Ventriculoperitoneal shunt infection and malfunction in adult patients: incidence, risk factors, and long-term follow-up of single institution experience.

Ventriculoperitoneal shunt surgery was developed to manage excessive cerebrospinal fluid (CSF) in the brain's ventricles and is considered a mainstream treatment. Despite the development of the shunt device system, various complications still occur. In this study, we reported 307 cases and a long-term follow-up of at least five years of adult patients who underwent VP shunt surgery and analyzed various factors that may affect revision surgery. A retrospective study was conducted at Asan Medical Center, Korea, a tertiary medical center. We reviewed 307 cases from January 2012 to December 2018. The patients' neurological status, predisposing medical conditions, laboratory findings, and other operation-related factors were reviewed using electrical medical records. The normal function group comprised 272 cases (88.6%), and the overall incidence of revision group comprised 35 cases (11.4%). Of the 35 revision surgery cases, 30 (85.71%) were due to shunt malfunctions, such as obstruction, overdrainage, and valve-related errors while 5 (14.29%) were due to shunt infection. Patient demographics, mental status, and operation time did not influence revision as risk factors. Serum laboratory findings showed no statistical difference between the two groups. The white blood cell (WBC) count in the CSF profile differed significantly between the two groups. The Hakim Programmable valve (Codman, USA) is mainly used in our center. In addition, various shunt systems were used, including Strata Regulatory valve (Medtronic, USA), proGAV (Aesculap, USA), and Accu-Flo (Codman, USA). This study analyzed the factors affecting long-term outcomes. Based on these findings, efforts are needed to achieve more favorable outcomes in the future.

Risk of Cerebral Aneurysm Rupture After Liver Transplantation: Development and Validation of a Hemorrhagic Stroke Scoring Model.

BACKGROUND: Liver transplantation (LT) patients appear to be more prone to neurological events compared to individuals undergoing other types of solid-organ transplantation. The aims of the present study were to analyze the prevalence of unruptured intracranial aneurysms (UIAs) in patients undergoing liver transplantation (LT) and to examine the perioperative occurrence of subarachnoid hemorrhage (SAH). Also, it intended to systematically identify the risk factors of SAH and hemorrhagic stroke (HS) within a year after LT and to develop a scoring system which involves distinct clinical features of LT patients. METHODS: Patients who underwent LT from January 2012 to March 2022 were analyzed. All included patients underwent neurovascular imaging within 6 months before LT. We conducted an analysis of prevalence and radiological features of UIA and SAH. The clinical factors that may have an impact on HS within one year of LT were also reviewed. RESULTS: Total of 3,487 patients were enrolled in our study after applying inclusion and exclusion criteria. The prevalence of UIA was 5.4%. The incidence of SAH and HS within one year following LT was 0.5% and 1.6%, respectively. We developed a scoring system based on multivariable analysis to predict the HS within 1-year after LT. The variables were a poor admission mental status, the diagnosis of UIA, serum ammonia levels, and Model for End-stage Liver Disease (MELD) scores. Our model showed good discrimination among the development (C index, 0.727; 95% confidence interval [CI], 0.635-0.820) and validation (C index, 0.719; 95% CI, 0.598-0.801) cohorts. CONCLUSION: The incidence of UIA and SAH was very low in LT patients. A poor admission mental status, diagnosis of UIA, serum ammonia levels, and MELD scores were significantly associated with the risk of HS within one year after LT. Our scoring system showed a good discrimination to predict the HS in LT patients.

The risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms: anatomical consideration and infarction territory.

