Clinical and angiographic outcomes in patients with intracranial aneurysms treated with the pipeline embolization device: intra-procedural technical difficulties, major morbidity, and neurological mortality decrease significantly with increased operator experience in device deployment and patient management

PURPOSE

Flow diversion constitutes a pivotal advancement in endovascular intracranial aneurysm treatment, but requires development of a new skill set. The aim of this study is to determine whether outcomes after treatment with the Pipeline Embolization Device improve with experience.

METHODS

We retrospectively reviewed all patients with intracranial aneurysms treated with Pipeline at two centers over a 4.5-year period. Baseline patient and aneurysm characteristics, complications, and angiographic outcomes were analyzed.

RESULTS

One hundred forty patients underwent 150 Pipeline procedures to treat 167 intracranial aneurysms during the study period, 109 women, mean age 55.4 years. One hundred twenty-six aneurysms were ICA, mean size 10.2 mm and mean neck 6.4 mm. Intra-procedural technical difficulties were higher during the first 75 procedures compared with the subsequent 75 (13.3 vs 2.7%; p = 0.03), as combined major morbidity and neurological mortality (14.7 vs 4%; p = 0.046). In multivariate regression analysis, increased operator experience with Pipeline remained an independent predictor of intra-procedural technical difficulties (p = 0.02, odds ratio (OR) 0.015, 95% CI 0.0004-0.55) and combined major morbidity and neurological mortality (p = 0.03, OR 0.16, 95% CI 0.03-0.84). At last follow-up, 123 aneurysms were completely occluded (81.5%, mean 24 months). In our cohort, age ≤ 53 years was an independent predictor of complete aneurysm occlusion at last follow-up (p = 0.001, OR 0.92, 95% CI 0.88-0.97). Five aneurysms were retreated (3.3%).

CONCLUSION

The Pipeline embolization device is an effective treatment for intracranial aneurysms. The risk of intra-procedural technical difficulties and combined major morbidity and neurological mortality decreases significantly with increased operator experience in Pipeline deployment and patient management.

A New Protocol for Anticoagulation With Tirofiban During Flow Diversion

BACKGROUND:

Flow diversion is increasingly used to treat intracranial aneurysms. In previous reports, patients were pretreated with aspirin and clopidogrel before the intervention for the prevention of thromboembolic complications.

OBJECTIVE:

To assess the safety and efficacy of a new protocol for anticoagulation using tirofiban during flow diversion.

METHODS:

All patients received a 0.10–μg.kg−1.min−1 maintenance infusion of tirofiban intraoperatively without a loading dose. All patients were loaded with aspirin (325 mg) and clopidogrel (600 mg) just before the procedure or intraoperatively. No patient was pretreated with aspirin or clopidogrel. Thromboembolic and hemorrhagic complications were recorded.

RESULTS:

A total of 46 patients were treated with this protocol. Six patients (13%) had sustained a subarachnoid hemorrhage and were treated with the Pipeline Embolization Device within 24 hours of aneurysm rupture. The mean number of devices was 1.2 ± 0.66; adjunctive coiling was performed in 3 patients (6.5%). There were 2 complications (4.3%), 1 thromboembolic (2.2%) and 1 hemorrhagic (2.2%; monocular vision loss from occlusion of the central retinal artery in 1 patient and a parenchymal hemorrhage managed conservatively in another patient). No patient developed thrombocytopenia or retroperitoneal, gastrointestinal, or genitourinary bleeding. Of 46 patients, 44 (95.7%) had a modified Rankin Scale score of 0 to 2 at their follow-up visit.

CONCLUSION:

A protocol of anticoagulation with tirofiban during flow diversion has an excellent safety profile. This protocol provides a reasonable alternative to pretreatment with aspirin and clopidogrel and is useful in patients with ruptured aneurysms or when the use of a stent is unexpected.

Treatment of ruptured intracranial aneurysms with the pipeline embolization device

BACKGROUND

The pipeline embolization device (PED) has been used for treatment of unruptured aneurysms. Little is known about the use of the PED in ruptured aneurysms.

OBJECTIVE

To assess the safety and efficacy of the PED in ruptured intracranial aneurysms.

METHODS

This is a case series with prospective data collection on 20 patients with freshly ruptured aneurysms who were treated with PED (with or without adjunctive coiling) at 2 cerebrovascular centers. Patients were loaded with aspirin and clopidogrel or received an infusion of tirofiban intraoperatively.

