Rupture Of Saccular Aneurysm Research Articles

Peculiarities of angiospasm and ischemic complications in ruptures of cerebral arterial aneurysms against the background of occlusive-stenotic lesions of cerebral arteries

Objective – to determine the effect of occlusive-stenotic lesions of cerebral arteries on angiospasm and ischemic complications in patients with ruptured arterial aneurysms against the background of occlusive-stenotic lesions of cerebral arteries. Materials and methods. A retrospective study of the medical histories of 1,147 patients with cerebral artery aneurysms from 2006 to 2022 was conducted. 63 patients were included in the study group because they met the following criteria: surgical treatment; rupture of saccular aneurysms (SAs); the presence of occlusive-stenotic lesions was proven using instrumental examination methods. Patients of the control group had to meet the following criteria: surgical treatment; rupture of SAs; the absence of occlusive-stenotic lesions was proven by means of instrumental examination methods; the gender and age distribution had to match the study group. Of the 126 patients included in this study, there were 76 men (60.32%) and 50 women (39.68%). The age of the patients varied from 31 to 77 years. The average age of patients- 55.9±0.76 years; men – 54.3±0.94 years, women – 58.3±1.19 years. Results. A percentage predominance of patients with high cerebral blood flow velocity (>200 cm/s, which is equal to the velocity with severe grade III vasospasm of the cerebral arteries) in the study group (32.56%) compared with the control group (24.24%) was revealed. Conclusions. The predominance of men among patients of the study group (60.32%) was established. The average age of men with occlusive-stenotic lesions was younger than that of women (men – 54.3±0.94 years, women – 58.3±1.19 years). The difference in age is the largest in the 2nd subgroup of the study group where the severity of stenosis is 50-75% (men - 48.3 years; women - 62 years). Ruptures of arterial aneurysms of the middle cerebral artery occur more often in the presence of stenoses (study group - 25.4%, control group - 12.7%). The neurological status of patients with a hemorrhagic stroke, as a result of the rupture of an arterial aneurysm, is significantly aggravated by occlusive-stenotic lesions due to the occurrence of chronic brain ischemia. The worst prognosis for life and health was in men with a ruptured arterial aneurysm against the background of a 50-75% stenotic lesion and severe vasospasm of the cerebral arteries.

The influence of sac centreline on saccular aneurysm rupture: computational study

The geometric characteristics of a saccular aneurysm play a crucial role in its rupturing. This article thoroughly investigates the impact of the sac centerline on aneurysm rupture, with a focus on identifying significant factors related to rupture at different time intervals. The study employs comprehensive computational simulations of six models of the ICA with varying coiling porosities and blood HCTs, using CFD analysis to examine WSS, OSI, pressure, and velocity within the saccular aneurysm for different sac centerlines. The results indicate that higher blood HCT levels lead to increased WSS and pressure values on the aneurysm wall, while OSI and mean velocity decrease. The study also reveals that coiling techniques can significantly reduce the risk of rupture, as decreasing coil porosity (increasing coil permeability) increases OSI and pressure while decreasing WSS and blood velocity within the aneurysm sac.

Rare Anatomic Variation of Anterior Communicating Artery Associated with a Rupture of Saccular Aneurysm

Although most cerebral aneurysms are considered as acquired degenerative lesions, diverse anatomical variations in the circle of Willis have been encountered, some of which may play an important role in lesion hemodynamics and pathogenesis. The coalescence of the small vascular plexus to form the anterior communicating artery at the 6-7-week embryological stage may lead to developmental variations, such as fenestration and duplication. Herein, we report a rare anatomical variant of the anterior communicating artery that was concomitantly identified with a ruptured aneurysm. Both the right and left anterior cerebral arteries were connected by three anterior communicating arteries. A vertical segmental artery was present and connected the two anterior communicating arteries, forming an H-shape or plexiform structure. Furthermore, a 0.6×0.4 cm-sized saccular aneurysm with antero-inferior projection was present in the middle anterior communicating artery. The combination of triplication and H-shape in the present case was compared to previously reported anatomical variants.

