Pathological Findings of Donor Vessels in Bypass Surgery

(1) Background Cerebral revascularization is necessary to treat intracranial arterial stenosis caused by moyamoya disease, atherosclerosis, or large complex aneurysms. Although various donor vascular harvesting methods have been reported safe, there are no reports on the histological evaluation of donor vessels for each disease, despite the variety of diseases wherein vascular anastomosis is required. (2) Methods Pathological findings of the superficial temporal artery (STA), radial artery (RA), occipital artery (OA), and saphenous vein (SV) harvested at the institution were analyzed. Patients classified according to aneurysm, atherosclerosis, and moyamoya disease were assessed for pathological abnormalities, medical history, age, sex, smoking, and postoperative anastomosis patency. (3) Results There were 38 cases of atherosclerosis, 15 cases of moyamoya disease, and 30 cases of aneurysm in 98 donor vessels (mean age 57.2) taken after 2006. Of the 84 STA, 11 RA, 2 OA, and 1 SV arteries that were harvested, 71.4% had atherosclerosis, 11.2% had dissection, and 10.2% had inflammation. There was no significant difference in the proportion of pathological findings according to the disease. A history of hypertension is associated with atherosclerosis in donor vessels. (4) Conclusions This is the first study to histologically evaluate the pathological findings of donor vessels according to disease. The proportion of dissection findings indicative of vascular damage due to surgical manipulation was not statistically different between the different conditions.

Mortality risk factors and fulminant sub-phenotype in anaerobic bacteremia: a 10-year retrospective, multicenter, observational cohort study

PURPOSE

During the last decade, the incidence of anaerobic bacteremia (AB) has been increasing. Patients with AB may develop complex underlying diseases, which can occasionally be accompanied by fatal or fulminant outcomes. However, the risk factors for AB-related mortality remain unclear. Herein, we sought to elucidate the risk factors for AB-related mortality.

METHODS

In this multicenter, retrospective, observational study, we enrolled patients with culture-proven AB from six tertiary hospitals in Japan, between January 2012 and December 2021. Data on patient and infection characteristics, laboratory findings, treatment, and outcome were collected, and their associations with mortality were analyzed.

RESULTS

A total of 520 participants were included. The 30-day mortality in the study cohort was 14.0% (73 patients), and malignant tumors were frequently observed comorbidities in 48% of the entire cohort. Multivariable logistic regression analysis showed a Charlson comorbidity score of > 6, serum creatinine level of > 1.17 mg/dL, and hypotension to be independent risk factors for 30-day mortality in AB (odds ratios [ORs] 2.12, 2.25, and 5.12, respectively; p < 0.05), whereas drainage significantly reduced this risk (OR, 0.28; p < 0.0001). Twelve patients (2.3% of the whole cohort and 16.4% of the deceased patients) presented with extremely rapid progression leading to fatal outcome, consistent with "fulminant AB."

CONCLUSIONS

This study identified acute circulatory dysfunction and performance of drainage as independent predictive factors for 30-day AB-related mortality and revealed the existence of a fulminant AB sub-phenotype. Our findings could serve as a practical guide to predict the clinical outcomes of AB.

Identification and decompression of superior cluneal nerve implicated in low back pain

INTRODUCTION

Low back pain (LBP) can be attributable to entrapment of the superior cluneal nerve (SCN) around the iliac crest. Surgical decompression is a useful treatment; however, finding all entrapped SCNs involved in patients with LBP can be difficult. We performed a retrospective study to help identify entrapped SCNs in the narrow surgical field.

METHODS

We enrolled 20 LBP patient (22 sides) with SCN entrapment. They were 9 males and 11 females; their mean age was 72.5 years. We developed a 3-step procedure for successful SCN decompression surgery. In step 1, the thoracolumbar fascia is exposed and the SCN penetrating the fascia is released. In step 2, the fascia is opened and the SCN is released. In step 3, the fascia above the iliac crest is opened and the SCN is released.

RESULTS

We successfully released 66 nerves; the average was 3.0 ± 0.8 (1-4) per patient. Step 1 detected 18 nerves (27.3%), step 2 identified 35 (53.0%), and in step 3, 13 (19.7%) were recognized. By tracing the thin nerves branching off the SCN, we found 7 nerves (10.6%). We performed 22 operations; step 1 identified 16 SCNs (72.7%), step 2 identified 21 (95.5%), and step 3 found 12 nerves (54.5%).

CONCLUSIONS

The SCN is most readily identified upon opening of the thoracolumbar fascia. To identify as many SCN branches as possible, our 3-step method may be useful.

A clinicopathological study of low back pain due to middle cluneal nerve entrapment: case series

PURPOSE

The middle cluneal nerve (MCN) is a pure sensory nerve around the middle buttock. Its entrapment between the iliac crest and the long posterior sacroiliac ligament elicits low back pain (LBP) that can be treated by MCN neurolysis or neurectomy. Because few studies examined the pathology of MCN entrapment (MCN-E) we subjected 7 neurectomized specimens from 6 LBP patients to pathologic study.

METHODS

We present 6 consecutive patients (7 sides) with intractable LBP who underwent successful MCN neurectomy. Their symptom duration ranged from 6 to 96 months (average 47.3 months); the follow-up period ranged from 6 to 17 months (average 11.7 months). The surgical outcomes were evaluated using the numerical rating scale (NRS) for LBP and the Roland-Morris Disability Questionnaire (RDQ) score. The resected MCNs underwent neuropathological analysis.

RESULTS

Postoperatively, all 6 patients reported immediate LBP amelioration; their NRS and RDQ scores were improved significantly. Pathological study of the 7 resected nerves showed that the myelinated fiber density was decreased in 6 nerves; we observed marked enlargement (n = 5), perineurial thickening and disruption (n = 6), intrafascicular fibrous changes (n = 5), myelinated fibers separated by fibrous cells under the perineurium (n = 4), and Renaut bodies (n = 3). The 7th nerve appeared normal with respect to the density and size of the myelinated fibers, however, the perineurium was slightly thickened.

CONCLUSION

We present pathological evidence at the MCN compression site of 7 nerves from 6 patients whose LBP was alleviated by MCN neurectomy, indicating that MCN entrapment can elicit LBP.

Experience Using Gentian Violet-Free Dyes for Tissue Visualization

BACKGROUND

 Gentian violet ink is used as a skin marker in various surgical procedures, including neurosurgery. The dye is also used to visualize the edges of blood vessels during bypass surgery. However, gentian violet ink carries the risks of carcinogenicity and venous injury, which causes microvascular thrombosis. In this study, we compare the gentian violet-free dye C.I. Basic Violet 4 (BV4) and gentian violet. The usefulness, in terms of color, and formation of microvascular thrombosis in anastomosis were compared.

METHODS

 We used the gentian violet-free dye in 20 cases involving 3 vascular anastomoses. The bone cutting lines on the bone surface, superior temporal artery, and middle cerebral artery were drawn using BV4 and gentian violet ink.

RESULTS

 The colors of BV4 and gentian violet ink were similar. No thrombus formation was observed at the vascular anastomosis when using BV4.

CONCLUSION

 BV4 can be used similarly to gentian violet ink. No adverse effects such as thrombus formation in microvascular anastomosis were experienced when BV4 was used.

RNF213-Related Vasculopathy: Various Systemic Vascular Diseases Involving RNF213 Gene Mutations: Review

Moyamoya disease (MMD) is a cerebrovascular disorder that is predominantly observed in women of East Asian descent, and is characterized by progressive stenosis of the internal carotid artery, beginning in early childhood, and a distinctive network of collateral vessels known as "moyamoya vessels" in the basal ganglia. Additionally, a prevalent genetic variant found in most MMD cases is the p.R4810K polymorphism of RNF213 on chromosome 17q25.3. Recent studies have revealed that RNF213 mutations are associated not only with MMD, but also with other systemic vascular disorders, including intracranial atherosclerosis and systemic vascular abnormalities such as pulmonary artery stenosis and coronary artery diseases. Therefore, the concept of "RNF213-related vasculopathy" has been proposed. This review focuses on polymorphisms in the RNF213 gene and describes a wide range of clinical and genetic phenotypes associated with RNF213-related vasculopathy. The RNF213 gene has been suggested to play an important role in the pathogenesis of vascular diseases and developing new therapies. Therefore, further research and knowledge sharing through collaboration between clinicians and researchers are required.

