|Year : 2020 | Volume
| Issue : 3 | Page : 513-521
Recent evaluation of decompressive craniectomy in severe traumatic brain injuries
Mohamed A Ellabbad, Usama M El Shokhaiby, Amr M Abd El-Aziz
Neurosurgery Department, Al-Azhar University Hospitals, Cairo; Damanhur Medical National Institute, Damanhur, Egypt
|Date of Submission||09-Apr-2019|
|Date of Decision||02-May-2019|
|Date of Acceptance||04-Sep-2019|
|Date of Web Publication||2-Oct-2020|
Amr M Abd El-Aziz
Neurosurgery Department, Al-Azhar University Hospitals, Damanhur Medical National Institute, Damanhour, Beheira, Cairo
Source of Support: None, Conflict of Interest: None
Background An injury to the brain or intracranial hemorrhage may cause it to swell. The pressure within the skull then increases as the brain has no room to expand; this excess pressure, known as intracranial hypertension, can cause further brain injury. High intracranial pressure (ICP) is the most frequent cause of death and disability in brain-injured patients. If high ICP cannot be controlled using general or first-line therapeutic measures such as adjusting body temperature or carbon dioxide levels in the blood and sedation, second-line treatments are initiated. One of these is a procedure called decompressive craniectomy (DC). DC involves the removal of a section of skull so that the brain has room to expand and the pressure decreases.
Patients and methods We studied 20 patients who presented to the Neuroemergency Unit in AL-Azhar University Hospitals in Cairo and Damanhur Medical National Institute in Damanhur from January 2017 to December 2017 with severe traumatic brain injury with clinical and radiological evidence of increased ICP and indicated for DC. All patients were followed up postoperatively in ICU with serial follow-up computed tomography. Consciousness level was evaluated using the Glasgow Coma Scale and Glasgow outcome score.
Results The overall mortality was five (25%) cases, four severely disabled (20%), and 11 (55%) patients had favorable outcome.
Conclusion In 20 cases with severely raised ICP resistant to conservative management, DC allowed 55% of cases to be discharged from hospitals with mild degree of disability for rehabilitation.
Keywords: decompressive craniectomy, intracranial pressure, traumatic brain injury
|How to cite this article:|
Ellabbad MA, El Shokhaiby UM, Abd El-Aziz AM. Recent evaluation of decompressive craniectomy in severe traumatic brain injuries. Sci J Al-Azhar Med Fac Girls 2020;4:513-21
|How to cite this URL:|
Ellabbad MA, El Shokhaiby UM, Abd El-Aziz AM. Recent evaluation of decompressive craniectomy in severe traumatic brain injuries. Sci J Al-Azhar Med Fac Girls [serial online] 2020 [cited 2020 Oct 26];4:513-21. Available from: http://www.sjamf.eg.net/text.asp?2020/4/3/513/296936
| Introduction|| |
Decompressive craniectomy (DC) is a surgical procedure in which a large section of the skull is temporary removed and the underlying dura mater is opened for the relief of high intracranial pressure (ICP) . This can be achieved by removal of fronto-temporal-occipital bone over one or both cranial hemispheres or can involve a bi-lateral removal .
High ICP within the fixed-volume skull, resulting from cerebral edema, intracranial hemorrhage, or a space occupying hematoma can quickly lead to secondary brain damage, herniation, permanent neurological damage, or death. DC effectively increases the volume that the brain can occupy under the scalp and may minimize ischemic damage by allowing increased cerebral blood flow and tissue oxygenation .
DC has been described in many studies as a life-saving intervention, which consistently decreases mortality and can often improve outcomes, especially when performed early in the course of the disease .
Intracranial hypertension (ICH) is a major cause of secondary brain injury. According to Monro–Kellie doctrine, ‘the sum of the intracranial volumes of blood, brain, cerebrospinal fluid and other components is constant and that an increase in any one of these must be offset by an equal decrease in another’ .
