Neuropsychological outcomes in patients with ruptured anterior communicating artery aneurysms treated by clipping versus coiling: a systematic review and meta-analysis.

Ruptured anterior communicating artery (ACoA) aneurysms are frequently associated with neuropsychological deficits. This review aims to compare neuropsychological outcomes between surgical and endovascular approaches to ACoA. We systematically searched PubMed, Embase, and Web of Science for studies comparing the endovascular and surgical approaches to ruptured ACoA aneurysms. Outcomes of interest were the cognitive function, covered by memory, attention, intelligence, executive, and language domains, as well as motor and visual functions. Nine studies, comprising 524 patients were included. Endovascularly-treated patients showed better memory than those treated surgically (Standardized Mean Difference (SMD) = -2; 95% CI: -3.40 to -0.61; p < 0.01). Surgically clipped patients had poorer motor ability than those with coiling embolization (p = 0.01). Executive function (SMD = -0.20; 95% CI: -0.47 to 0.88; p = 0.55), language (SMD = -0.33; 95% CI: -0.95 to 0.30; p = 0.30), visuospatial function (SMD = -1.12; 95% CI: -2.79 to 0.56; p = 0.19), attention (SMD = -0.94; 95% CI: -2.79to 0.91; p = 0.32), intelligence (SMD = -0.25; 95% CI: -0.73 to 0.22; p = 0.30), and self-reported cognitive status (SMD = -0.51; 95% CI: -1.38 to 0.35; p = 0.25) revealed parity between groups. Patients with ACoA treated endovascularly had superior memory and motor abilities. Other cognitive domains, including executive function, language, visuospatial function, attention, intelligence and self-reported cognitive status revealed no statistically significant differences between the two approaches. Trial Registration PROSPERO (International Prospective Register of Systematic Reviews) CRD42023461283; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=461283.

Deleterious effects of benzotriazoles on zebrafish development and neurotransmission: 5-Chloro-benzotriazole versus 1H-benzotriazole.

Benzotriazoles are heterocyclic compounds typically presenting a benzene ring fused with a triazole molecule. The industry uses these compounds as anti-corrosion agents and recently, they have been employed in the pharmaceutical industry and in detergent formulations. Benzotriazoles persist in the environment, and water treatment plants cannot degrade them completely. Consequently, these compounds have been detected in rivers, lakes, and drinking water, which makes assessing their safety for the human and aquatic animal populations crucial. Here, we have evaluated and compared how exposure to 1H-benzotriazole or 5-chloro-benzotriazole affect the zebrafish embryo-larval stages. We have determined the acute toxicity, morphometric alterations, and acetylcholinesterase activity on zebrafish embryos, as well as behavioral endpoints using the tail coiling assay. The estimated LC50 of 5-chloro-benzotriazole was 19 mg/L, whereas 1H-benzotriazole caused no mortality. The zebrafish embryos exposed to 20 and 25 mg/L 5-chloro-benzotriazole had decreased hatching rate and exhibited pericardial and yolk sac edemas. Furthermore, the embryo length and eye area were decreased, in contrast with an increased yolk sac after exposure to 20 mg/L 5-chloro-benzotriazole. In turn, 1H-benzotriazole also decreased the eye area of zebrafish embryos, but no other significant morphological alterations were observed. The tail coiling assay showed that the zebrafish embryos increased the percentage of time moving and the number of embryonic movements per minute after exposure to 1H-benzotriazole (15 mg/L) or 5-chloro-benzotriazole (20 and 25 mg/L), indicating that these compounds were potentially neurotoxic. However, acetylcholinesterase activity was not significantly altered in embryos exposed to 1H-benzotriazole, but significantly decreased when exposed to 0.05 mg/L 5-chloro benzotriazole confirming its neurotoxicity at a much lower concentration. Our findings showed that 5-chloro-benzotriazole seems to induce more harmful alterations to zebrafish embryos than 1H-benzotriazole. Nevertheless, 1H-benzotriazole seems to induce a direct effect on eye development for concentrations lower than the ones of 5-chloro-benzotriazole affecting zebrafish embryos.

