Letters to the Editor / Clinical Neurology and Neurosurgery 116 (2014) 104–108
patients receiving a clopidogrel load prior to a neurointerventional procedure had less than 20% inhibition of platelet aggregation [5]. Similarly, aspirin resistance was reported by Hovens et al. to be prevalent in 24% of the population [6]. In light of these findings, our institution routinely performs platelet function assays after administration of antiplatelet medications for neuroendovascular procedures [7]. References [1] Scholz C, Hubbe U, Deininger M, Deininger MH. Hemorrhage rates of external ventricular drain (EVD), intracranial pressure gauge (ICP) or combined EVD and ICP gauge placement within 48 h of endovascular coil embolization of cerebral aneurysms. Clin Neurol Neurosurg 2013;115(8):1399–402. [2] Lanterna LA, Tredici G, Dimitrov BD, Biroli F. Treatment of unruptured cerebral aneurysms by embolization with guglielmi detachable coils: case-fatality, morbidity, and effectiveness in preventing bleeding – a systematic review of the literature. Neurosurgery 2004;55(4):767–75, discussion 775–8. [3] Yamada NK, Cross DT, 3rd TK, Pilgram CJ, Moran CP, Derdeyn RG, et al. Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms. AJNR Am J Neuroradiol 2007;28(9): 1778–82. [4] Oxley TJ, Dowling RJ, Mitchell PJ, Davis S, Yan B. Antiplatelet resistance and thromboembolic complications in neurointerventional procedures. Front Neurol 2011;2:83. [5] Nordeen JD, Patel AV, Darracott RM, Johns GS, Taussky P, Tawk RG, et al. Clopidogrel resistance by P2Y12 platelet function testing in patients undergoing neuroendovascular procedures: incidence of ischemic and hemorrhagic complications. J Vasc Interv Neurol 2013;6(1):26–34. [6] Hovens MM, Snoep JD, Eikenboom JC, van der Bom JG, Mertens BJ, Huisman MV. Prevalence of persistent platelet reactivity despite use of aspirin: a systematic review. Am Heart J 2007;153(2):175–81. [7] Harrison P. Platelet function analysis. Blood Rev 2005;19(2):111–23.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville, VA 22908, United States ∗ Correspondence to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville, VA 22908, United States. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected]
1 August 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.08.032
Microsurgical resection versus endovascular embolization for acutely ruptured cerebellar arteriovenous malformations Keywords: Intracranial arteriovenous malformation Intracranial hemorrhages Cerebellum Stroke Endovascular procedures
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Raghavan et al. titled ‘Ruptured middle cerebellar peduncle AVM presenting with a coma treated to complete recovery with endovascular and intensive care therapy: Discussion of management’ [1]. The authors report a case of an 18 year-old who presented with sudden onset coma secondary to a large cerebellar hematoma with resultant obstructive hydrocephalus. Angiography demonstrated a ruptured,
105
compact cerebellar arteriovenous malformation (AVM) located in the superior cerebellar peduncle (SCP) draining into the superior petrosal vein with multiple intranidal aneurysms. The hydrocephalus was treated with temporary cerebrospinal fluid diversion through an external ventricular drain, and the AVM was completely embolized in a single session with Onyx. Angiographic follow-up at eight months demonstrated persistent total AVM obliteration, and clinical follow-up at 11 months showed complete recovery of neurological function. The authors suggest that due to the deep location of the AVM in the SCP, large associated hematoma, and poor clinical presentation, the patient’s expected surgical outcome would have been poor. Lawton et al. proposed a supplementary AVM grading scale, based on patient age, AVM morphology, and history of hemorrhage, which demonstrated higher predictive accuracy for surgical AVM outcomes than the Spetzler-Martin grading scale [2]. The same group subsequently confirmed the improved predictive capability of the supplementary grading scale over the Spetzler-Martin grading scale for a cohort of 60 surgically resected cerebellar AVMs [3]. Although the AVM in this case was grade II based on the SpetzlerMartin