28.Stucture of the abdominal wall. Hernias.Birth defects of abdominal wall

Question 1

Hernia Definition

Answer 1

A hernia is a protrusion of a viscus or part of a viscus through an abnormal opening in the walls of its containing cavity.

A hernia occurs when an organ pushes through an opening in the muscle or tissue that holds it in place.

Question 2

Hernia - most common

Answer 2

The external abdominal hernia is the most common form

Question 3

Hernia - cases

Answer 3

The most frequent varieties being the
inguinal
femoral
umbilical, accounting for 75% of cases

• The rarer forms constitute 1.5%, excluding incisional hernias.

Question 4

Hernia Etiology

Answer 4

• Coughing
• Straining
• Obesity
• Intra-abdominal malignancy
  Urinary causes

Old age—BPH, carcinoma prostate.

Young age—stricture urethra.

Very young age—phimosis, meatal stenosis.

Obesity.

Pregnancy and pelvic anatomy (especially in femoral hernia in females).

Smoking

Ascites.

Appendecectomy through McBurney’s incision may injure the ilioinguinal nerve
causing right sided direct inguinal hernia.

Question 5

Parts of hernia

Answer 5

Hernia comprised of:

Covering

Sac

Content

Question 6

Hernia - sac

Answer 6

Sac is a diverticulum of peritoneum with mouth, neck, body and fundus.

Neck is narrow in indirect sac but wide in direct sac.

Body of the sac is thin in infants, children and in indirect sac, but is thick in direct and long-standing hernia.

Question 7

Hernia - covering

Answer 7

Coverings of the sac are the layers of the abdominal wall through which the sac
passes.

Question 8

Hernia - contents of sac

Answer 8

Omentum—Omentocele. Difficult to reduce the sac later, initially it can be
reduced easily.

Intestine—Enterocele—commonly small bowel, but sometimes even large
bowel. Difficult to reduce the sac initially.

Richter’s hernia: A portion of circumference of bowel is the content.
Urinary bladder may be the content or part of the posterior wall of the
sac—cystocele.

Ovary, often with fallopian tube.

Meckel’s diverticulum—Littre’s hernia.

Appendix in inguinal hernial sac which is often incarcerated—

Fluid: Fluid is secreted from congested bowel or omentum. It may be an
infected fluid or ascitic fluid or blood from the strangulated sac.

Question 9

Hernia - Classification

Answer 9

Classification 1 : clinical

Classification 2 congenital or acquired

Classification 3 : According to the Contents

Classification : Based on Sites

Question 10

Hernia - Classification 1

Answer 10

Reducible Hernia

Irreducible Hernia

Obstructed Hernia

Inflamed Hernia

Strangulated Hernia

Question 11

Hernia - Classification 1 - Reducible Hernia

Answer 11

Hernia gets reduced on its own or by the patient or by the surgeon.

Intestine reduces with gurgling and it is difficult to reduce the first portion.

Omentum is doughy, and it is difficult to reduce the last portion. Expansile impulse on coughing
present.

Question 12

Hernia - Classification 1 - Irreducible Hernia

Answer 12

Here contents cannot be returned to the abdomen due to narrow neck, adhesions, overcrowding. Irreducibility predisposes to strangulation.

Question 13

Hernia - Classification 1 -Obstructed Hernia

Answer 13

It is an irreducible hernia with obstruction, but blood supply to the bowel is not interfered.

It eventually leads to strangulation

Question 14

Hernia - Classification 1 -Inflamed Hernia:

Answer 14

It is due to inflammation of the contents of the sac, e.g. appendicitis, salpingitis.

Here hernia is tender but not tense; overlying skin is red and oedematous.

Question 15

Hernia - Classification 1 -Strangulated Hernia

Answer 15

It is an irreducible hernia with obstruction to blood flow.

The swelling is tense, tender, with no impulse on coughing and with features of intestinal obstruction.

Question 16

Hernia - Classification 2 - Congenital

Answer 16

Common: It occurs in a preformed sac/defect.

Clinically may present at
a later period due to any of the precipitating causes like in indirect inguinal hernia.

Question 17

Hernia - Classification 2 -Acquired

Answer 17

It is secondary to any causes which raise the intra-abdominal pressure
leading into weakening of the area like in direct inguinal hernia.

Question 18

Hernia - Classification 3

Answer 18

Omentocele—omentum.
Enterocele—intestine.

Cystocele—urinary bladder.

Littre’s hernia—Meckel’s diverticulum.

Note: Littre described Meckel’s diverticulum in a hernial sac 81 years before
Meckel was born.

Maydl’s hernia.

Sliding hernia.

Richter’s hernia—part of the bowel wall.

Question 19

Hernia - Classification 4

Answer 19

Inguinal hernia—occurring in inguinal canal.

Femoral hernia—occurring in femoral canal.

Obturator hernia.

Diaphragmatic hernia.

Lumbar hernia.

Spigelian hernia.

Umbilical hernia.

Epigastric hernia.

Question 20

Hernia - Clinical presentation

Answer 20

Sudden pain, generalised abdominal pain (colicky in character),

Nausea + vomiting,

Increase in hernia size,

On examination hernia is tense, extremely tender + irreducible, no expansible cough impulse

Spontaneous cessation of pain must be viewed with caution – could be sign of perforation

If strangulated urgent surgery

Question 21

Hernia - Treatment

Answer 21

• Simple suture closure, mesh repair where :
  1. Midline scar is opened – adhesions are lysed + the ileostomy taken down
  2. Mobilised segment of bowel removed
  3. End to end anastomoses to connect bowel with ileocecal stump.
  4. Large piece of mesh is locked down to the fascia to reinforce the ventral aspect

Question 22

Birth defects of abdominal wall

Answer 22

Gastroschisis (belly cleft)

Omphalomesenteric cyst due to Failure of vitelline duct regression

Meckel’s diverticulum If the vitelline remnant persists at the ileal border

Urinary fistula or cyst (patent urachus) if there is Failure of the urachus to close

Question 23

Abdominal wall - flat muscles

Answer 23

external oblique muscle
internal oblique muscle
transversus abdominis muscle

Question 24

Abdominal wall - verticle muscles

Answer 24

Rectus Abdominis muscle

Pyramidalis muscle

Question 25

Rectus Abdominis is split into two by

Answer 25

linea alba.

Question 26

Rectus sheet formed by

Answer 26

aponeurosis.

Question 27

Abdominal wall - anterior wall muscles

Answer 27

external oblique muscle

half of internal oblique muscle

Question 28

Abdominal wall - posterior wall muscles

Answer 28

half of internal oblique muscle
+
transversus fascia.