Abdominal Hernias: Types and Surgical Management

An abdominal hernia is an abnormal protrusion of the abdominal contents through a weakness or defect of the abdominal wall, and can be congenital or acquired. There are multiple types of hernias based on the anatomic location and the underlying pathophysiology. The most common hernias encountered in surgical practice include ventral, inguinal, and femoral hernias. Hernias are most commonly diagnosed on physical exam (abnormal bulge or protrusion), but imaging studies can sometimes be helpful for a definitive diagnosis. The management consists of surgical repair. The decision for surgery is based on patients’ symptoms, their desire for surgical repair, and risks of incarceration and strangulation. Surgical options include open and laparoscopic approaches, with or without the placement of a prosthetic mesh.

Last update:

Table of Contents

Share this concept:

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email
Share on whatsapp

Overview

Definition

A hernia is an abnormal protrusion of the abdominal contents through a weakness or defect along the wall of the abdomen. Hernias can be congenital or acquired.

Epidemiology

  • 5 million Americans have hernias.
  • A majority of hernias are groin hernias (inguinal/ femoral).
  • ⅓ of all repaired ventral hernias are incisional hernias and the remaining ⅔ are primary ventral hernias.

Etiology

  • Some hernias can be congenital:
    • Inguinal (failure of the closure of the processus vaginalis)
    • Umbilical (present at birth in all infants, but most close within the 1st 2 years of life)
  • Acquired hernias are due to loss of the mechanical integrity of the abdominal wall:
    • Primary: A genetic component causes weakness of the abdominal wall.
    • Incisional: damage to abdominal wall muscles and fascia during surgery

Pathophysiology

  • A hernia has a hernia sac: an outpouching of the peritoneum, which covers the hernia contents
  • Reducible hernia:
    • Contents of the hernia can freely return to the abdominal cavity.
    • During an examination, the hernia can be pushed back in.
  • Incarceration:
    • Inability of the contents of the hernia to return to their original cavity
    • Presents with severe pain and nonreducible bulge
    • Symptoms of intestinal obstruction develop if intestines are incarcerated.
  • Strangulation:
    • Contents of the hernia are incarcerated.
    • Blood supply to the incarcerated organs is compromised, causing ischemia and resultant tissue death.

Anatomic classification

Various types of abdominal wall hernias can be defined by anatomic location:

  • Anterior hernia:
    • Epigastric
    • Umbilical
    • Spigelian
    • Incisional
    • Parastomal
  • Groin hernia:
    • Inguinal
    • Femoral
  • Pelvic hernia:
    • Obturator
    • Sciatic
    • Perineal
  • Posterior hernia:
    • Superior triangle (Grynfeltt hernia)
    • Inferior triangle (Petit hernia)
Types of hernias of the abdominal wall

Types of hernias of the abdominal wall

Image by Lecturio.

Ventral Hernias

Definition

Ventral hernias occur through a weakness in the anterior abdominal wall and can be congenital or acquired.

Anatomy

Layers of the abdominal wall include:

  • Skin
  • Camper’s fascia (subcutaneous fatty tissue)
  • Scarpa’s fascia (membranous layer of the anterior abdominal wall)
  • External abdominal oblique fascia and muscle (lateral), and rectus abdominis muscle (medial)
  • Rectus abdominis has:
    • Anterior rectus fascia
    • Rectus muscle
    • Posterior rectus fascia:
      • Ends midway between the umbilicus and pubic tubercle
      • The lower edge is referred to as the arcuate line.
    • Linea alba: fibrous band that runs midline between the 2 rectus muscles
  • Internal abdominal oblique muscle
  • Transversus abdominis muscle
  • Transversalis fascia (underlies the transversalis muscle and posterior rectus fascia)
  • Preperitoneal fat
  • Peritoneum
Layers of abdominal wall

Diagram of the layers of abdominal wall

Image: “Gray399” by Henry Gray. License: Public Domain

Types of ventral hernias

Epigastric hernias:

  • Hernias that occur along the linea alba, from the xiphoid process to the umbilicus
  • Constitute 1.6%–3.6% of abdominal wall hernias
  • 2–3 times more common in men
  • Small defects that produce pain disproportionate to their size

