Abdominal Wall Hernias

Hernia

A hernia is a weakness in the layers of the abdominal wall resulting in a bulge under the skin.The pressure from inside the abdomen pushes the lining of the abdominal wall, the peritoneum, out through this area of weakness.

The hernia sac may start as a small lump, which disappears when the patient is lying down, and may be only apparent when standing or straining (coughing). Hernias are not always painful, they can be found incidentally. Over time hernias typically increase in size and can become quite large due to pressure from the abdomen pushing intra-abdominal fat and intestines (bowel) out, which can get stuck in the hernia sac (incarcerated) and potentially strangulate. For this reasons most hernias require surgical repair to alleviate symptoms and to prevent possible complications.

Common causes of hernias are abdominal straining (heavy lifting, constipation, urinary retention), persistent cough, smoking, poor nutrition, ascites (accumulation of abdominal fluid), undescended testes, obesity, peritoneal dialysis, physical exertion and previous surgery.

Types of Hernia

There are many types of hernias and most are classified by their anatomical location.Approximately 75% of all abdominal wall hernias are seen in the groin of which inguinal hernia is most common.

Image 1. Types of abdominal wall hernia including epigastric, umbilical, lateral, inguinal, femoral and incisional hernia.

Inguinal Hernia

An inguinal hernia is a groin hernia that results from protrusion of abdominal contents through the inguinal canal. There are two types of inguinal hernia;

• Direct inguinal hernia occur medial to the inferior epigastric vessels when abdominal contents protrude through a weakness in the posterior wall of the inguinal canal, which is formed by the transversalis fascia. This type of hernia usually occurs following heavy lifting.
• Indirect inguinal hernia occur when abdominal contents protrude through the deep inguinal ring, lateral to the inferior epigastric vessels. This is usually caused by failed closure of embryonic processus vaginalis.

Inguinal hernias usually present as a lump in the groin. They can become more prominent when coughing, straining or standing. The lump usually disappears when lying down. Inguinal hernias are usually asymptomatic, and only rarely painful. Although most are unilateral, up to 20% of patients go on to develop one on the contralateral side.

Femoral Hernia

Femoral hernias are a rare type of groin hernia. In contrast to inguinal hernia almost all femoral hernia occur in females due to the female pelvis being wider. In a femoral hernia the abdominal contents protrude medial to the nerves and vessels that supply the leg, through the femoral canal. Due to the femoral canal being narrow, femoral hernias are at increased risk of incarceration and strangulation of abdominal contents.

Umbilical and Paraumbilical Hernia 

An umbilical hernia is a type of ventral hernia, which is located in the central aspect of the umbilicus. They may be present from birth and in 85% of cases will close spontaneously. If the hernia persists beyond five years of age, they are less likely to improve and may require surgery. It is uncommon for umbilical hernias in children to strangulate. It is therefore reasonable to avoid surgery and adopt a wait-and-see policy.

In adults, hernias that occur around the umbilicus are termed “paraumbilical” hernias. The umbilicus is a natural weak point in the abdominal wall. They typically present as a “bulge” around the umbilicus. Apart from in pregnancy, they don’t disappear, and surgery is usually recommended. The diagnosis is usually made clinically.

Ventral Hernia

A ventral hernia results from a defect in the midline of the abdominal wall. They are also referred to as “epigastric” hernia. Most present with a small lump, that is usually asymptomatic, anywhere in the midline between the xiphoid process (lower end of sternum) and the umbilicus. They rarely cause complications. In some instances, imaging by Ultrasound or CT is required to confirm the diagnosis and help plan treatment.

Incisional Hernia

Incisional hernia is a type of hernia that develops due to incomplete healing of an abdominal wound. They therefore present as a lump at or near the surgical scar. Factors associated with an increased risk of incisional hernia include, multiple abdominal operations, obesity, poor nutrition or activities in the post-operative period associated with increased abdominal pressure (coughing, lifting, constipation, urinary retention). Surgery repair is commonly advised but not always required. Imaging by Ultrasound or CT may be required to confirm the diagnosis and extent of herniation, to help ascertain whether surgery is required.

Giant Abdominal Hernia

A giant abdominal wall hernia can develop from any long-standing hernia or as a result of delayed closure of the abdominal wall. There is usually a history of multiple failed repair attempts. The large defect allows for multiple loops of intestines and on occasion, other abdominal organs, to protrude into the hernia sac. Giant abdominal hernias are difficult to repair and often require a combination of mesh repair and/or component separation to bridge the large defect in the abdominal wall.

Parastomal Hernia

A parastomal hernia is a type of incisional hernia where there is protrusion of intra-abdominal contents though the abdominal wall defect created during stoma formation. Examples include ileostomy (terminal small bowel brought to the skin), colostomy (colon brought to the skin) gastrostomy (stomach or feeding tube brought to the skin) or urostomy (urinary diversion brought to the skin). Parastomal hernias are often difficult to diagnose and develop gradually over time. They often make it difficult to attach an appliance (bag) over the stoma and over time can increase dramatically in size. Treatment often requires more than one specialist and may involve either the refashioning of the stoma or repair of the hernia around the stoma with the use of mesh.

Spigelian Hernia

A spigelian hernia is a hernia that extends through the linea semilunaris, the line between the lateral edge of the rectus abdominis muscle and the oblique muscles of the abdominal wall. They almost always develop in the lower abdominal wall, more commonly on the right. They usually present with a lump and due to their small size, are at high risk of strangulation. Imaging by Ultrasound or CT is usually necessary to establish the diagnosis.

Recurrent Hernia

A recurrent hernia is the recurrence of a hernia following surgical repair. It usually presents as a lump at or near the site of previous repair. It needs to be differentiated from other causes, such as seroma (fluid collection) or hematoma, and imaging is sometimes helpful. A recurrent hernia usually requires further surgical repair. Unfortunately the success rate of the subsequent repair is less and it is associated with increased rate of complications.

Sportsman Hernia

A sportsman hernia is a chronic exercise-related groin pain associated with incipient direct bulge of the inguinal wall whenever the abdominal muscles contract forcefully. The pain develops during exercise, is usually unilateral and is located just above the inguinal ligament at the lateral aspect of rectus abdominus. The majority of the patients are young adult males. There is often no objective physical examination findings. A cough impulse is either weak or absent. Imaging by Ultrasound, CT or MRI may be helpful in showing a direct bulge of the posterior inguinal wall when forcefully contracting the abdominal muscles.

How can a hernia be treated?

The only definitive treatmentof a hernia is through surgical repair, which may be done viaconventional (open repair) or minimally invasive (laparoscopic) surgery. Operation is usually advised because a hernia will not go awayand may get larger: it can cause inconvenient symptoms and there is a small risk of strangulation or incarceration. If a hernia is causing no problems, then an operation is not essential, and you can discuss the need for operation with the surgeon. Umbilical and femoral hernias should be operated even in the absence of symptoms due to the greater risk it carries for complications such as incarceration and strangulation.

Dr Papoulas is primarily using the minimally invasive technique for hernia repair via 3 tiny incisions. Most patients are discharged on the same day and only a small number of patients require an overnight stay in the hospital, generally related to other pre-existing medical conditions.