Therapeutic Occlusion Research Articles

Tubridge flow diverter for the treatment of recurrent cerebral aneurysms

Background & Objective: The Tubridge flow diverter is a commonly used device in China for reconstructing the parental artery and occluding complex intracranial aneurysms. However, there is limited experience with the device in treating recurrent intracranial aneurysms. The purpose of this study is to assess the safety and effectiveness of the Tubridge flow diverter in treating recurrent single- coiling aneurysms. Methods: The clinical records of patients with recurrent intracranial aneurysms who were treated with a Tubridge flow diverter were reviewed to show the therapeutic process, occlusion rate, and clinical outcomes associated with this treatment method. Results: Five patients with recurrent aneurysms of the internal carotid artery after singe coiling were included in the study. The recurrent aneurysmal sac had a mean length and width of 8.34/4.30 mm. All five Tubridge flow diverters were implanted without any unfold failure. The last angiographic follow-up showed a complete occlusion rate of 100%. Five branch arteries were covered, and only one branch artery disappeared during follow-up. No cases of cerebral infarction or intracranial hemorrhage were found among the patients. Conclusions: Our initial findings indicate that the Tubridge flow diverter could be a reliable and successful method for treating recurring single-coil aneurysms. We observed that the branch arteries were well-preserved, and no patients experienced cerebral infarction or hemorrhage. However, further research is necessary to establish clear indications and potential complications through a multicenter randomized controlled trial with long-term follow-up.

Effective myocardial infarction treatment by targeted accumulation of Sulforaphane using porous magnetic silica nanoparticles

Myocardial infarction (MI) is a common cardiovascular pathology that induces extensive sterile inflammation during its early stages, posing a severe threat to human health. Effectively modulating cardiac inflammation may improve post-MI outcomes. Unfortunately, owing to the side effects of therapeutic drugs and cardiac coronary artery occlusion, current MI drugs are sub-optimal for the clinical management of ischemic myocardia. Sulforaphane (SFN) has been adopted for MI treatment due to its myocardial protective effects and low toxicity. However, the targeted accumulation of SFN in infarcted areas remains challenging. Herein, porous magnetic silica nanoparticles (PMSNs) were synthesized and loaded with SFN to improve the specificity of targeted SFN delivery to infarcted areas in mouse models of MI. PMSNs loaded with SFN (PMSNs + SFN) decreased the levels of pro-inflammatory cytokines, thus leading to the improvement of cardiac function and cell survival without adverse effects. To further explore SFN’s mechanisms of action in MI, a cellular (in vitro) model was established via oxygen and glucose deprivation (OGD). HSF1 and Nrf2 knockdown resulted in a decrease of SFN-induced HSP70 expression in OGD cells. Moreover, as a result of HSP70 knockdown, the pro-survival and anti-inflammatory effects of SFN were blocked in OGD cells. The level of pro-inflammatory cytokines decreased upon HSP70 overexpression, and cell survival rate increased under OGD conditions. In summary, the results confirm that PMSNs are capable of transporting SFN to infarcted areas in the myocardium, where the drug exerts cardioprotective effects against myocardial injury by up-regulating HSP70 through Nrf2/HSF1.

Tubridge flow diverter for the treatment of small and medium aneurysms.

