Heightened activation of embryonic megakaryocytes causes aneurysms in the developing brain of mice lacking podoplanin

During early embryonic development in mammals, including humans and mice, megakaryocytes (Mks) first originate from primitive hematopoiesis in the yolk sac. These embryonic Mks (eMks) circulate in the vasculature with unclear function. Herein, we report that podoplanin (PDPN), the ligand of C-type lectin-like receptor (CLEC-2) on Mks/platelets, is temporarily expressed in neural tissue during midgestation in mice. Loss of PDPN or CLEC-2 resulted in aneurysms and spontaneous hemorrhage, specifically in the lower diencephalon during midgestation. Surprisingly, more eMks/platelets had enhanced granule release and localized to the lower diencephalon in mutant mouse embryos than in wild-type littermates before hemorrhage. We found that PDPN counteracted the collagen-1-induced secretion of angiopoietin-1 from fetal Mks, which coincided with enhanced TIE-2 activation in aneurysm-like sprouts of PDPN-deficient embryos. Blocking platelet activation prevented the PDPN-deficient embryo from developing vascular defects. Our data reveal a new role for PDPN in regulating eMk function during midgestation.

To clip or to coil for unruptured intracranial aneurysm?: A protocol of randomized controlled trial

INTRODUCTION

Microsurgical clipping and endovascular coiling are the main methods against unruptured intracranial aneurysm (UIA). The craniotomy of surgical clipping may increase the risk of cerebrospinal fluid leakage and infection, damage the brain tissue, produce excessive stimulation to the nerves and blood vessels around the aneurysm, and cause the corresponding neurological deficit. Endovascular coiling could significantly reduce the mortality and disability rate than surgical clipping technique, which made endovascular coiling to become the first choice for the treatment of UIA. However, the long-term results showed attenuated favorable outcomes of coiling over clipping, so it is still in debate whether to clip or to coil. Therefore, we try to conduct a randomized, controlled, prospective trial to assess the long term safety of endovascular coiling therapy against UIA compared with microsurgical clipping technique.

METHODS

Parallel-group randomization (1:1) is generated through the random number generator in Microsoft Excel 2010. In this trial, blinding to patients, physicians, and outcome assessors is not possible. Endovascular coiling or surgical clipping will be performed once for each patient in treatment group or control group, respectively. The mRS, overall mortality rate, disability rate, morbidity rate, and occurrence of a major aneurysm recurrence measured at 6 month and 1 year will be recorded.

CONCLUSIONS

The findings will be helpful for the choice of endovascular coiling or surgical clipping by assessing the long term efficacy and safety of both operations against UIA.

TRIAL REGISTRATION

OSF Registration number: DOI 10.17605/OSF.IO/QYE9F.

Ruptured Infundibular dilatation of the posterior communicating artery

OBJECTIVE

An infundibulum of the posterior communicating artery (PcomA) or infundibular dilatation (ID) is considered to be a benign anatomical variant. However, some evidence suggests that ID is a pre-aneurysmal state. This case series presents cases of ruptured IDs and aneurysms originating from the IDs.

METHODS

Between April 2002 and June 2020, 1337 patients were treated for aneurysmal subarachnoid hemorrhage (SAH). Among them, 7 patients with ruptured PcomA IDs were identified. Rupture IDs of the PcomA were categorized into 1) direct rupture of IDs, and 2) rupture of aneurysms originating from IDs. The clinical and radiographic factors were retrospectively reviewed.

RESULTS

Two patients experienced direct rupture of IDs, while the other 5 patients presented with ruptured aneurysms originating from IDs. The 2 patients with direct rupture of IDs at presentation were relatively younger (< 50 years), while the other 5 patients with ruptured aneurysms originating from IDs were over 70 and had a history of aneurysmal SAH due to other intracranial aneurysms. Ruptured IDs were treated with microsurgery or endovascular treatment. There were no complications related to the procedure for securing ruptured IDs. Five (71.4%) patients showed favorable outcomes. One patient with initial Hunt and Hess grade 4 died due to initial brain damage with cerebral vasospasm and medical complications.

CONCLUSIONS

ID of the PcomA rarely causes SAH with or without aneurysm formation. Thus, patients with IDs of the PcomA should be carefully followed up for a long period, especially those with a history of aneurysmal SAH.

