Miller Fisher's Rules and Digital Health: The Best of Both Worlds.

Background Professor Fisher's legacy, defined by meticulous observation, curiosity, and profound knowledge, has established a foundational cornerstone in medical practice. However, the advent of automated algorithms and artificial intelligence in medicine raises questions about the applicability of Fisher's principles in this era. Our objective is to propose adaptations to these enduring rules, addressing the challenges and leveraging the opportunities presented by digital health. Summary The adapted rules we propose advocate for the harmonious integration of traditional bedside manners with contemporary technological advancements. The judicious use of advanced devices for patient examination, recording, and sharing, while upholding patient confidentiality, is pivotal in modern practice and academic research. Additionally, the strategic employment of AI tools at the bedside, to aid in diagnosis and hypothesis generation, underscores their role as valued complements to clinical reasoning. These adapted rules emphasize the importance of continual learning from experience, literature, and colleagues, and stress the necessity for a critical approach towards AI-derived information, which further consolidates clinical skills. These aspects underscore the perpetual relevance of Professor Fisher's rules, advocating not for their replacement but for their evolution. Thus, a balanced methodology that adeptly utilizes the strengths of AI and digital tools, while steadfastly maintaining the core humanistic values, arises as essential in the modern practice of medicine. Key Messages A commitment between traditional medical wisdom and modern technological capabilities may enhance medical practice and patient care. This represents the future of medicine - a resolute commitment to progress and technology, while preserving the essence of medical humanities.

Advances in Prehospital Management of Intracerebral Hemorrhage.

BACKGROUND: Spontaneous acute intracerebral hemorrhage (ICH) is associated with greater stroke-related disability and mortality. Hematoma expansion (HME), an important treatment target in acute ICH, is time-dependent, with a greater probability of hematoma growth occurring <3 hours from ICH onset. SUMMARY: Promising treatment options to reduce HME include early intensive blood pressure (BP) reduction and the administration of hemostatic or anticoagulant reversal agents, yet large phase III clinical trials have so far failed to show overwhelming benefit for these interventions in acute ICH. Post-hoc analyses provide evidence, however, that the therapeutic benefit of such treatments is enhanced by rapid and ultra-early intervention, likely driven in large part by attenuation of early HME. Clinical trials assessing ultra-rapid treatments (<2 hours from ICH onset), including study procedures in the ambulance setting are currently underway, and demonstrate that the prehospital phase is a critical window for ICH management and an indispensable area of ICH research. Mobile stroke units, specialized ambulances equipped with imaging capabilities can provide confirmatory diagnosis and expedite treatments, as in acute ischemic stroke. Nevertheless, multiple barriers (financial, organisational, geographical among others) hinder worldwide implementation. Emerging portable technologies as well as point-of-care measures of blood biomarkers show promise as feasible adjunct tools to discriminate ICH from AIS in the field and have the potential for widespread accessibility. KEY MESSAGES: Ultra-early interventions in acute ICH are likely necessary to mitigate the risk of HME, and as such, the prehospital setting is ideal to initiate time-sensitive ICH therapies. As such, reliable prehospital acute ICH detection is essential to provide disease-specific treatments. Overall, it is imperative that "Time is brain" become the mantra not only for ischemic stroke but for ICH as well, and that the promise of ultra-early therapies for ICH be translated into concrete benefits for patients with this devastating condition.

Simultaneous multiple cervical vessel dissection manifested as pulsatile tinnitus.

A previously healthy 43-year-old woman with Wallenberg syndrome, stemming from a left vertebral artery dissection and resulting in a left lateral medulla oblongata infarct, was later diagnosed with simultaneous bi-carotid and right V3 dissection. Seven days post-admission, she experienced sudden right-sided pulsatile tinnitus and exhibited a right-sided carotid murmur. High-resolution vessel wall MR imaging confirmed the new dissections. While spontaneous cervical vessel dissections involving more than two arteries are rare (less than 2% of cases), the prognosis is generally favorable. This case is noteworthy for presenting pulsatile tinnitus as a rare post-stroke dissection recurrence symptom, as documented in medical literature.

