Intracranial-intracranial bypass strategies for the treatment of complex intracranial aneurysms: anatomical characteristics and surgical intervention.

OBJECTIVE: The effectiveness of revascularization for complex aneurysms is well-established. This study aimed to describe the technical characteristics and clinical efficacy of intracranial-to-intracranial (IC-IC) bypass for the treatment of complex intracranial aneurysms. METHODS: We retrospectively reviewed all patients with aneurysms who underwent a preplanned combination of surgical or endovascular treatment and IC-IC bypass at our institution between January 2006 and September 2023. IC-IC bypass techniques included four strategies: type A (end-to-end reanastomosis), type B (end-to-side reimplantation), type C (in situ side-to-side anastomosis), and type D (IC-IC bypass with a graft vessel). RESULTS: During the study period, ten patients with aneurysms each underwent IC-IC bypass surgery. Aneurysms were located in the middle cerebral artery (60.0%), anterior temporal artery (10.0%), anterior cerebral artery (20.0%), and vertebral artery (10.0%). There were three saccular aneurysms (30.0%), two fusiform aneurysms (20.0%), one dissecting aneurysm (10.0%), and four pseudoaneurysms (40.0%). We performed the type A strategy on five patients (50.0%), type B on one (10.0%), type C on one (10.0%), and type D on three (30.0%). During a mean period of 68.3 months, good clinical outcomes (modified Rankin Scale score, 0-2) were observed in all patients. Follow-up angiography demonstrated complete aneurysmal obliteration in all patients and good bypass patency in nine of ten patients (90.0%). CONCLUSION: The treatment of complex aneurysms remains a challenge with conventional surgical or endovascular treatments. IC-IC bypass surgery is a useful technique, associated with favorable clinical outcomes, for treating complex aneurysms.

Spontaneous Acute Epidural Hematoma Associated With Metastatic Hepatocellular Carcinoma: A Case Report.

Spontaneous acute epidural hematoma (AEDH) co-occurring with metastatic hepatocellular carcinoma (HCC) of the skull is rare, with only 7 documented cases in existing literature. This report describes the case of a 42-year-old man who presented with decreased consciousness following intermittent headaches following minor head trauma. Computed tomography imaging revealed an AEDH, prompting surgical intervention. Despite preliminary assumptions linking the causes of the trauma, surgical exploration revealed no evidence of traumatic injury. Instead, an infiltrative soft-tissue mass within the skull was identified. Histopathological examination confirmed that the mass was a metastatic HCC. Despite the successful hematoma evacuation, the patient's neurological status did not improve. This case underscores the importance of considering metastatic disease in the differential diagnosis of AEDH, particularly in patients with a history of malignant tumors, irrespective of prior indications of bone metastasis. Furthermore, it emphasizes the need to enhance diagnostic and therapeutic strategies for such complex cases.

Differences in gross appearance and histopathology of the outer membrane of the subdural hematoma envelope over time: A respective case series and literature review.

RATIONALE: Chronic subdural hematoma (CSDH) is a common disorder among elderly males. The most common theory of its cause is a minor brain injury resulting in the rupture of a bridging vein. The outer membrane of subdural hematoma (SDH) evolves like cutaneous wound healing with different phases. This report aims to use a surgical microscope and an electron microscope to show the pathophysiological differences in the temporal flow of the outer membrane of SDH. PATIENT CONCERNS: This study retrospectively reviewed the cases of 6 patients who underwent craniotomy from 2016 to 2021 at the single center of Chonnam National University Hospital. DIAGNOSES: These patients had a history of intracranial hematoma (ICH) at the surgical site on brain computed tomography (CT) before craniotomy. This study aimed to observe the morphological changes over time in the outer membrane of SDH and analyzed them through macroscopic and pathological findings. INTERVENTIONS AND OUTCOMES: The outer membrane of SDH was confirmed in all six patients who underwent surgery, and macroscopic analysis was performed using an operating microscope. Three patients underwent pathological analysis through histological examination, and through this, the difference according to ICH occurrence and detection time was analyzed. LESSONS: This study suggests that the outer membrane of SDH contains inflammatory and collagen cells in the early stages and thickens over time. This healing response is similar to cutaneous wound healing.

