To clarify the mechanism of chronic subdural hema­toma, the hematomas taken intraoperatively were mixed with the fresh patient’s blood and observed the clot formation. Forty–five patients who had undergone the surgery for chronic subdural hematoma were included in this study. The samples of 10 ml hematomas taken from subdural hematomas were divided into three groups; group A: the control group, group B: the group to which 0.1 ml of the patient’s own venous blood was added, and group C: the group to which 1 ml of the patient’s own venous blood was added. The patient’s venous blood was added immediately after the hematomas were taken. After 24 hours at room temperature, the amount of clots in each group were measured and examined. Clots were more like­ly to form in the group C. The amount of clots was greater in the patients with postoperative recur­rence. Increased fibrinolytic activity at the site of the hema­toma membrane has been reported to be involved in the patho­genesis of chronic subdural hematoma. On the other hand, just only hematomas were examined in this study, and fibrinolytic activity alleged to have in the hematoma membrane was not taken into consideration. However, it is suggested that in­creased coagulation activity in the hematoma mixed with the fresh blood by more than certain amount may be involved in the mechanisms of the recur­rence in chronic subdural hematoma.

Background: The purpose of this study was to clarify the criteria for initial treatment of chronic subdural hematoma (CSDH) by com­paring the backgrounds and post–treatment courses of patients who underwent drainage or middle meningeal artery (MMA) emboliza­tion for CSDH.

Methods: We performed a retrospective investigation of 23 and 21 patients who underwent drainage and MMA embolization, respec­tive­ly, performed between April 2020 and July 2022 as initial treatment for unilateral CSDH.

Results: There was no significant difference between the drainage and embolization groups in terms of age (78 vs 76 years), gender, lateral­ity of lesion, maximum diameter of hematoma (21 vs 19 mm), pretreatment Markwalder grading system (MGS) score (1 vs 1), or length of hospital stay (5 vs 17 days) between the groups. Pretreatment midline shift was greater in the drainage group than the MMA embolization group (8.8 vs 6.6 mm). Operative time was shorter in the drainage group (32 vs 79 min). Recurrence occurred in 2/23 (8.7%) of the drain­age group, in whom addi­tional MMA embo­lization was per­formed. Additional drainage was required due to exacerbation of symptoms in 4/21 (19%) of the MMA embo­lization group. No perioperative complications occurred in either group. There was no significant difference in median pre­operative MGS score (1 vs 1) or mean maximum hematoma diameter (18 vs 19 mm) in the 17 patients who showed resolution of CSDH by MMA embolization alone or in the 4 patients who required additional drain­age. Mean midline deviation was 6.1 and 8.9 mm in the embo­lization alone and additional drainage groups, respec­tively, and was significantly greater in those who required additional drainage (p=0.002).

Conclusions: The postoperative course between patients who under­went drainage or embolization for CSDH showed no significant difference in the case of very mild preoperative neurological findings (MGS score of about 1). Patient selection for MMA embolization as the initial treatment for CSDH should be clarified based on clinical symptoms and the radiological findings.

Although the surgical indication of acute subdural hematoma (ASDH) is described in guidelines, outcomes of initial conservative management have not been investigated in detail. The purpose of the present study was to clarify frequency and causes of neurological aggravation during initial conservative management for ASDH.

Patients with ASDH treated at the Akita University Hospital between April 2014 and September 2022 were reviewed retrospectively. Patients who received initial conservative management because of non–severe neurological deficits were divided into two groups; with or without fur­ther neurological aggravation. Risk factors, reasons of the aggrava­tion, treatment after the aggravation and clinical outcomes were analyzed.

In a total of 73 patients with ASDH, 58 (79.5%) patients were initially managed conservatively. Among 42 non–severe cases, 30 (71.4%) pa­tients had no further neurological aggravation. Twelve (28.6%) patients with neurological aggravation (between day 1 – 11) had significantly thicker initial ASDHs and lower Glasgow Coma Scales at discharge than those without aggravation. The causes of the aggravation included hematoma enlargement and seizure in 2 cases each, systemic complications in 1, and others in 7 cases. In the last 7 cases, hyperintensity lesions in the cerebral cortex adjacent to the hematoma on arterial spin labelling (ASL) images were observed in 6 cases and abnormal electro­encephalography (EEG) findings (spike–and–waves or slow waves) in 3 cases. In four of these 7 cases, hematoma removal was performed resulting in improving their clinical symptoms.

In conclusion, in patients with ASDH who were initially managed conservatively due to non–severe neurological deficits, further aggravation was observed in 12 (28.6%). Six (50.0%) of these showed ASL and/or EEG findings that may not contradict non–convulsive seizures. To clarify the causes of neurological aggravation during initial con­servative management more precisely, further investigation employing continuous EEG will be expected.