Lung adenocarcinoma metastasis within a pituitary neuroendocrine tumor: a case report with review of literature

Collision tumors involving the metastasis of malignant neoplasms to pituitary neuroendocrine tumors (PitNETs) are extremely rare. We herein report a case involving a patient with lung adenocarcinoma metastasis within a PitNET who exhibited relatively rapid progression of neurological symptoms. A 75-year-old man who underwent tumor resection 36 and 18 years prior to presentation for bladder and colon cancer, respectively, without recurrence presented with bitemporal hemianopsia, ptosis, and diplopia of the right eye. Subsequent magnetic resonance imaging (MRI) revealed a tumor 3.2 cm in diameter that extended from the anterior pituitary gland to the suprasellar region. Gadolinium-enhanced MRI of the tumor showed heterogeneous contrast enhancement. Considering the relatively rapid progression of neurological symptoms, semi-emergency endoscopic endonasal transsphenoidal surgery was performed. Histopathological examination revealed a group of thyroid transcription factor-1- and napsin A-positive papillary proliferating cells intermingled with α-subunit- and steroidogenic factor-1-positive PitNET cells. Thus, the patient was diagnosed with lung adenocarcinoma metastasis within a gonadotroph PitNET. Genetic testing revealed the presence of an EGFR (Ex-19del) mutation, after which chemotherapy was initiated. Additional stereotactic radiotherapy was performed for the residual tumor in the sella turcica. With continued chemotherapy, good control of both the primary and metastatic tumors was noted after 24 months after surgery. Cases of malignant neoplasm metastasis within a PitNET are difficult to diagnose. In the case of a sella turcica tumor with relatively rapid progression of neurological symptoms, early surgical intervention is recommended given the possibility of a highly proliferative tumor and the need to obtain pathologic specimens.

Endoscopic spinal cord untethering using a 1 cm skin incision technique in pediatrics: a technical case report

BACKGROUND

Spinal cord untethering by sectioning the filum terminale is commonly performed in tethered cord syndrome patients with minor abnormalities such as filar lipoma, thickened filum terminale, and low conus medullaris. Our endoscopic surgical technique, using the interlaminar approach, allows for sectioning the filum terminale through a very small skin incision. To our knowledge, this procedure has not been previously reported. This is the first case report involving a 1 cm skin incision.

CASE PRESENTATION

A 9-month-old male patient was referred to our neurosurgical department due to a coccygeal dimple. MRI revealed a thickened fatty filum. After considering the treatment options for this patient, the parents agreed to spinal cord untethering. A midline 1 cm skin incision was made at the L4/5 vertebral level. Untethering by sectioning the filum terminale was performed by full endoscopic surgery using the interlaminar approach. The procedure was uneventful and there were no postoperative complications.

CONCLUSIONS

In terms of visibility and minimizing invasiveness, our surgical technique of using the interlaminar approach with endoscopy allows for untethering by sectioning the filum terminale through a very small skin incision.

A Case of Ruptured Carotid Traumatic Blood Blister-like Aneurysm

Ruptured cerebral aneurysms that occur in the anterior wall of the internal carotid artery (ICA) are known as blood blister-like aneurysms (BBAs); they have been reported to account for 0.3% to 1% of all ruptured ICA aneurysms. In this report, we describe the treatment of an unusual traumatic BBA (tBBA) with high-flow bypass using a radial artery graft, which resulted in a favorable outcome. A 59-year-old female suffered from an acute epidural hematoma, traumatic subarachnoid hemorrhage, and traumatic carotid-cavernous sinus fistula (tCCF) after being involved in a motor vehicle accident. Her angiography results showed tCCF and a tBBA on the anterior wall of the right ICA. On the fourth day after injury, we found rebleeding from the tBBA and performed an emergency high-flow bypass using a radial artery graft with lesion trapping as a curative procedure for the tCCF and tBBA. Postoperatively, right abducens nerve palsy appeared, but no other neurological symptoms were noted; the patient was thereafter transferred to a rehabilitation hospital 49 days after injury. Traumatic ICA aneurysms commonly occur close to the anterior clinoid process, form within 1 to 2 weeks of injury, and often rupture around 2 weeks after trauma. This case was considered rare as the ICA was likely injured and bleeding at the time of injury, resulting in a form of tBBA; this allowed early detection and appropriate treatment that resulted in a good outcome.

Spontaneous middle cerebral artery dissection: a series of six cases and literature review

Middle cerebral artery (MCA) dissection is rare, and various clinical presentations, including hemorrhage, ischemia, or comorbidities, and the changes in imaging findings over time hinder treatment decisions. The European Stroke Organization guidelines exclude MCA dissection. Few cases have been reported with no review of the relevant literature. Therefore, we reviewed the relevant literature and our own experience with non-traumatic MCA dissection cases to determine appropriate treatment strategies. At our institution and affiliated institutions, we encountered six cases of MCA dissection-five with infarction and one with hemorrhage. Two patients underwent revascularization, and one underwent an aneurysmectomy. We reviewed English and Japanese articles in PubMed and Medical Journal Web and summarized the results based on the relationships among age, sex, location, the presence of an aneurysm, the presence of angiography, history, treatment, and mode of onset. The clinical course, changes in imaging, treatment strategies, and prognosis were discussed. Eighty cases were included in the review. Cerebral aneurysms were more common distal to the M2 area (p = 0.00) and were correlated with hemorrhage (p < 0.001). Most hemorrhagic cases with aneurysms were treated surgically, while ischemic cases were treated with antithrombotic agents, and both had a similar neurological prognosis. There were some cases of rebleeding after antithrombotic therapy, especially in older adults.Surgical treatment is recommended in cases of hemorrhage and confirmed aneurysms, particularly for lesions distal to the M2 area. Patients with aneurysm-associated ischemia should be followed up, and antithrombotic treatment should be considered with particular care in older adults.

Predictive values of immune indicators on respiratory failure in the early phase of COVID-19 due to Delta and precedent variants

Background

Immune response indicators in the early phase of COVID-19, including interferon and neutralizing responses against SARS-CoV-2, which predict hypoxemia remains unclear.

Methods

This prospective observational study recruited patients hospitalized with COVID-19 (before emergence of omicron variant). As the immune indicators, we assessed the serum levels of IFN-I/III, IL-6, CXCL10 and VEGF, using an ELISA at within 5 days after the onset of symptoms, and serum neutralizing responses using a pseudovirus assay. We also assessed SARS-CoV-2 viral load by qPCR using nasal-swab specimens and serum, to assess the association of indicators and viral distribution.

Results

The study enrolled 117 patients with COVID-19, of which 28 patients developed hypoxemia. None received vaccine before admission. Serum IFN-I levels (IFN-α and IFN-β), IL-6, CXCL10, LDH and CRP were significantly higher in patients who developed hypoxemia. A significant association with nasopharyngeal viral load was observed only for IFN-I. The serum levels of IFN-α, IL-6, CXCL10 were significantly associated with the presence of RNAemia. Multivariable analysis showed higher odds ratio of IFN-α, with cut-off value of 107 pg/ml, in regard to hypoxemia (Odds ratio [OR]=17.5; 95% confidence interval [CI], 4.7-85; p<0.001), compared to those of IL-6, >17.9 pg/ml (OR=10.5; 95% CI, 2.9-46; p<0.001).

Conclusions

This study demonstrated that serum IFN-α levels in the early phase of SARS-CoV-2 infection strongly predict hypoxemic respiratory failure in a manner different from that of the other indicators including IL-6 or humoral immune response, and instead sensitively reflect innate immune response against SARS-CoV-2 invasion.

Rapidly progressive cerebral atrophy following a posterior cranial fossa stroke: Assessment with semiautomatic CT volumetry

BACKGROUND

The effect of posterior cranial fossa stroke on changes in cerebral volume is not known. We assessed cerebral volume changes in patients with acute posterior fossa stroke using CT scans, and looked for risk factors for cerebral atrophy.

