Craniotomy
A craniotomy is a surgical procedure in which a part of the skull is temporarily removed to expose the brain and perform an intracranial procedure. The most common conditions that can be treated via this approach include brain tumors, aneurysms, arterio-venous malformations, subdural empyemas, subdural hematomas, and intracerebral hematomas. Specialized tools and equipment are utilized to remove the section of bone, which is called the bone flap. The bone flap is temporarily removed, held at the surgical instrument table, and then placed back after the brain surgery has concluded. In some cases, depending on the etiology and indication for the procedure, the bone can be discarded, stored in the abdominal subcutaneous space, or cryopreserved under cold storage conditions. If the bone flap is discarded or not placed back into the skull during the same operation, the procedure is called a craniectomy. In a decompressive craniectomy used for the treatment of malignant brain edema, the bone flap is placed back a few weeks after the brain swelling has improved. The surgical procedure to reconstruct and place the bone flap back into the skull during a second intervention is known as cranioplasty.
From a historical context and perspective, cranial interventions varied from a single burr hole trephination to a larger craniectomy. Modern craniotomies are performed by connecting a series of burr holes. Although trephination is the oldest cranial surgical technique with ancient reports dating back to 2300 years, our current modern surgical technique for a craniotomy is the final cured result of the procedure introduced at the end of the 19th century by the self-educated surgeon Wilhelm Wagner. Although it was much later in the course of history that the transition from trephination to a tailored resection via craniotomy happened, ancient civilizations, such as the Incas in Peru, must have had some basic familiarity with anatomy and surgical interventions despite their rudimentary knowledge of pathology.
Depending on the type of intracranial lesion, pathology, and the surgical approach, some craniotomy procedures can be assisted by neuronavigation guidance based on magnetic resonance imaging or computed tomographic scans to tailor the procedure to the size of the tumor using the smallest incision possible. Neuronavigation is a modern computerized technology that can help surgeons localize the pathology more precisely by merging a series of craniofacial points in the patient. Neuronavigation offers better guidance, orientation, and localization. It provides a higher level of confidence for the surgeon and an improved outcome for the patient 1)
Indications
The identification of gyri and sulci before can help us delimitate the intracranial lesions and preserve as much as possible the neurofunctional and eloquent areas.
Craniotomies are often a critical operation performed on patients suffering from brain lesions or traumatic brain injury (TBI), and can also allow doctors to surgically implant deep brain stimulators for the treatment of Parkinson's disease, epilepsy and cerebellar tremor. The procedure is also widely used in neuroscience for extracellular recording, brain imaging, and for neurological manipulations such as Electrostimulation and chemical titration.
A craniotomy is distinguished from craniectomy (in which the skull flap is not immediately replaced, allowing the brain to swell, thus reducing intracranial pressure) and from trepanation, the creation of a burr hole through the cranium into the dura mater.
One of the problems in neurosurgery is how to perform rapid and effective craniotomies that minimize the risk of injury to underlying eloquent structures. The traditional high-powered pneumatic tools and saws are efficient in terms of speed and penetration, but they can provoke bone necrosis and sometimes damage neurovascular structures.
As an alternative, the piezoelectric bone scalpel (piezosurgery), is a device that potentially allows thinner and more precise bone cutting without lesioning neighboring delicate structures, even in the case of accidental contact.
From January 2009 to December 2011, 20 patients (8 men and 12 women), 19 to 72 years of age (mean: 49.3 years) were treated using piezosurgery. Surgery was performed for the removal of anterior cranial fossa meningiomas, orbital tumors, and sinonasal lesions with intracranial extension. Results The time required to perform craniotomy using piezosurgery is a few minutes longer than with traditional drills. No damage was observed using the piezoelectric device. Follow-up clinical and neuroradiologic evaluation showed a faster and better ossification of the bone flap with good esthetic results. Conclusions Piezosurgery is a new promising technique for selective bone cutting with soft tissue preservation. This instrument seems suitable to perform precise thin osteotomies while limiting damage to the bone itself and to the underlying delicate structures even in the case of unintentional contact. These advantages make the piezoelectric bone scalpel a particularly attractive instrument in neurosurgery 2).
Types
see Awake craniotomy…
Surgical Technique
All procedures except awake craniotomy are performed under general anesthesia. Indwelling Foley catheters, arterial lines, and peripheral intravenous lines.
Multiple craniotomy
Multiple craniotomies have been performed for resection of multiple brain metastases in the same surgical session with satisfactory outcomes, but the role of this procedure in the management of multifocal and multicentric glioblastomas is undetermined, although it is not the standard approach at most centers.