Downloaded from http://jnis.bmj.com/ on June 21, 2015 - Published by group.bmj.com
Hemorrhagic stroke
ORIGINAL RESEARCH
Pipeline Embolization Device as primary treatment for blister aneurysms and iatrogenic pseudoaneurysms of the internal carotid artery John D Nerva,1 Ryan P Morton,1 Michael R Levitt,1 Joshua W Osbun,1 Manuel J Ferreira,1 Basavaraj V Ghodke,1,2 Louis J Kim1,2 1
Department of Neurological Surgery, Harborview Medical Center, University of Washington, Seattle, Washington, USA 2 Department of Radiology, Harborview Medical Center, University of Washington, Seattle, Washington, USA Correspondence to Dr Louis J Kim, Department of Neurological Surgery, Harborview Medical Center, UW Medicine, 325 9th Ave, Box 359924, Seattle, WA 98104, USA; [email protected] Received 1 December 2013 Revised 27 January 2014 Accepted 31 January 2014 Published Online First 27 February 2014
ABSTRACT Background Blood blister type aneurysms (BBAs) and pseudoaneurysms create a unique treatment challenge. Despite many advances in open surgical and endovascular techniques, this subset of patients retains relatively high rates of morbidity and mortality. Recently, BBAs have been treated with flow-diverting stents such as the Pipeline Embolization Device (PED) with overall positive results. Methods Four patients presented with dissecting internal carotid artery (ICA) aneurysms treated with the PED (two BBAs presenting with subarachnoid hemorrhage (SAH), two pseudoaneurysms after injury during endoscopic trans-sphenoidal tumor surgery). Results Three patients had a successful angiographic and neurological outcome. One patient with a BBA re-ruptured during initial PED placement, again in the postoperative period, and later died. Primary PED treatment involved telescoping stents in two patients and coil embolization supplementation in one patient. Conclusions The PED should be used selectively in the setting of acute SAH. Dual antiplatelet therapy can complicate hydrocephalus management, and the lack of immediate aneurysm occlusion creates the risk of shortterm re-rupture. PED treatment for iatrogenic ICA pseudoaneurysms can provide a good angiographic and neurological outcome.
INTRODUCTION
To cite: Nerva JD, Morton RP, Levitt MR, et al. J NeuroIntervent Surg 2015;7:210–216. 210
The Pipeline Embolization Device (PED) (ev3, Irvine, California, USA) is a flow-diverting stent (FDS) designed for the treatment of intracranial aneurysms. FDSs redirect blood flow to promote stasis and delayed thrombosis within the aneurysm and reconstruction of the parent artery. In contrast to coil embolization and microsurgical approaches, the aneurysm is not immediately occluded, but rather the FDS reduces flow into the aneurysm promoting thrombosis and eventual endothelialization.1 FDSs require dual antiplatelet therapy until endothelialization occurs in order to minimize thromboembolic complications. As such, the use of the PED in acute subarachnoid hemorrhage (SAH) is controversial.2 3 In the setting of acute SAH, FDSs have been used for aneurysms with difficult morphologies, including blood blister type aneurysms (BBAs) and dissecting aneurysms.2–9 BBAs are small broad-based lesions typically occurring at non-branching sites of the supraclinoid internal carotid artery (ICA).10 11 They account for
0.3–1.7% of ICA aneurysms10–12 and 2.2% of SAH from a ruptured ICA aneurysm.13 Histologically, BBAs show focal arterial wall defects of the internal elastic lamina and media, which leaves a thin layer of fibrous tissue and adventitia protecting the defect, similar to pseudoaneurysms.4 14 The exact pathogenesis is unknown, but focal arterial dissections and penetrating ulcers from atherosclerosis have been implicated.13 15 Numerous surgical and endovascular treatment strategies have been employed, but BBAs remain challenging to treat due to their small size, broad-base and thin fragile walls.2 16 These anatomical features, in combination with a potentially malignant course defined by rapid growth with a high risk of perioperative rupture, further complicate treatment. ICA pseudoaneurysms from iatrogenic injury during endoscopic trans-sphenoidal surgery can result from local dissections and direct injury to the ICA. They are similar to BBAs histologically (including focal artery laceration), geographically (occurring at non-branching sites of the ICA) and in the possibility for rapid enlargement and rupture. In one trans-sphenoidal surgical series, pseudoaneurysms accounted for 3 of 21 vascular injuries in 1800 patients.17 These pseudoaneurysms are typically seen immediately on angiography after intraoperative arterial bleeding, but may also develop in a delayed fashion from a postoperative focal arterial stenosis.17 18 They may also occur in cases without intraoperative arterial hemorrhage, from denuding of the vessel during tumor resection.19 Endovascular techniques have been employed more recently to treat iatrogenic ICA pseudoaneurysms, and the major risks of treatment are due to thin fragile pseudoaneurysm walls and rapid enlargement and recurrence after treatment.20 21 As such, iatrogenic ICA pseudoaneurysms may pose similar intraoperative and perioperative risks to BBAs. Amenta et al22 reported the first case of PED placement for treatment of an ICA pseudoaneurysm from endoscopic sinus surgery. Parent artery reconstruction with FDS has not been reported for the treatment of iatrogenic ICA pseudoaneurysms after endoscopic trans-sphenoidal tumor surgery, where the major difference is the intracranial surgical manipulations that occur during this type of procedure. This has significant implications related to dual antiplatelet therapy. This report highlights PED use in the treatment of these complex aneurysm subtypes of the ICA,
Nerva JD, et al. J NeuroIntervent Surg 2015;7:210–216. doi:10.1136/neurintsurg-2013-011047
Downloaded from http://jnis.bmj.com/ on June 21, 2015 - Published by group.bmj.com
Hemorrhagic stroke with two cases of ruptured BBAs and two cases of iatrogenic pseudoaneurysms.