Prevention of complication in cerebral aneurysm microsurgery, associated with their non-radical clipping

Objective ‒ to analyze the effectiveness of intraoperative contact Doppler, repositioning the clip on the aneurysm and pilot clipping of the cervical aneurysm as the main methods of prevention of inadequate clipping of the cervical aneurysm in patients with intraoperative rupture of aneurysms. Materials and methods. Due to the use of intraoperative contact ultrasound Doppler control it was possible to avoid inadequate clipping of cerebral aneurysms in 16 cases, of which in 12 (75.00 %) cases ‒ incomplete clipping of cerebral aneurysms, in 3 (18.75 %) cases ‒ compression of the aneurysm’s artery-carrier, in 1 (6.25 %) case ‒ slipping of the clip with cerebral aneurysm. Perioperative examination of patients, in addition to intraoperative contact ultrasound Doppler control of radical clipping cerebral aneurysms, included clinical and neurological examination, computed tomography of the brain, cerebral angiography, ultrasound duplex scanning of the main vessels of the head and neck. In the analysis of observations of inadequate clipping of cerebral aneurysms (according to contact intraoperative Doppler), the following parameters were considered: size, location of cerebral aneurysm, timing of surgery after subarachnoid hemorrhage, anatomical forms of intracranial hemorrhage. Results. The purpose of the operations was to devascularize saccular aneurysm to prevent its re-rupture, to reduce the mass effect caused by intracerebral hematoma; reduction of intracranial pressure, rehabilitation of basal cisterns of the brain., But in the postoperative period there was a tendency to worsen the results of treatment, the appearance of focal neurological symptoms on the background of cerebral vasospasm with subsequent development of ischemic complications in patients with III‒V degree according to the Hunt‒Hess Scale on admission, in patients with prolonged temporary clipping of the cerebral aneurysm-artery and prolonged mechanical manipulation of the cerebral arteries and cerebral aneurysm. It should be noted that all patients in our sample, with complicated clipping of cerebral saccular aneurysms, had an intraoperative rupture of the MA, which complicated the process of clipping the saccular aneurysm and prolonged the time of surgery and was one of the inducers of postoperative aggravating consequences. There was a tendency to worsen the results of treatment in patients with III–IV degree according to the Hunt‒Hess Scale. Thus, patients with 1 point according to the Glasgow Outcome Scale, there were 2 patients who had II and III degrees according to Hunt–Hess Scale at hospitalization; among discharged patients with 3 point according to Glasgow Outcome Scale was dominated by patients from the second century according to Hunt‒Hess Scale at hospitalization, among patients with 5 point according to Glasgow Outcome Scale dominated patients who had I degree according to the Hunt‒Hess Scale at hospitalization. Conclusions. Inadequate clipping of the cervix cerebral aneurysm is the main type of non-hemorrhagic complications in the surgery of cerebral aneurysms. The Inadequate clipping of the cervix of the cerebral aneurysm includes the presence of residual blood flow in the cerebral aneurysm after its clipping, stenosis/compression of the main and perforating cerebral arteries with a clip, slipping of the clip from the aneurysm. Among the factors influencing the radical and adequate clipping of the cervix cerebral aneurysm are the size, location of the aneurysm, atherosclerotic lesions of the walls of the arteries and neck of the aneurysm and transferred subarachnoid hemorrhage. Reliable methods of prevention of inadequate clipping of saccular aneurysm are the use of intraoperative Doppler blood flow control, pilot clipping of complex aneurysms, optimization and individualization of surgical access. Aggravating factors that lead to unsatisfactory results of treatment of patients and negative clinical dynamics after the operation of clipping cerebral saccular aneurysm are: severe condition of the patient before surgery (III‒V gr. according to the Hunt‒Hess Scale), severe cerebral edema, intraoperative rupture of saccular aneurysm, long-term mechanical manipulations on cerebral arteries (long-term temporary clipping of saccular aneurysm, isolation of saccular aneurysm and «neighboring» cerebral arteries from arachnoid adhesions, frequent repositioning of the clip).

Spontaneous Renal Artery Aneurysm Rupture And Its Endovascular Treatment

Renal artery aneurysm is the local expansion of renal artery, its branches or both due to the weakening of the elastic tissue and media of arterial wall structure. It has four basic types as saccular, fusiform, dissected and intrarenal based on Poutasse classification, there is a gradual increase in proofs and study results showing that endovascular treatment should be preferred in renal artery aneurysm treatment in correlation with the endovascular experience and technology improving especially in recent years. Our aim in this case presentation was to present the left renal artery saccular aneurysm rupture patient treated endovascularly and discuss with literature.

