Dr. Haytham Hussein .M . Osman ALEX NEURO 2014 SUPERSELECTIVE ANGIOGRAPHY FOR AVM NIDUS BETTER UNDERSTANDING, BETTER RESULTS Dr. Haytham Hussein .M . Osman MD, IMRCS(ed),FINR(Swiss),FEF(NS) Elribat University Hospital Khartoum , Sudan Gamal A . Naser Hospital Alexandria , Egypt

ALEX NEURO 2014

AVM NIDUS: Cerebral AVMs are complex and only partially understood vascular lesions with a natural history characterized by significant morbidity and mortality mainly due to an increased hemorrhagic risk. The main angio-architectural characteristic of cerebral AVMs distinguishing them is the shunting between arteries and veins, which exhibit mature vessel wall elements constituting the so-called nidus

Barows Inst ,Mayfield clinic

Angio-architecture of Brain AVM: Feeding arteries Geometric Types Anatomic Types Draining veins Single Multiple Main Accessory Nidus Angio-architecture

Efficient Treatment: Efficient endovascular treatment of cerebral AVMs in this regard, embolisation advanced from a simple endovascular technique initially conceived to block feeding arteries of AVMs to a complex sophisticated one with the aim to use appropriately and carefully selected feeding arteries as vascular access roots to super- selectively reach and obliterate the core, i.e. the nidus of the AVMs containing the arteriovenous shunting area . Valavanis A, Yasargil MG. The Endovascular Treatment of brain Arteriovenous Malformations. Adv Tech Stand Neurosurg 1998;24:131–214.

Embolization of Nidus cures the AVM

FEEDING ARTERIES Geometric Types: Direct: Indirect: Transit Terminal(mono , multi) Pseudo-terminal. Indirect: Transit Retrograde collateral feeding Arts Anatomic Types:Pial , Dural(Meningeal), Retrograde , Perforating and Choroidal

Direct & Indirect Art Feeders

Suplementry,collateral & retrograde leptomeningeal supply

THE NIDUS Angio-architecture Size Shape Vascular composition Intranidal Vascular cavities

Nidus Angioarchitecture Dopman(1971) introduced the term” NIDUS” “ Nidus represent that area of entire AVM angioarchitecture , interposed between the readily identifiable distal segments of the feeding arteries and emerging proximal segments of draining veins where AV shunting occures .” Dopman 1971, Yasargil 1987, Berenstien and Lasjaunias 1991, Haudart et al 1993, Valavanis 1996

Size of Nidus Varies from very small to giant. It represents a major component of most Surgical AVM classifications. From the prospective of endovascular treatment the size is not of major importance.

Shape of Nidus Shape is determined by the space or anatomic structure within which it is located: Sulcal pyramidal Fissural more linear etc.

Composition Hamby (1958) considered the nidus to be a complex vascular system of coiling and intercommunicating vascular channels that empty into thin-walled torutous veins Out of 387 cases (3550 injections) by Valavanis: Pure Plexiform (36%) Mixed plexiform and fistulous (53%) Pure Fistulous (11%)

Plexiform & Fistulous Nidi

Compartments One vein (compartmental vein) Multi Mono With or without inter-compartmental communication

Intranidal Cavities Arterial cavities Venous cavities Aneurysms. Pseudo-aneurysms(post-hemorrhagic) Loops. Venous cavities Pseudo-aneurysms (post-hemorrhagic) Ectasias/Varices: Open exit or Closed exit

DRAINING VEINS Usually predicted from location of the AVM Superficial AVMs drain through cortical veins Sub-cortical through both cortical and deep Deep through deep sub-ependymal veins

Draining veins Single: compartmental Multiple Main : large compartment Accessory : small compartment “Anatomic variations of the venous system occur in 30%-32% of cases of cerebral AVMs” Lasjaunias et al. 1986,Willinsky et al 1988, Yasargil 1987

Associated Venous Findings and Venous High-Flow Angiopathy Hemodynamic disturbance(venous hypertention) Stenoses. Ectasias. Collateral Venous circulation. Competition between the venous drainage of the AVM Nidus and normal brain. Hydrovenous Disorders (impaired CSF re- absorbtion) Lasjaunias et al 86,91,Yasargil 87,Berenstein and Lasjaunias 91,Vidyaasagar 79,Willinsky 88

F 21Y Ventricular hemorrhage

22 Y M Rt handed C/O Seizures Lt frontal sulcal AVM(feeder precentral Art)

13 Y F SAH AVM Lt Thalamus.(2 sessions) Feeders :Thalamo-perforating, L , M post.Ch art & Thalamo-geniculate

Conclusion Efficient endovascular treatment of the cerebral AVMs is to super-selectively reach and obliterate the core, i.e. the nidus of the AVMs containing the arteriovenous shunting area . Super-selective DSA helps protecting the normal brain. To achieve your goal choose the appropriate micr-ocatheters and Embolization materials. Learning curve process. Better understanding ,Better results

KHARTOUM,SUDAN