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What is Spigelian hernia and explain in detail?
A Spigelian is the type of ventral hernia where aponeurotic fascia pushes through a hole in the junction of the linea semilunaris and the arcuate line creating a bulge. It appears in the abdomen lower quadrant between an area of dense fibrous tissue and abdominal wall muscles causing a (Spigelian aponeurosis).It is the protuberance, of omentum, adipose tissue, or bowel in that weak space between the abdominal wall muscles, that ultimately pushes the intestines or superficial fatty tissue through a hole causing a defect. As a result, it creates the movement of an organ or a loop of intestine in the weakened body space that it is not supposed to be in. It is at this separation (aponeurosis) in the ventral abdominal region, that herniation most commonly occurs.

Spigelian hernias are rare compared to other types of hernias because they do not develop under abdominal layers of fat but between fascia tissue that connects to muscle.  The Spigelian hernia is generally smaller in diameter, typically measuring 1–2 cm., and the risk of tissue becoming strangulated is high.

Signs and symptoms
Individuals typically present with either intermittent pain (coming and going), a lump, or mass all which are classic signs of a bowel obstruction. The patient may have a protuberance when standing in an upright position although discomfort can sometimes be confused by its anatomical region for a peptic ulceration. The bulge may be painful when the patient stretches but then goes away when they are lying down in a resting position. However, a number of patients present with no obvious symptoms but vague tenderness along the area in which the Spigelian fascia is located.

Diagnosis
Ultrasound Imaging or a CT Scan will provide better imaging for the detection of a hernia than an xray. The ultrasound probe should move from lateral to medially, a hypoechoic mass should appear anteriorly and medially to the inferior epigastric artery during Valsalva maneuver. The diagnosis of a Spigelian hernia is traditionally difficult if only given a history and physical examination. People who are good candidates for elective Spigelian hernia surgery, not only but also, after receiving an initial diagnostic consultation by a licensed medical professional, will be advised to see a physician to schedule surgery.

Treatment
The Spigelian hernia can be repaired by either an open procedure or laproscopic surgery because of the high risk of strangulation; surgery is straightforward, with only larger defects requiring a mesh prosthesis