Spinal magnetic resonance imaging artifacts in lumboperitoneal shunt surgery using adjustable valve implantation on the paravertebral spinal muscles.

BACKGROUND: Adjustable shunt valves that have been developed for managing hydrocephalus rely on intrinsically magnetic components ; thus, artifacts with these valves on magnetic resonance imaging (MRI) are inevitable. No studies on valve-induced artifacts in lumboperitoneal shunt (LPS) surgery have been published. Therefore, this study aimed to evaluate valve-induced artifacts in LPS. METHODS: We retrospectively reviewed all MRIs obtained between January 2023 and June 2023 in patients with an implanted Codman CERTAS Plus adjustable shunt valve (Integra Life Sciences, Princeton, New Jersey, USA). The valve was placed <1 cm subcutaneously on the paravertebral spinal muscle of the back, with its long axis perpendicular to the body axis. The scans were performed using a Toshiba Medical Systems 1.5 Tesla scanner. The in-plane artifact sizes were assessed as the maximum distance of the artifact from the expected region of the back. RESULTS: All spinal structures or spinal cords can be recognized, even with valve-induced artifacts. The median maximum valve-induced artifact distance on T1-weighted axial imaging was 25.63 mm (mean, 25.98 mm ; range, 22.24-30.94 mm). The median maximum valve-induced artifact distance on T2-weighted axial imaging was 25.56 mm (mean, 26.27 mm ; range, 21.83-29.53 mm). CONCLUSION: LPS surgery with adjustable valve implantation on paravertebral muscles did not cause valve-induced artifacts in the spine and spinal cord. We considered that LPS could simplify the postoperative care of these patients. J. Med. Invest. 71 : 154-157, February, 2024.

Usefulness of non-slip element percutaneous transluminal angioplasty scoring balloons in treating severe calcified lesions of the carotid artery for carotid artery stenting: A case report.

Background: Treatment of calcified lesions with conventional angioplasty balloons can be difficult due to insufficient lumen expansion, high dissection rates, and repeated revascularization. We report a case in which a scoring balloon was used in lesions resistant to angioplasty with a semi-compliant balloon. Case Description: A 72-year-old man presented with severe stenosis and a highly calcified lesion in the right cervical internal carotid artery. Right carotid artery stenting (CAS) was planned to prevent future ischemic stroke events. Conventional semi-compliant balloon angioplasty was unsuccessful. Three inflations of a non-slip element (NSE) percutaneous transluminal angioplasty (PTA) scoring balloon (Nipro, Osaka, Japan) successfully achieved CAS without complications. Conclusion: This is the first report to describe the use of this scoring balloon in de novo carotid artery disease. NSE PTA scoring balloon catheters can be a useful option for refractory, highly calcified stenosis.

Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review.

Spinal dural arteriovenous fistula (SDAVF) is among the most common arterial shunt diseases typically found in middle aged or older men. Herein, we aimed to clarify the reasons for misdiagnoses and delayed diagnoses of SDAVF, determine how these affect prognoses, and establish how they can be prevented. We conducted a PubMed/MEDLINE literature search using "spinal dural arteriovenous fistula", "delayed diagnosis", "late diagnosis", and "misdiagnosis" terms. We identified 18 articles, including 965 SDAVF cases. Patients were predominantly males (71.8-100.0%) (mean age: 53.5-71.0 years). Misdiagnoses rates varied (17.5-100.0%) and encompassed many conditions. The mean time between early manifestations and confirmed diagnosis was approximately 10-15 months and from the first radiologic image revealing dural arteriovenous fistula (DAVF) features to diagnosis was 9.2-20.7 months. Posttreatment outcomes showed a significant improvement in motor functions, gait, and micturition, particularly in patients exhibiting preoperative symptoms over a short period. SDAVF is frequently misdiagnosed or subject to delayed diagnosis, causing poor clinical outcomes. SDAVF symptoms including progressive lower-limb weakness, paresthesia, and vesicorectal dysfunction are indications for spinal magnetic resonance imaging with subsequent spinal angiography, wherein DAVF is evidenced by extensive T2 hyperintensity and flow-void abnormalities. We reported a representative case with delayed diagnosis.

Rare complication of lumboperitoneal shunt with distal catheter migration into the inguinal hernia sac in two adults: A case report.