Endovascular trends in the treatment of intracranial aneurysms in a Peruvian reference center.

Objectives: Endovascular treatment of intracranial aneurysms (IAs) has evolved in recent years and is currently the preferred treatment worldwide. We analyzed the trends in the number of patients, number of aneurysms, aneurysm characteristics, and techniques used in a pure endovascular cohort of patients treated in a reference center. Materials and Methods: Between 2010 and 2020, a retrospective data collection of patients who underwent endovascular intervention of IAs was performed. We used the Mann-Kendal test to evaluate the trends. In addition, the moving-average technique was used to assess smoother curves. Results: Eight hundred and forty-five aneurysms were treated in 765 patients, the mean age was 53.9 ± 14.6 years and 81% were women. The number of patients (P = 0.016) and aneurysms (P = 0.003) increased significantly. Unruptured (P = 0.029) and posterior communicating artery aneurysms increased their frequency of treatment (P = 0.042). Balloon remodeling (P = 0.01) and the use of flow diverters showed a positive trend (P = 0.016). Conclusion: There have been an increased number of patients and aneurysms treated endovascularly at our institution, including unruptured and posterior communicating aneurysms. Advanced endovascular techniques also increased. Comparative studies including surgical cases must be done in our region to determine the best approach.

A simple but effective solution for proximal mark absence on some microcatheters in intracranial aneurysm embolization: Technical note.

Background: Endovascular coil embolization is increasingly being used for the treatment of intracranial aneurysms and other pathologies such as arteriovenous (AV) malformations and AV fistulas. Appropriate embolization technique requires a microcatheter with two radiopaque marks, one proximal and one distal. We present an alternative coils deployment technique for intracranial aneurysms, using a microcatheter without a proximal radiopaque mark. Methods: We describe the technique for embolization that was used in a 36-year-old female patient, in which we used a microcatheter without a proximal radiopaque mark for coil embolization of an intracranial aneurysm. Results: We used a Headway Duo flow directed microcatheter for a coiling embolization of an intracranial aneurysm, solving the absence of the proximal radiopaque mark by cannulating the microcatheter with a Traxcess 0.014 microguidewire, and placing an external mark on the screen in the proximal portion of the microguidewire 30 mm radiopaque tip to indirectly mark the proximal mark of the microcatheter. Conclusion: There is scarce evidence supporting the use of microcatheters with no proximal radiopaque mark for coil embolization. This report attempts to disclose how an easy and simple technique can be used as a rescue method to solve the proximal radiopaque mark absence during endovascular coil release procedures. To the best of our knowledge, this technique has not been previously described; therefore, its use is not widespread among neurointerventionists.

Long-term outcomes of ruptured saccular intracranial aneurysm clipping versus coiling: systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Previous meta-analyses comparing microsurgery and coiling that include BRAT may be inaccurate to compare the outcomes of ruptured saccular aneurysms. This study aims to evaluate 10-year efficiency, safety, and advantages of coiling compared with clipping in patients with spontaneous saccular aneurismal SAH as a primary outcome. Also analyzed secondary outcomes: no-occlusion, mortality, rebleeding, and retreatment. METHODS: A systematic search of the literature on microsurgical clipping versus coiling was done to identify RCTs with at least 10 years of follow-up published between 2000 and 2021. The primary outcome was favorable functional outcome, defined as a modified Rankin scale (mRS) score ≤ 2. Secondary outcomes were no-occlusion, mortality, rebleeding, and retreatment. Quality of the included trials was analyzed using the Risk of Bias 2.0 (RoB 2.0) tool. A random-effects meta-analysis was performed. RESULTS: Two studies reported 10-year follow-up results, and the meta-analysis did not demonstrate significant differences between groups (OR 0.9, 95%CI 0.66-1.24, I2 = 21%). No differences were observed compared clipping and coiling regarding occlusion rates (OR 5.3, 95%CI 0.8-36.3, I2 = 89%). Mortality rates did not show significant differences between treatment modalities (OR 0.97, 95%CI 0.77-1.21, I2 = 0%). Rebleeding rates were also similar between groups (OR 1.63, 95%CI 0.25-10.7, I2 = 37%); however, significantly higher retreatment rates were associated with coiling (OR 10.6, 95%CI 2.1-52.5, I2 = 80%). Overall, risk of bias was low. CONCLUSION: There are no long-term differences regarding no-occlusion, mortality, and rebleeding rates between coiling and clipping. Higher retreatment rates were associated with coiling.

