Surgery of the cranial vault

Indications and anesthesia methods

Surgical interventions on the cranial vault are required for a wide range of pathologies. All indications can be divided into three main groups depending on the anatomical structures involved:

• Soft tissue disorders: include various traumatic injuries, benign neoplasms (e.g., atheromas), and other tumors.
• Cranial bone pathologies: surgery is indicated for fractures and other trauma, purulent-necrotic processes (osteomyelitis), and bone tumors.
• Intracranial lesions: interventions are life-saving for blood accumulations (epidural and subdural hematomas), abscess formation, as well as tumors of the brain and its meninges.

Anesthesia The choice of anesthesia method depends on the scope of the surgery. The primary and most preferred type is multicomponent endotracheal anesthesia, which must be accompanied by the administration of muscle relaxants and mechanical ventilation. If a minor operation is planned exclusively on soft tissues, local anesthesia is acceptable. In such cases, infiltration anesthesia is used (utilizing a 0.5% novocaine solution) combined with the regional administration of 5–10 ml of a 2% novocaine solution directly at the exit points of sensory nerve trunks.

Creation of surgical access

Proper surgical access is the key to a successful operation and minimizing complications. Incisions on the cranial vault have strict topographical patterns.

Rules for incision and flap creation:

1. Direction: incisions should preferably have a radial direction. This is a critical rule, as the incision line must strictly coincide with the course of neurovascular bundles to avoid their transection and subsequent tissue necrosis.
2. Flap type: a full-thickness cutaneous-aponeurotic flap is formed.
3. Nutritive pedicle: the base of the flap (its nutritive pedicle) must always be located at the border of the cerebral and facial parts of the skull, where major vessels supplying adequate blood flow to the tissues pass.
4. Separation and protection: the created flap is carefully separated from the underlying periosteum and reflected downward. To prevent drying and infection, it must be wrapped in gauze sponges generously moistened with a 3% hydrogen peroxide solution.

Technique of craniotomy execution

Craniotomy is a complex, multi-stage process requiring high precision. General stages include bone preparation, drilling, and ensuring reliable hemostasis.

Main stages:

• Bone preparation: using a raspatory, the surgeon displaces the periosteum. The area of exposed bone must equal the width of the planned burr hole plus an additional distance (about 1.0–1.5 cm) for the free passage of a surgical wire saw or rongeurs.
• Drilling: performed using a manual or electric trephine with a spear-shaped burr. A sure sign that the instrument has passed through the outer compact layer and entered the spongy substance is the appearance of blood-stained bone dust (reaching the diploic layer). After this, the spear-shaped burr must be replaced with a conical or spherical one for safe passage through deeper layers.
• Depth control: drilling is stopped immediately once the instrument reaches the inner glassy plate (lamina interna). Remaining thin fragments of the inner plate are carefully removed using anatomical forceps or a sharp surgical bone curette.
• Hemostasis: bleeding from damaged diploic vessels is stopped by thoroughly rubbing sterile bone wax into the edges of the bone wound.

Resection craniotomy

Resection craniotomy is a type of cranial bone surgery, the essence of which is the complete removal of a bone fragment without returning it to its place (the defect remains open or is closed with an implant at subsequent stages).

Technique features: During the procedure, periosteal displacement, bone flap creation, sawing, and bone removal are performed sequentially. To enlarge the opening and remove bone tissue, the edges of the formed defect are rongeured using special neurosurgical rongeurs (Borchardt or Luer rongeurs are used).

Important nuance: bone biting should be performed in small areas. This technique leads to local compression of the bone tissue and mechanical disruption of the structure of the diploic bone trabeculae, which itself promotes effective bone hemostasis.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Anatomical features of neurovascular bundles of the cranial vault
• Technique of using Borchardt and Luer rongeurs
• Multicomponent endotracheal anesthesia: drugs and stages
• Differential diagnosis of epi- and subdural hematomas
• Composition and application of surgical bone wax for hemostasis

Other topics in the "Head Surgery" section

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