The evolution of surgery for colorectal liver metastases: A persistent challenge to improve survival.

Only a few decades ago, the opinion that colorectal liver metastases were a palliative diagnosis changed. In fact, previously, the prevailing view was strongly resistant against resecting colorectal liver metastases. Constant technical improvement of liver surgery and, much later, effective chemotherapy allowed for a successful wider application of surgery. The clinical use of portal vein embolization was the starting signal of regenerative liver surgery, where insufficient liver volume can be expanded to an extent where safe resection is possible. Today, a number of these techniques including portal vein ligation, associating liver partition and portal vein ligation for staged hepatectomy, and bi-embolization (portal and hepatic vein) can be successfully used to address an insufficient future liver remnant in staged resections. It turned out that the road to success is embedding surgery in a well-orchestrated oncological concept of controlling systemic disease. This concept was the prerequisite that meant liver transplantation could enter the treatment strategy for colorectal liver metastases, ending up with a 5-year overall survival of 80% in highly selected cases. In particular, techniques combining principles of 2-stage hepatectomy and liver transplantation, such as "resection and partial liver segment 2-3 transplantation with delayed total hepatectomy" (RAPID) are on the rise. These techniques enable the use of partial liver grafts with primarily insufficient liver volume. All this progress also prompted a number of innovative local therapies to address recurrences ultimately transferring colorectal liver metastases from instantly deadly into a chronic disease in some cases.

Multiple pipeline embolization devices improves aneurysm occlusion without increasing morbidity: A single center experience of 140 cases.

INTRODUCTION: Rates of aneurysm occlusion with the pipeline embolization device (PED) has varied widely in the literature from 55.7% to 93.3% at 6 months, which may reflect a difference in technique including sizing and number of devices used. METHODS: 140 cases at our institution were retrospectively reviewed, and aneurysms treated with a single PED vs. multiple were compared. RESULTS: Complete aneurysm occlusion was achieved in 86.9% at 6 months, 91.8% at 1 year, and 97.6% at longest follow-up. Retreatment with an additional device was required in 7 (5.1%). Major and minor complication rate within 30 days was 1.4% and 5.0%, and at greater than 30 days was 0.8% and 3.1%. Patients treated with multiple PEDs had significantly higher rates of aneurysm occlusion at 6 months (92.9% vs. 75.6%, p = 0.017) and 12 months (98.4% vs. 81.1%, p = 0.014), with no difference in complications. The two groups were similar aside from a higher number of ophthalmic and paraophthalmic aneurysms treated with multiple PEDs (23.4% vs. 6.5%, p = 0.004; and 35.1% vs. 17.4%, p = 0.020), and more posterior communicating artery and recurrent aneurysms treated with a single PED (28.3% vs. 3.2%, p = 0.001; 23.9% vs. 8.5%, p = 0.031). The use of multiple PEDs was found to be an independent predictor of aneurysm occlusion in a multivariate analysis (p = 0.015). CONCLUSIONS: The use of multiple PEDs for intracranial aneurysms leads to significantly higher occlusion rates without added morbidity. This benefit is particularly appropriate for ophthalmic segment aneurysms, while more distal segments with eloquent perforating branches should be managed with caution.

Pipeline Embolization Device for Intracranial Aneurysms in a Large Chinese Cohort: Complication Risk Factor Analysis.

During intracranial aneurysm embolization with the Pipeline embolization device (PED), ischemic and hemorrhagic complications have been observed in cases among Western populations. The postmarket multicenter registry study on the embolization of intracranial aneurysms with the PED in China, i.e., the PLUS study, was performed to assess real-world predictors of complications and functional outcomes in patients treated with the PED in a Chinese population. All patients with intracranial aneurysms who underwent embolization using the PED between November 2014 and October 2019 across 14 centers in China were included. The study endpoints included preoperative and early postoperative (< 30 days) functional outcomes (modified Rankin scale [mRS] scores) and complications related to PED treatment at early postoperative and follow-up time points (3-36 months). Multivariate analysis was performed to identify risk factors for complications. A total of 1171 consecutive patients (mean age, 53.9 ± 11.4; female, 69.6% [813/1171]) with 1322 aneurysms were included in the study. Hypertension, basilar artery aneurysms, and successful deployment after adjustment or unsuccessful device deployment were found to be independent predictors of ischemic stroke, while the use of the Flex PED and incomplete occlusion immediately after treatment were protective factors. An aneurysm size > 10 mm, distal anterior circulation aneurysms, and adjunctive coiling were found to be independent predictors of delayed aneurysm rupture, distal intraparenchymal hemorrhage, and neurological compression symptoms, respectively. The rate of PED-related complications in the PLUS study was similar to that in Western populations. The PLUS study identified successful deployment after adjustment or unsuccessful device deployment and the degree of immediate postoperative occlusion as novel independent predictors of PED-related ischemic stroke in a Chinese population. ClinicalTrial.gov Identifier: NCT03831672.

