Mark R. Villwock

Significant increases of pituitary tumors and resections from 1993 to 2011

Pituitary tumors comprise 10% to 15% of all diagnosed intracranial tumors; 90% are adenomas. Though benign, significant morbidity via compression of surrounding structures or aberrant hormone secretion can occur. This study investigated rates of pituitary tumor diagnoses and treatment trends from 1993 to 2011.

Early experience with stent retrievers and comparison with previous-generation mechanical thrombectomy devices for acute ischemic stroke

UNLABELLED OBJECT.: There is limited information regarding patient outcomes following interventions for stroke during the window for endovascular therapy. Studies have suggested that recently approved stent retrievers are safer and more effective than earlier-generation thrombectomy devices. The authors compared cases in which the Solitaire-FR device was used to those in which a MERCI or Penumbra device was used. METHODS This study is a single-center retrospective review of 102 consecutive cases of acute stroke in which patients were treated with mechanical thrombectomy devices between 2007 and 2013. Multivariate models, adjusted for confounding factors, were used to investigate functional independence (modified Rankin Scale [mRS] score ≤ 2, and successful reperfusion (thrombolysis in cerebral infarction [TICI] score ≥ 2b). RESULTS Thrombectomy device had a significant impact on functional independence (mRS score ≤ 2) at discharge from the hospital (p = 0.040). Solitaire-FR treatment resulted in significantly more patients being discharged as functionally independent in comparison with MERCI treatment (p = 0.016). A multivariate model found the use of Solitaire-FR to improve the odds of good clinical outcome in comparison with prior-generation devices (OR 6.283, 95% CI 1.785-22.119, p = 0.004). Additionally, the use of Solitaire-FR significantly increased the odds of successful reperfusion (OR 3.247, 95% CI 1.160-9.090, p = 0.025). CONCLUSIONS The stent retriever Solitaire-FR significantly improved the odds of functional independence and successful revascularization of the arterial tree. New interventional technology for stroke continues to mature, but randomized trials are needed to establish the actual benefit to specific patient populations.

Aneurysm embolization grade: a predictive tool for aneurysm recurrence after coil embolization

BackgroundCoil embolization has gained importance in the management of intracranial aneurysms over the past decade. However, the recurrence risk after embolization mandates closer follow-up than surgical clip ligation. Currently, there is no reliable system for predicting aneurysm sac thrombosis. An aneurysm embolization grade (AEG) reported previously by the senior author (EMD) has been proposed as a tool for predicting the durability of aneurysm occlusion based on hemodynamic characteristics. Here, we present our internal validity results.MethodsAEG and Raymond–Roy Occlusion Classification (RROC) scores were prospectively assigned to all aneurysms coiled from June 2008 to June 2011. The prospectively assigned AEG and RROC scores from the cerebral angiograms were collected for data analysis and validity assessment of the AEG system. 110 consecutive patients who had aneurysm coil embolization were included in this study.ResultsThe post-coiling AEG significantly predicted follow-up angiographic filling characteristics. Pairwise comparisons revealed that the follow-up AEG for those initially scored ‘A’ (complete obliteration) was significantly better than the contrast-flow groups. Significant differences were also noted between contrast-stasis and contrast-flow groups. A pairwise comparison between RROC scores demonstrated that only the RROC Type 1 could be used to predict follow-up occlusion durability. Stent placement in wide-neck aneurysms had no effect on initial AEG, RROC, or long-term occlusion durability. Packing density significantly predicted initial AEG and RROC, but had no effect on long-term occlusion.ConclusionsThe AEG system is uniquely based on angiographic filling characteristics of the aneurysm, and this study demonstrated its high predictive value for determining aneurysm sac thrombosis. Assigning an AEG to the aneurysm can guide the neurointerventionalist in discussions with the patient regarding the probability of aneurysm recurrence and potential need for retreatment.

Stenting versus Endarterectomy and the Impact of Ultra-early Revascularization for Emergent Admissions of Carotid Artery Stenosis

BACKGROUND The factors influencing outcomes after emergent admission for symptomatic carotid artery stenosis treated with revascularization by endarterectomy or stenting are yet to be fully elucidated. METHODS We analyzed revascularization of carotid artery stenosis for patients admitted emergently using the Nationwide Inpatient Sample (2008-2011). Admission characteristics, economic measures, in-hospital mortality, and iatrogenic stroke were compared between (1) endarterectomy and stenting, (2) patients with and without cerebral infarction, and (3) ultra-early (within 48 hours of admission) and deferred (up to 2 weeks) intervention. RESULTS 72,797 admissions meeting our inclusion criteria were identified. Factors associated with ultra-early revascularization were male patients, low comorbidity burden, stenosis without infarction, and stenting. Ultra-early intervention significantly decreased cost and length of stay, and stenting for patients without infarction decreased length of stay but increased cost. Patients without infarction treated within 48 hours had significantly lower mortality and iatrogenic stroke rate. Patients with infarction receiving ultra-early revascularization had increased odds of mortality and iatrogenic stroke in comparison with the deferred group. Patients with infarction receiving stenting experienced increased odds of mortality in comparison with those receiving endarterectomy, but there was no significant difference in iatrogenic stroke rate. Recombinant tissue plasminogen activator (rtPA) administration on the day of revascularization greatly increased the odds of iatrogenic stroke and mortality. CONCLUSIONS Larger prospectively randomized trials evaluating the optimum timing of revascularization after emergent admission of carotid artery stenosis seem warranted.