Finite element model of size, shape and blood pressure on rupture of intracranial saccular aneurysms

Rupture of intracranial saccular aneurysms is a primary concern for neurologists and patients because it leads to stroke and permanent disability. This paper examines the role of blood pressure, in connection with size of and wall thickness, in the rupture of saccular aneurysms. A bulb-shaped geometry of a saccular aneurysm is obtained from angiographic images of a patient and modeled using Finite Elements based on the principle of virtual work under the Fung stress-strain relationship. The numerical model is subjected to varying levels of systolic blood pressure. Rupture is assumed to occur when the wall stress exceeded its mechanical strength. The results show which sizes of this class of aneurysms are at high risk of rupture for varying levels of blood pressure.

Pathological findings of saccular cerebral aneurysms-impact of subintimal fibrin deposition on aneurysm rupture.

Although several studies have suggested that aneurysmal wall inflammation and laminar thrombus are associated with the rupture of saccular aneurysms, the mechanisms leading to the rupture remain obscure. We performed full exposure of aneurysms before clip application and attempted to keep the fibrin cap on the rupture point. Using these specimens in a nearly original state before surgery, we conducted a pathological analysis and studied the differences between ruptured and unruptured aneurysms to clarify the mechanism of aneurysmal wall degeneration. This study included ruptured (n = 28) and unruptured (n = 12) saccular aneurysms resected after clipping. All of the ruptured aneurysms were obtained within 24 h of onset. Immunostainings for markers of inflammatory cells (CD68) and classical histological staining techniques were performed. Clinical variables and pathological findings from ruptured and unruptured aneurysms were compared. Patients with ruptured or unruptured aneurysms did not differ by age, gender, size, location, and risk factors, such as hypertension, smoking, and hyperlipidemia. The absence or fragmentation of the internal elastica lamina, the myointimal hyperplasia, and the thinning of the aneurysmal wall were generally observed in both aneurysms. The existence of subintimal fibrin deposition, organized laminar thrombus, intramural hemorrhage, neovascularization, and monocyte infiltration are more frequently observed in ruptured aneurysms. Multivariate logistic regression analysis showed that ruptured aneurysm was associated with presence of subintimal fibrin deposition and monocyte infiltration. These findings suggest that subintimal fibrin deposition and chronic inflammation have a strong impact on degeneration of the aneurysmal wall leading to their rupture, and this finding may be caused by endothelial dysfunction.

The Helsinki rat microsurgical sidewall aneurysm model.

Experimental saccular aneurysm models are necessary for testing novel surgical and endovascular treatment options and devices before they are introduced into clinical practice. Furthermore, experimental models are needed to elucidate the complex aneurysm biology leading to rupture of saccular aneurysms. Several different kinds of experimental models for saccular aneurysms have been established in different species. Many of them, however, require special skills, expensive equipment, or special environments, which limits their widespread use. A simple, robust, and inexpensive experimental model is needed as a standardized tool that can be used in a standardized manner in various institutions. The microsurgical rat abdominal aortic sidewall aneurysm model combines the possibility to study both novel endovascular treatment strategies and the molecular basis of aneurysm biology in a standardized and inexpensive manner. Standardized grafts by means of shape, size, and geometry are harvested from a donor rat's descending thoracic aorta and then transplanted to a syngenic recipient rat. The aneurysms are sutured end-to-side with continuous or interrupted 9-0 nylon sutures to the infrarenal abdominal aorta. We present step-by-step procedural instructions, information on necessary equipment, and discuss important anatomical and surgical details for successful microsurgical creation of an abdominal aortic sidewall aneurysm in the rat.