Tips and Tricks in Microsurgical Treatment for Previously Embolized Aneurysms-Three-Dimensional Video.

One of the most popular treatment strategies for complex cerebral aneurysms with wide necks is stent-assisted coiling.1 Although it is a minimally invasive technique, it is associated with higher recurrence rates (approximately 20%) compared with surgical clipping.2 Recanalization is more common principally in ruptured aneurysms as well as in giant aneurysms, aneurysms located in the posterior circulation, aneurysms with a relatively wide neck morphology, and aneurysms followed for >1 year.2-6 Tirakotai et al. classified the indications for surgical treatment after coiling into 3 groups: 1) surgery of incompletely coiled aneurysms; 2) surgery for mass effects on neural structures; 3) surgery for vascular complications.7 Recanalization, if significant, often requires retreatment. Retreating with additional coils fails in perhaps 50% of cases.3 On the other hand, surgical clipping is complicated and difficult to perform. Recanalized aneurysms are categorized into 3 types: type I, coils are compressed; type II, coils are migrated; type III, coils are migrated, and multiple coils fill its neck or the parent artery. Direct clipping can be applied to types I and II, whereas trapping, wrapping, or auxiliary revascularization is required in type III.2 Coil extraction should not be attempted regularly because it is associated with high morbidity.8 In this three-dimensional video, we present the microsurgical treatment of a type I recanalized anterior communicating artery aneurysm, which in serial digital subtraction angiography control scans showed residual patency, progressive growth, and changes in its hemodynamic behavior (Video).

Reproduction in the bushmaster (Lachesis muta): uterine muscular coiling and female sperm storage

Prolonged sperm storage in the female reproductive tract is a widespread strategy among vertebrates. In reptiles, especially lizards and snakes, females have specialized structures to store sperm in their oviduct, which occur in the posterior infundibulum and the nonglandular uterus. Many viperids exhibit uterine muscular coiling (UMC) in the nonglandular uterus, and this modification has been proposed as an ancestral trait in this taxon to store sperm. However, UMC and oviductal sperm storage have not been reported in Lachesis. Here, we studied the reproductive tract of L. muta females using histological techniques and describe, for the first time, the occurrence of oviductal sperm storage and UMC in nonglandular uterus of this species. We also describe an increase in secretory activity in the oviduct throughout the reproductive cycle. Our results support the hypothesis that UMC is an ancestral character in Viperidae and suggest that female L. muta must store sperm in the oviduct to fertilize the oocytes. We also propose new hypotheses for reproductive strategies of L. muta in nature.

Symptomatic internal carotid artery dissection and kinking in a patient with fibromuscular dysplasia.

Isolated dissection of the internal carotid artery (ICA) is rare in young patients and is a cause for strong suspicion of fibromuscular dysplasia (FMD), especially when associated with artery elongation and tortuosity. The natural history of cerebrovascular FMD is unknown and management of symptomatic patients can be challenging. We report the case of a 44-year-old female patient with a history of transient ischemic attack in the absence of cardiovascular risk factors, associated with an isolated left ICA dissection and kinking. Carotid duplex ultrasound confirmed the diagnosis of dissection and demonstrated severe stenosis of the left ICA. The patient underwent surgical repair and histopathological evaluation confirmed the diagnosis of FMD with dissection. An autogenous great saphenous vein bypass was performed and the patient had an uneventful recovery. Cervical carotid artery dissection can be related to underlying arterial pathologies such as FMD, and the presence of ICA tortuosity highlights certain peculiarities for optimal management, which might be surgical.