The use of DC to control ICP has been advocated for a number of disease processes, including stroke, tumors, and trauma. The rationale for DC is to prevent secondary injury caused by ICH .
The removed bone flap should be stored either frozen in a bone bank or in a subcutaneous pocket in the anterior abdominal wall. When frozen, bone flaps are wrapped in a sterile plastic container, transferred to the bone bank, and frozen at −80°C. However, bone banks are not available everywhere, especially in developing countries, and using the patient’s body to store the flap might be the only option. There are also complications that are specific to the cranioplasty surgery, including bone resorption , osteomyelitis , and hypovascular bone necrosis . Recent reports have suggested that earlier replacement of the bone flap, at 5–8 weeks instead of the more conventional 2–3 months, can reverse some of the common recovery symptoms and even create a better overall functional outcome .
Although this surgical procedure does not have any effect on primary brain damage, it can reduce the deleterious consequences of secondary lesions, such as the elevation of ICP and cerebral displacements or distortions .
The study aims to re-evaluate retrospectively and prospectively patients with severe head injuries exposed to surgical DC to alleviate increased ICH not responsive to medical and intensive care management and review the efficacy of the DC procedure on the postoperative clinical state of these patients.
Historical uses of decompressive craniectomy
The surgical removal of a portion of the skull, either for medical or superstitious reasons, is known in the anthropological context as ‘trepanation’. This commonly involved the drilling or scraping of a hole into the skull. Evidence of the most primitive craniectomy has been found in skeletons up to 6000 years old, with well-documented archaeological findings spread from pre-Columbian Peru to bronze-age Europe and Neolithic Africa .
In the late 1800s, the French physician and surgeon Paul Broca became intensely interested in the subject of primitive trepanation; he controversially theorized that this peculiar ancient practice was the earliest evidence of a surgical treatment for the buildup of ICP . There is a broad speculation as to the reasons that ancient practitioners removed skull portions on living subjects, but the logic in the observed modern cases argues that opening a hole in the skull creates a way of escape for the demons or spirits possessing an ailing person .
| Patients and methods|| |
Type of study
This is a prospective retrospective clinical study for evaluating the clinical outcomes of surgical DC in patients nonresponsive clinically to medical treatment.
The study includes 20 patients with severe head injury operated for DC from January 2017 to December 2017 in Egypt in Neurosurgery Department in Al-Azhar University Hospitals in Cairo and Damanhur Medical National Institute in Damanhur.
The following were the exclusion criteria:
- Nontraumatic causes of increased ICP,
- surgically unfit patients, and
- brain stem dead patients on admission.
Classifications of disabilities
According to Karnofsky performance status scale, patients were classified as to their functional impairment . This can be used to compare effectiveness of different therapies and to assess the prognosis in individual patients. The lower the Karnofsky score, the worse the survival of the patients. [Inline 1]
History was taken from the witnesses including the following:
- Age and sex.
- Mechanism of injury.
- Time of trauma.
- Time of loss of consciousness, and presence of lucid interval.
- Prehospital post-traumatic fits.
- General examination:
- It was aimed to exclude other extracranial injuries; all patients were subjected to chest, abdominal, orthopedic, and other assessments.
- Neurological examination:
- All patients were assessed clinically according to the Glasgow Coma Scale (GCS) score . Moreover, detection of the signs of lateralization was a main goal in addition to assessment of brain stem functions. This assessment includes the evaluation of pupillary reflex, corneal reflex, gag/cough reflex, oculocephalic reflex, vestibuloocular reflex, and spontaneous breathing. Pupillary asymmetry or anisocoria of more than 1 mm (≤1 mm may be physiological) must be attributed to an intracranial lesion until proven otherwise .
The patients with severe head trauma are the target of this study. Patients with head trauma are classified into mild, moderate, and severe traumatic brain injury according to the following classification . [Inline 2]
Laboratory investigations included the following:
- Complete blood count.