Umbilical:

  • Hernias that occur through the umbilical ring of the linea alba
  • Pediatric population:
    • The umbilical ring is open at birth (to allow passage of umbilical vessels).
    • Spontaneous closure generally occurs during the 1st 2 years of life and is closed in most children by 5 years of age.
    • Surgical repair is indicated if umbilical hernias persist beyond the 5th year of life with no decrease in the size of the defect.
    • Up to 8 times more common in children of African American descent
  • Adult population:
    • Most commonly acquired
    • More common in women and in conditions that cause increased intra-abdominal pressure:
      • Pregnancy
      • Obesity
      • Ascites

Incisional hernias:

  • Hernias that occur through the scar tissue of past surgical incisions due to poor wound healing and excessive tension
  • Risk factors for incisional hernia:
    • Obesity
    • Malnutrition
    • Chronic obstructive pulmonary disease
    • Diabetes mellitus
    • Chronic corticosteroid use
    • Surgical site infection

Spigelian hernias:

  • Hernias that occur through the transversus abdominis muscle aponeurosis (Spigelian aponeurosis):
    • Bound by the lateral edge of the rectus muscle medially and linea semilunaris laterally
    • Most common in the “Spigelian belt”: the transverse 6-cm zone around the arcuate line (lower edge of the posterior rectus sheath)
  • The majority of these hernias are small (1–2 cm) and most present during the 4th to 7th decades of life.
  • Difficult to identify on physical exam, often require imaging
CT of right Spigelian hernia

CT of right Spigelian hernia:
A: Hernia sac (arrow) containing loop of the small bowel (RA: right rectus abdominis)
B: Abdominal wall defect (circle)

Image: “Correspondence: Laparoscopic repair of abdominal wall hernia–“How I do it”–synopsis of a seemingly straightforward technique” by Berney CR. License: CC BY 4.0

Parastomal hernias:

  • Potential complication after creation of a stoma
  • Occurs with up to 50% of colostomies, less common with ileostomy
  • Asymptomatic in most cases and routine repair is not recommended
  • Obstruction or incarceration can occur in rare cases and require repair.

Surgical repair

Indications:

  • Strangulated hernias or hernias with incarcerated intestines need to be repaired emergently due to the risk of bowel necrosis.
  • Nonincarcerated hernias can be approached electively:
    • Should be repaired if the hernia causes pain or discomfort
    • Spigelian hernias should always be repaired due to the high risk of incarceration.

Primary repair:

  • Approximating the edges of the hernia defect with sutures
  • Suturing, by definition, is not tension-free as it entails pulling together the edges of the defect.
  • Thus, the rates of failure may be as high as 50%.
  • Generally, only suitable for very small defects (< 1 cm)
  • Other indications:
    • A contaminated surgical field, where the risk of mesh infection is unacceptably high
    • Hernias in children 

Mesh repair:

  • Involves placement of a prosthetic material to cover the hernia defect
  • Prosthetic materials can be synthetic (different types of polymers) or biologic (derived from human or animal tissues).
  • Synthetic meshes provide more durable repair and are preferred in the majority of cases.
  • Biologic meshes are preferred sometimes in a contaminated field to avoid synthetic mesh infection although evidence for their advantage in this situation is lacking.
  • Options for mesh placement:
    • Between the bellies of the rectus abdominis muscle (inlay)
    • Over the anterior aponeurosis of the rectal sheath (overlay)
    • Intraperitoneally (underlay)
    • Behind the rectus abdominis muscles (retro rectus)
    • Between the rectus abdominis muscle and the peritoneum (preperitoneal)
    • Between the internal oblique and transversus abdominis muscles that run behind the rectus abdominis muscle (intramuscular)
  • Laparoscopic versus open approach:
    • Most small- and medium-sized hernias can be repaired with either approach.
    • The chosen method largely depends on the surgeon’s expertise.
    • Very large hernias, especially those involving the loss of abdominal domain, are repaired in an open fashion. The repair process can be quite complex and is sometimes done in stages.
    • Laparoscopy has the advantages of a shorter hospital stay and faster recovery.

