Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients.

PURPOSE: This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications. METHODS: This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods. RESULTS: Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%). CONCLUSIONS: From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Surgical Thromboendarterectomy for Free-Floating Thrombus Associated with Cervical Carotid Artery Dissection: A Case Report.

BACKGROUND: Free-floating thrombus (FFT) of the cervical carotid artery is a rare but critical condition leading to stroke. The most common underlying pathology is atherosclerotic plaque; nonatherosclerotic pathologies are much rarer. Here we report a case of FFT associated with cervical carotid artery dissection that was successfully treated by surgical thromboendarterectomy. METHODS: A 51-year-old man presented with headache, pain in the left neck, and amaurosis fugax. Magnetic resonance angiography revealed mild stenosis in the bifurcation of the left carotid artery. The stenotic lesion was considered as a possible dissection because of the normal appearance of the vessel 2 years ago and its clinical presentation. Oral aspirin was initiated with the diagnosis of transient ischemic attack. Two weeks later, ultrasound was planned for further examination, which demonstrated a massive FFT with intramural hematoma in the lesion. Because FFT was present despite taking aspirin, surgical thromboendarterectomy was performed to prevent further ischemic events. RESULTS: Intraoperative findings revealed that FFT was the thrombus protruding from the intramural hematoma caused by arterial dissection. After the whole dissected layer was removed, the residual lumen was reinforced by multiple tacking sutures to prevent recurrence of dissection. No further ischemic events and recurrence occurred during the 1-year of follow-up after the surgery. CONCLUSIONS: When managing patients with carotid artery dissection, the formation of FFT should be considered as a possible critical feature. Surgical thromboendarterectomy with intimal tacking sutures might be an option for the treatment, ensuring immediate, preventive effects against the risk of cerebral embolism.

[Surgical Results of Lumbar Degenerative Disease with Foot Drop].

Drop foot is associated with various diseases, such as peripheral nerve disease, lumbar degenerative disease, metabolic disease, and endocrine disease. Among lumbar degenerative diseases, lumbar disc herniation and lumbar canal stenosis are most commonly reported. We report the surgical outcomes of patients with drop foot caused by lumbar degenerative diseases. Between 2008 and 2018, we encountered 24 cases of drop foot in patients who underwent surgery of the lumbar lesion. The mean age was 69.5 years(49-88 years). Fourteen patients were male and ten were female. The mean time interval between the onset of drop foot and surgery was 51.5 days(from 7 days to 1 year). Drop foot, as a clinically significant muscle weakness, was defined at levels of manual muscle test(MMT)3 or lower. Responsible lesions for drop foot were canal stenosis at L4/5 in 8 cases, disc herniation at L4/5 in 10 cases, disc herniation at L5/S1 in 5 cases, and far-out syndrome in 1. One case involved drop foot bilaterally. Muscle weakness improved by surgery at levels of MMT 4 or greater in 16 cases(66.7%). Six cases of complete paresis or tibialis anterior muscle atrophy preoperatively resulted in no improvement;however, neuralgia was relieved in all. Twelve of 15 cases(80%)of lumbar disc herniation and 4 of 10 cases(40%)of lumbar canal stenosis resulted in improvement. Between disc herniation and canal stenosis, the surgical success rate was not statistically different. Age and the time interval between the onset and surgery were also not significant factors of the outcome. Surgical intervention seems to be beneficial even in cases of severe muscle weakness since pain relief can be expected, which leads to improvement in gait.

[Implementation of Penumbra-assisted Half-Stent Thrombectomy for Patients with Acute M2 Occlusion:Results of Initial Experiences].

The benefits of mechanical thrombectomy(MT)for acute M2 occlusion have remained unclear because of unavoidable device-related complications due to vascular morphological characteristics. We developed a Penumbra-assisted half-stent thrombectomy for achieving secure retrieval of thrombus with minimal damage to the small-caliber vessel. In total, 6 patients were treated with MT for acute M2 occlusion using this technique between November 2016 and May 2017, including 3 men and 3 women, mean age 74.8(51-98)years. The mean baseline National Institutes of Health Stroke Scale score was 17.5(6-32), and Alberta Stroke Program Early Computed Tomography Score-Diffusion-Weighted Imaging was 7.5(6-9). After navigation of the microcatheter through the thrombus in M2 supported by a Penumbra 4MAX as a distal access catheter, the stent retriever(SR)was partially deployed to cover the entire thrombus. The 4MAX was then advanced towards the caudal end of the thrombus, and the SR was pulled back into the 4MAX with simultaneous aspiration of the 4MAX. We used the Trevo XP3 in 5 patients and Revive SE in 1 patient. The mean procedure time from groin puncture to recanalization was 60(54-66)min. Successful recanalization(Thrombolysis in Cerebral Infarction score 2b or 3)was achieved in 5(83%)patients. There were no cases of symptomatic intracranial hemorrhage. Good outcome(modified Rankin Scale score 0 to 2)at 3 months was achieved in 3(50%)patients. Penumbra-assisted half-stent thrombectomy appears to be an effective alternative strategy in MT for acute M2 occlusion.

