Hernias With Related Anatomy

Hernia is a protrusion of a viscus or part of a viscus through its’ normal anatomical cavity.

Out of all hernias, groin hernias are the commonest (Inguinal hernia and femoral hernia)

To learn the basics of hernia, please read this article.

Groin Hernias

There are two types of groin hernias.

  • Inguinal hernia
    • Direct inguinal hernia
    • Indirect inguinal hernia
  • Femoral hernia
 
Incidence of groin hernia
  • Majority of inguinal hernias
  • Femoral hernias are rare, but common in adults
  • In adult males – Direct inguinal hernia is the commonest 
  • In adult females – Indirect inguinal hernia is the commonest followed by femoral hernia
  • In children – Indirect inguinal hernia is the commonest
  • In female children 
    • Groin hernias are rare 
    • Bilateral hernia present – Suspect testicular feminization syndrome
  • In male children
    • Incidence is 4% during infancy (Indirect inguinal hernia)
    • Due to failure of closure of processus vaginalis 
  • Groin hernia is more common on the right side
    • Due to late descent of right testis and following appendectomy
 

 Indirect Inguinal Hernia

  • Hernial sac is the remains of processus vaginalis 
  • Passes through the deep inguinal ring, inguinal canal and superficial inguinal ring 
  • Hernial neck lies medial to the inferior epigastric artery
  • Can descend up to the scrotum – Inguinoscrotal swelling 
  • Easily reduced spontaneously 
 
Direct Inguinal Hernia
  • Hernial sac lies behind the cord
  • Passes directly forward though the defect in the posterior wall (Fascia transversalis) of the inguinal canal
  • Hernial neck lies lateral to the inferior epigastric artery 
  • Typically doesn’t descend up to the scrotum – Inguinal swelling 
  • Not easily reducible 
 
Inguinal Canal – Anatomy
  • Lies obliquely above the medial half of the inguinal canal 
  • 6 cm long
  • Contents
    • Males
      • Spermatic cord
      • Ilioinguinal nerve
    • Females 
      • Round ligament of uterus
      • Ilioinguinal nerve
  • Superficial inguinal ring
    • Triangular opening
    • Located anterior to the pubic tubercle
  • Deep inguinal ring 
    • Oval opening
    • Located 1.3 cm above the inguinal ligament
  • Boundaries of inguinal canal 
    • Floor 
      • Inguinal ligament
      • Lacunar ligament
      • External oblique aponeurosis
    • Anterior wall 
      • External oblique aponeurosis 
    • Roof
      • Internal oblique
      • Transversalis fascia
    • Posterior wall 
      • Transversalis fascia
      • Conjoint tendon 
    • Medially
      • Superficial inguinal ring
      • Conjoint tendon
    • Laterally
      • Deep inguinal ring 
      • Transversalis fascia 
 
inguinal canal

 Hesselbach’s Triangle / Inguinal Triangle

  • Superiorly – Lateral border of rectus sheath
  • Inferiorly – Inguinal ligament 
  • Medial – Inferior epigastric artery
 
hasselbach's triangle
 
 
Femoral Sheath
  • Downward protrusion of the fascial envelope of the abdominal walls
  • Ends by fusing with the tunica adventitia of femoral vessels 
  • Three compartments present 
    • Medial – Lymphatics / Femoral canal 
    • Intermediate –  Femoral vein 
    • Lateral – Femoral artery 
  • Femoral nerve is not included in the femoral sheath
  • Allows the structures to move freely during hip movements 
 
 
Femoral Canal –  Anatomy
  • Medial compartment of the femoral sheath
  • 1.3 cm long
  • Upper opening is called femoral ring
  • Contents
    • Lymphatic channels
    • Deep inguinal node of Cloquet (Drains penis / clitoris)
    • Fatty tissues
  • Boundaries of femoral canal 
    • Anteriorly
      • Inguinal ligament 
    • Posteriorly
      • Pectineal ligament 
    • Medially
      • Lacunar ligament  
    • Laterally
      • Femoral vein
  • Femoral ring
    • It is the opening of the femoral canal
    • Covered by femoral septum 
    • Bounded by the same structures as the femoral canal
  • Importance
    • Allows femoral veins to expand when venous return increases
    • As it is a potential space – It is the site of femoral hernias
 
Femoral traingle

 

 
Femoral Hernia
  • Incidence : Rare
  • M : F ratio is 1 : 2.5
  • Right side more affected than the left
  • Passes though the femoral ring into the femoral canal 
  • Hernia appears on the thigh,  next to the saphenous opening (Compresses the saphenous vein)
  • Femoral hernias are small – Difficult to detect in obese
  • High risk of strangulation
  • Not reducible
  • No cough impulse
  • Contents – Only omentum | But can contain bowel in some occasions 
 
 

Management Of Groin Hernias

  • Identify and correct risk factors 
    • Increased intraperitoneal fluid
      • Ascities – CCF, CLCD, renal problems
      • Heavy lifting
      • Repetitive straining during micturition and defecation
      • Chronic cough
      • Obesity
  • Investigations
    • Clinical diagnosis
    • Investigations are done in diagnostic uncertainty
      • Ultrasonography
      • Contrast herniogram 
    • Assessment of fitness
  • Treatment 
    • Asymptomatic patients can be managed conservatively
    • Surgical management is widely performed



