Hj. Pikus et al., MICROSURGICAL TREATMENT OF ARTERIOVENOUS-MALFORMATIONS - ANALYSIS ANDCOMPARISON WITH STEREOTAXIC RADIOSURGERY, Journal of neurosurgery, 88(4), 1998, pp. 641-646
Object. To compare microsurgical and stereotactic radiosurgical treatm
ent of arteriovenous malformations (AVMs), the authors analyzed a pros
pective series of 72 consecutive patients who were treated microsurgic
ally for cerebral AVMs by one neurosurgeon. The authors then compared
the results of microsurgical treatment with published results of stere
otactic radiosurgical treatment of small AVMs. Methods. Patients were
categorized by age, gender, presentation, and preoperative neurologica
l status. The AVMs were categorized by size, location, presence of dee
p venous drainage, and Spetzler-Martin grade. Outcome was assessed for
angiographic obliteration, hemorrhage following treatment, presence o
f a new, persistent postoperative neurological deficit, and Glasgow Ou
tcome Scale (GOS) score. Ordinal logistic regression was used to model
the GOS score and to predict new postoperative deficits. Generalized
estimating equations were used to compare published results of microsu
rgical and stereotactic radiosurgical treatment of AVMs. Kaplan-Meier
event-free survival plots were generated to compare the two modalities
with respect to hemorrhage following treatment. Overall, six patients
(8.3%) exhibited a new persistent neurological deficit postoperativel
y. Sixty-five patients (90.3%) had a GOS score of 5. Three patients we
re moderately disabled and four patients were severely disabled. No pa
tient was observed to be in a vegetative state and there were no treat
ment-related deaths. Seventy-one patients (98.6%) underwent intra-or p
ostoperative angiography. Total excision of the AVM was angiographical
ly confirmed in 70 patients (98.6% of those who underwent angiography)
. To date no patient has suffered from hemorrhage since the microsurgi
cal treatment. When analysis was confined to patients whose AVMs were
smaller than 3 cm in maximum diameter, the authors found a 100% angiog
raphic obliteration rate, no new postoperative neurological deficit, a
nd a good recovery in all patients. An analysis of all patients with S
petzler-Martin Grades I to III resulted in a 100% rate of angiographic
obliteration, one patient with a new postoperative neurological defic
it, and good recovery in 93% of the patients. Size of the AVM, preoper
ative neurological status, and patient age are associated with GOS sco
re (for all, p < 0.02). The Spetzler-Martin grading system as well as
each component of this system are associated with the development of a
new postoperative neurological deficit (for all, p < 0.01). For the e
ntire series there were fewer postoperative hemorrhages and deaths tha
n those mentioned in published series of small AVMs treated with stere
otactic radiosurgery. When these patients and published series of pati
ents with microsurgically treated AVMs classified as Grade I to III we
re compared with similar patients treated radiosurgically there were s
ignificantly fewer postoperative hemorrhages (odds ratio = 0.210, p =
0.001), fewer deaths (odds ratio = 0.659, p = 0.019), fewer new posttr
eatment neurological deficits (odds ratio = 0.464, p = 0.013), and a h
igher incidence of obliteration (odds ratio = 28.2, p = 0.001) for the
microsurgical group. Lifetable analysis confirms the statistically si
gnificant difference in hemorrhage-free survival time between the two
groups (p = 0.002). Conclusions. Based on this analysis, microsurgical
treatment of Grades I to III AVMs is superior to stereotactic radiosu
rgery.