Spigelian Hernia Symptoms

Hernia occurs when an organ or the fascia of an organ bulges from a weak spot in the wall of the body cavity that contains that organ. Abdominal hernia occurs when weak spots form in the abdominal wall due to straining of the abdominal muscles.

The abdominal muscles are a group of muscles called transversus abdominis, rectus abdominis, external oblique, and internal oblique muscles. Spigelian hernia is a rare type of abdominal hernia that occurs through the linea semilunaris.

It was Adriaan van den Spieghel, an anatomist from Belgium, who proposed the term 'Linea semilunaris' for the lateral edge of the rectus sheath. The term 'Spigelian hernia' was first used in 1764 by a Flemish anatomist called Josef Klinkosch to describe a defect in the linea semilunaris (semilunar line).

This form of hernia occurs due to defects in the Spigelian fascia, which is the section of the aponeurosis (sheet of fibrous tissue that binds muscles together) of transversus abdominis that is lateral to the edge of the rectus abdominis muscle, but medial to the linea semilunaris. In most cases, the herniation occurs at or below the arcuate line.

Also known as Linea semicircularis, arcuate line is a crescent-shaped line that marks the lower limit of the posterior layer of the sheath of the rectus abdominis muscle.

It is difficult to diagnose Spigelian hernia as its symptoms are vague and mimic other medical problems. Thus, it is often mistaken for other health conditions associated with the abdominal region.

In case of most types of hernias, the herniation in the abdominal region takes place subcutaneously underneath the fat layers. This is the reason why, an abnormal swelling can be felt. This is not the case with Spigelian hernia. This type of hernia is mostly interparietal. This means that the hernia sac is present between the layers of the abdominal wall.

The hernial sac, as well as the orifice may not always be felt by palpation. As it is a sub-muscular hernia, there is no external sign of swelling or lump. To add to that, the size of hernia is 1 to 2 cm in diameter in majority of cases. Therefore, the detection of this type of hernia may not be possible with physical examination alone.

The characteristic symptoms of hernia may not be observed in a person affected by Spigelian hernia. Here are some of the symptoms that may be experienced by the affected individuals:

• A lump may be felt by patients who have less fat in the affected abdominal area.

• Intermittent pain in the actual location is a noticeable sign. Pain may worsen on straining or coughing.
• Abdominal discomfort is one of the commonly manifested indicants of Spigelian hernia.
• The affected individual may experience a dull pain in the immediate area.
• In some people, bowel obstruction may be observed.

Most hernias occur in the area where the Spigelian fascia is the widest. Herniation could occur in the area between the linea semilunaris and the inferior epigastric vessels. The causes of this type of hernia are similar to other types of hernia.

Here are some of the common contributing factors:

• The abdominal muscles could weaken due to strain during childbirth. This makes multiple pregnancies a risk factor for hernia in case of women.
• People who are affected by obesity are at a greater risk of developing hernia.

• Straining of the abdominal muscles that may occur due to lifting weights, or performing any activity that causes an increase in the intra-abdominal pressure could lead to this condition.

• Weak spots could develop in the abdominal wall in people who have undergone surgery involving the abdominal region. An injury affecting the abdominal region could also be a contributing factor.
• Chronic constipation that causes a person to strain during bowel movement could also put him/her at a risk of developing abdominal hernia.

Most of the patients who are diagnosed with Spigelian hernia lie in the age group of 40 to 70 years. The condition is more likely to be symptomatic in people who have crossed the age of 50 years.

In many instances, this type of hernia remains undetected for a very long time. If doctors suspect that an individual has hernia, they examine the abdomen for the presence of any soft lumps. Certain imaging tests (CT scan, abdominal ultrasound) are usually conducted.

The imaging tests mostly focus on the arcuate line of abdomen (or linea arcuata), as the hernia is present in this section in most cases. It is assumed that the absence of posterior rectus sheath increases the chances for the development of hernia in the arcuate line.

Surgery is often recommended if the diagnostic tests are indicative of hernia. This is mainly due to the fact that incidence of strangulation is high in case of this hernia. Surgery becomes a necessity when the hernia can no longer be pushed back into place, and there is a risk of blockage in the intestine due to a part of the intestine getting trapped.

Strangulation is a life-threatening complication wherein the blood supply to that part of the intestine may get cut off, thereby causing tissue death. Doctors may either perform an open surgery or follow a laparoscopic procedure to push back the hernia into place.
                 In an open surgery, an incision is made in the abdomen to push the hernia back.

It also involves mending the weak spot or defect in the abdominal wall. In some cases, a surgical mesh is stitched over the defect. The recovery is faster in case of the minimally invasive laparoscopic surgery. In the laparoscopic surgery, the abdomen is inflated with carbon dioxide.

Small incisions are made in the abdominal region, and a laparoscope is inserted through an incision. The laparoscope transmits detailed images on video monitors. The surgeons refer to these images as they push back the hernia and mend the defect. This procedure is minimally invasive, which is why recovery is faster.

The risk of scarring is minimal, and the intensity of postoperative pain is likely to be less. 
Though Spigelian hernia is quite rare, and accounts for less than 2% of all hernias, it can be life-threatening in the event of strangulation.

Timely medical intervention in the form of hernia repair surgery can help in minimizing complications such as incarceration and bowel obstruction, which may result due to a delay in diagnosis and treatment. Though the symptoms may not be specific, the best option is to seek medical help on experiencing any of the aforementioned symptoms at the earliest.

Disclaimer: The information provided in this story is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.