sheath fuses with the adventitia of the femoral vessels about 3 cm below the
inguinal ligament.
o The sheath is divided into three compartments by the septa:
1. The lateral compartment, occupied by the femoral artery;
2. The intermediate compartment, occupied by the femoral vein; and
3. The medial compartment, called the femoral canal, which is empty and through which
femoral hernia may pass.
o The femoral canal is about 1 to 2 cm long and contains lymph nodes (of Cloquet), which drain
the penis or clitoris, connective tissue and lymph vessels and communicates superiorly with
the retroperitoneal space by an opening referred to as the femoral ring.

o The boundaries of the femoral canal are as follows:

 Anterior: inguinal ligament (Poupart’s ligament).
 Posterior: pectineal ligament (Cooper’s ligament).
 Lateral: femoral vein.
 Medial: edge of the lacunar (Gimbernat’s) ligament.

o In about 10% of cases, the abnormal obturator artery passes adjacent to the lacunar
ligament and may be injured during division of the lacunar ligament.
o The femoral canal normally contains fat and a lymph node called Cloquet’s node.

o The femoral triangle is bound:

Superiorly by the inguinal ligament.
Medially by the medial border of the adductor longus muscle.
Laterally by the medial border of the sartorius muscle.
o Its floor is formed by the pectineus and adductor longus muscles medially
and iliopsoas muscle laterally.
o Its roof is formed by the fascia lata, except at the saphenous opening where it is formed by
the cribriform fascia.

o The femoral triangle is important as a number of vital structures pass through it, right under
the skin.
o The following structures are contained within the femoral triangle (from lateral to medial):
1. Femoral nerve and its (terminal) branches.
2. Femoral sheath and its contents:
 Femoral artery and several of its branches.
 Femoral vein and its proximal tributaries (e.g., the great saphenous and deep
femoral veins).
 Deep inguinal lymph nodes and associated lymphatic vessels.
Why are femoral hernia more common in women?

o These are more common in women because the inguinal ligament makes a more oblique
angle onto the pubis in females.
o The increased intra-abdominal pressure during pregnancy stretches the transversalis fascia
and may also be a contributing factor.

What usually herniates into the femoral canal?

o It is normally the mesentery that herniates, although it also may contain small bowel.
o In 30% of strangulated hernia there may be a functional obstruction with only a part of the
lumen obstructed. This is known as a “Richter’s hernia”.
o Due to the high risk of strangulation, surgery is always recommended.

How do you differentiate between inguinal and femoral hernia?

This can be difficult:
Anatomically
o A femoral hernia is below and medial to the pubic tubercle.
Clinically
o A femoral hernia is usually small, painful and irreducible; there is usually no cough impulse or
audible bowel sound.

What surgical options do you know for the repair of a femoral hernia?

There are three approaches to the hernia:

1. Low or crural approach (Lockwood) – used for elective and acute cases
 2. Extra-peritoneal (modified McEvedy)
3. High or inguinal approach (Lothestein) – interferes with inguinal canal

Each technique has the principle of dissection of the sac with reduction of its contents, followed by
ligation of the sac and closure between the inguinal and pectineal ligaments.
The most commonly used and simplest approach is the crural approach although this does not allow
easy visualization of strangulated bowel.

How do you perform a repair of a strangulated femoral hernia?

Pre-operatively General anesthetic and antibiotics are given (e.g. a Cephalosporin and
Metronidazole).

Position
This is supine with the groin and abdomen prepared and draped.

Incision
o A 6-cm transverse incision is made directly over the hernia (usually 2 cm below inguinal
ligament).
o The sac is identified. If irreducible the neck may be opened to reveal the contents and
viability of the bowel inspected.
o Warming of the bowel can lead to a decision if unsure of viability.
o Ischemic bowel should NOT be returned to the abdomen and should be resected with end-
to-end anastomosis via a lower midline laparotomy.
o If unable to reduce the hernia then the lacunar ligament may be cut (watch for the obturator
artery which sits behind).
o The sac is then reduced and the neck transfixed using Vicryl suture, repair of the hernia
opening is performed with nylon sutures between the medial inguinal and pectineal
ligaments (take care to avoid the femoral vein laterally).

Closure
The wound is closed in layers.

What are the specific complications of surgery?

Immediate
• Bowel ischemia if there is reduction en masse or rough handling of the bowel
• Damage to femoral vein

Early
• Infection

Late
• Recurrence