Primary aortoesophageal fistula: A rare but fatal cause of upper gastrointestinal bleeding

A68-year-old woman was admitted to our EmergencyDepartment for hematemesis several times within oneday. She had a history of poorly controlled hyperten-sion and suffered from left intracranial saccular aneu-rysm rupture twice with sequelae of right hemiplegia.The patient denied chest pain. On physical examina-tion, her heart rate was 120 beats/min with bloodpressure of 121/76 mmHg. Other physical examina-tions were unremarkable. Laboratory data showedhemoglobin [Hb] 100 g/L (normal range 120–160 g/L) without coagulopathy (platelet 315 × 10

Vascular endothelial growth factor gene polymorphisms and intracranial aneurysms

The exact pathophysiology of the development and rupture of saccular aneurysms is still controversial. Several lines of evidence indicate a role for inflammatory processes. Similarly, abnormal angiogenesis might be related to aneurysm growth. Expression of angiogenesis factors is higher in patients harboring aneurysms. The aim of this study was to verify the association of two functionally active polymorphisms (+ 396 C>T and 18 bp microdeletion) in the vascular endothelial growth factor (VEGF) gene with both susceptibility to and clinical features of aneurysmal subarachnoid hemorrhage (SAH) in an Italian population. Allelic and genotypic frequencies of the + 396 C>T and the 18 bp microdeletion of the VEGF gene were determined in 200 patients and 200 healthy controls. Both allelic and genotypic frequencies of the examined polymorphisms in the VEGF gene were not significantly different between cases and controls. Furthermore, the different VEGF genotypes did not seem to significantly modify the main clinical features of the disease. Our data suggest that the VEGF gene is not a major genetic risk factor for aneurysmal subarachnoid hemorrhage.

Intraarterial schwannoma in horizontal segment of middle cerebral artery causing subarachnoid hemorrhage

A spontaneous subarachnoid hemorrhage (SAH) from the middle cerebral artery is most commonly caused by the rupture of saccular aneurysms and rarely by fusiform aneurysms or arterial dissections/dissecting aneurysms. To the authors' knowledge, this is the first report of an intraarterial neoplasm causing an SAH. A 44-year-old woman presented with an SAH in the basal cisterns. Subsequent internal carotid artery angiography demonstrated a small bulge on the superior wall of the horizontal (M1) segment of the middle cerebral artery. However, a pterional craniotomy revealed a well-circumscribed solitary tumor with a diameter of 15 mm involving the superior wall of the M1 segment as the cause of the SAH. Pathological examination demonstrated typical findings of a schwannoma, elongated cells with tapered, spindle-shaped nuclei and indistinct cell borders, and diffuse immunoreactivity for the S100 protein.

Thoracic Saccular Aortic Aneurysm Presenting with Recurrent Laryngeal Nerve Palsy prior to Aneurysm Rupture: A Prodrome of Thoracic Aneurysm Rupture?

Left recurrent laryngeal nerve palsy rarely results from cardiac disease. We present 2 cases of left recurrent laryngeal nerve palsy caused by thoracic saccular aortic aneurysms. One patient suffered an aortic aneurysm rupture one month after the advent of hoarseness, necessitating emergency surgery with aortic arch replacement. The other patient underwent elective aortic arch replacement surgery. Both saccular aortic aneurysms protruded downward in the aortopulmonary window to compress the recurrent laryngeal nerves. This is only the 5th case report of the rare occurrence of acute recurrent laryngeal nerve palsy subsequent to saccular aneurysm rupture in the English literature. Recurrent laryngeal nerve palsy does not always indicate imminent aneurysm rupture, but should trigger awareness of a potential rupture in the near future. Left recurrent laryngeal nerve palsy might be a prodrome of aneurysm rupture.

Moyamoya disease presenting with subarachnoid hemorrhage localized over the frontal cortex: case report

Background In moyamoya disease, intracranial bleeding is known to occur because of the rupture of saccular aneurysms in the circle of Willis or because of the rupture of dilated, fragile moyamoya vessels. The former causes subarachnoid hemorrhage (SAH), and the latter causes intracerebral or intraventricular hemorrhage. Case description In this report, we describe the case of a 34-year-old woman with moyamoya disease who suddenly developed headache and jacksonian seizure. Plain computed tomographic scans on admission revealed SAH localized over the left frontal cortex. The patient was diagnosed with moyamoya disease on cerebral angiography. However, no aneurysm was found on cerebral angiography. Positron emission tomography showed the reduction of CBF and its reactivity to acetazolamide and the elevation of CBV in the left hemisphere. She underwent STA to MCA anastomosis and indirect synangiosis. Intraoperative observations revealed that the pial arterioles were markedly dilated on the brain surface. The CBF in the left hemisphere significantly improved after surgery. The patient has experienced no further episode of cerebral ischemia or intracranial bleeding. Conclusions Subarachnoid hemorrhage of unknown cause is quite rare in moyamoya disease. Based on the findings in the present case, the dilated collateral arteries on the brain surface may rupture and cause SAH over the cerebral cortex, which is the third cause of intracranial bleeding in patients with persistent cerebral ischemia due to moyamoya disease.

