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.

Use of a Contest Format for Objective Assessment of Microsurgical Technique: An Observational Study.

BACKGROUND: Few studies have used simulation models to examine long-term improvement in microsurgical technique. We investigated whether improvement in surgical technique could be assessed by continuous, objective, contest-format evaluation of the same microsurgical task. METHODS: Since 2014, neurosurgeons with 1-10 years of experience participated in a biannual competition-format test. The task involved creating as many sutures as possible during the 5-minute interval after arteriotomy of a 1-mm artificial vessel. A modified version of the Objective Structured Assessment of Technical Skills examination was created and used. Changes and differences in scores over time were examined for each evaluator. RESULTS: Overall, 103 neurosurgeons participated in the study at least once, and those who participated more than once were divided into two groups: those who had the highest score in each contest and those who had the lowest score. The linear regression equations for the highest and lowest scorers were y=7.62x+81.56 (R2=0.628) and y=1.94x+67.93 (R2=0.0433), respectively. High scorers had high scores from the first time they participated, and their scores tended to increase further, while scores for low scorers tended not to increase with additional experience. Scores for the four evaluators did not significantly differ. CONCLUSIONS: Our results suggest that technical improvement in surgery can be assessed by long-term, continuous evaluation of microsurgical technique and that the present evaluation system might help increase surgical safety.

Vertebral artery V3 portion-radial artery-distal common carotid artery (V3-RA-dCCA) bypass for large basilar trunk aneurysm with bilateral proximal common carotid artery occlusion-technical note.

BACKGROUND: Large basilar trunk aneurysm caused by bilateral occlusion of the proximal common carotid artery is rare. We treated one case with vertebral V3 portion-radial artery-distal common carotid artery (V3-RA-dCCA) bypass. CASE DESCRIPTION: Basilar trunk aneurysm and bilateral occlusion of the proximal CCA were found incidentally in a 70-year-old woman. During the next 5 years, the aneurysm gradually enlarged to 12 mm, and blood flow of the anterior circulation was supplied through the posterior communicating artery. V3-RA-dCCA bypass was performed to reduce the stress of blood flow and prevent aneurysm growth and rupture. After exposing the neck portion, forearm of RA, and V3 portion of the vertebral artery, we created a space just below the sternocleidomastoid muscle to bypass the RA. We flushed the RA with albumin to stiffen the artery and temporarily clamped the bilateral sides of the RA to prevent twisting. We anastomosed the V3 and RA with a 9-0 thread and temporarily clamped the V3. After flushing the RA with albumin to prevent twisting, we clamped the external and internal carotid arteries, opened the dCCA with a vascular punch to prevent arterial dissection, and anastomosed the RA to the dCCA. The patency of the bypass was confirmed with Doppler and indocyanine green video angiography. The postoperative course was uneventful, bypass patency was good, and the aneurysm did not expand further. CONCLUSION: V3-RA-dCCA bypass may be an effective and low-risk treatment for large basilar trunk aneurysms with bilateral occlusion of the proximal common carotid artery.

Ring finger protein 213 c.14576G>A mutation is not involved in internal carotid artery and middle cerebral artery dysplasia.

The ring finger protein 213 (RNF213) susceptibility gene has been detected in more than 80% of Japanese and Korean patients with moyamoya disease (MMD), a bilateral internal carotid artery (ICA) occlusion. Furthermore, RNF213 has been detected in more than 20% of East Asians with atherosclerotic ICA stenosis. In this study, we evaluated the frequency of RNF213 mutations in congenital occlusive lesions of the ICA system. This case series was conducted jointly at four university hospitals. Patients with a family history of MMD, quasi-MMD, or related diseases were excluded. Ten patients were diagnosed with abnormal ICA or middle cerebral artery (MCA) angiogenesis. Patients with neurofibromatosis were excluded. Finally, nine patients with congenital vascular abnormalities were selected; of these, five had ICA deficiency and four had twig-like MCA. The RNF213 c.14576G > A mutation was absent in all patients. Therefore, the RNF213 c.14576G > A mutation may not be associated with ICA and MCA congenital dysplasia-rare vascular anomalies making it difficult to study a large number of cases. However, an accumulation of cases is required for accurate determination. The results of this study may help differentiate congenital vascular diseases from MMD.

