Twenty-first century innovations in neuroradiology treatments

Table 2 Comparison of endovascular techniques

Feature	Microsurgical resection	Early embolic agents (n-BCA)	Modern embolic agents (Onyx, PHIL)
Role	Gold standard for select patients	Adjunct to surgery; can be definitive in select cases	Adjunct or definitive therapy in select cases
Invasiveness	Open surgery	Minimally invasive	Minimally invasive
Mechanism	Direct removal of AVM nidus	Rapid polymerization upon contact with blood	Slow solidification allowing controlled injection and deeper penetration
Effectiveness	High obliteration rates (> 98%)	Used to reduce nidus size and delineate feeders	Higher occlusion rates and reduced need for surgery
Injection control		Difficult due to rapid polymerization	Improved control with prolonged injection
Safety concerns	Limited in deep/complex AVMs; hemorrhagic risk	Catheter entrapment, vessel occlusion	Improved control; safer delivery profile
Technological features		Adhesive embolic agent	Non-adhesive agents with deeper nidus penetration
Microcatheter considerations		Risk of entrapment with early systems	Detachable-tip microcatheters improve safety
Limitations	Limited in deep-seated or complex AVMs	Poor injection control and higher complication risk	Risk of premature tip detachment

nBCA: N-butyl cyanoacrylate; PHIL: Precipitating hydrophobic injectable liquid; AVM: Arteriovenous malformation.