Chronic subdural hematoma (CSDH) sometimes occurs in patients with spontaneous intracranial hypotension (SIH). Conservative therapy including bed rest and hydration, should be initially considered when the patient does not present consciousness disturbance or paralysis. However, if the patient does not get improved by conservative thera­py alone, the treatment strategies for these cases remain controversial.

We herein report two cases of bilateral CSDH concomitant with SIH, which were successfully treated by epidural blood patch (EBP) for SIH followed by burr hole evacuation for CSDH within a day. The immediate effect of EBP for SIH might cause acute elevation of intracranial pressure, sub­sequent urgent evacuation of CSDH should be prepared.

Blunt cerebrovascular injury (BCVI) is rare, accounting for 1–2% of all blunt injuries, but 10–20% may develop a stroke, resulting in morbidity or mortality. Although screening criteria for diagnosis are indicated, stroke due to BCVI may occur even in cases with minor injuries that meet no criteria, and early diagnosis before the onset of a stroke is difficult. Traffic accidents are the most common cause of trauma, and 60–80% of traumatic internal carotid artery occlusion cases occur within 24 hours after the injury. Still, in rare cases, it occurs later than seven days. We experienced a tandem occlusion of the extracranial carotid artery and middle cerebral artery due to the internal carotid artery dissection 23 days after a minor traffic accident without head or neck trauma. Mechanical thrombectomy combined with intravenous administration of recombinant tissue plasminogen activator was performed, and good recanalization was obtained. Carotid artery stenting was suc­cessfully added for the residual pseudoaneurysm of the internal carotid artery seven days after the initial treatment. The patient recovered well and was transferred to another hospital for rehabilitation.

BCVI sometimes occurs even if minor injuries do not meet the previously proposed screening criteria and rarely cause a cerebral infarction more than seven days after the initial injury. Some reports recommend more comprehensive cervical vessel screening in minor trauma patients. As a treatment, especially in patients with residual stenosis or pseudoaneurysm, endovascular stenting is effective in addition to medical therapy for stroke prevention.

A 51–year–old man with a head injury was taken to our hospital. The patient showed loss of consciousness and right–sided paralysis. Head computed tomo­graphy (CT) detected left fronto–parietal lobe hematoma and midline shift. At initial imaging, CT angiography (CTA) revealed no obvious vascular malformations or arteriovenous shunts. Although the cause of hemorrhage was unknown, a skull fracture with subcutaneous left parietal hematoma was observed. Therefore, the hemorrhage was determined as a traumatic intra­cerebral hematoma. Hematoma removal was performed to save the patient’s life. The fracture line extended to the superior sagittal sinus (SSS) and there were concerns about occurrence of sinus laceration due to craniotomy. Thus, digital subtraction angiography (DSA) was performed in a hybrid operating room to determine the cause of hemorrhage under general anesthesia. Furthermore, DSA revealed a shunt near the SSS, which was diagnosed as a dual arteriovenous fistula (dAVF). Since the shunt point was located just below the fracture site, the shunt appeared to be a traumatic dAVF. Prior to hematoma removal, we decided to perform trans–arterial emboliza­tion using Onyx^TM liquid embolic agent (Onyx). The shunt was resolved after injecting 0.59 cc of Onyx via the left middle meningeal artery. Moreover, craniotomy was continued for hematoma removal. After incising the dura, a contused brain filled with hematoma and subarachnoid hemorrhage was observed. The hematoma was removed as far as possible under the microscope. The bone fragments were returned and the wound was closed after confirming adequate de­compression. After intensive care, the patient was transferred to a rehabilitation hospital with a modified Rankin Scale of 4. Herein, we encountered a case of traumatic intracerebral hematoma with dAVF that was treated with hematoma removal after endovascular therapy. Even in cases of intracerebral hematoma caused by head trauma, it is important to inspect for any vascular abnormalities. Furthermore, the hybrid operating room might be an effective tool particularly for patients with traumas who require vascular evaluation, endovascular treatment, and craniotomy in a single procedure.