METHODS All patients were treated at our medical center after review by our multidisciplinary team, which includes endovascular neurosurgeons and interventional neuroradiologists. The cases were retrospectively reviewed. The two patients with BBA presented with SAH and the two patients with pseudoaneurysms occurred after injury during endoscopic trans-sphenoidal tumor surgery (table 1). Open surgical treatment with surgical bypass and trapping and endovascular treatment modalities were discussed with the patients and/ or their families. All cases were reviewed by providers with expertise in open surgical and endovascular management. Based on these discussions and careful consideration of the potential risks and benefits of each modality, endovascular treatment with the PED was elected. Patients were loaded with aspirin 325 mg and clopidogrel 75 mg at least 24 h prior to PED placement. Platelet reactivity testing was performed before the procedure using the VerifyNow point-of care platelet assay (Accumetrics, San Diego, California, USA) which measures the degree of platelet inhibition by aspirin and clopidogrel. Adequate inhibition was defined as
Hemorrhagic stroke
ORIGINAL RESEARCH
Pipeline Embolization Device as primary treatment for blister aneurysms and iatrogenic pseudoaneurysms of the internal carotid artery John D Nerva,1 Ryan P Morton,1 Michael R Levitt,1 Joshua W Osbun,1 Manuel J Ferreira,1 Basavaraj V Ghodke,1,2 Louis J Kim1,2 1
Department of Neurological Surgery, Harborview Medical Center, University of Washington, Seattle, Washington, USA 2 Department of Radiology, Harborview Medical Center, University of Washington, Seattle, Washington, USA Correspondence to Dr Louis J Kim, Department of Neurological Surgery, Harborview Medical Center, UW Medicine, 325 9th Ave, Box 359924, Seattle, WA 98104, USA; [email protected] Received 1 December 2013 Revised 27 January 2014 Accepted 31 January 2014 Published Online First 27 February 2014
ABSTRACT Background Blood blister type aneurysms (BBAs) and pseudoaneurysms create a unique treatment challenge. Despite many advances in open surgical and endovascular techniques, this subset of patients retains relatively high rates of morbidity and mortality. Recently, BBAs have been treated with flow-diverting stents such as the Pipeline Embolization Device (PED) with overall positive results. Methods Four patients presented with dissecting internal carotid artery (ICA) aneurysms treated with the PED (two BBAs presenting with subarachnoid hemorrhage (SAH), two pseudoaneurysms after injury during endoscopic trans-sphenoidal tumor surgery). Results Three patients had a successful angiographic and neurological outcome. One patient with a BBA re-ruptured during initial PED placement, again in the postoperative period, and later died. Primary PED treatment involved telescoping stents in two patients and coil embolization supplementation in one patient. Conclusions The PED should be used selectively in the setting of acute SAH. Dual antiplatelet therapy can complicate hydrocephalus management, and the lack of immediate aneurysm occlusion creates the risk of shortterm re-rupture. PED treatment for iatrogenic ICA pseudoaneurysms can provide a good angiographic and neurological outcome.
