A complication of recurrent artery of Heubner infarction after resection of a giant thrombotic aneurysm in the anterior cerebral artery A2 segment: case report

Giant thrombotic aneurysms of the anterior cerebral artery (ACA) are rare and pose significant challenges due to their variable clinical presentations. While complications following surgical interventions for these aneurysms are known, they have not been fully characterized. We present a novel case of postoperative infarction in the recurrent artery of Heubner (RAH) following resection of a thrombotic giant aneurysm in the ACA. A 53-year-old man with no prior systemic illnesses presented with progressive weakness in his left hand and foot, along with slurred speech. Imaging studies revealed a giant thrombotic aneurysm in the proximal A2 segment of the right ACA, which was completely occluded. Additionally, a chronic infarction was identified in the territory of the right ACA. The patient underwent successful surgical resection of the aneurysm. However, he subsequently developed an infarction in the RAH territory, a complication rarely reported in the literature. This case highlights the importance of comprehensive preoperative evaluation and underscores the need to anticipate and manage potential complications following surgery.

Giant Aneurysm Management

The treatment of giant aneurysms has always been a challenge in the field of neurovascular disease. Giant aneurysms are larger in size and are associated with thrombosis development and the calcification of the aneurysmal wall and neck, which often interfere with direct clipping. Most giant aneurysms have a wide neck with an incomplete thrombus, making complete embolization almost impossible. Giant aneurysms of different sites have entirely different hemodynamic characteristics. Moreover, aneurysms at the same site may exhibit very different hemodynamics among different individuals. Therefore, careful assessment of each case is required before and during treatment to develop and carry out an individualized treatment plan.

A Deep Learning Model with High Standalone Performance for Diagnosis of Unruptured Intracranial Aneurysm

PURPOSE

This study aimed to investigate whether a deep learning model for automated detection of unruptured intracranial aneurysms on time-of-flight (TOF) magnetic resonance angiography (MRA) can achieve a target diagnostic performance comparable to that of human radiologists for approval from the Korean Ministry of Food and Drug Safety as an artificial intelligence-applied software.

MATERIALS AND METHODS

In this single-center, retrospective, confirmatory clinical trial, the diagnostic performance of the model was evaluated in a predetermined test set. After sample size estimation, the test set consisted of 135 aneurysm-containing examinations with 168 intracranial aneurysms and 197 aneurysm-free examinations. The target sensitivity and specificity were set as 87% and 92%, respectively. The patient-wise sensitivity and specificity of the model were analyzed. Moreover, the lesion-wise sensitivity and false-positive detection rate per case were also investigated.

RESULTS

The sensitivity and specificity of the model were 91.11% [95% confidence interval (CI): 84.99, 95.32] and 93.91% (95% CI: 89.60, 96.81), respectively, which met the target performance values. The lesion-wise sensitivity was 92.26%. The overall false-positive detection rate per case was 0.123. Of the 168 aneurysms, 13 aneurysms from 12 examinations were missed by the model.

CONCLUSION

The present deep learning model for automated detection of unruptured intracranial aneurysms on TOF MRA achieved the target diagnostic performance comparable to that of human radiologists. With high standalone performance, this model may be useful for accurate and efficient diagnosis of intracranial aneurysm.

Introducing the Rupture Criticality Index to Compare Risk Factor Combinations Associated With Aneurysmal Rupture

BACKGROUND

Relative risk is insufficient to guide treatment decision-making for unruptured intracranial aneurysms. Our objective was to introduce a novel risk assessment methodology called the Rupture Criticality Index (RCI), which allows for concurrent evaluation of groups of risk factors (RFs).

METHODS

From a retrospective database of saccular aneurysms, we identify 915 patients and delineate 50 potential RFs for aneurysms in 11 unique locations. RF combinations for multivariable analysis were defined by aneurysm size, location, and a third variable from the study design. Data analysis was performed by applying frequency distribution methods to define the RCI of each RF combination.

RESULTS

RF combinations at greatest risk were small (4.8-8.2 mm) or medium (8.3-14.5 mm) anterior communicating aneurysms (ACoA) in male individuals (RCI 9.87-10), small ACoA in those ≤37 years or 38-55 years (RCI 8.67-8.99), medium basilar tip aneurysms (BTAs) in male individuals (RCI 10), and large (14.6-22.5 mm) BTA in Caucasians or those aged 38-55 years (RCI 9.25, 9.35, respectively).