Cognitive outcomes after unruptured intracranial aneurysm treatment with endovascular coiling.

BACKGROUND: We aimed to determine the effects of endovascular coiling of unruptured intracranial aneurysms (UIAs) on cognition to inform treatment decisions. We present the first study using the Montreal Cognitive Assessment (MoCA) to determine neurocognitive changes after endovascular coiling. METHODS: We prospectively collected data on all patients with UIAs undergoing endovascular coiling, primary or assisted. Patients completed the MoCA prior to intervention and 1 month and 6 months' post-procedure. A repeated measures linear mixed effects model was used to compare pre-procedure and post-procedure cognition. RESULTS: Thirty-three patients with 33 aneurysms who underwent coiling from April 2017 to May 2020 were included (mean age 55.5, 81.8% female). All procedures used general anesthesia. There was no difference between baseline and post-procedure MoCA scores at any time interval (P>0.05). Mean MoCA scores at baseline, 1 month post-procedure, and 6 months' post-procedure were 25.4, 26.8, and 26.3 respectively. There was also no difference between pre- and post-procedure scores on any individual MoCA domain (visuospatial, naming, memory, attention, language, abstraction, delayed recall, and orientation) at any time interval (P>0.05). Seventeen patients had follow-up MRI or CT imaging, of which 11.8% showed radiographic changes or ischemia. 77.8% of patients with 6-month angiographic follow-up achieved class I, and 22.2% achieved class II Raymond-Roy Occlusion. Thirty-two out of 33 patients had follow-up mRS ≤2. CONCLUSION: Our study suggests that endovascular coiling does not diminish neurocognitive function. Patients with UIAs in our cohort also had baseline MoCA scores below the cut-off for mild cognitive impairment despite pre-procedure mRS and NIHSS of 0.

Outcome of retreatment for recurrent saccular cerebral aneurysms: a propensity score-matched analysis.

Although endovascular or surgical treatment has been performed for preventing the rupture of saccular cerebral aneurysms (sCA), in some patients, the aneurysms may recur and require retreatment. We aimed to investigate the clinical and radiological outcomes of treating recurrent sCA. We retrospectively evaluated the data of 52 patients with 60 recurrent sCAs who were retreated and 1534 patients with 1817 sCAs who received initial treatment. The primary outcome was a recurrence of the aneurysm. Secondary outcomes were an additional treatment, rupture after treatment, and a neurological worsening, which was defined as an increase of 1 or more scores using the modified Rankin Scale at 12-month. Safety outcomes included postoperative ischemic and hemorrhagic complications. We compiled the 120 (60 each) propensity score-matched cohort based on a propensity score for the treatment of recurrent sCA. In the propensity score-matched cohort, recurrence after treatment was observed in 25% and 6.7% of cases in the retreatment and initial treatment groups, respectively. The odds ratio of recurrence after treatment was 4.7 (95% CI, 1.4-15; P = 0.011). The secondary and safety outcomes were not significantly different between the two groups. This study showed that the treatment of recurrent sCA was a risk factor for recurrence after treatment but not for additional treatment, rupture after treatment, or neurological worsening. Although decision-making regarding the treatment varies depending on the institutional protocols and personal experience of the physicians, endovascular or surgical retreatment could be performed without hesitation.

Microsurgery of residual or recurrent complex intracranial aneurysms after coil embolization - a quest for the ultimate therapy.