Specific protein-labeling and ligand-binding position analysis with amidopyrene probes as LDI MS tags.

To readily analyze the binding mode of protein-ligand interactions, we developed ligand-bound-type and ligand-dissociation-type probes having 6-amidopyrene (apy) as a detecting group. Matrix- and label-assisted laser desorption/ionization mass spectrometry (MALDI and LA-LDI MS) analyses and a covalent docking simulation using these probes precisely determined the binding position of the ligand biotin on the target protein avidin (RMSD = 0.786 and 0.332 Å). Our apy-probe-labeling method may be useful for determining the unknown ligand-binding sites of various target proteins.

[Two Cases of Bilateral Orbital Metastases of Breast Cancer].

Two cases of breast cancer with bilateral orbital metastases associated with intracranial metastases are presented. Case 1:A 61-year-old woman who was diagnosed with breast cancer 14 years earlier presented with rapid deterioration of visual acuity, eye pain, and limitation of left-sided extraocular motility. Magnetic resonance(MR)images showed an enhanced lesion in the left orbital apex, ethmoid sinus, and right middle fossa. The first gamma knife radiotherapy(35 Gy, 5 Fr)was performed successfully, but was followed by recurrence 18 months later in the right intraorbital, where newly formed iso-intensity masses in the extraconal compartment were found. The second gamma knife radiosurgery was performed for three masses(20 Gy). Case 2:A 35-year-old woman with breast cancer who was diagnosed 22 months earlier was treated for meningeal carcinomatosis by whole-brain radiation(30 Gy, 10 Fr)and intrathecal chemotherapy. Eight months later, swelling in both eyelids and limitation of extraocular motility developed rapidly. MR imaging revealed an infiltrating lesion in the cone with heterogenous signal that was encasing, but not infiltrating the optic nerves. The extraconal lesion extended into the soft tissue of the lower eye lid. She expired one week after diagnosis. With the increasing number of long-term survivors with breast cancer, intraorbital metastases may be found during the course of treatment for intracranial lesions. Understanding the unique clinical presentation and characteristic MR findings of this rare entity are emphasized.

Mechanical Thrombectomy for Acute Ischemic Stroke Patients Aged 80 Years or Older.

BACKGROUND: There are limited data about the prognostic factors predicting outcomes after mechanical thrombectomy with stent retrievers for the elderly. Here, we evaluated outcomes in elderly patients in a real-world setting. METHODS: Between April 2015 and January 2017, 80 patients with anterior intracranial acute large vessel occlusion, who had lived independently before ictus, were treated with mechanical thrombectomy using a stent retriever at our institute. We compared outcomes between patients ≥80 years old (n = 36) and those <80 years old (n = 44), and assessed prognostic factors for favorable outcomes (modified Rankin Scale score 0-2) at 90 days in all patients. RESULTS: There was no significant difference in baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early Computed Tomography Score between the 2 groups. Successful revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] scores 2b/3) (83% versus 93%, P = .286), complete recanalization (mTICI 3) (47% versus 50%, P = .826), and favorable outcomes (42% versus 57%, P = .261) were achieved more often in those <80 years old, but differences did not reach statistical significance. Multivariate regression analysis showed that baseline National Institutes of Health Stroke Scale (P = .013) and mTICI scores of 3 (P = .006) were significant predictive factors, but being ≥80 years old and baseline Alberta Stroke Program Early Computed Tomography Score were not. In those ≥80 years old, mTICI score of 3 was an influential factor for favorable outcome (P = .017). CONCLUSIONS: Being aged 80 years or older was not a significant predictor for outcomes after mechanical thrombectomy, whereas complete recanalization was an influential predictor of outcome in the elderly.

Anaplastic and meningothelial meningiomas in a single tumor: A "dedifferentiated meningioma"?