Computed tomography angiography in detection and characterization of ruptured anterior cerebral artery aneurysms at uncommon location for emergent surgical clipping

Introduction Cerebral subarachnoid hemorrhage may result from rupture of saccular aneurysms at uncommon location [excluding the anterior communicating artery (ACOM)] of the anterior cerebral artery (ACA). The purpose of this study was to evaluate the usefulness of helical computed tomography angiography (CTA) in detection and characterization of intracranial aneurysms at such uncommon locations before emergent surgical clipping. Materials and methods Between 1998 and 2003, records for 50 consecutive patients who underwent emergent surgical clipping for intracranial aneurysms were reviewed. Eighteen of these patients had aneurysms in the ACA. After those patients with unequivocal ACOM aneurysms were excluded, eight patients with eight aneurysms in an uncommon location of the ACA were recruited to this study. Plain computed tomography (CT) and CTA were performed in eight patients, and digital subtraction angiographies were done in three patients. Each aneurysm was evaluated for the detection, quantification, and characterization of the aneurysms with 2D multiplanar reformatted and 3D volume-rendering techniques. Results There were two small aneurysms arising from the A1 segment, one from the A2 segment, two at the junction of triplicated ACAs, two at the junction of A2 and A3 segments, and one at the junction of A2 and A3 segments of the azygos ACA. The average diameter of the aneurysmal sac was 4.44 mm (range, 2.7–7.0 mm), and the aneurysmal neck averaged 2.59 mm (range, 1.2–3.5 mm) in size. The smallest aneurysm measured 2.2×1.8×2.7 mm (neck, 1.2 mm) in the A1 segment of the left ACA. Three patients had intracerebral hematoma, seven had intraventricular hemorrhage, and three had acute hydrocephalus. Conclusion Aneurysms in uncommon locations of ACAs exhibited characteristic features. Rupture of these aneurysms can cause intracerebral hematoma, intraventricular hemorrhage, and/or acute hydrocephalus. Noninvasive CTA can reliably detect and characterize intracranial aneurysms at such uncommon location for planning of emergent surgical intervention.

Rupture of aorta arch aneurysm into the lung with formation of pseudoaneurysm

To improve the early diagnosis and avoid preoperative misdiagnosis, we discuss some of the diagnostic problems related to thoracic saccular aneurysm rupture into the lung. A case report is presented. We report on a patient with rupture of aorta arch aneurysm into the lung with formation of pseudoaneurysm accompanied with left upper lobe atelectasis, who simultaneously underwent a left upper lobectomy, aneurysmectomy and aorta arch neoplasty. The few cases described in the literature are reviewed to discuss the difficulties of differential diagnosis of left lung mass. The diagnosis methods and operation treatment of the aorta aneurysm are discussed. Angiography and CT are effective diagnostic methods of aorta aneurysm. These data suggest that it is an effective method of aneurysmectomy with/without left pneumonectomy or lobectomy to treat aneurysm of thoracic aorta.

Mathematical model of the rupture mechanism of intracranial saccular aneurysms through daughter aneurysm formation and growth

