Surgical understanding of hernia repairs with eTEP, component fixation both anterior and posterior require a detailed knowledge of anatomy

1. Anatomy of Anterior
Abdominal Wall
Dr Pravin John MS, FALS, FIBC
Dr John Thanakumar MS, MNAMS, FRCS, FRCS,FALS,DipMIS
Laparoscopic Surgery,
ANURAG HOSPITAL
Coimbatore

2. Boundaries of abdominal wall
Physiology
Covers viscera
Strengthens the core
Helps breathing
Helps defecation
Corset
Aids childbirth
Aids forward, lateral flexion of abdomen
Boundaries of abdominal wall
Above: Xiphoid process
Costal margins of ribs
Below: Ant Ilium, pubic bone
Front: Abdominal wall
Behind: 5 vertebrae

3. Structures
Anterior abdominal wall muscles
Their aponeurosis
Nerves
Fascias
SC fat
Skin

4. Cutaneous Nerves
Sensory Innervation
Segmentally by anterior rami of T7-L1.
Above umbilicus T7-9
At umbilicus T 10
Below umbilicus T11,12 & L1 (I.Hypo,I.Ing)

5. Fascia
Superficial fascia (SF)
Above umbilicus- Single SF
Below umbilicus, 2 layers
Ext, fatty Camper’s fascia
Int, fibrous Scarpa’s fascia

6. Muscles of AAW
Laterally 3 muscles oblique to each other, aponeurotic end
Ext Oblique - ‘hands in the pocket’
Int Oblique - ‘opposite direction’
Transversus abdominis
Anterior - Left and Right Rectus muscles

7. Left, Right Recti
Origin
Xiphoid process,
Costal margins of 5-7 ribs
Insertion
Pubic Symphysis
Action
Tenses abdominal wall
Flexion
Defecation, Urination
Parturation
Stabilizes pelvis
Blood Supply
SEA, IEA & veins
Lower 6 segmental IC Vessels
Nerve Supply
Ant Rami of T7-T12
The pyramidalis muscle is a small triangular-shaped muscle
from the pubis ventral
to the insertion of the rectus abdominis muscle
within the rectus sheath to the linea albas
subcostal nerve or the twelfth intercostal nerve.

8. Vascular supply of abdominal wall with Huger
Zones I, II, III

9. Rectus sheath
Rectus sheath covers RM anteriorly and posteriorly
Posterior sheath ends inferiorly between Umb and pubis
Ant. & Post. layers of sheath by division of Int Obl muscle above semicircular line
Ext Obl apneurosis joins anterior rectus sheath
TA aponeurosis joins posterior sheath above the SC line
Below the SC line, muscle is covered with transversals fascia

10. Linea Alba
Avascular midline plane
Decussing fibres of Ext, Int.Oblique & TA aponeurosis
Strong avascular layer of abdominal wall in surgical closure

11. External Oblique Muscle
Origin
Lower 8 ribs
Insertion
Into aponeurosis,
Lower part folds back as inguinal ligament
Into pubic tubercle
Anterior half of iliac crest
Lower medially forms superficial inguinal ring
Action
Raises IAP ( Valsalva)
Flexes and rotates the vertebral column
Nerve Supply
Ant rami of lower 6 nerves T7 to T12

12. Int Oblique Muscle
Origin
Deep fascia to lateral 1/2 inguinal ligament
Anterior 2/3 of iliac crest
Lumbo-dorsal fascia
Insertion
As aponeurosis into rectus sheath
Linea alba
Pubic crest ( via conjoint tendon)
Lower 10-12 ribs cartilages above
Action
Accessory Muscle for respiration
Torsional movements of the trunk
Nerve Supply
Lower six thoracic dorsal nerves
Ist L nerves- Ilio hypogastric and Ilio inguinal N
Special Note
Aponeurosis in middle
Above arcuate line
Inserts into ant and post rectus sheath
Below arcuate line
Inserts into ant rectus sheath

13. Origin
Most inner layer muscle
From lateral Iliopubic tract
Iliac crest
Lumbo Dorsal Fascia
Last 6 ribs
Insertion
Forms a large aponeurosis in midline
Above arcuate line, into ant/ post rectus sheath
Below arcuate line into ant rectus sheath
Lower margin is the upper part of internal ring
Joins internal oblique to form conjoint tendon
Action
Compresses viscera of thorax, abdomen, pelvis
Parturation, Corset muscle
Stabilizes spine and pelvis in wt lifting exercises
Nerve supply
Lowest 6 IC nerve anterior rami T7 - T12
Ilio hypogastric, Ilio inguinal N - L1
Transversus Abdominis
TA muscle is more on top
TA aponeurosis is more below

14. Innominate fascia covers the external oblique muscle
Transversalis fascia forms the investing layer of abdominal cavity
Preperitoneal fat separates the TF from peritoneum
Fascia of importance
Space of Retzius
Space of Bogros - Medial with Fem. vessels, Lateral with Fem. N

15. Nerves of AAW
T6-T12 IC Nerves travel between
TA and Internal Obleque,
Pierce Post Rectus sheath Except L1
Perforation NV bundles perforated
the post lamella of the Rectus sheath
from laterally to supply the Rectus

16. Surgical Anatomy
Preperitoneal Space for TEP
Mesh Placement for Ventral Hernias

17. Surgical Anatomy for recurrent ventral hernias
Anterior Component Separation
(Open/Lap) via lateral to aponeurosis
Posterior Component Separation(Open/Lap)
Post Rectus Sheath divided,
Medial to Perforation branches
To access and divide the TA fibres
END