Spinal arteriovenous malformations: new classification and surgical treatment

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Spinal vascular malformations represent rare and insufficiently studied pathological entities characterized by considerable variation. Insufficient study of this disease is connected with the complexity of its diagnosis, which restricts the development of surgical treatments that are differentiated according to the type of malformation. Great difficulties are caused by the lack of a clear structural–hemodynamic classification of spinal arteriovenous malformations (AVMs). At present the classification created between 1991 and 1998 by the combined efforts of different authors is the most widely used one. According to this classification, four categories are distinguishable: Type I, dural arteriovenous fistulas (AVFs); Type II, intramedullary glomus AVMs; Type III, juvenile or combined AVMs; and Type IV, intradural perimedullary AVFs. Vascular tumors are also classified, as follows: hemangiomas, hemangioblastomas, angiosarcomas, hemangiopericytomas, angiofibromas, angiolipomas, and hemangioendotheliomas, as well as cavernous malformations.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>In this study the authors analyze the diagnostic data and results of treatment in 91 patients with AVMs and AVFs who were treated at the Institute of Neurosurgery between 1995 and 2005. The patients' ages ranged from 9 to 83 years; the mean age was 42.9 years. For spinal vascular malformations we devised a classification that took into account the aforementioned features of AVMs: the anatomical characteristics of a malformation and its angiostructural and hemodynamic features. In all patients the neuroimaging modalities used in the investigation of their lesions included magnetic resonance (MR) imaging and selective spinal angiography. Three-dimensional computerized tomography angiography studies were obtained in 14 patients, and MR angiography was used in 17.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>For successful surgical treatment of spinal AVMs it is necessary to obtain data about their localization, vascular structure, and hemodynamics that are as complete as possible. This information will promote the use of optimum surgical procedures and the latest methods of microsurgical and endovascular interventions, with treatments differentiated according to the type of malformation. One should try to use the least invasive endovascular approach in these cases,where possible, to occlude the AVM or reduce the intensity of blood flow by means of embolization. To perform an AVM resection or occlusion, one should use a direct approach to the malformation, blocking only the vessels supplying blood to the malformation and preserving the vessels feeding the spinal cord.</jats:p></jats:sec>

Endovascular management of spinal vascular malformations: history and literature review

“…The subject is further obscured because a plethora of classification systems evolved to categorize these lesions as more recent investigations permitted elucidation of their anatomical and pathophysiological basis. 14,29,32,34,48,62 For the purposes of clarity, this review will largely adhere to the classification system proposed by Oldfield and colleagues, 44,54 which divides these lesions based on their distinct biological characteristics.…”

Study and therapeutic progress on spinal cord perimedullary arteriovenous fistulas

“…In another example, Gekka et al reported the case of a 37-year-old male with simultaneous intramedullary AVMs and PMAVFs at the C3 to C5 level (32). In addition, spinal cord PMAVFs can be classified into ventral and dorsal types (33). This classification has clinical significance; for ventral PMAVFs, a rear-approach surgery can be used, whereas front-approach surgery can be considered for ventral PMAVFs.…”

Imaging diagnosis and the role of endovascular embolization treatment for vascular intraspinal tumors

“…15,95,108 Spinal cord vascular malformations are rarely accompanied by syringohydromyelia and solid enhancement on MRI. 52,105 As for renal cell carcinoma, it can probably be ruled out on the basis of preoperative imaging.…”