Dysbiosis of Gut Microbiome Is Associated With Rupture of Cerebral Aneurysms.

BACKGROUND AND PURPOSE: Environmental factors are important with respect to the rupture of cerebral aneurysms. However, the relationship between the gut microbiome, an environmental factor, and aneurysm rupture is unclear. Therefore, we compared the gut microbiome in patients with unruptured intracranial aneurysms (UIAs) and ruptured aneurysms (RAs) to identify the specific bacteria causing the rupture of cerebral aneurysms. METHODS: A multicenter, prospective case-control study was conducted over one year from 2019 to 2020. The fecal samples of patients with stable UIAs and RAs immediately after onset were collected. Their gut microbiomes were analyzed using 16S rRNA sequencing. Subsequently, a phylogenetic tree was constructed, and polymerase chain reaction was performed to identify the specific species. RESULTS: A total of 28 RAs and 33 UIAs were included in this study. There was no difference in patient characteristics between RAs and UIAs: age, sex, hypertension, dyslipidemia, diabetes status, body mass index, and smoking. No difference was observed in alpha diversity; however, beta diversity was significantly different in the unweighted UniFrac distances. At the phylum level, the relative abundance of Campylobacter in the RA group was larger than that in the UIA group. Furthermore, the gut microbiome in the RA and UIA groups exhibited significantly different taxonomies. However, Campylobacter was focused on because it is widely known as pathogenic among these bacteria. Then, a phylogenetic tree of operational taxonomic units related to Campylobacter was constructed and 4 species were identified. Polymerase chain reaction for these species identified that the abundance of the genus Campylobacter and Campylobacter ureolyticus was significantly higher in the RA group. CONCLUSIONS: The gut microbiome profile of patients with stable UIAs and RAs were significantly different. The genus Campylobacter and Campylobacter ureolyticus may be associated with the rupture of cerebral aneurysms.

A Case Report: Ruptured Popliteal Aneurysm Caused by Haemophilus Influenzae Infection.

Mycotic aneurysms arise from infection of an arterial wall secondary to septic emboli from endocarditis. Although rare, most mycotic aneurysms involve the abdominal aorta, with Staphylococcus aureus and Salmonella spp being the most common causative organisms. We report a case of an 81-year-old woman with a ruptured mycotic popliteal aneurysm from Haemophilus influenzae infection.

Utility of Susceptibility-Weighted Angiography Sequence in the Diagnosis of Ruptured Infectious Aneurysms.

In a patient with infective endocarditis (IE), susceptibility-weighted angiography (SWAN) sequence revealed 2 intracranial infectious aneurysms (IIAs) as bright signal lesion, related to the high-velocity arterial flow within the IIAs. In addition, SWAN revealed a convexal subarachnoid hemorrhage-related to distal IIA rupture-as a dark signal. The risk of IIA rupture emphasizes the need for serial imaging follow-up in patients with IE receiving antibiotic therapy after endovascular treatment and after valve surgery. Considering its specific risks, particularly in patients with IE who may be on anticoagulation, digital subtraction angiography is not used routinely in this context. Therefore, SWAN might be an alternative method for selecting patients with IE who need conventional angiography and might be useful for serial follow-up and monitoring after treatment. Future studies should investigate the role of SWAN for the detection of IIAs.

Role of oral pathogens in the pathogenesis of intracranial aneurysm: review of existing evidence and potential mechanisms.

Degeneration of intracranial aneurysm wall is under active research and recent studies indicate an increased risk of rupture of intracranial aneurysm among patients with periodontal diseases. In addition, oral bacterial DNA has been identified from wall samples of ruptured and unruptured aneurysms. These novel findings led us to evaluate if oral diseases could predispose to pathological changes seen on intracranial aneurysm walls eventually leading to subarachnoid hemorrhage. The aim of this review is to consider mechanisms on the relationship between periodontitis and aneurysm rupture, focusing on recent evidence.

Endovascularly Treated Superficial Femoral Artery Aneurysm Rupture Secondary to Campylobacter fetus Bacteremia: A Case Report.

Degenerative aneurysms of the superficial femoral artery (SFA) are relatively rare and often recognized when they become symptomatic such as rupture. Infected SFA aneurysms are much rarer, especially those caused by Campylobacter fetus bacteremia. We report a case of a 67-year-old woman referred to our hospital owing to the presence of a painful reddish swelling on her left thigh. A huge SFA aneurysm rupture was diagnosed, and endovascular treatment with a covered stent was performed. C. fetus was detected in the blood culture thereafter, and antibacterial therapy was successfully performed without any additional surgical interventions. She remained well without any evidence of indolent infection 19 months after the endovascular treatment. The endovascular approach with appropriate prolonged antibacterial therapy would be a feasible alternative for managing selected infected aneurysm cases.

