Rinaldo, Lorenzo

Abstract Dr Thoralf Sundt III joined the department of neurosurgery at Mayo Clinic in 1969 and served as chairman from 1980 until his death in 1992. Dr Sundt was a pioneer in the field of cerebrovascular neurosurgery and among his many contributions to neurosurgical technology was the introduction of the Sundt clip graft (Codman, Raynham, Massachusetts), which was developed in partnership with Dr George Kees. This device is a vessel-encircling Teflon or Dacron graft loaded on a circular metallic spring initially designed to repair injuries to vessel walls during intracranial aneurysm surgery, 1 which was not an uncommon complication resulting from the use of contemporary aneurysm clips. 2 When used for this purpose, the clip graft has demonstrated both safety and efficacy in a modern series of surgical treatment of intracranial aneurysm. 3 An additional application of the clip graft is the direct clipping of aneurysms, particularly side-wall aneurysms, though Dr Sundt recognized that the potential to occlude perforating arteries adjacent to the aneurysm neck would limit the general use of the clip graft for aneurysm clipping. 2 In the following video, we present archival footage of Dr Sundt utilizing the Sundt clip graft during intracranial aneurysm surgery. The 3 cases are of the treatment of posterior communicating, middle cerebral, and anterior communicating artery aneurysms and depict the potential applications of the clip graft during aneurysm surgery. We also present footage of animal experiments Dr Sundt performed to validate the use of the clip graft. This footage likely represents some of the first microscopic neurosurgical recordings ever made. The patients consented to the procedure and to presentation of video recordings at the time of initial surgery. Image of Sundt at 0:11, Reproduced with permission from the American Association of Neurological Surgeons, 5550 Meadowbrook Dr, Rolling Meadows, IL 60008. Figures at 2:26 and 2:28, from Park PJ, Meyer FB, The Sundt clip graft, Neurosurgery , 2010;66(6 suppl operative):300-305, by permission of the Congress of Neurological Surgeons. Figure at 2:35, ©2009 Mayo, Clingman. Used with permission.

Background Over the past several years there has been increased interest in the use of the Sofia aspiration system (MicroVention, Tustin, California) as a primary aspiration catheter. Objective To perform a multicenter retrospective study examining the efficacy of the Sofia aspiration catheter as a standalone aspiration treatment for large vessel occlusion. Methods Consecutive cases in which the Sofia catheter was used for aspiration thrombectomy for large vessel occlusion were included. Exclusion criteria were the following: (1) Sofia not used for first pass, and (2) a stent retriever used as an adjunct on the first pass. The primary outcome of the study was first pass recanalization (Thrombolysis in Cerebral Infarction (TICI) 2c/3). Secondary outcomes included first pass TICI 2b/3, crossover to other thrombectomy devices, number of passes, time from puncture to recanalization, and complications. Results 323 patients were included. First pass TICI 2c/3 was achieved in 49.8% of cases (161/323). First pass TICI 2b/3 was achieved in 69.7% (225/323) of cases. 74.8% had TICI 2b/3 with the Sofia alone. Crossover to other thrombectomy devices occurred in 29.1% of cases (94/323). The median number of passes was 1 (IQR=1–3). Median time from puncture to recanalization was 26 min (IQR=17–45). Procedure related complications occurred in 3.1% (10/323) of cases. Conclusion Our study highlights the potential advantage of the Sofia aspiration catheter for primary aspiration thrombectomy in acute ischemic stroke. High rates of first pass recanalization with low crossover rates to other thrombectomy devices were achieved. Median procedure time was low, as were procedural complications.

Abstract Background Flow diversion is a common endovascular treatment for cerebral aneurysms, but studies comparing different types of flow diverters are scarce. Objective To perform a propensity score matched cohort study comparing the Pipeline Embolization Device (PED) and Flow Redirection Intraluminal Device (FRED) for posterior circulation aneurysms. Methods Consecutive aneurysms of the posterior circulation treated at 25 neurovascular centers with either PED or FRED were collected. Propensity score matching was used to control for age, duration of follow-up imaging, adjunctive coiling, and aneurysm location, size, and morphology; previously ruptured aneurysms were excluded. The two devices were compared for the following outcomes: procedural complications, aneurysm occlusion, and functional outcome. Results A total of 375 aneurysms of the posterior circulation were treated in 369 patients. The PED was used in 285 (77.2%) and FRED in 84 (22.8%) procedures. Aneurysms treated with the PED were more commonly fusiform and larger than those treated with FRED. To account for these important differences, propensity score matching was performed resulting in 33 PED and FRED unruptured aneurysm pairs. No differences were found in occlusion status and neurologic thromboembolic or hemorrhagic complications between the two devices. The proportion of patients with favorable functional outcome was higher with FRED (100% vs 87.9%, p=0.04). Conclusion Comparative analysis of PED and FRED for the treatment of unruptured posterior circulation aneurysms did not identify significant differences in aneurysm occlusion or neurologic complications. Variations in functional outcomes warrant additional investigations.