Tubridge flow diverter is a widely used device aimed at reconstructing parent arteries and occluding complex aneurysms in China. The experience of Tubridge in treating small and medium aneurysms is still limited. In this study, we aimed to evaluate the safety and efficacy of the Tubridge flow diverter for the treatment of the two types of aneurysms. We reviewed the clinical records of aneurysms treated with a Tubridge flow diverter between 2018 and 2021 in a national cerebrovascular disease center. Cases were divided into small and medium aneurysms according to aneurysm size. The therapeutic process, occlusion rate, and clinical outcome were compared. In total, 57 patients and 77 aneurysms were identified. The patients were divided into two groups: small aneurysms (39 patients, 54 aneurysms) and medium aneurysms (18 patients, 23 aneurysms). There were 19 patients with tandem aneurysms (a total of 39 aneurysms) in the two groups, among which 15 patients (30 aneurysms) were in the small aneurysm group and four patients (nine aneurysms) were in the medium aneurysm group. The results show that the mean maximal diameter/neck in the small and medium aneurysms was 3.68/3.25 and 7.61/6.24 mm, respectively. In total, 57 Tubridge flow diverters were successfully implanted without unfolding failure, and there were six patients with new mild cerebral infarction in the small aneurysm group. The complete occlusion rate on the last angiographic follow-up was achieved in 88.46% of the small aneurysms group and 81.82% of the medium aneurysms group. The complete occlusion rate of patients with tandem aneurysms in the last angiographic follow-up was 86.67% (13/15) of the small aneurysms group and 50% (2/4) of the medium aneurysm group. Intracranial hemorrhage was nonencountered in the two groups. Our preliminary experience suggests that the Tubridge flow diverter might be a safe and effective treatment for small and medium aneurysms along the internal carotid artery. Long stents may increase the risk of cerebral infarction. Adequate evidence is required to clarify the definite indications and complications in a multicenter randomized controlled trial with a long-term follow-up.

Perioperative and long-term complications following therapeutic internal carotid artery occlusion.

Parent artery occlusion (PAO) is an effective treatment for hemorrhagic diseases associated with the internal carotid artery. There are several reports of long-term cerebral infarction or the formation of de novo cerebral aneurysms following PAO. We retrospectively reviewed these complications in 38 patients who underwent PAO for therapeutic treatment. We investigated perioperative cerebral infarctions, long-term cerebral infarctions, and de novo aneurysms. The mean age of the patients was 64.0 years, and 25 patients (65.8%) were female. The causative diseases were unruptured (n = 19; 50.0%) and ruptured (n = 8; 21.1%) aneurysms. PAO was performed after ischemic tolerance was assessed with balloon test occlusion (BTO), and BTO was performed in 34 patients, of whom 25 (73.5%) had ischemic tolerance. Twenty-six patients (68.4%) were treated with PAO alone, eight (23.5%) with low-flow bypass, and six (17.6%) with high-flow bypass. Perioperative complications occurred in five patients (13.2%): two of the 26 patients (7.7%) who underwent scheduled treatment and three of the 12 patients (25.0%) who underwent emergency treatment. One patient (2.6%) had long-term de novo aneurysm, and none developed cerebral infarction. These results showed that the assessment of ischemic tolerance by performing BTO and appropriate revascularization in scheduled treatments are important to reduce perioperative and long-term cerebral infarctions. PAO must be performed with greater caution in emergency treatment.

Balloon Test Occlusion of Internal Carotid Artery in Recurrent Nasopharyngeal Carcinoma Before Endoscopic Nasopharyngectomy: A Single Center Experience.