PURPOSE: An anterior communicating artery is a common location for both ruptured and unruptured intracranial aneurysms, and microsurgery is sometimes necessary for their successful treatment. However, postoperative infarction should be considered during clipping due to the complex surrounding structures of anterior communicating artery aneurysms. This study aimed to evaluate the risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms and its clinical outcomes. METHODS: The data of patients who underwent microsurgical clipping of an unruptured anterior communicating artery aneurysm in our hospital between January 2008 and December 2020 were retrospectively analyzed. The patients' demographic data, anatomical features of the anterior communicating artery complex and aneurysm, surgical technique, characteristics of postoperative infarction, and its clinical course were evaluated. RESULTS: Notably, among 848 patients, 66 (7.8%) and 34 (4%) patients had radiologic and symptomatic infarctions, respectively. Univariate and multivariate logistic regression analyses showed that hypertension (odds ratio (OR), 1.99; [Formula: see text]), previous stroke (OR, 3.89; [Formula: see text]), posterior projection (OR, 5.58; [Formula: see text]), aneurysm size (OR, 1.17; optimal cut-off value, 6.14 mm; [Formula: see text]), and skull base-to-aneurysm distance (OR, 1.15; optimal cut-off value, 11.09 mm; [Formula: see text]) were associated with postoperative infarction. In the pterional approach, a closed A2 plane was an additional risk factor (OR, 1.88; [Formula: see text]). Infarction of the subcallosal and hypothalamic branches was significantly associated with symptomatic infarction ([Formula: see text]). CONCLUSION: Hypertension, previous stroke, posteriorly projecting aneurysms, aneurysm size, and highly positioned aneurysms are independent risk factors for postoperative infarction during surgical clipping of an unruptured anterior communicating artery aneurysm. Additionally, a closed A2 plane is an additional risk factor of postoperative infarction in patients undergoing clipping via the pterional approach.

Efficacy of Acetylcysteine and Selenium in Aneurysmal Subarachnoid Hemorrhage Patients: A Prospective, Multicenter, Single Blind Randomized Controlled Trial.

BACKGROUND: Subarachnoid hemorrhage (SAH) patients have oxidative stress results in inflammation, tissue degeneration and neuronal damage. These deleterious effects cause aggravation of the perihematomal edema (PHE), vasospasm, and even hydrocephalus. We hypothesized that antioxidants may have a neuroprotective role in acute aneurysmal SAH (aSAH) patients. METHODS: We conducted a prospective, multicenter randomized (single blind) trial between January 2017 and October 2019, investigating whether antioxidants (acetylcysteine and selenium) have the potential to improve the neurologic outcome in aSAH patients. The antioxidant patient group received antioxidants of acetylcysteine (2,000 mg/day) and selenium (1,600 µg/day) intravenously (IV) for 14 days. These drugs were administrated within 24 hours of admission. The non-antioxidant patient group received a placebo IV. RESULTS: In total, 293 patients were enrolled with 103 patients remaining after applying the inclusion and exclusion criteria. No significant differences were observed in the baseline characteristics between the antioxidant (n = 53) and non-antioxidant (n = 50) groups. Among clinical factors, the duration of intensive care unit (ICU) stay was significantly shortened in patients who received antioxidants (11.2, 95% confidence interval [CI], 9.7-14.5 vs. 8.3, 95% CI, 6.2-10.2 days, P = 0.008). However, no beneficial effects were observed on radiological outcomes. CONCLUSION: In conclusion, antioxidant treatment failed to show the reduction of PHE volume, mid-line shifting, vasospasm and hydrocephalus in acute SAH patients. A significant reduction in ICU stay was observed but need more optimal dosing schedule and precise outcome targets are required to clarify the clinical impacts of antioxidants in these patients. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004628.

Probing the optical near-field of plasmonic nano structure using scanning thermal microscopy.

Scanning thermal microscopy (SThM) enables to obtain thermal characteristic information such as temperature and thermal conductivity from the signals obtained by scanning a thermometer probe over a sample surface. Particularly, the precise control of the thermometer probe makes it possible to study near-field radiative heat transfer by measuring the near-field thermal energy, which implies that when light is used as a local heat source, photothermal energy can be detected from the optical near-field by approaching the probe in the near-field region. In this study, SThM is applied to generate sub-wavelength near-field optical image in the plasmonic grating coupler. Herein, by controlling the surface plasmon polariton generation, we show that the dominant component of SThM signal is from the optical response rather than the thermal response. The obtained near-field optical images have a spatial resolution of 40 nm and signal to noise ratio of up to 19.8. In addition, field propagation images in theZ-direction can be visualised with the precise control of the distance between the thermometer probe and the sample.

Premammillary artery infarction after microsurgical clipping of unruptured posterior communicating artery aneurysm: risk factors and surgical and anatomical considerations.

