ANATOMY OF ANTERIOR ABDOMINAL WALL, useful for undergraduates

1. ANATOMY OF ANTERIOR
ABDOMINAL WALL
Presented By, Dr. Prajwal R K, Dept. of General surgery
KIMS, Bengaluru

2. INTRODUCTION
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▰ The anterior abdominal wall constitutes a
hexagonal area
▻ Superiorly – by the costal margins and
xiphoid process,
▻ Laterally – by the midaxillary line, and
▻ Inferiorly – by the iliac crests, pubis and
pubic symphysis.
▰ This includes Inguinal Region also…

3. SURFACE TOPOGRAPHY
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▰ four-quadrant pattern
▰ nine-region
organizational
description

4. INTRODUCTION
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Layers of the abdominal wall
▰ Skin
▰ Soft Tissue
▰ Muscle and connective
tissue

5. SOFT TISSUE
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Superficial fascia
Between dermis and the muscles
▰ superficial fatty layer (Camper’s
fascia)
▰ deep membranous layer
(Scarpa’s fascia).
▰ Deep adipose layer

6. SUPERFICIAL LAYER (Camper’s fascia)
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▰ It’s continuous with superficial
fat over the rest of the body.
▰ In the scrotum is modified as a
thin smooth muscular layer
called dartos muscle

7. DEEP MEMBRANOUS LAYER (Scarpa’s fascia)
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▰ Measured histologically, it is
between 0.5 and 1 mm thick.
▰ Superiorly, it is continuous with
the superficial fascia over the
remainder of the trunk
▰ In the midline, it is adherent to
the linea alba and pubic
symphysis

8. DEEP MEMBRANOUS LAYER (Scarpa’s fascia)
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▰ Inferiorly, it fuses with the iliac crest
▰ fuses with the fascia lata at the
inguinal flexure
▰ it extends on to the scrotum,
▰ it becomes continuous with the
membranous layer of superficial
fascia of the perineum (Colles’
fascia)

9. DEEP MEMBRANOUS LAYER (Scarpa’s fascia)
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▰ In the male, it extends on to the
dorsum of the penis to form the
fundiform ligament of penis

10. Schematic representation of the layers
of the anterolateral abdominal wall.
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1, skin;
2, fatty layer of superficial fascia (Camper fascia);
3, neurovascular supply of superficial fascia;
4, membranous layer of superficial fascia (Scarpa fascia);
5, space with areolar tissue;
6, deep fascia (outer investing fascia of external oblique muscle);
7, external oblique muscle;
8, inner investing fascia of external oblique muscle and outer
investing fascia of internal oblique muscle (they fuse; here
presented separately for didactic reasons);
9, internal oblique muscle;
10, inner investing fascia of internal oblique muscle and outer
investing fascia of tranasversus abdominis muscle (they fuse; here
presented separately);
11, neurovascular bundle of abdominal muscles (between internal
oblique and transversus abdominis muscles);
12, transversus abdominis muscle;
13, transversalis fascia (the inner investing fascia of the
transversus muscle);
14, parietal compartment of preperitoneal space;
15, membranous layer of preperitoneal tissue;
16, preperitoneal fat in the visceral compartment of preperitoneal
tissue;
17, peritonmeum.

11. MUSCLES of ANTERIOR ABDOMINAL WALL
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5 Muscles
▰ 3 flat muscles
▻ External Oblique
▻ Internal Oblique
▻ Transersus abdominis
▰ 2 vertical muscles
▻ Rectus abdominis
▻ Pyramidalis

12. EXTERNAL OBLIQUE
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13. INTERNAL OBLIQUE
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14. TRANSVERSUS ABDOMINIS
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15. RECTUS ABDOMINIS
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16. PYRAMIDALIS
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17. TRANSVERSALIS FASCIA
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▰ thin layer of connective tissue
lying between the deep surface
of transversus abdominis and
the extraperitoneal fat
▰ Posteriorly, it fuses with the
thoracolumbar fascia
▰ transversalis fascia is prolonged
as the internal spermatic fascia

18. PERITONEUM
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▰ The peritoneum lining the walls
is the parietal peritoneum;
▰ The peritoneum covering the
viscera is the visceral
peritoneum

19. Rectus Sheath
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▰ Rectus abdominis on each side is
enclosed by a fibrous sheath
▰ formed from the aponeuroses of all
three lateral abdominal muscles
▰ anterior portion fuses with
periosteum and ligaments at sites
of the muscle’s attachments

20. Rectus Sheath
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▰ Each aponeurosis is
bilaminar
▰ anterior leaves run
obliquely upwards
▰ Posterior leaves run
obliquely downwards

21. Rectus Muscle and Sheath
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22. Linea Alba (the white line)
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▰ The linea alba is a tendinous raphe
extending from the xiphoid process to
the pubic symphysis and pubic crest
▰ lies between the two recti
▰ 15–22 mm along its course, widest at
or just above the umbilicus and
narrowing at superior and inferior
extremes