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.

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.

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.

White Matter Lesions as Brain Frailty and Age are Risk Factors for Surgical Clipping of Unruptured Intracranial Aneurysms in the Elderly.

INTRODUCTION: We aimed to identify the risk factors for surgical treatment of unruptured intracranial aneurysms (UIAs) in individuals aged >60 years, particularly focusing on white matter lesions (WMLs). MATERIAL AND METHODS: We investigated a total of 214 patients with UIAs. The patient group comprised 53 males and 151 females with an average age of 68.2 years. UIA size ranged from 2.7 to 26 (mean: 7.3) mm. The primary endpoint of the study was patient prognosis evaluated at the time of discharge using the modified Rankin Scale. We examined the risk factors for poor outcome and WMLs using magnetic resonance imaging. RESULTS: Poor outcome was observed in 23 (10.7%) patients. Significant correlations were observed between poor outcome and UIA size (P < 0.0001), UIAs located posteriorly (P = 0.0204), UIA thrombosis (P = 0.0002), and presence of WMLs (P < 0.0001) in univariate regression analysis. However, no significant correlations were noted between poor outcome and age (P = 0.1438). Multivariate logistic regression analyses showed significant correlations between poor outcome and UIA size (P < 0.0001), presence of WMLs (P = 0.001). Severe WMLs based on the Fazekas classification was correlated to age (P < 0.0001) and atherosclerosis (P = 0.0001). Severe WMLs were associated with ischemia (P < 0.001) and epilepsy (P = 0.0502) as well as length of hospitalization (P < 0.0001). CONCLUSION: Severe WMLs are risk factors for surgical treatment of UIAs in the elderly. Surgical indications must be considered and caution should be taken when managing patients with severe WMLs.

Relationship between Flow-mediated Endothelial Vasodilation and the Pulse Wave Velocity, and Cervical Carotid Artery Stenosis.

Carotid artery stenosis is elicited by atherosclerosis and is the main cause of cerebral thrombosis. Flow-mediated endothelial vasodilation (FMD) can be measured noninvasively to assess vascular endothelial function related to atherosclerosis. The pulse wave velocity (PWV) is used to evaluate the vascular media involved in atherosclerosis. We investigated the relationship between these measurements in 75 consecutive patients with atherosclerotic cerebral thrombosis. They were assigned to three equal groups based on the severity of carotid artery stenosis on ultrasonograms. Group 1 had no stenosis, group 2 manifested moderate stenosis (<60%), and group 3 presented with severe stenosis (≥60%). We compared the FMD and PWV among the three groups. The PWV was significantly lower in group 1 than the other two groups. The FMD was significantly lower in group 3; it was significantly lower in group 2 than group 1. There was an inverse correlation between the FMD and the severity of carotid artery stenosis. Our findings show that for assessing the severity of carotid artery stenosis, the FMD is more useful than the PWV.

Subarachnoid Hemorrhage Attributable to Bilateral Aplastic or Twiglike Middle Cerebral Artery.