METHODS

Patients with cerebellar or brainstem hemorrhage/infarction admitted to the ICU, and who underwent at least two subsequent inpatient head CT scans during hospitalization were included (n = 60). The cerebral volume was estimated using an automatic segmentation method. Patients with cerebral volume reduction > 0% from the first to the last scan were defined as the "cerebral atrophy group (n = 47)," and those with ≤ 0% were defined as the "no cerebral atrophy group (n = 13)."

RESULTS

The cerebral atrophy group showed a significant decrease in cerebral volume (first CT scan: 0.974 ± 0.109 L vs. last CT scan: 0.927 ± 0.104 L, P < 0.001). The mean percentage change in cerebral volume between CT scans in the cerebral atrophy group was -4.7%, equivalent to a cerebral volume of 46.8 cm³, over a median of 17 days. The proportions of cases with a history of hypertension, diabetes mellitus, and median time on mechanical ventilation were significantly higher in the cerebral atrophy group than in the no cerebral atrophy group.

CONCLUSIONS

Many ICU patients with posterior cranial fossa stroke showed signs of cerebral atrophy. Those with rapidly progressive cerebral atrophy were more likely to have a history of hypertension or diabetes mellitus and required prolonged ventilation.

Hyperfibrinolysis and fibrinolysis shutdown in patients with traumatic brain injury

Traumatic brain injury (TBI) is associated with coagulation/fibrinolysis disorders. We retrospectively evaluated 61 TBI cases transported to hospital within 1 h post-injury. Levels of thrombin-antithrombin III complex (TAT), D-dimer, and plasminogen activator inhibitor-1 (PAI-1) were measured on arrival and 3 h, 6 h, 12 h, 1 day, 3 days and 7 days after injury. Multivariate logistic regression analysis was performed to identify prognostic factors for coagulation and fibrinolysis. Plasma TAT levels peaked at admission and decreased until 1 day after injury. Plasma D-dimer levels increased, peaking up to 3 h after injury, and decreasing up to 3 days after injury. Plasma PAI-1 levels increased up to 3 h after injury, the upward trend continuing until 6 h after injury, followed by a decrease until 3 days after injury. TAT, D-dimer, and PAI-1 were elevated in the acute phase of TBI in cases with poor outcome. Multivariate logistic regression analysis showed that D-dimer elevation from admission to 3 h after injury and PAI-1 elevation from 6 h to 1 day after injury were significant negative prognostic indicators. Post-TBI hypercoagulation, fibrinolysis, and fibrinolysis shutdown were activated consecutively. Hyperfibrinolysis immediately after injury and subsequent fibrinolysis shutdown were associated with poor outcome.

Deterioration of cardiogenic shock after acute myocardial infarction defined by the society for cardiovascular angiography and intervention cardiogenic shock classification scheme

Background

Cardiogenic shock (CS) in patients with AMI presents worse cardiovascular outcomes, which suggests the need for better risk stratification and management. The Society for Cardiovascular Angiography and Intervention (SCAI) has recently proposed CS classification scheme, which stratifies CS into 5 groups according to hypotension and hypoperfusion. While stage A and B exhibits CS without hypotension and/or hypoperfusion, their clinical condition could rapidly deteriorate into stage C-E. However, clinical characteristics and in-hospital outcomes of CS exhibiting its deterioration remains uncertain.

Purpose

To characterize AMI patients who deteriorated their CS status from stage A and B into stage C-E.

Methods

This single-center observational study included 326 consecutive AMI patients receiving primary PCI who presented CS stage A and B on arrival (2019.09.01–2021.09.30). Deterioration of CS (D-CS) was defined as the progression from stage A and B on arrival to stage C-E after primary PCI. Clinical characteristics and outcomes were compared in those with and without D-CS.

Results

D-CS was identified in 16.0% of entire subjects (=52/326). Of these, 94.2 and 5.8% of them exhibited stage C and E, respectively (Figure). Patients with D-CS more likely presented STEMI (84.6 vs. 67.9%, p=0.01) with a lower systolic BP (sBP) level (130±31 vs. 148±26mmHg, p&lt;0.001) and a reduced LVEF (43±13 vs. 51±9%, p&lt;0.001), whereas there was no significant difference in lactate level (1.5±0.4 vs. 1.2±0.3 mmol/L, p=0.22). Pre-TIMI flow grade 0–1 (69.2 vs. 47.8%, p=0.006), left main trunk stenosis (9.6 vs. 1.5%, p=0.007) and chronic total occlusion (21.2 vs. 8.4%, p=0.01) were more frequently observed in those with D-CS. Despite achieving a shorter onset-to-reperfusion time (199 vs. 276 minutes, p=0.002), D-CS was associated with in-hospital all-cause mortality after adjusting clinical characteristics (HR=33.6, 95% CI: 2.2–502.0, p=0.01). Furthermore, mechanical circulatory support (MCS) (30.8 vs. 0%, p&lt;0.001) was more frequently required in patients with D-CS (IABP: 28.8 vs. 0%, p&lt;0.001, ECMO: 11.5 vs. 0%, p&lt;0.001, Impella: 3.8 vs. 0%, p=0.02). Further analysis identified sBP (HR=0.98, 95% CI: 0.97–1.00, p=0.008), LVEF (HR=0.94, 95% CI: 0.90–0.97, p&lt;0.001) and pre-TIMI flow grade 0–1 (HR=0.41, 95% CI: 0.19–0.86, p=0.01) as independent contributors to D-CS. ROC analysis demonstrated sBP &lt;135 mmHg (AUC=0.65) and LVEF &lt;50% (AUC=0.69) as best cut-off values to predict D-CS. Of note, a risk of D-CS increased in association with the number of these three factors (p&lt;0.001), and 44.0% of those with all of these factors presented D-CS (Figure).

Conclusion

16.0% of AMI without any hypotension/hypoperfusion on arrival exhibited deterioration of CS status on SCAI classification. The combination of sBP, LVEF and pre-TIMI flow grade could help to identify AMI subjects with a risk of D-CS, who may benefit from early adoption of intensified management including MCS prior to PCI.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of Ethyl Violet as an Alternative Dye to Crystal Violet to Visualize the Vessel Wall during Vascular Anastomosis

Crystal violet (CV) ink has been used as a skin marker worldwide. It has been reported to be useful for vessel wall visualization of microvascular anastomoses. Contrastingly, it has been found to be carcinogenic and inhibit migration and proliferation of venous cells. In some countries, its use in the medical field has been restricted. Therefore, it is necessary to consider alternatives to CV. In this present study, we compared the time required for the anastomosis of a 0.8-1 mm diameter vessel in the chicken wrist artery using CV and a CV-free dye (ethyl violet; EV). The surgeon, microscope, and anastomosis microsurgical tools were standardized for comparison. CV and EV were changed for each anastomosis. The same surgeon performed 30 anastomoses using each dye. No visually obvious differences were noted in the vascular transections with CV and EV. As per the results, no statistically significant difference was observed in the time required for anastomosis using CV and EV. EV conforming to California Proposition 65 may be an effective alternative to CV for vascular visualization of microvascular anastomoses. However, further studies on the effectiveness of the EV in clinical cases are needed.

Injury to the Extrasellar Portion of the Internal Carotid Artery during Endoscopic Transsphenoidal Surgery: A Case Report

Background

Injury to the internal carotid artery (ICA) during endoscopic transsphenoidal surgery (ETSS) is a serious complication with a risk of mortality. ICA injury during ETSS usually occurs during intrasellar manipulations and rarely occurs in the extrasellar portion. Several hemostatic procedures have been proposed for ICA injury in the intrasellar portion, whereas hemostatic methods for ICA injury in the extrasellar portion, where the ICA is surrounded by bone structures, are less well known.

Case Presentation

A 65-year-old man with an incidental pituitary tumor underwent ETSS. The petrous portion of the left ICA was injured during resection of the sphenoid septum connected with left carotid prominence using a cutting forceps. Bleeding was too heavy for simple hemostatic techniques. Hemostasis using a crushed muscle patch was tried unsuccessfully during controlling of the bleeding. Eventually, the injured site of the ICA was covered with cotton patties followed by closing with a vascularized pedicled nasoseptal flap. Cerebral angiography immediately after surgery showed no extravasation from the injured site of the left ICA petrous portion. However, a carotid-cavernous sinus fistula originating from the injured ICA site was detected 7 days after surgery, so the vascular reconstructive surgery combined with left ICA occlusion was performed. The overall postoperative course was uneventful.

