Methods of opening of the posterior cranial fossa.
Crossbow section (Fig. 9). In this context trepanation hole is located under the powerful layer occipital muscles that if enough decompression prevents bulging. Extensive destruction of the occipital bone and rear arm Atlanta prevents "incursion" the cerebellum at the back of the hole and the compression of the medulla oblongata. Pre make ventricular puncture (see the brain) to decrease the intracranial pressure and venous stasis in the posterior cranial fossa.
Fig. 9. Crossbow incision (scheme).
The curved part of the section connects the origin of both the mastoid process, and vertical drops in the midline to the spinous apophysis V cervical vertebra. The aponeurosis cut strictly along the middle line of the neck ligaments, starting cut necessarily somewhat lower outside the occiput. Then cut the ligament and muscle layers of the skull and the spinous processes of the cervical vertebrae. Cross-section through the aponeurosis and muscle layers is carried out in hand, starting from the top of the middle section of the aponeurosis, keeping the area of the muscles and the aponeurosis in place attaching them to the top nuchal line occipital bone that provides durability when stitching of the wound. Muscle flaps separated by respetaron down and to the side; reveal the lower half of the scale of the occipital bone, adjacent departments of the mastoid process and the rear edge of the occipital foramen. Cutter make two holes respectively cerebellar hemispheres; expanding the openings with a wire cutter, a bone are removed. If necessary, widely expose the cerebellum hole extend to the lower section of the transverse sinus, and in hand - almost to the hole of the mastoid Vienna and mastoid process. The rear edge of the great occipital foramen removed for 3-4 see If the increase in intracranial pressure and the threat of embarrassment oblong brain repetiruyut the side of Atlanta. Opening of the Dura usually carry the Y-shaped, Phillips or a semicircular cut.
Horseshoe-shaped incision is carried out from the level of the top of one of the mastoid process to the top of another, some distance 3 cm from the ears (Fig. 10).
Fig. 10. Horseshoe-shaped incision; skin-muscle flap pulled downward; expand bone hole.
Fig. 11. The middle section: the incision of the skin and subcutaneous tissue; dissection musculoaponeurotic layer in the vertical direction with additional cross nadseni; skeletization scales occipital bone and rear arc Atlanta.
Fig. 12. The technique of removal of tumors of the cerebellum: 1 - the opening of cysts of the cerebellum and the exposure site angioretikulez; 2 - delete site angioretikulez with the help shpatelja and tip suction apparatus, coagulation vascular legs tumors; 3 - delete vnutrisustavno glial tumors method kustovaya with the spoon.
The horizontal part of the cut are conducted directly below the occiput. After scalping scales occipital bone flap of soft tissues turn to the neck; the opening of the posterior cranial fossa - as with crossbow access.
The middle section of the start 4 cm above the outer occiput and hold down the spinous apophysis VI cervical vertebra (Fig. 11). Muscle dissect the midline to the bone and is separated in both parties together with the periosteum, starting from the junction of the muscles of the upper back line and continuing to the parties to the mastoid bone. Transverse cross the deep fascia and muscles 3-4 cm from outside the occiput, leaving the bones strip these tissues, which is used when the stitches. Clipping strong tendons at the place of their attachment to the occipital bone, and allows Atlanta widely exposing and Traunreut bone. Occipital artery and large occipital nerves remain intact.
The middle section is much less traumatic than crossbow and a horseshoe, faster and stitching of the wound when it easier. Children up to
6-7 years through this section you can see both hemispheres of the brain. Access is facilitated, if you add partial crossbow cut the muscle layer in the form of letter T. If you have confidence in the median tumor localization the middle section can be applied in young people with thin and long neck, a narrow neck. With the localization process in cerebellar hemisphere or in the cerebellopontine angle in older children are more often applied horseshoe-shaped incision; in adults they are mainly used; the middle section may not be sufficient and with a median tumors, if the patient has a short, thick neck, flat-head, and usually poorly acting outside INION.