CONCLUSIONS

We introduce the concept of RCI and compare how RF combinations are associated with aneurysmal rupture. This novel approach to aneurysmal rupture identifies high-risk clinical presentations and can be used to guide clinical decision-making in patients with non-traditional risks.

Surgical Management of Giant Intracranial Aneurysms: Overall Results of a Large Series

OBJECTIVE

To review and discuss surgical treatment options for giant intracranial aneurysms (GIAs), focusing on indications, technical aspects, and results, along with some illustrative cases.

METHODS

We reviewed the data of 82 consecutive patients surgically managed between January 2000 and December 2019 for treatment of a GIA.

RESULTS

Male sex and hemorrhage at presentation were prevalent. The average follow-up was 81.2 ± 45 months. The anterior circulation was involved in 76.8% of GIAs. If the GIA showed a clear neck, minimal atherosclerosis, or intrasaccular thrombosis, and ≤2 branches arising from the neck, it was reconstructed. This procedure was possible in 78% of cases. The technique also involved temporary clipping, remodeling, and thrombectomy, as well as fragmentation techniques. Angioarchitectural features other than these techniques underwent bypass and aneurysm trapping. Most bypasses were extracranial to intracranial and high flow. Flow capacity, collateral circulation, and availability of the donor vessel mainly affected the choice of the type of bypass. Overall, successful exclusion of the GIA was 91.4%. The need for retreatment and complication rate were 3.6% and 19.5%, respectively. A good overall outcome (modified Rankin Scale score 0-3) was achieved in 84.2% of patients, and mortality was 10%.

CONCLUSIONS

Microneurosurgical techniques still maintain a significant role for most GIAs, with a high durability and acceptable rate of morbidity and mortality. Clip reconstruction is the first-line surgical treatment option, whereas bypass is indicated in cases of planned or unplanned sacrifice of the parent artery to prevent long-term ischemic complications.

Multimodal management of giant cerebral aneurysms: review of literature and case presentation

The pathophysiology of giant cerebral aneurysms renders them difficult to treat. Advances in technology have attempted to address any shortcomings associated with open surgery or endovascular therapies. Since the introduction of the flow diversion technique, the endovascular approach with flow diversion has become the first-line modality chosen to treat giant aneurysms. A subset of these giant aneurysms may persistent despite any treatment modality. Perhaps the best option for these recurrent and/or persistent giant aneurysms is to employ a multimodal approach-both surgical and endovascular-rather than any single technique to provide a curative result with favourable patient outcomes. This paper provides a review of the histopathology and treatment options for giant cerebral aneurysms. Additionally, an illustrative case is presented to highlight the unique challenges of a curative solution for giant cerebral aneurysms that persist despite initial treatment.

Decompressive Craniectomy: the Right Call at the Right Moment

Introduction:Massive intracerebral hemorrhages and large internal carotid artery infarcts may cause early death due to severe cerebral edema with elevated intracranial pressure, despite maximal medical therapy. Decompressive craniectomy may be of benefit to these patients in terms of survival and even functional outcome. The aim of our paper is to present two cases that illustrate the use of decompressive craniectomy both in ischemic and hemorrhagic stroke, followed by a discussion on the indication and right timing of the intervention, but also on the outcome of these patients. Materials and methods: We present the cases of a 38-year-old man with a right lenticular and capsular hemorrhage who underwent decompressive craniectomy in the first 24 hours from onset of symptoms and a 64-year-old patient with an ischemic stroke in the territory of the left carotid artery with a decompressive craniectomy performed at more than 72 hours from the beginning. For each of the two cases, we analyzed the following parameters: neurologic status, Glasgow Coma Scale, aspect of the cerebral computed tomography before and after surgery, in-hospital complications and modified Rankin Scale at discharge. Outcomes: While the intervention was life-saving in both cases, the procedure had different functional outcomes. Conclusion: Decompressive craniectomy may be a life-saving procedure for patients with both hemorrhagic or ischemic strokes complicated with massive edema and increased intracranial pressure. When performed in the first 48 hours, especially in patients with ischemic stroke aged less than 60, it may also improve the functional outcome compared to conservative treatment.