Conclusion

We believe that emergency application of the cottonoids may be effective for hemostasis against ICA injury in the extrasellar portion during ETSS, but further vascular reconstruction combined with ICA occlusion on the injured side and removal of the cottonoids would be required.

Preliminary Clinical Surgical Experience with Temporary Simultaneous Use of an Endoscope during Exoscopic Neurosurgery: An Observational Study

The use of an endoscope in exoscopic transcranial neurosurgery for skull-base lesions has not yet been investigated. Thus, this study aimed to investigate the advantages, disadvantages, and safety of “simultaneous temporary use of an endoscope during exoscopic surgery” (exo-endoscopic surgery (EES)). Consecutive exo-endoscopic surgeries performed by experienced neurosurgeons and assistants were analyzed. Surgical complications and time were compared with previous consecutive microsurgeries performed by the same surgeon. A questionnaire survey was conducted on 16 neurosurgeons with experience in both “temporary simultaneous use of endoscope during microscopic surgery” (micro-endoscopic surgery (MES)) and EES. EES was performed in 18 of 76 exoscopic surgeries, including tumor removal (n = 10), aneurysm clipping (n = 5), and others (n = 3). There were no significant differences in operative time, anesthesia time, or complications from microsurgery by the same operator. According to the questionnaire survey results, compared with MES, EES had a wider field of view due to its lack of an eyepiece, was easier when loading and unloading instruments into and out of the surgical field, and was more suitable for the simultaneous observation of two fields of view. Overall, 79.2% of surgeons indicated that EES may be better suited than MES to simultaneously observe two fields of view.

Factors Influencing Long-Term Blood Flow in Extracranial-to-Intracranial Bypass for Symptomatic Internal Carotid Artery Occlusive Disease: A Quantitative Study

BACKGROUND

Maintaining the patency of extracranial-to-intracranial (EC-IC) bypass is critical for long-term stroke prevention. However, reports on the factors influencing long-term bypass patency and quantitative assessments of bypass patency are limited.

OBJECTIVE

To quantitatively evaluate blood flow in EC-IC bypass using four-dimensional (4D) flow magnetic resonance imaging (MRI) and investigate factors influencing the long-term patency of EC-IC bypass.

METHODS

Thirty-six adult Japanese patients who underwent EC-IC bypass for symptomatic internal carotid or middle cerebral artery occlusive disease were included. We examined the relationships between decreased superficial temporal artery (STA) blood flow volume and perioperative complications, long-term ischemic complications, patient background, and postoperative antithrombotic medications in patients for whom STA flow could be quantitatively assessed for at least 5 months using 4D flow MRI.

RESULTS

The mean follow-up time was 54.7 ± 6.1 months. One patient presented with a stroke during the acute postoperative period that affected postoperative outcomes. No recurrent strokes were recorded during long-term follow-up. Two patients died of malignant disease. Seven cases of reduced flow occurred in the STA, which were correlated with single bypass (P = .0294) and nonuse of cilostazol (P = .0294). STA occlusion was observed in 1 patient during the follow-up period. Hypertension, age, smoking, dyslipidemia, and diabetes mellitus were not correlated with reduced blood flow in the STA.

CONCLUSION

Double anastomoses and cilostazol resulted in long-term STA blood flow preservation. No recurrence of cerebral infarction was noted in either STA hypoperfusion or occlusion cases.

Acoustic Neurinoma with Synchronous Ipsilateral Cerebellopontine Angle Lipoma: A Case Report and Review of the Literature

Lipomas of the cerebellopontine angle (CPA) and internal auditory canal (IAC) are relatively rare tumors. Acoustic neurinoma is the most common tumor in this location, which often causes hearing loss, vertigo, and tinnitus. Occasionally, this tumor compresses the brainstem, prompting surgical resection. Lipomas in this area may cause symptoms similar to neurinoma. However, they are not considered for surgical treatment because their removal may result in several additional deficits. Conservative therapy and repeated magnetic resonance imaging examinations for CPA/IAC lipomas are standard measures for preserving cranial nerve function. Herein, we report a case of acoustic neurinoma and CPA lipoma occurring in close proximity to each other ipsilaterally. The main symptom was hearing loss without facial nerve paralysis. Therefore, facial nerve injury had to be avoided. Considering the anatomical relationships among the tumors, cranial nerves, and CPA/IAC lipoma, we performed total surgical removal of the acoustic neurinoma. We intentionally left the lipoma untreated, which enabled facial nerve preservation. This report may be a useful reference for the differential diagnosis of similar cases in the future.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC₅₀ value of PLC/PRF/5 cells from 13.0±0.8 μM in normoxia to 21.3±1.1 μM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

Rapidly progressive brain atrophy in septic ICU patients: a retrospective descriptive study using semiautomatic CT volumetry

Background

Sepsis is often associated with multiple organ failure; however, changes in brain volume with sepsis are not well understood. We assessed brain atrophy in the acute phase of sepsis using brain computed tomography (CT) scans, and their findings’ relationship to risk factors and outcomes.

Methods

Patients with sepsis admitted to an intensive care unit (ICU) and who underwent at least two head CT scans during hospitalization were included (n = 48). The first brain CT scan was routinely performed on admission, and the second and further brain CT scans were obtained whenever prolonged disturbance of consciousness or abnormal neurological findings were observed. Brain volume was estimated using an automatic segmentation method and any changes in brain volume between the two scans were recorded. Patients with a brain volume change < 0% from the first CT scan to the second CT scan were defined as the “brain atrophy group (n = 42)”, and those with ≥ 0% were defined as the “no brain atrophy group (n = 6).” Use and duration of mechanical ventilation, length of ICU stay, length of hospital stay, and mortality were compared between the groups.

Results

Analysis of all 42 cases in the brain atrophy group showed a significant decrease in brain volume (first CT scan: 1.041 ± 0.123 L vs. second CT scan: 1.002 ± 0.121 L, t (41) = 9.436, p < 0.001). The mean percentage change in brain volume between CT scans in the brain atrophy group was –3.7% over a median of 31 days, which is equivalent to a brain volume of 38.5 cm³. The proportion of cases on mechanical ventilation (95.2% vs. 66.7%; p = 0.02) and median time on mechanical ventilation (28 [IQR 15–57] days vs. 15 [IQR 0–25] days, p = 0.04) were significantly higher in the brain atrophy group than in the no brain atrophy group.

Conclusions

Many ICU patients with severe sepsis who developed prolonged mental status changes and neurological sequelae showed signs of brain atrophy. Patients with rapidly progressive brain atrophy were more likely to have required mechanical ventilation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03828-7.

Cross-Comparison of 4-Dimensional Flow Magnetic Resonance Imaging and Intraoperative Middle Cerebral Artery Pressure Measurements Before and After Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery

BACKGROUND

The hemodynamic changes after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery are unclear.

OBJECTIVE

To clarify the hemodynamics by comparing flow parameters obtained by 4-dimensional (4D) flow magnetic resonance imaging (MRI) and intraoperative MCA pressure measurement.

METHODS

We recruited 23 patients who underwent STA-MCA bypass surgery for internal carotid artery (ICA) or MCA stenosis. We monitored intraoperative MCA, STA, and radial artery (RA) pressure. All patients underwent 4D flow MRI preoperatively and 3 wk after surgery to quantify the blood flow volume (BFV) of the ipsilateral ICA (BFViICA), contralateral ICA (BFVcICA), basilar artery (BFVBA), ipsilateral STA (BFViSTA), and contralateral STA (BFVcSTA). The sum of intracranial BFV was defined as BFVtotal. We compared BFV parameters and intraoperative pressure.

RESULTS

BFViSTA significantly increased after surgery (P < .001). BFViICA and BFVBA significantly decreased after surgery (BFViICAP = .005; BFVBAP = .02). No significant difference was observed between BFVcICA before and after surgery. As a result, BFVtotal postoperatively increased by 6.8%; however, no significant difference was observed. Flow direction at M1 changed from antegrade to unclear after surgery in 5 patients. Intraoperative MCA pressure and MCA/RA pressure ratio significantly increased after surgery (P < .001). We found a stronger positive correlation between MCA pressure increase ratio and BFVtotal increase ratio in patients with lower pre-MCA pressure (r = 0.907, P < .001).