- Coagulation profile.
- Liver functions.
- Kidney functions.
Radiological investigations included the following:
- Computed tomography (CT) brain at time of presentation, on clinical deterioration, and postoperatively within 48 h.
CT scans aid in the examination of the bone windows for fractures and examination of the tissue windows for the presence of extra-axial hematoma, intraparenchymal hematomas, or contusions. CT scans also survey the brain for any evidence of pneumocephalus, hydrocephalus, cerebral edema, and midline shift.
- Serial follow-up CT brain was done till the patient was discharged or died.
Treatment strategy is surgical intervention after failure of medical treatment with postoperative continuity of brain relaxing intensive care treatment.
The study evaluated preoperative status, surgical technique, and outcome of surgical DC.
- Postoperatively patients were admitted to the ICU and had at least one CT scan performed within 72 h after operation. All survivors were followed up after operation with CT scan and neurological examination including GCS till the patients are discharged from the hospital.
- They were assessed by the GCS, and the outcome was graded using the Glasgow outcome score (GOS), which is defined as follows:
- Grade I as death.
- Grade II as persistent vegetative state.
- Grade III as severe disability (being conscious but disabled).
- Grade IV as moderate disability (being disabled but independent).
- Grade V as good recovery.
- Unfavorable outcome was defined as GOS 1–3 and favorable outcome as GOS 4 and 5 .
Surgical technique used in our cases
The patient is placed in supine position with head tilted to the other side of the pathology. The ideal sagittal angle of head is 0°–15° horizontal to the floor ([Figure 1]) .
The surgical procedure was performed as follows:
A large reverse question mark-shape incision is made from the midline anterior to the coronal suture, posterior several centimeters behind the ear, and to the root of the zygoma. The incision is performed ∼2 cm lateral to the midline for preventing damage to superior sagittal sinus.
Once the skin incision is made, usually with a no. 10 blade, the periosteum can be incised with an electrocautery knife. The cutaneous flap can then be manually reflected anteriorly with the aid of a surgical sponge.
At this point, there are two options for reflecting the temporalis muscle:
- The first option allows the skin to be reflected anteriorly as a separate layer of muscle. This maneuver allows the temporalis muscle to be reflected with relative ease.
- The second option involves reflecting the muscular and cutaneous flaps together; the skin flap is not separated from the temporalis muscle. The advantage of this option is that the muscle remains attached to the overlying scalp, keeping the muscle in position in the absence of an underlying attachment to the bone. This option is preferred because it preserves the muscle and improves cosmetic when the bone flap is returned (was done in most of our cases).
The bone flap is more than 15 cm in anteroposterior diameter and extends down toward the floor of the temporal fossa to provide adequate decompression .
The location and number of burr holes depends on the preference of the surgeon, but typically four holes are used: (a) temporal squama, (b) parietal area just posterior to the parietal bone and close to the skin incision, (c) frontal area 2 cm in front of the coronal suture and close to the skin incision, and (d) keyhole area behind the zygomatic arch of the frontal bone ([Figure 2]) .
|Figure 2 Unilateral frontotemporoparietal craniectomy: (a) frontal area 2 cm in front of the coronal suture and close to the skin incision. (b) Parietal area just posterior to the parietal bone and close to the skin incision. (c) Temporal squama. (d) Keyhole area behind the zygomatic arch of the frontal bone.|
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The bone flap is turned by extending the beginning of the craniectomy along the line toward the inion. To avoid injuring the transverse sinus, it is best to stay at least 1-cm rostral to the asterion. As the bone flap is extended posteriorly, the lambdoid suture is crossed. At this point, the drill bit is turned parallel to and 1-cm medial to the lambdoid suture until we reach a point 1 cm from the midline. The drill is then turned parallel to the sagittal sinus, again crossing the lambdoid suture. Drilling continues toward the supraorbital bar.