ObjectivesEndoscopic nasopharyngectomy (ENPG) is a promising way in treating recurrent nasopharyngeal carcinoma (rNPC), but sometimes may require therapeutic internal carotid artery (ICA) occlusion beforehand. Balloon test occlusion (BTO) is performed to evaluate cerebral ischemic tolerance for ICA sacrifice. However, absence of neurological deficits during BTO does not preclude occur of delayed cerebral ischemia after permanent ICA occlusion. In this study, we evaluate the utility of near-infrared spectroscopy (NIRS) regional cerebral oxygen saturation (rSO2) monitoring during ICA BTO to quantify cerebral ischemic tolerance and to identify the valid cut-off values for safe carotid artery occlusion. This study also aims to find out angiographic findings of cerebral collateral circulation to predict ICA BTO results simultaneously.Material and Methods87 BTO of ICA were performed from November 2018 to November 2020 at authors’ institution. 79 angiographies of collateral flow were performed in time during BTO and classified into several Subgroups and Types according to their anatomic and collateral flow configurations. 62 of 87 cases accepted monitoring of cerebral rSO2. Categorical variables were compared by using Fisher exact tests and Mann–Whitney U tests. Receiver operating characteristic curve analysis was used to determine the most suitable cut-off value.ResultsThe most suitable cut-off △rSO2 value for detecting BTO-positive group obtained through ROC curve analysis was 5% (sensitivity: 100%, specificity: 86%). NIRS rSO2 monitoring wasn’t able to detect BTO false‐negative results (p = 0.310). The anterior Circle was functionally much more important than the posterior Circle among the primary collateral pathways. The presence of secondary collateral pathways was considered as a sign of deteriorated cerebral hemodynamic condition during ICA BTO. In Types 5 and 6, reverse blood flow to the ICA during BTO protected patients from delayed cerebral ischemia after therapeutic ICA occlusion (p = 0.0357). In Subgroup IV, absence of the posterior Circle was significantly associated with BTO-positive results (p = 0.0426).ConclusionAngiography of cerebral collateral circulation during ICA BTO is significantly correlated with ICA BTO results. Angiographic ICA BTO can be performed in conjunction with NIRS cerebral oximeter for its advantage of being noninvasive, real-time, cost-effective, simple for operation and most importantly for its correct prediction of most rSO2 outcomes of ICA sacrifice. However, in order to ensure a safe carotid artery occlusion, more quantitative adjunctive blood flow measurements are recommended when angiography of cerebral collateral circulation doesn’t fully support rSO2 outcome among clinically ICA BTO-negative cases.

Treatment of Serious Occlusal Instability Associated with Temporomandibular Disorders (TMDs) Through Implant and Dynamic Occlusal Schemes Rehabilitation. A Case Report

A case report of 35 years old male patient, partially edentulous with occlusal instability, Disc Displacement with Reduction (DDWR), Local Muscle Soreness (LMS) and Alteration of vertical dimension is presented. Rehabilitation was planned to achieve predictability of long-term treatment, providing static and dynamic occlusal stability. A therapeutic occlus ion with premature contact in the right premolar sector was planned. Implants and cemented/screwed crowns were used to obtain contacts in the molar area. The restoration of dynamic occlusal schemes was made by direct adhesive technique in the anterior sector and Curve of Spee (COS) compensation with temporary anchoring for molar inclusion was used. Patient presents objective and subjective improvements associated with the treatment performed. Temporomandibular disorder is stabilized and controlled by a specialist.

Endovascular Treatment of Carotid Blowout Syndrome

BackgroundCarotid blowout syndrome (CBS) is a life-threatening disease characterized by compromise of the carotid artery by head and neck cancer (HNC). Materials and methodsWe reviewed the characteristics and outcomes of all patients with carotid blowout syndrome who were treated between April 2010 and December 2019. Twelve patients with a history of HNC and radiation therapy were investigated. The balloon occlusion test (BOT) was performed in all patients to confirm collateral circulation. We placed a stent in patients who were intolerant to the BOT. ResultsThe patients’ ages ranged from 50 to 81 years (mean: 68.1 years). Therapeutic occlusion of the affected internal carotid artery was performed in nine patients, while stenting was performed in three patients. Immediate hemostasis was achieved in all patients. Patients treated using stents were administered perioperative DAPT. One patient experienced rebleeding after surgery. Two patients had procedure-related cerebral infarctions. One patient died, but the others survived without major neurological deficits. One patient had persistent aneurysm after surgery that resolved over time. ConclusionEndovascular treatment via occlusion or stent-based reconstruction of the internal carotid artery resulted in immediate hemostasis. Carotid occlusion and covered stent application are safe and efficient techniques to treat CBS secondary to HNC. Surgeons may obtain better outcomes if they perform BOT before occlusion and design treatment accordingly.

Extracranial vertebral artery to middle cerebral artery bypass in therapeutic internal carotid artery occlusion for epipharyngeal carcinoma: A technical case report.