The patient was a 74-year-old man, who developed progressive cognitive impairment and gait instability. Neuroradiological examination demonstrated a large and predominantly extra-axial tumor spreading over the bilateral frontal base, indicative of olfactory groove meningioma. The greater part of the resected tumor consisted of a dense, patternless proliferation of large, round or polygonal cells, and compactly fascicular growth of spindle cells. Tumor cells showed markedly anaplastic cytological features. In small areas of the tumor, a typical meningothelial meningioma showing no cellular atypism was found. Both tumor components were closely juxtaposed and no pathological features of an intermediate grade (atypical meningioma) were noted. Shortly after the operation, the patient developed a local recurrence of the tumor and multiple metastases to the cerebrum, bone and skin. Anaplastic meningioma is a rare, highly malignant neoplasm which arises de novo or as a result of the progressive transformation of a low-grade meningioma. The coexistence of anaplastic and low-grade components in a single meningeal tumor has been rarely reported. This dimorphic appearance is reminiscent of "dedifferentiation", a phenomenon infrequently seen in various mesenchymal and salivary gland neoplasms. We think that the term "dedifferentiated meningioma" can be appropriately applied to tumors such as that reported herein.

[A Case of Spontaneous Cerebrospinal Fluid Leak Associated with Cervical Spondylosis].

Spontaneous cerebrospinal fluid leak and intracranial hypotension associated with cervical spondylosis have rarely been observed, and only a few cases are reported. A 69-year-old woman, previously treated for rectal and thyroid cancer, complained of a non-postural persistent headache. The patient regularly practiced aerobic exercise, but a month earlier she had started experiencing headache and neck pain while exercising. Computed tomography(CT)showed bilateral chronic subdural hematomas, and magnetic resonance imaging(MRI)revealed diffuse dural enhancement and tonsillar herniation. We drained the subdural hematomas and replaced the ventricular reservoir to safely access the cerebrospinal fluid space. After surgery, the persistent headache disappeared for several days, but a postural headache emerged. CT myelogram showed extradural accumulation of the contrast medium at the C2-5 level with cervical spondylosis. The patient was treated with conservative therapy of bed rest and intravenous fluid hydration for two weeks, and the headache improved. CT myelogram after treatment showed no extradural accumulation of the contrast medium. Spontaneous cerebrospinal fluid leak associated with cervical spondylosis could be induced by the repeated minor mechanical stress caused by physical exercise. Therefore, the possibility that non-postural persistent headache may be caused by spontaneous cerebrospinal fluid leak should not be underestimated.

[Association of Deep Venous Thrombosis with D-dimer Values in Patients with Hemorrhagic Stroke].

Pulmonary embolism(PE)in the early phase of stroke worsens the prognosis. It is necessary to detect deep venous thrombosis(DVT)to avoid PE. We conducted the D-dimer screening in order to detect DVT at an earlier stage. We retrospectively analyzed the clinical data of patients with hemorrhagic stroke who were admitted to the local stroke center, and investigated the complication rates of DVT, PE, D-dimer values, and risk factors of DVT. From October 2012 to August 2014, 261 patients were included. DVT was detected in 46 patients(17.6%)and anticoagulant therapy was started in 5 patients with central DVT. PE did not occur during this observation period. The D-dimer cutoff value for estimating the presence of the DVT was 8.9µg/mL, and the risk factors for DVT were older age, severe neurological disability, prolonged hospital stays, and subarachnoid hemorrhage. D-dimer screening is very useful to make earlier diagnosis and treatment of DVT.

Spleen serves as a reservoir of osteoclast precursors through vitamin D-induced IL-34 expression in osteopetrotic op/op mice.