Background: Despite the proven benefits of lumboperitoneal shunt (LPS) for idiopathic normal-pressure hydrocephalus, complications such as catheter migration remain a problem. Inguinal complications of the distal catheter are rare in adults, and their management is uncertain. Herein, we present two cases of distal catheter migration into the inguinal hernia sac after LPS in adults and recommend their management. Case Description: An 86-year-old man presented with inguinal swelling. In another 82-year-old man who did not show any improvement after LPS, shunt angiography revealed LPS dysfunction due to lumbar catheter occlusion and distal LPS catheter in the right inguinal hernia sac, and lumbar catheter reconstruction was performed. Both patients did not have any symptoms, except inguinal swelling, and were followed up. After 2 weeks and 4 days, the distal catheter moved into the peritoneal cavity. Conclusion: Inguinal complications due to the migration of the distal catheter into the inguinal hernia sac are rare in LPS because frequent movements of the distal catheter due to trunk rotation dislodge it from the inguinal hernia sac for a short period. Urgent surgery was not recommended because the catheter was moved in a short period and the patients did not wish to undergo hernia repair.

Surgical Treatment of Vertebral Compression Fracture in a Patient with Idiopathic Normal Pressure Hydrocephalus.

Idiopathic normal pressure hydrocephalus (iNPH) with gait disturbance can be effectively treated with a cerebrospinal fluid shunt. Furthermore, balloon kyphoplasty (BKP) is a successful minimally invasive treatment for osteoporotic vertebral compression fractures (VCFs). This case report presents the surgical management of an elderly patient with iNPH who presented after a VCF due to a fall. A 77-year-old woman who had been experiencing progressive gait disturbance for five years reported experiencing back pain one month after a fall. Imaging revealed a recent L1 VCF that did not compromise the spinal canal. Furthermore, the Mini-Mental State Examination results and the timed up-and-go test were 20 points and 17.96 seconds, respectively. Magnetic resonance imaging revealed ventriculomegaly with an Evans' index of 0.35. Her symptoms improved temporarily after a tap test, and she was diagnosed with probable iNPH. BKP was performed for VCFs, followed by the lumboperitoneal (LP) shunt placement for iNPH one month later. Following the operation, her symptoms improved without complications. After one month of performing BKP, an LP shunt would be placed to prevent shunt complications, such as infection and catheter-related neurological symptoms. Screening for iNPH in the elderly who present after VCFs due to a fall may identify iNPH patients who may benefit more from surgical treatments.

Hands-on neuroendovascular practice for nonselective undergraduate medical students increases interest and aspirations in pursuing neurosurgery as a specialization.

Background: The number of medical students aspiring to become neurosurgeons has decreased worldwide, mainly due to poor work-life balance among neurosurgeons; therefore, recruiting students for neurosurgery is essential to ensure the availability and appropriate quality of neurosurgical treatment. This study aimed to evaluate the efficacy of hands-on neuroendovascular practice for nonselective undergraduate medical students to determine whether this increases their interest in neurosurgery and contributes to their aspirations of becoming neurosurgeons. Methods: Hands-on neuroendovascular practice for mechanical thrombectomy was performed by undergraduate 5th-year medical students during their 2-week clinical rotation in the Department of neurosurgery at our university hospital between April 2021 and March 2023. After the neurosurgery practice, a questionnaire about their understanding of neurosurgery and aspirations for this specialization before and after the practice was anonymously completed by all students. Results: Overall, 153 students completed the questionnaire. Of these, 140 (91.5 %) showed increased interest in neurosurgery after participating in the hands-on practice. Through this practice, the number of students who considered neurosurgery as their first choice or one of their specialty choices increased from 8 (5.2%) to 12 (7.8%) (P = 0.3534) and from 19 (12.4%) to 52 (34.0%) (P < 0.0001), respectively. Furthermore, the number of students with no aspiration to become neurosurgeons decreased from 95 (62.1%) to 43 (28.1%) (P < 0.0001). Conclusion: Hands-on neuroendovascular practice for nonselective undergraduate medical students effectively increased their interest in neurosurgery specialization and their desire to become neurosurgeons. Therefore, this practice can help recruit medical students for neurosurgery specialization.

A Case of Suspected Radiation-Induced Meningioma That Developed 36 Years after Radiotherapy for a Suprasellar Tumor.