RapidpulseTM cyclic aspiration system for acute ischemic stroke due to large vessel occlusions.

BACKGROUND: The best strategy to achieve optimal reperfusion outcomes during mechanical thrombectomy remains to be defined. The RapidPulseTM Cyclic Aspiration System is a novel technology, delivering high-frequency pulsed vacuum forces to increase the efficiency of aspiration thrombectomy. METHODS: Prospective, multicenter, open-label, core lab-adjudicated, two-arm study comparing safety and efficacy of a feasibility version of the RapidPulseTM system compared with contemporary controls. Primary endpoint was the rate of mTICI ≥ 2c after first-pass effect (FPE). Additional efficacy endpoints were the rates of mTICI ≥ 2b after first pass (modified FPE (mFPE)), last pass with study device defined as frontline technical success, and after all passes including rescue therapy. The primary safety endpoints included symptomatic ICH (sICH) within 24 h post-procedure. RESULTS: Between February 2022 to December 2022, 80 subjects were consented and enrolled in the study (n = 40 treatment arm, n = 40 control arm). In the intent to treat (ITT) population, mean age was 67.8 ± 11.5 years; 19 (47.5%) were male. Median NIHSS score was 16 (IQR: 13-22). Median ASPECTS score was 9 (IQR: 8-10). The rate of mTICI ≥ 2c after first pass was 53.9% in ITT population (60.0% in per-protocol population) versus 38.5% in the corresponding control population. Functional independence (mRS 0-2) at 90 days was achieved in 61.1% (22/36) in the RapidPulseTM arm and 52.8% (19/36) in the control arm. In the RapidPulseTM arm, no sICH within 24 h and no device-related morbidity or mortality occurred. CONCLUSION: Preliminary data suggests RapidPulseTM Aspiration System is highly effective and safe for recanalization of large vessel occlusions.

Percutaneous treatment of an intraorbital arteriovenous malformation using a transvenous approach: A case report.

Intraorbital arteriovenous malformations (AVMs) are extremely rare, and their actual prevalence is unknown. There is no consensus regarding the best treatment options, and the treatment is usually challenging, involving endovascular and other surgical procedures. Herein, we report the case of a patient diagnosed with an intraorbital AVM, presenting with thrombosis and hemorrhage, with rapidly progressive proptosis, chemosis, ophthalmoparesis, and vision loss. Treatment was performed with a transorbital puncture targeting a venous aneurysm of the superior ophthalmic vein, and closure of the AVM was possible with the use of coils and Onyx. We obtained anatomical occlusion of the lesion, and the patient showed progressive improvement of chemosis, vision acuity, and ophthalmoparesis. At six-month' follow-up, only mild proptosis was noted, and a control digital subtraction angiography confirmed complete closure of the AVM, with no residual lesion. To date, this is the first case of an intraorbital AVM treated with transorbital direct puncture.

Transvenous embolization of brain arteriovenous malformations: a review of techniques, indications, and outcomes.

Endovascular embolization of brain arteriovenous malformations (AVMs) is conventionally performed from a transarterial approach. Transarterial AVM embolization can be a standalone treatment or, more commonly, used as a neoadjuvant therapy prior to microsurgery or stereotactic radiosurgery. In contrast to the transarterial approach, curative embolization of AVMs may be more readily achieved from a transvenous approach. Transvenous embolization is considered a salvage therapy in contemporary AVM management. Proposed indications for this approach include a small (diameter < 3 cm) and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries. Available studies of transvenous AVM embolization in the literature have reported high complete obliteration rates, with reasonably low complication rates. However, evaluating the efficacy and safety of this approach is challenging due to the limited number of published cases. In this review the authors describe the technical considerations, indications, and outcomes of transvenous AVM embolization.

