Simultaneous resolution of arachnoid cyst and chronic subdural hematoma after middle meningeal artery embolization: illustrative case.

BACKGROUND: Arachnoid cysts are cerebrospinal fluid-filled spaces that are typically congenital and treated conservatively or with fenestration when symptomatic. Chronic subdural hematomas (cSDHs) can arise in the presence of arachnoid cysts due to fragile leptomeningeal vessels or veins within the cyst wall or cyst lumen, leading to bleeding and subsequent hematoma formation. Middle meningeal artery (MMA) embolization is regularly used for the treatment of cSDH as an alternative to craniotomy and evacuation. OBSERVATIONS: Here, the authors present the first known report of the simultaneous resolution of an arachnoid cyst and cSDH following MMA embolization in an adult. A 24-year-old male presented to the emergency department with 1 month of worsening headaches. Imaging revealed the presence of a cSDH and ipsilateral arachnoid cyst. The cSDH was treated with MMA embolization using coils exclusively. Follow-up imaging 4 months after embolization demonstrated simultaneous resolution of both the hematoma and the arachnoid cyst. LESSONS: MMA embolization has been used for the treatment of cSDH. In cases in which the hematoma is related to an arachnoid cyst, MMA embolization can also lead to the concurrent resolution of both pathologies. https://thejns.org/doi/10.3171/CASE24192.

Optimizing suction force in mechanical thrombectomy: Priming the aspiration tubing with air versus saline.

Objective: We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities. Methods: Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities. Results: Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01). Conclusions: Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

Reducing frame rate and pulse rate for routine diagnostic cerebral angiography: ALARA principles in practice.

OBJECTIVE: Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality. METHODS: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality. RESULTS: A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time. CONCLUSIONS: We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.

ALARA principles in practice: reduced frame and pulse rates for middle meningeal artery embolization.

Objective: As the prevalence of neuroendovascular interventions increases, it is critical to mitigate unnecessary radiation for patients, providers, and health care staff. Our group previously demonstrated reduced radiation dose and exposure during diagnostic angiography by reducing the default pulse and frame rates. We applied the same technique for basic neuroendovascular interventions. Methods: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. We studied consecutive, unilateral middle meningeal artery embolizations treated with particles. Total radiation dose, radiation per angiographic run, total radiation exposure, and exposure per run were calculated. Multivariable log-linear regression was performed to account for patient body mass index (BMI), number of angiographic runs, and number of vessels catheterized. Results: A total of 20 consecutive, unilateral middle meningeal artery embolizations were retrospectively analyzed. The radiation reduction protocol was associated with a 39.2% decrease in the total radiation dose and a 37.1% decrease in radiation dose per run. The protocol was associated with a 41.6% decrease in the total radiation exposure and a 39.5% decrease in exposure per run. Conclusions: Radiation reduction protocols can be readily applied to neuroendovascular interventions without increasing overall fluoroscopy time and reduce radiation dose and exposure by 39.2% and 41.6% respectively. We strongly encourage all interventionalists to be cognizant of pulse rate and frame rate when performing routine interventions.

Enlarging symptomatic arachnoid cyst in an elderly patient: illustrative case.

BACKGROUND: Arachnoid cysts are congenital or acquired structures found within the brain and are rarely symptomatic for adults. The literature documenting enlarging arachnoid cysts in adults is also discussed. OBSERVATIONS: An elderly woman presented with acutely worsening headaches, photophobia, cognitive function, and a seizure-like episode. The patient had a known arachnoid cyst with a decade of radiographic stability, which was now idiopathically enlarging. The patient had a previous history of traumatic brain injuries but no reported trauma around the time of presentation. Due to the severity of midline shift and symptomatology, the decision was made to treat the patient surgically with fenestration and shunting. She recovered well postoperatively. LESSONS: During the workup for a symptomatic elderly patient, enlargement of a previously asymptomatic arachnoid cyst should remain on the differential until specifically ruled out, even in the absence of recent trauma. While rare, enlarging arachnoid cysts result in neurological findings and impact the quality of life for patients.