Background: Vertebral artery (VA) to middle cerebral artery (MCA) bypass is a rarely selected technique because a complex expanded dissection is required, and often, a better donor artery than VA exists. A good indication for VA-MCA bypass is the treatment of head-and-neck malignancies with the sacrifice of the internal carotid artery (ICA) or for carotid artery rupture.Methods: A 23-year-old man with epipharyngeal carcinoma, treated by ligating the carotid artery with a VAMCA bypass before chemoradiotherapy, was reported. Radiographic findings showed that the bone of the carotid canal was dissolved, and the right ICA was engulfed by the tumor. As epipharyngeal carcinoma is hypersensitive to radiation, in cases where the tumor rapidly disappears, ICA may dangle in the pharynx and rupture may occur. In addition, to irradiate sufficiently, the ICA may become an obstacle. Hence, we decided to perform carotid ligation with a VA-MCA bypass before radiation and chemotherapy for the primary lesion. We selected the V3 portion of the VA as the donor on the ipsilateral side, as it can supply high-flow cerebral blood flow, which is not influenced by carcinoma and less influenced by irradiation for the epipharynx.Results: The VA-MCA bypass was completed without complications followed by endovascular occlusion of the ICA. Induction chemotherapy was initiated for the patient 2 weeks after surgery. The patient achieved a complete response following chemoradiotherapy.Conclusion: ICA ligation with VA-MCA high-flow bypass earlier than chemoradiotherapy is useful for epipharyngeal carcinoma as it prevents carotid artery rupture and allows radical intervention.

Mediotrusive Occlusal Contacts: Best Evidence Consensus Statement.

The impact of mediotrusive (MT) occlusal contacts has been a topic of controversy and confusion in both clinical practice and in the dental literature. The purpose of this Best Evidence Consensus Statement was to explore whether MT interferences are harmful in the natural or therapeutic occlusion directed by 4 focus questions relating to prevalence, jaw function, jaw dysfunction and biomechanical models. An electronic search in October 2020 sought evidence in MEDLINE (Ovid) using (mediotrus* OR nonworking side OR nonworking contact OR balancing side OR interfer* side OR premature contact) in the multipurpose (.mp) search field; and in Google Scholar using permutations of the above. Supplementary articles were sourced from the associated reference lists. There was no language restriction. The search yield was reviewed in duplicate. The electronic search identified 420 articles. Following screening, 164 were selected for eligibility assessments. Of these, 47 were included in the current paper. Non-standardized nomenclature and methodology is used to identify MT interferences in patient populations, with resultant prevalence varying from 0% to 77%, (median = 16%). MT interferences may alter the biomechanics of mandibular function. Together with the presence of repeated high loads resultant strain can manifest as pathophysiology of the temporomandibular joint and associated muscle structures. MT interferences should be avoided in any therapeutic occlusal scheme to minimize pulpal, periodontal, structural and mechanical complications or exacerbation of temporomandibular disorders (TMDs). Naturally occurring molar MT interferences should be eliminated only if signs and symptoms of TMDs are present. Literature supports there being a biomechanical basis which can explain how MT interferences may affect temporomandibular joint morphology and jaw function.

Effect of Resistance Exercise with Blood Flow Restriction on Peripheral Oxygen Saturation and Cardiovascular Stress in Untrained Diabetic Women: A Cross and Randomized Study

