Srinivasan, Visish M.

Background Arteriovenous malformations (AVMs) are uncommon cerebral lesions that can cause significant neurological complications. Surgical resection is the gold standard for treatment, but endovascular embolization and stereotactic radiosurgery (SRS) are viable alternatives. Objective To compare the outcomes of endovascular embolization versus SRS in the treatment of AVMs with Spetzler-Martin grades I–III. Methods This study combined retrospective data from 10 academic institutions in North America and Europe. Patients aged 1 to 90 years who underwent endovascular embolization or SRS for AVMs with Spetzler-Martin grades I–III between January 2010 and December 2023 were included. Results The study included 244 patients, including 84 who had endovascular embolization and 160 who had SRS. Before propensity score matching (PSM), complete obliteration at the last follow-up was achieved in 74.5% of the SRS group compared with 57.8% of the embolization group (OR=0.47; 95% CI 0.26 to 0.48; P=0.01). After propensity score matching, SRS still achieved significantly higher occlusion rates at last follow-up (78.9% vs 55.3%; OR=0.32; 95% CI 0.12 to 0.90; P=0.03). Hemorrhagic complications were higher in the embolization group than in the SRS group, although this difference did not reach statistical significance after PSM (13.2% vs 2.6%; OR=5.6; 95% CI 0.62 to 50.47; P=0.12). Similarly, re-treatment rate was higher in the embolization group (10.5% vs 5.3%; OR=2.11; 95% CI 0.36 to 12.31; P=0.40) compared with the SRS group. Conclusion Our findings indicate that SRS has a significantly higher obliteration rate at last follow-up compared with endovascular embolization. Also, SRS has a higher tendency for fewer hemorrhagic complications and lower re-treatment rate. Further prospective studies are needed.

BACKGROUND AND OBJECTIVES: Predicting functional outcomes after surgical management of ruptured aneurysms is essential. This study sought to validate the modified Southwestern Aneurysm Severity Index (mSASI), which predicts functional outcomes 1 year after treatment. METHODS: The surgical arm of a randomized controlled trial, the Barrow Ruptured Aneurysm Trial, was used to validate the mSASI model. mSASI scores incorporating the Hunt and Hess scale, Non-Neurological American Society of Anesthesiologists Physical Classification Status, imaging findings, and other modifiers were assigned and evaluated against the Glasgow Outcome Scale (GOS) score at 1 year. The model's performance was assessed for discrimination and calibration. Similar evaluations were constructed using the modified Rankin Scale (mRS) as the 1-year functional outcome measurement. Long-term outcomes (3, 6, 10 years) were also evaluated. RESULTS: Of 280 clinical trial patients treated surgically, 242 met the inclusion criteria. The mean age was 54.1 ± 12.9 years; 31% were men. Favorable GOS score (4-5) and mRS score (0-2) at 1 year were observed in 73.6% and 66.1% of patients, respectively. The mSASI model predicted unfavorable GOS score at 1 year with fair to good discrimination (area under the curve = 0.75, 95% CI = 0.68-0.82) and accurate calibration (R 2 = 0.98). Similar results were obtained when mRS was used as the outcome measure (area under the curve = 0.75, 95% CI = 0.68-0.82; R 2 = 0.95). CONCLUSION: The mSASI model was externally validated in our cohort to predict functional outcomes using the GOS or mRS scores 1 year after surgery. This index may be used for prognosticating outcomes of patients undergoing surgery for ruptured aneurysms at short-term and long-term intervals.

