Surgical Treatment For Complications Following Gamma Knife Radiosurgery For Arteriovenous Malformations.Takashi Shuto1, Shigeo Matsunaga2, Jun Suenaga2, Shigeo Inomori2, Hideyo Fujino21Yokohama, Japan 2Yokohama Rosai Hospital, Yokohama, Japan Keywords: cyst, complications, gamma knife, arteriovenous malformation, outcome
Cysts and other late complications can occur after AVM radiosurgery.
To establish the surgical indication and strategy for late complications following gamma knife radiosurgery (GKS) for arteriovenous malformations (AVM).
686 patients who underwent GKS for AVM at our hospital.
We retrospectively studied 10 patients with cyst formation (Group A), 2 patients with expanding hematoma (Group B), and 4 patients with combination of cyst and expanding hematoma (Group C).
Nine male and 7 female patients aged 17 to 42 years (mean 28.3 years) were analyzed. The mean nidus volume was 10.1 ml (0.1-36 ml), and the mean prescription dose at the nidus margin was 20 Gy (18-28 Gy). Complete obliteration of nidus was obtained in 11, partial obliteration in 4, and no change in 1. In group A, although 5 were asymptomatic, 5 were symptomatic such as headache, hemianopia, aphasia, and motor weakness. Expanding hematoma (Group B and C) was associated with surrounding brain edema and symptomatic in all cases. In gourp A, cyst opening in 1 and placement of Ommaya reservoir in 2 cases were necessary. In group B, both 2 patients underwent craniotomy. In group C, 3 of 4 patients received craniotomy. Another patient in group C lost follow up and final outcome was unknown.
This was a retrospective study.
Cyst formation is not rare as late complication of GKS for AVM. Some cyst shows spontaneous regression and the others increase in size gradually and become symptomatic.
Predicting the future course of cyst is difficult. In some case, cyst was asymptomatic although the size was relatively large. The surgery such as placement of Ommaya reservoir should be considered for symptomatic cases. On the other hand, expanding hematoma always increases in size and symptomatic, therefore removal by craniotomy is necessary. Surrounding brain edema decreases rapidly after surgery and recovery of neurological symptom is good. Project Roles:
T. Shuto (), S. Matsunaga (), J. Suenaga (), S. Inomori (), H. Fujino ()