Adenosine-induced Asystole during AVM Embolization : A Case Series

Abstract

Background: Adenosine induced cardiac standstill has been used intraoperatively for both aneurysm and arteriovenous malformation (AVM) surgery and embolization. We sought to report the results of adenosine induced cardiac standstill as an adjunct to endovascular embolization of brain AVMs.

Material and methods: We retrospectively identified patients in our prospectively maintained database to identify all patients since January 2007 in whom adenosine was used to induce cardiac standstill during the embolization of a brain AVM. We recorded demographic data, clinical presentation, Spetzler Martin grade, rupture status, therapeutic intervention and number of embolization sessions, angiographic and clinical results, clinical and radiological outcomes and follow-up information.

Results: We identified 47 patients (22 female, 47%) with average age 42 ± 17 years (range 6-77 years) who had undergone AVM embolization procedures using adjunctive circulatory standstill with adenosine. In total there were 4 Spetzler Martin grade 1 (9%), 9 grade 2 (18%), 15 grade 3 (32%), 8 grade 4 (18%), and 11 grade 5 (23%) lesions. Of the AVMs six were ruptured or had previously ruptured. The average number of embolization procedures per patient was 5.7 ± 7.6 (range 1-37) with an average of 2.6 ± 2.2 (range 1-14) embolization procedures using adenosine. Overall morbidity was 17% (n = 8/47) and mortality 2.1% (n = 1/47), with permanent morbidity seen in 10.6% (n = 5/47) postembolization. Angiographic follow-up was available for 32 patients with no residual shunt seen in 26 (81%) and residual shunts seen in 6 patients (19%). The angiographic follow-up is still pending in 14 patients. At last follow-up 93.5% of patients were mRS ≤2 (n = 43/46).

Conclusion: Adenosine induced cardiac standstill represents a viable treatment strategy in high flow AVMs or AV shunts that carries a low risk of mortality and permanent neurological deficits.

Keywords: AVM; Adenosine; Asystole; Embolization; Resection.

Fig. 1

A patient with a left thalamic and ganglion AVM as demonstrated on the axial TOF MRA (a). Supply to the AVM was derived from the posterior circulation (b) and the anterior circulation (c) after contrast injection into the vertebral and internal carotid arteries respectively. On the delayed angiographic images, predominantly deep venous drainage was seen (d)

Fig. 2

Multiple embolizations were undertaken over a period of several months. Microcatheter angiography via the anterior choroidal artery (a) demonstrated rapid shunting. Embolization under asystole (16 s) resulted in good nidal penetration and glue cast formation (b). A further embolization via the posterolateral choroidal branch (c, d) but without induced asystole resulted in poor nidal penetration

Fig. 3

The angiographic appearances pre-embolization (a) and post-multiple embolization sessions including those performed under asystole demonstrated a significant reduction in the volume of the nidus (b). An axial T2-weighted magnetic resonance imaging (MRI) post-embolization demonstrated continued shunting but no major infarction (c). Gamma knife radiosurgery was performed to complete the treatment, which caused some perinidal edema. (d) At year 4 post-radiosurgery there was complete obliteration of the AVM (e)