The long-term stability of coil embolization (CE) of complex intracranial aneurysms (CIAs) is fraught with high rates of recanalization. Surgery of precoiled CIAs, however, deviates from a common straightforward procedure, demanding sophisticated strategies. To shed light on the scope and limitations of microsurgical re-treatment, we present our experiences with precoiled CIAs. We retrospectively analysed a consecutive series of 12 patients with precoiled CIAs treated microsurgically over a 5-year period, and provide a critical juxtaposition with the literature. Five aneurysms were located in the posterior circulation, 8 were large-giant sized, 5 were calcified/thrombosed. One presented as a dissecting-fusiform aneurysm, 9 ranked among wide neck aneurysms. Eight lesions were excluded by neck clipping (5 necessitating coil extraction); 1 requiring adjunct CE. The dissecting-fusiform aneurysm was resected with reconstruction of the parent artery using a radial artery graft. Three lesions were treated with flow alteration (parent artery occlusion under bypass protection). Mean interval coiling-surgery was 4.6 years (range 0.5-12 years). Overall, 10 aneurysms were successfully excluded; 2 lesions treated with flow alteration displayed partial thrombosis, progressing over time. Outcome was good in 8 and poor in 4 patients (2 experiencing delayed neurological morbidity), and mean follow-up was 24.3 months. No mortality was encountered. Microsurgery as a last resort for precoiled CIAs can provide-in a majority of cases-a definitive therapy with good outcome. Since repeat coiling increases the complexity of later surgical treatment, we recommend for this subgroup of aneurysms a critical evaluation of CE as an option for re-treatment.

Nuisance bleeding complications in patients with cerebral aneurysm treated with Pipeline embolization device.

BACKGROUND: Patients with cerebral aneurysms treated with the Pipeline embolization device (PED) are maintained on dual antiplatelet therapy (DAPT) to prevent thromboembolic complications. Rates of minor, "nuisance" bleeding in these patients remain unknown. We sought to evaluate the frequency and factors associated with this bleeding and its effect on DAPT compliance. METHODS: We performed a multicenter retrospective cohort study on consecutive cases of intracranial aneurysms treated with PED. Patient characteristics, aneurysm characteristics, and bleeding complications were analyzed. Severity of bleeding was defined according to a previously published classification defining nuisance bleeding as easy bruising, bleeding from small cuts, petechia, and ecchymosis. RESULTS: 245 PED aneurysm procedures on 243 patients were retrospectively collected from three academic centers over a 4.25-year period. Sixty-seven patients (27%) had nuisance bleeds. Patients with a higher risk of nuisance bleeding were older (59.1±3.4 vs . 54.7±2.2, P=0.032). Patients with nuisance bleeds were more likely to have their DAPT regimen changed or dose lowered (29% vs 8.3%, P<0.001), were on DAPT for less time (10.0 months±2.60 vs. 14.6 months±1.95, P=0.005) and were more likely to have aneurysm occlusion at 6 months (P<0.001). Stepwise logistic regression found age predictive of a nuisance bleed (OR=1.033) CONCLUSIONS: Nuisance bleeding was a common complaint of PED-treated aneurysm patients maintained on DAPT. Increasing age and aneurysmal occlusion at 6 months were the only factors predictive of nuisance bleeds. Clinicians were more likely to adjust antiplatelet regimens or stop DAPT early given a nuisance bleed.

Follow-up outcomes of intracranial aneurysms treated using braided or laser-cut stents with closed-cell design: a propensity score-matched case-controlled comparison.

BACKGROUND: The impact of various stents on patients with intracranial aneurysms who undergo stent-assisted coiling has been debated. We conducted this study to compare follow-up outcomes of coiling procedures involving braided or laser-cut stents with closed-cell design. A propensity score-matched case-controlled analysis was applied. METHODS: A total of 413 intracranial aneurysms consecutively coiled using laser-cut (n=245) or braided stents (n=168) in procedures performed between September 2012 and June 2017 were eligible for study. Time-of-flight magnetic resonance angiography, catheter angiography, or both were used to gauge occlusive status after coiling. Recanalization was determined by Raymond classification (complete occlusion vs recanalization). A propensity score-matched analysis was conducted, based on probability of stent type in use. RESULTS: Ultimately, 93 coiled aneurysms (22.5%) showed some recanalization (minor, 51; major, 42) during the follow-up period (mean 21.7±14.5 months). Patient gender (P=0.042), hyperlipidemia (P=0.015), size of aneurysm (P=0.004), neck size (P<0.001), type of aneurysm (P<0.001), and packing density (P=0.024) differed significantly by group. Midterm and cumulative recanalization incidence rates in the braided-stent group were initially lower than those of the laser-cut stent group (P=0.009 and P=0.037, respectively) but they did not differ significantly after 1:1 propensity score matching (midterm OR=0.88, P=0.724; cumulative HR=0.91, P=0.758). CONCLUSION: In stent-assisted coiling of intracranial aneurysms, laser-cut and braided stent groups produced similar outcomes in follow-up. Consequently, product selection may hinge on suitability for deployment rather than anticipated results.

