Hemorrhage risk of cerebral dural arteriovenous fistulas following Gamma Knife radiosurgery in a multicenter international consortium

Reconstructive treatment using stent placement for type IIa+b lateral sinus dural arteriovenous fistulas complicated with sinus occlusion

BACKGROUND

Cognard type IIa+b dural arteriovenous fistulas (DAVFs) in the lateral sinuses are often complicated with venous sinus obstruction and accompanied by clinical symptoms and a risk of hemorrhage. The purpose of this study was to assess venous sinus stenting as a viable alternative treatment in complex lateral sinus DAVFs and examine its efficacy and safety.

METHODS

We retrospectively examined patients diagnosed with type IIa+b DAVF in the transverse or sigmoid sinus with associated venous sinus occlusion who were treated via stent placement between April 2017 and June 2019.

RESULTS

Six patients were included in this study. Three patients had DAVFs in both the transverse and sigmoid sinuses, two in the transverse sinus and confluence of sinuses, and one in the transverse sinus. The most common symptoms were headache, dizziness, and limb weakness. At the last follow-up, three patients had significant improvement, and three were asymptomatic. Angiograms performed immediately after the surgery showed restoration of the anterograde venous drainage in all patients. According to the follow-up angiography results, two DAVFs were completely obliterated, and four remained as stable type I DAVFs. Most patients had satisfactory venous sinus drainage, except one who had in-stent stenosis.

CONCLUSIONS

Stent placement can restore sinus patency, improve clinical symptoms, and decrease intracranial hemorrhage risk. This approach may be an effective option for treating type IIa+b lateral DAVFs complicated by sinus occlusion.

Sinovenous outflow in lateral sinus dural arteriovenous fistulas after stereotactic radiosurgery: a retrospective longitudinal imaging study

PURPOSE

To investigate sinovenous outflow restriction (SOR) in lateral sinus dural arteriovenous fistulas (LSDAVFs) after Gamma Knife radiosurgery (GKRS) and its association with complete obliteration.

METHODS

We retrospectively (1995-2019) enrolled 39 patients with LSDAVFs who had undergone GKRS alone and evaluated their angiography and magnetic resonance imaging (MRI) before and after GKRS. The LS conduits ipsilateral and contralateral to the DAVFs were scored using a 5-point scoring system, with scores ranging from 0 (total occlusion) to 4 (fully patent). SOR was defined by a conduit score < 2. Demographics, imaging features, and outcomes were compared between patients with and without ipsilateral SOR after GKRS. Logistic regression analysis was performed to estimate the odds ratio (OR) for obliteration with the imaging findings.

RESULTS

After a median angiographic follow-up of 28 months for the 39 patients, the ipsilateral LS became more restrictive (median conduit score before and after GKRS: 2 vs. 1, p = .011). Twenty-one patients with ipsilateral SOR after GKRS had a significantly lower obliteration rate (52.4% vs. 94.4%, p = .005) than those without SOR. Follow-up SOR was independently associated with a lower obliteration rate (OR 0.05, p = .017) after adjustment for age, cortical venous reflux, and absent sinus flow void on MRI.

CONCLUSION

This study demonstrates a restrictive change of outflow in LSDAVFs after GKRS and a lower obliteration rate in patients with SOR. Follow-up imaging for SOR may help predict outcomes of these patients.

Effect of Holistic Nursing Intervention Combined with Humanized Nursing Intervention on Activities of Daily Living and Limb Movement Ability of Elderly Patients with Cerebral Hemorrhage after Surgery

Background

To improve the nursing status, activities of daily living (ADL), and limb movement ability of elderly patients with cerebral hemorrhage and to actively explore the comprehensive nursing mode that can meet the rehabilitation needs of patients.

Methods

128 elderly patients with cerebral hemorrhage admitted to our department (2019.01–2021.01) were included in the study and randomly divided into the reference group and the study group according to the numeration table, with 64 cases in each group. The reference group received routine nursing, while the study group received holistic nursing combined with humanized nursing. Statistical methods were used to analyze the nursing effect of the two intervention models.

Results

With better scores of the upper limb muscle strength, lower limb muscle strength, and total Fugl-Meyer Assessment (FMA) in both groups after nursing, the scores in the study group after nursing were higher than those in the reference group (P < 0.05). After nursing, the ADL scores of both groups were significantly improved and the score in the study group was better than that in the reference group (P < 0.05). After nursing, the degree of neurological deficit in both groups was significantly better than that before nursing and the degree in the reference group was more serious than that in the study group (P < 0.05). Compared with the reference group, the total infection rate in the study group was lower, while the nursing satisfaction was higher, with statistical significance (P < 0.05).