A dissecção isolada da artéria carótida interna em pacientes jovens é rara, e a displasia fibromuscular deve ser altamente suspeitada principalmente quando estiver associada a alongamento e tortuosidade da artéria. A história natural da displasia fibromuscular cerebrovascular é desconhecida, e o manejo de pacientes sintomáticos pode ser desafiador. Apresentamos o caso de uma paciente de 44 anos com histórico de ataque isquêmico transitório sem fatores de risco cardiovasculares, associado a dissecção e acotovelamento isolados da artéria carótida interna esquerda. O ultrassom duplo das carótidas confirmou o diagnóstico de dissecção e demonstrou estenose grave na artéria carótida interna esquerda. A paciente foi submetida a reparo cirúrgico, e a avaliação histopatológica confirmou o diagnóstico de displasia fibromuscular com dissecção. Foi realizada cirurgia de ressecção do segmento e reconstrução com veia safena magna autógena, e a paciente se recuperou sem complicações. A dissecção da artéria carótida cervical pode estar relacionada a doenças arteriais subjacentes, como a displasia fibromuscular, e a presença da tortuosidade da artéria carótida interna destaca algumas particularidades no manejo ideal, o qual pode ser cirúrgico.

Stent-Induced Vascular Remodeling in Two-Step Stent-Assisted Coiling Treatment of Brain Aneurysms: A Closer Look Into the Hemodynamic Changes During the Stent Healing Period.

Stenting has become an important adjunctive tool for assisting coil embolization in complex-shaped intracranial aneurysms. However, as a secondary effect, stent deployment has been related to both immediate and delayed remodeling of the local vasculature. Recent studies have demonstrated that this phenomenon may assume different roles depending on the treatment stage. However, the extent of such event on the intra-aneurysmal hemodynamics is still unclear; especially when performing two-step stent-assisted coiling (SAC). Therefore, we performed computational fluid dynamics (CFD) analysis of the blood flow in four bifurcation aneurysms focusing on the stent healing period found in SAC as a two-step maneuver. Our results show that by changing the local vasculature, the intra-aneurysmal hemodynamics changes considerably. However, even though changes do occur, they were not consistent among the cases. Furthermore, by changing the local vasculature not only the shear levels change but also the shear distribution on the aneurysm surface. Additionally, a geometric analysis alone can mislead the estimation of the novel hemodynamic environment after vascular remodeling, especially in the presence of mixing streams. Therefore, although the novel local vasculature might induce an improved hemodynamic environment, it is also plausible to expect that adverse hemodynamic conditions might occur. This could pose a particularly delicate condition since the aneurysm surface remains completely exposed to the novel hemodynamic environment during the stent healing period. Finally, our study emphasizes that vascular remodeling should be considered when assessing the hemodynamics in aneurysms treated with stents, especially when evaluating the earlier stages of the treatment process.

Symptomatic internal carotid artery dissection and kinking in a patient with fibromuscular dysplasia / Dissecção e acotovelamento sintomáticos da artéria carótida interna em paciente com displasia fibromuscular

Abstract Isolated dissection of the internal carotid artery (ICA) is rare in young patients and is a cause for strong suspicion of fibromuscular dysplasia (FMD), especially when associated with artery elongation and tortuosity. The natural history of cerebrovascular FMD is unknown and management of symptomatic patients can be challenging. We report the case of a 44-year-old female patient with a history of transient ischemic attack in the absence of cardiovascular risk factors, associated with an isolated left ICA dissection and kinking. Carotid duplex ultrasound confirmed the diagnosis of dissection and demonstrated severe stenosis of the left ICA. The patient underwent surgical repair and histopathological evaluation confirmed the diagnosis of FMD with dissection. An autogenous great saphenous vein bypass was performed and the patient had an uneventful recovery. Cervical carotid artery dissection can be related to underlying arterial pathologies such as FMD, and the presence of ICA tortuosity highlights certain peculiarities for optimal management, which might be surgical.