BACKGROUND: Aplastic or twiglike middle cerebral artery (MCA), a congenital anomaly related to the abnormal development of the MCA, is rare. It is usually unilateral; bilateral lesions are extremely rare. An aplastic or twiglike MCA may lead to cerebral ischemic stroke, intracranial hemorrhage, and subarachnoid hemorrhage (SAH). In patients with ischemic stroke due to hemodynamic stress, extracranial-intracranial (EC-IC) bypass surgery is indicated. As hemodynamic stress may also elicit SAH, it is important to select the appropriate treatment. EC-IC bypass surgery was successful in a patient with bilateral aplastic or twiglike MCA who suffered SAH due to hemodynamic stress. CASE DESCRIPTION: A 64-year-old female with a history of surgery for tetralogy of Fallot experienced SAH in the left sylvian fissure. As angiography showed a bilateral aplastic or twiglike MCA and single photon emission computed tomography revealed a decrease in the cerebral blood flow in the left MCA territory, we attributed her SAH to hemodynamic stress due to the decreased blood flow in the MCA territory and to the vulnerability of abnormal vessels as are seen in moyamoya disease. We performed EC-IC bypass surgery to reduce hemodynamic stress. A cerebral angiogram obtained 2 weeks postoperatively revealed sufficient blood flow in the MCA territory from the superficial temporal artery used for bypass. In the course of 2-year follow-up she remained stroke free. CONCLUSIONS: The presence of aplastic or twiglike MCA may lead to stroke due to hemodynamic stress. EC-IC bypass surgery may help to prevent stroke recurrence and SAH.

Incision of the anterior petroclinoidal fold during clipping for securing the proximal space of an internal carotid artery-posterior communicating artery aneurysm: a technical note.

Surgical clipping of an internal carotid artery (ICA)-posterior communicating artery (ICPC) aneurysm is often difficult in cases involving limited space to insert a clip at the proximal aneurysm neck hidden by the tent. In such cases, we perform incision of the anterior petroclinoidal fold to secure the proximal space for clip insertion. Between April 2013 and March 2018, we treated 89 ICPC aneurysm cases by clipping. Incision of the anterior petroclinoidal fold was performed in 15 of the 89 cases (16.8%). Fast imaging employing steady-state acquisition (FIESTA) magnetic resonance imaging (MRI) can indicate the locations of the aneurysm and tent and can help assess the need for tent incision. We widely dissected the distal sylvian fissure and sufficiently exposed around the aneurysmal space. We coagulated and cut the anterior petroclinoidal fold supra between the ICA and proximal neck of the aneurysm using a low-power bipolar system and needles or micro-scissors with care to avoid injury around structures such as the ICA, aneurysm, and oculomotor nerve. When using this strategy, we often select the Yasargil FT717 clip that has a curve along the skull base because of easy insertion. All cases showed complete aneurysm exclusion on three-dimensional computed tomography angiography, and there was no cerebral infarction, neurological deficit (such as hemiparesis), or oculomotor nerve palsy. Therefore, our strategy of incision of the anterior petroclinoidal fold during clipping for securing the proximal space of an ICA aneurysm is effective and safe.

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.

Neck haematoma after carotid endarterectomy: risks, rescue, and prevention.

OBJECTIVE: This study was performed to identify risk factors for neck haematoma requiring re-exploration after carotid endarterectomy. Neck haematoma is a well-known complication after carotid endarterectomy, but there has been little discussion about intraoperative techniques for its prevention. We also investigated an intraoperative neck flexion technique for prevention of neck haematoma. METHODS: A retrospective study reviewed 384 carotid endarterectomies performed at our institution from 2003 to 2016. The endpoint was neck haematomas requiring re-exploration after carotid endarterectomy. Endpoint predictors (general factors, preoperative medication, and intraoperative factors) were identified by univariate analysis. Our intraoperative neck flexion technique involved changing the neck and head position from extension to flexion during carotid endarterectomy. In patients with neck haematoma, we assessed the interval from carotid endarterectomy to re-exploration, the source of bleeding, and the method of airway rescue. RESULTS: There was one major and three minor perioperative strokes (1.1%). Neck haematoma occurred in 9 patients (2.4%). Univariate analysis (odds ratio [95% confidence interval]) identified preoperative clopidogrel therapy (4.19 [1.03-17.06], P = .04) and not using protamine sulfate after heparin (4.13 [1.02-25.06], P = .04) as risk factors for haematoma. We used the intraoperative neck flexion technique in 87 patients and no neck haematomas occurred. There was no additional morbidity and no mortality in the patients who required re-exploration. The interval between carotid endarterectomy and re-exploration ranged from 0 to 30 hours. Intubation before re-exploration was often difficult. We recommend using a laryngeal mask and performing minor wound re-exploration under local anesthesia before tracheal intubation for general anesthesia. Haematomas were mainly caused by venous bleeding or capillary oozing. CONCLUSIONS: This study showed that neck haematoma is uncommon after carotid endarterectomy, but requires emergency airway rescue and re-exploration.

