Thrombectomy in ischemic stroke patients with tandem occlusion in the posterior versus anterior circulation.

BACKGROUND: Mechanical thrombectomy (MT) was found to be beneficial in acute ischemic stroke patients with anterior tandem occlusion (a-TO). Instead, little is known about the effectiveness of MT in stroke patients with posterior tandem occlusion (p-TO). We aimed to compare MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO. METHODS: We conducted a cohort study on prospectively collected data of patients registered in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) who were treated with MT within 24 h from last known well time for acute ischemic stroke with p-TO (n = 275) or a-TO (n = 1853). RESULTS: After adjustment for unbalanced pre-procedure variables (year 2015-2021, age, sex, NIHSS score, ASPECTS, and time strata for puncture groin) and pre-stroke mRS score as pre-defined predictor, p-TO was significantly associated with lower probability of mRS score 0-2 (OR 0.415, 95% CI 0.268-0.644) and with higher risk of death (OR 2.813, 95% CI 2.080-3.805) at 3 months. After adjustment for unbalanced procedural and post-procedure variables (IVT, general anesthesia, TICI 3, and 24-h HT) and pre-stroke mRS score as pre-defined predictor, association between p-TO and lower probability of mRS score 0-2 (OR 0.444, 95% CI 0.304-0.649) and association between p-TO and with higher risk of death (OR 2.971, 95% CI 1.993-4.429) remained significant. CONCLUSIONS: MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO was associated with worse outcomes at 3 months.

Stroke with large vessel occlusion in the posterior circulation: IV thrombolysis plus thrombectomy versus IV thrombolysis alone.

Efficacy and safety of mechanical thrombectomy (MT) for stroke with posterior circulation large vessel occlusion (LVO) is still under debate. We aimed to compare the outcomes of stroke patients with posterior circulation LVO treated with intravenous thrombolysis (IVT) (< 4.5 h after symptom onset) plus MT < 6 h after symptom onset with those treated with IVT alone (< 4.5 h after symptom onset). Patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) and in the Italian centers included in the SITS-ISTR were analysed. We identified 409 IRETAS patients treated with IVT plus MT and 384 SITS-ISTR patients treated with IVT alone. IVT plus MT was significantly associated with higher rate of sICH (ECASS II) compared with IVT alone (3.1 vs 1.9%; OR 3.984, 95% CI 1.014-15.815), while the two treatments did not differ significantly in 3-month mRS score ≤ 3 (64.3 vs 74.1%; OR 0.829, 95% CI 0.524-1.311). In 389 patients with isolated basilar artery (BA) occlusion, IVT plus MT was significantly associated with higher rate of any ICH compared with IVT alone (9.4 vs 7.4%; OR 4.131, 95% CI 1.215-14.040), while two treatments did not differ significantly in 3-month mRS score ≤ 3 and sICH per ECASS II definition. IVT plus MT was significantly associated with higher rate mRS score ≤ 2 (69.1 vs 52.1%; OR 2.692, 95% CI 1.064-6.811) and lower rate of death (13.8 vs 27.1%; OR 0.299, 95% CI 0.095-0.942) in patients with distal-segment BA occlusion, while two treatments did not differ significantly in 3-month mRS score ≤ 3 and sICH per ECASS II definition. IVT plus MT was significantly associated with lower rate of mRS score ≤ 3 (37.1 vs 53.3%; OR 0.137, 0.009-0.987), mRS score ≤ 1 (22.9 vs 53.3%; OR 0.066, 95% CI 0.006-0.764), mRS score ≤ 2 (34.3 vs 53.3%; OR 0.102, 95% CI 0.011-0.935), and higher rate of death (51.4 vs 40%; OR 16.244, 1.395-89.209) in patients with proximal-segment BA occlusion. Compared with IVT alone, IVT plus MT was significantly associated with higher rate of sICH per ECASS II definition in patients with stroke and posterior circulation LVO, while two treatment groups did not differ significantly in 3-month mRS score ≤ 3. IVT plus MT was associated with lower rate of mRS score ≤ 3 compared with IVT alone in patients with proximal-segment BA occlusion, whereas no significant difference was found between the two treatments in primary endpoints in patients isolated BA occlusion and in the other subgroups based on site occlusion.

