Radiosurgery Facilitates Resection of Brain Arteriovenous Malformations and Reduces Surgical Morbidity

Abstract

OBJECTIVE-Stereotactic radiosurgery makes brain arteriovenous malformations (AVM) more manageable during their microsurgical resection. To better characterize these effects, we compared results of microsurgical resection of radiated (RS + ) and non-radiated (RS − ) AVMs to demonstrate that prior radiosurgery facilitates surgery and decreases operative morbidity.METHODS-From of series of 344 patients who had AVM resections at the University of California, San Francisco (1997-2007, 21 RS + patients were matched with 21 RS − patients based on pre-treatment clinical and AVM characteristics. Matching was blinded to outcomes, which were assessed with the modified Rankin Scale (mRS).RESULTS-Mean AVM volume was reduced by 78% (P<0.01) and Spetzler-Martin grades were reduced in 52% of RS + patients (P < 0.001). Preoperative embolization was used less in RS + than in RS − patients (P< 0.001). Mean operative time (P< 0.01), blood loss (P < 0.05), and length of hospital stay (P< 0.05) were lower in the RS + group. Surgical morbidity was 14% higher in RS − patients, and they had significant worsening in mRS scores after surgery while RS + patients did not (P<0.01). RS + patients deteriorated between AVM diagnosis and surgery due to hemorrhages during the latency period (P< 0.05).CONCLUSION-Prior radiosurgery facilitates AVM microsurgery and decreases operative morbidity. Radiosurgery is recommended for unruptured AVMs that are not favorable for microsurgical resection. Microsurgical resection is recommended for radiated AVMs that are not completely obliterated after the 3-year latency period, but altered favorably for surgery, even in asymptomatic patients. Prompt resection of persistent AVMs should be considered to avoid the risk of post-latency hemorrhage and to optimize patient outcomes.

Volume-staged radiosurgery for large arteriovenous malformations: an evolving paradigm

“…Surgery, which remains the gold standard for safely resectable lesions, has been used with good outcomes in the salvage setting for initially unresectable AVMs. 1,33 Radiosurgery reduces the volume of the nidus as well as possibly the operative morbidity in previously unresectable lesions. Our goal is, in part, to facilitate surgery since most patients will not experience obliteration after VS-SRS, which has been demonstrated in all series on these large lesions, or patients will experience obliteration only in a protracted manner.…”

A treatment paradigm for high-grade brain arteriovenous malformations: volume-staged radiosurgical downgrading followed by microsurgical resection

“…Microsurgery has been used effectively and with reduced morbidity as a salvage technique after SS-SRS. 24,29 Included in these reports are patients treated with additional sessions of SRS to residual AVM at the end of the latency period, which differs from upfront volume-staged therapy. However, the planned combination of VS-SRS plus microsurgery has not been evaluated as part of a treatment paradigm for inoperable high-grade AVMs.…”

Role of Stereotactic Radiosurgery in the Treatment of High-Grade Cerebral Arteriovenous Malformation

“…The complete obliteration rate after volume-staging radiosurgery was low, 12,45) but surgical removal of incompletely obliterated nidus after this approach appears to be a good treatment strategy because surgical resection of an ir- radiated nidus is feasible and safe. 39) Recently, the combination of initial embolization for large AVM to reduce the nidus volume, followed by SRS, resulted in 76% obliteration of the total nidus on imaging, 2) which might be acceptable for such challenging lesions. On the other hand, the morbidity according to treatment was described as 18% per procedure.…”