Schistosomal Cervical Myelopathy

Schistosomiasis is an infectious disease caused by trematode platyhelminths of the genus Schistosoma. The involvement of the cervical spinal cord is rare, with few cases reported in the literature. The management of such patients is particularly challenging, since clinical and radiological findings may be confounded with other inflammatory diseases and/ or spinal cord tumors. We describe a 20-year old male with a history of swimming outdoors. He first presented pain in the back of the neck extending to shoulders and upper limbs paresis associated with four limbs hyperreflexia. The magnetic resonance imaging (MRI) showed a hypointense T1-weighted lesion in the cervical spinal cord, which was hyperintense on T2 images. The serologic testing was negative for schistosomiasis. A cervical cord biopsy at the C5-C6 level showed Schistosoma eggs in the histopathological examination. The treatment was performed using a single dose of praziquantel 50 mg/kg, with prednisone 40 mg/day for 3 weeks. On the follow-up, 1 year later, the patient presented mild reduction of the vibratory sensitivity in the distal third of both legs. Our illustrative case strengthens that, in endemic regions, Schistosoma mansoni infestation should be included in the differential diagnosis of intramedullary expansive lesions.

A esquistossomose é uma doença infecciosa causada por platelmintos trematódeos do gênero Schistosoma. O acometimento da medula espinhal cervical é raro, com poucos casos apresentados na literatura. O manejo desses pacientes é particularmente difícil, uma vez que os achados clínicos e radiológicos podem ser confundidos com outras doenças inflamatórias e/ou tumores da medula espinhal. Descrevemos um homem de 20 anos de idade com história de natação ao ar livre. Primeiramente, ele apresentou cervicalgia que se estendeu até os ombros e paresia dos membros superiores, associada à hiperreflexia de quatro membros. A ressonância magnética (RM) mostrou lesão hipointensa em T1 na medula espinhal cervical, a qual foi hiperintensa nas imagens em T2. O teste sorológico foi negativo para esquistossomose. Uma biópsia da medula cervical ao nível C5-C6 evidenciou ovos de Schistosoma no exame histopatológico. O tratamento foi realizado com dose única de praziquantel 50 mg/ kg, com prednisona 40 mg/dia por 3 semanas. No seguimento de 1 ano, o paciente apresentou discreta redução da sensibilidade vibratória no terço distal de ambas as pernas. Nosso caso ilustrativo reforça que, em regiões endêmicas, a infestação pelo Schistosoma mansoni deve ser incluída no diagnóstico diferencial de lesões expansivas intramedulares.

Influence of Anatomic Changes on the Outcomes of Carotid Siphon Aneurysms After Deployment of Flow-Diverter Stents.

BACKGROUND: Flow-diverter stent (FDS) deployment can cause morphological and hemodynamic changes in the carotid siphon (CS), influencing the occlusion rate of aneurysms in this location. OBJECTIVE: To evaluate morphological changes to the CS after FDS deployment and their relationship with the rate of occlusion of intracranial aneurysms. METHODS: A cohort of 183 patients with CS aneurysms were treated by deployment of Pipeline® FDS (Medtronic Inc, Dublin, Ireland). Their CSs were classified as type U, V, C, or S, depending on morphology. The posterior and anterior bend angles were measured on strict lateral cerebral angiogram with digital subtraction before FDS deployment, immediately after deployment, and at 6 mo. Differences between angles were analyzed to identify any correlations with rates of aneurysm occlusion, using the O'Kelly-Marotta classification. RESULTS: FDS deployment was associated with immediate changes in CS morphology. The mean anterior angle increased from 3.97 ± 25.06° to 22.05 ± 25.18° (P < .001) and the mean posterior angle increased from 71.98 ± 31.27° to 79.43 ± 31.80° (P < .001). Multivariate analysis revealed a progressive, statistically significant increase in frequency of complete (grade D) occlusion at 6-mo follow-up with increasing anterior bend angle (prevalence ratios (PR) = 1.42 for increases between 5.3° and 12°, P = .017; PR = 1.56 for increases between 12.1° and 27.6°, P = .002; PR = 1.83 for increases >27.6°, P < .001, all vs increases <5.3°). CONCLUSION: FDS deployment induces changes in CS morphology. Specifically, increases in mean anterior angle are associated with better radiological results on 6-mo follow-up digital subtraction angiography.