CONCLUSION

The visual and quantitative assessment of 4D flow MRI revealed that intracranial blood flow changes complementarily after STA-MCA bypass surgery. 4D flow MRI may detect the improvement of cerebral perfusion pressure.

Investigation of Objectivity in Scoring and Evaluating Microvascular Anastomosis Simulation Training

The increase in minimally invasive surgery has led to a decrease in surgical experience. To date, there is only limited research examining whether skills are evaluated objectively and equally in simulation training, especially in microsurgery. The purpose of this study was to analyze the objectivity and equality of simulation evaluation results conducted in a contest format. A nationwide recruitment process was conducted to select study participants. Participants were recruited from a pool of qualified physicians with less than 10 years of experience. In this study, the simulation procedure consisted of incising a 1 mm thick blood vessel and suturing it with a 10-0 thread using a microscope. Initially, we planned to have the neurosurgical supervisors score the simulation procedure by direct observation. However, due to COVID-19, some study participants were unable to attend. Thus requiring some simulation procedures to be scored by video review. A total of 14 trainees participated in the study. The Cronbach’s alpha coefficient among the scorers was 0.99, indicating a strong correlation. There was no statistically significant difference between the scores from the video review and direct observation judgments. There was a statistically significant difference (p <0.001) between the scores for some criteria. For the eight criteria, individual scorers assigned scores in a consistent pattern. However, this pattern differed between scorers indicating that some scorers were more lenient than others. The results indicate that both video review and direct observation methods are highly objective techniques evaluate simulation procedures.

Assessing the development status of intraoperative fluorescence imaging for perfusion assessments, using the IDEAL framework

Objectives

Intraoperative fluorescence imaging is currently used in a variety of surgical fields for four main purposes: assessing tissue perfusion; identifying/localizing cancer; mapping lymphatic systems; and visualizing anatomy. To establish evidence-based guidance for research and practice, understanding the state of research on fluorescence imaging in different surgical fields is needed. We evaluated the evidence on fluorescence imaging for perfusion assessments using the Idea, Development, Exploration, Assessment, Long Term Study (IDEAL) framework, which was designed for describing the stages of innovation in surgery and other interventional procedures.

Design

Narrative literature review with analysis of IDEAL stage of each field of study.

Setting

All publications on intraoperative fluorescence imaging for perfusion assessments reported in PubMed through 2019 were identified for six surgical procedures: coronary artery bypass grafting (CABG), upper gastrointestinal (GI) surgery, colorectal surgery, solid organ transplantation, reconstructive surgery, and cerebral aneurysm surgery.

Main outcome measures

The IDEAL stage of research evidence was determined for each specialty field using a previously described approach.

Results

196 articles (15 003 cases) were selected for analysis. Current status of research evidence was determined to be IDEAL Stage 2a for upper GI and transplantation surgery, IDEAL 2b for CABG, colorectal and cerebral aneurysm surgery, and IDEAL Stage 3 for reconstructive surgery. Using the technique resulted in a high (up to 50%) rate of revisions among surgical procedures, but its efficacy improving postoperative outcomes has not yet been demonstrated by randomized controlled trials in any discipline. Only one possible adverse reaction to intravenous indocyanine green was reported.

Conclusions

Using fluorescence imaging intraoperatively to assess perfusion is feasible and appears useful for surgical decision making across a range of disciplines. Identifying the IDEAL stage of current research knowledge aids in planning further studies to establish the potential for patient benefit.

RNF213 c.14576G>A Is Associated with Intracranial Internal Carotid Artery Saccular Aneurysms

A mutation in RNF213 (c.14576G>A), a gene associated with moyamoya disease (>80%), plays a role in terminal internal carotid artery (ICA) stenosis (>15%) (ICS). Studies on RNF213 and cerebral aneurysms (AN), which did not focus on the site of origin or morphology, could not elucidate the relationship between the two. However, a report suggested a relationship between RNF213 and AN in French-Canadians. Here, we investigated the relationship between ICA saccular aneurysm (ICA-AN) and RNF213. We analyzed RNF213 expression in subjects with ICA-AN and atherosclerotic ICS. Cases with a family history of moyamoya disease were excluded. AN smaller than 4 mm were confirmed as AN only by surgical or angiographic findings. RNF213 was detected in 12.2% of patients with ICA-AN and 13.6% of patients with ICS; patients with ICA-AN and ICS had a similar risk of RNF213 mutation expression (odds ratio, 0.884; 95% confidence interval, 0.199-3.91; p = 0.871). The relationship between ICA-AN and RNF213 (c.14576G>A) was not correlated with the location of the ICA and bifurcation, presence of rupture, or multiplicity. When the etiology and location of AN were more restricted, the incidence of RNF213 mutations in ICA-AN was higher than that reported in previous studies. Our results suggest that strict maternal vessel selection and pathological selection of AN morphology may reveal an association between genetic mutations and ICA-AN development. The results of this study may form a basis for further research on systemic vascular diseases, in which the RNF213 (c.14576G>A) mutation has been implicated.

A case of suspected low-pressure hydrocephalus caused by spinal drainage following subarachnoid hemorrhage

BACKGROUND

Hydrocephalus induced by low cerebrospinal fluid (CSF) pressure is extremely rare and sporadically reported. Subarachnoid hemorrhage, head trauma, and spinal drainage were reported to be the causative factors for surgical treatments.

CASE DESCRIPTION

A 33-year-old male with subarachnoid hemorrhage caused by right vertebral artery aneurysm rupture developed a headache. A trapping surgery was performed, and a spinal drain was inserted from the lumbar L4/5 for subarachnoid hemorrhage washout. On postoperative day 3, increase in subdural fluid accumulation at the posterior fossa craniotomy site and narrowing of the cerebellar sulci appeared in addition to mild enlargement of the ventricles. The patient complained of a headache during head elevation. Low-pressure hydrocephalus (LPH) was suspected. The spinal drain was removed, the headache was relieved, and cerebral ventriculomegaly disappeared. The subsequent clinical course was good. The patient was discharged 3 weeks after the surgery.

DISCUSSION

LPH is a rare disease caused by various factors and is treated by correcting liquorrhea or overdrainage, if any. Otherwise, drainage at a negative CSF pressure is necessary. Its symptoms and image findings are similar to those of intracranial hypertension and normal-pressure hydrocephalus. This paper reports a suspected LPH case caused by spinal drainage following subarachnoid hemorrhage with literature review.

Role of RNF213 polymorphism in defining quasi-moyamoya disease and definitive moyamoya disease

OBJECTIVE

Quasi-moyamoya disease (QMMD) is moyamoya disease (MMD) associated with additional underlying diseases. Although the ring finger protein 213 (RNF213) c.14576G>A mutation is highly correlated with MMD in the Asian population, its relationship to QMMD is unclear. Therefore, in this study the authors sought to investigate the RNF213 c.14576G>A mutation in the genetic diagnosis and classification of QMMD.

METHODS

This case-control study was conducted among four core hospitals. A screening system for the RNF213 c.14576G>A mutation based on high-resolution melting curve analysis was designed. The prevalence of RNF213 c.14576G>A was investigated in 76 patients with MMD and 10 patients with QMMD.

RESULTS

There were no significant differences in age, sex, family history, and mode of onset between the two groups. Underlying diseases presenting in patients with QMMD were hyperthyroidism (n = 6), neurofibromatosis type 1 (n = 2), Sjögren's syndrome (n = 1), and meningitis (n =1). The RNF213 c.14576G>A mutation was found in 64 patients (84.2%) with MMD and 8 patients (80%) with QMMD; no significant difference in mutation frequency was observed between cohorts.

CONCLUSIONS

There are two forms of QMMD, one in which the vascular abnormality is associated with an underlying disease, and the other in which MMD is coincidentally complicated by an unrelated underlying disease. It has been suggested that the presence or absence of the RNF213 c.14576G>A mutation may be useful in distinguishing between these disease types.

Lesion Trapping with High-Flow Bypass for Ruptured Internal Carotid Artery Blood Blister-Like Aneurysm Has Little Impact on the Anterior Choroidal Artery Flow: Case Series and Literature Review

OBJECTIVE

To examine the relationship between trap location and cerebral infarction in the anterior choroidal artery (AChA) region and associated risks in ruptured internal carotid artery blood blister-like aneurysm (BLA) treatment with high-flow bypass and lesion trapping.