Acute ischaemic stroke outcomes following mechanical thrombectomy in the elderly versus their younger counterpart: a retrospective cohort study

Objectives Many physicians debate the efficacy of mechanical thrombectomy for ischaemic stroke, but most agree that to establish potential benefit, patient selection must be examined further. People >80 years are a growing population of patients with ischaemic stroke but are largely excluded from clinical trials. The benefit of thrombectomy for them may be greatly reduced due to diminishing neuroplasticity and a larger number of medical comorbidities. To address this knowledge gap, we examined clinical and economic outcomes after mechanical thrombectomy in the ischaemic stroke population from the Nationwide Inpatient Sample. Our null hypotheses were that elderly patients (>80 years) would have a similar rate of inpatient mortality in comparison to their younger counterparts and incur a similar economic expense. Design Retrospective cohort study. Setting A 20% stratified sample of US community hospitals within the Nationwide Inpatient Sample. Participants All patients from 2008 to 2010 with a primary diagnosis of ischaemic stroke that received mechanical thrombectomy were included. Primary and secondary outcome measures The primary outcome was inpatient mortality. Secondary outcomes included hospital charges and length of stay. Results Less than 1% of all ischaemic stroke cases (9300) were treated with mechanical thrombectomy. Of these, 18% involved patients over 80 years of age. The odds of inpatient mortality in elderly patients treated with mechanical thrombectomy were approximately twice that of their younger counterparts (OR1.993, p < 0.001). The elderly experienced no significant difference in hospital charges (p=0.105) and length of stay (p=0.498). Conclusions The odds of inpatient mortality after mechanical thrombectomy in patients over 80 years of age were twice that of their younger counterparts. This is consistent with the overall worse prognosis seen in the natural history of this age group. Studies to better identify patients that would benefit from endovascular mechanical thrombectomy may improve outcomes and reduce the gap currently observed in age stratifications.

The Penumbra Coil 400 System for Treatment of Wide-Necked Intracranial Aneurysms: Initial Single-Center Experience

Endovascular treatment of wide-necked intracranial aneurysms frequently requires stent- or balloon-assisted coiling to prevent coil herniation into the parent artery. Provided that coils can be securely deployed within the aneurysm sac, these adjunctive devices and their associated risk can be avoided. The Penumbra 400 Coil (PC-400) has a larger diameter than conventional coils and is constructed completely of metal, a feature that increases the coil stability and may improve its ability to respect the aneurysm neck. The purpose of this study was to examine the frequency of adjunctive stent usage when coiling wide-necked intracranial aneurysms with the PC-400 in comparison with conventional coils. We examined consecutive patients with unruptured wide-necked aneurysms treated at our institution with endovascular coils. Aneurysm characteristics and procedural outcomes were compared between patients treated with PC-400 compared with a control group treated with conventional coils. Thirty-eight patients met criteria for this study. Stent-assisted coiling was required in 34 % fewer cases using PC-400 compared with conventional coils (P = .049). Fewer coils and less length were required with the PC-400 to obtain the same packing densities, occlusion types, and short-term stability. This may reduce treatment cost and prove to be valuable in patients with contraindications to dual antiplatelet therapy.

Mild Exercise Reduces Cerebral Vasospasm After Aneurysm Subarachnoid Hemorrhage: A Retrospective Clinical Study and Correlation with Laboratory Investigation

BACKGROUND Aneurysmal subarachnoid hemorrhage (SAH) is a leading cause of death and disability and is often complicated by cerebral vasospasm (CV). Conventional management to prevent CV includes bedrest; however, inactivity places the patient at risk for nonneurological complications. We investigated the effect of mild exercise after SAH in clinical and laboratory settings. METHODS Clinical: Data from 80 patients with SAH were analyzed retrospectively. After aneurysms were secured, physical therapy was initiated as tolerated. CV and complications were compared by the timing of active physical therapy. Laboratory: 18 Rodents were divided into three groups: (1) control, (2) SAH without exercise, and (3) SAH plus mild exercise. On day 5, brainstems were removed and analyzed for the injury marker inducible nitric oxide synthase (iNOS). RESULTS Clinical: Mild exercise before day 4 significantly lowered the incidence of symptomatic CV compared with the nonexercised group. There was no difference in the incidence of additional complications based upon exercise. Laboratory: Staining for iNOS was significantly higher in the SAH group than the control group, but there was no difference between exercised and nonexercised SAH groups, confirming that exercise did not promote neuronal injury. CONCLUSION Early mobilization significantly reduced clinical CV. The relationship should be studied further in a prospective trial with defined exercise regimens.

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms.

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients ≤55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged ≤55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges:

Trends in mortality following mechanical thrombectomy for the treatment of acute ischemic stroke in the USA

52,779 vs.

Open direct carotid artery access for coiling of an intracranial aneurysm under conscious sedation

101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.