Occipital artery bypass importance in unsuitable superficial temporal artery: Two case reports.

BACKGROUND: Superficial temporal artery-middle cerebral artery (STA-MCA) bypass helps treat cerebral ischemia. However, the STA is not available for bypass in some conditions. Therefore, with some technical tips, the authors introduced a bypass technique using the occipital artery (OA). CASE SUMMARY: Two female patients complained of hemiparesis. Brain magnetic resonance imaging (MRI) indicated contralateral infarction from the MCA steno-occlusion. On Diamox single photon emission computed tomography or perfusion MRI, the contralateral front parietotemporal reserve was diminished. On transfemoral cerebral angiography, the STA was thin with a weak flow; however, the OA was prominent. Direct OA-MCA end-to-side extracranial-intracranial bypass surgery was implemented instead of STA because the caliber was too narrow. The postoperative course was uneventful in both cases, with well-maintained bypass patency and neurological stability during follow-up. CONCLUSION: OA might be an acceptable alternative for MCA cerebral ischemic cases with an unsuitable STA.

Primary cutaneous apocrine carcinoma of the scalp: Two case reports and literature review.

RATIONALE: Apocrine carcinoma is a rare malignant sweat gland tumor that has been reported in approximately 200 cases. This tumor usually occurs in the axilla, but in rare cases, it can also develop in the scalp. In the present work, we report 2 cases of cutaneous apocrine carcinoma of the scalp. PATIENT CONCERNS: Two men visited our outpatient clinic with recurrence of tumor after undergoing surgery for scalp tumor at another hospital. DIAGNOSES: Brain magnetic resonance imaging of a 56-year old man showed the presence of a 5.0 × 4.5 × 4.4 cm scalp mass in the right parietal region, invading the skull and dura mater and a 2.2 × 2.0 × 0.7 cm bony mass without any skin lesions right next to the scalp mass. Neck magnetic resonance imaging of a 76-year-old man revealed the presence of a well-defined oval mass in the subcutaneous layer of the left occipital scalp and 2 enlarged lymph nodes in the left neck. Definite diagnoses were made postoperatively. The patients were diagnosed with cutaneous apocrine carcinoma. The diagnosis was confirmed through histopathological and immunohistochemical staining tests. INTERVENTIONS: The tumors were removed with a wide safety margin and reconstructive surgery was performed. OUTCOMES: Additional radiotherapy or chemotherapy was performed. Follow-up more than 6 months revealed no recurrence or metastasis. LESSONS: If accurate diagnosis and treatment had taken place at the initial stages of the primary cutaneous apocrine carcinoma, it would have been possible to prevent recurrence and intracranial invasion. As recurrent primary cutaneous apocrine carcinoma can become aggressive and difficult to treat, even a small mass on the scalp must be evaluated carefully and treated properly.

A study on the proper catheter position in minimally invasive surgery using stereotactic aspiration plus urokinase for intracerebral hemorrhage.

OBJECTIVE: The surgical method for treating spontaneous intracranial hemorrhage (ICH) is not well established despite ICH's high prevalence and poor prognosis. Minimally invasive surgery has recently received attention; however, literature on this method is scarce. In particular, the appropriate location of the catheter in the hematoma has not been described. We examined whether the catheter position affects the hematoma reduction in a hematoma ＞50 cc. METHODS: We investigated the prognoses of 36 patients with ICH who underwent stereotactic aspiration and hematoma drainage using urokinase from January 2010 to December 2018 and the hematoma reduction rates according to the tube position. Two methods evaluated the position of the catheter. In the first method, the hematoma was an imaginary sphere. The center point was set as the operation target. We evaluated the catheter position by determining whether it was in the deep part or the outer part of the half point from that location to the hematoma margin. In the second method, we evaluated whether the catheter was located 1 cm inside the hematoma margin. RESULTS: In both the first and second evaluations, there were no differences in age, midline shift, intraventricular hemorrhage status, hematoma volume on admission, Glasgow Coma Scale score on admission, time to operation after symptom onset, and systolic blood pressure. The rates of decrease in bleeding and the prognoses were also not significantly different. CONCLUSIONS: If the catheter is in the hematoma, the rate of hematoma reduction at any position is similar.