Posterior communicating artery (PCoA) aneurysm is common and sometimes requires microsurgery; however, as data on premammillary artery (PMA) infarction after clipping is scarce, we retrospectively reviewed cases of post-clipping PMA infarction to analyze incidence, independent risk factors of infarction, and anatomical considerations. Data from 569 consecutive patients who underwent microsurgical clipping for unruptured PCoA aneurysm between January 2008 and December 2020 were included. Patients were categorized into the normal or the PMA infarction group. Statistical analyses and comparisons between the two groups were used to determine the influence of various factors. The normal group included 515 patients while the PMA infarction group had 31. The mean length of hospital stay was significantly longer in the PMA infarction group (10.3 ± 9.1 days) than in the normal group (6.5 ± 6.4 days; p < 0.0001). The distribution of Glasgow Outcome Scale at discharge was significantly different between the two groups (p ≤ 0.0001) but was not so at 6 months after discharge (p = 0.0568). Multivariate logistic regression analysis identified aneurysm size (odds ratio [OR], 1.194; 95% confidence interval [CI], 1.08-1.32; p = 0.0005) and medial direction of aneurysm (OR, 4.615; 95% CI, 1.224-17.406; p = 0.0239) as independent risk factors of post-clipping PMA infarction. Surgeons must beware of PMA infarction after clipping of large aneurysms that are medial in direction. Intraoperative verification of the patency of the PCoA and the PMA from various angles using various intraoperative methods can reduce morbidity due to PMA infarction.

Reactive Oxygen Species Scavenger in Acute Intracerebral Hemorrhage Patients: A Multicenter, Randomized Controlled Trial.

[Figure: see text].

Prevalence of cerebrovascular diseases that can cause hemorrhagic stroke in liver transplantation recipients: a 6-year comparative study with 24,681 healthy adults.

BACKGROUND AND PURPOSE: Cerebrovascular diseases are a leading cause of mortality after liver transplantation (LT). The prevalence of potentially hemorrhagic cerebrovascular diseases (HCVDs) that could cause a hemorrhagic stroke in patients with severe liver diseases has not been reported. We aimed to analyze the underlying prevalence of HCVDs that could lead to hemorrhagic strokes in LT recipients compared with that in previously healthy controls. METHODS: A retrospective study with 1,920 consecutive LT recipients and 24,681 adults who underwent a health checkup during the same period was conducted (January 2011-December 2016). The prevalence of cerebral aneurysms (CA), cerebral arteriovenous malformation (AVM), and cavernous malformation (CM) was evaluated using brain imaging, including computed tomography angiography, magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography. RESULTS: The prevalence of CA and CM were 3.1% and 0.5%, respectively, in the LT group and 3.8% and 0.4%, respectively, in the control group. According to the location of the cerebral artery, paraclinoid internal carotid artery aneurysms (odds ratio [OR] 0.440; P = 0.009) had a lower prevalence in LT recipients than in healthy controls. Anterior communicating artery (OR 3.080; P = 0.002) and superior cerebellar artery (OR 8.767; P = 0.017) aneurysms had a higher prevalence in the LT group than in the control. The prevalence of AVM was significantly higher in LT recipients (0.26%) than in healthy controls (0.06%). CONCLUSION: LT recipients showed a different distribution of CA prevalence according to the locations of the cerebral artery and had a higher overall prevalence of AVM than previously healthy controls.

Clinical features of ischemic complications after unruptured middle cerebral artery aneurysm clipping: patients and radiologically related factors.

