Hiroyuki Masaoka’s research while affiliated with National Hospital Organization Nagoya Medical Center and other places

Objective: The effects of difference in the guiding system on the results of stent thrombectomy were investigated. Methods: Of the patients who underwent intracranial thrombectomy using a stent retriever in 2015 and 2016, those with lesions in the internal carotid artery (ICA) or the horizontal (M1) segment of the middle cerebral artery were divided into a group treated with a balloon guide catheter (BGC) alone and a group treated with a combination of BGC + distal access (aspiration) catheter (DAC), and 1) the time from puncture to recanalization, 2) number of passes, 3) frequency of occurrence of embolization to new/distal territory (ENT/EDT), and 4) percentage of complete recanalization were compared. Results: The subjects were 17 patients consisting of 6 in the BGC group and 11 in the BGC + DAC group. The results concerning the above items were 1) 80.0 vs. 46.7 min (p = 0.03), 2) 2.8 vs. 1.5 times (p = 0.03), 3) 50% vs. 0% (p = 0.03), and 4) 66.7% vs. 90.9% (p = 0.52), respectively. Conclusion: In the BGC + DAC group, the time until recanalization was shorter, the number of passes was fewer, and the frequency of ENT/EDT was lower, suggesting that more favorable results may be obtained by BGC + DAC.

Arteriovenous malformation (AVM)-related intracerebral hemorrhage (ICH) is the cause of approximately 2–3% of ICH and is an important factor in the significant morbidity and mortality in patients with AVM. Decompressive craniectomy (DC) is a surgical procedure to relieve malignant elevation of intracranial pressure. The use of DC to treat patients with AVM-ICH has been much less common. The present study describes our experience with DC for AVM-ICH and discusses the safety of this procedure. The present retrospective analysis compared 12 consecutive patients treated with DC for AVM-ICH with 23 patients treated with DC for hypertensive ICH. Nine patients were male and three were female, aged from 11 to 53 years (mean, 31.7 years). Hematoma volumes ranged from 50 to 106 ml (mean, 75.8 ml). The outcomes were good recovery in one patient, moderate disability in three, severe disability in seven, and vegetative state in one. Complications after DC included subdural hygroma in four patients, hydrocephalus in one, intracranial infection in two, and intracranial hemorrhage in one. No significant difference was found in the incidence of complications between DC for large AVM-ICH and DC for hypertensive ICH. In conclusion, the present study found no significant difference in the incidence of complications between DC for large AVM-ICH and DC for hypertensive ICH. Further investigations including a prospective randomized trial are needed to confirm the safety and efficacy of DC for the treatment of large AVM-ICH.

Numerous studies on hydrocephalus after decompressive craniectomy (DC) for severe traumatic brain injury have been reported, whereas there have been only two reports on DC for hemispheric cerebral infarction. Here, we present the clinical details of 23 patients who underwent DC for hemispheric cerebral infarction and the incidence of hydrocephalus following DC. Of the 23 patients, 13 were male and 10 were female, with an age range from 34 to 75 years (mean, 60.8 years). The areas of hemispheric infarctions were those of the middle cerebral arteries in 12 patients and of the internal carotid arteries in 11 patients. The mean preoperative GCS score was 6. Nineteen patients (82.6 %) underwent cranioplasty. Pre-cranioplasty hydrocephalus was observed in 11 (47.8 %) patients. Four patients who had precranioplasty hydrocephalus were transferred or died without cranioplasty, and post-cranioplasty hydrocephalus occurred in 7 (36.8 %). Only one patient underwent a shunt procedure after cranioplasty. We consider that the explanation for the discrepancies between our study and the previous studies might lie in the definition of hydrocephalus and the indications for shunting.