Osteoclasts are generated from monocyte/macrophage-lineage precursors in response to colony-stimulating factor 1 (CSF-1) and receptor activator of nuclear factor-κB ligand (RANKL). CSF-1-mutated CSF-1(op/op) mice as well as RANKL(-/-) mice exhibit osteopetrosis (OP) caused by osteoclast deficiency. We previously identified RANKL receptor (RANK)/CSF-1 receptor (CSF-1R) double-positive cells as osteoclast precursors (OCPs), which existed in bone in RANKL(-/-) mice. Here we show that OCPs do not exist in bone but in spleen in CSF-1(op/op) mice, and spleen acts as their reservoir. IL-34, a newly discovered CSF-1R ligand, was highly expressed in vascular endothelial cells in spleen in CSF-1(op/op) mice. Vascular endothelial cells in bone also expressed IL-34, but its expression level was much lower than in spleen, suggesting a role of IL-34 in the splenic generation of OCPs. Splenectomy (SPX) blocked CSF-1-induced osteoclastogenesis in CSF-1(op/op) mice. Osteoclasts appeared in aged CSF-1(op/op) mice with up-regulation of IL-34 expression in spleen and bone. Splenectomy blocked the age-associated appearance of osteoclasts. The injection of 2-methylene-19-nor-(20S)-1α,25(OH)(2)D(3) (2MD), a potent analog of 1α,25-dihidroxyvitamin D(3), into CSF-1(op/op) mice induced both hypercalcemia and osteoclastogenesis. Administration of 2MD enhanced IL-34 expression not only in spleen but also in bone through a vitamin D receptor-mediated mechanism. Either splenectomy or siRNA-mediated knockdown of IL-34 suppressed 2MD-induced osteoclastogenesis. These results suggest that IL-34 plays a pivotal role in maintaining the splenic reservoir of OCPs, which are transferred to bone in response to diverse stimuli, in CSF-1(op/op) mice. The present study also suggests that the IL-34 gene in vascular endothelial cells is a unique target of vitamin D.

Fos plays an essential role in the upregulation of RANK expression in osteoclast precursors within the bone microenvironment.

Fos plays essential roles in the osteoclastic differentiation of precursor cells generated by colony-stimulating factor 1 (CSF-1) and receptor activator of NF-κB ligand (RANKL; also known as tumor necrosis factor ligand superfamily member 11, Tnsf11). RANKL-deficient (RANKL(-/-)) mice and Fos(-/-) mice exhibit osteopetrosis due to an osteoclast deficiency. We previously reported that RANK-positive osteoclast precursors are present in bone of RANKL(-/-) mice but not Fos(-/-) mice. Here we report the role of Fos in RANK expression in osteoclast precursors. Medullary thymic epithelial cells and intestinal antigen-sampling microfold cells have been shown to express RANK. High expression of RANK was observed in some epithelial cells in the thymic medulla and intestine but not in osteoclast precursors in Fos(-/-) mice. RANK mRNA and protein levels in bone were lower in Fos(-/-) mice than RANKL(-/-) mice, suggesting that Fos-regulated RANK expression is tissue specific. When wild-type bone marrow cells were inoculated into Fos(-/-) mice, RANK-positive cells appeared along bones. RANK expression in wild-type macrophages was upregulated by coculturing with RANKL(-/-) osteoblasts as well as wild-type osteoblasts, suggesting that cytokines other than RANKL expressed by osteoblasts upregulate RANK expression in osteoclast precursors. CSF-1 receptor-positive cells were detected near CSF-1-expressing osteoblastic cells in bone in Fos(-/-) mice. CSF-1 upregulated RANK expression in wild-type macrophages but not Fos(-/-) macrophages. Overexpression of Fos in Fos(-/-) macrophages resulted in the upregulation of RANK expression. Overexpression of RANK in Fos(-/-) macrophages caused RANKL-induced signals, but failed to recover the RANKL-induced osteoclastogenesis. These results suggest that Fos plays essential roles in the upregulation of RANK expression in osteoclast precursors within the bone environment.

[A case of possible immunoglobulin G4-related disease (IgG4-RD) with retroperitoneal fibrosis and central diabetes insipidus due to infundibulohypophysitis].

We report a case of possible immunoglobulin G4-related disease(IgG4-RD)that resulted in complications such as retroperitoneal fibrosis and infundibulohypophysitis. The patient was a 72-year-old male who presented with polyuria and polydipsia. Magnetic resonance imaging(MRI)revealed a thickened pituitary stalk and contrast enhancement with gadolinium. T1-weighted imaging revealed that the posterior pituitary high-signal zone had disappeared. Central diabetes insipidus was diagnosed on the basis of results of the hypertonic saline test. In addition, pressure due to retroperitoneal fibrosis resulted in hydronephrosis and elevated serum IgG4 levels. Because it was determined that the patient could have IgG4-RD, he was administered prednisolone, following which a decrease in the size of the pituitary stalk and retroperitoneal fibrosis was observed. IgG4-RD is characterized by elevated serum IgG4 levels and the infiltration of IgG4-positive plasma cells into various organs, including the central nervous system. Recently, IgG4-RD research teams organized by the Ministry of Health, Labour and Welfare established guidelines for the diagnosis of IgG4-RD. According to these guidelines, this case would fall under the category of "possible IgG4-RD." This case suggested that when infundibulohypophysitis is detected by neuroradiology, further investigation into the possibility of IgG4-RD should be recommended.

