INGUINAL CANAL AND CLINICAL ANATOMY - PowerPoint Presentation

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INGUINAL CANAL AND CLINICAL ANATOMY

Presented by:

Dr. Masooma Syed

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INGUINAL REGIONThe

inguinal region

(groin) extends between the ASIS and pubic tubercle.

It is an important area anatomically and clinically.

Anatomically because it is a region where structures exit and enter the abdominal cavity.

Clinically because the pathways of exit and entrance are potential sites of herniation

.

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INGUINAL LIGAMENT AND ILIOPUBIC TRACT

Thickened fibrous

bands, or

retinacula,

occur in

relationship to

many joints that have a wide range of movement to

retain structures

against the skeleton during the various positions

of

the

joint

.

The

inguinal ligament

and

iliopubic tract

,

extending from the ASIS to the

pubic tubercle,

constitute a

bilaminar anterior (

flexor

) retinaculum of the hip

joint.

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The retinaculum spans the sub inguinal space, or

pelvifemoral space

through which pass the flexors of the hip and neurovascular structures serving much of the lower limb

This

space is divided by

the ilioinguinal

ligament/arch into two parts:

(

a) Large lateral part called

lacuna musculorum

.

(

b) Small medial part called

lacuna vasculorum

.

The iliacus and psoas muscles, and femoral and

lateral cutaneous

nerves of thigh pass through the

lacuna musculorum

behind the fascia iliaca.

The external iliac vessels in abdomen become

femoral vessels

as they pass through the medial part of the

subinguinal space—the

lacuna vasculorum

.

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Inguinal ligament(poupart’s/groin) ligament

A

thick, fibrous band

extending from ASIS to

the pubic tubercle.

lies beneath

the fold of groin.

Formed by the lower-free border of the external oblique aponeurosis, which is thickened and folded backward on itself.

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Extension

Lacunar Ligament (or Gimbernat’s Ligament)

From the medial end the deep fibres of the inguinal

ligament curve

horizontally backward to the medial part of the

pecten pubis

forming lacunar ligament.

This

ligament is

triangular in shape with apex attached to the pubic tubercle. Its sharp lateral edge forms the medial boundary of the femoral canal , which is the site of production of a femoral hernia.

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Pectineal

Ligament (Ligament of Cooper)

It is the extension of the posterior part of the

lacunar ligament

along the pecten pubis up to the

iliopectineal eminence

.

Reflected

Part of Inguinal Ligament

The superficial fibres from the medial end of the inguinal ligament expand upward and medially to form this ligament.It lies behind the superficial inguinal ring and in front of the conjoint tendon. Its fibres interlace with those of its counterpart of the opposite side at the linea alba.It can be called as the third crus of the superficial inguinal ring.

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The iliopubic tractIt is

the thickened inferior margin

of the

transversalis fascia, which appears as a

fibrous

band

running parallel

and posterior (deep) to the inguinal

ligament.

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Seen in the place of the inguinal ligament when the inguinal region is viewed from its internal (posterior) aspect (e.g., during laparoscopy),

It reinforces the posterior wall and floor of the inguinal canal as it bridges the structures traversing the subinguinal space

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Myopectineal orifice

The inguinal ligament and iliopubic tract span an area

of innate

weakness in the body wall in the inguinal region

called the

myopectineal

orifice

(Fruchaud, 1956).

This

weak area occurring in relation to structures traversing the body wall, is the site of direct and indirect inguinal and femoral hernias

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INGUINAL CANAL

A musculo-aponeurortic tunnel,4 cm in length.

Extends from the deep inguinal ring to superficial inguinal ring.

Its directed downwards , forwards and medially above and parallel with the medial half of the inguinal ligament.

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Inguinal RingsDeep Inguinal Ring

I

s

an oval opening in the

fascia transversalis

lies about 1.25 cm (1/2 inch) above

the midinguinal

point. From its margins, the fascia transversalis is prolonged into the canal like a sleeve, the internal spermatic fascia , around the structures that pass through the ring.

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Superficial Inguinal Ring

is a triangular gap in

the aponeurosis

of external oblique

lies above

and lateral

to the pubic crest

.

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The pubic crest forms the base of the triangle.