Recently, the improvements in the prognosis of childhood brain tumors have made it necessary to consider the risk of radiation-induced brain tumor development in long-term survivors. In this report, we describe a case of radiation-induced meningioma (RIM) treated surgically 36 years after radiotherapy. A 46-year-old woman, who underwent craniotomy for suprasellar germ cell tumor at 10 years of age with additional postoperative radiotherapy, was admitted to the emergency room with consciousness disturbance and right hemiplegia. One year earlier, magnetic resonance imaging (MRI) revealed a 1-cm diameter tumor in the left middle cranial fossa. This MRI showed an enlarged brain tumor in same lesion with clearly enhanced by gadolinium. A RIM located on a left sphenoid ridge with a fast growth rate was diagnosed, and the gross total removal was achieved by a left frontotemporal craniotomy. Histological diagnosis of atypical meningioma (World Health Organization grade II) was made. RIMs are frequently atypical, anaplastic meningiomas that have already been treated with radiotherapy, making additional postoperative radiotherapy difficult; the removal rate must be increased to achieve a good prognosis. In the case of long-term survivors after childhood radiotherapy, a strict follow-up with the occurrence of RIM in mind is necessary.

The development of a new, ultra-fine, and flexible neuroendoscope for intracranial observation.

Background: A neuroendoscope is a technical advance that allows surgeons to visualize certain regions of the brain that was previously inaccessible through the use of a surgical microscope. Several neuroendoscope designs have been implemented by other neurosurgeons over the past 5 years. The advantage of a neuroendoscope is the addition of a flexible and narrow tip that allows for safe entry into intracranial structures for clinical observation. However, there are some limitations to this approach. Here, we report the use of a modified angioscope as a newly developed neuroendoscope to be employed in observing intracranial structures. Methods: We report the use of an angioscope that is 1.8 mm in diameter and has both a thin and flexible tip. In this study, the angioscope was inserted into the lumen of an aspirator tube, and the tip of the device was placed at the intracranial area of intended observation area. Image findings were evaluated using an established in vivo goat brain model. Results: The angioscope was light in weight and maneuverable and could be reached and observed in the blind spot using a surgical microscope. From the cerebellopontine angle, the lower cranial nerves and trigeminal nerve could be observed, and from the cisterna magna, the floor of the fourth ventricle and the aqueduct could be seen. Conclusion: The angioscope is a useful instrument to observe intracranial locations safely and effectively even within a limited surgical field. Further modifications will be required to use the angioscope in various craniotomy procedures.

Stent retriever angioplasty for acute atherosclerotic occlusion of internal carotid artery: A case report.

Background: Despite the proven benefit of stent retriever thrombectomy for acute ischemic stroke caused by large-vessel embolic occlusion, acute revascularization in the setting of underlying intracranial, atherosclerosis-related, and emergent large-vessel occlusion remains to be a challenge. In this case report, we present a novel revascularization technique that can be used to treat acute ischemic stroke caused by suspected intracranial, atherosclerosis-related, and emergent large-vessel occlusion of the internal carotid artery (ICA). Case Description: This case report presents two patients with intracranial, atherosclerosis-related, and emergent large-vessel occlusion of the ICA: a 73-year-old man with a right-sided hemiparesis and aphasia and a 60-year-old man with altered level of consciousness. These patients were treated using the prolonged deployment and partial resheath method with a stent retriever, using the following devices: Solitaire Platinum, Trevo Trak 21, and AXS catalyst 6 for suction. On prolonged deployment of the Solitaire Platinum device, underlying focal atherosclerotic disease was noted. The device remained in place for more than 10 min, until the blood vessel was occluded. Next, the device was partially resheathed into the Trevo Trak 21 to reduce the radial force and minimize vessel injury during the pull. The partially constrained device was then retrieved under continuous aspiration at the lesion site and blood flow was successfully restored. Both patients recovered without any new deficits. Conclusion: The prolonged deployment and partial resheath method using a stent retriever may be safe and effective in the treatment of intracranial, atherosclerosis-related, and emergent large-vessel occlusion of the ICA.

Trigeminal neuropathy after tozinameran vaccination against COVID-19 in postmicrovascular decompression for trigeminal neuralgia: illustrative case.