Neck and Occipital Pain Caused by Deep Cervical Intramuscular Lipoma: A Surgical Case.

A lipoma is a slow-growing, benign tumor and is usually asymptomatic; hence, surgical intervention can often be avoided in patients with these tumors in the cervical and cranial area. Lipomas arise most commonly in the subcutaneous fat, but occasionally in muscle tissue. Intramuscular lipomas in the cervico-cranial area have rarely been reported. We describe here a patient with a large intramuscular lipoma in the deep cervical tissue. The patient experienced troublesome pain in the neck and occipital area, and surgical treatment was therefore suggested. Particularly in the cervical area, intramuscular lipomas sometimes invade the surrounding muscles and tissue layers and develop into an irregular mass, despite being benign. In addition, the cervical area has one of the most complex muscle structures. Nevertheless, surgical management of intramuscular lipoma in the cervical and cranial area is sometimes indicated, for example, in patients with clinical symptoms or masses with a tendency to grow large.

Recovery of Visual and Ophthalmologic Symptoms After Treating Large or Giant Internal Carotid Artery Aneurysm by High-Flow Bypass with Cervical Ligation.

OBJECTIVE: Large or giant internal carotid artery (ICA) aneurysms often cause visual deficits and cranial nerve palsy. The aim of this study was to investigate the efficacy of ligation of the ICA with high-flow bypass. METHODS: We retrospectively analyzed the findings from patients with visual deficit and ophthalmologic symptoms due to ICA aneurysms. In addition, we analyzed the recovery factors associated with the visual deficit and ophthalmologic symptoms postoperatively, focusing on the type of cranial nerve palsy, aneurysm size, location, and the time to treatment from first symptoms. RESULTS: We identified 38 patients (35 women, 3 men) with a mean age at surgery of 63.6 years (range, 24-81 years) with visual and ophthalmologic symptoms due to large or giant internal carotid aneurysm. Aneurysms ranged in size from 15-50 mm (mean, 25.2 mm). Visual disturbance (7 cases, 18%) and ophthalmoplegia (31 cases, 82%) were the only preoperative cranial nerve palsies. Aneurysms were completely thrombosed in 94.7% of cases (36/38). Visual disturbance improved in 28.5% of cases (2/7), and ophthalmoplegia improved in 87.1% of cases (27/31). Time to therapy from developing a visual disturbance was longer than time to therapy from developing ophthalmoplegia (P = 0.001). Time to therapy was significantly associated with recovery from cranial nerve palsy (P < 0.0001). The recovery of visual disturbance was worse than that of ophthalmoplegia (P = 0.001). CONCLUSION: Early treatment is recommended when the visual and ophthalmologic symptoms are present because treatment delay is a risk factor for nonimprovement of symptoms.

Long-term patency of superficial temporal artery to middle cerebral artery bypass for cerebral atherosclerotic disease: factors determining the bypass patent.

