MMA Embolization - Chronic subdural hematoma - Ep.1/2

Middle Meningeal Artery (MMA) Embolization for Chronic Subdural Hematoma (CSDH) 

Episode 1

Now, You don`t need to go through multiple textbooks or Scientific journals. As usual, every SLICE Episode is exceptional in terms of sharing worlds` experts experience with the latest updates. This time SLICE platform has provided all what you need to know about The MMA Embolization in about 2 informative hours only over 2 Episodes. 

First Kick was outstanding. Exclusively releasing the results OTEMACS Trial. Don`t know much about it?! …. Rapid overview!

It is a randomized controlled multicenter study over multiple centers in France including about 440 Patient. It compared the MMA with Onyx vs MMA (1-5 Dyas post-surgical) + Standard Surgery (Classic craniotomy ... Burr holes). 

Looks like Interesting Results?! Game is Over?!

Regarding efficacy, recurrence rate after embolization was 5.3% while was 19.79% for surgery over three months duration. Moreover. Residual hematoma of more than 10 mm was 38.5% and 55.8 % for Embolization and standard therapy respectively. Concerning Safety: 6.5% deaths in the embolization`s group while 6.3% for standard treatment. Other complications, 6 cases of migraine and 1 case of migration of onyx in superior sagittal sinus with no clinical compromise. 

What is the suggested role of standard surgery then?!!

In brief, Acute Intracranial Tension with clinical compromise and neurological deficits which gives surgery the priority the upper hand as a very satisfying instant relief of symptoms. However, these patients show with a higher morbidity and recurrence. Thus, symptomatic treatment without managing the underlying etiology. 

Unfortunately, still a lot to dig through…...?! Several points were mentioned!

Indications are still under debate. Timing to Intervene. Etiology of recurrence. Bilateral or unilateral embolization. Intervene with or without surgery in some cases.  

Moving to the Live case… 80 years old with a chronic severe headache over about 1 month… on MRI: Bilateral Chronic subdural hematoma with acute on top…. Surgery? Embolization without surgery… maybe?! 

Yes, without an aggravating symptom or neurological deficit operating room is not a suitable option and MMA Embolization can be a good solution.

Some mandatory planning and anatomical considerations were illustrated … what were they?!

• Conscious sedation and Trans radial approach can be achieved.
• Tortuosity of vessels (Can use a distal access catheter in addition)
• Extremely Important Collaterals: 1- Petrosal Branch to the geniculate nucleus of the facial nerve, 2- ophthalmic collaterals through the recurrent meningeal branches of the middle meningeal artery (Most commonly there underneath the sphenoidal wing), 3- Putative dural peel connections and arteriovenous fistulas connections in the normal sinus wall (avoid aggressive liquid embolic injection in order not to embolize the SSS)
• MRI preoperative (To determine bilateral or unilateral approach and detect the aimed branches)

Some mandatory technical tips were illustrated as well… 

1. Going as distal as possible (Never embolize at the level of foramen spinosum due to the petrosal branches origin or region of sphenoidal bone which is dangerous zone of the ophthalmic collaterals)
2. Before Embolization, 50 cc of lidocaine over 30 seconds can be injected especially in conscious sedation to avoid pain of onyx or DMSO. 
3. A wedge flow conditions for embolization by using bigger catheters to avoid reflux. 
4. Using 3 cc syringe to control injection without any overpressure.
5. Inject while pulling back the microcatheter in order avoid embolizing more distally than needed.
6. Adding bony structures to the subtracted images post injection can be helpful to identify the extent of embolization and any untargeted embolization.
7. If the patient is undergoing unilateral side only, it is better to control the contralateral ECA as well before ending the procedure.

Have you ever heard about transvasular drainage of CSDH?! … Sounds weird but exciting!!! 

The technique in brief is First embolizing distal vessels of MMA using liquid embolic like onyx then perforating it using a soft Radiofrequency endovascular wire to be inside the hematoma in subdural space as distal as possible to do a track to push a radiopaque draining catheter and release the blood to outside. Proximal embolization using reintroducing a microcatheter Follows using coils or glue. Point of perforation depends on the hematoma size. Drainage usually left on its own for 10-15 minutes or a syringe can be used. Benefits: No drains or ICU post-op or with possibility of continuation of antiplatelet or anticoagulation. Target: at least 50% to be drained to achieve symptoms relief.