Abstract BACKGROUND The Pipeline Embolization Device (PED; Medtronic) has been used off-label for the treatment of challenging posterior circulation aneurysms. Data on this modality are primarily limited to small retrospective single-center series. OBJECTIVE To assess safety and efficacy of this treatment by establishing an international, multicenter collaboration. METHODS Consecutive posterior circulation aneurysms treated with the PED from 2012 to 2019 across 11 neurovascular centers were retrospectively reviewed. Baseline demographics, aneurysm and treatment characteristics, complications, occlusion status, and functional outcome were assessed. RESULTS There were 149 posterior circulation aneurysms treated with PED in 146 patients. A total of 24 (16.4%) patients presented with subarachnoid hemorrhage. Most aneurysms were dissecting/blister (36.2%) in morphology, followed by saccular (35.6%) and fusiform (28.2%). The most common locations were the vertebral (51.7%) and basilar arteries (22.8%). Complete or near-complete occlusion (>90%) was achieved in 90.9% of aneurysms at a median follow-up of 12 mo. Dissecting/blister aneurysms were most likely to occlude ( P = .06). Symptomatic neurologic complications occurred in 9.4% of aneurysms, associated with larger size, ruptured presentation, presentations with brain stem compression, cranial nerve palsy, or stroke. Favorable functional outcome (modified Rankin Score 0-2) was achieved in 86.2% of patients. There were 6 fatalities of which 4 occurred in aneurysmal subarachnoid hemorrhage patients. CONCLUSION This multicenter study shows that PED for the treatment of posterior circulation is preferentially used for the treatment of fusiform and dissecting/blister aneurysm morphologies. Despite the challenges presented by these less-common morphologies, flow diversion may be performed with a neurologic complication rate of about 10% and favorable long-term aneurysm occlusion rates.

ABSTRACTBACKGROUND AND PURPOSEThere is a relative paucity of radiology literature on spinal cord cavernous malformations (SCMs). We hypothesized that the classic MRI features of cavernous malformations are not highly prevalent. The purpose was to review MR imaging findings of SCMs with a focus on prevalence of hemorrhagic features, including adjacent intramedullary hemorrhage at initial presentation.METHODSIn this single‐institution study, 78 SCMs in 76 patients diagnosed on imaging/pathology were retrospectively evaluated for size, location, cord expansion, exophytic component, popcorn morphology, signal characteristics, including T1 weighted (T1w) and T2w rims, blood‐fluid levels, and adjacent intramedullary hemorrhage. Intramedullary hemorrhage was defined as centrally and/or eccentrically located linear or flame shaped non‐edematous signal abnormality extending longitudinally away from SCMs, distinct from lesional rim.RESULTSSixty‐three percent (49/78) of SCMs measured <1 cm in length, 78% (61/78) extended to the cord surface, 65% (51/78) were expansile, and 32% (25/78) were exophytic. Popcorn morphology was seen in 15% (12/78) on T1w and 22% (17/78) on T2w. Internal blood‐fluid levels were evident in 4% (3/78). Sixty‐nine percent (54/78) showed T2w hypointense rims; the T2w rim was complete/near‐complete in 37% (29/78). A rim on T1w was visible in 49% (38/78); this was hyperintense in 58% (22/38). Adjacent intramedullary hemorrhage was seen in 45/78 (58%), was most commonly bidirectional in 67% (30/45) and eccentric in 68% (30/44). Cord edema was seen in 22% (17/78); 53% (9/17) also demonstrated intramedullary hemorrhage with edema.CONCLUSIONSThe classically described popcorn morphology, internal blood‐fluid levels, and complete/near‐complete T2w hypointense rims are often absent on MRIs in SCMs. Adjacent intramedullary hemorrhage is frequently present, often eccentric and bidirectional.

AbstractThe extracranial and intracranial circulations are richly interconnected at numerous locations, a functional connectivity which underlies their impressive capacity for adaptive plasticity in the setting of vasoocclusive disease. While evolutionarily beneficial, these connections can also result in inadvertent communication with the intracranial circulation during embolization of extracranial vessels, potentially resulting in stroke or cranial nerve palsy. While these anastomoses are always present to a certain extent, flow through them occurs under predictable circumstances, and thus embolization of the extracranial vasculature can be performed safely when knowledge of functional anatomy is combined with adherence to basic principles. Herein, we will review the anatomy of known extracranial–intracranial anastomoses and strategies for avoidance of unwanted intracranial embolization. We will also review the vascular supply to cranial nerves most at risk during common neurointerventional procedures, as well as blood supply to mucosal structures.

Endovascular intervention for acute ischaemic stroke care is mostly performed in older patients, often with unfavourable aortic and supra-aortic anatomy, as well as cardiovascular comorbidities. A significant subset of them may benefit from transcervical access as the initial approach for mechanical thrombectomy. In fact, direct carotid artery puncture in these cases has the advantage to bypass the anatomical obstacles and achieve faster reperfusion. Caution is advised when common carotid artery access is pursued in order to avoid adverse events, including haematoma formation, iatrogenic arterial dissection and sheath kinking. In spite of potential complications, direct carotid puncture in acute ischaemic stroke intervention overcomes challenging angioarchitecture and may reduce the rate of poor clinical outcomes associated with delayed revascularisation in certain cases.