Long-term patency of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery for atherosclerotic disease and associated risk factors for loss of patency have rarely been discussed. We retrospectively analyzed long-term patency following STA-MCA bypass and evaluated various demographic and clinical factors to identify the ones predictive of postsurgical loss of patency using records of 84 revascularization procedures (58 patients, 45 males; mean age at surgery 63.6 years, range 31-78 years). Bypass patency was diagnosed based on magnetic resonance angiography or three-dimensional computed tomography. The mean follow-up period was 24.7 months (range 6-63 months). Decreased bypass patency was observed in 4 of 58 patients (6.9 %) who collectively underwent 6 bypasses (7.1 %) of 84. All cases of decreased bypass patency were first detected within 6 months of surgery. Bypass patency was not correlated with age, sex, number of anastomoses, postoperative cerebral infarction, or control of postoperative diabetes mellitus. We found a significant association of bypass patency with hyperperfusion (p = 0.01) and postoperative smoking (p = 0.0036). Furthermore, we found a significant association of hyperperfusion with STA diameter (p < 0.0001), location of anastomosis (p = 0.075), and preoperative cerebral blood flow (p = 0.0399). In our retrospective study, hyperperfusion and smoking after surgery may be risk factors for decreased bypass patency in cerebral atherosclerotic disease patients. Careful monitoring of patency to prevent hyperperfusion and cessation of smoking are recommended, particularly within 6 months of the surgery.

Intraoperative middle cerebral artery pressure measurements during superficial temporal artery to middle cerebral artery bypass procedures in patients with cerebral atherosclerotic disease.

OBJECTIVE No previous study has monitored middle cerebral artery (MCA) pressure during the superficial temporal artery (STA)-MCA bypass procedure for cerebral atherosclerotic disease. In this paper, the authors describe their method of monitoring MCA pressure and report their initial data on intraoperative MCA pressure and its relationship with hemodynamics prior to and after the bypass procedures. METHODS The results from a total of 39 revascularization procedures performed between 2004 and 2014 were analyzed. The patient group included 27 men and 12 women, and their mean age at surgery was 67.6 years (range 39-83 years). The authors investigated the MCA pressure via the STA during STA-MCA bypass procedures. After one branch of the STA was anastomosed to the MCA, the other branch was connected to an arterial line, and a clip was placed temporally on the main STA trunk to monitor the pre-anastomosis MCA pressure. Simultaneously, the radial artery (RA) pressure was determined before removing the temporal clip to measure the post-anastomosis MCA pressure. The relationship between MCA pressures and single photon emission computed tomography findings and the risk factors for hyperperfusion after STA-MCA bypass were analyzed. RESULTS The MCA/RA (%) pressure was significantly correlated with that of the resting stenotic/normal side cerebral blood flow (CBF) ratio (%) in the linear regression analysis (slope 1.200, r2 = 0.3564, F = 20.49, p < 0.0001). The intraoperative MCA pressure was 39.3% of RA pressure in patients with Powers' Stage 2 cerebral atherosclerotic disease. After 1 branch of the STA was anastomosed, the intraoperative MCA pressure increased to 75.3% of the RA pressure. The rate of increase in pressure was significantly correlated with the increase in the STA diameter in the linear regression analysis (slope 2.59, r2 = 0.205, F = 9.549, p = 0.0038). Hyperperfusion occurred in 2 cases. When mean values for these 2 patients were compared with those for the 37 patients without hyperperfusion, significant differences were found in the stenotic/normal side CBF ratio (p = 0.0001), pre-anastomosis MCA pressure (p = 0.02), rate of increase in pressure (p = 0.02), pre-anastomotic MCA/RA pressure ratio (p = 0.01), vascular reserve (p = 0.0489), and STA diameter (p = 0.0002). CONCLUSIONS The measurement of intraoperative MCA pressure may be a useful technique to assess cerebral perfusion and for predicting the risk of hyperperfusion. Monitoring MCA pressure is recommended during STA-MCA bypass procedures for atherosclerotic disease.

