Decompressive hemicraniectomy in malignant middle cerebral artery infarction: an analysis of long-term outcome and factors in patient selection §ASHOK PILLAI, M.D.,1 SAJESH K. MENON, M.CH.,1 SATYENDRA KUMAR, M.CH.,KARIYATTIL RAJEEV, M.CH.,1 ANAND KUMAR, D.M.,1 AND DILIP PANIKAR, M.CH.1 §Departments of 1Neurosurgery and 2Neurology, Amrita Institute of Medical Sciences, Amrita Vishwa, Vidyapeetham University, Kochi, Kerala, India § § J Neurosurg 106:59–65, 2007
Object. § Middle cerebral artery infarction often occurs at a younger age than other strokes and is associated with significant rates of mortality and morbidity §Approximately 10 to 20% of these infarctions are massive and cause severe brain edema resulting in uncal herniation and death. §These pathological entities have been referred to as “malignant MCA §The outcome in such cases with the best medical management (osmotic agents to reduce edema and mechanical ventilation to control the ICP )alone is generally poor—only 20 to 40% survival at best and a high degree of functional dependence in the survivors.
§Decompressive hemicraniectomy has been reported to immediately effect a dramatic reduction in ICP to normal ranges, preventing fatal uncal herniation and generally leading to a more rapid neurological recovery. It helps shorten the ICU stay, thus reducing medical complications §previous studies have already demonstrated improved outcomes in surgically treated patients compared with medically treated controls
§ Several large randomized controlled trials are ongoing. § Questions that remain unanswered include the following: §1) which subset of patients will benefit maximally? §2) which patients will survive with an unacceptable degree of functional dependency?; § 3)what is the optimal timing of surgery?
§The objectives of the present prospective nonrandomized study were as follows: § 1) to help better define the selection criteria for surgery §2) to assess the immediate outcome in terms of time to conscious recovery and survival; §3) to assess long-term outcome using standard QOL and functional assessment scales.
Clinical Material and Methods §Selection Process and Inclusion Criteria §Patients presenting with acute MCA infarction to the Amrita Institute of Medical Science, a tertiary care university teaching hospital, during the period between August 2001 and September 2004 §. An institutional protocol was formed with inclusion criteria (Patients with both dominant- and nondominant-hemisphere infarcts satisfying the CT criteria but not yet showing clinical signs of deterioration were admitted to the stroke unit and underwent surgery
Medical Management § treated with osmotic therapy (20% mannitol 0.5-g/kg bolus followed by 0.25–0.5 g/kg every 4–6 hrs, furosemide 10–20 mg every 4–6 hrs).
Surgical Procedure §A large frontoparietotemporal curvilinear incision, including the frontal, parietal, and temporal squamous bone, was removed. §The temporal squama was removed to the middle cranial fossa floor to reduce the chance of subsequent uncal herniation. §A curvilinear dural incision §No brain parenchyma was resected. §A duraplasty was performed using pericranium and temporalis fascia.
Outcome Analyses and Long-Term Follow Up §The immediate outcome measures included the number of days to conscious recovery (assessed by spontaneous eye-opening and localizing motor score), the number of days of ventilation, and the duration of the ICU stay. §long-term follow up was maintained through regular outpatient clinic visits. At each visit the patients were assessed using the NIHSS, BI, GOS, and the FIM walking score.
Outcome Analyses and Long-Term Follow Up To further assess the QOL, a subjective retrospective reconsideration questionnaire was sent to all survivors. On this questionnaire, the patient (if possible) and the relative involved in the most caregiving (generally a spouse, parent, or child of the patient) were asked the question “If you were faced with a similar situation in the future for yourself or someone close to you, would you again make the same decision?” The answer was recorded using a five-point scale (1 = definitely no, 5 = definitely yes).
BI = Barthel Index 巴士量表 NIHSS = National Institutes of Health Stroke Scale 美國國家衛生研究院腦中風評估量表 FIM = Functional Independence Measure. 功能獨立量表 GOS = Glasgow Outcome Scale; QOL = quality of life
Results Study Population § 26 patients (22 men and 4 women) §The mean patient age was 48.4 ± 11.2 years (range 28–66 years) with a normal distribution. §The mean GCS score was 9.9 ±3.2 §the mean NIHSS score was 17.7 ± 4.1. §The median time from ictus to surgery was 54 hours (range 13–288 hours).
Immediate Postoperative Outcome §The mortality rate in the 1st postoperative month was 28% (seven of 25 patients, one was lost to follow up). §There were no deaths after this period. §The median ICU stay was 5 ± 4.1 days, §The mean period of mechanical ventilation was 4.5 ± 1.9 days.
Long-Term Outcome Measures §survivors (19 patients), 17 (89%) were evaluated at 6 months and 18 (95%) were reviewed at 1 year.
