Although coil embolization is commonly perceived as a minimally invasive procedure, the associated radiation exposure cannot be disregarded. To date, no specific study has investigated radiation exposure during coil embolization. This study aimed to investigate the potential of lowering the pulse rate to decrease radiation exposure during coil embolization while maintaining patient safety. Radiation data and clinical features of 70 patients who underwent coil embolization between 2015 and 2020 were retrospectively analyzed. Since July 2017, the pulse rate was regulated from 7.5 to 4 frames per second (f/s). Statistical analyses were performed to examine the correlation between pulse rate and radiation exposure. Out of the 70 procedures, 30 were performed at the standard pulse rate (7.5 f/s), and 40 were performed at the lower pulse rate (4 f/s). In the lower-pulse-rate group, the absorbed dose to the patient (AK) was 2580.7 (±217) mGy, whereas in the standard-pulse-rate group, it was 4760 (±411.1). Both the dose-area product (DAP) and AK were substantially reduced in the low pulse rate group (p = 0.000002). There was a significant correlation between DAP and AK and pulse rate (p = 0.004, p = 0.0017, respectively). Moreover, there was no significant correlation between pulse rate and perioperative complications. Our findings suggest that using a lower pulse rate (4 f/s) can effectively reduce radiation exposure during coil embolization for cerebral aneurysms while ensuring patient safety.
Although microvascular decompression (MVD) is a reliable treatment for hemifacial spasm (HFS), postoperative delayed relief is one of its main issues. We previously evaluated the morphology of the lateral spread response (LSR) and reported correlation between delayed relief after MVD and polyphasic morphology of the LSR. This study aimed to investigate the morphology of LSR and the course of recovery of the compound motor action potential (CMAP), to better understand the pathophysiology of delayed healing of HFS. Based on the pattern of the initial LSR morphology on temporal and marginal mandibular branches stimulation, patients were divided into two groups: the monophasic and polyphasic groups. The results of MVD surgery and sequential changes in the CMAP were evaluated 1 week, 1 month, 1 year, and final follow-up after the surgery. Significantly higher rates of persistent postoperative HFS were observed in patients with the polyphasic type of initial LSR at 1 week and 1 month after the surgery (P < 0.05, respectively). In the polyphasic group, the amplitude of the CMAP tended to gradually improve with time, while in the monophasic group, the amplitude of the CMAP decreased on the seventh postoperative day, followed by its gradual improvement. There is a significant correlation between delayed relief after MVD and polyphasic morphology of the initial LSR in patients with HFS. In the polyphasic group, CMAP recovered earlier and showed less reduction in amplitude, suggesting segmental demyelination, with less damage to peripheral nerves.
This study aimed to determine the prevalence of lumbar ligamentum flavum lesions and identify correlations between radiological and pathological findings. We conducted an observational cross-sectional study of 349 patients (lumbar: n = 296, thoracic: n = 39, lumbar and thoracic: n = 14, mean age: 69 ± 12 years, male: 74%) who underwent posterior surgery for thoracolumbar spinal canal stenosis between January 2008 and April 2023 at our hospital.
Computed tomography (CT) revealed that the prevalence of ligamentum flavum lesions defined as a high-density area with a CT value of 200 Hounsfield Unit or higher in the lumbar and thoracic spine was 47% (147/310) and 85% (45/53), respectively. CT showed that most patients had radiologically suspected ossification in the lumbar (90%) and thoracic spine (98%) than radiologically suspected calcification. Lumbar lesions were thinner than the thoracic lesions (2.5 vs 3.7 mm, p < 0.01). Pathological examinations were performed in specimens collected from 34 cases (lumbar: n = 13, thoracic: n = 21), and ossification was found in 62% (8/13) and 95% (20/21) of lumbar and thoracic lesions (p = 0.02), respectively. Lastly, ossification was confirmed pathologically in 72% (8/11) and 95% (19/20) of lumbar and thoracic lesions that showed ossification on imaging (p = 0.13), respectively. The literature review revealed that the prevalence of the lumbar ligamentum flavum lesions varied from 1.5 to 35% and the patient population was mostly asymptomatic.
Collectively, we found that the prevalence of lumbar ligamentum flavum lesions in symptomatic patients was greater than previously reported. Histologically confirmed ossification was less common in lumbar lesions than in thoracic lesions.
Recent cohort studies on hemorrhagic and asymptomatic moyamoya disease have revealed that choroidal anastomosis, a type of fragile periventricular collateral pathway (periventricular anastomosis) typical of the disease, is an independent predictor of hemorrhagic stroke. However, treatment strategies for less-symptomatic nonhemorrhagic patients with choroidal anastomosis remain unclear. The Moyamoya Periventricular Choroidal Collateral (P-ChoC) Registry is an ongoing multicentered observational study that will test the hypothesis that extracranial-intracranial bypass prevents de novo hemorrhagic stroke in less symptomatic, nonhemorrhagic patients with choroidal anastomosis and may thus contribute to improving the prognosis of moyamoya disease. In this study, we report the study protocol of the moyamoya P-ChoC Registry and review the literature on choroidal anastomosis as a fragile collateral pathway.
Failure to retrieve a distal filter-based embolic protection device (EPD) is a potential complication of carotid artery stenting. This may be caused by trapping of the proximal marker of the EPD within the stent tip marker. Maintaining an adequate distance between the two can prevent this. We examined the behavior of several stent-filter-based EPD combinations, focusing on their propensity to become trapped or disengage in vitro. Four physicians subjectively rated the force required to result in trapping using a 5-point scale. Moreover, the force required to disengage trapped devices was evaluated. The Casper stent-Spider FX EPD combination was difficult to disengage when entrapment occurred, which suggested that this phenomenon tended to occur with this combination. The stent tip marker of the closed-cell stents advanced as they shortened, which may be a unique feature of closed-cell stents. Although trapping is uncommon, it can cause serious complications. To prevent these complications, device characteristics should be well understood before they are used in patients.