Li Mei Lin

Immediate procedural outcomes in 44 consecutive Pipeline Flex cases: the first North American single-center series

Background Flow diversion is an established technique for treatment of cerebral aneurysms. The Pipeline embolization device (PED) is the only FDA-approved flow diverting stent in the USA. A second-generation device, PED Flex, has recently been released with modifications to the delivery system. Published reports of experience with this new device are limited. Objective To describe the initial outcomes from the first North American series using the PED Flex—a single-center experience of 44 cases. Methods All patients consecutively treated with the PED Flex embolization device from February 2015 through April 2015 were included in the study. Data were collected for patient demographics, aneurysm characteristics, technical procedural details, and early outcomes. Results PED Flex treatment was attempted in 42 patients (mean 56.6±2.0 years) with 44 aneurysms (mean size 6.5±0.6 mm), 41/44 (93%) of which were anterior circulation and 3/44 (7%) were posterior circulation. PED Flex was successfully implanted in 43/44 cases (98%). A single device was used in 41/43 cases (95%), with a mean of 1.07±0.05 devices implanted per case. Resheathing was performed in 4/44 cases (9%). Mean postprocedure hospital length of stay was 1.3±0.2 days. One significant neurological complication (2.3%) occurred, which was a stroke in a patient non-compliant with the prescribed antiplatelet regimen. Conclusions Pipeline Flex is a second-generation flow diverter with enhanced features compared with the first-generation PED. These modifications allow for more reliable deployment with continued improvements in procedural safety.

P2Y12 hyporesponse (PRU>200) is not associated with increased thromboembolic complications in anterior circulation Pipeline

Introduction Recent reports suggest that thromboembolic complications are associated with Pipeline embolization device (PED) placement cluster in P2Y12 hyporesponders. Objective To evaluate the role of P2Y12 hyporesponse in PED placement by retrospectively reviewing a single-center series of patients. Methods We retrospectively reviewed an institutional review board-approved database of patients with an aneurysm at a single institution and identified all patients with a measured P2Y12 reaction unit (PRU)>200 who had undergone anterior circulation PED placement. Events such as transient ischemic attack, stroke, and hemorrhage were identified as well as demographic and procedural details. Results Fifty-two patients with a PRU >200 had undergone anterior circulation PED placement. Four patients had prior subarachnoid hemorrhage (SAH) (8%) and 11 aneurysms (21%) had been previously treated. The average aneurysm size was 7.6 mm (±6.2). PED thrombosis occurred intraprocedurally in three patients, none of whom developed neurological deficits after abciximab administration. Treatment of all patients was successful and 48 procedures (92%) had no complications. One patient had a major stroke (2%) with permanent hemiparesis. There were three minor complications (6%): one minor stroke with a visual field cut, one 10 cc intracranial hemorrhage with transient left lower extremity weakness, and one transient neurological deficit not verified by imaging. No deaths or cases of SAH occurred. Conclusions P2Y12 hyporesponse (PRU>200) is not associated with increased periprocedural complications in a contemporary series of patients undergoing anterior circulation PED placement. Titration of antiplatelet medications to P2Y12 >200 remains unindicated and may increase the risk of hemorrhagic complications.

Intra-DIC (distal intracranial catheter) deployment of the Pipeline embolization device: a novel rescue strategy for failed device expansion