Complications:

  • Recurrence 
  • Mesh infection
  • Surgical site infection
  • Intestinal injury
  • Mesh-enteric fistula
  • Seroma: an accumulation of exudative secretions in potential spaces when the reabsorption capacity of the tissues is overwhelmed

Inguinal Hernias

Definition

Inguinal hernias occur through the floor or the internal ring of the inguinal canal.

Epidemiology

  • 75% of all hernias are inguinal.
  • Men are 25 times more likely to have a groin hernia.
  • The indirect variant is more common than the direct variant (2:1).
  • Most commonly occur on the right side
  • Strangulation occurs in 1%–3% of all inguinal hernias.

Classification

  • Indirect: 
    • The hernia sac passes through the internal inguinal ring toward the external inguinal ring and into the scrotum.
    • Frequently congenital and associated with patent processus vaginalis
  • Direct: 
    • The hernia sac protrudes anteriorly and is medial to the internal inguinal ring and inferior epigastric vessels.
    • Hesselbach’s triangle (site of direct herniation): formed by the inguinal ligament, inferior epigastric vessels, and rectus sheath
    • Mostly acquired secondary to muscular weakness and are more common in older men
  • Combined (pantaloon): both indirect and direct hernia components
Schematic diagram of the difference in location between direct inguinal hernias

Schematic diagram showing the difference in location between direct inguinal hernias, indirect inguinal hernias, and femoral hernias:
Indirect hernias occur through the internal inguinal ring. Direct hernias occur through the external inguinal ring, medially to the epigastric vessels. Femoral hernias occur through the femoral triangle, below the inguinal (Poupart’s) ligament.

Image by Lecturio.

Anatomy of the inguinal canal

  • An oblique passage in the inferior aspect of the abdominal wall of the inguinal regions
  • Directed downward and medially
  • 3.5–4 cm in length
  • Allows passage of the spermatic cord in men and the round ligament in women
  • 2 openings:
    • Deep (internal) ring
    • Superficial (external) ring
  • Processus vaginalis:
    • Peritoneal outpouching into the inguinal canal associated with the descent of testes during embryonic development
    • Normally obliterated by birth
    • Creates anatomical predisposition for herniation if not obliterated
Table: Boundaries of the inguinal canal
BoundaryLevel of the deep ringMiddleLevel of the superficial ring
Anterior wall Internal oblique External oblique External oblique aponeurosis External oblique aponeurosis (crura)
Posterior wall Transversalis fascia Transversalis fascia Conjoint tendon
Roof Transversalis fascia Arching fibres of internal oblique and transversus abdominis Medial crus of external oblique
Floor Inguinal ligament Inguinal ligament Lacunar ligament
Anatomy of the inguinal region and hernia

Anatomy of the inguinal region and hernia

Image by Lecturio.

Surgical repair

Indications:

  • Incarceration or strangulation (emergent)
  • Symptomatic hernia (associated with pain or discomfort)

Open approach

  • A transverse incision is made above the inguinal ligament, which is at the midpoint between the anterior superior iliac spine and the pubic tubercle.
  • The external oblique aponeurosis is incised, with care taken to identify the genital branch of the genitofemoral nerve and the ilioinguinal nerve.
  • The spermatic cord is mobilized and the hernia sac is dissected free.
  • The contents of the hernia sac are reduced.
  • The hernia sac can be reduced (direct), or the neck of the hernia sac can be ligated and excised (indirect).
  • Primary repair (tissue repair) is rarely used nowadays as the failure rates are quite high.
  • Options for tissue repair:
    • Bassini: approximation of the transversus abdominis and the conjoint tendon (internal oblique aponeurosis) to the inguinal ligament
    • Shouldice: 
      • Layered repair
      • Running suture to approximate the transversus abdominis aponeurosis to the inguinal iliopubic tract
      • Running suture to approximate the internal oblique to the inguinal ligament
    • McVay:
      • Interrupted, nonabsorbable suture to approximate the edge of the transversus abdominis aponeurosis to Cooper’s ligament
      • Cooper’s ligament and the transversus abdominis are secured to the iliopubic tract.
      • A relaxing incision is made in the anterior rectus sheath 1 cm above the pubic tubercle.
  • Mesh repair:
    • Lichtenstein repair
      • A synthetic mesh with a slit in the middle is inserted into the canal to accommodate the spermatic cord and wrap around it.
      • Using nonabsorbable suture, the mesh is secured to the pubic tubercle superiorly along the transversus abdominis and inferiorly along the shelving edge of the inguinal ligament.
    • Plug and patch:
      • A cone-shaped piece of polypropylene mesh is inserted into the internal ring.
      • A flat piece of mesh is used to reinforce the floor of the inguinal canal similar to the process used in Lichtenstein repair.