Resumo A dissecção isolada da artéria carótida interna em pacientes jovens é rara, e a displasia fibromuscular deve ser altamente suspeitada principalmente quando estiver associada a alongamento e tortuosidade da artéria. A história natural da displasia fibromuscular cerebrovascular é desconhecida, e o manejo de pacientes sintomáticos pode ser desafiador. Apresentamos o caso de uma paciente de 44 anos com histórico de ataque isquêmico transitório sem fatores de risco cardiovasculares, associado a dissecção e acotovelamento isolados da artéria carótida interna esquerda. O ultrassom duplo das carótidas confirmou o diagnóstico de dissecção e demonstrou estenose grave na artéria carótida interna esquerda. A paciente foi submetida a reparo cirúrgico, e a avaliação histopatológica confirmou o diagnóstico de displasia fibromuscular com dissecção. Foi realizada cirurgia de ressecção do segmento e reconstrução com veia safena magna autógena, e a paciente se recuperou sem complicações. A dissecção da artéria carótida cervical pode estar relacionada a doenças arteriais subjacentes, como a displasia fibromuscular, e a presença da tortuosidade da artéria carótida interna destaca algumas particularidades no manejo ideal, o qual pode ser cirúrgico.

Coiling as a Rescue Strategy for Flow Diverter Prolapse into a Giant Intracranial Aneurysm.

BACKGROUND: Up to 3.2% of the adult population has an unruptured intracranial aneurysm (IA). Flow diversion is a relatively new treatment technique that is especially useful for large and morphologically unfavorable IAs. METHODS: A previously healthy woman aged 32 years presented with a 6-month history of ptosis and ophthalmoplegia of the left eye. A magnetic resonance imaging scan revealed a giant left internal carotid artery aneurysm. She was admitted for treatment using flow diversion. After delivery of the flow diverter (FD), prolapse of the proximal end of the stent into the aneurysmal sac was observed. FD stabilization was achieved by deploying multiple coils through a previously placed microcatheter to push the prolapsed end away from the aneurysmal lumen. RESULTS: The patient had a favorable outcome, with reduction of preoperative mass effect symptoms and complete obliteration of the aneurysm persisting at the 3-month follow-up. CONCLUSIONS: Giant IAs remain one of the most daunting clinical problems to treat. FD displacement is a rare (0.5%-0.75%) and possibly fatal complication. Currently, no clinical guidelines exist for its management. Adjunctive coiling is a possible rescue strategy for stabilizing an FD that foreshortened and prolapsed into the aneurysmal sac. Further studies are needed to identify the best approach to this complication.

Trends for in-hospital metrics in the treatment of intracranial aneurysms in Minas Gerais, Brazil.

Background: Aneurysmal subarachnoid hemorrhage (ASAH) and unruptured aneurysm (URA) are particularly important because of the high mortality rates, and physical and cognitive impairment, which affect the economically active population. The present work aims at describing the scenario regarding in-hospital indicators related to the following therapeutic approaches: vascular microsurgery (VMS) and endovascular therapy (EVT) in the state of Minas Gerais, Brazil, in order to gather information to construct hypotheses and plan actions. Methods: The study has an ecological design and it is also analytical for the time trends of 2008-2014. Trends for VMS and EVT therapies and mortality are estimated using linear regression, followed by the Prais-Winsten procedure. Data were obtained through Hospital Information System (Sistema de Informações Hospitalares - SIH) of Brazilian Public Health System (Sistema Único de Saúde - SUS). Results: In 2014, 601 procedures were performed, and out of these, 373 (62%) were triggered by SAH and 228 (38%) by URA. The frequency of procedures performed in males and in females results in a ratio of 1:2 for SAH procedures and 1:3 for URA procedures. A heterogeneous distribution of therapeutic approaches was seen among the hospital studied, suggesting a technological preference, which determines the therapeutic approach. Conclusion: Technological bias was observed for aneurysm treatment in Minas Gerais's hospitals. EVT is seen to have a growing trend to detriment of VMS (ß1 = 0.024; p = 0.025), with a stable mortality for both therapeutics in both pathologies (SAH and URA). EVT has been associated with a shorter hospital stay, with higher expenses for both ASAH and URA treatment. EVT showed an inverse correlation with in-hospital fatality for ASAH treatment.