Transvenous Curative Embolization of Cerebral Arteriovenous Malformations: A Prospective Cohort Study.

BACKGROUND: Curative transvenous embolization is an emerging strategy for treatment of cerebral arteriovenous malformations (AVMs). OBJECTIVE: To assess contemporary outcomes of transvenous embolization as a stand-alone therapy for cerebral AVMs. METHODS: We prospectively followed 40 patients with 41 AVMs who underwent transvenous endovascular therapy between January 2008 and January 2015. Patient demographics, AVM characteristics, endovascular techniques used, angiographic results, clinical outcomes, and complications were assessed independently. RESULTS: Thirty-eight of 41 (92.6%) AVMs were anatomically cured. The mean patient age was 37.7 yr (range, 18-69 yr) and 55% were female. Twenty-seven (67.5%) patients presented with hemorrhage. The mean size of the AVM nidus was 2.8 ± 1.2 cm, and low Spetzler-Martin grade AVMs comprised 41.5% of lesions. The majority of patients were treated in 1 session (56%; n = 23). The mean follow-up period was 28.4 (range, 6-106 mo). There was 1 (2.5%) hemorrhagic complication related to microcatheter navigation and 1 (2.5%) venous infarction was observed without clinical consequences. At 6-mo follow-up, 1 (2.5%) patient had significant disability. There were no recurrences during the follow-up period. Overall mortality was 2.5% and procedure-related mortality was 0%. CONCLUSION: This prospective contemporary series demonstrates a high rate of complete AVM obliteration and excellent functional outcomes in patients with both ruptured and unruptured AVMs treated with transvenous embolization. This approach is promising and warrants further investigation as a treatment for select AVMs.

Evaluation of ischemic lesion prevalence after endovascular treatment of intracranial aneurysms, as documented by 3-T diffusion-weighted imaging: a 2-year, single-center cohort study.

OBJECTIVE Even though published data exist concerning the prevalence of ischemic lesions detected by diffusion-weighted imaging (DWI) following endovascular treatment of intracranial aneurysms, a single-center cross-evaluation of the different endovascular techniques has been lacking. The authors sought to prospectively evaluate the prevalence and clinical significance of ischemic lesions occurring after endovascular treatment of intracranial aneurysms and to compare the safety and effectiveness of a broad spectrum of currently accepted endovascular techniques in a single-center setting. METHODS This was a prospective cohort study involving consecutive patients treated for intracranial aneurysms exclusively by endovascular means, excluding treatments in the acute rupture phase, in a center featuring an endovascular-only treatment policy for intracranial aneurysms. All patients underwent MRI, including a 3-directional DWI sequence, before treatment, 24 hours postprocedure, and 6 months following endovascular embolization. Selective angiography was performed at 6 months' follow-up. RESULTS From January 2012 through December 2013, 164 aneurysms were treated in 128 consecutive patients. Endovascular techniques included coiling (14.6%), balloon-assisted coiling (20.1%), stent-assisted coiling (3.7%), low-profile stent-assisted coiling, flow diversion (38.4%), and very complex treatments (6.1%) involving 2 stents in Y or T configurations. On postprocedure MRI, the rates of occurrence of new DWI-positive lesions were 64.3% for coiling, 54.5% for remodeling, 61.1% for stent-assisted coiling, 53.7% for flow-diverting stents, and 75% for very complex treatments (p = 0.4962). The 6-month procedure-related morbidity and mortality rates were 6.25% and 0%, respectively. At 6 months' follow-up, 93% of the patients had modified Rankin Scale (mRS) scores of 0-2. Very complex treatments offered a higher complete occlusion rate (100%) than all other techniques (66.7%-88.9%). Age and length of procedure were independent factors for DWI lesion occurrence. The diameter of DWI lesions on 24-hour postprocedure MRI was positively correlated with mRS score at discharge. Among the DWI-positive lesions measuring less than 2 mm in diameter on the 24-hour MRI, 44.12% had regressed at 6 months. CONCLUSIONS Procedure-related DWI lesions are far more often encountered in silent forms than they are clinically evident. They do not seem to be significantly correlated with procedure-related complications, nor do they seem to impair clinical outcome, regardless of the endovascular technique. Small lesions (< 2 mm in diameter) may regress within 6 months. The use of the most adapted technique, in terms of aneurysm configuration, results in significant total occlusion rates, with acceptable safety.