INTRODUCTION
To cite: Nerva JD, Morton RP, Levitt MR, et al. J NeuroIntervent Surg 2015;7:210–216. 210
The Pipeline Embolization Device (PED) (ev3, Irvine, California, USA) is a flow-diverting stent (FDS) designed for the treatment of intracranial aneurysms. FDSs redirect blood flow to promote stasis and delayed thrombosis within the aneurysm and reconstruction of the parent artery. In contrast to coil embolization and microsurgical approaches, the aneurysm is not immediately occluded, but rather the FDS reduces flow into the aneurysm promoting thrombosis and eventual endothelialization.1 FDSs require dual antiplatelet therapy until endothelialization occurs in order to minimize thromboembolic complications. As such, the use of the PED in acute subarachnoid hemorrhage (SAH) is controversial.2 3 In the setting of acute SAH, FDSs have been used for aneurysms with difficult morphologies, including blood blister type aneurysms (BBAs) and dissecting aneurysms.2–9 BBAs are small broad-based lesions typically occurring at non-branching sites of the supraclinoid internal carotid artery (ICA).10 11 They account for
0.3–1.7% of ICA aneurysms10–12 and 2.2% of SAH from a ruptured ICA aneurysm.13 Histologically, BBAs show focal arterial wall defects of the internal elastic lamina and media, which leaves a thin layer of fibrous tissue and adventitia protecting the defect, similar to pseudoaneurysms.4 14 The exact pathogenesis is unknown, but focal arterial dissections and penetrating ulcers from atherosclerosis have been implicated.13 15 Numerous surgical and endovascular treatment strategies have been employed, but BBAs remain challenging to treat due to their small size, broad-base and thin fragile walls.2 16 These anatomical features, in combination with a potentially malignant course defined by rapid growth with a high risk of perioperative rupture, further complicate treatment. ICA pseudoaneurysms from iatrogenic injury during endoscopic trans-sphenoidal surgery can result from local dissections and direct injury to the ICA. They are similar to BBAs histologically (including focal artery laceration), geographically (occurring at non-branching sites of the ICA) and in the possibility for rapid enlargement and rupture. In one trans-sphenoidal surgical series, pseudoaneurysms accounted for 3 of 21 vascular injuries in 1800 patients.17 These pseudoaneurysms are typically seen immediately on angiography after intraoperative arterial bleeding, but may also develop in a delayed fashion from a postoperative focal arterial stenosis.17 18 They may also occur in cases without intraoperative arterial hemorrhage, from denuding of the vessel during tumor resection.19 Endovascular techniques have been employed more recently to treat iatrogenic ICA pseudoaneurysms, and the major risks of treatment are due to thin fragile pseudoaneurysm walls and rapid enlargement and recurrence after treatment.20 21 As such, iatrogenic ICA pseudoaneurysms may pose similar intraoperative and perioperative risks to BBAs. Amenta et al22 reported the first case of PED placement for treatment of an ICA pseudoaneurysm from endoscopic sinus surgery. Parent artery reconstruction with FDS has not been reported for the treatment of iatrogenic ICA pseudoaneurysms after endoscopic trans-sphenoidal tumor surgery, where the major difference is the intracranial surgical manipulations that occur during this type of procedure. This has significant implications related to dual antiplatelet therapy. This report highlights PED use in the treatment of these complex aneurysm subtypes of the ICA,
Nerva JD, et al. J NeuroIntervent Surg 2015;7:210–216. doi:10.1136/neurintsurg-2013-011047
Downloaded from http://jnis.bmj.com/ on June 21, 2015 - Published by group.bmj.com
Hemorrhagic stroke with two cases of ruptured BBAs and two cases of iatrogenic pseudoaneurysms.
METHODS All patients were treated at our medical center after review by our multidisciplinary team, which includes endovascular neurosurgeons and interventional neuroradiologists. The cases were retrospectively reviewed. The two patients with BBA presented with SAH and the two patients with pseudoaneurysms occurred after injury during endoscopic trans-sphenoidal tumor surgery (table 1). Open surgical treatment with surgical bypass and trapping and endovascular treatment modalities were discussed with the patients and/ or their families. All cases were reviewed by providers with expertise in open surgical and endovascular management. Based on these discussions and careful consideration of the potential risks and benefits of each modality, endovascular treatment with the PED was elected. Patients were loaded with aspirin 325 mg and clopidogrel 75 mg at least 24 h prior to PED placement. Platelet reactivity testing was performed before the procedure using the VerifyNow point-of care platelet assay (Accumetrics, San Diego, California, USA) which measures the degree of platelet inhibition by aspirin and clopidogrel. Adequate inhibition was defined as
