REPERMEATION OF PARTIALLY EMBOLIZED CEREBRAL ARTERIOVENOUS-MALFORMATIONS - A CLINICAL, RADIOLOGIC, AND HISTOLOGIC-STUDY

PURPOSE: To describe the pattern and time course of embolization-relat ed tissue lesions and repermeation of the intranidal cast after endova scular embolization of cerebral arteriovenous malformations (AVMs) wit h N-butyl cyanoacrylate (NBCA), METHODS: We retrospectively reviewed t he records of 26 patients who were treated by endovascular embolizatio n with NBCA and subsequent surgical extirpation to look for embolizati on-related tissue lesions and repermeation of the cast. A residual flo w through the malformation was identified on preoperative angiograms i n every case. RESULTS: Pattern and time course of embolization-related tissue lesions were typical, Until 3 months after embolization, reper meation of embolized structures did not occur, In contrast, repermeati on was found in every patient who had surgery later than 3 months afte r the first embolization (n = 13; 50%). In these cases, histologic exa mination of the resected nidus disclosed capillary structures inside t he lumen of embolized vessels. Capillaries were traced immunohistochem ically with antibodies against membrane-bound factor VIII, No paramete r other than the interval between the first embolization and surgery w as found to relate to the repermeation of the cast. CONCLUSION: Intran idal recapillarization can occur later than 3 months after the first e mbolization with NBCA if total and solid casting of the nidus was not accomplished.