IV thrombolysis plus thrombectomy versus IV thrombolysis alone for minor stroke with anterior circulation large vessel occlusion from the IRETAS and Italian SITS-ISTR cohorts.

INTRODUCTION: The aim of this study was to compare the outcomes of patients treated with intravenous thrombolysis (IVT) <4.5 h after symptom onset plus mechanical thrombectomy (MT) <6 h with those treated with IVT alone <4.5 h for minor stroke (NIHSS ≤5) with large vessel occlusion (LVO) in the anterior circulation. PATIENTS AND METHODS: Patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) and in the Italian centers included in the SITS-ISTR were analyzed. RESULTS: Among the patients with complete data on 24-h ICH type, 236 received IVT plus MT and 382 received IVT alone. IVT plus MT was significantly associated with unfavorable shift on 24-h ICH types (from no ICH to PH-2) (OR, 2.130; 95% CI, 1.173-3.868; p=0.013) and higher rate of PH (OR, 4.363; 95% CI, 1.579-12.055; p=0.005), sICH per ECASS II definition (OR, 5.527; 95% CI, 1.378-22.167; p=0.016), and sICH per NINDS definition (OR, 3.805; 95% CI, 1.310-11.046; p=0.014). Among the patients with complete data on 3-month mRS score, 226 received IVT plus MT and 262 received IVT alone. No significant difference was reported between IVT plus MT and IVT alone on mRS score 0-1 (72.1% versus 69.1%), mRS score 0-2 (79.6% versus 79%), and death (6.2% versus 6.1%). CONCLUSIONS: Compared with IVT alone, IVT plus MT was associated with unfavorable shift on 24-h ICH types and higher rate of 24-h PH and sICH in patients with minor stroke and LVO in the anterior circulation. However, no difference was reported between the groups on 3-month functional outcome measures.

Endovascular treatment of acute ischemic stroke due to tandem lesions of the anterior cerebral circulation: a multicentric Italian observational study.

PURPOSE: Acute ischemic stroke (AIS) due to tandem lesions (TLs) of extracranial Internal Carotid Artery and Anterior Cerebral Circulation are challenging for endovascular treatment (EVT). This study aims to evaluate feasibility, safety and efficacy of EVT for TLs' AIS, with or without emergent carotid artery stenting (eCAS), in a real-life scenario. METHODS: Retrospective review of prospectively collected non-randomized thrombectomy databases from five stroke centers between 2015 and 2019. Consecutive patients with TLs' AIS were selected. Clinical, neuroimage and procedure features, as well as antiplatelet therapy regimen, were evaluated. Primary outcome was 90-day mRS ≤ 2. Secondary outcomes included: mTICI score 2b-3, extracranial recanalization, procedural complications, symptomatic intracerebral hemorrhage (SICH) and 90-day mortality. RESULTS: Two hundred twenty-seven patients were enrolled (67.8% males; mean age 65.9 ± 12.9 years). We obtained mTICI 2b-3 in 77.1%, extracranial recanalization in 86.8%, 90-day mRS (available in 201/227 cases) ≤ 2 in 49.8%. Procedural complications occurred in 16.7%, SICH in 9.7%; 90-day mortality rate (available in 201/227 cases) was 14.4%. The strongest predictors of good clinical outcome were young age (p < 0.0001), low baseline NIHSS (p = 0.008), high baseline ASPECTS (p < 0.0001), good collateral flow (p = 0.013) and extracranial recanalization (p = 0.001). The most significant predictors of SICH were low baseline ASPECTS (p < 0.0001), occurrence of complications (p < 0.0001) and eCAS (p = 0.002). CONCLUSION: In our real-life series, the EVT for TLs' AIS was feasible, safe and effective in improving 90-day functional outcome with acceptable morbi-mortality rates. ECAS increased the risk of SICH, independently from the antiplatelet therapy regimen.

