Mechanical Thrombectomy for Acute Basilar Artery Occlusion in Early Therapeutic Time Window

Background: The natural history of basilar artery occlusion (BAO) is devastating, with morbidity rates increasing up to 80%. However, the efficacy of recanalization therapy for BAO has not been established as yet. Objective: We analyzed consecutive cases of BAO treated with mechanical thrombectomy (MT) to evaluate its safety and efficacy and to determine factors associated with the prognosis. Methods: Between October 2011 and September 2016, MT was performed in 34 patients with BAO. MT was performed using the Penumbra system and stent retriever. CT perfusion was used for evaluating patients. Cerebral blood flow (CBF) maps and cerebral blood volume (CBV) maps were evaluated. CBF/CBV mismatch was defined as ≥50% penumbra. Clinical outcomes were correlated with demographic, clinical, and radiographic findings. Results: The median baseline National Institutes of Health Stroke Scale score was 29 (14-33). The recanalization rate (≥thrombolysis in cerebral infarction grades 2b) was 100%. The median onset to recanalization time (OTR) was 197 (160-256) min. Favorable outcomes (modified Rankin Scale ≤2) at 90 days occurred in 56% (n = 19 of 34). The mortality rate at 90 days was 12% (n = 4 of 34). In univariate analysis, intravenous (IV) recombinant tissue-type plasminogen activator (rt-PA) use, and OTR were significantly associated with favorable outcomes. In a multivariate logistic regression model, IV rt-PA use and lower National Institute of Health Stroke Scale score were significantly related to favorable outcomes. Conclusion and Relevance: Multimodal endovascular therapy using the Penumbra system and stent retriever demonstrated a high recanalization rate and favorable outcomes for BAO. Both devices were feasible and effective in the treatment of BAO. An approach combining MT with IV thrombolysis provided a better recanalization rate and more favorable clinical outcomes.

Optimal thresholds for ischemic penumbra predicted by computed tomography perfusion in patients with acute ischemic stroke treated with mechanical thrombectomy

Background and purpose

Optimal thresholds for ischemic penumbra detected by CT perfusion (CTP) in patients with acute ischemic stroke (AIS) have not been elucidated. In this study we investigated optimal thresholds for salvageable ischemic penumbra and the risk of hemorrhagic transformation (HT).

Methods

A total of 156 consecutive patients with AIS treated with mechanical thrombectomy (MT) at our hospital were enrolled. Absolute (a) and relative (r) CTP parameters including cerebral blood flow (aCBF and rCBF), cerebral blood volume (aCBV and rCBV), and mean transit time (aMTT and rMTT) were evaluated for their value in detecting ischemic penumbra in each of seven arbitrary regions of interest defined by the major supplying blood vessel. Optimal thresholds were calculated by performing receiver operating characteristic curve analysis in 47 patients who achieved Thrombolysis In Cerebral Infarction (TICI) grade 3 recanalization. The risk of HT after MT was evaluated in 101 patients who achieved TICI grade 2b–3 recanalization.

Results

Absolute CTP parameters for distinguishing ischemic penumbra from ischemic core were as follows: aCBF, 27.8 mL/100 g/min (area under the curve 0.82); aCBV, 2.1 mL/100 g (0.75); and aMTT, 7.30 s (0.70). Relative CTP parameters were as follows: rCBF, 0.62 (0.81); rCBV, 0.83 (0.87); and rMTT, 1.61 (0.73). CBF was significantly lower in areas of HT than in areas of infarction (aCBF, p<0.01; rCBF, p<0.001).

Conclusions

CTP may be able to predict treatable ischemic penumbra and the risk of HT after MT in patients with AIS.

Pregnancies with factor V deficiency: a case report and review of the literature

CASE REPORT

A 30-year-old Japanese nulliparous woman visited for pregnancy at 33 weeks with a massive ovarian tumor located in the pouch of Douglas. By preoperative screening, her prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged, and her FV activity was significantly decreased to 4.8%. After prophylactic FFP 20 ml/kg was administered and her FV factor was 19.3%, cesarean delivery was performed, and her perioperative course was uneventful. One year later, she underwent a dilatation and evacuation because of a missed abortion, although prophylactic FFP was not administered. During a third pregnancy, after prophylactic FFP 20 ml/kg was administered and FV activity increased to 21.1%, elective cesarean delivery was performed, and her postoperative course was uneventful.