Real-world evidence on the strategy of olmesartan-based triple single-pill combination in Korean hypertensive patients: a prospective, multicenter, observational study (RESOLVE-PRO).

BACKGROUND: In this prospective, multicenter, non-comparative observational study, the effectiveness and safety of the triple single-pill combination (SPC) of olmesartan/amlodipine/hydrochlorothiazide (OM/AML/HCTZ) were evaluated in a real clinical practice setting in Korean patients with essential hypertension. METHODS: A total of 3752 patients were enrolled and followed for 12 months after administration of OM/AML/HCTZ. Primary endpoint was change from baseline to month 6 in the mean systolic blood pressure (SBP). Secondary endpoints included changes from baseline in the mean SBP at month 3, 9, 12 and the mean diastolic blood pressure (DBP) at month 3, 6, 9, 12; changes in the mean SBP/DBP according to age and underlying risk factors; and blood pressure control rate (%) at different time points. Adherence to and satisfaction with OM/AML/HCTZ treatment among patients and physicians were assessed by medication possession ratio (MPR) and numeric rating scale, respectively, as exploratory endpoints. Safety was evaluated by the incidence and severity of adverse events (AEs) as well as the discontinuation rate due to AEs. RESULTS: OM/AML/HCTZ administration led to significant reductions in the mean SBP/DBP by 11.5/6.6, 12.3/7.0, 12.3/7.2, and 12.8/7.4 mmHg from baseline to month 3, 6, 9 and 12, respectively (P < 0.0001). The BP reductions were maintained throughout the 1-year observation period in all patients with different age groups and risk factors (diabetes mellitus, cardiovascular disease, and renal disease). The BP control rate (%) of < 140/90 mmHg was 65.9, 67.9, 68.9, and 70.6% at month 3, 6, 9, and 12, respectively. The mean MPR during the observation period was 0.96. The safety results were consistent with the previously reported safety profile of OM/AML/HCTZ. CONCLUSIONS: Treatment with the triple SPC of OM/AML/HCTZ demonstrated significant effectiveness in reducing SBP/DBP and achieving target BP control with high adherence over the 1-year observation period in Korean hypertensive patients and was well-tolerated. TRIAL REGISTRATION: CRIS, KCT0002196 , Registered 3 May 2016.

Systemic macrophage depletion attenuates infarct size in an experimental mouse model of stroke.

OBJECTIVE: Macrophages have been shown to play important roles in various pathophysiological processes of the central nervous system via neuroinflammation, leading to an increased interest in macrophage biology. Circulating blood monocytes are among the first cells to infiltrate the brain after ischemic stroke; however, the role of innate immune cells such as monocytes and macrophages remains to be elucidated. Here, we investigated the association between blood monocytes and infarct size following ischemic stroke. METHODS: We induced stroke using a focal ischemia mouse model through middle cerebral artery suture occlusion. To deplete circulating blood monocytes, clodronate was injected intraperitoneally 24 h before the surgery. Animals were sacrificed at specified time points, and the infarct size and mRNA expression were then measured. RESULTS: The clodronate-injected mice showed significantly smaller infarct size than the control mice. Immunohistochemical staining revealed that monocyte depletion significantly blocked the infiltration of macrophages and microglia. The mRNA expression levels of macrophage and microglia markers were higher in the left infarcted brain than in the right non-infarcted brain. CONCLUSIONS: In summary, monocyte depletion reduced the infarct size and mitigated neurological deficits in mice following ischemic stroke, likely by blocking the infiltration of inflammatory cells such as macrophages and microglia.

Clinical warning signs of life-threatening hematochezia in neurosurgical patients with long-term bed rest: Three cases report.