METHODS

We included 26 patients diagnosed with BLAs and treated with high-flow bypass and trapping. We examined clinical characteristics including age, aneurysm trap location, final prognosis, cerebral infarction on postoperative magnetic resonance imaging, and modified Rankin Scale score at discharge. We also searched the literature for similar studies.

RESULTS

The modified Rankin Scale score at discharge was 0-2 in 20 patients, 3-5 in 2 patients, and 6 in 2 patients. In 19/26 patients (73.1%), the trapped segment was between the posterior communicating (PcomA) and the ophthalmic arteries. In 2 patients (7.7%), the trapped segment included the PcomA and the AChA; in 4 patients (15.4%), the trapped segment was within the PcomA. In these patients, the PcomA was occluded, and blood from the high-flow bypass flowed out to the AChA alone. No patient showed cerebral infarction. Our systematic review identified 70 patients. Of all 96 patients, 12 had AChA cerebral infarction; however, the infarction affected the prognosis of only 2 patients.

CONCLUSIONS

When treating BLAs with high-flow bypass and lesion trapping, the frequency of AChA cerebral infarction is low even when the PcomA is occluded, leaving the AChA as the only outflow vessel during high-flow bypass. However, PcomA occlusion may be associated with risks when treating patients with advanced arteriosclerosis near C1-2.

Open surgical embolectomy for cardiogenic cerebral embolism: Technical note and its advantages

BACKGROUND AND IMPORTANCE

In cardiogenic cerebral embolism, early recanalization is the most important factor for good prognosis. However, endovascular thrombectomy often fails to achieve recanalization. We present an open surgical embolectomy technique and discuss its advantages.

CLINICAL PRESENTATION

A 79-year-old woman developed right hemiparesis and severe aphasia. Magnetic resonance imaging revealed an acute cerebral infarction caused by left middle cerebral artery (MCA) occlusion. We attempted endovascular thrombectomy but failed because it was impossible to guide the catheter to the occlusion site. Hence, we converted to open surgical embolectomy. Sylvian fissure was widely opened. After confirming the range of thrombosis using indocyanine green videoangiography (ICGVAG), the proximal and distal arteries were secured, and a temporary clip was placed on the distal M2 to prevent distal thrombosis migration. MCA was cut approximately 3 mm from the bifurcation, and thrombosis was removed using micro-forceps. The proximal clip was simultaneously inserted but was not clamped because the thrombus was extruded by proximal vascular flow. Immediately after removing the thrombus, intense bleeding occurred from the proximal flow. An assistant clamped the proximal artery using the prepared clip, and the incised area of MCA was sutured using 9-0 threads. We finally confirmed blood flow after recanalization using ICGVAG. The time from skin incision to recanalization was 27 min. After the procedure, the patient developed slight aphasia but had no hemiparesis and was later transferred to a rehabilitation hospital.

CONCLUSION

Open surgical embolectomy may be a secondary rescue treatment option in the case of endovascular thrombectomy failure.

The validity of the simple methods of estimating chronic subdural hematoma volume

OBJECTIVES

It was reported that the XYZ/2 technique (using length, width and height of hematoma) is a simple and reliable method of estimation of chronic subdural hematoma volume. Two subtypes of techniques enable to adequately estimate, it is unclear which is more accurate. Computer-assisted volumetric analysis is widely considered the gold standard for CSDH volumetric analysis. It is important to consider the stability of analyses between examiners, because individual, decision-making differences may be relevant to the analysis, as hematoma margin and length are hand-operated. In this study, we investigated potential measurement biases of three neurosurgeons and analyzed the validity of the XYZ/2 technique by comparing it to the gold standard method.

METHOD

We retrospectively analyzed CT scans that indicated the need for an operation in 50 patients with CSDH in our department. Three neurosurgeons measured and calculated CSDH volumes independent of one another. We investigated potential measurement biases of three neurosurgeons and analyzed the validity of the XYZ/2 technique by comparing it to the gold standard method. The XYZ/2 technique includes the "maximal method" that uses the maximum length and maximum width of a slice to determine volume, and the "central method" that uses only the central slice to measure length and width.

RESULTS

ICCs for the gold standard, central method, and maximal method were 0.945, 0.916, and 0.844, respectively, all of which indicated excellent reliability. For all examiners, the differences in calculation from gold standard and central method were not statistically significant (P>0.05). The estimations of CSDH volume calculated by the maximal method were significantly greater than the estimates calculated by the gold standard (P<0.05).

CONCLUSIONS

This study proves that the XYZ/2 technique is a simple and reliable method of estimating CSDH volume. The "central method" in particular yielded similar results to that of the gold standard method.

Case Report: A Case of Moyamoya Syndrome Associated With Multiple Endocrine Neoplasia Type 2A

To the best of our knowledge, we report a case of MEN2A complicated by moyamoya syndrome. A 52-year-old woman presented with vertigo. Magnetic resonance angiography (MRA) revealed bilateral supraclinoid stenosis of the internal carotid artery and abnormal moyamoya-like vessels around the basal ganglia. She had a heterozygous variant of RNF213, which is the susceptibility gene for moyamoya disease. She had also previously received diagnoses of medullary thyroid carcinoma (MTC) at age 23 and left-sided pheochromocytoma (PHEO) at age 41. Genetic testing revealed heterozygosity for a mutation at codon 634 in exon 11 (TGC-TTC mutation; p.Cys634Phe) of the Ret gene. Intracranial vascular stenosis may have been caused by a genetic mutation of RNF213 and hypersecretion of catecholamines by MEN2A. Physicians should recognize that MEN2A can be present with moyamoya syndrome.

Preliminary Clinical Microneurosurgical Experience With the 4K3-Dimensional Microvideoscope (ORBEYE) System for Microneurological Surgery: Observation Study

BACKGROUND

The exoscope has been reported as a novel neurosurgical instrumentation in clinical practice.

OBJECTIVE

To investigate the possibility that ORBEYE (OE), a novel instrument that excludes eyepiece lenses and allows for microsurgery by observation of the 4K3D monitor, could replace microscopes.

METHODS

We report 22 clinical cases by 5 experienced neurosurgeons and the comparative results of training 10 residents. An observation study with questionnaire survey was conducted on usability. Twelve items including image quality, eyestrain, and function of the arm were evaluated.

RESULTS

The following 22 clinical procedures were conducted: surgery for intracranial hemorrhage (n = 2) and brain tumor (n = 8), laminectomy (n = 3), aneurysm clipping (n = 3), vascular anastomosis (n = 2), carotid endarterectomy (n = 2), and nerve decompression (n = 1). No complications were observed. The fluorescent study, including indocyanine-green and 5-aminolevunic acid, allowed for clear depiction on the 4K monitor. The surgeon could operate in a comfortable posture. Similar to the microscope, it was possible to change the optical and viewing axes with the OE, but the OE was switched to the microscope or endoscope in hematoma removal and pituitary surgery. Residents judged that eyestrain was strong (P = .0096). Experienced neurosurgeons acting as assistants judged that the scope arm's range of movement was narrow (P = .0204). Sixty percent of residents judged that the OE was superior to the microscope.

CONCLUSION

Although based on limited experience, it was not possible to substitute the microscope with the OE in all operations; however, the OE surpasses the microscope in terms of ergonomic features.

Radial Artery Graft for Giant Common Carotid Artery Pseudoaneurysm After Carotid Artery Stenting

BACKGROUND

We present a patient who underwent left superior temporal artery (STA)-to-right middle cerebral artery (MCA) bypass using a radial artery (RA) graft with resection of a giant right cervical common carotid artery (CCA) pseudoaneurysm after carotid artery stenting (CAS) and discuss the treatment strategy and surgical procedure in detail.