This study aimed to analyze the effects of high-load (HL) resistance exercise (RE), low-load (LL) RE, and LL RE with blood flow restriction (LL + BFR) in peripheral oxygen saturation level (SpO2), heart rate (HR), and double product (DP: HR × systolic blood pressure [SBP]) in untrained women with type 2 diabetes (T2DM). Ten untrained women with T2DM (Age = 56.9 ± 7.4 years; BMI = 27.2 ± 4.2 kg/m2; and Diagnostic time = 10.6 ± 4.1 years) participated in this study. Participants attended a local gym for four non-consecutive days. During the first visit, arterial occlusion pressure (AOP) and predictive values of one maximum repetition (1RM) for knee extension exercise (KE) were assessed. The second, third, and fourth visits were randomly assigned to the following: HL RE (~65% of predicted 1RM in 3 sets of 10 repetitions), LL RE (~20% of predicted 1RM in 3 sets of 15 repetitions), and LL + BFR RE (~20% of predicted 1RM in 3 sets of 15 repetitions; 50% of AOP). HR, SBP e SpO2 were assessed before and immediately after each protocol. All protocols significantly increased the analyzed variables (p ≤ 0.05). There were no significant differences in hemodynamic responses between the protocols (p > 0.05). Therefore, resistance exercise with BFR seems to promote cardiovascular responses similar to traditional low and high load resistance exercise protocols in untrained diabetic women. Keywords: Double Product, Heart Rate, Ischemia, Hemodynamics, Kaatsu training, Resistance Training, Therapeutic Occlusion. Read more →

Neurotrophic keratitis in autoimmune polyglandular syndrome type 1: a case report

BackgroundAutoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive disease. In patients with APS-1, the most frequently reported ocular manifestations are keratoconjunctivitis with dry eye and retinal degeneration. However, to our knowledge, no research studies have reported the relationship between APS-1 and neurotrophic keratitis (NK). Possible explanations such as limbus cell deficiency being the primary cause of APS-1 keratopathy are not applicable to our unusual case of the patient with APS-1 presenting as ocular surface disease with NK. Our case findings suggest a new explanation for the observed corneal pathology and a potential treatment for these patients.Case presentationA 27-year-old woman was referred to our hospital because of intermittent blurred vision and recalcitrant ocular surface problems in both eyes for many years. She has a history of autoimmune polyglandular syndrome type 1 (APS-1), which includes hypothyroidism, hypoparathyroidism, hypoadrenalism, and hypogonadotropic hypogonadism. In vivo confocal microscopy clearly demonstrated significant degeneration of the sub-basal nerve plexus and stromal nerve bundles in her corneas bilaterally. She was diagnosed with severe NK and ocular surface disease caused by dry eye. Treatment included the application of therapeutic soft contact lenses and punctual occlusion; however, both treatments had a limited effect.ConclusionPatients with APS-1 may have ocular surface disease and severe damage to corneal nerves. Regular follow-up and treatment focusing on the regeneration of corneal nerves is particularly important in these patients.

Orthodontic Treatment by Compensation of a Skeletal Class III Associated with Mandibular Laterognathy: Aesthetic Challenge and Therapeutic Occlusion

Introduction: This case report describes compensatory orthodontic treatment in a young patient aged 13 years. She presented with a class III skeletal malocclusion associated with mandibular laterognathy. The patient's main reason for consultation was the anterior cross bite and the aesthetics of her smile.Materials and Methods: The chosen treatment was therefore an orthodontic camouflage with the extraction of the first mandibular premolars and the second maxillary premolars, in order to catch a correct anterior articular and restore a good occlusal relationship, however, the mandibular laterognathy was camouflaged by means of dental compensations and also by correcting the deviation of the incisors medians through a class III mechanics with good anchorage management.Results: After 24 months of treatment, an ideal overjet and overbite associated with a Class I canine and molar relationship, was obtained, associated with a perfect coincidence of the interincisor medians.Conclusion: Class III skeletal cases can often be treated either by orthodontic camouflage or surgery. In our case study, the treatment adopted was orthodontic camouflage with extractions. The results of the treatment were satisfactory and the occlusal objectives were achieved. The final harmonious smile pleased the patient and improved her self-esteem and quality of life.