BACKGROUND: Vaccines against coronavirus disease 2019 have a high level of efficacy and safety across all populations. However, numerous case series have been published on neurological disorders, including Bell's palsy, Guillain-Barre syndrome, transverse myelitis, and multiple sclerosis. The authors presented a case of trigeminal neuropathy after coronavirus vaccination in a patient who had undergone microvascular decompression (MVD) for trigeminal neuralgia (TN). OBSERVATIONS: A 77-year-old woman presented with acute trigeminal neuropathy after receiving a Pfizer-BioNtech vaccination (tozinameran) against severe acute respiratory syndrome coronavirus 2. The patient had undergone MVD for TN and the facial pain completely disappeared. One month later, she received the first injection of the tozinameran vaccine. Twelve hours after vaccination, she presented with numbness and pain induced by touching any place on the entire right face. No eruption was observed on her face. The serum herpes zoster virus antibodies were confirmed within the normal range. Magnetic resonance imaging revealed no abnormalities. The authors suspected a right trigeminal neuropathy after vaccination. Administration of carbamazepine and pregabalin improved TN but facial numbness persisted, especially in the mandibular division. LESSONS: The coronavirus is a possible etiology of secondary trigeminal neuropathy in the case of MVD for TN.

Small vestibular schwannoma presented with trigeminal neuralgia: illustrative case.

BACKGROUND: A vestibular schwannoma (VS) presenting with paroxysmal facial electric shock pain, that is, trigeminal neuralgia (TN), is relatively rare. Furthermore, TN is extremely rare in small VSs. OBSERVATIONS: Herein, the authors report the case of a 52-year-old woman with a complaint of right TN. Magnetic resonance (MR) imaging revealed a right VS of 12-mm diameter that compressed the trigeminal nerve. Although she did not report any hearing impairment, audiometry revealed decreased high-frequency range on the right side. The tumor was excised using the right retrosigmoid approach, and TN was confirmed to be caused by direct compression of the trigeminal nerve by the VS. Sufficient decompression of trigeminal nerve was done. The proximity of the trigeminal nerve root to the vestibular nerve root was the cause of TN. TN disappeared immediately after surgery, and there was no worsening of hearing impairment and facial paralysis. LESSONS: It is important to remember that TN may occur with direct tumor compression, even in small VSs. A preoperative 3-dimensional MR cisternogram/angiogram fusion image clearly showed direct tumor compression of the trigeminal nerve and the absence of responsible vessels, which was useful for surgical planning.

Unruptured aneurysm at bifurcation of super short middle cerebral artery mimicking duplicated middle cerebral artery aneurysm.

Background: Duplicated middle cerebral artery (DMCA) is a normal variation of the middle cerebral artery (MCA), and distinguishing DMCA from other arteries based only on the angiographical findings is sometimes difficult. Case Description: Preoperative angiography of a 60-year-old woman revealed two MCAs originating near the top of the right internal carotid artery and a 6-mm-sized aneurysm located between these two MCAs. The ipsilateral A1 segment of the anterior cerebral artery was not visualized due to hypoplasia. The patient was diagnosed with an unruptured aneurysm at the bifurcation between MCA and DMCA, preoperatively. However, during clipping surgery, the hypoplastic A1 segment was observed at approximately 2 mm proximal to the bifurcation of the MCA, indicating that these two MCAs were not "true" MCA and DMCA, but rather two normal MCA trunks bifurcated from the very short prebifurcation segment of M1. This difference in interpretation was due to the fact that the hypoplastic A1 was not visualized on preoperative examinations. The patient was discharged following the surgery without any neurological deficits. Conclusion: The distinction between DMCA and MCA trunks from the very short prebifurcation segment of MCA might be difficult, especially when the ipsilateral A1 segment is hypoplastic. Such an M1 with a length of 2-3 mm might be named super short M1. Thus, it is necessary to confirm the anatomy during aneurysm surgery.

In vivo goat brain model for neurosurgical training.

Background: Novice neurosurgeons require neurosurgical technique training, but the current method is demanding and time consuming. Therefore, it is crucial to perform training using an appropriate and informative method. In this report, we describe our attempts to provide training in neurosurgical techniques using goat in vivo brain model and to demonstrate the effectiveness of this model. Methods: Under general anesthesia, the surgery was performed on a male goat in the prone position. A midline liner skin incision was made in the scalp, six burr holes were drilled, a craniectomy was performed, and the dura was incised in an arcuate fashion. We attempted the interhemispheric approach and a retrosigmoid approach. Results: It was confirmed that common neurosurgical approaches are achievable in this model. Furthermore, anatomical structures such as nerves and blood vessels were similar to those of humans. Moreover, the goat brain was similar in color and texture to that of humans. Conclusion: Unlike a cadaver brain, in vivo brain requires hemostasis and careful dissection, which provides the surgeons a realistic experience of actual neurosurgery.