CASE DESCRIPTION

An 86-year-old male presented with sudden onset of altered consciousness and complete left hemiparesis. Magnetic resonance angiography and catheter angiography of the brain revealed occlusion of the right cervical ICA. Endovascular thrombectomy and stenting of the cervical segment of the ICA were performed. Thirty-two days after CAS, the patient developed a high fever and rapid swelling of the neck. Catheter angiography showed a giant right CCA pseudoaneurysm that had a fistula just proximal to the carotid stent, and the aneurysm extended to the neck entirely. Because of the expanding neck infection, stent placement long lesion, and lack of distal collateral flow on angiography, we performed aneurysm and stent removal and left STA-to-right MCA bypass using an RA graft. The harvested RA graft was anastomosed side to end to both the M2 segment of the right MCA and the left STA. Bypass patency was confirmed before neck exposure. The pseudoaneurysm and proximal portion area of the stent were resected. The patient recovered well postoperatively, and follow-up catheter angiography showed patency of the bypass.

CONCLUSIONS

Left STA-RA-right MCA bypass with aneurysm resection is a good treatment option for giant CCA pseudoaneurysms that occur after CAS.

Second Free Flap Surgery for Skull Base Tumors: Case Report and Literature Review

Tumors of the skull base, such as meningiomas, tend to recur. With progress in free vascularized flap surgery, an increasing number of studies are investigating skull base reconstruction with free flaps after tumor removal. In this report, we discuss the results of second free flap surgery after skull base reconstructive surgery. We retrospectively analyzed data from patients treated at our center during the period from 2013 through 2017. All four patients identified had skull base anaplastic meningioma and had undergone radiotherapy. In all cases, the flap and donor blood vessel were sourced from sites that differed from those used in the previous surgeries. No complications developed, such as cerebrospinal fluid leakage, meningitis, wound infection, wound hemorrhage, or flap necrosis. Because the first flap was found to be unviable, it was difficult to preserve and was removed. Essential points in preventing complications are anchoring at the appropriate site, pinprick testing of the created flap, and use of multilayered countermeasures to prevent cerebrospinal fluid leakage.

Quantitative Comparison of the Intraoperative Utility of Indocyanine Green and Fluorescein Videoangiographies in Cerebrovascular Surgery

BACKGROUND

A quantitative analysis comparing indocyanine green videoangiography (ICG-VAG) and fluorescein videoangiography (FL-VAG) in cerebrovascular surgery has not been reported so far.

OBJECTIVE

To clear the differences of characteristics of ICG-VAG and FL-VAG by quantitative assessment.

METHODS

We prospectively analyzed results from 23 patients (3 males; mean age at surgery: 60.9 years, range: 14-75 years) at our hospital from August 2014 to July 2015. Eighteen patients had cerebral aneurysms for clipping, and 5 had intracranial arterial stenosis for superficial temporal artery (STA)-middle cerebral artery bypass. We imported data from the operative image data, converted by Audio Video Interleave to Aquacosmos as picture fluorescence intensity-analyzing software. Regions of interest were set at the parent artery, dome of aneurysms, and perforating artery in cases of clipping of aneurysms, and setting at 3 points in STA, in case of bypass. The transition of fluorescence intensity at each region of interest was calculated and plotted using Aquacosmos.

RESULTS

Thick-walled artery, such as parent artery ( P = .0017) and STA ( P = .0182), was more significantly visualized by ICG-VAG than FL-VAG, whereas the perforating artery, especially in deep surgical fields, such as anterior communicating artery, internal carotid artery, and basilar artery, was better visualized by FL-VAG than ICG-VAG ( P < .0001).

CONCLUSION

In this quantitative analysis of fluorescence study, ICG-VAG showed greater efficacy than FL-VAG in visualizing relatively thick arteries, such as parent artery and STA. However, FL-VAG has greater efficacy than ICG-VAG in visualizing perforating artery, especially in deep surgical fields with characteristic vessel walls.

Serum Glucose and Potassium Ratio as Risk Factors for Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Cerebral vasospasm is associated with poor prognosis in patients with aneurysmal subarachnoid hemorrhage (SAH), and biomarkers for predicting poor prognosis have not yet been established. We attempted to clarify the relationship between serum glucose/potassium ratio and cerebral vasospasm in patients with aneurysmal SAH.

METHODS

We studied 333 of 535 aneurysmal SAH patients treated between 2006 and 2016 (123 males, 210 females; mean age 59.7 years; range 24-93). We retrospectively analyzed the relationship between cerebral vasospasm grade and clinical risk factors, including serum glucose/potassium ratio.

RESULTS

Postoperative angiography revealed cerebral vasospasm in 112 patients (33.6%). Significant correlations existed between the ischemic complication due to cerebral vasospasm and glucose/potassium ratio (P < .0001), glucose (P = .016), and potassium (P = .0017). Serum glucose/potassium ratio was elevated in the cerebral vasospasm grade dependent manner (Spearman's r = 0.1207, P = .0279). According to the Glasgow Outcome Scale (GOS) score at discharge, 185 patients (55.5%) had a poor outcome (GOS scores 1-3). Serum glucose/potassium ratio was significantly correlated between poor outcome (GOS scores 1-3) and age (P < .0001), serum glucose/potassium ratio (P < .0001), glucose (P < .0001), potassium (P = .0004), white blood cell count (P = .0012), and cerebral infarction due to cerebral vasospasm (P < .0001). Multivariate logistic regression analyzes showed significant correlations between cerebral infarction due to cerebral vasospasm and serum glucose/potassium ratio (P = .018), glucose (P = .027), and potassium (P = .052).

CONCLUSIONS

Serum glucose/potassium ratio in cases of aneurysmal SAH was significantly associated with cerebral infarction due to cerebral vasospasm and GOS at discharge. Therefore, this factor was useful to predict prognosis in patients with cerebral vasospasm and aneurysmal SAH.

Efficacy of Thyrotropin-Releasing Hormone Analog for Protracted Disturbance of Consciousness due to Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

The efficacy of thyrotropin-releasing hormone tartrate (TRH-T) for treating prolonged disturbance of consciousness due to aneurysmal subarachnoid hemorrhage (SAH) remains unclear. The purpose of the present study was to determine whether TRH-T was really effective, and what was the recovery factor when it was valid. This was a retrospective study of a single facility.

METHODS

We treated 208 patients with aneurysmal SAH at our hospital between 2011 and 2017. Among them, we investigated 97 cases in which TRH-T was administered to prolonged disturbance of consciousness. Thirty one patients with Hasegawa dementia rating scale-revised (HDS-R) score less than 20 were included. Patients' HDS-R scores were evaluated 7 days after clipping the aneurysm and 2 days after completing a course of TRH-T treatment. HDS-R score increases of greater than or over equal to 8 and less than 8 were defined as good and poor outcomes, respectively. Outcomes were compared to 11 patients who did not receive TRH-T treatment.

RESULTS

Average initial and post-treatment HDS-R scores were 9 ± 6.6 and 19 ± 9.5, respectively. The good outcome group included 19 patients. Statistically significant differences in HDS-R score changes were observed between the group with initial HDS-R scores of 0-4 and the other groups. Poor outcomes were significantly correlated with age of greater than 60 years and initial HDS-R scores less than oroverequal to 4 points. The improvement in HDS-R score was significantly greater in the TRH-T administration group than the control group.

CONCLUSIONS

TRH-T was effective for treating prolonged disturbance of consciousness due to aneurysmal SAH, especially in young patients with HDS-R scores between 5 and 20.

Optical effects on the surrounding structure during quantitative analysis using indocyanine green videoangiography: A phantom vessel study

Various reports have been published regarding quantitative evaluations of intraoperative fluorescent intensity studies using indocyanine green (ICG) with videoangiography (VAG). The effects of scattering and point-spread functions (PSF) on quantitative ICG-VAG evaluations have not been investigated. Clinically, when ICG is administered through the peripheral vein, it reaches the tissue intra-arterially. To achieve more reliable intraoperative quantitative intensity evaluations, we examined the impact of high-intensity structures on close areas. The study was conducted using a phantom model and surgical fluorescent microscope. A region of interest (ROI) was created for the vessel model and another ROI was created within 3 cm of that. With an ROI of 6.8 mm in the vessel phantom model, 10% intensity was confirmed, even though there was no fluorescent structure. Intensity decreased gradually as the ROI moved further from the vessel model. Our study results suggest that the presence of a high-intensity structure and the size of the ROI may affect quantitative intensity evaluations using ICG-VAG. Results of linear regression analysis indicate that the relationship of intensity (Y) and distance (X) is as follows: Y(real/A) = 29 Exp(-0.062X) + 164.3 Exp(-1.81X). The optical effect should be considered when performing an intraoperative intensity study with a surgical microscope.