The "connecting vessel" sign: an imaging biomarker to differentiate ruptured infected (mycotic) intracranial aneurysm mimicking the CTA spot sign.

PURPOSE: Infected (mycotic) intracranial aneurysms (IIA) are a prevalent source of morbidity in patients with systemic infection. Unlike saccular aneurysms, ruptured IIA frequently presents with intracerebral hemorrhage (ICH), and the appearance of ruptured IIA on CTA overlaps with the CTA "Spot Sign" (SS), an imaging finding in non-infectious, spontaneous ICH. The purpose of this study was to investigate the imaging and clinical features which may differentiate these two entities on CTA for which treatment strategies differ substantially. METHODS: In an IRB-approved, retrospective case series, we compared 14 patients with confirmed IIA and 14 patients with positive SS due to other non-infectious etiology (SS(+) ICH). Clinical history, laboratory studies, and CTA reports and images were reviewed to define imaging characteristics of IIA and SS(+) ICH, including the diagnostic criteria for SS used in clinical trials. RESULTS: A total of 7/14 patients (50.0%) diagnosed with IIA had ICH at presentation. Of these, 3/7 patients (42.9%) with ruptured IIA and ICH met diagnostic imaging criteria of SS. The remaining 4/7 patients did not meet criteria due to presence of a connecting vessel. Compared with SS(+) ICH of non-infectious etiology, patients with ruptured IIA were younger (40.7 vs. 66.4 years) and had higher rates of IVDU and bacteremia (p < 0.01) and lower rates of hypertension (p < 0.01). Hematoma volume was similar in both groups, but lobar location was more frequent in ruptured IIA (p = 0.06). Mortality at 1 year from diagnosis was equally high in both groups (42.9%). CONCLUSION: This study characterizes ruptured IIA as an imaging mimic of SS and provides a framework for differentiating these lesions, allowing prompt diagnosis and appropriate treatment.

Streptococcus pneumoniae as a Cause of Mycotic and Infected Aneurysms in Patients without Respiratory Features: Challenging Diagnoses Aided by 16S PCR.

BACKGROUND: Streptococcus pneumoniae is considered a rare cause of mycotic aneurysms. The microbiological diagnosis of mycotic aneurysms can be difficult, and many patients have negative blood culture results. METHODS: We describe a series of four consecutive cases of mycotic aneurysms caused by S. pneumoniae with no respiratory features or extravascular septic foci. In two patients with negative blood culture results, 16S PCR was used for the diagnosis of S. pneumoniae infection. RESULTS: Four men with mycotic aneurysms affecting the aorta, axillary, and popliteal arteries caused by S. pneumoniae presented to our center between 2015 and 2016. All were treated with at least one month of intravenous antibiotics, followed by at least 4 weeks of oral antibiotics. Two were additionally managed using endovascular surgical techniques, and one underwent an open surgical repair. The fourth patient presented with bilateral popliteal aneurysms, one of which ruptured and was managed using surgical ligation and bypass, whereas the other side subsequently ruptured and was repaired endovascularly. Three of the four patients are currently off antibiotics and considered cured, while one died of an unrelated cause. CONCLUSIONS: S. pneumoniae should be considered a potential causative agent of mycotic aneurysms. Diagnosis can be confirmed using 16S PCR, especially in patients where peripheral blood cultures are uninformative.

[Surgical treatment of a ruptured aneurysm of the left common iliac artery in a patient with miliary tuberculosis]. / Traitement chirurgical d'un anévrisme rompu de l'artère iliaque commune gauche chez un patient présentant une tuberculose miliaire.

Tuberculous aneurysms of the common iliac artery are rare. Only a few cases have been reported in the literature. We report a new case in a 47-year-old man admitted for abdominal pain and persistent fever. The aneurysm was evoked in the duplex ultrasound scan and confirmed by computed tomographic angiography. The patient underwent an extra-anatomic femorofemoral bypass with a dacron prosthesis and ligation of the aneurysmal artery. The postoperative course was marked by febrile dyspnea related to the tuberculous miliary found on the chest x-ray. Histological analysis of the operative specimens confirmed the tuberculous origin of the aneurysm. The patient was put on antituberculous drugs and the follow-up was uneventful. With a follow-up of four months, the patient was asymptomatic and the bypass was well patent.

Ruptured Syphilitic Aneurysm: A Cause of Sudden Death in a Man with Human Immunodeficiency Coinfection.

