Therapy of AVMs: a decision analysis.

A DA tree representing the possible outcomes of a real-life scenario of decision-making with an AVM has been constructed and presented. Baseline values for a young female with a grade 2 (Spetzler) AVM were drawn from the literature, and when computed in a decision tree, favor open surgical resection. Sensitivity analysis was performed by dividing lesions into small (< 3 cm) and large (> or = 3 cm) categories. With small and large AVMs that were Spetzler grade 3 or less, open surgery was favored over SRNS, delayed therapy, embolization plus therapy, or the natural history of the disease. However, with increasing risk of anesthesia (ASA grade 3 or greater), SRNS becomes a more reasonable therapy for small AVMs (less than 3 cm.). For large AVMs (greater than 3 cm), open surgical resection is favored for Spetzler grade 2 and 3 AVMs, depending on the patient's age and anesthesia risk. However, for large and complex lesions (Spetzler grades 4 and 5), SRNS is favored despite low cure rates (50%). At no time were natural history, delayed therapy, or embolization therapy favored. In the future, cost may be factored into the analysis as well. The complexity of that evaluation is beyond the scope of this report; however, DA is especially equipped to deal with financial analysis of such questions, because the technique has been borrowed from the business community. In the spirit of the "winds of change," techniques will continue to improve, and other modalities may be found for therapy, requiring further analysis of the therapy of AVMs. As more difficult and complex alternatives become available, DA may play an integral role in sorting these complex issues of patient care.