RATIONALE: Patients with long term bed rest in intensive care unit after neurosurgery could experience splanchnic hypoperfusion. These patients have several other medical conditions that exacerbate splanchnic hypoperfusion during treatment and the splanchnic hypoperfusion could result in "stress-induced intestinal necrosis", which could cause massive hematochezia. We report here the experience of life-threatening hematochezia in 3 patients who underwent brain surgery in our institution. PATIENTS CONCERNS: One female patient (72-year-old) and 2 male patients (58- and 35-year-old) were admitted to our institution because of traumatic intracerebral hemorrhage, subarachnoid hemorrhage due to a ruptured anterior communicating artery, and subarachnoid hemorrhage with unknown cause respectively. All patients underwent emergency brain surgery for diagnosis and treatment. After surgery, they all experienced long-term bed rest in intensive care unit. Hematochezia occurred on postoperative day 15, 17, and 49, respectively. DIAGNOSES: All of the patients were assessed by abdomen/pelvis computed tomography and underwent a colonoscopy. INTERVENTIONS: The female patient underwent embolization through pelvic arteriography and epinephrine injection through colonoscopy, but a total colectomy and ileostomy was performed due to refractory hematochezia. 58-year-old male patient had a laparoscopic ileostomy for the bowel rest. The other patient underwent nil per os and conservative treatment for 2 weeks. OUTCOMES: The female patient was discharged without further treatment plan, 58-year-old male patient survived after laparoscopic ileostomy, while the other patient survived after 2 weeks of nil per os. LESSON: Abdominal symptoms, such as hematochezia, should be actively managed in neurosurgical patients who are undergoing long-term bed rest in an intensive care unit under physiologically stressful medical conditions.

Contralateral Brain Atrophy in Conservatively Treated Primary Intracerebral Hemorrhage.

BACKGROUND: In patients with intracerebral hemorrhage (ICH), brain volume loss can occur in the hemisphere ipsilateral to the hematoma. However, contralateral hemispheric volume change after ICH is not well known. The present study aimed to investigate contralateral brain volume changes in patients with ICH who had not undergone surgery. METHODS: Of the 2213 patients with ICH admitted to our hospital between January 2010 and December 2017, 46 patients without surgical intervention were included in the present study. We measured contralateral hemispheric brain volume in the axial images of brain computed tomography at the time of ICH onset and after 12 months. We analyzed the relationship between various factors and volume changes in the contralateral hemisphere. RESULTS: The mean change percentage between the initial and follow-up contralateral parenchyma volume was 96.84%. The average volume decreased by 3.16% (P = 0.001). Univariate and multivariate logistic regression models revealed no significant factors associated with contralateral brain volume loss. Kruskal-Wallis test and Mann-Whitney U test showed no statistical significance (P = 0.824, P = 0.122) between ICH volume groups. CONCLUSIONS: Contralateral parenchymal volumes were significantly decreased at follow-up brain computed tomography scanning; these changes may provide important clinical information on the remote effect of focal lesion and symptoms in the course of ICH treatment. However, further investigation is required to determine the mechanisms underlying these volume changes.

Preoperative Considerations in Occipital Artery-high-riding Posterior Inferior Cerebellar Artery Bypass: A Report of Two Cases and a Literature Review.

Nonsaccular vertebral artery aneurysms involving the posterior inferior cerebellar artery (PICA) are rare. Treatment is considered a significant challenge because of their angiographic and anatomical features, especially in high-riding PICA. Therefore, meticulous preoperative angiographic and anatomical evaluation is necessary. Moreover, consideration of the distance between the cerebellar skull base and caudal loop of the PICA is important. We present two cases of occipital artery-high-riding PICA bypass and discuss important preoperative technical considerations.

Bifrontal Interhemispheric Approach Involving Cutting the Superior Sagittal Sinus for Distal Anterior Cerebral Artery Aneurysms.

