INTRADURAL PERIMEDULLARY ARTERIOVENOUS-FISTULAS - RESULTS OF SURGICALAND ENDOVASCULAR TREATMENT IN A SERIES OF 35 CASES

A SERIES OF 35 patients treated for an intradural perimedullary arteri ovenous fistula (AVF) between 1970 and 1990 is reported. Angiography w as performed on all of the patients, leading to the diagnosis. The pat ients were classified into Type I (4 patients), Type II (9 patients), and Type III (22 patients). One Type I patient was not treated, two ot hers underwent surgery, and the last one was embolized. All of the Typ e II AVFs were treated, two by embolization, four by direct surgery, a nd three by surgery after incomplete embolization. All of the Type III AVFs were treated by endovascular detachable silicone balloon. Comple te occlusion of the AVF was achieved in all treated cases of Types I a nd II AVF and in 15 cases of Type III AVF; for the 6 other cases of Ty pe III AVF, incomplete occlusion was achieved. In the Types I and II A VFs, partial improvement was clinically observed in only half of the p atients; the others remained unchanged. The 15 patients whose Type III AVF was completely embolized recovered completely, and four patients with Type III AVF who were incompletely embolized remained unchanged; 2 other patients with Type III AVF worsened after incomplete occlusion , and 1 additional patient died a few hours after an attempt of endova scular occlusion of a cervical Type III AVF. The place of the perimedu llary AVFs among the other vascular malformations involving the spinal cord is discussed according to this classification into three types. Their specific diagnostic and therapeutic difficulties are discussed, resulting in a simplified classification including two types of perime dullary AVF.