Although there is convincing evidence that decompressive craniectomy can significantly reduce mortality rate and improve neurological outcome in young patients (<60 years) 1) , many surgeons are still hesitant to recommend hemicraniectomy for stroke patients.
DC improves cerebral hemodynamics in patients with malignant middle cerebral artery infarction, and the level of improvement is related to outcome. However, some patients did not seem to experience any additional hemodynamic benefit, suggesting that perfusion CT may play a role as a prognostic tool in patients undergoing DC after ischemic stroke 2). Decompressive hemicraniectomy (DH) in malignant middle cerebral artery infarction reduces mortality significantly but evidence for long-term functional benefit is sparse and contradictory.
Several large, randomized trials in malignant middle cerebral artery infarction have firmly established the benefit of decompressive hemicraniectomy (DHC) as a treatment of malignant middle cerebral artery territory infarction (MMI). Further studies since then have not only better characterized the diagnosis and predictors of MMI, but have also shown that this benefit extends to patients with additional clinical and demographic characteristics. Future randomized studies should continue to evaluate the benefit of a DHC in other subgroups, and assess neurocognitive and psychosocial secondary outcomes 3).
In a nationwide survey of decompressive hemicraniectomy for malignant middle cerebral artery infarction in Japan, less than one-tenth of candidates with malignant MCA infarction in Japan underwent decompressive surgery, and the vast majority of patients were elderly. Age was not found to be an independent factor for immediate mortality in this study, and performing surgery in the elderly may be justified based on additional evidence of functional improvements 4).
Rai et al., conclude that DH in malignant MCA infarction not only reduces mortality but also increases chances of a better functional outcome. The benefit of surgery in motor and aphasia recovery is progressive and sustained until 1 year 5).
According to the current literature, decompression craniectomy in older patients can increase survival without most severe disabilities, although, most survivors need assistance in most bodily needs. Involvement of the dominant hemisphere results in aphasia that might partly recover in younger patients, although, considering the neuropsychological deficits caused by infarctions of the nondominant hemisphere, involvement of the dominant hemisphere does not pose as a contraindication for decompression craniectomy. Furthermore, there is convincing evidence that surgery should be performed within 48 h after the onset of symptoms and the size of the craniectomy should be at least 12 cm as a minimum. An additional lobectomy or the resection of the temporal muscle, however, can only be part of individual treatment options. Conceding the weak evidence, it is recommended to close the dura by some form of a duraplasty avoiding cerebrospinal fluid leakages or scarring between the cortex and the scalp leading to injuries during reimplantation of the bone-flap. Complications associated with decompression surgery (hemorrhages, infections, ‘sinking skin-flap syndrome’, cerebrospinal fluid leakages, hydrocephalus, seizures), with the infarction itself, or with those that occur during the ICU course (cardiac and pulmonary complications) appear acceptable and are mostly treatable, especially considering the fatal course of conservative treatment. Key Message: This review summarizes the current state of the literature about decompression craniectomy of patients with malignant stroke addressing, in particular, critical surgical issues, and thus, help surgeons to make decisions confidently for/or against performing surgery 6).
Nevertheless, pressing issues persist that need to be answered in future clinical trials, e.g. the acceptable degree of disability in survivors of malignant middle cerebral artery infarction, the importance of aphasia, and the best timing for decompressive hemicraniectomy 7). 8).
The mortality rate of patients with brain edema after malignant middle cerebral artery infarctionapproaches 80 % without surgical intervention. Surgical treatment with ipsilateral decompressive hemicraniectomy (DHC) has been shown to dramatically improve survival rates. DHC currently lacks established inclusion criteria and additional research is needed to assess the impact of prognostic factors on functional outcome.
According to PRISMA guidelines, Li et al from the Department of Neurosurgery, The Clinical Medical College of Yangzhou University, China searched databases containing articles published in English (MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) and Chinese (Chinese Biomedical Literature Database, China Science and Technology Journal Database, and China National Knowledge Infrastructure) for randomized controlled trials (RCTs) of decompressive hemicraniectomy published before January, 2016. They extracted data on patient characteristics, methodological quality, and outcome measures. The outcomes assessed included mortality and good functional outcome (GFO). We did a subgroup analysis to determine the effect of age and surgical timing on mortality and functional outcomes.