What's New in Percutaneous Ablative Strategies for Hepatocellular Carcinoma and Colorectal Hepatic Metastases? 2020 Update.

PURPOSE OF REVIEW: Ablation techniques are now well-established treatment options available for the management of primary and secondary hepatic malignancies. Currently available ablative techniques include radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation, and irreversible electroporation (IRE). Along with advances in navigational devices and targeting technologies, ablation combined with other therapies may be the next therapeutic option in thermal ablation. The purpose of this review is to evaluate the current status of ablative technologies in interventional and medical oncology for management of liver malignancies. RECENT FINDINGS: With the use of combination techniques (i.e., ablation and transarterial embolization procedures), thermal ablation is now moving toward treating tumors larger than 3 cm in size or tumors with macrovascular invasion. Ongoing trials are examining the optimum timing of combination therapies. Thermal ablation combined with hepatic resection may increase the number of patients with metastatic colorectal carcinoma to the liver who qualify for curative surgery. Combination therapies of thermal ablation and transarterial embolization allow for promising treatment responses for larger HCC. Surgery combined with thermal ablation can potentially increase the number of patients with metastatic colon cancer to the liver who qualify for curative surgery.

Periprocedural to 1-year safety and efficacy outcomes with the Pipeline Embolization Device with Shield technology for intracranial aneurysms: a prospective, post-market, multi-center study.

BACKGROUND: The first and second generations of the Pipeline Embolization Device (PED) have been widely adopted for the treatment of intracranial aneurysms (IAs) due to their high associated occlusion rates and low morbidity and mortality. The objective of this study was to evaluate the safety and effectiveness of the third- generation Pipeline Shield device (PED-Shield) for the treatment of IAs. METHODS: The SHIELD study was a prospective, single-arm, multicenter, post-market, observational study evaluating the PED-Shield device for the treatment of IAs. The primary efficacy endpoint was complete aneurysm occlusion without significant parent artery stenosis or retreatment at 1-year post-procedure and the primary safety endpoint was major stroke in the territory supplied by the treated artery or neurological death. RESULTS: Of 205 subjects who consented across 21 sites, 204 subjects with 204 target aneurysms were ultimately treated (mean age 54.8±12.81 years, 81.4% [166/204] female). Technical success (ie, deployment of the PED-Shield) was achieved in 98.0% (200/204) of subjects with a mean number of 1.1±0.34 devices per subject and a single device used in 86.8% (177/204) of subjects. The primary effectiveness endpoint was met in 71.7% (143/200) of subjects while the primary safety endpoint occurred in six (2.9%) subjects, two (1.0%) of which led to neurological death. CONCLUSIONS: The findings of the SHIELD study support the safety and effectiveness of the PED-Shield for IA treatment, evidenced by high occlusion rates and low rates of neurological complications in the study population. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT02719522.

Trends in Percutaneous Embolization Procedures by Radiologists and Other Specialists.

PURPOSE: To evaluate utilization trends in percutaneous embolization among radiologists and nonradiologist providers. MATERIALS AND METHODS: The nationwide Medicare Part B fee-for-service databases for 2005-2016 were used to evaluate percutaneous embolization codes. Six codes describing embolization procedures were reviewed. Physician providers were grouped as radiologists, vascular surgeons, cardiologists, nephrologists, other surgeons, and all others. RESULTS: The total volume of Medicare percutaneous embolization procedures increased from 20,262 in 2005 to 45,478 in 2016 (+125%). Radiologists performed 13,872 procedures in 2005 (68% of total volume) and 33,254 in 2016 (73% of total volume), a 140% increase in volume. While other specialists also increased the number of cases performed from 2005 to 2016, radiologists strongly predominated, performing 87% of arterial and 30% of venous procedures in 2016, more than any other single specialty. In 2014 and 2015, a sharp increase in venous embolization cases performed by nonradiologists preceded a sharp decrease in 2016, likely the result of complicated billing codes for venous procedures. Radiologists maintained a steady upward trend in the number of cases they performed during those years. CONCLUSIONS: The volume of percutaneous embolization procedures performed in the Medicare population increased from 2005 to 2016, reflecting a trend toward minimally invasive intervention. In 2016, radiologists performed nearly 10 times more arterial embolization procedures than the second highest specialty and more venous embolization procedures than any other single specialty.