23. Linea Alba (the white line)
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▰ completely avascular – preferred location for incision
and intra-abdominal access
▰ lack of muscular coverage leads to weakness and
the formation of the majority of de novo ventral
hernias
▰ Ultimately, the goal of abdominal wall reconstruction
remains to restore linea alba by bringing the paired
rectus muscles back to the midline

24. ARCUATE LINE
OF DOUGLAS
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▰ linea semicircularis Located one-third
of the distance between the umbilicus
and the pubis
▰ the arcuate line represents the lower
limit of the posterior rectus sheath
▰ Below the arcuate line only the
transversalis fascia remains between
the rectus abdominis and peritoneum

25. ARCUATE LINE
OF DOUGLAS
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▰ Here, both Spigelian and arcuate line
hernias may occur
▰ arcuate line also serves as a
landmark where the inferior epigastric
vessels perforate the rectus
abdominis
▰ The arcuate line must be incised at its
lateral-most point in order to enter the
space of Retzius and Bogros from
within the rectus sheath

26. Umbilical Region
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27. Umbilical Region
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▰ It consists of skin, a fibrous
layer (representing the area
of fusion between the round
ligament of the liver, the
median umbilical ligament,
and two medial umbilical
ligaments), the transversalis
fascia, the umbilical fascia
surrounding the urachal
remnant, and peritoneum

28. Umbilical Region
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▰ Variations in umbilical ring
(UR) and umbilical fascia
seen from posterior
(peritoneal) surface of body
wall

29. SEMILUNAR LINE (LINEA SPIGELI)
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▰ Extends from the tip of the
ninth costal cartilage to the
pubic tubercle.
▰ site of transition from the
aponeurotic part to the
muscular part of the transverse
abdominal muscle

30. SEMILUNAR LINE (LINEA SPIGELI)
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31. SEMILUNAR LINE (LINEA SPIGELI)
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▰ The spigelian aponeurosis is the aponeurosis of
the transverse abdominal muscle
▰ limited by the linea semilunaris laterally
▰ lateral edge of the rectus muscle medially.
▰ weakest point is at the intersection between the
semilunar and semicircular line

32. Comparison of upper and lower three-fourths of
anterior abdominal wall
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Upper Midline Lower Midline
Linea alba well developed Linea alba poorly
developed
Right and left recti well
separated
Right and left recti close
together
Anterior and posterior
layers of sheath present
Only anterior layer of
sheath present
Aponeurosis of external
oblique weak or absent
Aponeurosis of external
oblique strong and well
developed

33. Vessels of anterior abdominal wall
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▰ EOP- Ext Oblique Perforators
▰ SCI- Superficial Circumflex Iliac
▰ SE- Superior Epigastric
▰ DCI- Deep Circumflex Iliac
▰ IE- Deep , inferior Epigastric
Artery
▰ SIEA- Superficial inferior
Epigastric artery

34. Blood
Supply
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35. Blood Supply
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36. Vascular supply to the abdominal wall with delineated
Huger Zones I–III
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▰ Zone I – SEAs and DIEAs – rectus
abdominis and overlying subcutaneous
tissue and skin
▰ Zone II – SIEA and superficial external
pudendal arteries – superficial fascia and
skin
▰ The DIEAs and deep circumflex iliac
arteries supply the musculature in this
lower area.
▰ Zone III – lumbar and intercostal arteries

37. Lymphatics
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▰ Superficial lymphatics
above the umbilicus
pass in a superior
direction to the axillary
nodes,
▰ below the umbilicus
passes in an inferior
direction to the
superficial inguinal
nodes.

38. Nerve Supply
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▰ The skin and muscles of the
anterolateral abdominal wall are
supplied by T7 to T12 and L1
spinal nerves

39. Nerve Supply
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▰ The lateral neurovascular
structures travel in the TAP
between the TAM and IOM
▰ Delivery of local anesthetic
into this plane provides
blockade to the sensory
nerves
▰ TAP block – Improvements in
post-operative pain scores,
opioid use, and hospital stay

40. EXTRAPERITONEAL SPACES
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Space of Retzius Space of Bogros

41. Landmarks
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▰ Inguinal Landmarks in
Hernia Repair:
▰ Warning Triangles and
Corona Mortis

42. Incisions on Abdominal Wall
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▰ “ Pray before surgery, but remember: God will not alter a faulty
incision”
▻ • Keeney’s Dictum
▻ Maingot’s 3 requirements
▻ • Accesibility
▻ • Extensibility
▻ • Security

43. Varieties of Abdominal incisions
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44. Midline Incisions
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45. Paramedian Incision
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46. Pararectus Incision (Kammerer-Battle)
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47. Midrectus (transrectus )Incisions
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48. Pfannelstiel Incision
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49. Ventral hernias
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▰ Umbilical–paraumbilical
▰ Epigastric
▰ Incisional
▰ Parastomal
▰ Spigelian
▰ Lumbar
▰ Traumatic

50. Lumbar
hernias
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51. REFERENCES
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52. EVERYTHING WE HEAR IS AN OPINION, NOT A FACT. EVERYTHING WE SEE IS A
PERSPECTIVE, NOT THE TRUTH!
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KIMS
THANKS!
Any questions?
You can find me at
prajjurk@gmail.com