Investigation of Fluoroscopy Time and Radiation Dose by the Number of Cerebral Angiography Operator Experiences.

Objective: We investigated the fluoroscopy time (FT) and radiation dose by the number of cerebral angiography (CA) operator experiences to clarify the learning curve of CA. Methods: The subjects were cases for whom CA was performed at our hospital for 5 years between April 2015 and March 2020. Based on the number of CA operator experiences, they were classified into four groups: 1-50 cases (group A), 51-100 cases (group B), 101-200 cases (group C), and 201 cases and later (group D). The FT and radiation dose were retrospectively investigated. Results: Of the 865 consecutive CA cases, 293 cases for follow-up, i.e. after treatment, 54 for arteriovenous shunt diseases, 21 lacking data, and 1 case requiring intervention for thrombosis during CA were excluded. In total, 496 CA cases were investigated. There were 61 cases in group A, 56 cases in group B, 44 cases in group C, and 335 cases in group D, and there was no significant difference in patient background factors among the groups. The median FT and radiation dose (interquartile range) in each group were 20.2 min (14.6) and 374 mGy (185.3) in group A, 14.8 min (12.1) and 366 mGy (167.9) in group B, 10.8 min (6) and 320 mGy (151.7) in group C, and 9.4 min (6.4) and 336 mGy (171) in group D. The FT was significantly shorter in group C than in group A, and significantly shorter in group D than in groups A, B, and C. The radiation dose was significantly lower in groups C and D than in groups A and B. Conclusion: This study suggested that CA can be performed alone after experiencing approximately 100 cases as an operator.

Comparison of Treatment Results by Coil Embolization Procedures for Ruptured Cerebral Aneurysms.

Objective: In coil embolization of ruptured cerebral aneurysms, intraoperative cerebral aneurysm re-rupture and thromboembolism are of concern. A good embolic condition can be expected by adjunctive techniques, but there is an increased risk of complications. We investigated the treatment results by coil embolization procedures for ruptured cerebral aneurysms. Methods: Between January 2016 and December 2019, 75 ruptured saccular cerebral aneurysms were treated by coil embolization at our hospital. The background factors, results of aneurysm embolization, intraoperative re-rupture, symptomatic cerebral embolism, and other factors were investigated retrospectively. We compared and examined these factors based on the procedure. Results: The mean age was 62.8 and there were 57 female patients (76.0%). The single catheter technique (SCT) was used in 44 cases (58.7%) and the adjunctive technique was used in 31 cases (41.3%). Complete obliteration (CO) was achieved in 24 cases (32.0%), there was a neck remnant (NR) in 23 (30.7%), body filling (BF) was observed in 28 (37.3%), intraoperative re-rupture occurred in 7 (9.3%), and symptomatic cerebral embolism developed in 6 (8.0%), but no postoperative re-rupture was observed. Retreatment was required in only three cases of SCT. On comparison by procedure, the incidence of symptomatic cerebral embolism was significantly lower in SCT group than in the adjunctive technique group (2.3% vs 16.1%, p = 0.04). Conclusion: Among the cases of coil embolization for ruptured cerebral aneurysms at our hospital, SCT resulted in a lower incidence of symptomatic cerebral embolism than adjunctive techniques. It is essential to select an appropriate procedure in each case by understanding the characteristics of each procedure.

The Usefulness of Prasugrel as Rescue Medication in Neuroendovascular Therapy.

Objective: In neuroendovascular therapy, clopidogrel resistance and thrombosis are common problems. In such cases, we use prasugrel as rescue medication, and we clarified its usefulness. Methods: We retrospectively investigated 199 consecutive cases of neuroendovascular therapy performed at our hospital from April 2016 to March 2018, and examined the safety and effectiveness of prasugrel. Results: There were 14 cases of prasugrel administration: six cases of coil embolization for cerebral aneurysm, five cases of carotid artery stenting (CAS), and three other cases.The reasons for prasugrel administration were as follows: emergency stent use in four cases, intraoperative thrombosis in three cases, intra-stent thrombosis after CAS in three cases, and others in four cases. In all cases, it was used in combination with aspirin and the median duration of administration was 212 days. Regarding its safety, there was one hemorrhagic complication at the puncture site for which the involvement of prasugrel was unable to be excluded, but it was improved by conservative treatment and there was no major hemorrhage such as intracranial hemorrhage. Regarding its efficacy, in one case, the thrombus during coil embolization did not completely disappear after prasugrel administration and additional mechanical thrombolysis was required. However, no new thrombosis was observed during prasugrel administration in all 14 cases. Conclusion: Prasugrel may be useful as a rescue medication in neuroendovascular therapy.

