Stavropoula Tjoumakaris

Off-label uses of the Pipeline embolization device: a review of the literature

The Pipeline embolization device (PED) is the most widely used flow diverter in endovascular neurosurgery. In 2011, the device received FDA approval for the treatment of large and giant aneurysms in the internal carotid artery extending from the petrous to the superior hypophyseal segments. However, as popularity of the device grew and neurosurgeons gained more experience, its use has extended to several other indications. Some of these off-label uses include previously treated aneurysms, acutely ruptured aneurysms, small aneurysms, distal circulation aneurysms, posterior circulation aneurysms, fusiform aneurysms, dissecting aneurysms, pseudoaneurysms, and even carotid-cavernous fistulas. The authors present a literature review of the safety and efficacy of the PED in these off-label uses.

Patency of the posterior communicating artery following treatment with the Pipeline Embolization Device

OBJECTIVE The Pipeline Embolization Device (PED) has become an effective treatment strategy for some cerebral aneurysms. Concerns regarding the patency of branch arteries have been raised. The objective of this study was to assess the patency of the posterior communicating artery (PCoA) following treatment of PCoA aneurysms using the PED. METHODS All patients with PCoA aneurysms treated with the PED who had angiographic follow-up were retrospectively identified. The patency of the PCoA at follow-up was evaluated by 2 authors who were not involved in the intervention. Univariate and multivariate analyses were performed to identify factors associated with the following: 1) PCoA patency versus no or diminished flow, and 2) PCoA patency and diminished flow versus PCoA occlusion. RESULTS Thirty patients with an angiographic follow-up of 6 months were included. Aneurysm obliteration was achieved in 25 patients (83.3%). The PCoA was patent in 7 patients (23.3%), had diminished flow in 7 patients (23.3%), and was occluded in 16 patients (53.3%). In the univariate analysis of outcome, there was a trend for aneurysms with incomplete occlusion, aneurysms not previously treated, those with presence of a fetal PCoA, and those with an artery coming from the aneurysm to have higher odds of the PCoA remaining patent. In univariate and multivariate analyses of factors associated with outcome, fetal PCoA and presence of an artery coming from the aneurysm were associated with the PCoA remaining open with or without diminished flow. No patients had symptoms related to PCoA occlusion. CONCLUSIONS Occlusion and diminished flow through the PCoA is common following PED treatment of PCoA aneurysms. However, it is clinically insignificant in most cases.

Endovascular Management of Intracranial Aneurysms

Data from our clinical series and others supports the idea that endovascular coil embolization is a reliable form of treatment for both ruptured and unruptured cerebral aneurysms. This form of treatment appears from preliminary data to be protective against subarachnoid hemorrhage. Although not likely to replace open surgery, the continued advancements in technology and supportive clinical data will allow endovascular therapy to become a more durable mode of treatment.

Anesthesia Technique and Outcomes of Mechanical Thrombectomy in Patients With Acute Ischemic Stroke.

Background and Purpose— The impact of anesthesia technique on the outcomes of mechanical thrombectomy for acute ischemic stroke remains an issue of debate. We investigated the association of general anesthesia with outcomes in patients undergoing mechanical thrombectomy for ischemic stroke. Methods— We performed a cohort study involving patients undergoing mechanical thrombectomy for ischemic stroke from 2009 to 2013, who were registered in the New York Statewide Planning and Research Cooperative System database. An instrumental variable (hospital rate of general anesthesia) analysis was used to simulate the effects of randomization and investigate the association of anesthesia technique with case-fatality and length of stay. Results— Among 1174 patients, 441 (37.6%) underwent general anesthesia and 733 (62.4%) underwent conscious sedation. Using an instrumental variable analysis, we identified that general anesthesia was associated with a 6.4% increased case-fatality (95% confidence interval, 1.9%–11.0%) and 8.4 days longer length of stay (95% confidence interval, 2.9–14.0) in comparison to conscious sedation. This corresponded to 15 patients needing to be treated with conscious sedation to prevent 1 death. Our results were robust in sensitivity analysis with mixed effects regression and propensity score–adjusted regression models. Conclusions— Using a comprehensive all-payer cohort of acute ischemic stroke patients undergoing mechanical thrombectomy in New York State, we identified an association of general anesthesia with increased case-fatality and length of stay. These considerations should be taken into account when standardizing acute stroke care.