Rupture of De Novo Middle Cerebral Artery Aneurysm 8 Years After the Clipping of Ruptured M1 Middle Cerebral Artery Aneurysm

BACKGROUND Development and rupture of a de novo intracranial aneurysm is rare. Little is known regarding its etiology and the appropriate timing of follow-up angiograms after surgical clipping or coiling. CASE REPORT We present a case report of a 39-year-old male smoker with history of hypertension who developed a de novo aneurysm 8 years after surgical clipping of an aneurysm in the middle cerebral artery in the same segment. He presented with neck rigidity and drowsiness. Laboratory analysis did not show blood dyscrasia. Brain computerized tomography showed right temporal lobe hematoma and 4-vessel angiogram demonstrated de novo aneurysm in the same segment of the M1 middle cerebral artery, which was confirmed by intraoperative microsurgical findings. We review the literature on such cases and discuss the pathophysiology, diagnosis, and treatment of this condition. De novo aneurysm, although rare, can develop within days to as long as 10 years after surgical clipping or coiling. CONCLUSIONS This rare case of de novo aneurysm supports follow-up imaging of patients after initial surgical clipping for up to 10 years.

[Giant ruptured common femoral artery aneurysm revealing Behçet's disease]

Vascular involvement in Behçet's disease is rare. Aneurysmal arterial involvement is the severe form of the disease, it constitutes a therapeutic challenge given its severity, and frequent secondary complications, especially at anastomosis. The systematic immunosuppressive drug treatment and surgical technique thoroughness can reduce relapse rate. We report the case of a young man in whom a ruptured false aneurysm of the common femoral artery revealed Behçet's disease. He underwent an open repair, with prosthetic arterial reconstruction, and anastomosis reinforcement with teflon.

Morphological variables associated with ruptured basilar tip aneurysms

Morphological factors of intracranial aneurysms and the surrounding vasculature could affect aneurysm rupture risk in a location specific manner. Our goal was to identify image-based morphological parameters that correlated with ruptured basilar tip aneurysms. Three-dimensional morphological parameters obtained from CT-angiography (CTA) or digital subtraction angiography (DSA) from 200 patients with basilar tip aneurysms diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016 were evaluated. We examined aneurysm wall irregularity, the presence of daughter domes, hypoplastic, aplastic or fetal PCoAs, vertebral dominance, maximum height, perpendicular height, width, neck diameter, aspect and size ratio, height/width ratio, and diameters and angles of surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. In multivariable analysis, presence of a daughter dome, aspect ratio, and larger flow angle were significantly associated with rupture status. We also introduced two new variables, diameter size ratio and parent-daughter angle ratio, which were both significantly inversely associated with ruptured basilar tip aneurysms. Notably, multivariable analyses also showed that larger diameter size ratio was associated with higher Hunt-Hess score while smaller flow angle was associated with higher Fisher grade. These easily measurable parameters, including a new parameter that is unlikely to be affected by the formation of the aneurysm, could aid in screening strategies in high-risk patients with basilar tip aneurysms. One should note, however, that the changes in parameters related to aneurysm morphology may be secondary to aneurysm rupture rather than causal.

Risk Factors for Intraprocedural Rerupture during Embolization of Ruptured Intracranial Aneurysms

BACKGROUND

Intraprocedural rupture (IPR) is a devastating complication in endovascular treatment of ruptured intracranial aneurysms, but its risk factors have not been fully assessed. This study was performed to explore the risk factors for IPR during embolization of ruptured cerebral aneurysms.

METHODS

A total of 1,494 patients with ruptured intracranial aneurysms who underwent endovascular interventional embolization were enrolled. Clinical characteristics were collected for each patient. Univariate and multivariate logistic regression analysis was employed to identify the factors independently associated with IPR. A receiver operating characteristic (ROC) curve analysis was performed to determine the cutoff values of continuous variables predicting IPR.

RESULTS

Forty-one patients suffered from IPR (2.7%). Multivariate logistic regression analysis indicated that aneurysm size (odds ratio [OR], 0.819; 95% confidence interval [CI], 0.732-0.916), aneurysms with irregular morphology (OR, 2.162; 95% CI, 1.143-4.091), time from symptom onset to intervention (OR, 1.615; 95% CI, 1.207-2.161), and vasospasm during embolization (OR, 2.021; 95% CI, 1.038-3.934) were the independent risk factors of IPR. ROC curve analysis showed that the area under the curve for aneurysm size and time from onset to intervention were 0.697 (cutoff value, 3.4 mm; sensitivity, 78.8%; and specificity, 53.7%) and 0.659 (cutoff value, 2 days; sensitivity, 78.0%; and specificity, 45.2%), respectively.

