Surgical treatment of intracranial arteriovenous malformations with an analysis of cost-effectiveness.
Decision making with cerebral AVMs is one of the most difficult aspects of neurosurgical practice. A diversity of factors, such as the size and location of the AVM; the patient's age, medical, and neurologic condition; and his occupation, hobbies, and expectations, as well as his psychological makeup, must be considered. In addition, a thorough understanding of the natural history is necessary. There is no possible substitution for individual case-by-case analysis since every AVM and every patient is different. Currently, we have excellent information about the natural history of cerebral AVMs. It appears that they bleed at a rate of 3 to 4% per year whether they have bled before or not. The risk of rehemorrhage after a hemorrhage is only slightly higher during the first year (6%), and after that it is the same as for AVMs that have not bled. The serious morbidity associated with each hemorrhage is about 30% and the mortality about 12.5%. Modern surgical results indicate that all but the very large cerebral AVMs and those AVMs that involve critical deep structures, such as the internal capsule and the brainstem, can be excised with satisfactory results. For grade I to IV AVMs (Spetzler and Martin grading system (51)) a combined morbidity and mortality rate of less than 10% can generally be expected. The surgery of grade V AVMs is accompanied by very substantial morbidity and generally should not be recommended, except for patients who have a significant pre-operative deficit or who have had multiple hemorrhages or a gradually progressing deficit. There are many different causes of morbidity accompanying surgical excision of cerebral AVMs. Of these, probably the most important is faulty surgical judgment, although technical problems do arise frequently, even for the most experienced surgeons. Pre-operative embolization is a significant source of morbidity and mortality, and it should be used only when it is expected that the combined morbidity and mortality of embolization and surgery is less than the risk for surgery alone. Surgical excision of "operable" cerebral AVMs, preceded by embolization in selected cases, is highly cost-effective when compared to observation alone or to a policy of surgery for large- and medium-sized lesions and radiosurgery for small (< 3 cm) lesions. This conclusion assumes that an experienced team performs the surgery and embolization, as well as the selection of patients for surgery with or without embolization. Operable small (< 3 cm) AVMs should be treated by surgical excision; when compared to radiosurgery or observation alone, surgical excision is highly cost-effective and very efficacious in prolonging quality-life expectancy. This conclusion assumes that an experienced cerebrovascular surgeon makes the judgment of operability (selection for surgery) and then performs the operation.
Nussbaum
E S
ES
Department of Neurosurgery, University of Minnesota, Minneapolis, USA.
Heros
R C
RC
Camarata
P J
PJ
D003362:Cost-Benefit Analysis; D003657:Decision Making; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D012307:Risk Factors