classification system, its supplementary grade was I. In an AVM microsurgery series of 300 patients, the rate of postoperative neurological deterioration was 24% for Spetzler-Martin grade II lesions (30/123 patients) compared to only 4% for supplementary grade I lesions (1/27 patients) [2]. Therefore in the modern era, predicting AVM surgical outcomes using the Spetzler-Martin grade alone may be insufficient, especially for those located in the cerebellum. Stemer et al. reported 21 ruptured AVMs, which were acutely embolized with Onyx [4]. Although complete obliteration was achieved in 52%, only 33% were cured in a single procedure, and the procedural complication rate was 10%. For ruptured cerebellar AVMs, surgical resection provides the best chance of rapid neurological recovery and AVM obliteration. Until endovascular technology improves the safety and efficacy of AVM embolization, it will remain primarily an adjuvant therapy for these lesions. References [1] Raghavan K, Nee AC, Shahi K, Hacein-Bey L. Ruptured middle cerebellar peduncle AVM presenting with a coma treated to complete recovery with endovascular and intensive care therapy: discussion of management. Clin Neurol Neurosurg 2013;115(10):2291–5. [2] Lawton MT, Kim H, McCulloch CE, Mikhak B, Young WL. A supplementary grading scale for selecting patients with brain arteriovenous malformations for surgery. Neurosurgery 2010;66(4):702–13 [discussion 713]. [3] Rodriguez-Hernandez A, Kim H, Pourmohamad T, Young WL, Lawton MT. Cerebellar arteriovenous malformations: anatomic subtypes, surgical results, and increased predictive accuracy of the supplementary grading system. Neurosurgery 2012;71(6):1111–24. [4] Stemer AB, Bank WO, Armonda RA, Liu AH, Herzig DW, Bell RS. Acute embolization of ruptured brain arteriovenous malformations. J Neurointerv Surg 2013;5(3):196–200.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville 22908, United States ∗ Correspondence to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville 22908, USA. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected]
7 October 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.10.025
patients receiving a clopidogrel load prior to a neurointerventional procedure had less than 20% inhibition of platelet aggregation [5]. Similarly, aspirin resistance was reported by Hovens et al. to be prevalent in 24% of the population [6]. In light of these findings, our institution routinely performs platelet function assays after administration of antiplatelet medications for neuroendovascular procedures [7]. References [1] Scholz C, Hubbe U, Deininger M, Deininger MH. Hemorrhage rates of external ventricular drain (EVD), intracranial pressure gauge (ICP) or combined EVD and ICP gauge placement within 48 h of endovascular coil embolization of cerebral aneurysms. Clin Neurol Neurosurg 2013;115(8):1399–402. [2] Lanterna LA, Tredici G, Dimitrov BD, Biroli F. Treatment of unruptured cerebral aneurysms by embolization with guglielmi detachable coils: case-fatality, morbidity, and effectiveness in preventing bleeding – a systematic review of the literature. Neurosurgery 2004;55(4):767–75, discussion 775–8. [3] Yamada NK, Cross DT, 3rd TK, Pilgram CJ, Moran CP, Derdeyn RG, et al. Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms. AJNR Am J Neuroradiol 2007;28(9): 1778–82. [4] Oxley TJ, Dowling RJ, Mitchell PJ, Davis S, Yan B. Antiplatelet resistance and thromboembolic complications in neurointerventional procedures. Front Neurol 2011;2:83. [5] Nordeen JD, Patel AV, Darracott RM, Johns GS, Taussky P, Tawk RG, et al. Clopidogrel resistance by P2Y12 platelet function testing in patients undergoing neuroendovascular procedures: incidence of ischemic and hemorrhagic complications. J Vasc Interv Neurol 2013;6(1):26–34. [6] Hovens MM, Snoep JD, Eikenboom JC, van der Bom JG, Mertens BJ, Huisman MV. Prevalence of persistent platelet reactivity despite use of aspirin: a systematic review. Am Heart J 2007;153(2):175–81. [7] Harrison P. Platelet function analysis. Blood Rev 2005;19(2):111–23.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville, VA 22908, United States ∗ Correspondence to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville, VA 22908, United States. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected]