Therapeutic occlusion of the internal mammary arteries to relieve refractory angina

Therapeutic occlusion of the internal mammary arteries to relieve refractory angina

The blood flow restriction training effect in knee osteoarthritis people: a systematic review and meta-analysis

Objective: To synthesize evidence on the effects of blood flow restriction (BFR) comparing with high (HLT) and low load (LLT), and on the influence of different forms of application in individuals with knee osteoarthritis. Data sources: The CENTRAL, PEDro, PubMed and BVS, which include Lilacs, Medline and SciELO, until April 2020. Review methods: A systematic review and meta-analysis of randomized trials used the PRISMA guidelines, whose main keywords were: Therapeutic Occlusion, Resistance Training, and Knee Osteoarthritie, blood flow restriction and Kaatsu training. Method quality was evaluated with the PEDro scale. When studies demonstrated homogeneity on outcome measures, the mean differences or standardized mean differences with 95% confidence interval were calculated and pooled in a meta-analysis for pooled synthesis. Results: Five articles were eligible in this review with moderate to low risk bias. Our results, showed no difference between BFR and HLT in knee strength (SMD = 0.00, 95% CI, –0.54 to 0.54, P = 1.00), function (SMD = −0.20, 95% CI, –0.45 to 0.06, P = 0.13), pain and volume. But, when compared BFR and LLT, the descriptive analysis demonstrated significant results in favor BFR to muscle strength (71.4% of measurement) and volume (MD = 1.66, 95% CI, 0.93 to 2.38, P < 0.00001), but not in pain or function. Conclusion: BFR can be used as a strategy in the rehabilitation of osteoarthritis due to gains in strength and volume with low mechanical stress. However, its application must be safe and individualized, since they can attenuate the stimuli offered by BFR.

Treatment monitoring and innovations in amblyopia treatment

Technical innovations, such as computer games and shutter glasses open up elegant treatment options for amblyopia. The lack of monitoring of compliance means that there is no scientific basis on which acomparative study between anew therapeutic approach and occlusion therapy as the standard of care could be designed. An easy to use microsensor for measurement of compliance could have a broad spectrum of applications in scientific studies as well as in routine clinical practice. This article gives abrief overview about emerging and innovative approaches.

Evaluation of Balloon Test Occlusion Before Therapeutic Carotid Artery Occlusion: Flat Detector Computed Tomography Cerebral Blood Volume Imaging versus Single-Photon Emission Computed Tomography

We aimed to compare flat detector computed tomography cerebral blood volume (FD-CBV) imaging to single-photon emission computed tomography (SPECT) as an adjunctive technique during balloon test occlusion (BTO) in patients with intracranial aneurysms or tumors. Twelve patients who underwent SPECT (99mTc-ethyl cysteinate dimer) and FD-CBV imaging during BTO were enrolled. Color-coded cerebral blood flow (CBF) images and color-coded FD-CBV images were generated and visually inspected whether there were asymmetries between the ipsilateral and contralateral cerebral hemispheres. Region of interest measurements were performed on the color-coded images at the same locations for both modalities. The mean interhemispheric region of interest ratios were calculated, and the ratio between these were estimated using linear regression models. Ten patients had no symptoms during BTO. Two patients developed subtle but inconclusive neurologic changes approximately 10 minutes after balloon inflation; their images showed asymmetric color-coded images with decreased CBF and FD-CBV in the ipsilateral hemisphere. The mean interhemispheric ratio of CBF was significantly smaller in patients with subtle changes than in those without (0.84 vs. 0.98; P < 0.001). Similarly, the mean interhemispheric ratio of FD-CBV was significantly smaller in patients with subtle changes than in those without (0.88 vs. 1.06; P= 0.01). No patient showed increased CBF or FD-CBV in the ipsilateral hemisphere. The patients with decreased CBF on SPECT also showed decreased FD-CBV in the ipsilateral hemisphere. FD-CBV imaging may be useful as an adjunctive technique for BTO before potential therapeutic carotid artery occlusion.

Effects of blood flow restriction exercises on bone metabolism: a systematic review.