Serum glucose/potassium ratio as a clinical risk factor for aneurysmal subarachnoid hemorrhage

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (SAH) can result in poor outcomes, and biomarkers for predicting poor prognosis have not yet been established. The aim of this study was to clarify the significance of the serum glucose/potassium ratio for predicting the prognosis of aneurysmal SAH.

METHODS

The authors retrospectively reviewed the records of 565 patients with aneurysmal SAH between 2006 and 2016. The patient group comprised 208 men and 357 women (mean age 61.5 years, range 10-95 years). A statistical analysis was conducted of the clinical and laboratory risk factors of poor outcome, including the serum glucose/potassium ratio.

RESULTS

On estimation of the initial assessment using Hunt and Kosnik (H-K) grading, 233 patients (41.2%) were classified as the severe SAH group (H-K Grade IV or V). There were significant correlations between the severe SAH group and serum glucose/potassium ratio (p < 0.0001). Serum glucose/potassium ratio was elevated in an H-K grade-dependent manner (Spearman's r = 0.5374, p < 0.0001). With the estimation of the Glasgow Outcome Scale (GOS) score at discharge, 355 patients (62.8%) were classified as poor outcome (GOS score 1-3). The serum glucose/potassium ratio was elevated in a GOS score at discharge-dependent manner (Spearman's r = 0.4006, p < 0.0001), and was significantly elevated in the poor outcome group compared with the good outcome group (GOS score 4 or 5; p = 0.0245). There were significant correlations between poor outcome and serum glucose/potassium ratio (p < 0.0001), age (p < 0.0001), brain natriuretic peptide levels (p = 0.011), cerebral infarction due to vasospasm (p < 0.0001), and H-K grade (p < 0.0001). Multivariate logistic regression analyses showed significant correlations between poor outcome and serum glucose/potassium ratio (p = 0.009).

CONCLUSIONS

In this study, the serum glucose/potassium ratio of patients with aneurysmal SAH at admission was significantly correlated with H-K grade and GOS score at discharge. Therefore, this ratio was useful for predicting prognosis of aneurysmal SAH, especially in severe cases.

Radiological findings of transorbital penetrating intracranial injury in a child

In penetrating injuries, woods are known to be difficult to detect with radiological imaging studies, because the wood density are known to be extremely close to the value of air on CT. Adjustment of CT window and reconstruction of a 3D image from CT images allowed us to more accurately distinguish wood from air and to find the fragment of the wooden chopstick. It is particularly useful in transorbital penetrating injury.

Cerebral Aneurysm Associated with an Arachnoid Cyst: 3 Case Reports and a Systematic Review of the Literature

BACKGROUND

Arachnoid cysts and intracranial aneurysms are not rare, but it is unusual for an aneurysm to be associated with an arachnoid cyst. The objective of this study was to reveal the association between arachnoid cysts and intracranial aneurysms.

METHODS

Methods included to report 3 cases with these 2 pathologies and to perform a systematic review of the English and Japanese literature using PubMed, Scopus, and Ichushi Web.

RESULTS

The first case was of a 46-year-old man with a subarachnoid hemorrhage on the basal cistern and bilateral arachnoid cysts in the middle fossa, the second was that of a 29-year-old woman with a subarachnoid hemorrhage at the basal cistern and an arachnoid cyst in the left middle fossa, and the third was that of a 60-year-old man with a right putaminal hemorrhage and contralateral unruptured aneurysm and arachnoid cyst. A literature search for similar cases found 27 patients.

CONCLUSIONS

It was difficult to diagnose a ruptured aneurysm in some cases with an arachnoid cyst because computed tomography scan showed atypical findings, such as no hemorrhage, intracystic localized hemorrhage, or subdural hematoma. This review revealed that aneurysms and arachnoid cysts were significantly located ipsilaterally and that they occurred together in relatively young patients.

Bilateral suboccipital approach for a giant vertebral artery aneurysm

Giant thrombosed aneurysms of the vertebral artery (VA) are difficult to treat. Moreover, marked tortuosity of the parent VA complicates determination of the surgical approach. We report the case of a 71-year-old male patient who presented with gait disturbance. Magnetic resonance imaging revealed a giant thrombosed aneurysm of approximately 4cm in diameter located in the ventral region and to the right of the medulla oblongata. Computed tomography angiography showed that the right VA had extreme tortuosity, and that the VA union was in contact with the left 7th and 8th cranial nerves. Given that the aneurysm was thrombosed and causing a mass effect, we sought to trap it. In this case, because of the tortuous VA, intravascular team considered intravascular therapy to be too difficult. We made a question mark-shaped skin incision and used a wide bilateral suboccipital approach. The VA proximal to the aneurysm was occluded with an aneurysm clip using an approach from the right of the brainstem, while the VA distal to the aneurysm was occluded using a lateral suboccipital approach. When the VA and basilar artery are atherosclerotic and extremely tortuous, the distal and proximal aspects of the aneurysm can exist on both sides of the midline. In difficult cases such as that reported here, in which a giant VA aneurysm exceeded the midline of the anterior surface of the medulla, we believe that it is useful to employ a bilateral approach from both sides of the brainstem.

Treatment Strategies of Subarachnoid Hemorrhage from Bilateral Vertebral Artery Dissection: A Case Report and Literature Review Focusing on the Availability of Stent Placement

BACKGROUND

Bilateral vertebral artery dissection (VAD) may result in subarachnoid hemorrhage (SAH). However, a variety of factors contribute to the difficulties with treating SAH. We report a case of bilateral VAD with SAH, as well as a literature review.

CASE DESCRIPTION

A 32-year-old woman developed headache. Computed tomography demonstrated diffuse SAH, and 3-dimensional computed tomography indicated bilateral VAD. Her left vertebral artery was severely stenosed, and the basilar artery retrogradely flowed via the posterior communicating artery. Her bilateral VAD was trapped with the use of staged craniotomy. The postoperative course was uneventful for 13 days; however, severe neurologic deterioration remained in the area of the cerebral infarction, due to vasospasm of the internal carotid artery. This is the first report of hemorrhagic bilateral VAD treated with bilateral trapping and aggressive spasm treatment in the acute phase. However, the treatment was not successful.

CONCLUSIONS

Because of the increasing use of stent therapy, there has been a shift toward this treatment choice. For cases in which stents cannot be used, treatment methods based on prestenting protocols are helpful. A literature review indicated that conservative treatment for 2 weeks, in which vasospasm and rebleeding are controlled, may be considered compared with acute-stage stent treatment. Following our literature review, in situations in which stents cannot be used, only the ruptured side should be trapped with strict blood pressure control and detailed radiological images should be observed for 2 weeks. In conclusion, patient selection is essential to subject the patient to open surgery in such cases.

Reuse of a Reversed "Bone Pad" to Perforate Incompletely Penetrated Burr Holes Created by Automatic-Releasing Cranial Perforators

BACKGROUND

It can be difficult to make complete burr holes using a perforator with automatic releasing systems in cases of a soft diploe or thick calvarial bone.

OBJECTIVE

To demonstrate the utility of a flipped "bone pad" (BP) in recovery of penetration failure when using an automatic releasing perforator.

METHODS

For craniotomy or ventricular drainage, the first step is to make 1 or more burr holes using a craniotome. Neurosurgeons sometimes incompletely penetrate the skull using the latest tools. As a countermeasure for such cases, we have developed a simple and practical method. When making a perforation using a high-speed perforator, a round bone piece we call the BP is formed just above the dura. We pulled the BP from a completed burr hole, and placed the reversed BP in position at the bottom of the incompletely perforated burr hole. The BP acted as a new hard surface, preventing the automatic releasing system from activating, and allowed the burr hole to be completed by the craniotome without the need for additional tools.

RESULTS

With this technique, we have successfully completed 6 out of 7 imperfectly perforated burr holes using a perforator with an automatic releasing system. There were no technique-related complications, such as plunging or dural laceration.

CONCLUSIONS

The method has the advantage that the BP can be obtained without drilling an additional burr hole, and can be completed without the need for increasing cost, time, or instrument usage.