Surgical Management Of Inguinal Hernia

  • Methods 
    • Lichtenstein’s mesh repair (Open surgery)
    • Laparoscopic repair
  • Aim of surgery
    • Reduce hernial content
    • Remove hernial sac
    • Repair the defect
  • Indications of surgery
    • Symptomatic patients
    • Become irreducible
    • Sudden onset of pain with irreducibility – Demands emergency surgery  
    • All femoral hernia – Demands urgent surgery
  • Surgeries 
    • In adults
      • Primary unilateral : Mesh repair (Open surgery is preferred)
      • Primary bilateral: Mesh repair (Laparoscopic surgery is preferred)
      • Recurrent inguinal hernia : Repair (Laparoscopic surgery is preferred)
      • Prophylactic antibiotics – Given in mesh repair, but not in herniotomy 
      • Most causes are done as day surgery
    • Inguinal hernia in children
      • Herniotomy
    • Inguinal hernia in neonates
      • Need urgent surgery – High risk of strangulation 
 

Surgical Management Of Femoral Hernia

  • Methods 
    • Low crural (Lockwood)
    • High inguinal (Lotheissen) 
    • High extraperitoneal (McEvedy)
    • Laparoscopic method
  • Aim of surgery
    • Reduce hernial contents
    • Remove peritoneal sac
    • Repair the defect
  • Surgeries
    • Surgery should be done urgently – High risk of strangulation 


Complications Of Groin Hernia Repair

  • Haematoma 
  • Wound infection 
  • Mesh infection 
  • Recurrence 
  • Damage to cord structures 
    • Testicular atrophy
    • Ischaemic orchitis
    • Varicocele
  • Damage to ilioinguinal nerve
    • Nerve can be cut – Sensory loss over the lower groin or scrotum 
    • Nerve can be sutured – Develops chronic pain 
  • Missed Richter’s hernia (Only in femoral hernia)


Spigelian Hernia
  • Occurs through a defect in the bands of internal oblique muscle where it enters the semilunar line 
  • Present at the level of the arcuate line 
  • Incidence – 1% 
  • More common in females
  • Usually found near the iliac crest
    • As the hernia is deflected laterally by the external oblique muscle 
  • Occasionally the hernial sac may be found beneath the internal oblique muscle 
    • This can be confused with a rectus muscle haematoma
  • Clinical features
    • Painful lump at the iliac region
  • Management 
    • Diagnosis is confirmed by ultrasonography
    • Surgery – Open or laparoscopic repair 

 

 
Paraumbilical Hernia
  • Commonly occurs in adults
  • Hernia occurs through a defect in linea alba 
  • Defect is caused by increased intra-abdominal pressure
  • Contents – Extraperitoneal fat or omentum 
  • High risk of strangulation – Due to the presence of a narrow neck
  • Clinical features
    • Hernia distorting the umbilicus giving rise to a crescent shaped crest
      (Smiling face / sad face)
    • Usually irreducible
  • Management 
    • Identify and treat risk factors
    • Surgery 
      • Mayo’s repair 
        • Overlapping repair / Vest over pants 
        • Mesh repair  
Umbilical & Paraumbilical Hernia



Umbilical Hernia
  • Commonly seen in children
  • Hernia directly passes through the weak umbilicus
  • 95% resolves spontaneously by the age of 2 years
  • Clinical features
    • Lump at umbilicus
    • Increases in size during crying
    • Umbilical scar is visible in the overlying skin
  • Management
    • Surgery should be done after the third birthday


Incisional Hernia
  • Occurs at the sites of surgical access into the abdominal cavity through a weak scar 
  • Incidence – 12% at 10 years following surgery 
  • Commonly seen following surgical wound infection
  • Can minimize the occurrence by following Jenkins Rule during wound closure
    • Apply a continuous suture
    • Length of suture should be four times the length of the wound 
    • Start from 1 cm from the wound 
    • Bites should be taken at 1 cm intervals
  • Clinical features 
    • Lump, increasing in size
    • Pain 
    • Subacute intestinal obstruction 
    • Spontaneous rupture (Rare)
  • Management 
    • Mesh repair is preferred, can be either open or laparoscopic
Lumber Hernia
  • Primary lumber hernias are rare
  • Commonly occur as secondary hernias, following
    • Renal surgeries 
    • Lumber abscess
  • Management 
    • Direct anatomical repair with or without mesh repair 



Lumber Triangle / Petit’s Triangle
 
There are two lumber triangles
  • Superior lumber triangle – Not clinically significant 
  • Inferior lumber triangle 
    • This is commonly referred to as lumber triangle or Petit’s triangle 
    • Hernias can occur through this triangle
  • Boundaries of inferior lumber triangle / Petit’s triangle 
    • Inferiorly – Iliac crest  
    • Laterally – External oblique 
    • Medially – Latissimus dorsi 
 
Lumber triangles

 

 
Obturator Hernia
  • Occurs through the obturator canal 
  • Common in females
  • Hernia lies behind the pectineus muscle 
  • Most patients presents acutely with intestinal obstruction 
  • Require emergency laparotomy or laparoscopy 


Obturator Canal
  • Connects the pelvis to the thigh
  • Contents
    • Obturator artery
    • Obturator vein
    • Obturator nerve
Obturator canal

 

 
Epigastric Hernia
  • Hernia occurs through a defect in the linea alba at the epigastric region
  • Contents – Usually contains extra-peritoneal fat 
  • 30% of patients with epigastric hernia has a co-existing intra-abdominal disease producing upper GI symptoms 


Richter’s Hernia
  • It is a partial enterocele, where the anti-mesenteric border of the gut is strangulated in the sac
  • Partial intestinal obstruction occurs – Luminal patency is preserved 
  • Hernia becomes painful and irreducible 
  • Vomiting is a predominant feature – Due to paralytic ileus 


Maydl’s Hernia
  • Seen in large hernias
  • W-shaped loop of small bowel that lies in the hernial sac become strangulated by a bowel loop in the main abdominal cavity 


Pantaloon Hernia

  • Presence of both direct and indirect inguinal hernias on the same side


Littre’s Hernia
  • It is a hernial sac containing a strangulated Meckel’s diverticulum 
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