CONCLUSION

Aneurysms with irregular morphology, aneurysms ≤ 3.4 mm in diameter, time from onset to intervention > 2 days and cerebral vasospasm during embolization are independent risk factors for IPR during coil embolization of ruptured aneurysms. More attention should be paid to the factors increasing the risk of IPR in patients with ruptured aneurysms so as to minimize this complication.

Ruptured cerebral pseudoaneurysm in an adolescent as an early onset of COVID-19 infection: case report

The clinical manifestations of coronavirus disease 2019 (COVID-19) are non-specific and multi-inflammatory. They vary from mild to severe manifestations that can be life-threatening. The association of SARS-CoV-2 infection and pseudoaneurysm formation or rupture of an already existing aneurysm is still unexplored. Several mechanisms may be involved, including the direct destruction to the artery by the viral infection or through the release of the inflammatory cytokines. We are presenting a case of a 13-year-old girl with a ruptured cerebral pseudoaneurysm of the left middle cerebral artery (M2 segment) with severe intracerebral hemorrhage as the earliest manifestation of COVID-19 infection.

An unusual ischaemic presentation of thrombosed intracranial mycotic aneurysm with subsequent subarachnoid haemorrhage

We present an unusual case of acute ischaemic stroke secondary to thrombosed mycotic aneurysm with subsequent early aneurysmal rupture and subarachnoid haemorrhage, successfully treated with endovascular coil embolisation of the thrombosed segment. Imaging correlates are presented demonstrating successful endovascular management despite vessel occlusion precluding angiographic visualisation of the aneurysmal segment. Imaging and clinical follow-up is provided demonstrating durable occlusion and excellent clinical outcome with full functional recovery.

Ruptured Popliteal Artery Aneurysm Complicated with Acute Respiratory Distress Syndrome Secondary to SARS-CoV-2 Infection

We herein report a rare case of the ruptured popliteal artery aneurysm in an 89-year-old man, whose recovery after surgical treatment was complicated with acute respiratory distress syndrome secondary to confirmed infection with SARS-CoV-2. Presenting symptoms, patient's comorbidities, and postoperative course complicated with cardiac and respiratory failure leading to adverse outcome are discussed in this case report.

Urinary Tract Bleeding as a Rare Manifestation of Uterine Artery Pseudoaneurysm

Pseudoaneurysm of the uterine artery is a rare condition, which usually occurs after a traumatic birth, cesarean section, dilatation and curettage, and hysterectomy. This case is a 28-year-old female patient that presented with the chief complaint of severe urinary tract bleeding and hypovolemic shock. This patient underwent cesarean section 2 months before the first presentation. After the primary examination, the patient was sent to the hybrid operation room with the primary diagnosis of uterine artery pseudoaneurysm and coil embolization was done for treating the pseudoaneurysm. Considering continued bleeding, open surgery was performed and the internal iliac artery was ligated.

Delayed spontaneous rupture of cavernous segment of the internal carotid artery following dual ophthalmic segment aneurysms treatment with pipeline embolization device: A case report

RATIONALE

The incidence of double aneurysms on the ophthalmic segment of the internal carotid artery (ICA) is very rare. Nevertheless, delayed rupture of a parent artery instead of the aneurysmal sac following pipeline embolization device (PLED) is unusual.

PATIENT CONCERNS

We present a 72-year-old female who was admitted at our facility with gradual onset of nonspecific visual changes.

DIAGNOSIS

Conventional angiography revealed 2 aneurysms located at the ophthalmic segment of the left ICA.

INTERVENTIONS

Both aneurysms were successfully treated with PLED.

OUTCOMES

Two months after discharge, the patient was rushed into the emergency with bilateral conjunctival congestion. Computed tomography revealed intracranial hemorrhage at left temporal lobe while digital subtraction angiography established a left direct carotid cavernous fistula. We utilized stent (Solitaire 6*30) assisted coils to occlude the fistula. The patient is well and go about her normal duties.

LESSIONS

Manipulation of the tortuous parent artery resulted in a focal traumatic weakness in the artery and subsequently a delay tear. We are of the view that, endovascular surgeons should be on the lookout for this complication following flow deviation treatment modalities.

Ruptured Distal Superior Cerebellar Artery Aneurysm After Gamma Knife Radiosurgery for Trigeminal Neuralgia: A Case Report and Review of the Literature

BACKGROUND

Intracranial aneurysm formation after Gamma Knife radiosurgery (GKRS) is a rare complication that has only recently been reported in the literature. We report the case of a fatal distal superior cerebellar artery (SCA) aneurysm rupture in a woman treated twice with GKRS for trigeminal neuralgia along with a review of the literature regarding radiation-induced aneurysms.