Background The Pipeline embolization device (PED) is a braided flow diverter that requires a combination of meticulous maneuvers to assure proper device opening and expansion. Mechanical, anatomical, or technical challenges can result in a partially deployed PED with failed expansion. Objective To present a new alternative method of PED deployment using the Navien distal intracranial catheter (DIC) as a salvage maneuver for cases where PED opening fails with standard techniques. Methods We retrospectively reviewed a prospective, single-center aneurysm database to identify all patients who underwent endovascular treatment of intracranial aneurysms using the PED with the Navien distal intracranial catheter access platform. Cases requiring PED deployment within the Navien catheter were reviewed. Data was collected for patient demographics, aneurysm characteristics, and technical details of the interventional procedure. Results Eleven PED neurointerventions requiring intra-Navien PED deployment to fully open the PED were identified. Mean patient age was 55.5±9.9 years (range 37–76 years). Mean aneurysm size was 12.5 mm±4.9 mm (range 2–42 mm). All aneurysms were located in the anterior circulation (anterior cerebral artery, n=1; supraclinoid, n=1; ophthalmic/paraophthalmic, n=6; cavernous, n=3; petrocervical, n=1). Mean fluoroscopy time was 67.1±20.5 min. The intra-Navien technique was used to open the proximal PED (n=7) and the mid-portion (n=4). Post-processing of the PED with a balloon was used in six cases. Conclusions When a partially deployed PED remains constrained despite exhaustion of standard maneuvers to facilitate opening, the technique of intra-Navien PED deployment is a valuable rescue strategy. This new alternative method of PED deployment can be used to open a stretched device with successful completion of the PED implantation.

Endovascular flow diversion for treatment of anterior communicating artery region cerebral aneurysms: a single-center cohort of 50 cases

Background Flow diversion represents a novel but definitive treatment for recurrent and difficult-to-coil aneurysms of the anterior communicating artery (ACoA) region, of which reports are limited. Objective To determine the effectiveness of the Pipeline embolization device (PED) in treating aneurysms in the ACoA region. Methods We retrospectively reviewed an IRB-approved database of patients with an aneurysm at a single institution for patients with ACoA or A1–A2 aneurysms treated with PED. Data analyzed included demographics, aneurysm characteristics, procedural details, follow-up results, and outcomes. Results A total of 50 procedures were performed on 41 patients, including seven patients who underwent bilateral ‘H-pipe’ PED placement. The average age was 56 years and 46% of the patients were female. The average aneurysm size was 4.5 mm, and two large (>10 mm) aneurysms were treated. The vessel of origin was either the ACoA (26 aneurysms, 63%) or the A1–A2 junction (15 aneurysms, 37%). Eighteen patients (44%) had prior subarachnoid hemorrhage and 20 had previously been treated either with clipping (6 aneurysms, 15%) or coiling (14 aneurysms, 34%). Procedural success was achieved in 48/50 cases (96%) and two cases were aborted. Coils were deployed adjunctively in two cases (4%). Procedural outcomes included no deaths, one major ischemic stroke (2%), and two patients with intracranial hemorrhage (4%). Complete aneurysm occlusion was achieved in 81% of patients at 6 months and 85% of patients at last follow-up digital subtraction angiography. Conclusions The PED can be used safely and effectively in the treatment of aneurysms of the ACoA region. This represents a good alternative treatment option to microsurgical clipping and endovascular coiling.

Cerebral aneurysm treatment: modern neurovascular techniques

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years.

Small Aneurysms Account for the Majority and Increasing Percentage of Aneurysmal Subarachnoid Hemorrhage: A 25-Year, Single Institution Study

BACKGROUND Prospective studies of unruptured aneurysms have shown very low rates of rupture for small aneurysms (<10 mm) and suggested that the risk of treatment outweighs benefit. However, common clinical practice shows that patients with aneurysmal subarachnoid hemorrhage (aSAH) frequently have small aneurysms. OBJECTIVE To investigate trends in size and location of ruptured aneurysms over a 25-yr period. METHODS A prospective, Institutional Review Board-approved database of all patients presenting to our institution with aSAH from 1991 to 2016 was analyzed. Cerebral angiography identified the source of hemorrhage. Patients with nonaneurysmal etiologies were excluded. RESULTS Complete data were available for 1306/1562 patients (84%) with aSAH from 1991 to 2016. The average age was 53 yr and 72% of patients were female. The average size of ruptured aneurysms over 25 yr was 8.0 mm. The average size of ruptured aneurysms decreased steadily with each 5-yr interval from 10.1 mm (1991-1996) to 6.6 mm (2012-2016; P < .001). Overall, very small aneurysms (<5 mm) were responsible for aSAH in 41% of patients. The percentage of very small ruptured aneurysms rose from 29% during the initial 5-yr period (1991-1996) to 50% in the most recent period. Likewise, the percentage of ruptured aneurysms that were 5 to 9 mm rose from 26% to 34% (P < .001). In the past 5 yr, aneurysms <10 mm accounted for 84% of aSAH. Vessel of origin (P = .097) and aneurysm location (P = .322) did not vary with time. CONCLUSION Ruptured small and very small aneurysms represent a majority and increasing share of aSAH. Identification and prophylactic treatment of these aneurysms remains an important clinical role for cerebrovascular neurosurgery.

