Shipo's triangle is considered in the topographic anatomy of the head. Its clinical significance is very great. You need to know why this triangle is limited and what is its feature (importance). The detailed structure and clinical significance of this organ we will consider in this article.
Exterior view of the Shipo triangle
The structure of this triangle we will consider in this figure.
The mastoid process is indicated by number 1. This process is part of the temporal bone.
In front of the mastoid process, the external auditory meatus is located, it is indicated in the figure by number 2. After dissection of soft tissues and exfoliation of the periosteum in the anteroposterior region, you can see the "triangular site", which was called Shipo.
The borders of the Shipo triangle
On top of the line, which is a continuation of the zygomatic arch, is indicated by number 3. In front is a vertical line drawn along the rear edge of the external auditory meatus. This line is indicated by number 4.
The back and bottom marked by the crest of the mastoid process. This line is the third border of the Shipo's trepanation triangle. This line is marked with the number 5.
The clinical significance of the triangle
In this formation, with purulent inflammation of the air cells (mastoiditis), trepanation of the mastoid process can be performed. This procedure is called anthratomy.
To this triangle are adjacent formations that can be damaged during trepanation of the process.
What formations adjoin to a triangle?
The surgical anatomy of the mastoid region of the Shipo triangle is such that the channel of the facial nerve is located in front of the triangle. This formation is indicated in the figure under the number 6.
Above is the middle cranial fossa, as well as the temporal lobe of the brain. These formations are indicated by number 7.
Behind and below is the sigmoid sinus of the dura mater, which is indicated by the number 8.
What is the essence of the triangle?
Recall that the Shipo triangle has important clinical significance. Where can this value be needed? The answer is simple - in operative surgery (emergency surgery). In the event that the doctor will need to make an antrotomy, then he will need to get strictly into the Shipo triangle, without damaging its borders.
If the operation is not performed correctly, then this is fraught with serious (fatal) consequences for the patient.
Within the boundaries of the Shipo triangle there is a resonant cavity, it is also a mastoid cave, this cavity is communicated through the entrance to the cave with the tympanic cavity of the middle ear. The mastoid deepening is about 12 millimeters long and about 7 millimeters wide is located at a depth of 1.5-2 centimeters of the bone element of the mastoid process. The size of the cave is variable due to the structure of the mastoid process (pneumatic, sclerosis, or diploic).
The upper border, it is the wall, isolates the cave with a typical head fossa. In its medial wall there are 2 elevations, including the lateral semicircular canal, as well as the path of the external nerve. To the back wall of the cave, especially in brachycephalus, since they have a poorly developed mastoid process, because of this the sigmoid venous sinus is closely adjacent. But usually this sinus is separated from the cave by a very thick bone plate.
Triangle Discovery History
The Shipot triangle was discovered by a French neurosurgeon named Anthony Shipo in 1894. He discovered this structure and called it the optimal site of intervention for mastoidectomy. His author’s name for this formation was “the site of the attack during mastoidectomy”.
Subsequently, doctors outwardly described this area as follows: a smooth triangle, which is located on the mastoid process, namely on the temporal bone, near the external auditory canal. The area is limited to serious, clinically important formations. Constant trainings were held, where doctors were trained to carry out this procedure correctly, because the slightest mistake can result in disability or even death of the patient. But the question arises of how such an operation was carried out before. The answer is simple - it was performed according to the square method, of course, it was not so successful, and the wound healing time was very long. In addition, the area of surgical intervention was a quarter of the face.