Conclusion

The holistic nursing combined with humanized nursing has a remarkable effect on the postoperative intervention of elderly patients with cerebral hemorrhage. It can improve the limb movement function, enhance the ADL, reduce the degree of neurological deficit, improve the quality of life, and enhance the nursing satisfaction of patients after intervention, which is worthy of clinical popularization.

Maintenance of Tight Junction Integrity in the Absence of Vascular Dilation in the Brain of Mice Exposed to Ultra-High-Dose-Rate FLASH Irradiation

Persistent vasculature abnormalities contribute to an altered CNS microenvironment that further compromises the integrity of the blood-brain barrier and exposes the brain to a host of neurotoxic conditions. Standard radiation therapy at conventional (CONV) dose rate elicits short-term damage to the blood-brain barrier by disrupting supportive cells, vasculature volume and tight junction proteins. While current clinical applications of cranial radiotherapy use dose fractionation to reduce normal tissue damage, these treatments still cause significant complications. While dose escalation enhances treatment of radiation-resistant tumors, methods to subvert normal tissue damage are clearly needed. In this regard, we have recently developed a new modality of irradiation based on the use of ultra-high-dose-rate FLASH that does not induce the classical pathogenic patterns caused by CONV irradiation. In previous work, we optimized the physical parameters required to minimize normal brain toxicity (i.e., FLASH, instantaneous intra-pulse dose rate, 6.9 · 106 Gy/s, at a mean dose rate of 2,500 Gy/s), which we then used in the current study to determine the effect of FLASH on the integrity of the vasculature and the blood-brain barrier. Both early (24 h, one week) and late (one month) timepoints postirradiation were investigated using C57Bl/6J female mice exposed to whole-brain irradiation delivered in single doses of 25 Gy and 10 Gy, respectively, using CONV (0.09 Gy/s) or FLASH (>106 Gy/s). While the majority of changes found one day postirradiation were minimal, FLASH was found to reduce levels of apoptosis in the neurogenic regions of the brain at this time. At one week and one month postirradiation, CONV was found to induce vascular dilation, a well described sign of vascular alteration, while FLASH minimized these effects. These results were positively correlated with and temporally coincident to changes in the immunostaining of the vasodilator eNOS colocalized to the vasculature, suggestive of possible dysregulation in blood flow at these latter times. Overall expression of the tight junction proteins, occludin and claudin-5, which was significantly reduced after CONV irradiation, remained unchanged in the FLASH-irradiated brains at one and four weeks postirradiation. Our data further confirm that, compared to isodoses of CONV irradiation known to elicit detrimental effects, FLASH does not damage the normal vasculature. These data now provide the first evidence that FLASH preserves microvasculature integrity in the brain, which may prove beneficial to cognition while allowing for better tumor control in the clinic.

Complication rate, cure rate, and long-term outcomes of microsurgery for intracranial dural arteriovenous fistulae: a multicenter series and systematic review

Although microsurgery is an established treatment modality for intracranial dural arteriovenous fistula (dAVF), data regarding the perioperative complication rate, cure rate, and long-term outcomes remain scarce. The aims of this study were to describe our original experience with microsurgery, including the surgical complications and pitfalls, and conduct a systematic review of the relevant literature. A multicenter cohort of patients with dAVF treated by microsurgery was retrospectively assessed. In addition, the PubMed database was searched for published studies involving microsurgery for dAVF, and the complication rate, cure rate, and long-term outcomes were estimated. The total number of patients in our multicenter series and published articles was 553 (593 surgeries). The overall rates of transient complications, permanent complications, death, and incomplete treatment were 11.4, 4.0, 1.2, and 6.5%, respectively. A favorable outcome was achieved for 90.1% patients, even though almost half of the patients presented with intracranial hemorrhage. Of note, the incidence of recurrence was only one per 8241 patient-months of postoperative follow-up. Surgeries for anterior cranial fossa dAVF were associated with a lower complication rate, whereas those for tentorial dAVF were associated with higher complication and incomplete treatment rates. The complication and incomplete treatment rates were lower with simple disconnection of cortical venous drainage than with radical occlusion/resection of dural shunts. Our findings suggest that the cure rate, complication rates, and outcomes of microsurgery for dAVF are acceptable; thus, it could be a feasible second-line treatment option for dAVF. However, surgeons should be aware of the specific adverse events of microsurgery.