Postoperative ischemic complication results in neurological sequelae and longer hospitalization after unruptured middle cerebral artery (MCA) aneurysm clipping surgery. We evaluated the radiological and patient-related factors associated with ischemic complications after unruptured MCA aneurysm clipping surgery. Patient demographics, radiological findings, and intraoperative factors were compared between patients with and without postoperative ischemic complications. The clinical courses and outcomes of postoperative ischemic complications were compared according to the types of ischemic complication. Forty-two out of 2227 patients (1.9%) developed postoperative ischemic complications after MCA aneurysm clipping. Multivariate analysis revealed that diabetes mellitus (DM) was a patient-related factor. Intraarterial (IA) calcification of the distal internal carotid artery (ICA), preoperative M1 stenosis, and M1 aneurysm were radiological factors that increased the risk of postoperative ischemic complications. DM was significantly associated with divisional branch territory infarction (P = 0.04). The time to first presentation of ischemic complication was significantly longer in divisional branch territory infarction than perforator territory infarction (67.8 ± 75.9 h vs. 22 ± 20.7, P = 0.023). Twelve out of 42 patients with ischemic complications (28.6%) had unfavorable outcome (mRS > 3). Perforator territory infarction was significantly associated with an unfavorable outcome (mRS > 3, P = 0.019). IA calcification of the distal ICA, M1 stenosis and aneurysms, and DM were significantly associated with postoperative ischemic complications after unruptured MCA aneurysm clipping. Patients with DM should be closely monitored postoperatively to detect delayed occurrence of divisional branch infarction. Trial registration number: 2019-1002, Date of registration: January 1, 2005, "retrospectively registered".

Scalp thickness as a predictor of wound complications after cerebral revascularization using the superficial temporal artery: a risk factor analysis.

OBJECTIVE: Cerebral revascularization using the superficial temporal artery diverts some of the blood supply from the scalp to the brain. This may compromise the blood supply to the scalp and could result in more wound complications. OBJECTIVE: This retrospective chart review aimed to identify the incidence of, and independent risk factors for, wound complications after cerebral revascularization using the superficial temporal artery. METHODS: Patients who underwent cerebral revascularization using the superficial temporal artery between January 2003 and February 2017 were studied. Minor wound complications included superficial skin necrosis, and mild wound dehiscence, while major wound complications included full-thickness skin necrosis, deep infection, and osteomyelitis that required additional surgical treatment. RESULTS: A total of 482 cerebral revascularization procedures using the superficial temporal artery were included. Wound complications developed in 32 cases (6.6% of the total), including 7 classified as major in severity (1.5% of the total). The multivariate analysis revealed diabetes mellitus (odds ratio 4.058, p = 0.001), low body mass index (odds ratio 1.21, p = 0.009), and thin scalp (odds ratio 1.82, p < 0.001) as the main risk factors for wound complications. Every 1-mm increase in scalp thickness was associated with a protective effect on wound complications (odds ratio 0.549). CONCLUSION: Cerebral revascularization using the superficial temporal artery was associated with a relatively high incidence of wound complications. Diabetes mellitus, low body mass index, and thin scalp were found to be independent risk factors for wound complications. The thickness of the scalp could be a useful predictor of wound complications.

The potential theragnostic (diagnostic+therapeutic) application of exosomes in diverse biomedical fields.

Exosomes are membranous vesicles of 30-150 nm in diameter that are derived from the exocytosis of the intraluminal vesicles of many cell types including immune cells, stem cells, cardiovascular cells and tumor cells. Exosomes participate in intercellular communication by delivering their contents to recipient cells, with or without direct contact between cells, and thereby influence physiological and pathological processes. They are present in various body fluids and contain proteins, nucleic acids, lipids, and microRNAs that can be transported to surrounding cells. Theragnosis is a concept in next-generation medicine that simultaneously combines accurate diagnostics with therapeutic effects. Molecular components in exosomes have been found to be related to certain diseases and treatment responses, indicating that they may have applications in diagnosis via molecular imaging and biomarker detection. In addition, recent studies have reported that exosomes have immunotherapeutic applications or can act as a drug delivery system for targeted therapies with drugs and biomolecules. In this review, we describe the formation, structure, and physiological roles of exosomes. We also discuss their roles in the pathogenesis and progression of diseases including neurodegenerative diseases, cardiovascular diseases, and cancer. The potential applications of exosomes for theragnostic purposes in various diseases are also discussed. This review summarizes the current knowledge about the physiological and pathological roles of exosomes as well as their diagnostic and therapeutic uses, including emerging exosome-based therapies that could not be applied until now.

Small versus Large Ruptured Intracranial Aneurysm: Concerns with the Site of Aneurysm.

