Endovascular therapy of wake-up strokes in the modern era of stent retriever thrombectomy.

BACKGROUND: Endovascular treatment of wake-up strokes (WUS) has been previously described, mostly with the use of pharmacological thrombolysis or first generation thrombectomy devices. OBJECTIVE: To describe outcomes of WUS treated with modern endovascular therapy since the Food and Drug Administration approval of stent retrievers, and to identify predictors of good clinical outcome in this population of stroke patients. METHODS: We performed a multicenter retrospective analysis of consecutive patients with WUS who underwent thrombectomy with stent retrievers Trevo (Stryker, Kalamazoo, Michigan, USA) and Solitaire FR (Covidien, Irvine, California, USA), or primary aspiration thrombectomy. We correlated favorable clinical outcomes with demographic, clinical, and technical characteristics. RESULTS: 52 patients were included in this study; 46 (88%) cases were treated with stent retrievers and 6 (12%) were treated with primary aspiration thrombectomy alone. Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b/3) was achieved in 36 (69%) patients. Favorable clinical outcome at 3 months, defined as a modified Rankin Scale score of 0-2, was achieved in 25 (48%) patients. Duration of intervention <30 min and its success, defined as TICI 2b/3 recanalization, were strong predictors of favorable clinical outcome at 90 days (p<0.001 and p<0.0001, respectively). CONCLUSIONS: Our study indicates that endovascular treatment of WUS with stent retrievers and aspiration thrombectomy is safe and effective.

Cost-Effectiveness Analysis of Microscopic and Endoscopic Transsphenoidal Surgery Versus Medical Therapy in the Management of Microprolactinoma in the United States.

BACKGROUND: Although prolactinomas are treated effectively with dopamine agonists, some have proposed curative surgical resection for select cases of microprolactinomas to avoid life-long medical therapy. We performed a cost-effectiveness analysis comparing transsphenoidal surgery (either microsurgical or endoscopic) and medical therapy (either bromocriptine or cabergoline) with decision analysis modeling. METHODS: A 2-armed decision tree was created with TreeAge Pro Suite 2012 to compare upfront transsphenoidal surgery versus medical therapy. The economic perspective was that of the health care third-party payer. On the basis of a literature review, we assigned plausible distributions for costs and utilities to each potential outcome, taking into account medical and surgical costs and complications. Base-case analysis, sensitivity analysis, and Monte Carlo simulations were performed to determine the cost-effectiveness of each strategy at 5-year and 10-year time horizons. RESULTS: In the base-case scenario, microscopic transsphenoidal surgery was the most cost-effective option at 5 years from the time of diagnosis; however, by the 10-year time horizon, endoscopic transsphenoidal surgery became the most cost-effective option. At both time horizons, medical therapy (both bromocriptine and cabergoline) were found to be more costly and less effective than transsphenoidal surgery (i.e., the medical arm was dominated by the surgical arm in this model). Two-way sensitivity analysis demonstrated that endoscopic resection would be the most cost-effective strategy if the cure rate from endoscopic surgery was greater than 90% and the complication rate was less than 1%. Monte Carlo simulation was performed for endoscopic surgery versus microscopic surgery at both time horizons. This analysis produced an incremental cost-effectiveness ratio of $80,235 per quality-adjusted life years at 5 years and $40,737 per quality-adjusted life years at 10 years, implying that with increasing time intervals, endoscopic transsphenoidal surgery is the more cost-effective treatment strategy. CONCLUSIONS: On the basis of the results of our model, transsphenoidal surgical resection of microprolactinomas, either microsurgical or endoscopic, appears to be more cost-effective than life-long medical therapy in young patients with life expectancy greater than 10 years. We caution that surgical resection for microprolactinomas be performed only in select cases by experienced pituitary surgeons at high-volume centers with high biochemical cure rates and low complication rates.

Does the real-time thermal damage estimate allow for estimation of tumor control after MRI-guided laser-induced thermal therapy? Initial experience with recurrent intracranial ependymomas.

