The ELAPSS score consists of 6 easily retrievable predictors and can help physicians in decision making on the need for and timing of follow-up imaging in patients with unruptured intracranial aneurysms.

IMPORTANCE Unruptured intracranial aneurysms not undergoing preventive endovascular or neurosurgical treatment are often monitored radiologically to detect aneurysm growth, which is associated with an increase in risk of rupture. However, the absolute risk of aneurysm rupture after detection of growth remains unclear.OBJECTIVE To determine the absolute risk of rupture of an aneurysm after detection of growth during follow-up and to develop a prediction model for rupture.DESIGN, SETTING, AND PARTICIPANTS Individual patient data were obtained from 15 international cohorts. Patients 18 years and older who had follow-up imaging for at least 1 untreated unruptured intracranial aneurysm with growth detected at follow-up imaging and with 1 day or longer of follow-up after growth were included. Fusiform or arteriovenous malformation-related aneurysms were excluded. Of the 5166 eligible patients who had follow-up imaging for intracranial aneurysms, 4827 were excluded because no aneurysm growth was detected, and 27 were excluded because they had less than 1 day follow-up after detection of growth.EXPOSURES All included aneurysms had growth, defined as 1 mm or greater increase in 1 direction at follow-up imaging. MAIN OUTCOMES AND MEASURESThe primary outcome was aneurysm rupture. The absolute risk of rupture was measured with the Kaplan-Meier estimate at 3 time points (6 months, 1 year, and 2 years) after initial growth. Cox proportional hazards regression was used to identify predictors of rupture after growth detection.RESULTS A total of 312 patients were included (223 [71%] were women; mean [SD] age, 61 [12] years) with 329 aneurysms with growth. During 864 aneurysm-years of follow-up, 25 (7.6%) of these aneurysms ruptured. The absolute risk of rupture after growth was 2.9% (95% CI, 0.9-4.9) at 6 months, 4.3% (95% CI, 1.9-6.7) at 1 year, and 6.0% (95% CI, 2.9-9.1) at 2 years. In multivariable analyses, predictors of rupture were size (7 mm or larger hazard ratio, 3.1; 95% CI, 1.4-7.2), shape (irregular hazard ratio, 2.9; 95% CI, 1.3-6.5), and site (middle cerebral artery hazard ratio, 3.6; 95% CI, 0.8-16.3; anterior cerebral artery, posterior communicating artery, or posterior circulation hazard ratio, 2.8; 95% CI, 0.6-13.0). In the triple-S (size, site, shape) prediction model, the 1-year risk of rupture ranged from 2.1% to 10.6%.CONCLUSION AND RELEVANCE Within 1 year after growth detection, rupture occurred in approximately 1 of 25 aneurysms. The triple-S risk prediction model can be used to estimate absolute risk of rupture for the initial period after detection of growth.

Repeated PET scanning revealed improvements in CBF, perfusion pressure, and oxygen metabolism after CAS. In particular, the vascular reserve tended to improve gradually, while CBF, cerebral perfusion pressure, and CMRO2 increased rapidly and peaked soon after CAS. These results suggest that a large discrepancy between rapidly increased CBF, perfusion pressure, and a small increase in vascular reserve in the acute stage after CAS could cause hyperperfusion syndrome.

Surgical treatment is a viable alternative for patients 70 years of age or less with UCAs less than 10 mm in size or UCAs located in the anterior cerebral artery or middle cerebral artery, because the surgical risk of treating such UCAs is sufficiently lower than the annual rupture rate of UCAs (2.3%) and the mental stress suffered by patients with untreated UCAs.

Neurovascular interventional radiology (neuro-IR) procedures tend to require an extended fluoroscopic exposure time and repeated digital subtraction angiography. To evaluate the actual measurement of eye lens dose using a direct eye dosemeter in neuro-IR physicians is important. Direct dosimetry using the DOSIRIS™ (IRSN, France) [3 mm dose equivalent, Hp(3)] was performed on 86 cases. Additionally, a neck personal dosemeter (glass badge) [0.07 mm dose equivalent, Hp(0.07)] was worn outside the protective apron to the left of the neck. The average doses per case of neuro-IR physicians were 0.04 mSv/case and 0.02 mSv/case, outside and inside the radiation protection glasses, respectively. The protective effect of radiation protection glasses was approximately 60%. The physician eye lens dose tended to be overestimated by the neck glass badge measurements. A correct evaluation of the lens dose [Hp(3)] using an eye dosemeter such as DOSIRIS™ is needed for neuro-IR physicians.

We report a rare case of non-Hodgkin lymphoma with mass lesions of skull vault and ileocecum. The patient was an 82-year-old Japanese woman who exhibited a painless subcutaneous scalp tumor in the right parietal region associated with no neurological abnormalities. Magnetic resonance imaging of the head demonstrated a mass in the skull vault with iso- to hypointense signals on both T1- and T2-weighted imaging. Biopsy of the mass revealed that the tumor comprised large cells that were immunoreactive for CD20 (L-26) and CD79a. Diffuse large B-cell lymphoma (DLBCL) was therefore diagnosed. Further investigation could not identify any other evidence of systemic lymphoma other than ileocecal lesions. She was treated by irradiation (45 Gy) of the mass on the parietal bone and with rituximab, pirarubicin, cyclophosphamide, and vincristine. The patient achieved complete remission after 3 cycles of systemic chemotherapy. As of 30 months after presentation, no signs of lymphoma have been found.

The concept of optimum closure line was applied to a series of 51 consecutive middle cerebral artery aneurysms (14 ruptured, 37 unruptured) in 41 patients, 16 men and 25 women aged 29-79 years (mean 59.1 years). Visual inspection through the operating microscope revealed 3 types of aneurysm based on the origin of the aneurysm: bifurcation type (n ＝ 39), trunk type (n ＝ 9), and combined type (n ＝ 3). Clipping along the optimum closure line should restore the vascular structure to the original configuration. Combination clip techniques were useful to form a curved closure line. This technique requires adequate operative fields with dissection of the aneurysm and related arteries from the neighboring structures as far as possible. The closure line concept is helpful to decide how to apply clips for particular aneurysms to avoid risks of ischemic complication and future recurrence. Combination clip techniques are often necessary to match a curved closure line.

Blood blister-like aneurysms are dangerous aneurysms with fragile walls arising from the supraclinoid internal carotid artery (ICA). Primary treatment of these aneurysms in the acute stage is challenging, due to the substantial risk of periprocedural bleeding. We describe a series of 4 patients who presented with ruptured blister-like aneurysm of the ICA and were treated with completion of extracranial-intracranial high-flow bypass followed by inspection and trapping of the aneurysm. All patients were treated in the acute stage, within 48 hours of bleeding. External carotid artery to proximal middle cerebral artery bypass with interposed radial artery (RA) graft was established followed by approach to the lesion and trapping of the parent vessels. The aneurysms in 3 patients ruptured during dissection of the lesion from the surrounding structures, but bleeding was easily controlled. RA grafts were patent in all patients and no postoperative symptomatic ischemic or hemorrhagic complications were encountered, resulting in excellent outcomes with modified Rankin scale scores of 0 at follow up after 3 months. Our present strategy for surgical treatment of blister-like aneurysms completely avoided the risk of devastating intraoperative hemorrhage, offering a most cautious strategy associated with minimal risk of intraoperative massive bleeding.Key words: blister-like aneurysm, internal carotid artery, trapping, subarachnoid hemorrhage, external carotid artery to proximal middle cerebral artery bypass with interposed radial artery graft