Multidisciplinary Approach to Arteriovenous Malformations

Abstract

The treatment of arteriovenous malformations (AVMs) depends on the efforts of a multidisciplinary team whose ultimate goal is to achieve better results when compared to the natural history of the pathology. The role of adjuvant treatment modalities such as radiosurgery and endovascular embolization is discussed. Treatment strategies and surgical results from a personal series of 344 patients operated in a 10-year period are reviewed. The Spetzler and Martin classification was modified to include subgroups IIIA (large size grade III AVMs) and IIIB (small grade III AVMs in eloquent areas) to assist the surgical resection criteria. The treatment strategy followed was surgery for grades I and II, embolization plus surgery for grade IIIA, radiosurgery for grade IIIB, and conservative for grades IV and V. According to the new proposed classification 45 (13%) patients were grade I, 96 (28%) were grade II, 44 (13%) grade IIIA, 97 (28%) grade IIIB, 45 (13%) grade IV, and 17 (5%) were grade V. As for surgical results 85.8% of the patients had a good outcome (no additional neurological deficit), 12.5% had a fair outcome (minor neurological deficit), 0.6% had a bad outcome (major neurological deficit), and 1.2% died. These figures indicate that the treatment of AVMs can achieve better results compared to the natural history if managed by a well trained group of specialists led by an experienced neurosurgeon.

Management of Arteriovenous Malformations Related to Spetzler-Martin Grading System

“…For instance, Hamilton and Spetzler 39 had good results in 96 and 100% of patients in early and late postoperative periods, respectively. Similar outcomes were reported by Heros et al, 50 with excellent or good results in 94% of patients harboring AVMs at this grade, and by de Oliveira et al, 51 with good outcome in 98% of patients with grade II AVMs. Sisti et al 52 reported good recovery with no morbidity in 96% of 25 patients with AVMs that had a nidus size <3 cm and located in eloquent areas.…”

A Comprehensive Review of Radiosurgery for Cerebral Arteriovenous Malformations: Outcomes, Predictive Factors, and Grading Scales

“…The modified Spetzler-Martin (mSM) grading system was put forth to address the discrepancies between the SM grade and patient outcomes, specifically with regard to grade III [6] . The mSM recognizes that AVMs of grade III present different challenges according to their location/size and introduces two subgroups: grade IIIA (grade III due to size 1 6 cm) and grade IIIB (grade III due to venous drainage and/or eloquence).…”

“…The mSM recognizes that AVMs of grade III present different challenges according to their location/size and introduces two subgroups: grade IIIA (grade III due to size 1 6 cm) and grade IIIB (grade III due to venous drainage and/or eloquence). A recommended treatment plan is embolization to reduce the size of grade IIIA lesions so that they can be treated with microsurgery, and radiosurgery for grade IIIB lesions [6] . Other modifications to SM grade III patients have been suggested to better define appropriate surgical treatment [33] .…”

The Radiosurgical Treatment of Arteriovenous Malformations: Obliteration, Morbidities, and Performance Status

“…Radiosurgery-associated morbidities include seizures, headaches, neurologic deficits, and radiationinduced cerebral injury such as cysts or neoplasms. Moreover, the effect of irradiation manifests over a latency period of 1 to 3 years (7,8), during which it has been shown (9, 10) that the risk of rebleeding remains constant and can be eliminated only by complete obliteration. Both the long latency period and the requirement of angiography to demonstrate cure have rendered follow-up especially difficult in large cohorts of AVM patients.…”