Acute Stroke Management During the COVID-19 Pandemic: Does Confinement Impact Eligibility for Endovascular Therapy?

During the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organization recommended measures to mitigate the outbreak such as social distancing and confinement. Since these measures have been put in place, anecdotal reports describe a decrease in the number of endovascular therapy (EVT) treatments for acute ischemic stroke due to large vessel occlusion. The purpose of our study was to determine the effect on EVT for patients with acute ischemic stroke during the COVID-19 confinement. In this retrospective, observational study, data were collected from November 1, 2019, to April 15, 2020, at 17 stroke centers in countries where confinement measures have been in place since March 2020 for the COVID-19 pandemic (Switzerland, Italy, France, Spain, Portugal, Germany, Canada, and United States). This study included 1600 patients treated by EVT for acute ischemic stroke. Date of EVT and symptom onset-to-groin puncture time were collected. Mean number of EVTs performed per hospital per 2-week interval and mean stroke onset-to-groin puncture time were calculated before confinement measures and after confinement measures. Distributions (non-normal) between the 2 groups (before COVID-19 confinement versus after COVID-19 confinement) were compared using 2-sample Wilcoxon rank-sum test. The results show a significant decrease in mean number of EVTs performed per hospital per 2-week interval between before COVID-19 confinement (9.0 [95% CI, 7.8-10.1]) and after COVID-19 confinement (6.1 [95% CI, 4.5-7.7]), (P<0.001). In addition, there is a significant increase in mean stroke onset-to-groin puncture time (P<0.001), between before COVID-19 confinement (300.3 minutes [95% CI, 285.3-315.4]) and after COVID-19 confinement (354.5 minutes [95% CI, 316.2-392.7]). Our preliminary analysis indicates a 32% reduction in EVT procedures and an estimated 54-minute increase in symptom onset-to-groin puncture time after confinement measures for COVID-19 pandemic were put into place.

General Anesthesia Versus Conscious Sedation and Local Anesthesia During Thrombectomy for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: As numerous questions remain about the best anesthetic strategy during thrombectomy, we assessed functional and radiological outcomes in stroke patients treated with thrombectomy in presence of general anesthesia (GA) versus conscious sedation (CS) and local anesthesia (LA). METHODS: We conducted a cohort study on prospectively collected data from 4429 patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke. RESULTS: GA was used in 2013 patients, CS in 1285 patients, and LA in 1131 patients. The rates of 3-month modified Rankin Scale score of 0-1 were 32.7%, 33.7%, and 38.1% in the GA, CS, and LA groups: GA versus CS: odds ratios after adjustment for unbalanced variables (adjusted odds ratio [aOR]), 0.811 (95% CI, 0.602-1.091); and GA versus LA: aOR, 0.714 (95% CI, 0.515-0.990). The rates of modified Rankin Scale score of 0-2 were 42.5%, 46.6%, and 52.4% in the GA, CS, and LA groups: GA versus CS: aOR, 0.902 (95% CI, 0.689-1.180); and GA versus LA: aOR, 0.769 (95% CI, 0.566-0.998). The rates of 3-month death were 21.5%, 19.7%, and 14.8% in the GA, CS, and LA groups: GA versus CS: aOR, 0.872 (95% CI, 0.644-1.181); and GA versus LA: aOR, 1.235 (95% CI, 0.844-1.807). The rates of parenchymal hematoma were 9%, 12.6%, and 11.3% in the GA, CS, and LA groups: GA versus CS: aOR, 0.380 (95% CI, 0.262-0.551); and GA versus LA: aOR, 0.532 (95% CI, 0.337-0.838). After model of adjustment for predefined variables (age, sex, thrombolysis, National Institutes of Health Stroke Scale, onset-to-groin time, anterior large vessel occlusion, procedure time, prestroke modified Rankin Scale score of <1, antiplatelet, and anticoagulant), differences were found also between GA versus CS as regards modified Rankin Scale score of 0-2 (aOR, 0.659 [95% CI, 0.538-0.807]) and GA versus LA as regards death (aOR, 1.413 [95% CI, 1.095-1.823]). CONCLUSIONS: GA during thrombectomy was associated with worse 3-month functional outcomes, especially when compared with LA. The inclusion of an LA arm in future randomized clinical trials of anesthesia strategy is recommended.