Introduction While neurovascular surgeries have largely been performed by neurosurgeons, the advent of endovascular procedures has produced increasing involvement of other specialists in this arena (i.e. neurologists and radiologists).This study aims to analyzethe involvement of different specialties within theneuroendovascular workforce by characterizingthem by their primary specialty. Methods The Medicare Provider Utilization Database was queried from 2013 to 2019 for all primary Current Procedural Terminology (CPT) codes identified by the American Medical Association as pertaining to endovascular procedures of the nervous system (61623, 61624, 61630, 61635, 61626, 61645, and 61650). We counted the number of unique providers in respective fields (neurology, neurosurgery, and radiology) who performed these procedures. Statistical analyses, including data aggregation, exploratory analysis, and propensity adjustment, were performed using R, version 4.0.1 (The R Foundation, Vienna, Austria). The two‐sided Mann‐Kendall trend test, a non‐parametric statistical test that assesses for monotonic trends in either an upward or downward trend, was utilized to assess for trends over time. Within each year analyzed, a Chi‐squared test for trend in proportions was used. A significance level of 0.05 was used. Results In 2013, neurosurgeons comprised 45% of the workforce performing these procedures, neurologists were 9%, and radiologists were 47%. By 2019, neurosurgeons decreased to 34.5% of the workforce, while neurologists increased to 21.5%, and radiologists decreased slightly to 44%. Neurologists were the only field in which the proportional shift in providers was noted to have a significant change in trajectory (p:0.04), an upward trajectory. Overall proportional differences between respective specialists were statistically significant each year (p< 0.01). Conclusions Neurologists are increasingly performing endovascular procedures. Increased communication and coordination between specialties can improve disparities in care to ensure adequate access to neurovascular care across the US.

Introduction Endovascular procedures have become increasingly popular in recent years due to preference of minimally invasive approaches and technological advancement.This study aims to characterize the trends in procedural rates of common neuro‐endovascular procedures performed by neurologists, neurosurgeons, and radiologists. Methods The Medicare Provider Utilization Database was queried from 2013 to 2019 for all primary Current Procedural Terminology codes identified by the American Medical Association as pertaining to endovascular procedures of the nervous system (61623, 61624, 61630, 61635, 61626, 61645, and 61650). Statistical analyses, including data aggregation, exploratory analysis, and propensity adjustment, were performed using R, version 4.0.1 (The R Foundation, Vienna, Austria). The two‐sided Mann‐Kendall trend test, a non‐parametric statistical test that assesses for monotonic trends in either an upward or downward trend, was utilized to assess for trends over time. A significance level of 0.05 was used. Results Between 2013 to 2019 a total of 40,730 endovascular procedures were performed by neurosurgeons, neurologists and radiologists treating Medicare patients. When all codes were combined, there was a significant increase in the number of procedures done by all specialists: Radiology (2013:1080; 2019:4938; p:0.02), Neurosurgery (2013:1230; 2019:4508; p< 0.01), and Neurology (2013:205; 2019:2397; p:0.04). Significant increases in mechanical thrombectomy (CPT61645) were observed in all fields: Radiology (2016:1287, 2019:3542; p< 0.01), Neurosurgery (2016:610; 2019:2326; p< 0.01), Neurology (2016:569; 2019:1951; p< 0.01). Increases in transcatheter permanent occlusion (CPT61624) were observed in neurosurgery (2013:1230; 2019:2049; p:0.04). Increases in temporary balloon artery occlusion (CPT61623) were noted in neurology (2013:21; 2019:27; p:0.04). Conclusions Endovascular procedures have seen a dramatic rise in utilization over a short amount of time, particularly mechanical thrombectomy. Future investigation should include more inclusive datasets beyond the Medicare population.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

OBJECTIVE Traditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device. METHODS This study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications. RESULTS A total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A 1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a device-related intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2. CONCLUSIONS PulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

The Pipeline Embolization Device (PED) was approved for the treatment of intracranial aneurysms from the petrous to the superior hypophyseal segment of the internal carotid artery. However, since its approval, its use for treatment of intracranial aneurysms in other locations and non-sidewall aneurysms has grown tremendously. The authors report on a cohort of 15 patients with 16 cerebral aneurysms that incorporated an end vessel with no significant distal collaterals, which were treated with the PED. The cohort includes 7 posterior communicating artery aneurysms, 5 ophthalmic artery aneurysms, 1 superior cerebellar artery aneurysm, 1 anterior inferior cerebellar artery aneurysm, and 2 middle cerebral artery aneurysms. None of the aneurysms achieved significant occlusion at the last follow-up evaluation (mean 24 months). Based on these observations, the authors do not recommend the use of flow diverters for the treatment of this subset of cerebral aneurysms.