Fig. 52b. Exposure of the Branches of the Middle Meningeal Artery. Second stage. The trephine-holes have been enlarged with the craniectomy forceps in the required directions.
The incision commences immediately posterior to the external angular frontal process, curves upwards and backwards along the temporal crest, and terminates in front of the tragus of the ear. The flap, comprising skin, temporal fascia and muscle, and pericranium, is turned to its zygomatic base and all bleeding-points secured.
The subsequent procedures vary according to the condition of the bone:—
If there be no fracture of the bone, the pin of the trephine is applied to the indented spot and the disk of bone removed. After the removal of the disk the clot will be exposed; but, in order to obtain full exposure, the gap must be enlarged with the craniectomy forceps, mainly in the upward and downward directions.
If a fissured fracture be found, the trephine is applied in close relation to the intersection of the line of the artery and the line of the fracture, the gap being enlarged in the required direction.
When the fracture is comminuted, the fragments of bone are either elevated or removed until sufficient room has been obtained.
The greater part of the clot can be removed with a Volkmann spoon, or with an ordinary teaspoon, and the region flushed out with hot saline solution.
To secure the bleeding-points.
When the artery is injured beyond the limits of the gap, the bone must be nibbled away till the bleeding-point is exposed. In some cases it may be necessary to remove a considerable portion of the bone entering into the formation of the temporal fossa. In the meantime, hæmorrhage may be controlled by plugging towards the base of the skull with strips of gauze. Sufficient room having been obtained, the gauze is withdrawn, when smart sponging should enable the operator to determine the source of the hæmorrhage. At this stage of the operation, a head-lamp is useful. After the exposure of the bleeding-points, the following measures can be adopted whereby to arrest the bleeding:—
(a) The application of a ligature or of silver ‘clips’ (see [Fig. 6]) on either side of the bleeding-point.