Endovascular Thrombectomy for Acute Ischemic Stroke Beyond 6 Hours From Onset: A Real-World Experience.

BACKGROUND AND PURPOSE: To evaluate outcome and safety of endovascular treatment beyond 6 hours of onset of ischemic stroke due to large vessel occlusion in the anterior circulation, in routine clinical practice. METHODS: From the Italian Registry of Endovascular Thrombectomy, we extracted clinical and outcome data of patients treated for stroke of known onset beyond 6 hours. Additional inclusion criteria were prestroke modified Rankin Scale score ≤2 and ASPECTS score ≥6. Patients were selected on individual basis by a combination of CT perfusion mismatch (difference between total hypoperfusion and infarct core sizes) and CT collateral score. The primary outcome measure was the score on modified Rankin Scale at 90 days. Safety outcomes were 90-day mortality and the occurrence of symptomatic intracranial hemorrhage. Data were compared with those from patients treated within 6 hours. RESULTS: Out of 3057 patients, 327 were treated beyond 6 hours. Their mean age was 66.8±14.9 years, the median baseline National Institutes of Health Stroke Scale 16, and the median onset to groin puncture time 430 minutes. The most frequent site of occlusion was middle cerebral artery (45.1%). Functional independence (90-day modified Rankin Scale score, 0-2) was achieved by 41.3% of cases. Symptomatic intracranial hemorrhage occurred in 6.7% of patients, and 3-month case fatality rate was 17.1%. The probability of surviving with modified Rankin Scale score, 0-2 (odds ratio, 0.58 [95% CI, 0.43-0.77]) was significantly lower in patients treated beyond 6 hours as compared with patients treated earlier No differences were found regarding recanalization rates and safety outcomes between patients treated within and beyond 6 hours. There were no differences in outcome between people treated 6-12 hours from onset (278 patients) and those treated 12 to 24 hours from onset (49 patients). CONCLUSIONS: This real-world study suggests that in patients with large vessel occlusion selected on the basis of CT perfusion and collateral circulation assessment, endovascular treatment beyond 6 hours is feasible and safe with no increase in symptomatic intracranial hemorrhage.

Appropriateness, safety, and effectiveness of "drip and ship" teleconsultation model in Southeastern Tuscany: a feasibility study.

PURPOSE: Teleconsultation is a consultation between two or more physicians about the diagnostic work-up and therapeutic strategy in the treatment of an individual case by means of modern telematics. 'Drip-and-ship' teleconsultation model consists of the transfer of patients, through telematics stroke networks, with large arteries occlusions from primary to comprehensive stroke centers equipped for endovascular therapy. We retrospectively investigated appropriateness, safety, and effectiveness of 'drip-and-ship' teleconsultation model in a rural area of Tuscany. METHODS: Outcome measures were: door-to-ship time (including door-to-needle time), ratio of number treated/total sent patients, adverse events/mortality during transfer, and mortality and modified Rankin scale at 90 days. Analysis of non-treated patients was also done. RESULTS: Seventy-eight patients were included; 16/78 patients were sent for endovascular therapy alone, and 62/78 for "drip-and-ship"; 12 patients were not treated. Door-to-ship, and door-to-needle times (mean ± SD) were 105 ± 29.8 and 62.5 ± 37.5 min, respectively. The ratio number of treated/total sent patients was 0.85. At 90 days, the global mortality rate was 21%, and 40% of patients showed favorable outcome. The main cause of non-treatment was spontaneous recanalization. CONCLUSIONS: The high value for treated/total sent patients' ratio underlines that "drip-and-ship" teleconsultation model is appropriate and effective, with a few untreated patients. The model is safe, without adverse events during transfer. Taken together, our outcomes are in line with the previous reports. "Drip-and-ship" teleconsultation model is safe and effective in rural areas, allowing good selections and rapid treatments for stroke patients, based on the transfer from the primary to the comprehensive stroke center.