BACKGROUND: The unilateral interhemispheric approach for distal anterior cerebral artery aneurysms presents several risks, such as postoperative venous infarction due to occasional sacrifice of parasagittal bridging vein and postoperative frontal lobe damage due to retraction force. To overcome these risks, we used a bifrontal craniotomy with straight dural incision and cutting of the superior sagittal sinus. METHODS: We retrospectively reviewed 61 patients (42 unruptured and 19 ruptured A2 and A3 aneurysms) who under aneurysm clipping through bifrontal interhemispheric approach between March 2007 and December 2017. There were 35 A2 aneurysms and 27 A3 aneurysms, and mean size of aneurysms was 5.45 mm. The modified bifrontal interhemispheric approach involved 3 steps: bifrontal craniotomy of centrobasal portion of the frontal bone, ligation and division of anterior one third of the superior sagittal sinus, and approaching the aneurysm via the interhemispheric space. All patients underwent computed tomography on postoperative days 3 and 7 for evaluation of brain retraction damage or venous infarction. RESULTS: Among patients with ruptured aneurysms, 79% had a favorable outcome (Glasgow Outcome Scale score 4 or 5) 6 months after primary subarachnoid hemorrhage; all patients with unruptured aneurysms had favorable outcomes. Surgical outcome was strongly related to preoperative neurologic Hunt and Hess grade. Three patients had poor outcomes due to poor Hunt and Hess grade on admission (grade 3 in 2 patients, grade 4 in 1 patient). Follow-up CT showed that venous infarction did not occur in any of the patients. CONCLUSIONS: Modified bifrontal interhemispheric approach may be a safe and effective method for treating A2 and A3 aneurysms with relatively good clinical outcome and no surgery-related complications.

Pericranial Flap Anterior Skull Base Reconstruction With Gelfoam Intradural Compression.

Anterior cranial base reconstruction is occasionally necessary following severe trauma. Several methods for reconstruction have been described and some authors have described their experiences regarding the use of a pericranial flap for anterior skull base reconstruction after trauma. A 26-year-old woman was admitted to our department with multiple facial bone fractures identified using facial bone computed tomography. Plastic surgeons performed surgery under general anesthesia for the patient's nasal bone fractures. On the seventh day after admission, the patient's brain computed tomography showed an abscess in the frontal lobe. Antibiotic treatment was started, but the lesion deteriorated. Anterior skull base reconstruction was then performed using a pericranial flap with gelfoam compression. No complications, including leakage of cerebrospinal fluid, cerebral hemorrhage, necrosis of the pericranial flap, or frontal lobe herniation, were observed 1 year following surgery. In our case, the authors performed a simple and effective treatment with reconstruction using pericranial flap and gelfoam compression without complications. This technique is useful for reconstructing defects in the base of the frontal bone resulting from various causes, as well as for fracture of the anterior skull base following trauma.

Contralateral Hemispheric Brain Atrophy After Primary Intracerebral Hemorrhage.

OBJECTIVE: In patients with intracerebral hematoma (ICH), it is well known that brain atrophy occurs in the hemisphere ipsilateral to the hematoma. The present study aimed to investigate contralateral hemispheric volume changes in patients with ICH as well as related factors. METHODS: Of 112 patients with ICH who were surgically treated at our hospital between January 2011 and December 2015, 44 were included in the present study. We measured contralateral hemispheric brain areas in 3 planes of axial brain computed tomography images. We obtained the proportion of contralateral hemispheric parenchyma to the hemispheric intracranial area to adjust for individual differences in head size. We analyzed the relationship between various factors and volume changes in the contralateral hemisphere. RESULTS: The average volume percentages of preoperative and follow-up contralateral hemispheric parenchyma were 92.3% versus 88.8%, 90.3% versus 85.3%, and 86.9% versus 82.5% in the level of foramen of Monro, septum pellucidum, and lateral ventricle, respectively. These decreases were all statistically significant (paired t-test; P < 0.001). As far as the causes of these decreases, the presence of intraventricular hematoma was the most significant factor for a decrease (P = 0.006). Glasgow coma scale score on arrival, as well as, smoking were independent factors in a multivariate analysis (P = 0.016, 0.039). CONCLUSIONS: Contralateral parenchymal volumes were significantly decreased at the 3-month follow-up brain computed tomography scan. These findings may offer important clinical information on the remote brain injury of ICH.

The Clinical Importance of Perforator Preservation in Intracranial Aneurysm Surgery: An Overview with a Review of the Literature.