Unruptured Giant Intracerebral Aneurysms: Serious Trouble Requiring Serious Treatment - Case Report and Literature Review

Giant intracranial aneurysms (ICGA) represent 3 to 5% of all intracranial aneurysms in adults. They are defined as arterial dilatations, with more than 25 mm in diameter. Despite important advances in the research of endovascular techniques of treating giant intracranial aneurysms, the management of these vascular malformations still poses great difficulties for neurologists and interventional radiologists. In particular, these challenges arise from the difficult and modified cerebral anatomy of patients with ICGA. Choosing the best treatment for patients with ICGA involves not only finding the perfect balance between the potential risks and benefits of endovascular treatment, but also taking into consideration the patient's biological condition and associated diseases. The aim of this paper is to describe the decisional algorithm of treating patients with giant intracranial aneurysms and factors which could influence the choice of endovascular technique. We report a clinical case of a 63-year-old female with cardio-vascular risk factors (atrial fibrillation, high blood pressure), diagnosed with a symptomatic giant aneurysm of the right internal carotid artery and multiple cerebral micro-bleeds. Given the very large size of the aneurysm, its characteristics as well as patient's associated comorbidities, it was decided to exclude the ICA aneurysm from circulation by occluding the parent vessel (right internal carotid artery) by using endovascular techniques. Also, a review of the literature on the currently available endovascular methods for treating patients with giant intracranial aneurysms was performed in order to see the indications and possible long-term complications of each method. In selected cases, the risks of serious complications associated with occluding a large cervical-cerebral vessel (as the internal carotid artery) are far exceeded by the risk for rupture of giant aneurysms, which is fatal in many cases. Nevertheless, it is of utmost importance to mention that, although the use of endovascular methods leads to a significant increase in life expectancy, a severe decline in quality of life might be experienced by these patients.

Tulip Giant Aneurysm Amputation and "Shingle Clip Cut Clip" Technique for Microsurgical Reconstruction of a Giant Thrombosed Middle Cerebral Artery Aneurysm

In this video, we present the case of a 61-year-old female who was brought to the emergency department after she had partial complex seizures. Computed tomography and magnetic resonance imaging of the brain revealed a right temporal lobe mass, which was initially thought to be a tumor. The patient was therefore referred to us for further management. The round nature of the lesion raised suspicion for an aneurysm. Computed tomography angiography was performed, followed by a diagnostic conventional cerebral angiogram, and confirmed the presence of a giant thrombosed aneurysm. Giant aneurysms represent 3%-5% of all cerebral aneurysms.¹ They are more common in females with a ratio of 2:1 to 3:1.¹ They have a high risk of rupture up to 50% in the posterior circulation and 40% in the anterior circulation over 5 years according to the International Study of Unruptured Intracranial Aneurysms Investigators.^2,3 Their treatment can be complex and treacherous. Treatment options vary widely from parent artery sacrifice in select cases to clip reconstruction to an array of endovascular approaches such as flow diversion. In some cases a combination of both open and endovascular approaches might be necessary.^4-8 In our case, we opted for an open surgical clip reconstruction. A superior temporal artery-middle cerebral artery bypass was attempted to allow for trapping of the aneurysm without risking ischemic complication distal to it. Unfortunately, the patient's vessels were too atherosclerotic to maintain patency. A strategy was then devised, which consisted of cutting the dome of the aneurysm and clearing the distal two thirds of the clot ("tulip technique") and then completing thrombus resection under temporary occlusion. Once clot removal was completed, the aneurysm was clipped using the "shingle clip cut clip" technique (Video 1). The patient's postoperative course was uneventful, and the patient remained seizure free.