CASE DESCRIPTION

A 77-year-old white woman with a history of refractory right-sided trigeminal neuralgia treated with GKRS in 2001, and again in 2006 after a relapse, presented to our emergency department with complaints of a sudden-onset severe headache associated with vomiting, right eye vision loss, left-sided facial droop, and left-sided weakness with no history of hypertension or smoking prior to presentation. Initial head computed tomography scan without contrast demonstrated an intraparenchymal hemorrhage centered in the right middle cerebellar peduncle with subarachnoid hemorrhage in the basal cisterns and extension into the fourth ventricle causing early hydrocephalus. Head computed tomography angiography (CTA) demonstrated a distal right SCA aneurysm adjacent to the hemorrhage. The patient's mental status deteriorated into coma after suspected rerupture during the CTA requiring immediate intubation, external ventricular drain placement, and emergent cerebral angiogram with coil embolization. Ultimately, the patient never recovered despite medical and surgical management; therefore, care was withdrawn in accordance with her known wishes.

CONCLUSIONS

The pathophysiologic association of aneurysm formation after GKRS remains to be elucidated, but given the potentially fatal consequences of aneurysm rupture, we advocate for further research and propose serial vascular imaging during the postradiosurgery follow-up period for iatrogenic aneurysm formation surveillance.

An unruptured posterior communicating artery aneurysm ruptured during angiography: A case report

INTRODUCTION

Cerebrovascular imaging is the gold standard for diagnosis of intracranial aneurysms. Rupture of intracranial aneurysm is rare in cerebrovascular angiography, especially in unruptured intracranial aneurysm.

PATIENT CONCERNS

A 74-year-old woman was admitted to the hospital for sudden onset of left eyelid ptosis for 1 day with no obvious inducement. The patient had a history of hypertension. Physical examination revealed that she had clear consciousness and normal speech, but the left eyelid drooped. The left pupil diameter was 5 mm and light reflex was absent. The left eyeball could not move, and the right eye examinations were normal. The limb muscle strength and muscle tension were normal.

DIAGNOSIS

Bilateral internal carotid artery posterior communicating aneurysm, severe stenosis of the origin of left carotid artery, and right oculomotor nerve palsy.

INTERVENTIONS

After the hospital, the aneurysm ruptured and hemorrhaged during radiography, and the patient improved after immediate rescue and treatment. On the third day after angiography, the patient's the condition gradually stabilized. Under the general anesthesia, left carotid artery stenosis stent implantation and left posterior communicating artery aneurysm stent assisted coil embolization were performed successfully. On the second day after embolization, the patient's head computed tomography (CT) showed subarachnoid hemorrhage with hydrocephalus. The patient underwent external ventricular drainage. A month later, the patient underwent ventriculoperitoneal shunt.

OUTCOMES

Six months later, the patient visited our hospital for a follow-up, and she was clear-headed, aphasia, right limb hemiplegia with muscle strength grade II, left side autonomous activities, and the GOS score was 2 points. Head CT showed the ventricles were normal.

CONCLUSIONS

Acute oculomotor palsy may be a risk factor for rupture of ipsilateral unruptured aneurysms, but more basic research and clinical trial evidence of intracranial aneurysms are needed to confirm this.

Fatal Exsanguination Following Rupture of an Iliac Artery Aneurysm in an Infant With Menkes Disease

Menkes disease (MD) usually presents in infancy with respiratory and neurological complications. Severe isolated vasculo-connective tissue involvement in infancy is rare, and hence the precise and timely diagnosis is difficult. We report a case of an 8-week-old male infant who succumbed to acute, severe exsanguination, and hemorrhagic shock secondary to a large retroperitoneal hematoma due to rupture of a right iliac artery aneurysm. Perimortem musculoskeletal findings raised suspicion of nonaccidental injury. However, postmortem review of facial traits raised the suspicion of MD. MD was subsequently confirmed on genetic testing. Child health clinicians must remain aware of MD as a rare cause of infant vasculopathy or atypical skeletal abnormalities.

Rupture of Intradural Giant Aneurysms: The Mode of Treatment, Anatomical, and Mechanical Factors

OBJECTIVE

Aneurysm rupture is often a fatal complication of giant intradural aneurysm (GIA) treatments. The purpose of this study was to review aneurysm rupture in GIA treatment.