Clipping for intracranial aneurysms is done to achieve complete occlusion of the aneurysm without a remnant sac. Despite modern advancements of neurosurgical techniques, morbidity related to the clipping of intracranial aneurysms still exists. Clip occlusion of a parent artery or small hidden perforators commonly leads to permanent neurological deficits, and is a serious and unwanted complication. Thus, preserving blood flow in the branches and perforators of a parent artery is very important for successful surgery without postoperative morbidity and mortality. The aim of this review article is to discuss the consequences of perforator injury and how to avoid this phenomenon in aneurysm surgeries using intraoperative monitoring devices.

Correct Plane of the Sylvian Vein Dissection for Middle Cerebral Artery Aneurysm Using Indocyanine Green Videoangiography.

BACKGROUND: Preservation of the superficial Sylvian veins (SSVs) is essential to prevent neurologic deficits during Sylvian dissection. We describe an appropriate surgical approach for unruptured middle cerebral artery (MCA) aneurysms to preserve these veins by using indocyanine green videoangiography (ICG-VA). METHODS: Between August 2014 and August 2015, we performed microsurgical clipping for 37 unruptured MCA aneurysms in 36 patients. We classified all of the cases into 3 types according to the location between the Sylvian fissure and the SSV. We defined 3 surgical approaches (frontosylvian, intersylvian, and temporo-sylvian) based on the SSV and investigated the proper surgical approach according to the type of case. RESULTS: In our study, most SSVs were located above the Sylvian fissure (fissure type, 64.9%). The SSV was located on the temporal lobe in 10 cases (temporal type) and on the frontal lobe in 3 cases (frontal type). The frontosylvian approach (splitting between the SSV and frontal lobe) was performed in all of the patients with temporal type; the temporo-sylvian approach (splitting between the SSV and temporal lobe) was performed in all of the patients with frontal type and single SSV of fissure type. The intersylvian approach (splitting between the frontal and temporal SSV, or among multiple SSVs) was successfully performed in the patients with double or multiple SSVs of fissure type. No venous complications occurred that were related to the surgical approach. CONCLUSIONS: Correct dissection strategy using intraoperative ICG-VA is greatly useful to define the optimal surgical approach without vein injury.

Sunken Eye Induced by Superior Orbital Wall Defect After Craniofacial Surgery.

Enophthalmos after a ventriculo-peritoneal (V-P) shunt placement is very rare. Previous defects of the orbital wall with intracranial hypotension can cause enophthalmos after V-P shunting. The authors present 2 patients of enophthalmos with orbital wall defects resulting from anterior clinoidectomy that was performed during previous aneurysmal surgery. Both patients received a V-P shunt for hydrocephalus after subarachnoid hemorrhage. Although the hydrocephalus was improved by V-P shunts in both patients, sunken eyes were observed. The patients received reconstructive surgery of the superior orbital wall using titanium mesh and recovered after surgery without any neurological deficits. Here, the authors present 2 patients of enophthalmos with orbital wall defects treated by orbital wall reconstruction.

Brain stem herniation secondary to cerebrospinal fluid drainage in ruptured aneurysm surgery: a case report.

BACKGROUND: A lumbar drainage catheter is frequently placed intra-operatively to decrease fluid pressure on the brain in aneurysmal subarachnoid cases. In rare cases, this catheter placement can lead to intracranial hypotension, resulting in brain stem herniation termed "brain sag" and it can lead to neurological injury and may prove to be fatal. We present our patient with brain sag secondary to intraoperative lumbar drainage. CASE DESCRIPTION: A 56-year-old woman was admitted with a sudden onset of severe headache. A computed tomography (CT) scan revealed diffuse subarachnoid hemorrhage with ruptured anterior communicating artery aneurysm. After general anesthesia, a lumbar drainage catheter was placed intra-operatively to reduce pressure on the brain and 50 cc of CSF was removed during a 5-h period. Three to five days after operation, her neurologic symptoms became worse with an altered mental state and pupillary asymmetry. CT and magnetic resonance imaging (MRI) showed slit lateral ventricles, effacement of the cisterns and an elongated brain stem. After placing the patient in the Trendelenburg position, the patient rapidly recovered to her baseline neurologic state. DISCUSSION: Typical complications of subarachnoid hemorrhage such as vasospasm or hydrocephalus also manifest as neurological deterioration, but their treatments differ greatly from those for brain sag. Thusly, it is important to distinguish between causes. Treatments such as lumbar or extra-ventricular drainage, induced hypertension or administration of mannitol must be stopped once brain sag is suspected. Also, care should be taken for typical imaging features of brain sag on CT or MRI scan. For brain sag, placing the patient in the Trendelenburg position can improve neurological status in a rapid fashion. CONCLUSIONS: Brain sag is a rare but serious condition and can be fatal if not rapidly diagnosed and treated. We therefore recommend including brain sag in the differential diagnosis, along with vasospasm, hydrocephalus or cerebral edema as part of possible complications following subarachnoid hemorrhage treatment. We hope our clinical and imaging data from this case study contribute to the correct diagnosis of brain sag, as its early detection is important.