14 studies were included in this metaanalysis, including 830 patients with severe middle cerebral artery infarction. In the total population, mortality was lower in the decompressive hemicraniectomy group than in the conventional treatment group at 6 months after onset (odds ratio [OR] 0·19, 95% CI 0·11-0·33; p<0·0001), and at 12 months (OR 0·18, 0·11-0·28; p<0·0001). The pooled OR of GFO was 3·15 (95% CI 1·49-6·69; p=0·003) at 6 months, and 1·95 (1·19-3·19; p=0·008) at 12 months. Survival with moderately severe disability was higher in the decompressive hemicraniectomy group at 6 months (OR 3·90, 95% CI 2·23-6·83; p<0·0001) and 12 months (OR 4·36, 2·55-7·36; p<0·0001). However, with regard to survival with severe disability, no significant differences were observed (p=0·55 at 6 months, p=0·81 at 12 months). In the subgroup analysis, compared with conventional treatment, decompressive hemicraniectomy significantly decreased mortality in patients older than 60 years (p<0·0001) and 60 years or younger (p<0·0001). With regard to survival with moderately severe or severe disability, significant differences were observed between treatment groups both in patients older than 60 years (p=0·0002) and 60 years or younger (p=0·0002). No significant differences between treatment groups were found in the subgroup analysis of surgical timing.
Compared with conventional treatment, decompressive hemicraniectomy could significantly reduce mortality and improve prognosis both in patients older than 60 years and those aged 60 years or younger with severe middle cerebral artery infarction. However, compared with conventional treatment, more patients who receive decompressive hemicraniectomy might survive with moderately severe or severe disability 9).
Wang et al searched PUBMED, EMBASE and the Cochrane Central Register of Controlled Trials. Other sources, including internet-based clinical trial registries and grey literature, were also searched. After searching the literature, two investigators independently performed literature screening, assessing the quality of the included trials and extracting the data. The outcome measures included the composite outcome of death or dependence and the risk of death. Ten RCT were included: seven RCT were on malignant middle cerebral artery infarction (MCAI) and three were on severe traumatic brain injury (TBI). Decompressive craniectomy significantly reduced the risk of death for patients suffering malignant MCAI (risk ratio [RR] 0.46, 95% confidence interval [CI]: 0.36-0.59, P<0.00001) in comparison with no reduction in the risk of death for patients with severe TBI (RR: 0.83, 95% CI: 0.48-1.42, P=0.49). However, there was no significant difference in the composite risk of death or dependence at the final follow-up between the decompressive craniectomy group and the conservative treatment group for either malignant MCAI or severe TBI. The present meta-analysis indicates that decompressive craniectomy can significantly reduce the risk of death for patients with malignant MCAI, although no evidence demonstrates that decompressive craniectomy is associated with a reduced risk of death or dependence for TBI patients 10).
A retrospective cohort study was carried out including 46 patients who underwent DHC at the KarolinskaUniversity Hospital between 2004 and 2014. The maximum time to surgery was 5 days after symptom debut. The primary endpoint was a dichotomised score on the modified Rankin Scale (mRS) 3 months after surgery, with favourable outcome defined as mRS ≤ 4.
When the study population was dichotomised according to the primary endpoint, a significant difference between the groups was seen in preoperative Glasgow Coma Score (GCS), blood glucose levels and the infarction’s involvement of the basal ganglia (p < 0.05). In a logistic regression model, preoperative GCS contributed significantly with a 59.6 % increase in the probability of favourable outcome for each point gained in preoperative GCS (p = 0.035).
The results indicate that preoperative GCS, blood glucose and the infarction’s involvement of the basal ganglia are strong predictors of clinical outcome. These factors should be considered when assessing the probable outcome of DHC, and additional research based on these factors may contribute to improved inclusion criteria for DHC 11).
Antuña-Ramos et al. analysed 21 patients one year after malignant middle cerebral artery infarction who have undergone decompressive craniectomy determine the degree of retrospective satisfaction, they asked relatives and patients whether, now that the patient’s current sequelae are known, they would have still agreed to a decompressive craniectomy.
The physical sphere is felt to be more disrupted than that concerning emotional aspects. There are no differences in the quality of life between patients who have the right or the left hemisphere affected. Patients with a better functional situation report a better quality of life. Altogether, 81% of patients said they were satisfied.
Despite the fact that all the patients show a loss of quality of life after a decompressive craniectomy, most of them seem to be satisfied with the treatment they have received, even in cases in which the dominant hemisphere is compromised or in those with a moderate-severe disability 12).
The optimal timing of decompressive craniectomy in pediatric patients after presentation with malignant middle cerebral artery infarction is unknown. A previously healthy 6-year-old Japanese girl who had good outcome after emergency decompressive craniectomy 116 h after malignant middle cerebral artery infarction. This case suggests that the timing of decompressive craniectomy can be delayed until deterioration of neurological findings and, compared with adults, a more prolonged time course for surgical intervention might be acceptable 13).