RESUMEN
BACKGROUND: Decompressive craniectomy (DC) is a procedure performed increasingly often in current neurosurgical practice. Significant perioperative morbidity may be associated to this procedure because of the large skull defect; also, later closure of the skull defect (cranioplasty) may be associated to post-operative morbidity as much as any other reconstructive operation. The authors present a newly conceived/developed device: The "Skull Flap" (SF). This system, placed at the time of the craniectomy, offers the possibility to provide cranial reconstruction sparing patients a second operation. In other words, DC and cranioplasty essentially take place at the same time and in addition, patients retain their own bone flap. The current study conducted on animal models, represents the logical continuation of a prior recent study, realized on cadaver specimens, to assess the efficacy and safety of this recently developed device. MATERIALS AND METHODS: This is an experimental pilot study on dogs to assess both safety and efficacy of the SF device. Two groups of experimental raised intracranial pressure animal models underwent DC; in the first group of dogs, the bone flap was left in raised position above the skull defect using the SF device; on the second group the flap was discarded. All dogs underwent transcranial Doppler (TCD) to assess brain perfusion. Head computed tomography (CT) scan to determine flap position was also obtained in the group in which the SF device was placed. RESULTS: SF has proved to be a strong fixation device that allows satisfactory brain decompression by keeping the bone flap elevated from the swollen brain; later on, the SF allows cranial reconstruction in a simple way without requiring a second staged operation. In addition, it is relevant to note that brain perfusion was measured and found to be better in the group receiving the SF (while the flap being in a raised as well as in its natural position) comparing to the other group. CONCLUSION: The SF device has proved to be very easy to place, well-adaptable to a different type of flaps and ultimately very effective in maintaining satisfactory brain decompression and later on, making easy bone flap repositioning after brain swelling has subsided.
RESUMEN
OBJECTIVES: Transtentorial brain herniation is a major cause of morbidity and death following severe closed head injury. The purpose of this study was to evaluate the efficacy of selective uncoparahippocampectomy and tentorial splitting as an adjuvant method of treating otherwise uncontrollable elevated intracranial pressure (ICP) while attempting to prevent or minimize the devastating consequences caused by transtentorial herniation. METHODS: The authors retrospectively reviewed data from a series of 80 consecutive cases of severe closed head injury (Glasgow Coma Scale [GCS] score < 8) treated in their neurosurgical unit. All patients had elevated ICP and downward tentorial herniation, as documented with ICP monitoring, and clinical examination and computed tomography, respectively. Given the evidence of acute and ongoing neurological deterioration, all patients were treated with selective uncoparahippocampectomy and tentorial edge incision followed by wide decompressive craniectomy and duraplasty. RESULTS: All injuries were caused by blunt trauma with signs of acute and/or progressive increased ICP causing downward transtentorial herniation. Fifty-eight patients were male and 22 were female with a mean age of 35 years and a mean preoperative GCS score of 5. Based on the current American Association of Neurological Surgeons guidelines for head trauma, an intraparenchymal ICP device (Camino, Integra) was placed in all patients who had a GCS score < 8, and ICP was consistently > 20 cm H2O. Whenever possible, risks and benefits were explained to family members, and then surgery was performed within 3-16 hours (median 6 hours). At a mean follow-up of 30 months, the outcome was favorable (Glasgow Outcome Scale [GOS] score of 4 or 5) in 60 patients (75%) and unfavorable (GOS score of 3) in 8 (10%), whereas the remaining 12 patients (15%) died at some point during the postoperative course. There was no survivor patient in a vegetative state. A younger age had a significant effect on positive outcome (p < 0.0005), as did an earlier operation (p < 0.04). The preoperative neurological status as assessed using the GCS as well as pupillary reactivity had no significant effect on outcome (p = 0.054 and p > 0.05, respectively). CONCLUSIONS: A selective uncoparahippocampectomy with a tentorial edge incision and a wide decompressive craniectomy with duraplasty can be an effective adjuvant form of aggressive treatment to improve outcome in patients with severe closed head injury, especially in those who are younger if they are treated promptly.