[Are Localized Lesions in the Common Carotid Artery a Risk Factor for Recurrence of Ischemic Stroke in Patients with Symptomatic Carotid Artery Stenosis?]

BACKGROUND AND PURPOSE: Various studies have addressed risk factors for recurrence of ischemic stroke in patients with symptomatic carotid artery stenosis. However, no investigations have compared common localized carotid artery lesions and internal carotid artery lesions, including carotid bifurcation. This retrospective study investigated risk factors for ischemic stroke recurrence in patients with symptomatic carotid artery stenosis, including a comparison of lesion sites. METHODS: Of 61 consecutive patients admitted to the authors' hospital due to a diagnosis of symptomatic carotid artery stenosis between April 2015 and March 2018, data from 59 were retrospectively reviewed(2 patients diagnosed with arterial dissection were excluded). The primary end point was recurrence of ischemic stroke caused by symptomatic carotid artery stenosis, the cause of the first event. Patients were censored at the time of surgical intervention;events occurring during and after surgical intervention were not included. In the ischemic stroke recurrence and non-recurrence groups, each item was analyzed using the Kaplan-Meier method, and a log-rank test was performed with a significance level set to 5%. RESULTS: Ischemic stroke recurrence before surgical intervention was observed in 5(8.5%)patients. In comparing the recurrence and non-recurrence groups, a significant difference was observed in age(p=0.027)and lesion site(p <0.001). CONCLUSION: A localized lesion in the carotid artery was a risk factor for recurrence of ischemic stroke in patients with symptomatic carotid artery stenosis. For individuals with symptomatic localized lesions in the common carotid artery, surgical intervention should be considered-in addition to medical treatment-regardless of the degree of stenosis.

Innate sexuality determines the mechanisms of telomere maintenance.

Recently, telomere length has been shown to be differentially regulated in asexually and sexually reproducing planarians. In addition, it was found that asexual worms maintain telomere length somatically during reproduction by fission or when regeneration is induced by amputation, whereas sexual worms only achieve telomere elongation through sexual reproduction. We have established an experimental bioassay system to induce switching from asexual to sexual reproduction in planarians, that is, sexualization. In this study, the relationship between the reproductive mode and telomere maintenance was investigated using innate asexually reproducing worms, innate sexually reproducing worms, and experimentally sexualized worms. Here, we show that innate asexual planarians maintain telomere length during cell division and that innate sexual planarians exhibit telomere shortening. However, experimental sexualized worms maintain telomere length during cell division. These results indicate that innate sexuality is linked to the mechanism of telomere maintenance.

The Dugesia ryukyuensis database as a molecular resource for studying switching of the reproductive system.

The planarian Dugesia ryukyuensis reproduces both asexually and sexually, and can switch from one mode of reproduction to the other. We recently developed a method for experimentally switching reproduction of the planarian from the asexual to the sexual mode. We constructed a cDNA library from sexualized D. ryukyuensis and sequenced and analyzed 8,988 expressed sequence tags (ESTs). The ESTs were analyzed and grouped into 3,077 non-redundant sequences, leaving 1,929 singletons that formed the basis of unigene sets. Fifty-six percent of the cDNAs analyzed shared similarity (E-value<1E -20) with sequences deposited in NCBI. Highly redundant sequences encoded granulin and actin, which are expressed in the whole body, and other redundant sequences encoded a Vasa-like protein, which is known to be a component of germ-line cells and is expressed in the ovary, and Y-protein, which is expressed in the testis. The sexualized planarian expressed sequence tag database (http://planaria.bio.keio.ac.jp/planaria/) is an open-access, online resource providing access to sequence, classification, clustering, and annotation data. This database should constitute a powerful tool for analyzing sexualization in planarians.