Endoscopic Submandibular Retropharyngeal Approach to the Craniocervical Junction and Clivus: an Anatomic Study.

INTRODUCTION: Surgery of the craniocervical junction (CCJ) and clivus is technically demanding. For many years, we have used the submandibular retropharyngeal approach for surgery of the upper cervical spine, especially hangman fracture. We hypothesized that submandibular gland resection could offer a significant cranial enlargement of the operative field, up to the clivus. Our aim in this work was to assess the feasibility of an endoscope-assisted retropharyngeal approach to the CCJ and clivus. METHODS: Eight anatomic specimens were used, including 4 silicon-injected specimens. We performed a submandibular retropharyngeal approach with gland resection, and then we exposed the CCJ and clivus. We drilled the C2 vertebral body, odontoid process, C1 anterior arch, and the clivus. We noted 8 anatomic landmarks that were easily identified on each anatomic specimen. These measurements were designed to quantify the exposure of the clivus and CCJ after bone resection. RESULTS: A submandibular approach was feasible in all specimens. The main dimensions of the area of dural exposure after bone drilling were as follows: mean width between C1 lateral masses, 19 mm (range, 17-20 mm); at the tip of the clival window, 18 mm (range, 16-20 mm); distance between the C3 vertebra and the tip of the window within the clivus, 57 mm (range, 55-60 mm). CONCLUSIONS: An endoscopic submandibular retropharyngeal approach provides a simple and straightforward access to the CCJ. It also conveniently exposes the clivus. This technique could be added to the techniques used for this difficult surgery.

Far-Lateral Approach Without Drilling the Occipital Condyle for Vertebral Artery-Posterior Inferior Cerebellar Artery Aneurysms.

BACKGROUND: The far-lateral transcondylar surgical approach is often used to clip vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms. The role of condyle resection during this approach is controversial. OBJECTIVE: To evaluate patient outcomes in patients with VA-PICA aneurysms in whom drilling the occipital condyle was not necessary. METHODS: Between May 2005 and December 2012, a total of 56 consecutive patients with incidental or ruptured VA-PICA aneurysms underwent surgery with a far-lateral approach without condylar resection. Clinical presentation, surgical reports, presurgery and postsurgery radiological examinations, and clinical follow-up reports were assessed. Anatomic aneurysm location was analyzed through angiography or computed tomography angiography. We compared postsurgical Glasgow Outcome Scale scores, modified Rankin Scale scores, and morbidity in 2 groups: those with aneurysms in the anterior medullary segment and those with aneurysms in the lateral medullary segment. RESULTS: The predominant presentation was subarachnoid hemorrhage in 34 patients (60.7%). Most aneurysms (n = 27 [48.2%]) were located in the lateral medullary segment of the PICA, followed by the anterior medullary segment (n = 25 [44.6%]). Total aneurysm occlusion was achieved in 100% of patients, and bypass techniques were necessary in 3 patients (5.4%). Fifty-two patients (92.8%) had Glasgow Outcome Scale scores of 4 or 5 postsurgery. CONCLUSIONS: A far-lateral approach that leaves the occipital condyle intact is adequate for treating most patients with VA-PICA aneurysms.