The craniotomy is continued anteriorly by hugging the floor of the frontal fossa as closely as possible, staying as close to the orbital rim as the anatomy allows. Next, the drill is turned posterolateral toward the keyhole and aimed as close to the pterion as possible. At this point, the drill is removed and re-inserted into the burr hole at the root of the zygoma. The second drill line is created by hugging the floor of the temporal fossa and extending it as far anteriorly as possible toward the temporal tip.
The bone flap is removed by levering it using the pterion as fulcrum. Usually the pterion cracks on removal, and the dura can be dissected using Rhoton dissector.
We ensure that the bone edges are smooth so the brain does not catch on an edge as it swells laterally. The midline delineates the course of the superior sagittal sinus.
The dura is opened in a C-shaped fashion from the temporal tip to the frontal pole. To maximize the opening, the dural incision is being within 1 cm of the bony edge. Thus, the dural flap is based on the pterion and can be reflected anteriorly to expose the hemisphere. At this point, the underlying hematoma can be evacuated (in case of haematoma). The source of bleeding is identified and controlled, and bridging veins are assessed to ensure that they are no longer bleeding.
Technique of duroplasty
Once hemostasis is ensured, the dura can be laid back on the brain.
Dural closure is recommended because of the following reasons:
- To keep postoperative extradural bleeding out of the subarachnoid space.
- To decrease the possibilities of formation of cortical adhesions to the soft tissues.
- To reduce the possibilities of occurrence of cerebrospinal fluid fistulae or leaks.
- To lessen the occurrence of intracranial infection, which when potentially present will be more likely isolated in the extradural space.
- To help prevent brain herniation from craniectomy sites across the bony edges, even when a graft is used .
Figure 3 presents one of our cases (intraoperative) ([Figure 4],[Figure 5],[Figure 6]).
|Figure 3 (a) Scope of craniectomy with bluish dura owing to acute subdural hematoma. (b) Shape of bone flap after removal. (c) During subdural hematoma evacuation (dura opened in C-shaped fashion). (d) After duroplasty.|
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|Figure 4 Chart showing relation between preoperative Glasgow Coma Scale and outcome.|
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|Figure 5 Chart showing male and female distribution in TBI. TBI, traumatic brain injuries.|
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| Results|| |
The data were collected from 20 cases of acute traumatic brain injury that were operated for DC aiming to decrease raised ICP. The study included 17 males and three females. Their age ranges between 4 and 66 years. There was a trend of increasing mortality associated with age ([Table 1],[Table 2],[Table 3],[Table 4],[Table 5]).
|Table 3 Relation between time from injury to surgical interference and outcome|
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| Discussion|| |
DC can be defined as the removal of a large area of skull to increase the potential volume of the cranial cavity. At the beginning of the last century, Kocher asserted that ‘if there is no cerebrospinal fluid pressure, but brain pressure exists, then pressure relief must be achieved by opening the skull’.
The incidence of traumatic brain injuries (TBI) is much more common in males than females. In this study, 17 males and three females.
The study done by Das et al.  included 20 patients with severe traumatic brain injury in whom DCs were performed between the periods of January 2010 and December 2012. Among these 20 patients, 15 were male and five were female, with male: female ratio of 3 : 1.
There was no significant difference in the prognosis between males and females in spite of male predominance.
Regarding mechanism of injury
Motor vehicle accidents are the leading cause of TBI-related mortality, which is highest in adults aged 20–24 years .
In our study, motor vehicle accidents were seen in 11 (55%) cases, fall from height in eight (40%) cases, and physical assault in one (5%) case.
In the study done by Das et al.  on 20 patients, the causes of severe traumatic brain injury were motor vehicle accident (including motorcycle) in 14 (70%), physical assault in four (20%), and fall from height in two (10%) cases.