RESULTS

Hunt and Hess grades were I in 7 patients (35%), II in 9 (45%), and III in 4 (20%). The mean duration from hemorrhage to PED placement was 7±7.0 days. A single device was used in all but 1 patient (95%). The procedure was staged in 20%. There was only 1 complication (5%); this was a fatal intraoperative aneurysm dome rupture that occurred during adjunctive coil deployment. Adjunctive coiling was used in 30%. No patient required an invasive procedure after PED placement. Follow-up angiography (mean, 5.3±4.2 months; range, 2-12 months) showed 100% occlusion in 12 (80%) and incomplete occlusion in 3 patients (20%). At latest follow-up, 19 patients achieved a favorable outcome (modified rankin scale 0-2).

CONCLUSION

In our preliminary experience, treatment of ruptured aneurysms with the PED was associated with low complication rates, high occlusion rates, and favorable outcomes. These findings suggest that PED may be a safe and effective option for patients with favorable Hunt and Hess grades and aneurysms difficult to treat with conventional methods.

Prospective Study of Early MRI Appearances following Flow-Diverting Stent Placement for Intracranial Aneurysms

BACKGROUND AND PURPOSE

MR imaging findings of aneurysm enlargement, aneurysm wall enhancement, perianeurysmal edema, and embolic phenomena following deployment of flow-diverting stents may be relevant to those patients who subsequently experience procedure-related intracranial hemorrhage. We sought to document the routine early postoperative MR imaging findings following flow-diverting stent insertion.

MATERIALS AND METHODS

Patients requiring flow-diverting stent placement for treatment or retreatment of cerebral aneurysms were prospectively included in the study during a 26-month period. Early postprocedural MR imaging studies were obtained and compared with preoperative imaging. Patient clinical outcome data were also collected.

RESULTS

There were 34 stent-placement procedures during the study period. Aneurysm mural enhancement and mild new perianeurysmal edema were present in 50% and 14%, respectively. Any DWI lesion was present in 57% of cases. New or possibly new foci of susceptibility effect were found ipsilateral to the stent and not associated with diffusion restriction in 66% of cases. There were 2 cases (6%) of parenchymal hemorrhage and 2 major clinical complications (6%) causing permanent morbidity.

CONCLUSIONS

Asymptomatic aneurysm mural enhancement is frequently seen following flow-diverting stent placement and should not necessarily be interpreted as a sign of impending aneurysm rupture. This finding often persists despite complete aneurysm occlusion. New small brain parenchymal susceptibility foci following stent placement have not previously been reported, to our knowledge, but were common in our series.

Safety and efficacy of the Pipeline Embolization Device in 100 small intracranial aneurysms

OBJECT Flow diverters are increasingly used for treatment of intracranial aneurysms. In most series, the Pipeline Embolization Device (PED) was used for the treatment of large, giant, complex, and fusiform aneurysms. Little is known about the use of the PED in small aneurysms. The purpose of this study was to assess the safety and efficacy of the PED in small aneurysms (≤ 7 mm). METHODS A total of 100 consecutive patients were treated with the PED at the authors' institution between May 2011 and September 2013. Data on procedural safety and efficacy were retrospectively collected. RESULTS The mean aneurysm size was 5.2 ± 1.5 mm. Seven patients (7%) had sustained a subarachnoid hemorrhage. All except 5 aneurysms (95%) arose from the anterior circulation. The number of PEDs used was 1.2 per aneurysm. Symptomatic procedure-related complications occurred in 3 patients (3%): 1 distal parenchymal hemorrhage that was managed conservatively and 2 ischemic events. At the latest follow-up (mean 6.3 months), 54 (72%) aneurysms were completely occluded (100%), 10 (13%) were nearly completely occluded (≥ 90%), and 11 (15%) were incompletely occluded (< 90%). Six aneurysms (8%) required further treatment. Increasing aneurysm size (OR 3.8, 95% CI 0.99-14; p = 0.05) predicted retreatment. All patients achieved a favorable outcome (modified Rankin Scale Score 0-2) at follow-up. CONCLUSIONS In this study, treatment of small aneurysms with the PED was associated with low complication rates and high aneurysm occlusion rates. These findings suggest that the PED is a safe and effective alternative to conventional endovascular techniques for small aneurysms. Randomized trials with long-term follow-up are necessary to determine the optimal treatment that leads to the highest rate of obliteration and the best clinical outcomes.

Periprocedural and mid-term technical and clinical events after flow diversion for intracranial aneurysms

OBJECT

Flow diversion has emerged as a promising treatment alternative for cerebral aneurysms. As a new device, treatment-related events and complications are currently being characterized.

METHODS

Data on 100 consecutive procedures with the intention to use flow diversion were prospectively collected and analyzed retrospectively.