OBJECT Although control of intracranial ependymomas is highly correlated with degree of resection, it is unknown if the same is true for MRI-guided laser-induced thermal therapy (MRgLITT). The authors report their experience with MRgLITT for ependymoma and examine the utility of the real-time thermal damage estimate (TDE), a recent software advance, with respect to completeness of ablation and impact on tumor control. To the authors' knowledge, this is the largest single-center experience utilizing MRgLITT for recurrent ependymomas. METHODS Five tumors in 4 patients were treated with the Visualase Thermal Therapy System. Two tumors were treated similarly on recurrence. Ablation was performed using a 980-nm diode laser with a real-time image acquisition system. Single-plane TDEs were calculated and compared with the original lesion area to compute percentage area ablated (PAA). Volumetric analysis was performed, and percentage volume ablated (PVA) was estimated and correlated with the TDE. Tumor control was correlated with the TDE and volumetric data during treatment. RESULTS Nine ablations were performed on 5 tumors, 2 of which had multiple recurrences. The average pretreatment lesion volume was 8.4 ± 6.3 cm(3), and the average largest 2D area was 5.3 ± 2.7 cm(2). The averaged TDE was 3.9 ± 2.1 cm(2), average PAA was 80.1% ± 34.3%, and average PVA was 64.4% ± 23.5%. For subtotal ablations, average recurrence time was 4.4 ± 5.3 months; 1 adult case remains recurrence-free at 40 months. Using TDEs, the correlation between recurrence time and PAA was r = 0.93 (p = 0.01), and for PVA was r = 0.88 (p = 0.02). Furthermore, PVA and PAA were strongly correlated (r = 0.88, p = 0.02). CONCLUSIONS Through using the PAA, the real-time TDE correlated with the volume of ablation in this initial investigation. Furthermore, the TDE and volumetric data corresponded to the level of tumor control, with time to recurrence dependent on ablation completeness. MRgLITT may have a role in the management of recurrent ependymomas, especially with recent software advances.

Volumetric trends associated with MRI-guided laser-induced thermal therapy (LITT) for intracranial tumors.

BACKGROUND: MR-guided Laser Induced Thermal Therapy (LITT) is a procedure for intracranial tumors. Minimal data exists regarding post-procedure lesion volume changes. OBJECTIVES: We aim to analyze changes in lesion volume during the post-LITT period using polygonal tracing with fusion. Additionally, we investigated the role of lesion histopathology on LITT parameters and volume dynamics. METHODS: Sixteen patients with intracranial neoplasms received LITT. Using OsiriX DICOM Viewer, three raters computed lesion volumes at the following: pre-ablation (PreA), immediate post-ablation (IPA), 24 hours post-ablation (24PA), and first follow-up post-ablation (FPA), which ranged from 4 to 11 weeks post-ablation. Statistical analyses for volume changes between time points and inter-rater reliability were performed. Additionally, comparisons were made between metastatic versus non-metastatic and small versus large lesions in terms of operative parameters and volume changes. RESULTS: There was an acute increase in volume at IPA with a decrease in size by 24PA. ANOVA among inter-rater datasets showed no significant difference at any time point (highest F(1,15) = 0.225, P > 0.80, for IPA). GLM repeated measures, for Intra-Rater analysis, demonstrated statistically significant differences across time points (lowest F(1,15) = 13.297, P = 0.003). IPA volumes were larger than those at PreA, 24PA, and FPA (average volume increase [95% CI]: 281% [157-404%], 167% [134-201%], 187% [154-219%], respectively; all P < 0.004). Correlation analysis showed lower inter-rater reliability at IPA versus other time points (all P < 0.03). Larger lesions (>2.5 cm³ ) versus smaller (<2.5 cm³ ) did not demonstrate a difference in percent volume increase. Operative parameters and volume dynamics were not different between metastatic and non-metastatic groups. CONCLUSIONS: The response of intracranial lesions to LITT demonstrates a peak in volume at the IPA time point with decreased IPA inter-rater reliability. We recommend that conclusions about intracranial lesion size post-LITT be made at least 24 hours post-LITT rather than immediately after LITT.

Cost-effectiveness of digital subtraction angiography in the setting of computed tomographic angiography negative subarachnoid hemorrhage.

BACKGROUND: Recent studies have documented the high sensitivity of computed tomography angiography (CTA) in detecting a ruptured aneurysm in the presence of acute subarachnoid hemorrhage (SAH). The practice of digital subtraction angiography (DSA) when CTA does not reveal an aneurysm has thus been called into question. OBJECTIVE: We examined this dilemma from a cost-effectiveness perspective by using current decision analysis techniques. METHODS: A decision tree was created with the use of TreeAge Pro Suite 2012; in 1 arm, a CTA-negative SAH was followed up with DSA; in the other arm, patients were observed without further imaging. Based on literature review, costs and utilities were assigned to each potential outcome. Base-case and sensitivity analyses were performed to determine the cost-effectiveness of each strategy. A Monte Carlo simulation was then conducted by sampling each variable over a plausible distribution to evaluate the robustness of the model. RESULTS: With the use of a negative predictive value of 95.7% for CTA, observation was found to be the most cost-effective strategy ($6737/Quality Adjusted Life Year [QALY] vs $8460/QALY) in the base-case analysis. One-way sensitivity analysis demonstrated that DSA became the more cost-effective option if the negative predictive value of CTA fell below 93.72%. The Monte Carlo simulation produced an incremental cost-effectiveness ratio of $83 083/QALY. At the conventional willingness-to-pay threshold of $50 000/QALY, observation was the more cost-effective strategy in 83.6% of simulations. CONCLUSION: The decision to perform a DSA in CTA-negative SAH depends strongly on the sensitivity of CTA, and therefore must be evaluated at each center treating these types of patients. Given the high sensitivity of CTA reported in the current literature, performing DSA on all patients with CTA negative SAH may not be cost-effective at every institution.