This study analysed the effect of low-intensity (LI) exercises with blood flow restriction (BFR) on bone metabolism compared with high-intensity (HI) exercises without BFR. The following databases were searched using the keywords therapeutic occlusion training OR BFR training OR vascular occlusion training OR KAATSU training OR ischaemia training AND osteogenesis OR bone biomarkers OR bone metabolic marker OR bone mass OR bone turnover OR osteoporosis OR osteopenia: PubMed, Web of Science, SPORTDiscus, CINAHL, Science Direct, Cochrane and Google Scholar. Two researchers, independently and blindly, selected the studies based on established inclusion and exclusion criteria. Electronic and manual searches located 170 articles published in English; after screening, only four studies showed that BFR training increases the expression of bone formation markers (e.g. bone-specific alkaline phosphatase) and decreases bone resorption markers (e.g. the amino-terminal telopeptides of type I collagen) after both aerobic and anaerobic exercise across several populations. The results of this study show that few studies have confirmed the positive effect of exercise with BFR on bone metabolism, formation and resorption. Furthermore, no methodological standardization of the samples, exercise type, intervention frequency or duration was observed.

Cerebral infarction caused by accidental incarceration of aneurysm-adjacent branches with temporary clips

Objective To explore the potential reasons of cerebral infarction caused by accidental incarceration of aneurysm-adjacent branches with temporary clips, and to give guidance to the appropriate application of temporary clips. Methods A retrospective analysis was conducted on the clinical data of 10 patients with accidental incarceration of branches of parent artery or aneurysm-adjacent perforator vessels who were admitted to Department of Neurosurgery of Fuzhou General Hospital from January 2004 to December 2016. Under microscopes, we observed the definite lesions of branches and perforator vessels during the procedures, features of temporary clips and the intraoperative procedure, and postoperative cerebral infarction with varying degrees in corresponding territories. Two cases of posterior communicating artery aneurysm and 2 cases of carotid bifurcation aneurysm were found on the extracranial superior mesenteric artery adventitia with varying degrees of atherosclerosis, misclipping occurred at the anterior pre-choroidal artery, recurrent artery of Heubner and lenticulostraiate artery. For 4 cases of anterior communicating artery aneurysms and 2 cases of middle cerebral artery aneurysm, mis-clipping was found at A1 or A2 and M1 segments adjacent to perforation. Results Among the 10 patients, CT review 2-4 days post surgery demonstrated cerebral infarction with varying degrees adjacent to the aneurysm branches, perforating branch of blood supply. Disturbance of consciousness occurred in 2 cases. Compared with preoperative state, short-term significant decrease in strength of limb muscles was observed in 5 cases, incomplete motor aphasia in 1 and asymptomatic cerebral infarction in 2. At follow-up ranging from 4 months to 3 years, 2 cases reported dementia and 2 cases had permanent hemiplegia, out of which 3 were disabling and needed long-term care. Conclusions Cerebral infarction caused by accidental incarceration of branches or perforator vessels with temporary clips could be related not only to the incarceration duration, age and vascular sclerosis, but also to the over-contraction of small blood vessels and the closing force of a temporary clip. Therefore, caution should be warranted regarding those factors in the use of temporary clips. Key words: Intracranial aneurysm; Vascular system injuries; Therapeutic occlusion; Brain infarction

Graft Occlusion and Graft Size Changes in Complex Internal Carotid Artery Aneurysm Treated by Extracranial to Intracranial Bypass Using High-Flow Grafts with Therapeutic Internal Carotid Artery Occlusion.

