Microsurgical resection of Spetzler-Martin grades 1 and 2 unruptured brain arteriovenous malformations results in lower long-term morbidity and loss of quality-adjusted life-years (QALY) than conservative management--results of a single group series

Abstract

Background: The therapeutic benefits of microsurgery for unruptured brain AVM remain unclear.

Methods: A series of 97 microsurgically resected unruptured brain AVM was analyzed in terms of postoperative morbidity and lifetime loss of quality-adjusted life-years (QALY). For comparison, the natural risk of becoming disabled was modeled on the basis of published data.

Results: Discharge morbidity was recorded in 11 of the 69 of Spetzler-Martin (SM) grade 1 and 2 AVMs (16 %), eight of 22 (36 %) grade 3, and four of six grade 4 (67 %), permanent morbidity >mRS 1 in 3 (4.3 %) grade 1 and 2, four (18 %) grade 3, and three (50 %) grade 4. Treatment inflicted loss of QALY amounted to 0.5 years for SM grade 1-2, 2.5 years grade 3, 7.3 years for grade 4. For the SM grades 1 and 2, the treatment-related loss of 0.5 QALY was met by the natural course after 2.7-4.3 years. For the Spetzler-Martin grades 3 and 4, the treatment-induced loss QALY was not met by the natural risk within a foreseeable time. Permanent morbidity and treatment inflicted loss of QALY of patients younger than 39 years was lower than that of older patients (7 vs. 15 % and 1.0 vs. 2.1 QALY).

Conclusions: Microsurgically managed SM grades 1 and 2 fared better than the modeled natural course but grades 3 and 4 AVM did not benefit from surgery. Younger patients appear to fare more favorably than older patients.