Comparison of non–stent retriever and stent retriever mechanical thrombectomy devices for the endovascular treatment of acute ischemic stroke

OBJECTIVE Mechanical thrombectomy is standard of care for the treatment of acute ischemic stroke. However, limited data are available from assessment of outcomes of FDA-approved devices. The objective of this study is to compare clinical outcomes, efficacy, and safety of non-stent retriever and stent retriever thrombectomy devices. METHODS Between January 2008 and June 2014, 166 patients treated at Jefferson Hospital for Neuroscience for acute ischemic stroke with mechanical thrombectomy using Merci, Penumbra, Solitaire, or Trevo devices were retrospectively reviewed. Primary outcomes included 90-day modified Rankin Scale (mRS) score, recanalization rate (thrombolysis in cerebral infarction [TICI score]), and incidence of symptomatic intracranial hemorrhages (ICHs). Univariate analysis and multivariate logistic regression determined predictors of mRS Score 3-6, mortality, and TICI Score 3. RESULTS A total of 99 patients were treated with non-stent retriever devices (Merci and Penumbra) and 67 with stent retrievers (Solitaire and Trevo). Stent retrievers yielded lower 90-day NIH Stroke Scale scores and higher rates of 90-day mRS scores ≤ 2 (22.54% [non-stent retriever] vs 61.67% [stent retriever]; p < 0.001), TICI Score 2b-3 recanalization rates (79.80% [non-stent retriever] vs 97.01% [stent retriever]; p < 0.001), percentage of parenchyma salvaged, and discharge rates to home/rehabilitation. The overall incidence of ICH was also significantly lower (40.40% [non-stent retriever] vs 13.43% [stent retriever]; p = 0.002), with a trend toward lower 90-day mortality. Use of non-stent retriever devices was an independent predictor of mRS Scores 3-6 (p = 0.002), while use of stent retrievers was an independent predictor of TICI Score 3 (p < 0.001). CONCLUSIONS Stent retriever mechanical thrombectomy devices achieve higher recanalization rates than non-stent retriever devices in acute ischemic stroke with improved clinical and radiographic outcomes and safety.

Clipping of previously coiled cerebral aneurysms: efficacy, safety, and predictors in a cohort of 111 patients

OBJECTIVE With the increasing number of aneurysms treated with endovascular coiling, more recurrences are being encountered. The aim of this study was to evaluate the efficacy and safety of microsurgical clipping in the treatment of recurrent, previously coiled cerebral aneurysms and to identify risk factors that can affect the outcomes of this procedure. METHODS One hundred eleven patients with recurrent aneurysms whose lesions were managed by surgical clipping between January 2002 and October 2014 were identified. The rates of aneurysm occlusion, retreatment, complications, and good clinical outcome were retrospectively determined. Univariate and multivariate logistic regressions were performed to identify factors associated with these outcomes. RESULTS The mean patient age was 50.5 years, the mean aneurysm size was 7 mm, and 97.3% of aneurysms were located in the anterior circulation. The mean follow-up was 22 months. Complete aneurysm occlusion, as assessed by intraoperative angiography, was achieved in 97.3% of aneurysms (108 of 111 patients). Among patients, 1.8% (2 of 111 patients) had a recurrence after clipping. Retreatment was required in 4.5% of patients (5 of 111) after clipping. Major complications were observed in 8% of patients and mortality in 2.7%. Ninety percent of patients had a good clinical outcome. Aneurysm size (OR 1.4, 95% CI 1.08-1.7; p = 0.009) and location in the posterior circulation were significantly associated with higher complications. All 3 patients who had coil extraction experienced a postoperative stroke. Aneurysm size (OR 1.2, 95% CI 1.02-1.45; p = 0.025) and higher number of interventions prior to clipping (OR 5.3, 95% CI 1.3-21.4; p = 0.019) were significant predictors of poor outcome. An aneurysm size > 7 mm was a significant predictor of incomplete obliteration and retreatment (p = 0.018). CONCLUSIONS Surgical clipping is safe and effective in treating recurrent, previously coiled cerebral aneurysms. Aneurysm size, location, and number of previous coiling procedures are important factors to consider in the management of these aneurysms.

Matched Comparison of Flow Diversion and Coiling in Small, Noncomplex Intracranial Aneurysms

BACKGROUNDnFlow diversion is typically reserved for large, giant, or morphologically complex aneurysms. Coiling remains a first-line treatment for small, morphologically simple aneurysms.nnnOBJECTIVEnTo compare coiling and flow diversion in small, uncomplicated intracranial aneurysms (typically amenable to coiling).nnnMETHODSnForty patients treated with thexa0pipelinexa0embolization device (PED) for small (<10 mm), morphologically simple aneurysms that would have also been amenable to coiling were identified. These patients were matched in a 1:1 fashion with 40 patients with comparable aneurysms treated with coiling. Matching was based on age, gender, aneurysm size, and aneurysm morphology.nnnRESULTSnThe 2 groups were comparable with regard to baseline characteristics including age, gender, and aneurysm size. The complication rate did not differ between the 2 groups (2.5% with coiling vs 5% with PED; P = .6). Multivariate analysis did not identify any predictor of complications. Complete occlusion (100%) at follow-up was significantly higher in patients treated with PED (70%) than coiling (47.5%, P = .04). In multivariate analysis, treatment with PED predicted aneurysm obliteration ( P = .04). A significantly higher proportion of coiled patients (32.5%) required retreatment compared with flow diversion (5%, P = .003). In multivariate analysis, coiling predicted retreatment ( P = .006). All patients achieved a favorable outcome (modified Rankin Scale: 0-2) regardless of group.nnnCONCLUSIONnThis matched analysis suggests that flow diversion provides higher occlusion rates, lower retreatment rates, and no additional morbidity compared with coiling in small, simple aneurysms amenable to both techniques. These results suggest a potential benefit for flow diversion over coiling even in small, uncomplicated aneurysms.

