These are rare hernias that occur in a line that runs from the belly button towards the hip bone. These hernias usually occur between the muscle layers, where the top muscle layer is usually intact. This means that the swelling may not be obvious, making the hernia harder to spot than the more common types like groin and midline hernias. The defects in the abdominal wall is also quite small. This in combination of the fact that bowel can get trapped between the muscle layers, increases the risk of strangulation.
People with a Spigelian hernia may notice pain at the side of their lower abdomen, which can worsen with coughing, straining, or exercise. Sometimes a small lump may appear, especially when standing, but disappear when lying down.
Repair or not
These hernias maybe difficult to diagnose. As a result some form of imaging such as a CT scan is essential. Once the diagnosis is confirmed, a repair is nearly always recommended due to the risk of strangulation.
Open or key-hole surgery
Because the top layer of muscle is intact, these hernias can be very difficult to detect during open surgery especially as the lump/ bulge can disappear when the patient is lying flat on the operating table. For this reason, laparoscopic/ key-hole surgery is usually recommended unless the patient has risk factors for a general anaesthetic, in which case the hernia can be marked before surgery, with the patient standing up, to aid its location during the surgery. Similar to other abdominal wall hernias, a mesh is recommended to strengthen the muscle layers and prevent recurrence. As these are rare hernias, they are best operated by specialist surgeons.