Surgical and applied anatomy of the inguinal canal

1. Surgical Anatomy of the inguinal
canal
Presenter: DR PASHI V.M
MODERATOR: DR. TEMBO
16/01/2015
THE UNIVERSITY TEACHING HOSPITAL
LUSAKA , ZAMBIA

2. Surface anatomy of anterior abdomen

3. Anterior abdominal wall
• Has 8 layers before you enter the peritoneal cavity
• Skin
• Subcutaneous tissue- Camper’s fascia
• - Scarper’s Fascia
• External oblique
• Internal Oblique
• Transversus Abdominis
• Transversalis fascia
• Extraperitoneal Fat
• Parietal Peritonium

4. Anterior abdominal muscles

6. Inguinal canal
 It is an oblique passage through the lower part of the anterior
abdominal wall
 Present in both sexes
 It allows structures to pass to and from the testis to the
abdomen in males
 In females it permits the passage of the round ligament of the
uterus from the uterus to the labium majus
 Transmits ilioinguinal nerve in both sexes

7. Inguinal canal
• It is about 1 ½ inches or 4cm long in the adults
• Extends from the deep inguinal ring downward
and medially to the superficial inguinal ring
• Lies parallel to and immediately above the
inguinal ligament
• In the newborn child, the deep ring lies almost
directly posterior to the superficial ring

8. Inguinal canal in females

9. Inguinal canal in males

10. Development of the inguinal canal
• The canals form the pathways for the testes to
descend through the abdominal wall into the
scrotum.
• AS THE MESONEPHROS degenerates, the
gubernaculum (a ligament) descends on each
side from the lower poles of the gonads,
• THE PROCESSUS VAGINALIS (peritoneal sac)
develops later, on each side, ventral to the
gubernaculum, and herniates through the
lower abdominal wall along the pouch formed
by the gubernaculum

11. Development
• Each processus carries extensions of layers of
the abdominal wall before it, and together
they form the walls of the inguinal canal. In
the male, they also form the coverings for the
testes and the spermatic cord
• The opening produced in the transversalis
fascia by the processus is the deep inguinal
ring and that in the external oblique
aponeurosis becomes the external or
superficial inguinal ring. Between the rings is
the inguinal canal.

12. descent of gonads

13. Anomalies of inguinal c development
• ANOMALIES OF TESTICULAR MIGRATION: They
range from simple ectopy, where the testis may
be inguinoscrotal or inguinal, to cryptorchism,
where the testis is pelvic, iliac, or even lumbar
• ANOMALIES OF VAGINAL PROCESS CLOSURE :
They may be (not always) associated with
problems of testicular migration
• Cysts of the spermatic cord are signs of
incomplete closure
• A complete failure of closure may result in
congenital oblique external hernia or
communicating hydrocele

14. Structures of the inguinal canal
• Deep inguinal ring half way between a line drawn
from pubic symphisis to anterior superior iliac
spine.
Relations
• Anterior: Skin, fascia, Aponeurosis external
Oblique + Internal Oblique
• Above: Arching Fibres of Internal Oblique &
Transversus Abdominis
• Posteriorly: Transversalis Fascia & Conjoint
Tendon
• Below: Inguinal Ligament recurved lower edge of
the external oblique aponeurosis

15. j

16. Anterior Wall of Inguinal Canal
• Is formed along its entire length by
aponeurosis of the external oblique muscle
• It is reinforced in its lateral third by the origin
of the internal oblique from the inguinal
ligament
• This wall is strongest where it lies opposite the
weakest part of posterior wall, that is deep
inguinal ring

17. Posterior Wall of Inguinal Canal
• Is formed along its entire length by the fascia
transversalis
• It is reinforced in its medial third by conjoint
tendon, the common tendon of insertion of
internal oblique and transversus, attached to the
pubic crest and pectineal line
• This wall is strongest where it lies opposite the
weakest part of the anterior wall, that is
superficial inguinal ring

18. Inferior Wall of Inguinal Canal
• Is formed by the rolled-under inferior edge of
the aponeurosis of the external oblique
muscle called inguinal ligament and at its
medial end, the lacunar ligament

19. Superior Wall of Inguinal Canal
• Is formed by the arching lowest fibers of the
internal oblique and transversus abdominis
muscles

21. Functions of Inguinal Canal
• It allows structures of spermatic cord to pass
to and from the testis to the abdomen in male
• Permits the passage of round ligament of
uterus from the uterus to the labium majus in
female

22. Mechanics of Inguinal Canal
• The presence of inguinal canal in the lower
part of the anterior abdominal wall in both
sexes constitutes a potential weakness
• Except in the newborn infant, the canal is an
oblique passage with the weakest areas, that
are superficial and deep inguinal rings