CONCLUSION

For surgical therapy or delivery, the goal of therapy is to maintain FV activity above 20%. It is particularly useful to administer prophylactic FFP.

Quantitative Analyses of Hepatic OATP-Mediated Interactions Between Statins and Inhibitors Using PBPK Modeling With a Parameter Optimization Method

This study aimed to construct a widely applicable method for quantitative analyses of drug-drug interactions (DDIs) caused by the inhibition of hepatic organic anion transporting polypeptides (OATPs) using physiologically based pharmacokinetic (PBPK) modeling. Models were constructed for pitavastatin, fluvastatin, and pravastatin as substrates and cyclosporin A (CsA) and rifampicin (RIF) as inhibitors, where enterohepatic circulations (EHC) of statins were incorporated. By fitting to clinical data, parameters that described absorption, hepatic elimination, and EHC processes were optimized, and the extent of these DDIs was explained satisfactorily. Similar in vivo inhibition constant (K_i ) values of each inhibitor against OATPs were obtained, regardless of the substrates. Estimated K_i values of CsA were comparable to reported in vitro values with the preincubation of CsA, while those of RIF were smaller than reported in vitro values (coincubation). In conclusion, this study proposes a method to optimize in vivo PBPK parameters in hepatic uptake transporter-mediated DDIs.

[A Case of Middle Cerebral Artery Stenosis Presented with Limb-Shaking TIA]

Involuntary movement is a rare clinical manifestation of transient ischemic attack (TIA). However, limb-shaking TIA is well described presentation of carotid occlusive disease. We present the case of a patient who developed limb-shaking TIA associated with high-grade stenosis of middle cerebral artery (M1), which was treated with percutaneous transluminal angioplasty (PTA). The procedure was performed successfully without complication and the symptom disappeared immediately after the procedure. The patient remained free of symptoms at the 38-month follow-up. There was no tendency of restenosis of M1. In this case, PTA was technically feasible and beneficial for limb-shaking TIA with M1 stenosis. Limb-shaking TIA can be a symptom of high-grade stenosis of M1.

Endovascular Stenting for Pseudoaneurysms of the Cervical Carotid Artery

The authors report two cases of pseudoaneurysm of the cervical carotid artery treated with endovascular stenting. One patient presented with cerebral ischemia due to traumatic carotid dissection and underwent stent placement 3 weeks after injury when the wide-necked pseudoaneurysm was seen to enlarge at the dissecting portion.

The aneurysm thrombosed while the carotid artery remained patent without ischemic complications for 2 years. The other patient developed repeated massive bleeding from an exposed pseudoaneurysm at the right carotid-subclavian junction resulting from radiotherapy for thyroid cancer with subsequent skin infection.

Since skin grafting failed and two attempts at coil embolization resulted in compaction with recurrent enlargement of the aneurysm, endovascular stenting was performed with endosaccular coil packing between the stent struts. Hemostasis was achieved for 2 months. Both cases illustrate successes of the stent in highly difficult situations.

Cost-effectiveness of a community-based screening programme for chronic atrial fibrillation in Japan

Objectives: To examine the cost-effectiveness of a community-based screening programme for chronic atrial fibrillation (AF) in Japan.

Methods: Using a computer model of a Markov process, the cost-effectiveness of an annual ECG screening programme and an annual pulse palpation screening programme for arrhythmia were compared with no screening. A hypothetical Japanese population of 65 year old individuals was followed until 85 years of age. We assumed that individuals with irregular beats on palpation were worked up by ECG and that ECG was perfect in detecting AF, whereas palpation was not. It was also assumed that patients diagnosed with AF received anticoagulant therapy, that some AF patients developed ischaemic stroke, and that some on anticoagulant therapy developed intracranial or gastrointestinal haemorrhage. Costs, efficacy of anticoagulation, utility of health status, and clinical variables were estimated from the literature. Outcomes were expressed as US dollars per quality-adjusted life-year (QALY).

Results: Both annual ECG screening programme and annual palpation screening programme were more costly and at the same time more effective compared with no screening, with their incremental cost-effectiveness ratios approximately US$8000 per QALY in males and US$10,000 per QALY in females. Sensitivity analyses showed high sensitivity of cost-effectiveness ratios to the incidence of ischaemic stroke and anticoagulants prescription rate. Two annual screening programmes were similar in effectiveness and costs.

Conclusion: To prevent ischaemic stroke associated with AF, both annual ECG screening and annual palpation screening were favourable in the context of conventional criteria for cost-effectiveness.