The "Brain Stress Timing" phenomenon and other misinterpretations of randomized clinical trial on aneurysmal subarachnoid hemorrhage.

Clipping and coiling are currently the two alternatives in treatment of ruptured cerebral aneurysms. In spite of some meritorious analysis, further discussion is helpful to understand the actual state of art. Retreatment and rebleeding rates clearly favors clipping, although short-term functional outcome seems to be beneficial for clipping, while this different is not such if we perform the comparison at a longer follow up. Long-term follow ups and cost analysis are mandatory to have a clear view of the current picture in treatment of subarachnoid hemorrhage. Treatment strategy should be made by a multi-disciplinary team in accredited centers with proficient experience in both techniques.

Rupture of Persistent Primitive Trigeminal Artery-basilar Artery Aneurysm Managed with Stent-assisted Coiling.

Persistent primitive trigeminal artery (PPTA), a fetal carotid-basilar anastomosis, is the most common embryological vascular remnant persisting into adult age. However, reported cases associated with cerebral aneurysms are rare. A 33-year-old female presented with an extremely rare PPTA-basilar artery (PPTA-BA) aneurysm manifesting as subarachnoid hemorrhage. Computed tomography revealed subarachnoid bleeding in the prepontine cistern, and cerebral angiography disclosed a PPTA-BA aneurysm. The aneurysm was managed with stent-assisted coiling technique to achieve complete obliteration. The patient was discharged without neurological deficits 2 weeks later. At 6 months follow-up, the patient is doing well and has returned to her previous daily activities. PPTA-BA aneurysms usually present with cranial nerve palsy and sometimes with carotid-cavernous fistulae if they rupture. Their deep seating favors interventional management as a first option and this case illustrates the efficacy and safety of endovascular treatment. This case adds to the evidence that endovascular techniques are a safe and effective tool in managing aneurysms of the primitive trigeminal artery. Even in cases where the anastomosis itself is not preserved, the patient can be managed satisfactorily, provided that the patency of the basilar and the carotid artery are kept, like in our patient.

Preliminary Experience with the TransForm Occlusion Balloon Catheter: Safety and Potential Advantages.

PURPOSE: Balloon-assisted coiling (BAC) has made the treatment of aneurysms with complex shape and broad neck possible, especially during the acute phase of hemorrhage. The authors present a prospective series of their preliminary experience with the TransForm occlusion balloon catheter (TOBC). METHODS: Between September 2015 to February 2016 a total of 20 patients underwent endovascular treatment assisted by TOBC of which 19 had 20 untreated aneurysms and 1 patient harboring a meningioma was submitted to balloon test occlusion (BTO). The TOBC was used to perform BAC and BTO for the treatment of vasospasms and to cross the neck of giant aneurysms (anchor technique). All data regarding the feasibility and safety of treatment with the device were collected prospectively. RESULTS: All patients completed treatment according to the modality previously chosen. The balloon was employed solely for remodeling in 17 patients, for anchor technique in 2, for both remodeling and vasospasm angioplasty in 1 and for BTO in 1 patient. The balloon could be navigated to the target aneurysm in all cases. Evaluation of postoperative anatomical results indicated total occlusion in 13 (72.2 %) aneurysms, neck remnants in 4 (22.2 %) and residual sac filling in 1 (5.5 %). There were two (9.5 %) complications related to treatment, all thromboembolic. No technical complications were observed. CONCLUSION: The TOBC was shown to be safe and effective for the treatment of intracranial aneurysms with BAC. In addition, it was successfully employed to perform angioplasty for vasospasm and BTO. Finally, it was used in the balloon anchor technique for the first time.

Sandsitermes gen. nov., a new nasute termite genus from South America (Isoptera, Termitidae, Nasutitermitinae).