BACKGROUND: Although size is one of the strongest predictors, small aneurysms often rupture. We compared the characteristics of small and large ruptured intracranial aneurysms (RIAs) according to their location to find the factors associated with small RIAs in each location. METHODS: Patients with subarachnoid hemorrhage due to saccular RIAs were consecutively enrolled. The sizes were dichotomized as small (<5 mm) or large, and the location was classified as paraclinoid-distal internal carotid artery, sidewalls of anterior or middle cerebral artery (MCA; sidewall), MCA-bifurcation, anterior or posterior communicating artery (Acom or Pcom, respectively), and posterior circulation RIAs. Independent factors associated with small RIAs compared to large RIAs were investigated in each location. RESULTS: Small RIAs were observed in 384 of 791 patients (48.5%), and were most commonly located at Acom (17.1%) followed by Pcom (9.0%) and sidewalls (7.2%). Female sex (OR 3.038; 95% CI 2.099-4.395), young age (OR 0.971; 95% CI 0.958-0.985), hypertension (OR 1.412; 95% CI 1.033-1.930) and multiple aneurysms (OR 1.942; 95% CI 1.335-2.824) were associated with small RIAs. By location, sidewall aneurysms (OR 2.183; 95% CI 1.049-4.542) were associated with small RIAs, whereas MCA-bifurcation (OR 0.318; 95% CI 0.168-0.599) and Pcom aneurysms (OR 0.511; 95% CI 0.277-0.944) were associated with large RIAs. The presence of multiple aneurysms (OR 4.69; 95% CI 1.45-21.19) was associated with small RIAs at sidewalls, and young age, female sex, hypertension and the presence of bilateral A1 (OR 1.85; 95% CI 1.09-3.13) were associated with small RIAs at Acom. Acom RIAs with bilateral A1 was smaller than those with unilateral A1 (4.7 ± 2.1 vs. 5.8 ± 2.6 mm; p < 0.001). CONCLUSIONS: Intracranial aneurysms which rupture below 5 mm are not uncommon, and the factors associated with small-sized RIAs differ according to location. Sidewall aneurysms, with multiple aneurysms and Acom aneurysms with bilateral A1 may rupture even at small size.

C4/5 foraminal stenosis predicts C5 palsy after expansive open-door laminoplasty.

INTRODUCTION: Laminoplasty is frequently performed in cervical myelopathy patients, but can lead to unexpected postoperative C5 palsy. Although several studies have examined the pathogenesis and prevention of postoperative C5 palsy, many controversies remain and some radiological findings identified as risk factors were not correlated with our outcomes. PURPOSE: This study sought reliable radiological findings that predict C5 palsy after laminoplasty and examined why the predictors of C5 palsy did not apply in our series. METHODS: This study reviewed 116 patients who underwent open-door laminoplasty for cervical spondylotic myelopathy between January 2014 and April 2016, retrospectively. C5 palsy was defined as weakness of the deltoid muscle. We evaluated the incidence of C5 palsy, the preoperative C2-7 Cobb's angle, and Pavlov ratio at the C4/C5 level using simple cervical lateral radiographs. We also evaluated the existence of an ossified posterior longitudinal ligament, the transverse diameter of the C4/5 foramen, and increases in the anteroposterior diameter of the spinal canal at the C4/5 levels after surgery. Furthermore, a high signal intensity on T2-weighted images of the cervical spinal cord preoperatively was noted. RESULTS: Of the 116 patients, 16 cases were excluded and 100 cases were analyzed; postoperative C5 palsy occurred in 8 patients (8%). There were no significant differences between the two groups except the average diameter of the C4/5 foramen. A diameter of the C4/5 foramen of less than 2 mm was significantly related to C5 palsy in the binary logistic regression test. CONCLUSIONS: A smaller diameter of the C4/5 foramen was the only factor significantly correlated with C5 palsy after laminoplasty. The results suggest that C4/5 foraminal stenosis is one of the best predictors of C5 palsy, which might be related to ischemic/reperfusion injury of the C5 root nerve after laminoplasty.

Development of Three-Dimensional Dental Scanning Apparatus Using Structured Illumination.

