The appendix is a small, tube-like organ typically located in the lower right quadrant of the abdomen, attached to the large intestine. This standard placement means a surgical scar from an appendectomy is usually expected on the right side. When a scar appears on the left side, it is generally due to modern surgical techniques or, rarely, an unusual internal anatomy.
Typical Appendix Location and Standard Incision
The appendix is located in the right lower quadrant, attached to the cecum (the beginning of the large intestine). The classic site of tenderness in appendicitis is known as McBurney’s Point, which corresponds to the appendix’s base. This point is situated approximately one-third of the way along a line drawn from the right hip bone to the navel.
The traditional open appendectomy involved a small incision made directly over this point of maximum tenderness. This incision allowed the surgeon to access and remove the inflamed appendix. The resulting scar was predictably located in the right lower abdomen, establishing the expectation that an appendix scar belongs exclusively on the right side.
Laparoscopic Surgery and Variable Scar Placement
The most common reason for a left-sided scar is the widespread adoption of minimally invasive laparoscopic surgery. Instead of one large incision, a laparoscopic appendectomy uses multiple small incisions, called ports, for the camera and surgical instruments. A typical procedure involves three ports, strategically placed to give the surgeon the best angle to operate on the right-sided appendix.
The primary port, housing the camera, is often placed near the navel. The other two ports are used for instruments, and one is commonly placed in the left lower quadrant (left iliac fossa). Placing an instrument port on the left side provides the necessary wide angle for the surgeon’s instruments to work efficiently across the abdomen.
The scar on the left side is not the entry point for the appendix removal itself, but a small, secondary incision used to manipulate instruments. The appendix is usually removed through the umbilical port. Because these port incisions are small, they are sometimes misidentified as the main incision, leading to the assumption that the appendix was located on the left.
Anatomical Anomalies Placing the Appendix on the Left
In rare cases, the scar is genuinely located on the left because the appendix itself was positioned there. This occurs due to rare congenital conditions, primarily Situs Inversus Totalis. This anomaly is a hereditary condition where the major organs of the body are mirrored from their normal positions.
In a person with Situs Inversus, the entire digestive tract is reversed, placing the appendix in the left lower quadrant (LLQ). For example, the heart is on the right side of the chest, and the liver is on the left side of the abdomen. The incidence of this condition is very low, affecting approximately 0.001% to 0.01% of the population.
When appendicitis occurs in these patients, the pain localizes to the left lower quadrant, requiring a left-sided surgical approach. Other conditions, such as intestinal malrotation, can also cause the appendix to be in an abnormal position on the left. If an open appendectomy is performed on a patient with Situs Inversus, the resulting single incision will be on the left side, mirroring the classic right-sided incision.