Role of terminal and anastomotic circulation in the patency of arteries jailed by flow-diverting stents: from hemodynamic changes to ostia surface modifications.

OBJECTIVE The outcome for jailing arterial branches that emerge near intracranial aneurysms during flow-diverting stent (FDS) deployment remains controversial. In this animal study, the authors aimed to elucidate the role of collateral supply with regard to the hemodynamic changes and neointimal modifications that occur from jailing arteries with FDSs. To serve this purpose, the authors sought to quantify 1) the hemodynamic changes that occur at the jailed arterial branches immediately after stent placement and 2) the ostia surface values at 3 months after stenting; both parameters were investigated in the presence or absence of collateral arterial flow. METHODS After an a priori power analysis, 2 groups (Group A and Group B) were created according to an animal flow model for terminal and anastomotic arterial circulation; each group contained 7 Large White swine. Group A animals possessed an anastomotic-type arterial configuration to supply the territory of the right ascending pharyngeal artery (APhA), while Group B animals possessed a terminal-type arterial configuration to supply the right APhA territory. Subsequently, all animals underwent FDS placement, thereby jailing the right APhAs. Mean flow rates and velocities inside the jailed branches were quantified using time-resolved 3D phase-contrast MR angiography before and after stenting. Three months after stent placement, the jailed ostia surface values were quantified on scanning electron micrographs. The data were analyzed using descriptive statistics and group comparisons with parametric and nonparametric tests. RESULTS The endovascular procedures were feasible, and there were no findings of in situ thrombus formation on postprocedural optical coherence tomography or ischemia on postprocedural diffusion-weighted imaging. In Group A, the mean flow rate values at the jailed right APhAs were reduced immediately following stent placement as compared with values obtained before stent placement (p = 0.02, power: 0.8). In contrast, the mean poststenting flow rates for Group B remained similar to those obtained before stent placement. Three months after stent placement, the mean ostia surface values were significantly higher for Group B (527,911 ± 306,229 µm2) than for Group A (89,329 ± 59,762 µm2; p < 0.01, power: 1.00), even though the initial dimensions of the jailed ostia were similar between groups. A statistically significant correlation was found between groups (A or B), mean flow rates after stent placement, and ostia surface values at 3 months. CONCLUSIONS When an important collateral supply was present, the jailing of side arteries with flow diverters resulted in an immediate and significant reduction in the flow rate inside these arteries as compared with the prestenting values. In contrast, when competitive flow was absent, jailing did not result in significant flow rate reductions inside the jailed arteries. Ostium surface values at 3 months after stent placement were significantly higher in the terminal group of jailed arteries (Group B) than in the anastomotic group (Group A) and strongly correlated with poststenting reductions in the velocity value.

Biomechanics of transvertebral screw fixation in the thoracic spine: an in vitro study.