We demonstrated a three-dimensional (3D) dental scanning apparatus based on structured illumination. A liquid lens was used for tuning focus and a piezomotor stage was used for the shift of structured light. A simple algorithm, which detects intensity modulation, was used to perform optical sectioning with structured illumination. We reconstructed a 3D point cloud, which represents the 3D coordinates of the digitized surface of a dental gypsum cast by piling up sectioned images. We performed 3D registration of an individual 3D point cloud, which includes alignment and merging the 3D point clouds to exhibit a 3D model of the dental cast.

Deficiency of endothelium-specific transcription factor Sox17 induces intracranial aneurysm.

BACKGROUND: Intracranial aneurysm (IA) is a common vascular disorder that frequently leads to fatal vascular rupture. Although various acquired risk factors associated with IA have been identified, the hereditary basis of IA remains poorly understood. As a result, genetically modified animals accurately modeling IA and related pathogenesis have been lacking, and subsequent drug development has been delayed. METHODS AND RESULTS: The transcription factor Sox17 is robustly expressed in endothelial cells of normal intracerebral arteries. The combination of Sox17 deficiency and angiotensin II infusion in mice induces vascular abnormalities closely resembling the cardinal features of IA such as luminal dilation, wall thinning, tortuosity, and subarachnoid hemorrhages. This combination impairs junctional assembly, cell-matrix adhesion, regeneration capacity, and paracrine secretion in endothelial cells of intracerebral arteries, highlighting key endothelial dysfunctions that lead to IA pathogenesis. Moreover, human IA samples showed reduced Sox17 expression and impaired endothelial integrity, further strengthening the applicability of this animal model to clinical settings. CONCLUSIONS: Our findings demonstrate that Sox17 deficiency in mouse can induce IA under hypertensive conditions, suggesting Sox17 deficiency as a potential genetic factor for IA formation. The Sox17-deficient mouse model provides a novel platform to develop therapeutics for incurable IA.

Differences in the Postoperative Outcomes According to the Primary Treatment Options Chosen by Patients With Carpal Tunnel Syndrome: Conservative Versus Operative Treatment.

PURPOSE: We prospectively analyzed the differences in the preoperative status and final outcomes between patients with or without the motivation for prompt surgery after a recent diagnosis of carpal tunnel syndrome (CTS). METHODS: One hundred fifty-six patients were enrolled and followed up from a cohort of 220 patients who were diagnosed with CTS between 2011 and 2013. Basic demographic factors, including the occupational features, were investigated in group 1 (n = 52, conservative treatment followed by surgery) and group 2 (n = 100, surgery immediately after diagnosis). The preoperative electrodiagnosis, clinical items by Graham, Disabilities of the Arm, Shoulder, and Hand (DASH) outcomes questionnaire, Boston Carpal Tunnel Questionnaire scores, and grip/pinch strengths were evaluated, and the degree of improvements was compared. RESULTS: The onset period of the symptoms or signs, as well as the time from the diagnosis to surgery, was significantly longer in group 1 than in group 2. In group 1, nonprofessional, simple, and repetitive jobs were more prevalent; however, the professional category was more common in group 2. The preoperative distributions among the electrodiagnostic grades were not different in both groups. Most of the clinical items by Graham were more definitively improved in group 2. DASH improvement at the final follow-up was meaningfully more in group 2 (34 ± 5.3) than in group 1 (29 ± 6.5). Boston Carpal Tunnel Questionnaire showed a similar trend regarding the DASH score (preoperative, improvement at the final follow-up) with statistical significance. The increase in grip/pinch strength was also greater in group 2. CONCLUSIONS: Most patients, who refused/delayed surgery as the initial treatment for CTS, were not improved by conservative options. Eventually, carpal tunnel release was performed; however, the overall outcomes were inferior compared with those of the groups who agreed to operative treatment as the initial option.

Relationship of cubitus varus and ulnar varus deformity in supracondylar humeral fractures according to the age at injury.

