In vitro comparison of middle meningeal artery embolization with Squid liquid embolic agent and Contour polyvinyl alcohol particles

Repeat Prostatic Artery Embolization with the Addition of a Liquid Embolic Agent: Short-term Results

RATIONALE AND OBJECTIVES

The long-term effectiveness of prostatic artery embolization (PAE) can be hampered by the recanalization of the previously embolized prostatic arteries (PA). The use of a liquid embolic agent (LEA) could limit this risk. The purpose of this study was to assess the safety and efficacy of repeat PAE (rePAE) using a LEA (Squid Peri) coupled with microspheres in patients experiencing recurring symptoms after initial embolization.

MATERIALS AND METHODS

This retrospective single-center study included all consecutive patients who underwent rePAE using Squid Peri coupled with microspheres. Angiographic patterns of prostatic revascularization were identified. Outcomes were assessed at the 3-month follow-up using the International Prostate Symptom Score (IPSS) and the Quality of Life (QoL) score. The primary endpoint was clinical success defined as an IPSS < 18 with > 25% decrease and a QoL score ≤ 3 with ≥ 1 point decrease. Safety was assessed by using the modified Clavien-Dindo classification.

RESULTS

30 consecutive men (mean age: 67.1 ± 9.5 years) were included. Recanalization of the previously embolized PA was found in 83.3% of patients. Technical success was 93.3%. Median follow-up was 4.9 months [IQR: 3.9 - 9.8]. Clinical success rate was 76.7%, with a mean decrease in IPSS of -9.3 ± 7.3 (p < 0.001) and a median decrease in QoL of -2 [IQR: - 4 - - 1] (p < 0.001). One patient presented with an acute urinary retention requiring readmission (grade IIIa complication).

CONCLUSION

Repeat PAE using Squid Peri coupled with microspheres is safe and effective for patients with recurring symptoms after initial embolization.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied.

METHODS

A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale.

RESULTS

Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001).

CONCLUSION

MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

Middle Meningeal Artery Embolization for Management of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a prevalent medical condition with potentially severe consequences if left untreated. While surgical removal has traditionally been the standard approach for treatment, middle meningeal artery (MMA) embolization has emerged as a promising minimally invasive alternative to reduce recurrences. This comprehensive review provides the general radiology community with an overview of MMA embolization as a therapeutic option for managing CSDH. The authors base their insights on existing evidence and their institutional experience. This overview encompasses the pathophysiology of CSDH as well as the potential advantages and limitations, safety profile, and potential complications of MMA embolization as compared with surgical treatment. The imaging findings seen before and after MMA, as well as insights into the procedural techniques used at the authors' institution, are described. On the basis of reports in the current literature, MMA embolization appears to be a safe and effective therapeutic option for managing CSDH, especially in patients who are unsuitable for surgery or at risk for recurrence. Nonetheless, further research is needed to validate these findings. Results from ongoing clinical trials hold promise for future validation and the establishment of scientific evidence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chatterjee in this issue.

Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization

BACKGROUND

Liquid embolic agents (LEAs) such as ethylene vinyl alcohol (EVOH) are utilized for middle meningeal artery embolization (MMAE) for chronic subdural hematomas (cSDH). LEAs may be advantageous for MMAE as they are permanent and can penetrate the microvasculature of the subdural membranes. LEA surface area (SA) can quantify this penetration. The segmentation of LEA SA is not described in the literature and may be of interest in refining MMAE technique.

METHODS

We retrospectively collected computerized tomography (CT) scans from 74 patients (with 95 cSDH) who underwent first-line MMAE with EVOH. Non-contrast head CTs were acquired pre-embolization, immediately post-embolization and at 1-, 3-, and 6 month follow-up. A 3D-Slicer was used to segment hematoma volumes and the liquid embolic cast. We hypothesized that greater LEA SA would be correlated with greater improvements in cSDH volumetric resolution.

RESULTS

There was significant resolution in cSDH volumes over the follow-up period compared to preoperative volume (p<0.0001). The LEA SA was significantly correlated with the rate of cSDH resolution at 3 months (R2=0.08, p=0.03), and 6 months (R2=0.14, p=0.01).

CONCLUSIONS

The correlation of LEA surface area with hematoma resolution at 3-months and 6-months suggests greater LEA penetration may improve radiographic outcomes. This study uniquely provides a quantitative radiological perspective on the effect of LEA penetration on cSDH resolution.

Lidocaine for headache prevention during chronic subdural hematoma embolization

BACKGROUND

Middle meningeal artery embolization (MMAE) for the management of chronic subdural hematomas (CSDH) with ethylene vinyl alcohol (EVOH) causes an evident patient discomfort due to meningeal nociceptors stimulation. The aim of this study was to assess safety and efficacy of intra-arterial lidocaine (IAL) before MMAE of CSDH with EVOH.

METHODS

We analyzed all consecutive patients with bilateral CSDH undergoing MMAE with EVOH. We used a monolateral IAL injection, with casual allocation. We assessed the headache felt by patients during embolization with the visual analog scale (VAS) and compared scores obtained after embolization of both sides. We followed the STROBE guidelines for case-control studies. Paired t-test and χ2 test were used to compare the distribution of variables in IAL vs control group.

RESULTS

Between September 2021 and March 2023, 32 patients underwent bilateral MMAE with EVOH for a CSDH. Lidocaine treatment resulted in a substantially lower VAS score compared to the control group (median 3 vs 7, p < 0.001), with no substantial side effect. Compliance also benefited from lidocaine administration.

CONCLUSIONS

In patients with CSDH undergoing MMAE, IAL seems to reduce pain sensation associated with EVOH injection and to increase patients' compliance during treatment.