Efficacy of ADAPT with large-bore reperfusion catheter in anterior circulation acute ischemic stroke: a multicentric Italian experience.

INTRODUCTION: A direct aspiration first pass technique (ADAPT) is an alternative technique as first-line thrombectomy for large vessel occlusion in acute ischemic stroke, still debated when compared to first-line stent retriever. To retrospectively evaluate technical and clinical outcomes of the ADAPT as first-line treatment for anterior circulation acute ischemic stroke with large-bore reperfusion catheters. METHODS: A multicentric data collection from 14 medical centers was retrospectively analyzed. Large-bore catheters had a distal diameter between 0.64 and 0.71 in; stent retriever was added when aspiration alone failed. Baseline characteristics, technical and clinical variables were collected, including NIHSS, thrombolysis in cerebral infarction (TICI), peri-procedural complications, 90-day mRS and 90-day mortality. RESULTS: Overall, 501 patients were treated. No statistically significant difference in terms of baseline features or tPA administration was recorded between patients treated with ADAPT and with additional stent retriever. ADAPT alone was successful in achieving TICI ≥ 2b in 71.8% with a median of 1.55 aspiration attempts. In terms of TICI ≥ 2b, ADAPT alone was better than additional stent retriever (p < 0.001), while no statistical difference was achieved from catheter diameter. Embolization to a new territory was less frequent in ADAPT group (5.2 vs 18%; p = 0.0026). Patients treated with ADAPT alone had better clinical outcomes in terms of mRS ≤ 2 (p < 0.001). CONCLUSIONS: ADAPT is a valid technique with respect to the rates of TICI 2b/3 recanalization and 90-day mRS scores. In this series, an attempt at recanalization with ADAPT with larger-bore reperfusion catheter may be warranted prior to stentriever thrombectomy.

IER-SICH Nomogram to Predict Symptomatic Intracerebral Hemorrhage After Thrombectomy for Stroke.

Background and Purpose- As a reliable scoring system to detect the risk of symptomatic intracerebral hemorrhage after thrombectomy for ischemic stroke is not yet available, we developed a nomogram for predicting symptomatic intracerebral hemorrhage in patients with large vessel occlusion in the anterior circulation who received bridging of thrombectomy with intravenous thrombolysis (training set), and to validate the model by using a cohort of patients treated with direct thrombectomy (test set). Methods- We conducted a cohort study on prospectively collected data from 3714 patients enrolled in the IER (Italian Registry of Endovascular Stroke Treatment in Acute Stroke). Symptomatic intracerebral hemorrhage was defined as any type of intracerebral hemorrhage with increase of ≥4 National Institutes of Health Stroke Scale score points from baseline ≤24 hours or death. Based on multivariate logistic models, the nomogram was generated. We assessed the discriminative performance by using the area under the receiver operating characteristic curve. Results- National Institutes of Health Stroke Scale score, onset-to-end procedure time, age, unsuccessful recanalization, and Careggi collateral score composed the IER-SICH nomogram. After removing Careggi collateral score from the first model, a second model including Alberta Stroke Program Early CT Score was developed. The area under the receiver operating characteristic curve of the IER-SICH nomogram was 0.778 in the training set (n=492) and 0.709 in the test set (n=399). The area under the receiver operating characteristic curve of the second model was 0.733 in the training set (n=988) and 0.685 in the test set (n=779). Conclusions- The IER-SICH nomogram is the first model developed and validated for predicting symptomatic intracerebral hemorrhage after thrombectomy. It may provide indications on early identification of patients for more or less postprocedural intensive management.