OBJECTIVE Transvertebral screws provide stability in thoracic spinal fixation surgeries, with their use mainly limited to patients who require a pedicle screw salvage technique. However, the biomechanical impact of transvertebral screws alone, when they are inserted across 2 vertebral bodies, has not been studied. In this study, the authors assessed the stability offered by a transvertebral screw construct for posterior instrumentation and compared its biomechanical performance to that of standard bilateral pedicle screw and rod (PSR) fixation. METHODS Fourteen fresh human cadaveric thoracic spine segments from T-6 to T-11 were divided into 2 groups with similar ages and bone quality. Group 1 received transvertebral screws across 2 levels without rods and subsequently with interconnecting bilateral rods at 3 levels (T8-10). Group 2 received bilateral PSR fixation and were sequentially tested with interconnecting rods at T7-8 and T9-10, at T8-9, and at T8-10. Flexibility tests were performed on intact and instrumented specimens in both groups. Presurgical and postsurgical O-arm 3D images were obtained to verify screw placement. RESULTS The mean range of motion (ROM) per motion segment with transvertebral screws spanning 2 levels compared with the intact condition was 66% of the mean intact ROM during flexion-extension (p = 0.013), 69% during lateral bending (p = 0.015), and 47% during axial rotation (p < 0.001). The mean ROM per motion segment with PSR spanning 2 levels compared with the intact condition was 38% of the mean intact ROM during flexion-extension (p < 0.001), 57% during lateral bending (p = 0.007), and 27% during axial rotation (p < 0.001). Adding bilateral rods to the 3 levels with transvertebral screws decreased the mean ROM per motion segment to 28% of intact ROM during flexion-extension (p < 0.001), 37% during lateral bending (p < 0.001), and 30% during axial rotation (p < 0.001). The mean ROM per motion segment for PSR spanning 3 levels was 21% of intact ROM during flexion-extension (p < 0.001), 33% during lateral bending (p < 0.001), and 22% during axial rotation (p < 0.001). CONCLUSIONS Biomechanically, fixation with a novel technique in the thoracic spine involving transvertebral screws showed restoration of stability to well within the stability provided by PSR fixation.

Transvenous Embolization in Pediatric Plexiform Arteriovenous Malformations.

BACKGROUND: Transvenous embolization is a developing concept for curative therapy of cerebral arteriovenous malformations (AVMs). The feasibility of this endovascular method has not been reported in children. OBJECTIVE: To report our experience treating pediatric AVMs with the transvenous approach (TVA). METHODS: A cohort of 7 pediatric patients (younger than 18 years of age) who underwent the TVA for cerebral AVMs between January 2012 and January 2014. The TVA was used alone or in conjunction with other arterial approaches in definitive embolization sessions. Patient demographics, AVM characteristics, clinical outcomes, and angiographic results were independently assessed. Pial arteriovenous fistulae and vein of Galen malformations were excluded. Control angiograms were obtained at 6 months, and curative treatment was determined by the anatomic obliteration of the nidus. RESULTS: All patients had anatomic exclusion of the AVM. The mean size was 2 ± 0.6 cm, and hemorrhage was the most common presentation (100%, n = 7). Most AVMs were deeply placed (71%, n = 5), and a proximal approach to the nidus was achieved in all cases. Transvenous embolization alone was performed in 3 patients (43%), whereas combined arterial and venous embolization was required in 4 patients (57%). The mean follow-up period was 20.2 ± 10.5 months. There were no hemorrhagic or thromboembolic events, and venous infarction was not documented. No recurrence was documented. CONCLUSION: This is the first report that demonstrates the feasibility of transvenous Onyx embolization of AVMs in the pediatric population. Such a technique may be considered in certain AVMs that meet anatomic criteria in which microsurgery and radiosurgery might not be indicated.

Endovascular Management of Deep Arteriovenous Malformations: Single Institution Experience in 22 Consecutive Patients.

BACKGROUND: The management of arteriovenous malformations (AVMs) in the basal ganglia, insula, and thalamus is demanding for all treatment modalities. OBJECTIVE: To define safety and outcomes of embolization used as a stand-alone therapy for deep-seated AVMs. METHODS: A cohort of 22 patients with AVMs located in the basal ganglia, thalamus, and insula who underwent embolization between January 2008 and December 2013. RESULTS: Eighteen of 22 (82%) patients had anatomic exclusion. The mean size was 2.98 ± 1.28 cm, and the mean number of sessions was 2.1 per patient. Most patients presented with hemorrhage (82%, n = 18), and 3 (14%) patients were in a deteriorated neurological status (modified Rankin Scale >2) at presentation. Sixty-eight percent of ruptured AVMs had size ≤3 cm. A single transarterial approach was performed in 9 (41%) cases, double catheterization was used in 4 (18%), and the transvenous approach was required in 8 (36%) cases. Procedure-related complications were registered in 3 (14%) cases. One death was associated with treatment, and complementary radiosurgery was required in 2 (9%) patients. CONCLUSION: Embolization therapy appears to be safe and potentially curative for certain deep AVMs. Our results demonstrate a high percentage of anatomic obliteration with rates of complications that may approach radiosurgery profile. In particular, embolization as stand-alone therapy is most suitable to deep AVMs with small nidus size (≤3 cm) and/or associated with single venous drainage in which microsurgery might not be indicated.