Twenty patients with traumatic basal ganglia hematoma (TBGH) were studied. Of the 20 patients, 16 were male and 4 were female, with an age range of 4–89 years (mean, 54.4 years). The causes of injury were traffic accidents in 12 patients and falls in 8. The mean admission GCS score was 7.5. Skull fractures were revealed in five patients (25 %). The hematoma was found in the putamen in 15 patients (80 %), the thalamus in 4, and the caudate in 1. The mean hematoma volume was 10.7 mL. The CT findings indicated focal contusions in 9 patients, subdural hematoma in 5, intraventricular hemorrhage in 4, subarachnoid hemorrhage in 10, and diffuse axonal injury in 5. Six patients (30 %) underwent surgery. The final outcomes were poor: 7 patients (35 %) died, 1 was in a vegetative state, 4 experienced severe disabilities, and 8 patients (40 %) made a favorable recovery. The statistical analysis identified the GCS score and midline shift as prognostic factors. Our study revealed interesting characteristics of TBGH, including a high frequency of putaminal involvement, a low frequency of skull fractures, a high frequency of associated intracranial lesions, and a high poor outcome and mortality rate.

Subacute subdural hematoma (SASDH) is a rare entity. We retrospectively reviewed 8 patients with SASDH. Four patients were male and 4 were female, with an age range of 45-87 years (mean, 67.8 years). The minimal level of deterioration ranged from 8 to 14 (mean, 10.5). The deterioration of neurological symptoms was confirmed 4-20 days after injury (mean, 12.9). The hematoma volume was increased in 6 patients. Seven patients underwent surgeries (burr-hole irrigation in 6, craniotomy in 1). The Glasgow Outcome Scale indicated a good recovery in 4 patients and moderate disability in 4 patients. Increased cerebral blood flow was observed just below the SDH in 1 patient. We consider that the hypoperfused tissue in the acute phase might become hyperperfused during the subacute phase owing to impaired autoregulation, and the hyperperfusion may be responsible for the development of the SASDH, leading to deterioration. Further investigations in a larger series are needed to elucidate the mechanism underlying the development of SASDH.

Posterior fossa injury is rare, occurring in less than 3 % of head injuries. We retrospectively reviewed patients' clinical and radiological findings, management, and outcomes. The aim of the present study was to investigate the features of posterior fossa hematoma, including posterior fossa epidural hematoma (EDH), posterior fossa subdural hematoma (SDH), and intracerebellar hematoma. From January 1995 to January 2009, 4,315 patients with head trauma were hospitalized at our institution. The -present study focused on 41 patients (1.0 %) with traumatic hematomas of the posterior fossa. Eighteen patients had EDH, 10 patients had SDH, and 17 patients had intracerebellar hematomas. In each type of injury, occipital bone fractures were seen in many patients, and hematoma enlargement was often observed within a few days of the injury. In addition, a high frequency of associated lesions and a high poor outcome rate were features of intracerebellar hematomas and -posterior fossa SDH. The present study suggests that repeat CT imaging and careful management are necessary until the lesion is stabilized, and patients showing lesions with mass effects should therefore be immediately treated with surgery.

New findings (NF) on postoperative CTs are -occasionally found in patients who undergo surgery for traumatic brain injury (TBI). We conducted a retrospective -registry-based review of the care of 102 patients who underwent decompressive craniectomy (DC) for TBI to investigate the prognostic factors of new findings on CT early after -surgery. Of the 102 patients, the mean age was 50 years and 69.6 % were male. The overall survival was 72.5 %. The primary indication for DC included subdural hematoma in 72 (70.6 %), epidural hematoma in 17 (16.7 %), and intraparenchymal contusion in 13 (12.7 %). New findings on postoperative CTs were observed in 26 patients (25.5 %). The univariate analysis showed that a GCS score ≤8 (P = 0.012) and the absence of a basal cistern (P = 0.012) were significantly associated with NF on postoperative CT. The logistic regression analysis demonstrated that the GCS score ≤8 (P = 0.041; OR, 3.0; 95 % CI, 1.048-8.517) was the only significant factor. TBI patients with a low GCS score who underwent DC should undergo additional CT evaluations immediately after surgery.