Endovascular Treatment of Tandem Atherosclerotic Cervical Internal Carotid Artery Occlusion in the Setting of Acute Ischemic Stroke.

BACKGROUND: Among tandem occlusions, atherosclerotic cervical internal carotid artery occlusion (ACICAO) can be technically challenging and associated with its unique complications. We evaluated our experience with endovascular treatment (EVT) of ACICAO in the setting of acute ischemic stroke. METHODS: In total, 154 consecutive patients who underwent EVT for acute anterior circulation stroke at our institute were retrospectively reviewed. Patients with tandem ACICAO were analyzed in this study. Procedures, recanalization rates, complications, and prognoses were evaluated. RESULTS: Ten patients (6%) of all 154 patients had ACICAO. In nine (90%) of the 10 patients, cervical lesions were successfully crossed and intervened upon. Four patients underwent stenting and five underwent angioplasty alone, followed by intracranial procedure. Eight patients (80%) achieved successful recanalization following mechanical thrombectomy for intracranial occlusion. However, one patient had massive subarachnoid hemorrhage during the procedure and another patient developed massive intracranial hemorrhage after EVT, both after stenting. Four of the five patients who initially underwent angioplasty alone subsequently underwent staged endarterectomy or stenting for residual stenosis on or after the next day. The single patient in whom the cervical lesion could not be crossed and another with reocclusion after EVT underwent a rescue bypass procedure due to persistent ischemic symptoms. After 90 days, four patients (40%) were functionally independent (modified Rankin scale score 0-2). CONCLUSIONS: Our experience suggests that EVT for ACICAO is technically feasible; however, it involves the potential risk of several significant complications. To avoid serious hemorrhagic complications, cervical lesions may be better treated with angioplasty alone first.

Mesenchymal cell TRPM7 expression is required for bone formation via the regulation of chondrogenesis.

Transient receptor potential melastatin-subfamily member 7 (TRPM7) is a bifunctional protein containing a kinase fused to an ion channel permeated with cations, including Ca2+ and Mg2+. Trpm7-null mice show embryonic lethality. Paired related homeobox 1 (Prx1) is expressed in undifferentiated mesenchymal cells such as the progenitor cells of both chondrocytes and osteoblasts involved in limb skeleton formation. Prx1-Cre-dependent Trpm7 mesenchymal-deleted mice were generated to examine the role of TRPM7 in bone development. We found that Prx1-Cre;Trpm7fl/fl mice had shortened bones and impaired trabecular bone formation. Trabecular bone parameters, such as the bone volume (BV/TV), and trabecular number (Tb.N), were decreased in Prx1-Cre;Trpm7fl/fl mice. The cortical bone parameters of cortical bone area (Ct.Ar) and cortical bone thickness (Ct.Th) were also down-regulated in these mice. The bone formation rate in Prx1-Cre;Trpm7fl/fl mice was unchanged, but the hypertrophic area and cell size of the zone were smaller, and the expression of Col2a1, Col10a1 and Mmp13 was downregulated compared with control mice. These findings suggest impaired chondrogenesis in Prx1-Cre;Trpm7fl/fl mice compared to control mice. The receptor activator of nuclear factor-kappa B ligand (RANKL) expression was increased, and RANKL-positive cells and osteoclasts were markedly accumulated in the boundary region between the growth plate and trabecular bone. In contrast, TRPM7 KR mice, which are kinase-dead mutants in which the TRPM7 ion channel function has not been altered, showed no marked differences in trabecular or cortical bone parameters compared to wild-type mice. These findings suggest that TRPM7 is critical as a cation channel rather than as a kinase in bone development via the regulation of chondrogenesis.

[Spontaneous occlusion of PICA-involved dissecting aneurysm with development of a collateral channel from the posterior meningeal artery].

A 53-year-old man suffered severe headache, which continued for three days. No abnormality was shown on CT scan, and a dissecting aneurysm of the right vertebral artery was suspected on MRI. Cerebral angiography revealed a dissection aneurysm of the right vertebral artery involved with the posterior inferior cerebellar artery (PICA) as pearl and string sign. The patient was conservatively managed under careful blood pressure control, and was followed by serial MRI. He presented with Wallenberg syndrome three weeks later. Second angiography revealed the occlusion of the PICA-involved dissecting aneurysm and the lateral medullary segment of the PICA supplied by a newly arising vessel from the right posterior meningeal artery (PMA). For the conservative treatment of a vertebral dissection aneurysm involved with PICA presenting with only pain, observation of the course by MRI was effective, and the PMA could develop as the collateral channel to the PICA territory.