Retrograde leptomeningeal venous approach for dural arteriovenous fistulas at foramen magnum.

A 72-year-old man presented with sudden right homonymous hemianopsia. Work-up imaging revealed a left occipital haematoma and an arteriovenous fistula supplied by the meningeal branches to the clivus from the left vertebral artery (VA) with a rostral venous reflux into cortical veins. A microcatheter was advanced through brainstem veins into the venous collector. A compliant balloon was placed in the left VA facing the origin of feeders. The balloon was inflated to protect the vertebrobasilar circulation from embolic migration. Onyx was injected by the transvenous catheter. Control angiogram revealed exclusion of the lesion. Informed consent was obtained from the patient.

Balloon-assisted microcatheter navigation for AVM embolization: technical note.

Recurrent feeders may preclude a successful arterial catheterization of arteriovenous malformations (AVMs). In this paper, the authors report their experience with the use of a compliant balloon to assist the microcatheter navigation in AVMs supplied by feeders with recurrent configuration. Eight patients with AVMs supplied by recurrent feeders had unsuccessful microcatheter navigation after multiple attempts to catheterize the pedicle. A compliant balloon was inflated in the parent artery immediately after the origin of the feeder. The microcatheter was then advanced over the wire while the balloon provided support for the navigation. Distal access close to the nidus was achieved in all cases. Anatomical cure was documented in 75% cases. There were no arterial perforations or thromboembolic events. The described technique is a straightforward method for providing support to microcatheter navigation in certain cases of cerebral AVMs supplied by recurrent arterial feeders. This simple yet effective maneuver may enhance outcomes of AVM embolization by eliminating the need for excessive attempts of catheterization.

Endoscopic endonasal atlantoaxial transarticular screw fixation technique: an anatomical feasibility and biomechanical study.

OBJECT The primary disadvantage of the posterior cervical approach for atlantoaxial stabilization after odontoidectomy is that it is conducted as a second-stage procedure. The goal of the current study is to assess the surgical feasibility and biomechanical performance of an endoscopic endonasal surgical technique for C1-2 fixation that may eliminate the need for posterior fixation after odontoidectomy. METHODS The first step of the study was to perform endoscopic endonasal anatomical dissections of the craniovertebral junction in 10 silicone-injected fixed cadaveric heads to identify relevant anatomical landmarks. The second step was to perform a quantitative analysis using customized software in 10 reconstructed adult cervical spine CT scans to identify the optimal screw entry point and trajectory. The third step was biomechanical flexibility testing of the construct and comparison with the posterior C1-2 transarticular fixation in 14 human cadaveric specimens. RESULTS Adequate surgical exposure and identification of the key anatomical landmarks, such as C1-2 lateral masses, the C-1 anterior arch, and the odontoid process, were provided by the endonasal endoscopic approach in all specimens. Radiological analysis of anatomical detail suggested that the optimal screw entry point was on the anterior aspect of the C-1 lateral mass near the midpoint, and the screw trajectory was inferiorly and slightly laterally directed. The custommade angled instrumentation was crucial for screw placement. Biomechanical analysis suggested that anterior C1-2 fixation compared favorably to posterior fixation by limiting flexion-extension, axial rotation, and lateral bending (p > 0.3). CONCLUSIONS This is the first study that demonstrates the feasibility of an endoscopic endonasal technique for C1-2 fusion. This novel technique may have clinical utility by eliminating the need for a second-stage posterior fixation operation in certain patients undergoing odontoidectomy.