Safety and efficacy of ticagrelor as single antiplatelet therapy in prevention of thromboembolic complications associated with the Pipeline Embolization Device (PED): multicenter experience.

BACKGROUND: Flow diversion (FD) is a common treatment modality for complex intracranial aneurysms. A major concern regarding the use of FD is thromboembolic events (TEE). There is debate surrounding the optimal antiplatelet regimen to prevent TEE. We aim to evaluate the safety and efficacy of ticagrelor as a single antiplatelet therapy (SAPT) for the prevention of TEE following FD for complex aneurysm treatment. METHODS: A retrospective review of a prospectively maintained neuroendovascular database at three endovascular centers was performed. Patients were included if they had an intracranial aneurysm that was treated with FD between January 2018 and September 2019 and were treated with ticagrelor as SAPT. Primary outcomes included early (within 72 hours post-procedure) and late (within 6 months) ischemic events. RESULTS: A total of 24 patients (mean age 47.7 years) with 36 aneurysms were eligible for analysis, including 15 (62.5%) females. 14 (58.3%) patients presented with subarachnoid hemorrhage. 35 aneurysms arose from the anterior circulation and 1 from the posterior circulation. 23 aneurysms had a saccular morphology, whereas 7 were fusiform and 6 were blister. For the treatment of all 36 aneurysms, 30 procedures were performed with 32 FD devices. Procedural in-stent thrombosis occurred in 2 cases and was treated with intra-arterial tirofiban without complications. Aneurysm re-bleeding was reported in 1 (4.2%) patient. There were no reported early or late TEE. Three patients discontinued ticagrelor due to systemic side effects. CONCLUSION: Ticagrelor is a safe and effective SAPT for the prevention of TEE after FD. Large multicenter prospective studies are warranted to validate our findings.

Middle meningeal artery embolization reduces the post-operative recurrence rate of at-risk chronic subdural hematoma.

BACKGROUND: Embolization of the middle meningeal artery (MMA) has emerged as a potential treatment of chronic subdural hematomas (CSDHs). OBJECTIVE: To evaluate the impact on recurrence rate of postsurgical embolization of CSDH in patients with a higher than average risk of recurrence. METHODS: A monocentric retrospective study was performed on retrospectively collected data. From March 2018 to December 2019, embolization of the MMA was proposed as an adjunct postoperative treatment after burr-hole surgery in patients operated for a recurrent CSDH or a CSDH with an independent recurrence risk factor, including antiplatelet therapy, full anticoagulation therapy, coagulation disorder, hepatopathy, or chronic alcoholism. Patients who had undergone postoperative embolization were compared with a historic group of patients operated between March 2016 and March 2018, selected based on the same inclusion criteria. RESULTS: During the study period, 89 patients (with 74 unilateral and 15 bilateral CSDHs) were included and underwent an embolization procedure, leading to 91 out of a total of 104 MMA being embolized (88%). These were compared with 174 patients (138 unilateral and 36 bilateral CSDH) in the historic control group. One major procedure-related adverse event was registered. Four of the 89 patients (4%) required surgery for a CSDH recurrence in the embolization group, significantly less than the 24 of 174 patients (14%) in the control group (OR=0.28, 95% CI 0.07 to 0.86, p=0.02). CONCLUSIONS: Postsurgical embolization of the MMA may reduce the recurrence rate of CSDHs with a risk factor of recurrence.

Transcatheter arterial embolization for advanced gastric cancer bleeding: A single-center experience with 58 patients.