MATERIALS AND METHODS

We performed a systematic review on aneurysm rupture related to GIA treatment. For each reported case, we collected the following information: aneurysm location, size and rupture status, the mode of treatment, timing of the hemorrhage, anatomical, and hemodynamic factors.

RESULTS

We identified 56 aneurysm ruptures related to treatment in 38 published studies. Of the nine intraoperative ruptures, eight occurred during endovascular procedures and one in surgical treatment. Of the 47 delayed ruptures, 72.3% occurred within 2 weeks. The prognosis of intraoperative and delayed ruptures was poor, with 83.9% experiencing death. Of these aneurysms, 75% were initially unruptured. Of the delayed ruptured aneurysms, 21.3% had prior surgical treatment, 74.4% had prior endovascular treatment, and 4.3% had prior combined surgical and endovascular treatments. Vertebrobasilar artery (VBA) location was significantly associated with aneurysm rupture after treatment, occurring at 57.2%. Flow diverter (FD) treatment seemed to elevate the delayed rupture proportion of giant paraclinoid internal carotid artery (ICA) aneurysms from 22.0% to 42.9%. FD treatment did not lower the rupture risk of giant VBA aneurysms and the corresponding death rate.

CONCLUSION

Intraoperative and delayed aneurysm ruptures were the most challenging in endovascular treatment of GIAs. Giant VBA aneurysm had the highest rupture risk after treatment. FD seemed to elevate the delayed rupture proportion of giant paraclinoid aneurysms.

[A jejunal artery pseudoaneurysm ruptured in the jejunal lumen: A rare vascular complication of severe pancreatitis]

Jejunal pseudoaneurysm is a rare complication of pancreatitis, usually manifested by digestive bleeding when it ruptures into the digestive lumen. This complication is extremely rare and may be life-threatening. The diagnosis is based on abdominal angiographic computed tomography. Radiology allows therapeutic management through arterial embolization. This case report describes a pseudoaneurysm of jejunal artery that developed as the result of pancreatitis: A 77-year-old man seen in early September 2015 at the emergency department for acute pancreatitis had a pseudocyst infected and spontaneously fistulized into the jejunum lumen. His condition responded initially to symptomatic therapy, and he was discharged. He returned two years later, with digestive bleeding from jejunal pseudoaneurysm that had ruptured into the jejunal lumen. Angiographic embolization was performed as first-line treatment with good outcome. Bleeding more than two years after acute pancreatitis due to rupture of a jejunal pseudoaneurysm is an exceptional complication. Here we report a rare case of digestive hemorrhage caused by jejunal pseudoaneurysm, complicating acute pancreatitis.

The PHASES score: To treat or not to treat? Retrospective evaluation of the risk of rupture of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The PHASES score was formulated to predict the 5-year risk of rupture for intracranial aneurysms. We retrospectively analyzed all patients treated in our institution for aneurysmal SAH and applied the PHASES score to estimate the probable predicted risk of bleeding in this group of patients.

METHODS

Between February 2015 and August 2018, all patients with aneurysmal SAH were retrospectively analyzed and the PHASES score was applied. A total of 155 patients were included with a mean age of 53.8years, including 60 males and 95 females.

RESULTS

Of our patients 110 (70.9%) had a PHASES score of below or equal to 5, with a hemorrhagic risk of up to 1.3% over 5years. If we analyze the patients with a risk of below 2% this figure increases to 122 patients (78.7%). Of these 99.3% were European and 0.6% were Japanese (1 patient). In 86 patients (55.4%), the aneurysm was smaller than 5mm and in 10 patients (6.4%) the aneurysm was located in the posterior circulation.

CONCLUSION

Of our patients 78.7% had less than a 2% 5-year rupture risk based on their PHASES score, highlighting the discrepancy of the rupture risk calculated with the PHASES score when hypothetically applied to this group of patients. In the hypothetical scenario that our patients had unruptured aneurysms, our retrospective analysis shows that the PHASES score may only provide a weak tool for clinicians to use in the decision-making process as to whether or not to treat these aneurysms.

Hyper-dense fluid on plain computed tomography may reveal a ruptured aneurysm in patients with median arcuate ligament syndrome

Rupture of abdominal aneurysms associated with median arcuate ligament syndrome (MALS) is a serious condition and requires accurate diagnosis in a clinical setting. We examined three patients with this condition: two women aged 45 and 71 years, and a 61-year-old man. They complained of abdominal pain and had fluid collection around the duodenum. Plain computed tomography (CT) of the fluid collection revealed hyper density, which suggests the presence of blood. Moreover, contrast-enhanced CT revealed aneurysms in the pancreatic head area. Angiography revealed aneurysms of the branches of the gastroepiploic artery, which were treated by endovascular embolization in all patients. Thus, patients with abdominal pain and high-density fluid collection around the duodenum on plain CT may suffer from hemorrhage following rupture of MALS-associated aneurysms.