Although the extracranial-to-intracranial high-flow bypass (EC-IC HFB) continues to be indispensable for complex aneurysms, the risk factors for the graft occlusion and whether the graft size changes after the bypass have not been well established. To evaluate the risk factors for the graft occlusion and to confirm whether graft diameters changed over time. The data of 75 patients who suffered from complex internal carotid artery (ICA) aneurysms and were treated by EC-IC HFB using radial artery graft (RAG) or saphenous vein graft (SVG) with therapeutic ICA occlusion were evaluated. Clinical and radiological characteristics were compared in patients with and without the graft occlusion by the log-rank test. Graft diameters measured preoperatively, postoperatively, at 6 months, and at 1 year were compared by paired t-test. During a follow-up period (median 26.2 months), graft occlusions were seen in 4 patients (5.3%), and these were the SVGs. Only SVG was related to graft occlusion (P < .001). There was a significant increase with time in RAG diameters (preoperative, 3.1 ± 0.41 mm; postoperative, 3.6 ± 0.65 mm; 6 months, 4.3 ± 1.0 mm; 1 year, 4.4 ± 1.0 mm), while there were no significant diameter changes in SVGs. The present study showed that the SVG was related to the graft occlusion and RAGs gradually enlarged. Unless Allen test is negative, RAG may be better to be used as a graft in EC-IC HFB if therapeutic ICA occlusion is needed.

Rationale for graft selection in patients with complex internal carotid artery aneurysms treated with extracranial to intracranial high-flow bypass and therapeutic internal carotid artery occlusion.

OBJECTIVE After internal carotid artery (ICA) sacrifice without revascularization for complex aneurysms, ischemic complications can occur. In addition, hemodynamic alterations in the circle of Willis create conditions conducive to the formation of de novo aneurysms or the enlargement of existing untreated aneurysms. Therefore, the revascularization technique remains indispensable. Because vessel sizes and the development of collateral circulation are different in each patient, the ideal graft size to prevent low flow-related ischemic complications (LRICs) in external carotid artery (ECA)-middle cerebral artery (MCA) bypass with therapeutic ICA occlusion (ICAO) has not been well established. Authors of this study hypothesized that the adequate graft size could be calculated from the size of the sacrificed ICA and the values of MCA pressure (MCAP) and undertook an investigation in patients with complex ICA aneurysms treated with ECA-graft-MCA bypass and therapeutic ICAO. METHODS In the period between July 2006 and January 2016, 80 patients with complex ICA aneurysms were treated with ECA-MCA bypass and therapeutic ICAO. Preoperative balloon test occlusion (BTO) was performed, and the BTO pressure ratio was defined as the mean stump pressure/mean preocclusion pressure. Low flow-related ischemic complications were defined as new postoperative neurological deficits and ipsilateral cerebral blood flow reduction. Initial MCAP (iMCAP), MCAP after clamping the ICA (cMCAP), and MCAP after releasing the graft (gMCAP) were intraoperatively monitored. The MCAP ratio was defined as gMCAP/iMCAP. Based on the Hagen-Poiseuille law, the expected MCAP ratio ([expected gMCAP]/iMCAP) was hypothesized as follows: (1 - cMCAP/iMCAP)(graft radius/ICA radius)2 + (cMCAP/iMCAP). Correlations between the BTO pressure ratio and cMCAP/iMCAP, and between the actual and expected MCAP ratios, were evaluated. Risk factors for LRICs were also evaluated. RESULTS The mean BTO pressure ratio was significantly correlated with the mean cMCAP/iMCAP (r = 0.68, p < 0.0001). The actual MCAP ratio correlated with the expected MCAP ratio (r = 0.43, p < 0.0001). If the expected MCAP ratio was set up using the BTO pressure ratio instead of cMCAP/iMCAP (BTO-expected MCAP ratio), the mean BTO-expected MCAP ratio significantly correlated with the expected MCAP ratio (r = 0.95, p < 0.0001). During a median follow-up period of 26.1 months, LRICs were observed in 9 patients (11%). An actual MCAP ratio < 0.80 (p = 0.003), expected MCAP ratio < 0.80 (p = 0.001), and (M2 radius/graft radius)2 < 0.49 (p = 0.002) were related to LRICs according to the Cox proportional-hazards model. CONCLUSIONS Data in the present study indicated that it was important to use an adequate graft to achieve a sufficient MCAP ratio in order to avoid LRICs and that the adequate graft size could be evaluated based on a formula in patients with complex ICA aneurysms treated with ICAO.