Regarding time from injury to surgical intervention
Timing of DC remains a matter of controversy. Its purpose as a primary procedure is first the universally accepted indication of surgical evacuation of extra-axial hematoma, but it is also performed to relieve the pressure effect of brain contusion or edema, and to drain cerebrospinal fluid .
Clinical studies support the safety and effectiveness of DC as a primary surgical procedure for these indications. Multiple recent studies including the present study report good outcomes and reduced mortality when DC is performed early following TBI ,.
The application of DC as a secondary procedure to control ICH when medical management fails also has provoked dissent . When used as rescue therapy, outcomes have been predictably worse.
More accurately, secondary DC is employed as a component of a tiered therapeutic protocol as a neuroprotective strategy rather than as a salvage procedure .
In this study, the mortality rate in less than 2 h group was 0%, and 0% in the 2–4 h group, and 5% in the 4–6 h group, and 25% in those more than 6 h group.
In the study done by Seelig et al. , 82 patients had acute subdural hemorrhage (ASDH) after TBI; all were treated by DC. In the first 4 h, the mortality was 30 and 90% in those who had surgery after 4 h from injury.
Regarding associated injuries
Overall, 50% of patients had associated injuries (mainly orthopedic). This may be attributed to the more severe injuries the patient was subjected to in our study and the delay of arrival to hospital (50% admitted after 4 h from trauma) owing to traffic jams and lack of large neuro-trauma centers for referral.
Regarding the prognostic factors in this study
The factors affecting the prognosis of the patients were assessed as follows:
- Age: significant higher mortality is found in patients older than 50 years.
- Sex: in spite of a male predominance, there was no significant difference in the prognosis between males and females.
The incidence of TBI is more common in younger age groups (15–45 years). In our study, we found that 70% of patients were in this age group.Our study also revealed that earlier age group has better GOS than the latter age group.
Gower et al.  conducted a prospective single-centre study with strict exclusion criteria (based on patient’s age, radiological degree of injury, presence of brain stem injury, etc.) and found that ‘recovery was surprisingly good in earlier age group’, with only 8% of patients having unfavorable outcome.
Regarding the Glasgow outcome scale
GOS is classified as follows in this study: grade I as death (25%); grade II as persistent vegetative state (0%); grade III as severe disability, being conscious but disabled (20%); grade IV as moderate disability, being disabled but independent (40%); and grade V as good recovery (15%).
The study done by Hamel et al.  was conducted on 60 patients after TBI, who were operated upon by DC. Regarding the GOS, in that study, grade I was seen in 28.3%, grades II and III in 21.7%, and grades IV and V in 50%); however, in our study, grade I was seen in 25%, grade III in 20%, and grades IV and V in 55%.
In the study done by Das et al. , six (30%) patients had unfavourable outcome and nine (45%) had favourable outcome.
In the study done by Grindlinger et al. , which was a retrospective observational study on 31 patient aged 16–70 who were managed by unilateral DC during the time period January 2010 to September 2015, 22 of 31 (71%) patients had a good to moderate outcome, six of 31 (19%) had a poor neurological outcome, and two (6%) patients died.
This study had some limitations. The most obvious is the lack of any nonoperative-treatment group with which to compare the results and the small group of patients. However, conservative treatment would often be hard to justify, considering the poor clinical condition of the patients already receiving maximal medical therapy, and on the contrary, knowing that DC often normalizes increased ICP, which is the standard goal in modern neurointensive care. Moreover, there was a lack of ICP monitoring devices (e.g. miniature strain-gauge or fiber-optic transducers) to evaluate the relief of elevated ICP after surgery, which was judged upon only radiologically.
In addition, the follow up period is short and analysis of rehabilitation requires long follow up more than 6 months at least to be included in the final judgment regarding comparison of these surgical techniques.
| Conclusion|| |
We concluded that DC is the ideal solution for the management of acute TBI with persistent increased ICP when the other medical management options failed.
DC operation showed better outcome and reduced mortality when it is performed early following TBI.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]