Clinical aspect of appendix


Appendix is important because of  its surgical problem. It easily gets infected because of blockage of its small lumen. In order to remove it, a special type of incision is used- called gridiron incision, a muscle splitting incision.

Gridiron incision-

This incision is made into the anterior abdominal wall without cutting through their muscles. It is therefore called the split-muscle incision. This incision, takes into consideration, the path or course of the fibers of the muscles of the anterior abdominal wall. Hence it is noted that the external muscle/ aponeurosis runs downwards and forwards just like the external intercostal muscle. This is followed by the internal oblique muscle and aponeurosis which runs upwards and forwards and then by the transverses abdominis which runs transversely. A good example of the gridiron incison is that made for appendicectomy in order to expose the caecum and the appendix which the caecum carries. In this incision the knife is passed through the so called McBurney’s point, which is a point placed at the junction between the lateral and intermediate 1/3 of the line joining the umbilicus with the anterior superior iliac spine on the right. This incision runs downwards and forwards along the McBurney’s point and passes through the following layers

  • 1. Skin

  • 2. Campers fascia

  • 3. Scarpa’s fascia

The next layer is the layer of external oblique apneurosis and muscle

The fibers of this layer are split to make room for the incision rather than using a knife.

The next layer is the layer of the internal oblique and again the fibres of this muscle/aponeurosis are split along their course, which means the split runs upwards and forwards.

Finally the split in the fibers of the transversus abdominis runs transversely.

After the layers of the muscles, we then reach the parietal peritoneum. This peritoneum is divided using a knife  longitudinally or transversely in order to expose the peritoneal cavity. The appendix may lie behind the caecum and this is the position preferred in 75% of cases- i.e. it is retrocecal or retroileal.

It also can lie in front of the cecum, i.e. pre-ileal or it may be pelvic in position thereby lying in the abdominopelvic corridor or within the greater pelvis. It may be long or short and it may have various types of curvature. The cecum itself may be retroperitoneal which then renders the operation more delicate. But in most cases it is intraperitoneal and it can then be easily delivered through the incision to the outside where operation on its contained appendix takes.

After the procedure, the surgeon does not bother to stitch back the muscular layers. But he stitches the skin, superficial fasciae and parietal peritoneum. It is believed that the muscle fibers will realign once the operation is finished and therefore this method obviates the need for incision, or stitches into the muscles which normally will cause scar formation.







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Creator: Oluwole Ogunranti