Next generation of ventricular catheters for hydrocephalus based on parametric design

Background The flow pattern of the cerebrospinal fluid is probably the most important factor related to obstruction of ventricular catheters during the normal treatment of hydro cephalus. To better comprehend the flow pattern, we have carried out a parametric study via numerical models of ven tricular catheters. In previous studies, the flow was studied under steady and, recently, in pulsatile boundary conditions by means of computational fluid dynamics (CFD) in three dimensional catheter models. Objective This study aimed to bring in prototype models of catheter CFD flow solutions as well to introduce the theory behind parametric development of ventricular catheters. Methods A preceding study allowed deriving basic principles which lead to designs with improved flow patterns of ventric ular catheters. The parameters chosen were the number of drainage segments, the distances between them, the number and diameter of the holes on each segment, as well as their relative angular position. Results CFD results of previously unreleased models of ven tricular catheter flow solutions are presented in this study. Parametric development guided new designs with better flow distribution while lowering the shear stress of the catheters holes. High-resolution 3D printed catheter solutions of three models and basic benchmark testing are introduced as well. Conclusions The next generation of catheter with homoge neous flow patterns based on parametric designs may repre sent a step forward for the treatment of hydrocephalus, by possibly broadening their lifespan

Controversies about Interspinous Process Devices in the Treatment of Degenerative Lumbar Spine Diseases: Past, Present, and Future

A large number of interspinous process devices (IPD) have been recently introduced to the lumbar spine market as an alternative to conventional decompressive surgery in managing symptomatic lumbar spinal pathology, especially in the older population. Despite the fact that they are composed of a wide range of different materials including titanium, polyetheretherketone, and elastomeric compounds, the aim of these devices is to unload spine, restoring foraminal height, and stabilize the spine by distracting the spinous processes. Although the initial reports represented the IPD as a safe, effective, and minimally invasive surgical alternative for relief of neurological symptoms in patients with low back degenerative diseases, recent studies have demonstrated less impressive clinical results and higher rate of failure than initially reported. The purpose of this paper is to provide a comprehensive overview on interspinous implants, their mechanisms of action, safety, cost, and effectiveness in the treatment of lumbar stenosis and degenerative disc diseases

Psychosocial and neurocognitive performance after spontaneous nonaneurysmal subarachnoid hemorrhage related to the APOE-epsilon4 genotype: a prospective 5-year follow-up study

OBJECT: In this study, the authors prospectively evaluated long-term psychosocial and neurocognitive performance in patients suffering from nonaneurysmal, nontraumatic subarachnoid hemorrhage (SAH) and investigated the association between the APOE-epsilon4 genotype and outcome in these patients. METHODS: All patients admitted to the authors' institution between January 2001 and January 2003 with spontaneous nonaneurysmal SAH were prospectively examined (mean follow-up 59.8 months). The APOE genotype was determined in all patients by polymerase chain reaction from a blood sample. Of the 30 patients included in this study, 11 were carriers of the epsilon4 allele. RESULTS: All patients showed a good recovery and regained full independence with no persisting neurological deficits. The patients with the epsilon4 allele, however, scored significantly higher on the Beck Depression Inventory (22.1 +/- 6.3 vs 14.1 +/- 5.1). At follow-up, depression was more persistent in the group with the epsilon4 allele compared with the group that lacked the allele. This finding reached statistical significance (p < 0.05). Selective attention was impaired in all patients during the first year of follow-up, with an earlier recovery noted in the patients without the epsilon4 allele. Moreover, there was a tendency toward a linear relationship between the Beck Depression Inventory and the d2 Test of Attention. Two patients who carried the epsilon4 allele did not return to their employment even after 5 years. CONCLUSIONS: The findings in this study suggest that the APOE genotypes may be associated with the psychosocial and neurocognitive performance after spontaneous nonaneurysmal SAH, even in the absence of neurological impairment. Physicians should consider patient genotype in assessing the long-term consequences of nonaneurysmal SAH

Surgical treatment of cerebellar metastases in elderly patients: A threshold that moves forward?

The impact of surgery for cerebellar brain metastases in elderly population has been the object of limited studies in literature. Given the increasing burden of their chronic illnesses, the decision to recommend surgery remains difficult.All patients aged ≥65 years, who underwent surgical resection of a cerebellar brain metastasis from May 2000 and May 2021 at IRCCS National Cancer Institute “Regina Elena”, were analyzed. The study cohort includes 48 patients with a mean age of 70.8 years. 7 patients belonged to the II Class according to the RPA classification, 41 to the III Class; the median GPA classification was 1.5. Median pre-operative and post-operative KPS was 60. Median Charlson Comorbidity Index (CCI) was 11; median 5-variable modified Frailty Index was 2. Overall, 14 patients (29%) presented perioperative neurologic and systemic complications. 34 patients (71%) were able to perform adjuvant therapies as RT and/or CHT after surgery. A higher CCI predicted complications occurrence (p = 0.044), while significant factors for a post-operative KPS ≥70, were i) hemispheric location of the metastasis, ii) higher pre-operative KPS, iii) RPA II classification. Median Overall Survival was 7 months. A post-operative KPS <70 (p = 0.004) and a short time interval between diagnosis of the primary tumor and cerebellar metastasis appearance, were predictive for a worse outcome (p = 0.012). Our study suggests that selected elderly patients with cerebellar metastases may benefit from microsurgery to continue their adjuvant therapies, although a high complications rate should be taken in account

Unruptured Aneurysms Italian Study (UAIS) background and method

Treatment of unruptured cerebral aneurysms still represents an unsettled question in neurosurgical and neuroradiological communities. Although nowadays the indication for treatment have become relatively clear, indeed uncertainity remains for what concerns the proper treatment modality (surgical or endovascular) in terms of both the risk and the mid and long-term efficacy of the two procedures. The "Unruptured Aneurysms Italian Study" is a cooperative prospective study which aims to delineate the "State of the Art" in a nation based population. It has been designed: 1) to depict the nationwide modality of treatment of Unruptured Aneurysms, 2) to assess in the most objective way the overall treatment-related mortality and morbidity as well as the surgical and endovascular risk in the respective patient populations (it is not a surgical versus endovascular study) and 3) to asses the efficacy of the different procedures in the mid and long term periods. The study started on June 2003 and to June 2006, 637 patients have been enrolled. The study will end when the 1000th patient is enrolled