To investigate computed tomography and angiography findings and clinical outcomes after transcatheter arterial embolization for acute upper gastrointestinal bleeding from advanced gastric cancers.From January 2005 to December 2014, 58 patients with pathologically proven gastric cancer were treated at our institution with transcatheter arterial embolization due to acute upper gastrointestinal bleeding recalcitrant to endoscopic treatment. The electronic medical records for each patient were reviewed for clinical presentation, endoscopy history, computed tomography and angiographic findings, blood transfusion requirements, and follow-up results.Angiography findings were positive in 13 patients (22.4%): contrast extravasation was found in 9 patients and pseudoaneurysm in 4 patients. All patients with positive angiograms underwent selective embolization treatment. Those with negative angiography findings underwent empirical embolization. Gelfoam, n-butyl cyanoacrylate, coils, or a combination of these were used as embolic agents. The overall clinical success rate was 72.4% (42/58), and the success rate for patients with positive angiography was 53.8% (7/13). The median survival was 97.5 days (range, 7-1415 days), and the 1-month survival rate was 89.6% (52/58). The 1-month survival rate of the clinical success group was 95.2% (40/42), which was significantly higher than that of the clinical failure group (P = .04). The clinical success group also required significantly fewer transfusions (2.43 units, range 0-24 units) (P = .02).Transcatheter arterial embolization is a highly effective treatment for advanced gastric cancer with active bleeding. It should be considered as an additional treatment, especially when endoscopic or surgical treatment fails or when these approaches are difficult.

Microsurgical and Endovascular Treatment Outcomes in Pericallosal Artery Aneurysms: A Single Center Retrospective Analysis.

AIM: To summarize the clinical outcomes, follow-up results and to discuss the optimal therapeutic strategy for pericallosal artery aneurysms (PAAs). MATERIAL AND METHODS: From January 2013 to May 2017, the charts of 49 patients with PAAs, representing 2.43% of 2,018 consecutive patients with intracranial aneurysms (IAs) were reviewed. The clinical and radiological data of these patients were retrospectively analyzed. RESULTS: There were no technical failures in the clipping group, but one patient in the coiling group presented rebleeding during the operation, resulting in a poor prognosis. Although the difference was not significant, the coiling group had a better complete recovery rate than the clipping group [overall: coiling, n=20 (87.0%) vs clipping, n=11 (68.8%), p=0.33; unruptured PAAs: coiling, n=12 (92.3%) vs clipping, n=5 (83.3%); ruptured PAAs: coiling, n=8 (80%) vs clipping, n=6 (60%), p=0.63]. One patient in the coiling group exhibited recurrence. No patients experienced rebleeding during the follow-up period in either group. CONCLUSION: In our study, both endovascular coiling and microsurgery were technically feasible and achieved favorable clinical outcomes in patients with PAAs. Longer radiological follow-up is necessary. Patients should be evaluated by a multidisciplinary team prior to determining the optimal treatment modality.

Abscopal effect and interventional oncology: state of art and future perspectives.

OBJECTIVE: The concept of abscopal effect is currently gaining importance in modern oncology, as the link between localized irradiation and triggering of immuno-mediated systemic antitumor effects is getting clearer. An increasing number of reports documented abscopal effect mainly after external beam irradiation. Interventional radiotherapy (IR) may be used with sealed radioactive sources as brachytherapy (BT) or with unsealed radioactive sources as transarterial radioembolization (TARE). The aim of this paper is to review the existing clinical IR data and discuss the mechanisms of the abscopal effect. MATERIALS AND METHODS: A systematic research of the main bibliographic databases (PubMed, WOS, Scopus, and Google Scholar) from the earliest possible date through August 2019 was performed. The search strategy was based on the terms "abscopal effect", "interventional radiotherapy", "brachytherapy" and "TARE". RESULTS: Thirteen titles were identified. Three papers met inclusion criteria and were included in the review. All of them were case reports. CONCLUSIONS: Even though there are still scarce data in literature regarding the association of locoregional interventional treatments with the abscopal effect, this review demonstrates that the immunomodulatory theories, which have been widely used so far for external beam radiotherapy (EBRT), may be actually considered valid also in the contest of IR.

How safe and effective are flow diverters for the treatment of unruptured small/medium intracranial aneurysms of the internal carotid artery? Meta-analysis for evidence-based performance goals.