The sides of

the triangle are called

crura

.

They meet laterally

to form an obtuse apex. Near the apex, the two crura are united by the intercrural fibres.

It

is 2.5 cm long and 1.2 cm broad (at the base

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Boundaries of the inguinal canal

Anterior wall

(a) Skin

(b) Superficial fascia

(c) External

oblique aponeurosis.

(d) Internal oblique muscle fibres, in

lateral

one-third. This wall is strongest where it lies opposite the weakest part of posterior wall, that is deep inguinal ring

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Posterior wall: It is formed from deep to superficial by:

(a) Fascia transversalis, in the whole extent

(b) Conjoint tendon, in medial two-third

(c) Reflected part of the inguinal ligament, in

medial-most part.

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Roof:

It is formed by the lower arched fibres

of

internal

oblique and transversus

abdominis

muscles

.

Floor

: It is formed by:(a) Grooved upper surface of the inguinal ligament in the whole extent(b) Abdominal surface of the lacunar ligament at the medial end

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Contents of inguinal canalSpermatic cord & its contents in male

Round ligament in female

Genital branch of genitofemoral nerve

Ilioinguinal

nerve-Enter

the canal through the posterior wall

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Spermatic Cord

It is a collection of structures that pass through the inguinal canal to and from the testis

It is covered with three concentric layers of fascia derived from the layers of anterior abdominal wall

It begins at the deep inguinal ring lateral to the inferior epigastric artery and ends at the testis

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Structures of Spermatic Cord

Vas deferens

Testicular artery and vein

Testicular lymph vessels

Autonomic nerves

Processus vaginalis

Cremastric artery

Artery of the vas deference

Genital branch of genitofemoral nerve

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Covering of the Spermatic Cord

External Spermatic fascia

: Is derived from the external oblique aponeurosis and attached to the margins of the superficial inguinal ring

Cremasteric Fascia

: Is derived from the internal oblique muscle

Internal Spermatic Fascia

: Is derived from the fascia transversalis and attached to the margins of deep inguinal ring

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Vas Deferens

It is a cord like structure

Can be palpated between finger and thumb in the upper part of the scrotum

It is a thick walled muscular duct that transport spermatozoa from the epididymis to the prostatic urethra

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Testicular Artery

It is a branch of abdominal aorta at level of L2

It is long and slender

Descends on the posterior abdominal wall

It traverses the inguinal canal and supplies the testis and the epididymis

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Testicular Veins

These are the extensive venous plexus, the pampiniform plexus

Leaves the posterior border of the testis

As the plexus ascends, it becomes reduced in size so that at about the level of deep inguinal ring, a single testicular vein is formed

Drains into left renal vein on left side and inferior vena cava on right side

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Testicular artery & vein

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Autonomic nerve & Genitofemoral nerve

Autonomic nerves

Sympathetic fibers run with testicular artery from renal or aortic sympathetic plexuses

Afferent sensory nerve

Genital branch of the genitofemoral nerve

-

Its root L1& L2

- Supply the cremastric muscle

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Testicular lymphatic vessels

Ascend through the inguinal canal

Passes up over the post. Abdominal wall

Reach the lumbar (Para-aortic) lymph nodes on each side of the aorta at level L1

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Processus vaginalis

An out pouching of peritoneum that in the fetus is responsible for the formation of the inguinal canal.

The remains of the processus vaginalis causes the indirect hernia.

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MECHANISMS TO MAINTAIN THE INTEGRITY OFTHE INGUINAL CANAL

1)

Flap-valve Mechanism

2) Guarding of the inguinal rings .

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3)Shutter Mechanism

The internal oblique surrounds the canal in front, above, and behind like a flexible mobile arch and thus forming its anterior wall, roof, and posterior wall.

Consequently

, when it contracts, the roof is pulled and approximated on the floor like a shutter

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Slit-valve MechanismThe contraction of external oblique muscle approximates

the

two crura medial and lateral of superficial inguinal ring

like

a slit valve. The intercrural fibres also help in this act.

Ball-valve Mechanism

Contraction of cremaster muscle pulls the testis up and the

superficial

inguinal ring is plugged by the spermatic cord.