1 August 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.08.032
Microsurgical resection versus endovascular embolization for acutely ruptured cerebellar arteriovenous malformations Keywords: Intracranial arteriovenous malformation Intracranial hemorrhages Cerebellum Stroke Endovascular procedures
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Raghavan et al. titled ‘Ruptured middle cerebellar peduncle AVM presenting with a coma treated to complete recovery with endovascular and intensive care therapy: Discussion of management’ [1]. The authors report a case of an 18 year-old who presented with sudden onset coma secondary to a large cerebellar hematoma with resultant obstructive hydrocephalus. Angiography demonstrated a ruptured,
105
compact cerebellar arteriovenous malformation (AVM) located in the superior cerebellar peduncle (SCP) draining into the superior petrosal vein with multiple intranidal aneurysms. The hydrocephalus was treated with temporary cerebrospinal fluid diversion through an external ventricular drain, and the AVM was completely embolized in a single session with Onyx. Angiographic follow-up at eight months demonstrated persistent total AVM obliteration, and clinical follow-up at 11 months showed complete recovery of neurological function. The authors suggest that due to the deep location of the AVM in the SCP, large associated hematoma, and poor clinical presentation, the patient’s expected surgical outcome would have been poor. Lawton et al. proposed a supplementary AVM grading scale, based on patient age, AVM morphology, and history of hemorrhage, which demonstrated higher predictive accuracy for surgical AVM outcomes than the Spetzler-Martin grading scale [2]. The same group subsequently confirmed the improved predictive capability of the supplementary grading scale over the Spetzler-Martin grading scale for a cohort of 60 surgically resected cerebellar AVMs [3]. Although the AVM in this case was grade II based on the SpetzlerMartin classification system, its supplementary grade was I. In an AVM microsurgery series of 300 patients, the rate of postoperative neurological deterioration was 24% for Spetzler-Martin grade II lesions (30/123 patients) compared to only 4% for supplementary grade I lesions (1/27 patients) [2]. Therefore in the modern era, predicting AVM surgical outcomes using the Spetzler-Martin grade alone may be insufficient, especially for those located in the cerebellum. Stemer et al. reported 21 ruptured AVMs, which were acutely embolized with Onyx [4]. Although complete obliteration was achieved in 52%, only 33% were cured in a single procedure, and the procedural complication rate was 10%. For ruptured cerebellar AVMs, surgical resection provides the best chance of rapid neurological recovery and AVM obliteration. Until endovascular technology improves the safety and efficacy of AVM embolization, it will remain primarily an adjuvant therapy for these lesions. References [1] Raghavan K, Nee AC, Shahi K, Hacein-Bey L. Ruptured middle cerebellar peduncle AVM presenting with a coma treated to complete recovery with endovascular and intensive care therapy: discussion of management. Clin Neurol Neurosurg 2013;115(10):2291–5. [2] Lawton MT, Kim H, McCulloch CE, Mikhak B, Young WL. A supplementary grading scale for selecting patients with brain arteriovenous malformations for surgery. Neurosurgery 2010;66(4):702–13 [discussion 713]. [3] Rodriguez-Hernandez A, Kim H, Pourmohamad T, Young WL, Lawton MT. Cerebellar arteriovenous malformations: anatomic subtypes, surgical results, and increased predictive accuracy of the supplementary grading system. Neurosurgery 2012;71(6):1111–24. [4] Stemer AB, Bank WO, Armonda RA, Liu AH, Herzig DW, Bell RS. Acute embolization of ruptured brain arteriovenous malformations. J Neurointerv Surg 2013;5(3):196–200.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville 22908, United States ∗ Correspondence to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville 22908, USA. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected]
7 October 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.10.025