Intra-arterial chemotherapy for retinoblastoma: the dosimetric impact.

PURPOSE: Purposes are (1) to measure main radiation parameters and (2) to propose a method to estimate the absorbed doses of internal organs starting from DAP values. Measuring the exposition of internal organs by repeated irradiations on an anthropomorphic phantom with the same settings used in vivo, we could establish correlations between (1) DAP and the dose recorded by a dosimeter placed along the X-ray beam entrance pathway; (2) the dose recorded by the same dosimeter and the absorbed dose in internal organs. METHODS: Forty-four consecutive patients (16 males, 28 females) (mean age 35.4 months) treated at our institution with IAC (216 procedures: 196 via the ICA and 20 into branches of the ECA) were included in this prospective study. IAC was divided into 5 phases. Fluoroscopic time, DAP, and ESD were measured. RESULTS: The mean DAP was 595 ± 445 cGy cm2 and the mean fluoroscopic time was 540 ± 403 s. ESD was on average 9.59 mGy (range 0.8-165 mGy). The absorbed dose was lower than 12.1 mGy in the left retina (the more exposed organ) in 75% of single treatments and lower than 25 mGy in 95% of treatments. In the cases of 3 and 6 sessions, the left retina of 75% of patients absorbed respectively less than 36.3 and 72.7 mGy, whereas the left retina of 95% of patients received less than 75.2 and 150.4 mGy. Other organs were less exposed. CONCLUSION: This paper describes a method of absorbed dose estimation providing ranges used clinically in a single practice and the basis for further prospective studies.

Single-center experience using the 3MAX or 4MAX reperfusion catheter for the treatment of acute ischemic stroke with distal arterial occlusions in patients not eligible for intravenous fibrinolysis.

BACKGROUND: In acute stroke, distal cerebrovascular occlusions can be linked to severe clinical symptoms, and treatment by mechanical thrombectomy may have an important clinical impact. When intravenous fibrinolytic therapy is firmly contraindicated, it remains the only treatment option. METHODS: A total of 42 patients with isolated distal arterial occlusions and absolute contraindication for intravenous fibrinolytic therapy were retrospectively included. Mechanical thrombectomy was performed using Penumbra 4MAX or 3MAX aspiration catheters. When aspiration alone did not result in successful revascularization, a stent retriever was added. RESULTS: Direct thromboaspiration was the first treatment option in all patients. 16.7% of cases required the additional use of a stent retriever. A TICI score ≥ 2b reperfusion at the end of the procedure was obtained in 76.2% and a Rankin Score of 2 or less at 90 days in 45.7%. Two hemorrhagic complications were observed. CONCLUSIONS: Direct thromboaspiration appears a safe technique in acute isolated distal arterial occlusions. In a cohort of patients with absolute contraindication for intravenous fibrinolytic therapy, a significant percentage achieved good revascularization.

An update on the variations of the orbital blood supply and hemodynamic.

PURPOSE: Several variations of the arterial blood supply of the orbit have been reported over the years. This review is aimed to provide an update focusing on three important issues: (a) variations of the ophthalmic artery origin; (b) contribution of the external carotid artery to the orbital blood supply; (c) orbital hemodynamic. METHODS: A PubMed and Google search was carried out with the following keywords: ophthalmic artery origin, ophthalmic artery anastomoses and ophthalmic artery anatomy. RESULTS: The site of origin of the ophthalmic artery displays a limited number of variations. However they are important as they are also associated with course variations. Anastomoses between the ophthalmic artery and the external carotid artery are numerous and many of them can acquire clinical relevance. Records on their anatomic frequency are limited. Orbital hemodynamic variations are a poorly studied subject. Recent investigations in children have unveiled unexpected variability and instability in the way the blood flows through the orbit. CONCLUSIONS: The orbit shows several possible arterial variations. Some of them have a profound influence on its hemodynamic at least in children. More studies are required to ascertain if the hemodynamic variability observed in children can be pinpointed also in adults.