N.B. In addition to the above mechanisms, the interfoveolarligament also helps to maintain the integrity of the inguinalcanal by strengthening fascia transversalis laterally. The muscle fibres arch down from the lower border of transversus abdominis

to the superior ramus of pubis and constitute

the interfoveolar

ligament—the functional medial edge of

the deep

inguinal ring

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INGUINAL TRIANGLE (HESSELBACH’S TRIANGLE)

The inguinal triangle is situated deep to the posterior

wall of

the inguinal canal; hence, it is seen on the inner aspect

of the

lower part of the anterior abdominal wall.

BOUNDARIES

Medial:

Lower 5 cm of the lateral border of the

rectus abdominis muscle.Lateral: Inferior epigastric artery.Inferior: Medial half of the inguinal ligament.

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The floor of the triangle is covered by the

peritoneum,

extraperitoneal

tissue, and fascia transversalis.

The

medial umbilical ligament (obliterated

umbilical artery

) crosses the triangle and divides it into medial

and lateral

parts. The medial part of the floor of the triangle is strengthened by the conjoint tendon.The lateral part of the floor of the triangle is weak, hence direct inguinal hernia usually occurs through this part

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APPLIED IMPORTANCE OF INGUINAL CANAL

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Hernia

A

n abnormal protrusion of a viscous or a part of viscous through an opening natural or artificial with a sac covering it.

P

arts:

sac

contents of the sac covering of the sac

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CLASSIFICATION

1)CONTENTS:

Omentocele_omentum

Enterocele_intestine

Littre’s hernia_meckels’s diverticulum.

2

)CLINICAL:

Reducible hernia

Irreducible hernia

Obstructed herniaStrangulated hernia

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Inguinal hernias

There

are two types of inguinal

hernias

direct

and indirect.

Indirect

inguinal hernia

:

Hernial sac enters the inguinal canal through the deep inguinal ringLateral to the inferior

epigastric artery .

Common in

children and young adults

.

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Types

1)Congenital

indirect inguinal hernia:

Occurs due to patent processus vaginalis

2)

Acquired indirect inguinal hernia

:

It occurs due to increased intra-abdominal pressure as during weight lifting.

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Coverings of indirect inguinal hernia

•Extraperitoneal

tissue

• Internal spermatic fascia

• Cremasteric fascia

• External spermatic fascia

•

Skin

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Direct inguinal

hernia

.

The

hernial sac enters the inguinal

canal directly

by pushing the posterior wall of the

inguinal canal.

Medial

to inferior epigastric artery through the Hesselbach’s triangle. The direct inguinal hernias are common in elderly due to weak abdominal muscles. TYPESlateral direct inguinal hernia

medial

direct

inguinal hernia

.

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Coverings of direct inguinal hernia

• Extraperitoneal tissue

• Fascia transversalis

• Conjoint tendon (in medial direct hernia)

• Cremaster fascia (in lateral direct hernia)

• External spermatic fascia

• Skin

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Cysts and Hernias of Canal of Nuck

If

the processus vaginalis persists in females, it forms

a small

peritoneal pouch, the

canal of Nuck,

in the inguinal

canal which extend

to the labium majus

. In female infants, such remnants can enlarge and form cysts in the inguinal canal. The cysts may produce a bulge in the anterior part of the labium majus and have the potential to develop into an indirect inguinal hernia

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Torsion of Spermatic Cord

It

is a surgical

emergency.

The torsion obstructs the

venous drainage, with resultant edema and

hemorrhage , and

subsequent arterial obstruction

.

The twisting usually occurs just above the upper pole of the testis To prevent recurrence or occurrence on the contralateral side, which is likely, both testes are surgically fixed to the scrotal septum.

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Hydrocele of Spermatic Cord

A

hydrocele

is the presence of excess

fluid

in a

persistent processus

vaginalis

.

May be associated with an indirect inguinal hernia. A hydrocele of the spermatic cord is confined to the spermatic cord and distends the persistent part of the stalk of the processus

vaginalis.

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Spermatocele

A

spermatocele

is a retention cyst (collection of

fluid)in

the

epididymis,

usually near its head.

Spermatoceles contain a milky

fluid and are generally asymptomatic.

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Thank

you