Recanalization for straight sinus thrombosis through combined mechanical thrombectomy: A case report.

Background: Systemic anticoagulation has been the standard treatment for cerebral venous sinus thrombosis (CVT). Although endovascular treatments, including mechanical thrombectomy (MT), have been reported to be effective for CVT, no clear evidence has been established. Case Description: A 51-year-old woman who had been administered oral contraceptive pills was transferred to our hospital with altered consciousness and disorientation. Computed tomography (CT) revealed a hyperdense signal in the straight sinus (StS), and CT angiography revealed a defect in the basal vein and StS, leading to a diagnosis of StS thrombosis. Although systemic anticoagulation through unfractionated heparin was performed, her neurological condition deteriorated, and venous ischemia was observed on CT the next day. She then underwent MT. Partial recanalization was achieved with an aspiration catheter and a stent retriever. Her neurological condition improved tremendously, and venous ischemia was reversed following MT. She was discharged 3 weeks later without neurological deficits with oral anticoagulant. Conclusion: This was a relatively rare case with CVT confined to StS. Immediate combined MT for StS thrombosis can improve venous circulation, make the venous ischemia reversible, and improve patient outcomes, even if it results in partial recanalization.

Intermediate nerve neuralgia developed during hemifacial spasm follow-up: illustrative case.

BACKGROUND: Intermediate nerve neuralgia (INN) is a rare condition believed to be caused by vascular compression, with external auditory canal pain as the chief symptom. The authors reported a rare case of a 78-year-old woman who developed INN during follow-up for hemifacial spasm (HFS). OBSERVATIONS: The patient had been receiving Botox treatment for right HFS for 20 years when she developed paroxysmal electric shock pain in the right external auditory canal and tinnitus induced by opening her mouth. A three-dimensional magnetic resonance fusion image showed the cisternal portion of the facial-vestibulocochlear nerve complex to be compressed by the meatal loop of the anterior inferior cerebellar artery (AICA), which was pressed against by the posterior inferior cerebellar artery. The authors diagnosed INN, and microvascular decompression (MVD) was performed. Surgical findings were consistent with preoperative neuroimaging. In addition, the proximal portion of the meatal loop of the AICA had passed between the facial and vestibulocochlear nerves, compressing both. The AICA was moved and the nerve completely decompressed. All symptoms improved immediately following surgery. LESSONS: When INN occurs during HFS follow-up, aggressive MVD should be considered based on detailed neuroimaging. This treatment is a very effective single-stage cure for INN, HFS, and vestibulocochlear symptoms.

Anatomical Factors That Impede Using the Radial Artery Approach for Carotid Artery Revascularization.

OBJECTIVES: We investigated the anatomical characteristics that complicate utilizing the radial artery approach (RAA) for craniocervical intravascular intervention. METHODS: The data of 73 lesions in 65 consecutive patients who underwent transradial cervical carotid artery intervention was evaluated. We assessed the success rate of RAA in right-sided and left-sided lesions. The diameters and angles of the left and right common carotid arteries and the aortic, brachiocephalic, and right subclavian arteries, which constitute the paths of the guiding sheath, were assessed for each of the left- and right-sided lesions. RESULTS: It was difficult to apply RAA in 10 cases (13.7%), of which 2 (5.0%) involved right-sided and 8 (24.2%) left-sided lesions. The approach was significantly more difficult to perform in left-sided than in right-sided lesions (P = 0.02). Although the treatments were successfully completed, crossover to the femoral artery approach was required in 4 cases (5.5%, 2 cases for left-sided lesions). Placement of the guiding sheath in the common carotid artery was successful for all right-sided lesions; however, the guiding sheath slipped off to the aorta during stent advancement in 2 cases. When the angle between the brachiocephalic artery and aortic arch was small, the introduction of the guiding sheath to left-sided lesions was difficult in eight cases (P = 0.0001). CONCLUSIONS: RAA was difficult to perform in cases involving left-sided lesions and a small angle between the brachiocephalic artery and aortic arch. This study could help delineate the factors associated with difficulty of catheter introduction and instability of RAA.

Retrograde endovascular revascularization for chronic total occlusion of the internal carotid artery: a case report.