The aim of the present study was to investigate the risk factors for hydrocephalus after decompressive craniectomy (DC) for hemispheric cerebral infarction. This study selected 28 patients who underwent DC for malignant hemispheric cerebral infarction. The patients' clinical and radiologic findings were retrospectively reviewed. Fourteen of the 28 patients were male and 14 were female, with an age range from 34 to 80years (mean, 63.5years). Eighteen patients (64.3%) underwent DC within 48hours of stroke onset. The superior limit of DC was <25mm from the midline in 16 patients (57.1%). Twenty-two patients underwent cranioplasty, and the interval from DC to cranioplasty was within 60days in 14 patients. Pre- and post-cranioplasty hydrocephalus were observed in 13 and nine patients, respectively. Two patients required shunt procedures for post-cranioplasty hydrocephalus. Patients with DC whose superior limit was <25mm from the midline had a significantly increased risk of developing not only pre-cranioplasty but also post-cranioplasty hydrocephalus (p=0.008, p=0.010, respectively). In addition, the presence of pre-cranioplasty hydrocephalus was significantly associated with the development of post-cranioplasty hydrocephalus (p=0.001). The presence of pre- and post-cranioplasty hydrocephalus was significantly associated with a poor outcome (p=0.031, p=0.049, respectively). DC with a superior limit <25mm from the midline should be avoided to prevent the development of hydrocephalus.

Objective: Primary brainstem hemorrhage (PBH) frequently causes severe disturbances of consciousness, papillary abnormalities, as well as respiratory and motor disturbances. The prognosis has been reported to be highly dependent on the clinical severity at presentation and the presence of certain radiological markers. However, the number of PBH patients enrolled in previous reports tended to be small, and precise statistical analyses were also lacking. The aim of this study was to analyze the impact of clinical or radiologic parameters on the outcome of patients with PBH. Methods: We retrospectively reviewed 212 consecutive patients with PBH and analyzed the impact of the clinical or radiological parameters on the outcome of patients with PBH. Results: Of the 212 patients, 134 (63.2%) were male and 78 (36.8%) were female, with an age range of 17-97 years (mean, 60.3 years). The median admission GCS score was 4. The outcomes included a good recovery in 13 patients (6.1%), moderate disability in 27 (12.7%), severe disability in 27 (12.7%), a vegetative state in 23 (10.8%), and death in 122 (57.5%). A multivariate analysis demonstrated bilateral hematoma extension, a GCS score ≤8, the presence of hydrocephalus, gender, and the hematoma volume to all be significantly associated with the 3-month mortality, while the GCS score ≤8, the presence of a pupillary abnormality, and the hematoma volume were found to be associated with the 3-month poor outcome. Conclusion: The identification of these factors is therefore considered to be useful for managing patients with PBH.

Background: It is well known that intracranial lesions, which are already diagnosed on preoperative computed tomography, often expand after surgery, and the risk factors have been investigated. On the other hand, we have experienced cases in which new lesions, which were not detected on preoperative computed tomography, were found on postoperative computed tomography. However, little is known about the factors associated with such new postoperative lesions. Here, we investigated the predictive factors of new findings (NFs) on computed tomography early after surgery. Methods: We conducted a retrospective registry-based review of 186 consecutive patients who underwent surgery for traumatic brain injury and investigated the prognostic factors of NFs on computed tomography early after surgery. Results: Mean age was 51 years, and 67.2% were males among the 186 patients. NFs on postoperative computed tomography were observed in 29 patients (15.6%). A univariate analysis showed that Glasgow Coma Scale (GCS) score of 8 or less (p < 0.001), subdural hematoma as the primary indication for surgery (p = 0.012), midline shift (p < 0.001), absence of basal cistern (p < 0.001), and decompressive craniectomy and craniotomy as the surgical procedures (p < 0.001, p = 0.004, respectively) were significantly associated with NFs on postoperative computed tomography. A logistic regression analysis demonstrated that decompressive craniectomy as the surgical procedure (p = 0.001; odds ratio [OR], 8.1; 95% confidence interval [CI], 2.23-28.82), GCS score of 8 or less (p = 0.019; OR, 3.4; 95% CI, 1.23-9.52), and absence of basal cistern (p = 0.023; OR, 3.5; 95% CI, 1.19-10.35) were significant factors. Conclusion: Early postoperative computed tomography after surgery for head trauma seems to be warranted in patients presenting with the indicated predictive factors of NFs. Level of evidence: Prognostic/therapeutic study, level III.