Natural course of partially embolized carotid-cavernous fistulas.

BACKGROUND AND PURPOSE: To present the first study analyzing the clinical and radiological course of carotid-cavernous fistulas (CCFs) following incomplete embolization. The study compares magnetic resonance angiography (MRA) to plain angiography (digital subtraction angiography [DSA]) and investigates the long-term ophthalmological impact of residual fistula. METHODS: Fistulas classified as partially embolized after the last endovascular treatment were prospectively followed with DSA, MRA, and ophthalmological examination. Both direct and indirect CCFs were included. RESULTS: Twenty-one CCFs were included in the study. Nine (43%) fistulas were direct and 12 (57%) were indirect. A favorable clinical outcome of modified Rankin scale ≤2 was recorded in 19 (90%) patients at the last follow-up. Postinterventional ophthalmologic examinations in 16 patients revealed no negative effects of residual fistulas; five remaining patients refused to undergo further examination. Spontaneous thrombosis and complete occlusion of the CCF were demonstrated in 90% of patients, with a mean time to occlusion of 5.7 ± 4.7 months. Fourteen (66%) patients completed the full imaging follow-up (MRA and DSA). In 21% of these cases, discrepancy between the two imaging modalities was observed-MRA failed to detect persistent fistulas identified by DSA. CONCLUSIONS: The goal of CCF treatment is safe and complete embolization. However, if adequate flow reduction is achieved, both direct and indirect CCFs tend to spontaneously thrombose. Residual flow does not result in ophthalmological deterioration until the fistula is completely closed. MRA may not be sufficiently sensitive to detect residues of fistulas including cortical venous drainage. Therefore, complete CCF closure should be confirmed through DSA.

Indications for alternative endovascular techniques in carotid-cavernous fistulas: A 20-year single-center experience.

BACKGROUND: While coiling is considered the standard treatment for carotid-cavernous fistulas (CCFs), studies demonstrating excellent results using new materials, especially flow diverter (FD) stents and liquid embolisates, are becoming more frequent. The indications and effectiveness of these alternative endovascular techniques remain unclear. METHODS: A total of 22 direct and 20 indirect CCFs were included in the study. These were further subdivided based on the embolic material used: coils versus FD stents for direct and coils versus liquid embolisates for indirect CCFs. The subgroups were subjected to statistical analysis. RESULTS: An angiographic cure was achieved in 88% of all CCFs, 93% of patients' experienced clinical improvement or remained stable. Direct CCFs were treated with coiling (41%) or with both coils and FD stents (55%). One (4%) patient with a direct CCF was treated with FD stent alone. Statistical analysis comparing these subgroups revealed a significantly higher complete occlusion rate immediately after treatment in the coiling subgroup (67% vs. 23%, p = 0.0409). The occlusion rates at the last follow-up were similar (89% vs. 85%). Indirect CCFs were treated with coiling (35%) or liquid embolisates (65%). All three periprocedural ischemic complications were recorded within the liquid subgroup, resulting in a significantly higher clinical deterioration rate (p = 0.0333). CONCLUSION: FD stents in direct and liquid embolisates in indirect fistulas did not demonstrate better angiographic or clinical outcomes compared to convetional coiling. Liquid agents carried a higher risk of ischemic complications. Alternative embolization materials should be reserved for CCFs that cannot be treated with simple coiling.

Copolymer liquid embolization of dural arteriovenous fistulas: A 20-year single-center experience.

BACKGROUND AND PURPOSE: Dural arteriovenous fistulas (DAVFs) with cortical venous drainage (CVD) carry significant risks of cerebral ischemia and intracranial hemorrhage. Endovascular treatment (EVT) using Onyx, a copolymer-based liquid embolic material, has become the preferred approach. However, the optimal treatment strategy for anterior cranial fossa DAVFs remains debated. METHODS: This retrospective study analyzed outcomes of EVT for DAVFs in a single center from 2002 to 2023. Patient data including demographics, clinical status, angiographic findings, embolization techniques, and outcomes were recorded. The results of the anterior fossa malformations were analyzed separately afterward. RESULTS: A total of 195 DAVFs were included in the study. The most common presenting symptom was hemorrhage (41%), most fistulas were located in the transverse and sigmoid sinus region (48%), and the majority of DAVFs had direct CVD (78%). Transarterial embolization with Onyx was the preferred treatment strategy in majority of cases (92%). Overall, 94% of patients showed improvement or stability on the modified Rankin Scale. Two patients died due to rebleeding after partial DAVF embolization. Onyx demonstrated higher immediate complete occlusion rate compared to other embolic materials (88% vs. 35%). Overall, 91% of fistulas were closed at the last follow-up. Ten anterior fossa DAVFs were treated, resulting in clinical improvement and complete occlusion in all cases. CONCLUSION: Based on the results of our study, we believe that a cure of DAVFs, including those in the anterior fossa, can be achieved in more than 90% of cases through transarterial Onyx embolization, given long-term clinical experience.