Declining complication rates with flow diversion of anterior circulation aneurysms after introduction of the Pipeline Flex: analysis of a single-institution series of 568 cases

OBJECTIVEThe second-generation Pipeline embolization device (PED), Flex, has several design upgrades, including improved opening and the ability to be resheathed, in comparison with the original device (PED classic). The authors hypothesized that Flex is associated with a lower rate of major complications.METHODSA prospective, IRB-approved, single-institution database was analyzed for all patients with anterior circulation aneurysms treated by flow diversion. The PED classic was used from August 2011 to January 2015, and the Pipeline Flex has been used since February 2015.RESULTSA total of 568 PED procedures (252 classic and 316 Flex) were performed for anterior circulation aneurysms. The average aneurysm size was 6.8 mm. Patients undergoing treatment with the Flex device had smaller aneurysms (p = 0.006) and were more likely to have undergone previous treatments (p = 0.001). Most aneurysms originated along the internal carotid artery (89% classic and 75% Flex) but there were more anterior cerebral artery (18%) and middle cerebral artery (7%) deployments with Flex (p = 0.001). Procedural success was achieved in 96% of classic and 98% of Flex cases (p = 0.078). Major morbidity or death occurred in 3.5% of cases overall: 5.6% of classic cases, and 1.9% of Flex cases (p = 0.019). On multivariate logistic regression, predictors of major complications were in situ thrombosis (OR 4.3, p = 0.006), classic as opposed to Flex device (OR 3.7, p = 0.008), and device deployment in the anterior cerebral artery or middle cerebral artery as opposed to the internal carotid artery (OR 3.5, p = 0.034).CONCLUSIONSFlow diversion of anterior circulation cerebral aneurysms is associated with an overall low rate of major complications. The complication rate is significantly lower since the introduction of the second-generation PED (Flex).

Use of a next-generation multi-durometer long guide sheath for triaxial access in flow diversion: experience in 95 consecutive cases

Background Intracranial access techniques in modern neurointerventions have shifted towards more robust access platforms. The long guide sheath is one of the building blocks of triaxial systems used in intracranial embolizations. Here we present our experience with the AXS Infinity LS long sheath in the triaxial platform for the implantation of the Pipeline embolization device (PED). Methods We retrospectively identified patients who underwent PED Flex treatment with the AXS Infinity LS at a single institution. Procedural data collected included parent artery tortuosity, patient demographics, vasodilator use, aneurysm characteristics, equipment utilized, and catheter-related complications. Results A total of 95 cases were completed using the AXS Infinity LS for the triaxial platform foundation in PED Flex treatment of cerebral aneurysms. Mean patient age was 56.2±12.2 years (range 21–86). Average aneurysm size was 6.9±6.2 mm (range 1–38). There were 89 anterior circulation cases (94%) and 6 posterior circulation cases (6%). Significant cervical ICA tortuosity was present in 11/89 (12%) and moderate to severe cavernous ICA tortuosity was present in 29/89 (33%). Mean fluoroscopy time was 40.0±19.8 min. In 14/95 cases (15%), vasospasm prophylaxis or treatment with intra-arterial verapamil infusion was performed. Catheter access-related complications included asymptomatic iatrogenic dissection in one case (1%) from the distal intracranial catheter and groin hematoma in one case (1%). No parent vessel wall abnormalities were visualized in the region of the Infinity long sheath on final control angiography in all 95 cases. Conclusion The AXS Infinity LS is the newest long guide sheath available for modern neurointerventional procedures. We have shown its utility in augmenting the triaxial access platform in PED Flex cases by providing enhanced distal tip trackability with added support in the aortic arch and proximal great vessels.