Reconstructive Endovascular Treatment of an Intracranial Infectious Aneurysm in Bacterial Meningitis: A Case Report and Review of Literature.

BACKGROUND: Intracranial infectious aneurysms (IAs) are rare cerebrovascular lesions that represent only 1%-6% of all intracranial aneurysms. IAs are rare cerebrovascular lesions and pose a significant therapeutic challenge because of their angiographic and pathophysiologic features. We describe a patient with an intracranial IA treated by the use of reconstructive endovascular methods using a balloon-expandable covered stent and discuss the pathophysiologic characteristics of IA based on serial brain imaging findings. CASE DESCRIPTION: A 21-year-old man was admitted to our emergency department with headache and vomiting. Neurologic examination, hematologic workup, and cerebrospinal fluid examination confirmed a diagnosis of bacterial meningitis. Initial brain magnetic resonance angiography revealed no significant stenosis lesions or aneurysm. After 4 weeks of antibiotic treatment, follow-up brain magnetic resonance imaging revealed an 8-mm sized aneurysm on the petrous portion of the right internal carotid artery, and 3 months later, follow-up brain magnetic resonance angiography revealed that the aneurysm had increased in size from 8 to 15 mm. Conventional 4-vessel angiography confirmed the presence of a pseudoaneurysm. Endovascular treatment was then planned via the use of a balloon-expandable covered stent. Postoperatively, the patient was discharged without specific neurologic deficit. CONCLUSIONS: IAs are rare cerebrovascular lesions and pose a significant therapeutic challenge because of their angiographic and pathophysiologic features. Although endovascular treatment is not performed routinely for infectious aneurysms, the covered stent may represent a safe and effective treatment that achieves complete endoluminal reconstruction of the damaged vessel wall.

Specific and helpful intraoperative indocyanine green videoangiography finding of blood blister-like aneurysm of internal carotid artery.

BACKGROUND: Blood blister-like aneurysms (BBAs) account for 0.5-2.0 % of ruptured intracranial aneurysms. Because of their rarity, the natural history and pathophysiology of such aneurysms are not fully understood. We present two patients with BBAs treated with Bemsheets-covered clipping and discuss their pathophysiological characteristics, through the intraoperative and specific indocyanine green (ICG) video angiography (VA) findings. CASE REPORT: A 34-year-old male and a 53-year-old female were admitted to our emergency room with suddenly reduced levels of consciousness. Brain imaging studies demonstrated a blood blister-like aneurysm of the supraclinoid segment of the right ICA. Craniotomy and an attempt of surgical clipping were performed. ICG-VA showed the filling defect of dye in aneurysm in the operative field. The BBAs were clipped after being covered by Bemsheets (Kawamoto Corporation, Osaka, Japan) and then confirmed by the ICG-VA. Postoperatively, both patients showed transient neurological deficit due to vasospasms and recovered to their normal statuses within a few months after their respective operations. CONCLUSIONS: ICG-VA showed the filling defect of dye in BBAs, which supported that BBAs have been a pseudoaneurysm. In addition, although not routinely recommended in the treatment of BBAs, we believe that Bemsheet-covered clipping is a safe and effective treatment option for BBAs.