We establish herein a new genus of Neotropical termites of the subfamily Nasutitermitinae, Sandsitermes gen. nov.. The new genus accommodates a previously described species, Nasutitermes robustus (Holmgren), and is diagnosed by worker characters, including the mandibles, the gut-coiling configuration in situ, and the pattern of cushions and spines of the enteric valve. We characterized and illustrated the imago for the first time and redescribe the soldier and worker castes of Sandsitermes robustus gen. et comb. nov. from syntypes and other samples from eastern Peru. We support our taxonomic decision, presenting morphological differences between the gut pattern and enteric valve of S. robustus and 13 neotropical Nasutitermes species studied for this report, and discuss possible relationships with other neotropical nasute termites.

Impact of Coil Packing Density and Coiling Technique on Occlusion Rates for Aneurysms Treated with Stent-Assisted Coil Embolization.

BACKGROUND AND OBJECTIVE: Stent-assisted coil embolization is an established endovascular technique for wide-necked intracranial aneurysms. Although recanalization after coil embolization is reduced with the use of a stent, the impact of aneurysm packing density is less clear in stent-coiled aneurysms. The purpose of the present study was to assess packing density in stent-coiled aneurysms and evaluate its effect on recanalization and retreatment. METHODS: A retrospective analysis of consecutive aneurysms treated with stent-assisted coiling was performed at 2 academic institutions between 2007 and 2015. Aneurysm occlusion was assessed using digital subtraction angiography. Packing density was calculated using the AngioCalc app. RESULTS: Two hundred fifty-three aneurysms were identified (median age, 59 years). The median packing density was 35.3%. At last follow-up, 72.7% of aneurysms were completely obliterated and 19.4% had a neck remnant. Complete occlusion was associated with smaller aneurysms and coiling through stent interstices. A higher packing density was associated with increased rate of complete occlusion when analyzed as continuous variable. After adjustment for confounding variables, packing density was no longer predictive of complete occlusion (odds ratio = 1.018, P = 0.122). Similarly, there was no significant association between aneurysm occlusion, retreatment, and packing density when assessed by categories of high (>22%), moderate (12%-22%), and low (<12%) packing density. CONCLUSIONS: Aneurysm size remains the most important predictor of aneurysm recanalization and retreatment after stent-assisted coiling. Although higher packing densities were associated with increased rates of aneurysm occlusion in unadjusted statistical comparisons, this finding was no longer significant after adjusting for confounders.

[Endovascular coiling of a «true¼ posterior communicating artery aneurysm]. / Tratamiento endovascular de un aneurisma «verdadero¼ de la arteria comunicante posterior.

True posterior communicating artery aneurysms originate exclusively from the wall of this artery and should be differentiated from aneurysms of the posterior communicating segment of the distal carotid artery. As these lesions are rare, their anatomical relationships have been poorly described; likewise, reports concerning their endovascular treatment are extremely rare and the technical aspects poorly detailed. A case of a patient with a true aneurysm of the left posterior communicating artery treated by endovascular coiling is presented. A literature review was also conducted to illustrate the anatomical and technical details relevant to achieving its successful treatment.

A new genus and species of termites (Isoptera, Termitidae, Nasutitermitinae) from the rainforest of northern Peru.

A new genus and species of nasutitermitine termites are described and illustrated, based on soldier and worker characters. Sinqasapatermesgen. n., can be distinguished from all other nasutitermitine genera by its singular worker gut coiling and enteric valve characters: distal margin of the enteric valve not everted into the paunch but bending towards the ileum, that is, directed against the flow of food; enteric valve armature with one ring of six equal subtriangularly-shaped ridges, each ridge with short spines on the entire surface; enteric valve armature situatedonexternal face of cone, facing the internal ileum wall; enteric valve seating tri-lobed and separated from remaining portionof the paunch; paunch subdivided. Sinqasapatermes sachaesp. n., was collected on a tree in a very narrow flattened tunnel that was well concealed beneath lichens in a northern Peru rainforest (Arcadia, Loreto Province).