Endovascular revascularization of a chronically occluded internal carotid artery (ICA) is challenging because the occlusive segment can be long and tortuous. A case is presented of a successful recanalization of a chronically occluded ICA by retrograde passing of a guidewire from the intracranial ICA to the cervical ICA via the posterior communicating artery. This case suggests that a retrograde approach for reopening an occluded artery may be useful during neurovascular interventions, similar to percutaneous coronary interventions. In this patient, daily transient ischemic attacks disappeared after successful recanalization of the ICA.

A complete thrombotic large aneurysm at the nonbranching segment of the distal anterior cerebral artery mimicking a cavernous malformation: illustrative case.

BACKGROUND: Thrombotic aneurysms at the nonbranching segment of the distal anterior cerebral artery (ACA) are extremely rare and difficult to differentiate from cavernous malformations by radiographic features alone. OBSERVATIONS: Computed tomography and magnetic resonance imaging of a 30-year-old female patient with a chronic headache complaint revealed a 22-mm frontal lobe mass. The mass showed heterogeneous mixed intensity and hemosiderin deposits on magnetic resonance images. It was not visualized by conventional angiography, indicating that the mass and ACA/other vessels were not connected. The patient was preoperatively diagnosed with a cavernous malformation. However, during resection, the mass surface was white and smooth, different from a cavernous malformation. Although the mass was adherent to the pericallosal artery branch, no luminal continuity was observed. After detachment, the mass was completely resected. Pathological and immunohistochemical findings indicated a vessel wall and interior thrombus. The patient was rediagnosed with a thrombotic aneurysm at the distal ACA nonbranching segment and discharged 10 days postsurgery without neurological deficits. LESSONS: Because radiographic findings of thrombotic aneurysm and cavernous malformation are similar, mass lesions in contact with major arteries should be differentiated as thrombotic aneurysms, even when the artery lumen appears disconnected from the mass.

Unilateral C1 Posterior Arch Screw-C2 Laminar Screw Posterior Fixation for Vertebral Artery Preservation in Bow Hunter's Syndrome.

Pedicle or lateral mass screws, which are usually used to fix atlantoaxial instability, increase the risk of vertebral artery (VA) injury in patients with bone or arterial anomalies or osteoporotic bone. Here, we report the use of a unilateral C1 posterior arch screw-C2 laminar screw posterior fixation with a contralateral C1 lateral mass screw for VA preservation in a patient with bow hunter's syndrome (BHS). A 65-year-old male presented with recurrent loss of consciousness in the right rotational and backward-bending head positions for 1 year. Cerebral angiography in the same head position showed that the left VA was disrupted at C1/2 and the right VA was hypoplastic. The patient was diagnosed with BHS. C1-2 posterior fixation and iliac bone grafting were performed. The left VA was on the dominant side, and the VA was in a high position; thus, a C1 posterior arch screw was selected for the left side, a C1 lateral mass screw was selected for the right side, and a C2 laminar screw with O-arm navigation and a C-arm was used to prevent arterial injury. Intraoperative findings revealed no VA injury, and postoperative computed tomography showed the screw at the planned site. In a patient with BHS, posterior fixation with a unilateral C1 posterior arch screw-C2 laminar screw prevented VA injury because the screw could be inserted while avoiding the VA.

Use of flexible endoscopic aspiration for an intraventricular small floating clot with hemorrhage: a technical note.

BACKGROUND: Although flexible endoscopy is effective for intraventricular lesions, it is less frequently used for hemorrhagic cases. In some hemorrhagic strokes, blood clots may plunge into the cerebral aqueduct and cause acute obstructive hydrocephalus. A flexible endoscope can aspirate clots and prevent acute hydrocephalus. METHODS: Here, we report four cases of hemorrhage: one of intracerebral hemorrhage and three of subarachnoid hemorrhages. RESULTS: In all cases, acute hydrocephalus was not apparent upon admission. Sudden comatose occurred; computed tomography revealed acute obstructive hydrocephalus with a strangulated clot in the cerebral aqueduct. We performed aspiration of the strangulated clot using a flexible endoscope. Consciousness improved in all cases, and acute hydrocephalus was prevented in all cases. CONCLUSION: The use of simple flexible endoscopic aspiration for clots might be a beneficial and less-invasive procedure for acute obstructive hydrocephalus caused by a small clot with hemorrhagic stroke.