Improving the outcome of chronic subdural hematoma by embolization of the middle meningeal artery (ELIMINATE).

Chronic subdural hematoma (cSDH) is a relatively frequent occuring disease in
neurosurgical practice. cSDH usually develops after minor head trauma and is
most common in the elderly. The majority of cSDH patients (80%) need to undergo
surgery in order to relieve symptoms. There are different surgical methods, but
90% of the time burr-hole craniostomy (BHC) is used. One or two holes on the
affected side of the skull are drilled and the hematoma is drained. This
immediately relieves patients of their (life-threatening) symptoms. However,
surgery is costly, and in these often frail patients, with multi-morbidity,
comes with significant risks for future cognitive functioning, and therefore
loss of independence. Furthermore, recurrence rates after surgery range from
about 10-30%, resulting in even more operations.Therefore, the optimal
treatment for cSDH remains a *burning clinical question* for which neurologists
and neurosurgeons do not have evidence-based answers.

In order to come up with a solution, multiple different therapies have been
proposed. Embolization of the middle meningeal artery is by far the most
striking one.The goal of embolization is to devascularize the subdural
membranes to a sufficient extent such that the balance is shifted from the
continued leakage and accumulation of blood products towards reabsorption,
hereby reducing postoperative recurrence and ultimately morbidity and
mortality. The usage of embolization in cSDH patients was introduced in 2000.
and since then there have been multiple case reports, case series and cohort
studies that have investigated its safety and effectiveness. The findings of
these studies studies were summarized in recent systematic reviews about
embolization which highlight its potential in the management of cSDH patients.
Apart from the lower recurrence (2.0 - 5.0% in all cases) and complication rate
(0 - 2.1% in all cases), also additional benefits such as the minimally
invasive character of the procedure are exciting. Nevertheless it is stressed
that these results are based on studies with moderate quality and a small
sample size.

Without studying the efficiacy and safety of embolization in larger scaled
randomized trials, the question if the addition of embolization really improves
recurrence rates, functional outcome and complication rate, will remain
unanswered. By elucidating these topics the treatment of cSDH patients can be
improved significantly.

Primary: To evaluate whether additional embolization of the middle meningeal
artery after surgery for cSDH reduces the recurrent surgery rate. Secondary: to
evaluate whether the use of middle meningeal artery embolization after surgical
treatment in symptomatic cSDH patients increases quality of life (SF-36 and the
EQ-5D-5L), performance in activities of daily living (Barthel Index),
functional outcome (mRS), cognitive functioning (MOCA/m-TICS) and reduces
mortality, occurrence of complications, recurrence rate, size and volume of the
hematoma, neurological impairment (mNIHSS and Markwalder score) and the use of
care and health-related costs (iMCQ and iPCQ).

Multicentre, randomized controlled open-label superiority trial.

Peri-operative embolization until 72 hours after surgery.

Symptomatic cSDH patients will undergo peri-operative embolization of the
middle meningeal artery until 72 hours after surgical treatment. Complications
are monitored during hospital admission and follow-up. Radiological and
clinical follow-up is at eight, 16 and 24 weeks post-intervention with a
CT-scan of the head and assessment of mRS, MOCA/m-TICS, mNIHSS, Markwalder
score, SF-36, EQ-5D-5L, Barthel Index, iMCQ and iPCQ. Standard care after
surgery entails outpatient follow-up with on average two CT-scans, indicated by
clinical signs and symptoms. For this study a CT-scan will be performed
routinely at eight, 16 and 24 weeks post-intervention; embolization, on average
one CT-scan, and questionnaires are extra for this study. Potential
complications of endovascular embolization are thromboembolic events which
occur in <0.3%. Patients may benefit from the study if embolization proves to
be effective to prevent recurrent surgery, thereby lowering the morbidity and
mortality rate and increasing quality of life.