What is the most effective method to treat indirect carotid-cavernous fistula?

To review the most relevant treatment options for indirect carotid-cavernous fistulas (iCCF), cohorts of 20 patients or more published after 2000 were analyzed. Clinical and radiological outcomes, as well as embolization techniques and material, had to be clarified in the study to be considered. Statistical analysis was based on calculating the relative percentage of therapeutic methods or embolic material, followed by calculating parametric and nonparametric correlations. Some 22 studies and 1550 patients were included. Transvenous embolization (TVE) was used in 53% of the patients and was strongly associated with coiling (rw = 0.66, p = 0.0.0012; rs = 0.53, p = 0.0138), transarterial embolization (TAE) was preferred in 11% of the patients and was strongly linked to liquid embolics (rw = 0.44, p = 0.0434;rs = 0.64, p = 0.0018). A combination of TAE and TVE treatment was used in 7% and a combination of embolic materials in 13% of the patients. None of the endovascular techniques or embolization materials showed significant superiority over the others in clinical outcome and obliteration rate. Radiosurgery in 22% and mechanical compression in 5% of patients showed a lower obliteration rate (rw = - 0.48, p = 0.0254; rs = - 0.45, p = 0.0371). The clinical outcomes were comparable to endovascular treatment (EVT). The remaining 2% of the patients were treated by open surgery or a combination of EVT and radiosurgery. Transvenous coiling is the preferred EVT method for iCCF. However, comparable results may be accomplished with TAE using liquid. Radiosurgery may achieve a lower percentage of fistula occlusion, but the clinical results are equal to EVT.

Current trends and outcomes of non-elective neurosurgical care in Central Europe during the second year of the COVID-19 pandemic.

Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th-April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017-2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017-2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community´s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.

Intraoperative neurophysiological monitoring during urgent surgical extracranial internal carotid artery recanalization.

OBJECTIVE: The clinical outcome of surgical extracranial internal carotid artery (eICA) recanalization may be adversely affected by intraoperative ischemia. Median nerve somatosensory evoked potential (SEP) amplitude correlates well with cerebral blood flow. Our study presents the value of intraoperative SEP and selective shunting in the prevention of intraoperative ischemia development during urgent eICA recanalization. METHODS: Prospective recruitment of patients with acute unilateral eICA occlusion. All underwent surgical recanalization with intraoperative monitoring of scalp median SEPs. Preoperative clinical findings, cerebral collaterals, and 3 month functional outcome were evaluated. RESULTS: The cohort consisted of 33 patients. Intraoperative SEP amplitude decreased significantly in 6 (18.2%). An intraluminal shunt was inserted twice (6.1%), surgical complications occurred in 6 (18.2%), intracerebral hemorrhage was not found. Favorable outcome 3 months after surgery according to the modified Rankin scale (mRS 0-2) was achieved in 28 (84.8%), 3 patients died (9.1%). CONCLUSIONS: Intraoperative SEP during urgent eICA recanalization seems to be beneficial. Thanks to the effective measure based on the intraoperative SEP changes, the clinical outcome in four(12.1%) could be positively affected. SIGNIFICANCE: The results suggest that selective shunting based on intraoperative median SEPs may prevent intraoperative ischemia and may improve overall outcome of urgent eICA recanalization.

Long-term stability of Onyx: is there any indication for repeated angiography after dural arteriovenous fistula embolization?