Ruptured Berry Aneurysm as the initial presentation of Polycystic Kidney Disease: A case report and review of literature

Intra-cranial saccular aneurysms, also known as Berry aneurysms, have a well-known association with autosomal dominant polycystic kidney disease (ADPKD). Aneurysmal rupture can be the initial presentation of the disease. ADPKD has two types of gene mutations: PKD1 and PKD2. The latter one is of a milder form presenting later in life. Imaging plays a crucial role in the diagnosis and assessment in order to provide adequate management of these patients however, there are no official standardized guidelines established for screening of these intracranial aneurysms.

Cavernous sinus aneurysms: risk of growth over time and risk factors

OBJECTIVE

Cavernous internal carotid artery (ICA) aneurysms are frequently diagnosed incidentally and the benign natural history of these lesions is well known, but there is limited information assessing the risk of growth in untreated patients. The authors sought to assess and analyze risk factors in patients with cavernous ICA aneurysms and compare them to those of patients with intracranial berry aneurysms in other locations.

METHODS

Data from consecutive patients who were diagnosed with a cavernous ICA aneurysm were retrospectively reviewed. The authors evaluated patients for the incidence of cavernous ICA aneurysm growth and rupture. In addition, the authors analyzed risk factors for cavernous ICA aneurysm growth and compared them to risk factors in a population of patients diagnosed with intracranial berry aneurysms in locations other than the cavernous ICA during the same period.

RESULTS

In 194 patients with 208 cavernous ICA aneurysms, the authors found a high risk of aneurysm growth (19.2% per patient-year) in patients with large/giant aneurysms. Size was significantly associated with higher risk of growth. Compared to patients with intracranial berry aneurysms in other locations, patients with cavernous ICA aneurysms were significantly more likely to be female and have a lower incidence of hypertension.

CONCLUSIONS

Aneurysms of the cavernous ICA are benign lesions with a negligible risk of rupture but a definite risk of growth. Aneurysm size was found to be associated with aneurysm growth, which can be associated with new onset of symptoms. Serial follow-up imaging of a cavernous ICA aneurysm might be indicated to monitor for asymptomatic growth, especially in patients with larger lesions.

Post-Complex Myocardial Infarct Pseudoaneurysm Rupture and Subsequent Complications

Ventricular pseudoaneurysm is an uncommonly encountered complication of myocardial infarction (MI) in the era of percutaneous coronary intervention. Its presentation can be very non-specific, and diagnosis requires a high index of suspicion. Urgent surgical repair is generally warranted to prevent potentially catastrophic complications. We present a case of patient who presented several days after his index MI. He was ultimately diagnosed with a ruptured pseudoaneurysm, and despite best efforts had a complicated hospital course.

Spontaneous Accessory Renal Artery Aneurysm Rupture in a Patient With Neurofibromatosis Type 1: A Case Report

True renal artery aneurysms are rare. Ruptured aneurysms are even rarer but can have devastating consequences. Renal artery aneurysms most commonly occur in patients with hypertension, atherosclerosis, or fibromuscular dysplasia. Treatment options can range from embolization to nephrectomy. We describe an interesting case of spontaneous accessory renal artery aneurysm rupture in a 44-year-old female with neurofibromatosis type 1 (NF1) who otherwise had no medical problems. She was successfully treated with selective coil embolization, recovered without complications, and maintained preoperative renal function.

Clipping of Ruptured Aneurysm of Lateral Spinal Artery Associated with Anastomosis to Distal Posterior Inferior Cerebellar Artery: A Case Report

BACKGROUND

Arteries that anastomose with the posterior inferior cerebellar artery (PICA) can harbor aneurysms.

CASE DESCRIPTION

We present a case of a patient who suffered a subarachnoid hemorrhage as a result from an aneurysm on the left lateral spinal artery (LSA) that anastomosed to the PICA. The aneurysm was treated surgically, and the flow between the LSA and PICA was disrupted. The activated anastomotic network created a new anastomosis between the LSA and PICA, which was seen at 6 months' follow-up.

CONCLUSIONS

Careful follow-up is warranted in patients who have an activated anastomotic network because they can potentially develop aneurysms on newly created anastomoses.