23. Mechanics of Inguinal Canal
• When great straining efforts may be
necessary, as in defecation and parturition,
the person naturally tends to assume the
squatting position
• The hip joints are flexed and the anterior
surfaces of the thighs are brought up against
the anterior abdominal wall
• By this means the lower part of the anterior
abdominal wall is protected by the thighs

24. 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

25. 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

27. 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 urethra

28. Testicular Artery
• It is a branch of abdominal aorta
• It is long and slender
• Descends on the posterior abdominal wall
• It traverses the inguinal canal and supplies the
testis and the epididymis

29. 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

30. Covering of the Spermatic Cord
• The covering of the spermatic cord are three
concentric layers of fascia derived from the
layers of the anterior abdominal wall
• Each covering is acquired as the processus
vaginalis descends into the scrotum through
the layers of the abdominal wall

32. 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

33. Inguinal Hernia
• A hernia is the protrusion of part of the
abdominal contents beyond the normal
confines of the abdominal wall
• Consists of three parts: the sac, contents of
the sac, covering of the sac
• Hernial coverings are formed from the layers
of the abdominal wall through which the
hernial sac passes

34. Indirect Inguinal Hernia
• If the processus vaginalis has undergone no
obliteration, the hernia is complete and extends
through the superficial inguinal ring down into the
scrotum or labium majus
• Under these circumstances the neck of the hernial
sac lies at the deep inguinal ring
• It is 20 times more common in young males than
females
• Is more common on the right side

35. Direct Inguinal Hernia
• It composes about 15% of all inguinal hernias
• Common in old men with weak abdominal muscles
and rare in women
• Hernial sac bulges forward through the posterior wall
of the inguinal canal medial to the inferior epigastric
artery
• The neck of the hernial sac is wide
• Hasselbachs triangle.. Medially the rectus sheath,
laterally the inferior epigastric vessels, inferiorly , the
inguinal ligament…sight of direct inguinal hernias

36. Hasselbachs triangle

38. Related hernias
• Femoral hernias : Protrusion of the parietal
peritoneum down the femoral canal
• More common in women than men
• Neck of the sac is narrow lies below and
lateral to pubic tubercle
• Femoral canal where the neck lies is related
anteriorly to the inguinal ligament, posteriorly
to pubs and pectineal line. Laterally to femoral
vein and medially to the lacuna ligament.

40. Herniorraphy
SUTURE REPAIR
BASSINI REPAIR
SHOULDICE REPAIR
PLICATION - DARN REPAIR
FEMORAL HERNIA REPAIR
FEMORAL APPROACH
INGUINAL APPROACH
EXTRAPERITONEAL APPROACH
MESH REPAIR
OPEN REPAIR
LICHTENSTEIN REPAIR (OPEN ANTERIOR)
RIVES and KUGEL PATCH REPAIRS (OPEN POSTERIOR)
PERFIX PLUG REPAIR
PROLENE HERNIA SYSTEM REPAIR
STOPPA REPAIR
LAPAROSCOPIC REPAIR

41. Name of Repair Type of Repair Recurrence Rates
Modified Bassini Conjoined tendon to inguinal ligament 5 - 15%
Modified McVay Conjoined tendon to Cooper’s ligament 5 - 15%
Shouldice / Modified Shouldice Three or four layer tissue repair <1 - 7%
Plication - Darn Repair ‘Tension-free’ suture repair 2 – 9 %
Lichtenstein Onlay mesh <1 - 5%
Kugel Preperitoneal mesh 4%
PerFix plug Plug and patch 4%
Prolene Hernia System Preperitoneal and onlay mesh <1 – 3%
Stoppa Large preperitoneal mesh <1%

42. Herniorraphy
• Modified Bassinis Repair- Developed in 1880
involves reinforcing or repair of posterior wall by
suturing the conjoint tendon to inguinal ligament.
• Commonly used at UTH.
• Has failure rate of about 0.2 -8.5% failure
(recurrence) rate.
• Technique is most important determinant!!!
• Use Non absorbable sutures.
• Shouldice Repair: also called Canadian repair.
Involves dividing the transversalis fascia and
repairing the posterior wall in four layers.
Associated with 0.1- 6.1% failure rate. Dependent
on surgeons technique

43. References
• Ellis H. Clinical Anatomy
• www.vesalius.com
• Raftery, A.T(2008), Applied Basic Science for
Basic Surgical Training, Elsevier, USA.
• Netter, F, Interactive Atlas of Human Anatomy