Ligand-Dissociation-Type N,N-Dimethylaminopyrene Probes for In-Situ Site-Specific Protein Labeling.

To develop practical methods for in-situ labeling of target proteins and to analyze their binding modes with bioactive ligands, 6-N,N-dimethylaminopyrene-N-acyl-N-alkylsulfonamide-4,8-diazacyclononyne (dmpy-NASA-DACN) tags were synthesized. Strain-promoted azide-alkyne cyclization with azide-conjugated ligands (biotin and sulfonamide) gave ligand-dissociation-type dmpy probes. With these probes, specific labeling of avidin and human carboxylase 1 (hCA1) proceeded even in the presence of cell lysate proteins in ca. 10% RIPA buffer. Affinity purification, in-gel tryptic digestion on polystyrene gel, and MALDI MS analysis established the dmpy-labeled positions of target proteins. Molecular modeling studies also supported why the dmpy-labeling reactions proceeded site-specifically near ligand-binding sites on the target proteins. Our findings might contribute to the development of chemical probes that specifically label various biomacromolecules in cells.

Symptomatic Intracranial Artery Stenosis Due to an Unknown Embolus Following Cardiac Surgery: A Case Report.

Intracranial artery occlusion due to a foreign body is a complication associated with cardiac surgery that is treated by various techniques. However, little is known about appropriate strategies for symptomatic intracranial artery stenosis due to an unknown embolic source. We reported a case of middle cerebral artery (MCA) stenosis after mitral valve repair (MVR) for infective endocarditis (IE). An 80-year-old man presented with right hemiplegia. MR angiography findings were normal, and diffusion-weighted imaging revealed subtle ischemic change in the left MCA territory. The patient was diagnosed with cardioembolic stroke owing to IE and performed MVR. Four days later, he suddenly presented with consciousness disorder and left hemiplegia. Computed tomography (CT) confirmed a very low-density area within the right MCA. MR angiography revealed right MCA stenosis, which corresponded to the low-density area on CT images. Diffusion-weighted imaging revealed new ischemic change in the right MCA territory. Angiography confirmed an irregular stenosis at the right M2 with antegrade blood flow, and the hemiplegia resolved during angiography. Conservative therapy was performed; however, the resting 123 I-IMP-single photon emission CT revealed moderate perfusion defect in the right MCA territory, and transient left hemiplegia appeared every few days. Therefore, 19 days after the initial transient ischemic attack, the patient was performed superficial temporal artery-MCA anastomosis, and the patient responded with a good clinical course without recurrence of the ischemic symptoms. This strategy may be a safe and effective treatment for symptomatic intracranial artery stenosis due to an unknown embolic source.

Iatrogenic intracranial vessel dissection during mechanical thrombectomy rescued by emergent stenting: 2 case reports.

Intracranial vessel dissection is a procedural complication associated with endovascular treatment. However, there have been few reports on its potential causes and management during mechanical thrombectomy. In approximately 250 cases of mechanical thrombectomy over the past 5 years at our institution, iatrogenic intracranial dissection occurred in 2 patients (0.8%). In this report, we described these 2 cases that were rescued through emergent stenting. Mechanical thrombectomy, using both a stent retriever and an aspiration catheter, was performed for acute middle cerebral artery M2 occlusion in Patient 1 (a 69-year-old man) and for distal M1 occlusion in Patient 2 (an 83-year-old woman). In both cases, recanalization was achieved with the procedure, but irregular stenosis developed at the initially nonoccluded, but mildly arteriosclerotic, M1, after recanalization. During the thrombectomy procedure, the aspiration catheter sifted up to the arteriosclerotic M1. In both cases, the lesions were considered vessel dissection, due to a shift of the aspiration catheter tip into the arteriosclerotic vessel wall. Repeated percutaneous angiography with antithrombotic therapy failed to improve the lesions and to maintain the antegrade blood flow. Finally, lesions in each patient were successfully rescued through the use of emergent stenting. A drug-eluting stent for coronary use was deployed in Patient 1, and an Enterprise stent was applied in Patient 2. Inadvertent shift of the aspiration catheter into arteriosclerotic vessels can cause a serious intracranial vessel dissection. When performing mechanical thrombectomy, intracranial stents need to be available as rescue treatment devices to manage refractory iatrogenic intracranial vessel dissection.