OBJECTIVE: The natural course of dural arteriovenous fistulas (DAVFs) is unfavorable. Transarterial embolization with Onyx is currently the therapeutic method of choice, although the long-term stability of Onyx has been questioned. The literature reports a significant difference in the recurrence rate after complete DAVF occlusion and lacks larger series with long-term follow-up. The authors present the largest series to date with a long-term follow-up to determine the stability of Onyx, prospectively comparing magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) as follow-up diagnostic methods. METHODS: Demographics, clinical symptomatology, length of follow-up, diagnostic methods, and angiographic findings of DAVFs were recorded and retrospectively evaluated in 112 patients. A prospective group of 15 patients with more than 5 years of follow-up after complete DAVF occlusion was established. All 15 patients in the prospective group underwent a clinical examination and MRA; 10 of these patients also underwent DSA. The recurrences and the correlation between the two diagnostic methods were evaluated. RESULTS: Among the 112 patients, 71 were men and 41 were women, with an average age of 60 years. Intracranial hemorrhage (40%) was the most common clinical presentation of DAVF. At the last follow-up, 73% of the patients experienced clinical improvement, 21% remained unchanged, and 6% worsened. Overall, 87.5% of the DAVFs were occluded entirely with endovascular treatment, and 93% of the DAVFs were classified as cured at the last follow-up (i.e., completely embolized DAVFs and DAVFs that thrombosed spontaneously or after Gamma Knife surgery). Two recurrences of DAVFs were recorded in the entire series. Both were first diagnosed by MRA and confirmed with DSA. The mean follow-up was 27.7 months. In the prospective group, a small asymptomatic recurrence was diagnosed. The mean follow-up of the prospective group was 96 months. CONCLUSIONS: Onyx is a stable embolic material, although recurrence of seemingly completely occluded DAVFs may develop because of postembolization hemodynamic changes that accentuate primarily graphically absent residual fistula. These residuals can be diagnosed with MRA at follow-up. The authors' data suggest that MRA could be sufficient as the follow-up diagnostic method after complete DAVF occlusion with Onyx. However, larger prospective studies on this topic are needed.

Histological Analysis of Carotid Plaques: The Predictors of Stroke Risk.

OBJECTIVES: The morphology and histological structure of the atherosclerotic plaque seem critical to its stability. Our study aimed to identify the epidemiological, morphological and histological parameters associated with stable and unstable plaques. MATERIALS AND METHODS: The study included 280 plaques harvested from 269 consecutive patients. Epidemiological and demographic data were recorded as well as the histological features of plaque, i.e. calcifications, myxoid changes, bleeding into plaque, presence of thrombus, inflammation, macrophages, giant cell reaction, siderophages, neovascularization and plaque ossification. All specimens were classified according to the American Heart Association (AHA). RESULTS: Monofactorial analysis identified three significant histological predictors for the symptomatic plaque: a plaque with a large necrotic core (odds ratio, OR=2.0, p = 0.03), thrombosis (OR=3.7, p = 0.01) and the formation of foamy macrophages (OR=2.0, p = 0.01). Multifactorial logistic regression revealed that the presence of foamy macrophages (OR=1.9, p = 0.03) and thrombosis (OR=3.5, p = 0.02) were significant predictors of symptomatic stenosis. Symptomatic plaques were significantly more frequently classified as AHA type VI than AHA type IV-V compared to asymptomatic ones (OR=1.8, p = 0.03). CONCLUSIONS: Our study shows that no single histological feature, except for the presence of foamy macrophages and thrombosis on the plaque, is predictive of plaque instability. Rather, a complex plaque structure (AHA type VI) is predictive of plaque instability. Our findings should be kept in mind during the assessment of non-invasive imaging and stroke risk estimation.

Trends and outcomes for non-elective neurosurgical procedures in Central Europe during the COVID-19 pandemic.