Magnetic resonance thermometry-guided laser-induced thermal therapy for intracranial neoplasms: initial experience.

BACKGROUND: Laser-induced thermal therapy is a promising tool in the neurosurgeon's armamentarium. This methodology has seen a resurgence in application as a result of advances in technology. OBJECTIVE: To report our initial experience with the procedure after treating 20 consecutive patients, the largest series to date. METHODS: Patients were selected for laser therapy if they had failed conventional therapies, were unable to tolerate an open cranial procedure, or the tumor was deemed otherwise inoperable. In this series, 980-nm diode laser catheters were placed stereotactically in the operating room. The patients were then transferred to the magnetic resonance imaging suite for thermal ablation. RESULTS: A total of 31 laser applicators were placed in 20 patients with intracranial neoplasms. The majority of patients (17 of 20) had prior treatment for their tumors. The overall accuracy of laser insertion was 83.9%, improving with increased experience. The average lesion volume treated was 7.0 ± 9.0 cm2. With the use of damage estimates from the software provided, the treatment continued until the entire tumor had been irreversibly ablated. The average length of hospitalization was 2.27 days, with the majority of patients going home on postoperative day 1. Complications occurred in 4 patients, typically in those who were in poor health preoperatively. CONCLUSION: Laser-induced thermal therapy is an intuitive procedure for treating difficult intracranial neoplasms. As with any other procedure, patient selection and lesion selection are important factors in determining outcome.

Strategies for asymptomatic carotid artery stenosis.

The treatment of asymptomatic carotid artery stenosis (ACAS) has continued to evolve for the past 3 decades. With rapidly advancing technology, the results of old trials have become obsolete. While there has been little change in the efficacy of carotid endarterectomy, there have been vast improvements in both medical management and carotid angioplasty with stenting. Finding the best therapy for a given patient can therefore be difficult. In this article, the authors review the current literature regarding treatment options for ACAS and the methods available for stratifying patients who would benefit from surgical versus medical treatment.

Treatment of a supratentorial primitive neuroectodermal tumor using magnetic resonance-guided laser-induced thermal therapy.

Supratentorial primitive neuroectodermal tumors (PNETs) are rare tumors that carry a poorer prognosis than those arising from the infratentorial compartment (such as medulloblastoma). The overall prognosis for these patients depends on several factors including the extent of resection, age at diagnosis, CSF dissemination, and site in the supratentorial space. The authors present the first case of a patient with a newly diagnosed supratentorial PNET in which cytoreduction was achieved with MR-guided laser-induced thermal therapy. A 10-year-old girl presented with left-sided facial weakness and a large right thalamic mass extending into the right midbrain. The diagnosis of supratentorial PNET was made after stereotactic biopsy. Therapeutic options for this lesion were limited because of the risks of postoperative neurological deficits with resection. The patient underwent MR-guided laser-induced thermal ablation of her tumor. Under real-time MR thermometry, thermal energy was delivered to the tumor at a core temperature of 90°C for a total of 960 seconds. The patient underwent follow-up MR imaging at regular intervals to evaluate the tumor response to the thermal ablation procedure. Initial postoperative scans showed an increase in the size of the lesion as well as the amount of the associated edema. Both the size of the lesion and the edema stabilized by 1 week and then decreased below preablation levels at the 3-month postsurgical follow-up. There was a slight increase in the size of the lesion and associated edema at the 6-month follow-up scan, presumably due to concomitant radiation she received as part of her postoperative care. The patient tolerated the procedure well and has had resolution of her symptoms since surgery. Further study is needed to assess the role of laser-induced thermal therapy for the treatment of intracranial tumors. As such, it is a promising tool in the neurosurgical armamentarium. Postoperative imaging has shown no evidence of definitive recurrence at the 6-month follow-up period, but longer-term follow-up is required to assess for late recurrence.