Syphilis, a sexually transmitted infection caused by the bacterium Treponema palladium, is experiencing a worldwide resurgence. The risk of syphilis infection is particularly high in men who have sex with men (MSM), especially those who are human immunodeficiency virus (HIV)-positive. Untreated syphilis can lead to rare but severe late-stage complications, including syphilitic aortitis. Herein, we present an autopsy case of a ruptured thoracic aneurysm that resulted from an undetected case of syphilitic aortitis in an HIV-positive Japanese MSM with undiagnosed syphilis. Although no syphilitic skin lesions were observed on the body, anatomical changes consistent with a syphilitic etiology were present at the site of the rupture, including medial aortic scarring with "tree-bark"-like atherosclerotic plaque. In addition, heart blood was positive for T. palladium in a latex agglutination test. This case highlights for forensic pathologists the importance of recognizing syphilis as a possible underlying cause of sudden death among HIV-positive MSM.

Mycotic intracranial aneurysms rupture presenting as pure acute subdural hematoma in infectious endocarditis. Report of 2 cases and review of the literature.

Acute subdural hematoma (ASDH) revealing mycotic aneurysm (MA) is an exceptional occurrence. We report 2 cases of MA-related pure ASDH in the course of infective endocarditis (IE) without history of head trauma, hypertension or coagulopathy. Case 1: A 54-year-old man presented with a 10-day history of headache, fever. At admission neurologic examination and Brain-CT were normal. Blood cultures showed Streptococcus bovis. MRI 5 days later revealed ischemic spots and minime ASDH over the right convexity. Cerebral angiography, revealed a 3 mm saccular aneurysm at the bifurcation of a distal branch of the right posterior cerebral artery (PCA). Case 2: A 42-year-old man presented with a 8-day history of fever, and worsening headache. Mitral regurgitation was evidenced. A methicillin-sensitive staphylococcus aureus left-sided IE was diagnosed. Pre- and post-contrast Brain-CT were normal. He presented 15 days later a secondarily generalized status epilepticus. Brain CT showed an ASDH over the convexity with falco-tentorial extension, midline shift and temporal herniation. It was removed in emergency. Cerebral angiography revealed a MA of a peripheral branch of the left PCA. The 2 patients were successfully treated by endovascular glue embolization and recovered without complications. Even rare, ruptured MA should be considered as a cause of pure ASDH of unknown origin. As MA can be missed on CT- and MR-Angiography because of mass effect, cerebral angiography may be mandatory.

Emergency brachial artery ligation for ruptured infected pseudoaneurysm of haemodialysis access is a possible option.

BACKGROUND: For patients with end-stage renal disease, a good vascular access is essential for chronic haemodialysis. Surgically created access arteriovenous fistula for haemodialysis is associated with multiple complications, and ruptured pseudoaneurysm being the most life threatening and dreaded of all. The management of this complication warrants emergency procedure, although timely diagnosis and arteriovenous fistula salvage has been emphasised. In this study, we describe the surgical technique and outcomes of ligation of the proximal arteriovenous fistula as a plausible alternative and life-saving procedure. METHOD AND RESULTS: This is a retrospective study performed between January 2011 and December 2016. A total of 588 native arteriovenous fistula-related surgeries were performed, of which 18 patients (3.06%) developed delayed complication of infected pseudoaneurysm and rupture. All presented to the emergency care with life-threatening bleeding. We describe the surgical technique as a life-saving measure to this fatal complication. CONCLUSION: Proximal arteriovenous fistula has higher incidence of aneurysmal complications than distal ones. Ligation of the brachial artery which was a 'grey zone' of unpredictable prognosis has yielded good results and can be safely performed in desperate situations with low complication rates.

Systematic Review of Endovascular, Surgical, and Conservative Options for Infectious Intracranial Aneurysms and Cardiac Considerations.

INTRODUCTION: With rising rates of intravenous drug use, Infectious Intracranial aneurysms (IIAs) are a relevant topic for investigation. We performed a systematic review to better understand current practice patterns and limits of current published literature. METHOD: 131 publications with a total of 499 patients (665 aneurysms) were included. Of the 499 patients, 83 were single case reports, and 20.5% of the total had multiple aneurysms. 35.8% of all aneurysms were ruptured. Of those reporting treatment, options included conservative antibiotic therapy (30.0%), open surgical intervention (31.1%), and endovascular occlusion (31.8%). Chronologically, publication of IIAs has increased. Usage of endovascular therapies has grown, while conservative and surgical management have declined in the literature. Overall, 56.2% of aneurysms for which conservative therapy was initiated eventually either underwent intervention or death of patient occurred. RESULTS: The issue of cardiac valve surgery in relationship to aneurysm therapy was discussed in 20.8% (80 patients) of all 384 infectious endocarditis patients; of which 15.0% (12) underwent valve surgery before aneurysm treatment and 85.0 patients (68)% underwent valve surgery after aneurysm treatment. For 51 of the patients where valve surgery followed aneurysm management, the corresponding aneurysm treatment modality could be determined; 58.8% (30) of whom were managed endovascularly. 32.7% (26) of all cases reporting cardiac surgery details underwent cardiac surgery during their admission with the IIA. CONCLUSIONS: Overall, increasing trend of endovascular management of IIAs is evident, and a strong temporal preference exhibited by providers to perform cardiac surgery subsequently to IIA management.