RESULTS

Ninety-five aneurysms were treated in 93 patients during 100 consecutive procedures in which the intention was to treat an intracranial aneurysm with flow diversion. Death occurred in 1% and permanent morbidity in 1%. However, periprocedural technical complications occurred in 35% of the procedures and included proximal device migration in 12%, incomplete device expansion in 9%, catheter-induced vasospasm in 6%, and artery perforation from the wire in 3%. Perioperative clinical events were seen in 28% (thromboembolism and access site complications were the most common, being observed in 6.5% of patients). Worsened extraocular motility was seen in 5.4% and resolved in 4/5 patients. Mean clinical follow-up was 17 months. There were no late clinical or technical issues resulting in permanent deficits, although one patient suffered worsening ataxia. Overall, using very strict angiographic criteria, complete angiographic obliteration was 50% at 6 months and 69% after 1 year.

CONCLUSIONS

Flow diversion for intracranial aneurysms is a safe and effective treatment. Technical and clinical events are common in the perioperative period. Careful perioperative care and proper management of technical and clinical events encountered is key to achieving low morbidity and mortality. Late clinical events can occur but are unlikely to result in permanent complications.

Endovascular treatment of complex aneurysms at the vertebrobasilar junction with flow-diverting stents: initial experience

BACKGROUND

Large or giant complex vertebrobasilar junction aneurysms have a dismal natural history and are often challenging to treat with standard endovascular or neurosurgical techniques.

OBJECTIVE

To report initial experience with endovascular treatment of these aneurysms using flow-diverting stents (FDS).

METHODS

Ten patients with FDS treatment of complex vertebrobasilar junction aneurysms were collected from 4 large cerebrovascular centers. Clinical/angiographic presentation and outcome were retrospectively analyzed.

RESULTS

Of 10 aneurysms, 7 presented with brainstem compression, 2 with ischemia, and 1 with subarachnoid hemorrhage, and 3 were recurrent after stent-assisted treatments. Eight were giant. Morphology was fusiform in 5, fusiform dissecting in 1, and multilobulated saccular in 4. Six were partially thrombosed. In addition to FDS (mean number of devices, 3.9; range, 1-9), contralateral vertebral artery sacrifice and adjunctive coiling were performed in 9 and 5 of the 10 patients, respectively. At follow-up, 5 of 10 were completely occluded, 4 showed minimal residual filling, and 1 was retreated with an additional FDS. Postinterventionally, worsening mass effect and ischemic complications were seen in 2 and 4 of 10, respectively. Clinical outcome was good in 6 (modified Rankin Scale score, 0-2). Four fatalities were related to sequelae of subarachnoid hemorrhage, late FDS thrombosis, progressive mass effect, and delayed intracranial hemorrhage.

CONCLUSION

FDS may be used to treat complex vertebrobasilar junction aneurysms with overall good angiographic outcome. A combined reconstructive/deconstructive approach appears useful to avoid endoleaks. FDS strategies, like other endovascular and neurosurgical approaches to these lesions, are associated with significant risk and therefore should be reserved for those cases in which alternative approaches either are deemed unsafe or are likely to be ineffective.

ABBREVIATIONS

FDS, flow-diverting stentPED, Pipeline Embolization DeviceSAH, subarachnoid hemorrhageVA, vertebral arteryVBJ, vertebrobasilar junction.

Treatment of Blister-Like Aneurysms With the Pipeline Embolization Device

BACKGROUND:

Endovascular vessel reconstruction with the pipeline embolization device (PED) has become common practice. Data on the safety and efficacy of the PED in blister-like aneurysms (BLAs) are limited.

OBJECTIVE:

To retrospectively present our experience with use of the PED in BLAs.

METHODS:

A total of 8 patients harboring 8 BLAs were treated with the PED at our institution between November 2011 and April 2013.

RESULTS:

Aneurysm size was 2.5 mm on average. Five patients had sustained a subarachnoid hemorrhage (SAH), 1 patient presented with sentinel headaches, and in 2 patients the aneurysm was incidentally discovered. Seven aneurysms arose from the ICA and 1 from the basilar artery. Placement of the PED was successful in all 8 patients. There were no procedural or perioperative complications in any of the patients. At the latest follow-up, all 8 patients achieved a favorable outcome (mRS 0-2). Angiographic follow-up was available for 6 patients at a mean time point of 3.9 months. Follow-up angiography showed 100% aneurysm occlusion in 5 patients and marked decrease in aneurysm size in 1 patient.

CONCLUSION:

The findings of this study suggest that the PED may be a safe and effective treatment for BLAs. Given the limitations of other treatment modalities and the challenging nature of BLAs, flow diversion may be a valuable option for these lesions.