Objectives: Daughter aneurysms have been strongly associated with saccular aneurysm rupture. We constructed a mathematical model to help explain this association as a possible hemodynamic mechanism for intracranial saccular aneurysm rupture.Methods: Our model is based on the assumption that when an aneurysm reaches a state of imminent rupture, the weakest area of the aneurysm wall responds passively to a surge of intra-aneurysmal pressure by forming a daughter aneurysm that will be the site of the eventual rupture. The daughter and parent aneurysms were assumed to be spherical. Using mathematical modeling, the growth of the daughter aneurysm was observed. To obtain the change in tensile stress in the daughter aneurysm wall under constant pressure and changing geometry, the Law of Laplace was applied to the parent and the daughter aneurysms.Results: The model reveals that the stress factor, i.e. tensile stress in the daughter aneurysm wall relative to the wall strength (rupture point), is dependent on two geometric parameters: the orifice factor (μ), which represents the relative size of the daughter aneurysm orifice radius to the parent aneurysm radius; and the aspect ratio (λ), which represents the height-to-orifice ratio of the daughter aneurysm. As the daughter aneurysm develops, the stress factor first decreases to protect against rupture. Minimal stress is attained at an aspect ratio (λ) of 0.577 regardless of the orifice factor. This is a relatively stable state. Further growth of the daughter aneurysm results in an increase of stress above the minimum, eventually leading to rupture at a stress factor of 1. A smaller orifice factor μ allows this aneurysm to grow to a higher aspect ratio λ before rupture.Discussion: Daughter aneurysm formation is a likely path to aneurysm rupture. The formation of a daughter aneurysm temporarily decreases the tensile stress within a parent aneurysm in which rupture is imminent, indicating a temporary protective role of daughter aneurysm development. Aneurysms harboring daughter aneurysms are at a more advanced stage of development, hence at a greater risk for rupture. The severity of the rupture risk can be estimated on the basis of daughter aneurysm geometry; aspect ratio λ> 0.577 indicates a greater risk of rupture. Furthermore, daughter aneurysms with larger orifices are associated with a greater risk of rupture.

303 分岐部に凹部を持つ管内の拍動流れの可視化と流速測定(G05-5 複雑流れ(1),G05 流体工学)

Various studies have been conducted to explain the hydrodynamic causes of origin, growth and rupture of saccular aneurysms. This experimental is performed using a model of saccular aneurysms consisting of an arterial bifurcation of 30° -30° with a sac at the bifurcation. Controlled experimental conditions are the Reynolds number (500,1000,1500), the flow rate ratio, in the arterial bifurcations (5:5, 8:2), the shape of saccular aneurysm and pulsation. The flow construction is stable in the case of not symmetrical flow but asymmetrical flow. The velocity in the saccular aneurysm does not depend on the pulsation under any conditions, and it increases as the Reynolds number increases.

Nonaneurysmal subarachnoid hemorrhage secondary to tuberculous meningitis: report of two cases

Nontraumatic subarachnoid hemorrhage, one of the life-threatening diseases seen in Emergency Departments, is rarely caused by conditions other than rupture of saccular aneurysms. We report two cases of suspected tuberculous meningitis complicated with nonaneurysmal subarachnoid hemorrhage confirmed by conventional cerebral angiography. Tuberculous meningitis should be considered in the differential diagnoses in cases of nonaneurysmal subarachnoid hemorrhage, especially in tuberculosis endemic areas.

Saccular aneurysms in moyamoya disease: Endovascular treatment using electrically detachable coils

Moyamoya disease (MMD) often presents with subarachnoid hemorrhage due to rupture of saccular aneurysms. We describe three patients with cerebrovascular features of MMD in whom four aneurysms of the posterior circulation were endovascularly occluded by electrothrombosis using the recently developed Guglielmi electrically detachable coils (GDC). Near total occlusion was achieved in three aneurysms. Subtotal occlusion was achieved in one aneurysm. This patient developed complications related to the neuroleptic anesthesia administered for the procedure. The particular hazards of anesthesia and aneurysmal surgery in MMD are discussed, and comparison is made with the benefits of using the GDC. Initial experience suggests that this endovascular approach is safe and effective in the treatment of saccular aneurysms in MMD. However, follow-up is necessary to assess long-term persistence of aneurysm obliteration.

A method for temporary and repeated increase of blood pressure in the rat, using intraperitoneal adrenaline injections

In experimental studies, permanent hypertension has been considered to be an important factor in aneurysm formation and growth. However, in clinical studies it has been found that saccular aneurysms often develop and rupture in some patients without persistent hypertension. Environmental events that temporarily and repeatedly increase blood pressure do not take an equivalent length of time in vivo but have been noted as factors in the growth or rupture of saccular aneurysms. In order to test the effect of intermittent blood pressure elevations on saccular aneurysm formation and growth, a reliable method for temporarily and repeatedly increasing blood pressure should be developed first and in this paper, such a model is described. It is based on the intraperitoneal injections of adrenaline in rats, a route which does not seem to have been used so far.