Laparoscopic approach:

  • Always involves mesh placement
  • Requires technical expertise
  • Totally extraperitoneal (TEP) technique:
    • Abdominal cavity is not entered.
    • Dissection is performed in the preperitoneal space with a balloon and insufflation.
    • Limited working space
  • Transabdominal preperitoneal (TAPP) technique:
    • Abdomen is entered using the open Hassan technique or Veress needle.
    • Peritoneum is taken down and mesh is placed in the preperitoneal space.
    • Larger working space

Complications:

  • Chronic groin pain 
  • Testicular atrophy (damage to the testicular artery)
  • Infertility (mesh fibrosis)
  • Orchitis: acute inflammation of the testis due to viral or bacterial infections
  • Seroma
  • Scrotal hematoma
  • Urinary retention

Femoral Hernias

Definition

Femoral hernias are hernias that occur through the femoral triangle (below the inguinal ligament).

Epidemiology

  • Up to 10 times more common in women than men
  • Occurs more commonly on the right side
  • The highest rate of strangulation among all hernias (10%–20%)
  • High likelihood of strangulation (40%); therefore, surgical intervention is always indicated

Anatomy

  • The femoral ring is roughly 1 cm in diameter and bound by:
    • Femoral vein laterally
    • Iliopubic tract anteriorly
    • Cooper’s ligament posteriorly
    • The pubic tubercle forms the apex of the femoral canal triangle.
  • The hernia will pass medial to the femoral vessels through the femoral canal.

Surgical repair

  • Open repair: 
    • McVay repair approximates the iliopubic tract to Cooper’s ligaments.
    • Preferred approach if there is strangulated bowel, as there is no need for mesh placement
    • The lacunar ligament should be divided if the incarcerated contents cannot be reduced.
  • Laparoscopic repair:
    • TEP laparoscopic approach
    • TAPP laparoscopic approach
  • Complications are similar to those seen in inguinal hernias.

References

  1. Malangoni, M.A., Rosen, M.J. (2012). In Mattox, K. L., et al. (Eds.), Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. pp. 1114‒1140.
  2. Turnage, R.H., Badgwell, B. (2012). In Mattox, K. L., et al. (Eds.), Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. pp. 1088‒1113.
  3. Brooke, D.C. (2020). Overview of abdominal wall hernias in adults. In Chen, W. (Ed.). UpToDate, Retrieved April 23, 2021, from https://www.uptodate.com/contents/overview-of-abdominal-wall-hernias-in-adults
  4. Ramsook, C. (2020). Inguinal hernia in children. UpToDate, Retrieved May 03, 2021, from https://www.uptodate.com/contents/inguinal-hernia-in-children
  5. Brooks, D.C., Hawn, M. (2019). Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults. UpToDate, Retrieved May 03, 2021, from https://www.uptodate.com/contents/classification-clinical-features-and-diagnosis-of-inguinal-and-femoral-hernias-in-adults

Study on the Go

Lecturio Medical complements your studies with evidence-based learning strategies, video lectures, quiz questions, and more – all combined in one easy-to-use resource.

Learn even more with Lecturio:

Complement your med school studies with Lecturio’s all-in-one study companion, delivered with evidence-based learning strategies.

🍪 Lecturio is using cookies to improve your user experience. By continuing use of our service you agree upon our Data Privacy Statement.

Details