Extending the Indications of Flow Diversion to Small, Unruptured, Saccular Aneurysms of the Anterior Circulation

Background and Purpose—

Flow diverters are currently indicated for treatment of large and complex intracranial aneurysms. The purpose of this study was to determine whether the indications of flow diversion can be safely extended to unruptured, small, saccular aneurysms (<10 mm) of the anterior circulation.

Methods—

Forty patients treated with the pipeline embolization device (PED) were matched in a 1:4 fashion with 160 patients treated with stent-assisted coiling based on patient age, sex, aneurysm location, and aneurysm size. Procedural complications, angiographic results, and clinical outcomes were analyzed and compared.

Results—

The rate of periprocedural complications was 5% in the PED group and 3% in the stent-coil group ( P =0.7). In multivariable analysis, increasing age was the only predictor of complications. At follow-up, a higher proportion of aneurysms treated with PED (80%) achieved complete obliteration compared with stent-coiled aneurysms (70%) but the difference did not reach statistical significance ( P =0.2). In multivariable analysis, increasing aneurysm size and aneurysm location were predictors of nonocclusion. The rate of favorable outcome (modified Rankin Scale, 0–2 and modified Rankin Scale, 0–1) was similar in the PED group and the coil group.

Conclusions—

The PED was associated with similar periprocedural risks, clinical outcomes, and angiographic results compared with stent-assisted coiling. These findings suggest that the indications of PED can be safely extended to small intracranial aneurysms that are amenable to conventional endovascular techniques. Larger studies with long-term follow-up are necessary to determine the optimal treatment that leads to the highest rate of obliteration and best clinical outcomes.

Last-recorded P2Y12 reaction units value is strongly associated with thromboembolic and hemorrhagic complications occurring up to 6 months after treatment in patients with cerebral aneurysms treated with the pipeline embolization device

BACKGROUND AND PURPOSE

A recent study identified a preprocedural P2Y12 reaction units value of <60 or >240 as a strong independent predictor of perioperative thromboembolic and hemorrhagic complications after treatment of cerebral aneurysms with the Pipeline Embolization Device. This study aimed to determine whether a last-recorded P2Y12 reaction units value of <60 or >240 predicts thromboembolic and hemorrhagic complications up to 6 months after treatment of cerebral aneurysms with the Pipeline Embolization Device in the same patient cohort.

MATERIALS AND METHODS

We recorded patient and aneurysm characteristics, P2Y12 receptor antagonist administered, P2Y12 reaction units value with VerifyNow, procedural variables, and thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures at our institution during an 8-month period. Complications causing a permanent disabling neurologic deficit or death were considered major. Multivariate regression analysis was performed to identify independent predictors of thromboembolic and hemorrhagic complications.

RESULTS

Forty-four patients underwent 48 Pipeline Embolization Device procedures at our institution during the study period. There were 11 thromboembolic and hemorrhagic complications up to 6 months after treatment in our cohort (22.9%), 5 of which were major (10.4%). A last-recorded P2Y12 reaction units value of <60 or >240 was the only independent predictor of all (P = .002) and major (P = .03) thromboembolic and hemorrhagic complications in our cohort. Most patients (71%) required, on average, 2 adjustments to the dose or type of P2Y12 receptor antagonist to remain within the 60-240 target P2Y12 reaction units range.

CONCLUSIONS

In our cohort, a last-recorded P2Y12 reaction units value of <60 or >240 was the only independent predictor of all and major thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures.

Incidence of microemboli and correlation with platelet inhibition in aneurysmal flow diversion

Flow-diverting stents have been associated with embolic and hemorrhagic complications, but the rate of procedure-related microemboli is unknown. Using transcranial Doppler sonography, we measured the rate of microemboli in 23 patients treated with flow-diverting stents. Patients received preprocedural dual antiplatelet medications and intraprocedural heparinization. Point-of-care platelet reactivity testing was performed before the procedure, and nonresponders (>213 P2Y12/ADP receptor reactivity units) received additional thienopyridine. Transcranial Doppler sonography was performed within 12-24 hours. Microemboli were detected in 3 patients (13%), 2 of whom were initially nonresponders. There was no association between the presence of microemboli and procedural or neurologic complications, aneurysm size, number of stents, or procedure time. Eight procedures (34.8%) required additional thienopyridine for inadequate platelet inhibition, and 3 required further treatment for persistent nonresponse to point-of-care platelet reactivity testing. There were 6 technical and 2 postoperative complications; none were associated with inadequate platelet inhibition or microemboli. The combination of routine point-of-care platelet reactivity testing and postprocedural microembolic monitoring may help identify patients at risk for thromboembolic complications after flow-diverting stents.