BACKGROUND: The objective of this meta-analysis was to establish safety and effectiveness benchmarks for endovascular therapy of unruptured small-to-medium internal carotid artery (ICA) aneurysms using flow diverters. METHODS: A systematic literature review and subsequent meta-analysis were performed using best research methods. Studies of any design with at least 10 patients treated with flow diverters for predominantly (≥90%) unruptured small/medium ICA aneurysms and ≥6 month follow-up were included. The primary effectiveness endpoint was complete aneurysm occlusion rate at 12 months. The primary safety endpoint was a composite measure of cumulative events that could indicate a stroke or neurologic death: any death, stroke, intracranial hemorrhage, or worsening on the modified Rankin Scale. RESULTS: 41 studies (2614 patients) met eligibility criteria for the meta-analysis. The core lab adjusted complete occlusion rate was 74.9% (95% CI 69.6% to 79.8%) at 12 months for studies using any flow diverter. With an aim of generating performance goals for a US Investigational Device Exemption (IDE) study, a pre-specified analysis was conducted using only studies with flow diverters commercially available in the USA. In this cohort, 12 month complete occlusion was 74.6% (95% CI 66.8% to 81.7%). The primary safety event rate for flow diverters commercially available in the USA was 7.8% (95% CI 4.8% to 11.4%). CONCLUSIONS: The treatment of small and medium-sized aneurysms with flow diverters is effective in achieving curative reconstruction in most cases and is associated with low rates of morbidity and mortality. This meta-analysis informs robust performance goals for evaluating new flow diverters in small/medium unruptured carotid aneurysms.

Treatment and diagnosis of cerebral aneurysms in the post-International Subarachnoid Aneurysm Trial (ISAT) era: trends and outcomes.

BACKGROUND: Following publication of the International Subarachnoid Aneurysm Trial (ISAT), treatment paradigms for cerebral aneurysms (CAs) shifted from open surgical clipping to endovascular embolization as primary therapy in a majority of cases. However, comprehensive analyses evaluating more recent CA diagnosis patterns, patient populations and outcomes as a function of treatment modality remain rare. METHODS: The National Inpatient Sample from 2004 to 2014 was reviewed. Aneurysmal subarachnoid hemorrhages (aSAHs) and unruptured intracranial aneurysms (UIAs) with a treatment of surgical clipping or endovascular therapy (EVT) were identified. Time trend series plots were created. Linear and logistic regressions were utilized to quantify treatment changes. RESULTS: 114 137 aSAHs and 122 916 UIAs were reviewed. aSAH (+732/year, p=0.014) and UIA (+2550/year, p<0.0001) discharges increased annually. The annual caseload of surgical clippings for aSAH decreased (-264/year, p=0.0002) while EVT increased (+366/year, p=0.0003). For UIAs, the annual caseload for surgical clipping remained stable but increased for EVT (+615/year, p<0.0001). The rate of incidentally diagnosed UIAs increased annually (+1987/year; p<0.0001). Inpatient mortality decreased for clipping (p<0.0001) and EVT in aSAH (p<0.0001) (2004 vs 2014-clipping 13% vs 11.7%, EVT 15.8% vs 12.7%). Mortality rates for clipped UIAs decreased over time (p<0.0001) and remained stable for EVT (2004 vs 2014-clipping 1.57% vs 0.40%, EVT 0.59% vs 0.52%). CONCLUSION: Ruptured and unruptured CAs are increasingly being treated with EVT over clipping. Incidental unruptured aneurysm diagnoses are increasing dramatically. Mortality rates of ruptured aneurysms are improving regardless of treatment modality, whereas mortality in unruptured aneurysms is only improving for surgical clipping.

Surgical Versus Endovascular Management of Ruptured and Unruptured Intracranial Aneurysms: Emergent Issues and Future Directions.

Ideal management of unruptured intracranial aneurysms (UIAs) and ruptured intracranial aneurysms (RIAs) is a controversial issue. Over the last few decades, a significant paradigm shift has occurred away from open microsurgical clipping toward endovascular coil embolization. Multiple studies have been performed with mixed results. Some studies suggest that endovascular treatment produces better clinical and functional outcomes, but is associated with increased need for retreatment. Other studies report increased durability in aneurysms treated with microsurgical clipping, but that clipping may be associated with worse functional outcomes in some cases. Further complicating the dialogue are variable costs associated with different treatment modalities, including country-dependent cost differences. Here we provide a review of some of the major studies comparing open surgery versus endovascular treatment for both RIAs and UIAs to distill their key findings and corresponding implications for clinical practice. We relate these research results to our institution's experience with RIAs and UIAs and describe our approach to treatment of these conditions. Finally, we discuss implications of the paradigm shift for both open and endovascular surgery, including educational initiatives directed toward preserving important microsurgical tenets in the setting of diminishing surgical volume.