Glasgow Outcome Scale §at 1 year postsurgery §60% of survivors had a good outcome (GOS Scores 4 and 5) §12% were severely disabled (GOS Score 3). §28%(7 patient) GOS 1
Barthel Index §23.5% functionally independent(BI >95)(At 6 months) - 33.3% (at 1 year) §64.7% partially dependent (BI 60–95)(At 6 months)- 55.6% ( at 1 year) §11.7% of patients were functionally dependent(At 6 months) § Among the functionally independent, four patients (22%) were eventually able to resume their previous employment §No patient was in a vegetative state.
National Institutes of Health Stroke Scale §At 1 year §92.9% had mild deficits (NIHSS Score 0–7), §7.14% had moderate deficits (NIHSS Score8–14) § no patients had severe deficits (NIHSS Score < 15).
Functional Independence Measure Walking Score §52.9% (9 patient) walking independently (Scores 6 and 7) (6m). 72%( 13patients)1year §Three patients (17%) required minimal assistance in walking (Score 4–5 §Two patients (11%) remained immobile at 1 year postsurgery.
Statistical Correlations §There was no statistically significant association between the time from infarct to surgery and the outcome measures (GOS, NIHSS, and BI) at 6 months or 1 year postsurgery §There was no statistically significant even when divided into categories based on early (# 48 hours from ictus) compared with late surgery (. 48 hours from ictus).
§A statistically significant negative correlation (r = 20.47) existed between patient age and the BI (p = 0.048, Pearson test) at 1 year postsurgery,although this correlation was not present at 6 months posttreatment (p = 0.071). §There was a similar negative correlation between patient age and the FIM walking score at 1 year posttreatment (r = 20.54, p = 0.020, Pearson coefficient) §Death was not related to patient age
§The variables subjected to univariate analysis were age, all medical comorbidities, preoperative stroke severity based on the GCS and NIHSS, time from infarct to surgery, and pupil asymmetry. § Only the laterality of the stroke and the presence of preexisting hypertension were significant predictors of high mortality rate on univariate analysis. §On multivariate analysis, however, only hypertension was found as a statistically significant predictor of death and stroke laterality was no longer significant (p = 0.08). §Note, however, that the study was limited in this respect given its small sample size.
Subjective Reconsideration §Retrospective reconsideration data were available for 14 (74%) of the 19 survivors. The mean score was 4.4 ± 1.2(4 = probably yes, 5 = definitely yes). When an outlying point (that from a 65-year-old patient who died after 21 months) was removed, we observed a significant downward trend (r = 20.61, p = 0.028, Spearman correlation) in the reconsideration score over time
Discussion §Several other investigators reporting poor outcome in patients at various stages of herniation or operate on an older population. §A higher chance of a vegetative outcome when surgery is performed in the late stages of herniation has been reported.
§Several previously reported studies have shown an improved outcome when surgery is undertaken earlier in the course of neurological deterioration. § Our study data failed to demonstrate a direct correlation between clinical outcome and timing of surgery from the acute onset of symptoms due to ischemia.
§Based on our data and that from the available literature, we propose that younger patients with infarcts in the nondominant hemisphere are likely to benefit significantly and thus should undergo surgery. § Although patients with dominant hemisphere infarcts are likely to survive with more disabling deficits, surgery can be undertaken with the hope of reducing the hospital stay and rates of morbidity and mortality.
§Severe brain edema causes a regional increase in ICP, further reducing the regional cerebral perfusion pressure and cerebral blood flow, which may potentiate further infarction and thus create a vicious cycle §Decompressive hemicraniectomy probably helps to break this cycle.
§other case series have reported on the removal of edematous temporal lobe to achieve further reduction in ICP and prevent herniation §With the possible exception of hemispheric infarcts involving all three arterial territories, we found that this step was generally not necessary. A temporal osseous decompression should probably allow for the same effect.
Quality of Life Issues §The unresolved controversy of whether to perform decompressive hemicraniectomy centers on the issue of QOL among the survivors. §This study and several others have demonstrated an acceptable functional outcome after surgery
Quality of Life Issues §Specifically, there were no survivors in a vegetative state in our series of patients. §Other reported have also demonstrated that a vegetative outcome occurs much less with surgery §It was eventually possible to achieve a near-normal QOL in 22% of the survivors at 6 months
§ However, the psychological impact and practical difficulties created by major deficits such as motor aphasia and limb paresis preventing employment and resumption of previous activities were significant. § The downward trend in the retrospective reconsideration score over time could indicate that these long-term difficulties make patients and their caretakers eventually doubt whether their choice of a life-saving intervention was for the best.
Conclusions §The fact remains that malignant MCA infarction implies some amount of long-term disability despite the best management. §Perhaps new developments in restorative therapy can be combined in the future to reduce the burden of this disabling condition. §We hope that our findings will add to existing information on decompressive hemicraniectomy to serve as guidelines until further data are available from the ongoing randomized control trials.