Theoretical comparison of surgery and radiosurgery in cerebral arteriovenous malformations

Management of patients with cerebral arteriovenous malformations (AVMs) is controversial. Excellent surgical results are obtained in patients with low Spetzler-Martin grades, whereas radiosurgery offers a good alternative with its high obliteration rate. In the absence of randomized studies, physicians must choose a treatment plan based on the currently available data. To support this decision-making process, a mathematical model designed to describe patient survival rates after each treatment option was developed.

The theoretical survival curve in patients undergoing conventional surgery, radiosurgery, or observation was calculated. Theoretical life expectancies in patients with AVMs who presented at various initial ages were calculated for each treatment strategy. A systematic method was also developed to compare the estimated risks of various treatment combinations.

Conventional surgery and radiosurgery definitely produced better survival rates than observation. In the comparison of surgery with radiosurgery, radiosurgery was equivalent to surgery with a combined morbidity and mortality rate of approximately 7% for a 20-year-old patient with an unruptured cerebral AVM. Data for other patient ages and treatment combinations are tabulated for use in determining the best treatment strategy. The authors believe that their analysis will provide logical support for the decision-making process involved in the treatment of patients with cerebral AVMs.