A penetrating head injury can result in bleeding from damaged blood vessels following removal of the foreign body; therefore, it is desirable to remove the foreign body once hemostasis can be achieved. We report a case of a transorbital penetrating injury with a deviated intracranial internal carotid artery (ICA) by a wooden stick–shaped foreign body, which was surgically removed in a hybrid operating room. A 60–year–old female accidentally fell and presented to the hospital the following day with left eyelid swelling. Her vital signs were stable, and there were no abnormal neurological findings. A head computed tomography (CT) scan showed a low–absorption foreign body penetrating the ethmoid sinus from the left medial orbit extending to the right side of the sella turcica. Cerebral angio­graphy revealed no apparent vascular injury of the right ICA. However, the cavernous and paraclinoid segments of the ICA were compressed and shifted by the foreign body. Considering the risk of vascular injury during removal of the foreign body, a balloon occlusion test was per­formed, which confirmed ischemic tolerance of parent vessel occlusion in case of massive arterial bleeding. Surgery was performed in a hybrid operating room. An otorhinolaryngologist endoscopically ob­served the nasal cavity, and a plastic surgeon removed the foreign body. We successfully confirmed corrected deviation of the ICA and total removal of the foreign body using a hybrid angio–CT system. Head magnetic resonance imaging (MRI) on day 6 showed no traumatic changes in the brain parenchyma. Cerebral angiography on day 8 showed no signs of damage to the ICA, and the patient was discharged home on day 9. Although perforating trauma to the head is relatively rare, it can be fatal. Using a hybrid operating room for foreign body extirpation in the case of perforating head trauma with possible intracranial vascular injury would enhance surgical safety by allowing rapid evaluation and the selection of appropriate treatment for vascular injury.

A 63–year–old man developed a delayed intraorbital sub­periosteal hematoma after a head trauma. Hemostasis was difficult despite using fresh frozen plasma, surgery, and transarterial embolization. Therefore, he was diag­nosed with acquired hemophilia A (AHA) based on prolonged activated partial thromboplastin time (APTT), factor VIII activity (<1%), and the factor VIII inhibitor (6 BU/ml). Hemostasis was achieved through bypass therapy, involving recombinant activated factor VII, after which the resolution of autoantibodies was achieved through immunosuppressive therapy using cortico­steroids. Although AHA is a rare, it is a potentially fatal bleeding disorder; hence early diagnosis and treatment are crucial. Therefore, it is important to suspect the syndrome when patients present with clinical findings suggestive of coagulation abnormalities, such as per­sist­ent bleeding despite appropriate treatment, average platelet count, normal prothrombin time, and prolonged APTT.

Background: Transorbital penetrating injuries from foreign bodies are relatively uncommon, and their management is often complex. They are often associated with injuries of blood vessels such as cavernous sinus and internal carotid artery (ICA). We report a case of transorbital penetrating injury with traumatic carotid cavernous fistula (CCF) treated by interventional radiology.

Case Description: A 49–year–old woman attempted suicide by sticking a chopstick through her right orbit. Computed tomography showed the chopstick penetrating the cavernous sinus, pons, and fourth ventricle. Digital subtraction angiography demonstrated a right CCF with an oc­clusion of the ipsilateral ICA. Parent artery occlusion (PAO) of the injured ICA was performed by proximal and distal approach to the lesion, and the foreign body was removed percutaneously after endovascular treatment. At the 4 months follow–up, she remained stable with no findings of the recurrent CCF and infection.

Conclusion: Endovascular PAO proximally and distally for the CCF with an occlusion of ipsilateral ICA might be an effective treatment option avoiding a fatal intracranial hemorrhage. Because of the variety of injuries to the ICA due to the transorbital penetrating trauma, treatment should be selected on the basis of the angiographic examination prior to removal of the foreign body.

Disseminated intravascular coagulation (DIC) is characterized by bleed­ing tendency resulting from consumptive coagulopathy and secondary fibrinolysis. Abdominal aortic aneurysm (AAA) is a representative disease presenting with chronic DIC, and severe bleeding symptoms due to increased fibrinolysis may be problematic. We report a case of chronic subdural hematoma (CSDH) that was difficult to treat due to DIC associated with AAA and endovascular aneurysm repair (EVAR). An 83–year–old female underwent EVAR for AAA 7 years ago, and developed DIC 2 years ago. She was admitted to our hospital because of right hemiparesis and consciousness disturbance. Computed tomography showed bilateral subdural hematoma, and laboratory examination revealed DIC. We performed burr–hole surgery and placed a left subdural drainage tube. The drainage tube was removed on postoperative day 1. On day 3, her level of consciousness deterio­rated and computed tomography revealed rebleeding. We performed hematoma removal and irrigation, and replaced the drainage tube. Since the CSDH recurred three times, we performed continuous CSDH drainage, and provided a daily fresh–frozen plasma infusion. Nine days later, the drainage tube was removed without rebleeding. We believe that AAA and/or EVAR might cause DIC and should be noted as medical history. In the treatment of CSDH with DIC, it is important to perform long–term drainage of the CSDH and to fully stabilize the coagulation and fibrinolytic system through daily transfusion therapy.