Machine Learning Application for Rupture Risk Assessment in Small-Sized Intracranial Aneurysm

The assessment of rupture probability is crucial to identifying at risk intracranial aneurysms (IA) in patients harboring multiple aneurysms. We aimed to develop a computer-assisted detection system for small-sized aneurysm ruptures using a convolutional neural network (CNN) based on images of three-dimensional digital subtraction angiography. A retrospective data set, including 368 patients, was used as a training cohort for the CNN using the TensorFlow platform. Aneurysm images in six directions were obtained from each patient and the region-of-interest in each image was extracted. The resulting CNN was prospectively tested in 272 patients and the sensitivity, specificity, overall accuracy, and receiver operating characteristics (ROC) were compared to a human evaluator. Our system showed a sensitivity of 78.76% (95% CI: 72.30%-84.30%), a specificity of 72.15% (95% CI: 60.93%-81.65%), and an overall diagnostic accuracy of 76.84% (95% CI: 71.36%-81.72%) in aneurysm rupture predictions. The area under the ROC (AUROC) in the CNN was 0.755 (95% CI: 0.699%-0.805%), better than that obtained from a human evaluator (AUROC: 0.537; p < 0.001). The CNN-based prediction system was feasible to assess rupture risk in small-sized aneurysms with diagnostic accuracy superior to human evaluators. Additional studies based on a large data set are necessary to enhance diagnostic accuracy and to facilitate clinical application.

Giant and Very Large Intracranial Aneurysms: Surgical Strategies and Special Issues

Giant intracranial aneurysms (GIAs) and very large intracranial aneurysms (VLAs) have a poor natural history because of a high incidence of bleeding and strokes. These lesions always represent a great challenge for neurosurgeons and interventional neuroradiologists because of some peculiar intrinsic features such as size, angioarchitecture, wide neck, mass effect, intraluminal thrombosis, atherosclerotic changes, involvement of branches and perforators, and a frequent need to perform revascularization procedures. The results of a cumulative surgical series of 75 VLAs and GIAs are reported. Thirty-three aneurysms were unruptured. Sixty aneurysms underwent direct surgical treatment consisting of 56 direct clippings, 3 trappings w/o revascularization, and 1 wrapping. Fifteen aneurysms were treated by means of extracranial to intracranial (EC-IC) high-flow bypass. An mRS score ranging between 0 and 2 was observed in 54 patients, whereas an mRS of 3 was seen in 5 patients. Four patients had a severe disability (mRS 4-5) and six patients died. Aneurysm's fragmentation, with stacking and seating clips, thrombectomy, and aneurysmorrhaphy were the techniques most frequently employed. Revascularization options involving EC-IC high-flow bypass were used in cases not amenable for direct treatment. Some technical tips and special issues related to the surgical management of these complex lesions are discussed.

Multimodality treatment of complex unruptured cavernous and paraclinoid aneurysms

BACKGROUND

Unruptured aneurysms of the cavernous and paraclinoid internal carotid artery can be approached via microsurgical and endovascular approaches. Trends in treatment reflect a steady shift toward endovascular techniques.

OBJECTIVE

To analyze our results with multimodal treatment.

METHODS

We reviewed patients with unruptured cavernous and paraclinoid internal carotid artery aneurysms proximal to the posterior communicating artery treated at a single center from 2007 to 2012. Treatment included 4 groups: (1) stent-assisted coiling, (2) pipeline endovascular device (PED) flow diverter, (3) clipping, and (4) trapping/bypass. Follow-up was 2 to 60 months.

RESULTS

The 109 aneurysms in 102 patients were studied with the following treatment groupings: 41 were done with stent-assisted coiling, 24 with Pipeline endovascular device, 24 by microsurgical clipping, and 20 by trap/bypass. Group: (1) two percent had delayed significant intraparenchymal hemorrhage; (2) thirteen percent had central nerve palsies, 8% had small asymptomatic infarcts, and 4% had small, asymptomatic remote-site hemorrhages; (3) twenty-nine percent of patients suffered from transient central nerve palsies, 4% experienced major stroke, and 8% had small intracerebral hemorrhages; (4) thirty-five percent had transient central nerve palsies, 10% had strokes, and 10% had intracerebral hemorrhages. In terms of follow-up obliteration, 83% had complete/nearly complete obliteration at last follow-up, 17% had residual aneurysms, and 10% required retreatment. Ninety-six percent of group 1 (35/38), 100% of group 2 (23/23), 100% of group 3 (21/21), and 95% of group 4 had modified Rankin Scale scores of 0 to 1.

CONCLUSION

Treatment of these aneurysms can be carried out with acceptable rates of morbidity. Careful patient selection is crucial for optimal outcome. Endovascular treatment volumes likely will continue to predominate over microsurgical techniques as changing skill sets evolve in neurosurgery, but individualized application of all available treatment options will continue.