Causes and purposes of cranioplasty
Cranial repair is a common procedure in brain surgery to repair the skull in response to traumatic brain injury resulting in a skull defect. Reasons for cranial repair: Cranial trauma and brain surgery (mainly acute stage aneurysm, cerebral hemorrhage, etc.) to remove bone flaps. As the shape of the cranial defect area changes, the scalp is affected by atmospheric pressure, which causes it to invaginate and compress the brain tissue. Often, the bone window is fuller in the morning, while the depression is more pronounced after walking or at night.
Patients with cranial defects often have heavy insecurity and other thought burdens, and can cause headache, dizziness, fear of vibration and other syndromes. The longer the cranial defect, the higher the incidence of cranial defect syndrome and secondary brain damage. In order to restore the cranial cavity confinement, keep the physiological intracranial pressure stable and reduce the cranial defect syndrome. Cranial bone repair should be performed for cranial defects of 3 cm or more in diameter, without muscle coverage and without contraindications. Addressing the absence of effective protection of brain tissue in the defect area, impaired blood supply, and abnormal cerebrospinal fluid circulation also requires addressing the issue of shape repair plasticity. The timing of surgery is generally considered appropriate for repair 3~6 months after craniotomy, where the pressure at the defect site is not high and there is no infection, ulceration, or other factors that are detrimental to incision healing.
Common cranial repair methods and materials include three main types.
1.Titanium plate.
For small defects that are more planar, two-dimensional titanium plates can be used for fixation. For larger defects involving the frontotemporal area, three-dimensional plastic titanium plate is a better choice. At present, 95% of patients in our department use three-dimensional plastic titanium plate, the patient only needs to receive a CT examination, complete the three-dimensional reconstruction of CT data, then the digital design of the restoration on the computer, complete the simulation of the assembly, the design data using digital molding technology to produce the restoration model, and then use digital manufacturing technology to produce titanium restorations, compared to the model of titanium alloy cutting edge to get the restoration. Since the digital restoration data comes directly from the patient, it can fit the broken part very precisely.
Digital design and fabrication of cranial restorations is a new technology that is better in all aspects, eliminating the drawbacks of traditional manual fabrication and greatly reducing the patient’s pain reducing the operation time by half. Good patient appearance recovery: For patients with cranial defects in the frontal surface and other areas, the subtle differences in the restorations can greatly affect the aesthetics. The digital restoration fits precisely to the broken area, which improves the patient’s appearance, self-confidence and quality of life. Treatment risks are also greatly reduced, and the patient’s post-operative recovery period is shortened so that he or she can resume work and integrate into society more quickly.
2.Plexiglass or silicone plates.
Plexiglass or silicone plate is irritating, will age over time, hardness is not enough, due to local collision and cause the rupture of the plexiglass sheet; produce subcutaneous fluid, and there is the possibility of infection leading to failure, sometimes the infection is produced after a longer period of time after surgery, and is rarely used.
3.Autogenous skull flap.
After craniotomy for any reason, the cranial flap can not be implanted back immediately in situ, but it can be preserved and used by autologous subcutaneous embedding. Although there are fewer complications and satisfactory repair appearance, the autologous cranial bone group needs to be operated again to increase the patient’s pain, and there is the disadvantage that the cranial bone becomes small and even necrotic and loosens after repair, and the fixation is unstable. At present, only very few hospitals perform this type of surgery.
Preoperative preparation for skull repair
All patients had no contraindications to surgery, and all of them underwent cranial CT and frontal bone X-ray examination. The digital molding group routinely performed a thin layer CT scan with a layer thickness of 2 mm and a three-dimensional reconstruction of the frontal bone, and then used the “titanium mesh digital molding machine” to mold and process the titanium mesh to produce a personalized titanium mesh restoration that was identical to the patient’s frontal bone defect and sterilized for backup; the time was about 3 working days.
Cranial repair surgery method
All patients were extubated under general anesthesia and the repair was performed by the overlay method. The repair was fixed with matching self-tapping titanium nails; antibiotics were routinely applied to prevent infection, the drainage tube was removed in 1 to 2 days, and the stitches were removed in 10 to 12 days.
Criteria for judging the efficacy of skull repair
Short-term postoperative observation of wound healing, plastic effect and complications, and final assessment of efficacy after 3 months of follow-up according to the following criteria
1.Excellent: reliable fixation of titanium alloy mesh plate, beautiful appearance, no complications after surgery;
2.Good: reliable fixation of titanium alloy mesh plate, postoperative complications improved after symptomatic treatment;
3.Poor: titanium alloy mesh slipped and displaced, or the titanium alloy mesh was removed due to other surgical complications.