Article
Single step pre-embolization of cerebral AVMs and resection in one session: experience in a series of 402 AVM patients
Einzeitige Angiomembolisation und Resektion: Erfahrungen mit einem Konzept innerhalb einer Serie von 402 AVM-Patienten
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Published: | May 8, 2006 |
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Objective: Preoperative embolization of AVMs has been recognized to facilitate microsurgical removal. As embolization and radiotherapy are lengthy procedures, which provide no immediate protection and have a high failure rate, microsurgical resection is still the only proven definitive treatment of AVMs. Therefore anything should be attempted to facilitate resection. Single step endovascular and microsurgical treatment avoids the dilatation of collaterals and reduces the rate of interval hemorrhage.
Methods: The departmental cohort of AVM patients includes 402 patients since 1988. Of these, 355 were actively treated and 47 are followed up for reasons of inoperability, unfavourable associated risks or patients’ choice. 97 patients underwent microsurgical resection without embolization. 33 patients were treated by endovascular means, in 10 patients as curative embolization, 15 as palliative embolization of very large symptomatic AVMs and in 8 as pretreatment to radiotherapy. 215 patients were treated by preoperative embolization with Ethibloc and subsequent resection in one anesthesia (Spetzler-Martin I : 19; II : 58; III : 92; IV : 36; V : 10).
Results: Immediate resection of AVMs after embolization reduced the interval hemorrhage rate to 50% of what has been reported in the literature. Reduction of intranidal pressure by elimination of all hemodynamically relevant feeders, which cannot be reached in the first exposure of the lesion, allows for compression of the AVM to facilitate dissection especially in eloquent regions. White matter perforators were not dilated and collaterals not activated, thus reducing hemorrhagic problems during surgery. In no case, was swelling seen after successful endovascular treatment.
Conclusions: In addition to many technical advances, preembolization has its place in the definitive resective treatment of cerebral AVMs. Combining the endovascular procedure with surgery in one session allows for drastic embolization in one step because the timing reduces the frequency of interval hemorrhage. The hypoxia-induced perilesional angiogenesis is circumvented facilitating the development of a clean dissection plane.