Use of the 0.027-inch VIA microcatheter for delivery of Pipeline Flex: a technical note

Background The Pipeline Embolization Device (PED; Medtronic Neurovascular, Irvine, California, USA) is designed for delivery through a 0.027″ microcatheter. Challenges with the second-generation PED Flex include limited support from the Marksman microcatheter for consistent resheathing and transmission of push forces for device delivery. The VIA27 (Sequent Medical/MicroVention Terumo, Tustin, California, USA) is an alternative 0.027″ microcatheter originally designed for intrasaccular flow diverter delivery. Here we describe our experience with the VIA27 in the delivery of PED Flex. Methods We retrospectively identified patients who underwent PED Flex treatment with the VIA27 microcatheter at our institution. Patient demographics, aneurysm characteristics, equipment utilized, and procedural details were documented. Results A total of 127 cases were completed using the VIA27 microcatheter for PED Flex implantation. Mean patient age was 56.8±12.4 years (range 21–86 years). All but one of the cases were treatments for intracranial aneurysms. Average aneurysm size was 6.5±6 mm (range 2–38 mm). Of the 127 cases, 120 (95%) were anterior circulation cases and 7 (6%) were posterior circulation cases. Significant cervical internal carotid artery (ICA) tortuosity was present in 33/120 cases (28%). Moderate to severe cavernous ICA tortuosity was present in 54/120 cases (45%). Mean fluoroscopy time was 34.1±22.7 min. Large diameter PED devices (4.5–5 mm) were used in 42/127 cases (33%). Balloon post-processing of the PED was used in 15/127 cases (12%) to improve vessel wall apposition of the PED. Conclusions The VIA27 is a microcatheter capable of successful PED Flex delivery in neurointervention. We have shown its utility in enhancing both resheathing and push for optimal PED Flex implantation. The VIA27 microcatheter may be a useful and safe adjunct to the traditional Marksman microcatheter in PED Flex treatment of the cerebrovasculature.

Shifting Treatment Paradigms for Ruptured Aneurysms from Open Surgery to Endovascular Therapy Over 25 Years

BACKGROUND Since the introduction of Gugliemi detachable coils in the early 1990s, major clinical studies have supported an increasing role for coil embolization of ruptured aneurysms. We assessed aneurysm location and treatment modality in aneurysmal subarachnoid hemorrhage (aSAH) over the past 25 years. METHODS A prospective, institutional review board-approved aneurysm database was screened for patients presenting with aSAH from 1991 to 2016. Microsurgical and endovascular capabilities were present throughout. All patients underwent cerebral angiography prior to treatment. RESULTS Data were available for 1306/1562 patients (83.6%) presenting with aSAH from 1991-2016. 72% were female, with average age 52.8 years, and average aneurysm size 8.0 mm. The most common vessel of origin was the anterior cerebral artery (37.3%), internal carotid artery (33.3%), and middle cerebral artery (14.6%). Posterior circulation accounted for 14.8% of the aneurysms. Open surgery was performed for 72.4% of aneurysms, endovascular treatment for 22.0%, and 5.7% were not treated. There was an increase in aneurysms treated by endovascular methods over 5-year intervals: 3.0% (1991-1996), 13.4% (1997-2001), 17.2% (2002-2006), 24.3% (2007-2011), and 41.9% (2012-2016). Posterior circulation aneurysms led this trend, increasing from 9.1% endovascular to 71.4%. Endovascular treatment increased from 2.9% and 1.4% of anterior cerebral artery and internal carotid artery aneurysms to 39.6% and 40.7%, respectively, in the most recent 5-year interval. By comparison, endovascular methods remained less commonly used for middle cerebral artery aneurysms (0% initially, now 22.0%). CONCLUSIONS Endovascular treatment of ruptured intracranial aneurysms has steadily increased over the past 25 years at our major academic institution. This is consistent with positive data from clinical trials, advances in endovascular technology, and increasing experience of endovascular specialists.