The impact of hybrid neurosurgeons on the outcomes of endovascular coiling for unruptured cerebral aneurysms

OBJECTIVE The impact of combined practices on the outcomes of unruptured cerebral aneurysm coiling remains an issue of debate. The authors investigated the association of combined open and endovascular expertise with the outcomes of unruptured cerebral aneurysm coiling. METHODS The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who underwent endovascular coiling for unruptured cerebral aneurysms between 2007 and 2012. To control for confounding, the authors used propensity score conditioning, with mixed effects to account for clustering at the hospital referral region level. RESULTS During the study period, there were 11,716 patients who underwent endovascular coiling for unruptured cerebral aneurysms and met the inclusion criteria. Of these, 1186 (10.1%) underwent treatment performed by hybrid neurosurgeons, and 10,530 (89.9%) by proceduralists who performed only endovascular coiling. Multivariable regression analysis with propensity score adjustment demonstrated a lack of association of combined practice with 1-year postoperative mortality (OR 0.84; 95% CI 0.58-1.23), discharge to rehabilitation (OR 1.0; 95% CI 0.66-1.51), 30-day readmission rate (OR 1.07; 95% CI 0.83-1.38), and length of stay (adjusted difference, 0.41; 95% CI -0.26 to 1.09). Higher procedural volume was independently associated with improved outcomes. CONCLUSIONS In a cohort of Medicare patients, the authors did not demonstrate a difference in mortality, discharge to rehabilitation, readmission rate, and LOS between hybrid neurosurgeons and proceduralists performing only endovascular coiling.

Flow diversion with the pipeline embolization device for patients with intracranial aneurysms and antiplatelet therapy: A systematic literature review

Flow diversion with the Pipeline Embolization Device (PED) is reported as a safe and efficient treatment for patients with intracranial aneurysms; however, literature discussing the antiplatelet (APT) regimen used before and after the PED is limited. Our aim was to systematically review and summarize available data regarding the APT regimen and the platelet function test (PFT) that was used. We also sought to provide an overview of the aneurysm morphologies and adverse event rates associated with the PED use. This systematic review was conducted according to the PRISMA statement and eligible studies were identified through search of the PubMed and Cochrane databases. We reviewed 28 studies, involving 1556 patients that underwent aneurysm treatment with the PED. The preprocedural aspirin (ASA) 300- 325mg (2-14days) combined with clopidogrel 75mg (3 to >10days) were used as a treatment strategy in 61.7% of patients and ASA 81mg with clopidogrel 75mg for 5-10days for 27%. Patients who received low versus high dose pre-PED ASA, were at less risk for a hemorrhagic event (0.7% versus 3.3%, p=0.053); however no statistical significance was reached. There was also lack of relationship between patients that received low versus high preprocedural ASA in terms of thromboembolic events. Regarding postprocedural APT, ASA (>6months) and clopidogrel (3- 12 months) was the regimen of choice for 93% of patients. Most studies conducted at least one PFT, most common being the VerifyNow. The most frequently reported target P2Y12 Reaction unit (PRU) and Aspirin Reaction Unit (ARU) values were <230 and <550 respectively. There was no statistically demonstrable difference in regards to thrombotic events between centers that conducted at least one PFT and centers that did not test their patients with a PFT. The overall rates of symptomatic thrombotic episodes were 6.6% and hemorrhagic were 3%. The pre- and post-PED APT dose and duration varies across different institutions. More prospective studies are needed to compare the efficacy of different APT agents and reach conclusions regarding use of PFT and platelet reaction values in order to decrease hemorrhagic and thromboembolic complications associated with the PED.

Acute Recanalization of a Partially Thrombosed Large Intracranial Aneurysm

BACKGROUNDnThrombosed large intracranial aneurysms (TLIAs) are not continuously contemplated as stable lesions. Spontaneous recanalization of completely occluded large intracranial aneurysms has been described previously.nnnCASE DESCRIPTIONnWe report a middle-aged patient presenting with agitation, acute headache, visual field defects, and left hemiparesis. A large thrombosed posterior communicating (PCom) artery aneurysm was identified with an infarct at the same arterial territory on neuroimaging studies. Digital subtraction angiography (DSA) performed 1 week later demonstrated complete recanalization of the TLIA. It was treated endovascularly with coils. The patient returned several days later with augmenting headaches due to quadrigeminal system subarachnoid hemorrhage. Repeat DSA showed filling of the coiled aneurysm from the internal carotid artery injection. The PCom artery was catheterized and deconstructed. The patient was discharged to home with no additional neurologic deficits.nnnCONCLUSIONSnTLIAs are insidious vascular lesions. They can cause nerve or vessel damage by a mass effect or through ischemic stroke by emitting emboli into distal vasculature. We advise close periodic radiologic follow-up for TLIAs.