The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care. We aimed to determine the incidence and 30-day mortality rate of various non-elective neurosurgical procedures during the COVID-19 pandemic. A retrospective, multi-centre observational cohort study among neurosurgical centres within Austria, the Czech Republic, and Switzerland was performed. Incidence of neurosurgical emergencies and related 30-day mortality rates were determined for a period reflecting the peak pandemic of the first wave in all participating countries (i.e. March 16th-April 15th, 2020), and compared to the same period in prior years (2017, 2018, and 2019). A total of 4,752 emergency neurosurgical cases were reviewed over a 4-year period. In 2020, during the COVID-19 pandemic, there was a general decline in the incidence of non-elective neurosurgical cases, which was driven by a reduced number of traumatic brain injuries, spine conditions, and chronic subdural hematomas. Thirty-day mortality did not significantly increase overall or for any of the conditions examined during the peak of the pandemic. The neurosurgical community in these three European countries observed a decrease in the incidence of some neurosurgical emergencies with 30-day mortality rates comparable to previous years (2017-2019). Lower incidence of neurosurgical cases is likely related to restrictions placed on mobility within countries, but may also involve delayed patient presentation.

Spinal meningiomas: is Simpson grade II resection radical enough?

BACKGROUND: The optimal treatment for spinal meningioma is complete resection. The radicality of resection is the most important predictive factor for future tumor recurrence. Although clinical series dedicated to spinal meningiomas are relatively frequent, only a minimum of these defines the length of the required follow-up and difference in tumor recurrence in the context of Simpson grade I and II resection. Therefore, we propose reconsideration of surgical treatment and long-term follow-up based on a retrospective analysis of 84 patients who underwent Simpson grade II resection. METHODS: The study included 84 patients operated between 1998 and 2018. Clinical symptomatology, age, sex, risk of comorbidities, spinal level, duration of symptoms, surgical resection radicality, tumor recurrence, and complications associated with treatment were recorded and evaluated. RESULTS: We encountered the diagnosis of spinal meningioma considerably more often in women (81%) than in men (19%). The average age of all patients was 65 years. Most meningiomas were located in the thoracic spine (82%) while the rest (18%) were located in the cervical spine. The most common symptoms were motor deficit (80%) and sensation disorders (70%). Of the symptomatic patients, 71% clinically improved, 27% showed no change and 2% worsened postoperatively. The mean follow-up was 32 months (range 1-204). During this period, there was a 5% tumor recurrence rate. However, when we analyzed a subgroup of nine patients who were monitored for more than 6 years, tumor recurrence was diagnosed in 44%, all of whom were women (mean age 51 years). CONCLUSION: Our results indicate that tumor recurrence after Simpson II resection could be significantly higher than previously thought if the follow-up is long enough, especially in younger patients. This finding suggests we consider using radical Simpson grade I resection more frequently. The study also demonstrates that after spinal meningioma surgery the patients should be followed and monitored on a long-term basis.

First Case Report of Bilateral Spontaneous Otogenic Pneumocephalus.

BACKGROUND: Pneumocephalus is commonly associated with cranial trauma including surgical interventions. Spontaneous pneumocephalus on the other hand is a rare diagnosis. Reported cases were predominantly unilateral. We report a unique case of a bilateral spontaneous pneumocephalus probably related to a bilateral tegmen defect related to repeated Politzer maneuvers. CASE DESCRIPTION: A 78-year-old man suffered from vertigo, tinnitus, instability, and mild expressive aphasia. In the past 12 weeks before clinical deterioration he underwent series of Politzer maneuvers performed for repetitive inflammation of upper respiratory tract with otitis media. Brain computed tomography revealed a large bilateral collection of intracranial air with associated tegmen defects. Primarily, surgical revision of the middle fossa and multilayer reconstruction of the dura and skull base defect on the left side was performed. After 5 days, the other side was reconstructed in a similar way. Postoperative course was uneventful with brisk improvement of symptomatology. Both computed tomography scans undertaken after the first and second surgery showed satisfying regression of intracranial air. CONCLUSIONS: Spontaneous pneumocephalus represents a rare condition often associated with increased middle ear pressure, which can be caused by autoinflation (e.g., Valsalva or Politzer maneuver), sneezing, or coughing. The described case represents a unique presentation of the bilateral spontaneous pneumocephalus associated with bilateral tegmen and dura mater defects managed surgically. Despite its rarity, spontaneous pneumocephalus originating from the temporal bone should be considered as a possible diagnosis in patients with suggestive otologic presentation (e.g., tinnitus, instability, hearing loss) and associated nonspecific neurologic symptomatology.