Part two - hernia

Question 1

Principles of incisional hernia repair

Answer 1

1. Prevention of visceral eventration
2. Incorporation of the remaining abdominal wall in the repair
3. Provision of dynamic muscular support
4. Restoration of abdominal wall continuity in a tension-free manner

Question 2

Define hernia

Answer 2

An abnormal protrusion of tissue or viscus through a defect either in the containing wall or within the cavity in which the tissue/viscus is contained.

In abdominal hernias, the wall refers to the anterior and posterior layers of the abdomen, the diaphragm and the walls of the pelvis.

Question 3

Define an external hernia

Answer 3

An abnormal protrusion of intra-abdominal tissue through a fascial defect in the abdominal wall.

Question 4

Define an internal hernia

Answer 4

When the intestines passes between a constricting band or through a peritoneal window within the abdominal cavity or in the diaphragm.

Question 5

Richter’s hernia

Answer 5

When only part of the bowel wall circumference (anti mesenteric border) becomes incarcerated

Question 6

Littre’s hernia

Answer 6

When a Meckel’s diverticulum lies within the hernia sac.

Most commonly an inguinal or femoral hernia.

Question 7

Maydl’s hernia

Answer 7

Two adjacent bowel loops are within the sac and the intervening portion becomes strangulated

Question 8

Herniotomy

Answer 8

Excision of the hernia sac

Question 9

Herniorraphy

Answer 9

Repair and close the defect by approximation of adjacent tissues to restore normal anatomy.

Examples are Bassini and Shouldice repairs

Question 10

Hernioplasty

Answer 10

Repair and closure of the defect by insertion of additional material.

Example is Lichtenstein technique

Question 11

Amyand’s hernia

Answer 11

An inguinal hernia sac containing an appendix

Question 12

Bassini repair

Answer 12

Essentially suturing conjoint tendon to inguinal ligament

• Division of the cremaster lengthwise
• Resect indirect sac with high ligation
• Inspect for a direct hernia
• Transversalis fascia is divided along its full length
• Inspect for a femoral hernia
• Prepares the flaps for repair - triple layer of tranversalis fascia, transverses abdominis and internal oblique muscle
• Posterior wall is reconstructed by suturing the triple layer medially to the inguinal ligament +/- iliopubic tract laterally

Question 13

Surface marking for deep inguinal ring

Answer 13

From Last’s - 1.25cm above midpoint of inguinal ligament (ASIS -> PT).

Evidence based answer is 1cm either side of the mid-inguinal point (ASIS -> PS)

Question 14

Structures passing through the deep ring

Answer 14

• vas
• vas deferens artery (superior or inferior vesicular artery)
• testicular artery and veins (usually 2)
• obliterated remains of process vaginalis
• genital branch of genitofemoral nerve
• autonomic nerves
• lymphatics
• NOT ILIOINGUINAL NERVE which enters from the side

Question 15

Spermatic cord contents

Answer 15

• vas deferens
  
  • vas deferens artery
  • testicular artery
  • obliterated processus vaginalis
  • genital branch of genitofemoral nerve
  • autonomic nerves
  • lymphatics

Question 16

Ilioinguinal nerve

Answer 16

• L1 nerve root
• 2cm superomedial to ASIS pierces IOM
• runs on cremaster
• initially anterior to cord then inferior when it passes through superficial ring
• supplies scrotal/labial and pubic skin
• at risk when incising external oblique, repairing superficial ring
• enters canal by piercing internal oblique NOT through deep ring

Question 17

Iliohypogastric nerve

Answer 17

• L1 nerve root
• 3cm superomedial to ASIS pierces IOM
• runs on internal oblique parallel to but 1-2cm above cord
• supplies suprapubic skin
• visualised when upper external oblique flap mobilised for 2+cm
• at risk with relaxing incision or superior sutures on mesh

Question 18

Why are patients at risk of a direct hernia after appendicectomy

Answer 18

Lowermost fibres of IOM and transversus supplied by L1 nerves which if divided can lead to a direct hernia due to bulging of the conjoint tendon with increased intra-abdominal pressure. At the level of the inguinal canal, however, the ilioinguinal is purely a sensory nerve (anterior scrotum/labia and adjacent thigh)

Question 19

Genital branch of genitofemoral nerve

Answer 19

• S2,S3
• enters canal with cremasteric vessels
• lies posterior to cord
• supplies scrotal/labial skin, medial thigh, cremaster
• at risk when cleaning the deep ring
• damage may lead to low lying testicle

Question 20

Pathophysiology of acutely incarcerated and strangulated hernia

Answer 20

Fascial defect or similar
Increased intra-abdominal pressure
Hernia enlarges 
Orifice becomes too tight to reduce
Venous obstruction
Congestion and oedema
Increasing bulk
Complete interruption of circulation
Gangrene of bowel

Question 21

Pathophysiology of chronically irreducible hernia

Answer 21

Fascial defect or similar
Increased intra-abdominal pressure
Hernia enlarges to point of irreducibility
Partial venous obstruction
Exudation into sac
Adhesions between bowel and sac
Hernia permanently irreducible

Question 22

Triangle of pain

Answer 22

Boundaries:

• Gonadal vessels medially
• lliopubic tract superiorly
• Relflected peritoneum laterally

Contents:

• Femoral nerve
• Lateral femoral cutaneous nerve
• Anterior femoral cutaneous nerve
• Femoral branch of genitofemoral nerve

Question 23

Triangle of doom

Answer 23

Boundaries:

• Vas deferens medially
• Gonadal vessels laterally
• Peritoneal edge posteriorly

Contents:

• External iliac vessels
• Genital branch of genitofemoral nerve
• Gonadal vessels