Indwelling Drains Are Not Necessary for Patients Undergoing One-level Anterior Cervical Fixation Surgery.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) has become a common procedure for cervical spine surgeries, since it is safe and effective in most patients. However, some patients develop life-threatening problems such as respiratory obstruction arising from rare postoperative hematoma and edema, although intraoperative bleeding caused by the connective tissue splitting procedure or bleeding caused by postoperative insertion of a suction tube has rarely been reported. Investigation of the requirement for indwelling drains in patients who undergo cervical spine surgery is necessary because of the pain, anxiety, and discomfort caused despite the use of high-quality materials. METHODS: Enrolled in the study were 43 patients who underwent one-level anterior cervical fixation surgery, including 23 (randomly selected) who received an indwelling drain (group A, mean age: 57.78±14.46 years, range: 39-82 years, male/female: 13/10), and 20 who received no indwelling drain (group B, mean age: 57.00±13.99 years, range: 29-81 years, male/female: 12/8). Intraoperative bleeding amounts, lateral views of plain cervical spine radiographs, prevertebral space (PVS) changes on plain radiographs and computed tomography (CT) images, wound inspections, and pain assessments on the Numeric Rating Scale (NRS) were compared between groups. In addition, a history of risk factors for bleeding, such as hypertension, diabetes, and cerebrovascular diseases which require antiplatelet therapy, was determined. Hepatic failure was observed in none of the patients. RESULTS: Postoperative CT images obtained the day following surgery showed no densities indicating the presence of postoperative hematoma in any of the 43 patients. The maximum amount of intraoperative bleeding was 10 mL, with no significant difference between groups. No patients reported an obvious pain level on NRS, but the pain was significantly milder in group B (A: 1.326±0.911, B: 0.555±0.556, p=0.0037). The postoperative PVS increment on plain radiographs was comparable between groups (A: 1.778±0.992, B: 1.730±0.966, p=0.8728). DISCUSSION: Given the negligible intraoperative and postoperative bleeding observed in both groups, and the lack of difference in PVS increments between the groups, our results suggested that indwelling drains are not required for patients undergoing typical anterior cervical fixation surgery. However, it is important to take care of major vessels such as the superior and inferior thyroid arteries and the external jugular vein as well as the prevertebral venous plexus during surgery.

Technical arrangement of the Williams-Isu method for anterior cervical discectomy and fusion.

Anterior cervical fixation with autologous bone transplantation-without the need for harvesting bone from other sites, such as the ilium-was developed by Williams and modified by Isu et al. In recent intervertebral fusion procedures, after harvesting the cuboid bone from vertebral bodies, a hydroxyapatite block is placed between two harvested vertebral bones in the same way as in the sandwich method for intervertebral fixation. According to previous studies, this procedure has the following disadvantages: (i) as the corrective force for cervical kyphosis is insufficient, it could not be adapted for patients with preoperative kyphosis; (ii) special devices, including a microsurgical saw, are required for harvesting vertebral bones. In our modified method, we used a conventional high-speed drill instead of a microsurgical saw. Nevertheless, the results show that the operated spine can be stabilized to a greater extent by decreasing the height of the grafted bone, and this might help in reducing postoperative kyphosis.

Observation of vocal fold and pharyngeal paralysis after carotid endarterectomy using a magnifying laryngoscope.

BACKGROUND: Injury to the vagus nerve or one of its branches during carotid endarterectomy (CEA) can result in vocal fold paralysis (VFP), but the exact mechanisms and site of injury responsible for VFP after CEA are unclear. The aim of this study was to identify the site of nerve injury in patients with VFP after CEA using magnifying laryngoscopy. METHODS: We performed 96 consecutive CEA procedures in 87 patients over 5 years. After 56 CEA procedures, we examined vocal fold movements with a flexible nasolaryngoscope and detected VFP in 5 of 40 cases (9 %). At 6-8 weeks after CEA, these five patients also underwent magnifying laryngoscopy at another institution by a specialist in vocalization. RESULTS: We confirmed ipsilateral VFP and pharyngeal paralysis in three patients. The other two patients recovered from their nerve injuries spontaneously before the magnifying examination. CONCLUSIONS: VFP and pharyngeal paralysis were caused by damage to the recurrent laryngeal and pharyngeal nerves. Therefore, the probable site of nerve injury during CEA was near the inferior vagal ganglion of the vagus nerve trunk in our three patients.