BACKGROUND: We investigated the relationships of ulnar varus deformity and the degree of cubitus varus according to the age at injury in patients with cubitus varus. METHODS: Basic demographic factors were investigated in group 1 (injured at age younger than 5 years) and group 2 (injured at age 5-10 years). The uninjured side ulnar angle (UA) at the time of injury and final follow-up and the humeral-elbow-wrist angle (HEW-A) at final follow-up were measured. ΔUA (injured side - uninjured side UA at final follow-up) and ΔHEW-A (injured side - uninjured side HEW-A at final follow-up) were calculated and compared between the 2 groups. The correlation between ΔUA and ΔHEW-A was analyzed, and the degree of correlation was compared between the groups. RESULTS: Final UA and HEW-A on the injured side were increased more in group 1. ΔUA and ΔHEW-A were also more definitive in group 1. Positive correlations were found in both groups between ΔUA and ΔHEW-A, and the degree of correlation was similar in both groups. Distinct negative correlations were observed in both groups between the uninjured side UA at the time of injury and the ΔUA, but the degree of correlation differed significantly. CONCLUSIONS: The degree of ulnar varus correlated well with the degree of cubitus varus. A straighter ulna at the time of injury could become more bowed if cubitus varus deformity occurred and progressed. This may be evidence suggesting that the earlier correction of cubitus varus would be more effective under a less deformed varus of the ulna. LEVEL OF EVIDENCE: Level III; Retrospective Cohort Design; Treatment Study.

Optical field enhancement of nanometer-sized gaps at near-infrared frequencies.

We report near-field and far-field measurements of transmission through nanometer-sized gaps at near-infrared frequencies with varying the gap size from 1 nm to 10 nm. In the far-field measurements, we excluded direct transmission on the metal film surface via interferometric method. Kirchhoff integral formalism was used to relate the far-field intensity to the electric field at the nanogaps. In near-field measurements, field enhancement factors of the nanogaps were quantified by measuring transmission of the nanogaps using near-field scanning optical microscopy. All the measurements produce similar field enhancements of about ten, which we put in the context of comparing with the giant field enhancements in the terahertz regime.

Selective electric and magnetic sensitivity of aperture probes.

We report the effect of geometrical factors governing the polarization profiles of near-field scanning optical microscope (NSOM) probes. The most important physical parameter controlling the selective electric or magnetic field sensitivity is found to be the width of the metal rim surrounding aperture. Probes with metal rim width w < λ/2 selectively senses the optical electric field, while those with w > λ/2 selectively senses the optical magnetic field. Intensity variation of optical Hertz standing wave formed upon reflection at oblique incidence shows a phase difference of π/2 between electric and magnetic probes: an analogue of the classical Wiener's experiment. Our work paves way towards electromagnetic engineering of nanostructures.

Results of re-exploration because of compromised distal blood flow after clipping unruptured intracranial aneurysms.

BACKGROUND: One of the major causes for performing unplanned re-exploration of a craniotomy after microsurgery for unruptured intracranial aneurysms (UIAs) is compromised distal blood flow after clipping. Therefore, it is important to identify the causes of compromised distal blood flow after clipping and the factors that influence the prognosis for re-exploration in order to decrease ischemic complications related to clipping UIAs. METHOD: Between January 2007 and December 2013, 1954 patients underwent microsurgery for UIAs. In this cohort, 20 patients (1.0%) required unplanned re-exploration of the craniotomy for several reasons, and 11 patients (0.6%) underwent unplanned re-exploration with clip repositioning or changing of the previous clip because of compromised distal blood flow after clipping. Patient characteristics, aneurysm properties, intraoperative findings, annual incidence and prognosis were analyzed in these 11 patients. RESULTS: The annual incidence of re-exploration has gradually decreased since the introduction of several intraoperative monitoring techniques. In total, 3.0% of UIAs in the M1 trunk, 0.8% of UIAs at the origin of the anterior choroidal artery (AchA) and 0.5% of UIAs at the bifurcation of the middle cerebral artery (MCA) required re-exploration. Here, all 11 UIAs had broad necks, and atherosclerosis was identified around 10 UIAs. Six patients with compromised MCA flow demonstrated relatively better outcomes following re-exploration than five patients with a compromised lenticulostriate artery (LSA) or AchA flow. Four patients with delayed ischemic symptoms demonstrated relatively better outcomes than the seven patients who developed ischemic symptoms immediately postoperatively. CONCLUSION: Clinicians need to be more careful not to compromise distal blood flow when clipping UIAs at the MCA and AchA origin. Various intraoperative monitoring techniques can help reduce the incidence of compromised distal blood flow after clipping.