Ruptured Iliac Pseudoaneurysm after Intravesical Bacillus Calmette-Guérin: Urgent Endovascular Treatment. Case Report and Literature Review.

BACKGROUND: Ruptured mycotic aneurysms are an extremely rare complication of intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. Several cases involving various arterial sites, mostly in the thoracic or abdominal aorta, have been described in the literature. BCG immunotherapy rarely causes false aneurysms and open surgical repair using an in situ prosthetic graft is most commonly performed. Further to this, targeted antituberculous treatment is required for at least one year following surgery. METHODS: A 69-year-old man presented at our clinic with fever, lower back pain and malaise. One year before admission he was treated, again, with intravesical BCG for recurrence of a carcinoma. RESULTS: A large infected pseudoaneurysm of 115mm was treated with the implantation of an aortouniiliac endoprosthesis followed by a crossover femoro-femoral bypass and surgical resection of the mass via an retroperitoneal approach. CONCLUSIONS: Endovascular repair can be considered a valid option in an emergency. A hybrid approach was chosen due to the need for urgent action and the poor condition of the patient who was haemodynamically unstable. In particular, the implantation of an aortouniiliac endoprosthesis at the level of the contralateral iliac axis allowed us to avoid the release of an endoprosthesis at the infected area level. Close patient follow-up with clinical evaluation every three months and a CT-scan yearlyis mandatory following the intervention and during antibiotic therapy. A systematic review of the literature has been subsequently carried out on this specific clinical case, highlighting 47 cases described from 1988. CASE REPORT: A large infected pseudoaneurysm of 115 mm presented at our clinic was treated with the implantation of an aortouniiliac endoprosthesis followed by a crossover femoro-femoral bypass and surgical resection of the mass via a retroperitoneal approach. CONCLUSIONS: Endovascular repair can be considered a valid option in an emergency. A hybrid approach was chosen due to the need for urgent action and the poor condition of the patient who was hemodynamically unstable. In particular, the implantation of an aortouniiliac endoprosthesis at the level of the contralateral iliac axis allowed us to avoid the release of an endoprosthesis at the infected area level. Close patient follow-up with clinical evaluation every 3 months and a computed tomography scan yearly is mandatory following the intervention and during antibiotic therapy. A systematic review of the literature has been subsequently carried out on this specific clinical case, highlighting 47 cases described from 1988.

Psoas abscess after bacille Calmette-Guérin instillations causing iliac artery contained rupture.

Intravesical administration of bacille Calmette-Guérin (BCG) is considered to be the therapy of choice for treating superficial bladder carcinoma. Created from a live attenuated strain of Mycobacterium bovis, BCG is theoretically unable to cause infections. However, both local and systemic complications due to infection are known to arise, including vascular complications. We describe the case of a patient with a history of BCG instillations presenting with an arterial rupture of his left iliac artery due to an abscess in the iliopsoas muscle.

Fatal rupture of a mycotic aneurysm of the right coronary artery post pneumococcal sepsis.

Aneurysms of the coronary arteries are rare and mycotic coronary aneurysms are even rarer. We report a unique, yet unfortunately autopsy-proven fatal case of a ruptured atherosclerotic mycotic aneurysm of the right coronary artery with streptococcus pneumoniae in a non-immunocompromised patient resulting in cor tamponade and death.

Successful coil embolization of a ruptured mycotic aneurysm that developed three days after septic embolic infarction: Case report and review of the literature.

BACKGROUND: Infectious intracranial aneurysms (IIAs) are rare entities and are often associated with septic embolus from infectious endocarditis. They may develop rapidly and carry a higher risk of rupture and mortality compared to noninfectious aneurysms. However, the development and rupture of an IIA within 48h in a patient with septic infarction patient is exceedingly rare. CASE DESCRIPTION: In this report, we describe a 25-year-old male who presented with left-sided hemiparesis and dysarthria from septic embolus to the right middle cerebral artery. Thirty-nine hours after presentation, he became encephalopathic following a witnessed seizure. Angiography demonstrated a new, ruptured aneurysm, which was successfully treated with endovascular coil embolization. Our study documents the first report of coil embolization in a rapidly developed infectious aneurysm. CONCLUSIONS: Importantly, this case demonstrates that septic infarction may precede and herald IIA development and rupture. If IIA is detected due to rupture, coil embolization can be a safe and effective therapy.