Double ophthalmic arteries arising from the internal carotid artery: a case report of a hidden second ophthalmic artery.

A case of double ophthalmic arteries arising from the internal carotid artery with unique features is reported. This case was discovered following in the course of time the progress of a thrombosis of the anterior cavernous sinus associated with a low-flow direct arteriovenous fistula of the superior ophthalmic vein. At different time points, the same patient underwent four angiographic studies and one computerized tomography with contrast medium. Angiographies showed that the double internal carotid artery origin of the ophthalmic artery was detectable only within a short range of time. To the best of our knowledge, this case is unique as it demonstrates that a second ophthalmic artery may lie hidden, showing itself only under particular hemodynamic requirements.

Clinical anatomy of the orbitomeningeal foramina: variational anatomy of the canals connecting the orbit with the cranial cavity.

PURPOSE: In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice. METHODS: Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen. RESULTS: Orbitomeningeal foramina were detected in 59.46% of skulls and in 54% of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17% of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina. CONCLUSIONS: Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.

Transorbital anastomotic pathways between the external and internal carotid systems in children affected by intraocular retinoblastoma.

PURPOSE: It is well known that many anastomoses can join the external carotid system and the ophthalmic artery. However, their frequency has never been reported. Since they can be relevant for interventional radiologists operating in the orbit, we decided to illustrate and determine the frequency of the anastomoses that can be found in children. METHODS: A retrospective study of 443 angiographic procedures (via ophthalmic artery and/or external carotid artery) carried out on 97 children affected by intraocular retinoblastoma was made to investigate the arterial anatomy of 106 orbits. RESULTS: Anastomoses were observed in 44.33 % of orbits. However, their true frequency is likely much higher as the rate of visualization increased up to 91.11 % of orbits when the angiographic study was extended to the external carotid artery. In order of frequency we detected the following anastomoses: lacrimal artery-middle meningeal artery, lacrimal artery-anterior deep temporal artery, ophthalmic artery-middle meningeal artery, ophthalmic artery-facial artery, supraorbital artery-superficial temporal artery, supratrochlear artery-superficial temporal artery, supraorbital artery-middle meningeal artery, dorsal nasal artery-infraorbital artery, supraorbital artery-zygomaticoorbital artery, lacrimal artery-zygomaticoorbital artery. CONCLUSION: When properly searched, anastomoses between the ophthalmic artery and the external carotid artery are almost constant in children. Depending on the clinical scenario, they can represent dangers or valuable alternative routes for collateral circulations and intraarterial chemotherapy.

Identification of Intraorbital Arteries in Pediatric Age by High Resolution Superselective Angiography.

PURPOSE: Angiography is a powerful tool to identify intraorbital arteries. However, the incidence by which these vessels can be identified is unknown. Our purpose was to determine such incidence and which angiographic approach is best for the identification of each artery. METHODS: A retrospective study of 353 angiographic procedures (via ophthalmic artery and/or external carotid artery) carried out on 79 children affected by intraocular retinoblastoma was made to investigate the arterial anatomy in 87 orbits. For each intraorbital artery two parameters were calculated: the angiographic incidence, as the percentage of times a given artery was identified, and the visibility index, as the ratio between the angiographic incidence and the true anatomic incidence. RESULTS: All collaterals of the ophthalmic artery could be spotted. Most of them were identified with a high angiographic incidence; some of them were less easily identified because too thin or because frequently shielded. The visibility index paralleled the angiographic incidence of most arteries. However, the lacrimal and meningolacrimal arteries had a higher visibility index suggesting that their identification was more frequent than the angiographic incidence alone could suggest. Statistical analysis demonstrated that the lacrimal artery and some muscular branches had higher chances to be identified if the angiography of the ophthalmic artery was accompanied by the study of the external carotid system. CONCLUSION: This work provides an objective measure of how powerful angiography is to identify intraorbital arteries as well as useful references for professionals who need to operate in the orbit.