Retreatment of previously treated intracranial aneurysm: Procedural complications and risk factors for complications.

OBJECTIVE: Intracranial aneurysm (IA) is a frequent vascular malformation that can be managed by endovascular treatment (EVT) or microsurgery. A previously treated IA can recanalize, which may require further treatment. The aim of our study was to evaluate procedural complications related to IA retreatment and their risk factors. METHODS: All patients retreated for IA between 2007 and 2017 in 4 hospitals were included. We retrospectively reviewed the frequency of procedural complications of IA retreatment, defined as death or≥1-point increase in modified Rankin score 24h after the procedure. We then screened for risk factors of procedural complications by comparing the characteristics of patients with and without complications. RESULTS: During the inclusion period, 4,997 IAs were treated in our 4 institutions. Of these, 237 (4.7%) were retreated. 29 (12.2%) had≥1 procedural complication. However, severe complications, defined as death or dependency at 1 month, occurred only in 3 patients (1.3%). The only risk factor for complications was microsurgical clipping as retreatment. CONCLUSIONS: Procedural complications during IA retreatment were frequent but, in most cases, retreatment did not lead to death or severe disability. The only risk factor for complications of IA retreatment was clipping as retreatment. However, the design of the study did not allow any conclusion to be drawn as to the optimal means of aneurysm retreatment, and further studies are needed.

An updated model of hydrocephalus in sheep to evaluate the performance of a device for ambulatory wireless monitoring of cerebral pressure through shunts.

BACKGROUND: Cerebrospinal fluid (CSF) diversion by shunts is the most common surgical treatment for hydrocephalus. Though effective, shunts are associated with risk of dysfunction leading to multiple surgical revisions, affecting patient quality-of-life and incurring high healthcare costs. There is a need for ambulatory monitoring systems for life-long assessment of shunt status. The present study aimed to develop a preclinical model assessing the feasibility of our wireless device for continuous monitoring of cerebral pressure in shunts. METHODS: We first adapted a previous hydrocephalus model in sheep, which used an intracisternal kaolin injection. Seven animals were used to establish the model, and 1 sheep with naturally dilated ventricles was used as control. Hydrocephalus was confirmed by clinical examination and brain imaging before inserting the ventriculoperitoneal shunts and the monitoring device allowing continuous measurement of the pressure through the shunt for a few days in 3 sheep. An external ventricular drain was used as gold standard. RESULTS: Our results showed that a reduction in kaolin dose associated to postoperative management was crucial to reduce morbidity and mortality rates in the model. Ventriculomegaly was confirmed by imaging 4 days after injection of 75mg kaolin into the cisterna magna. For the implanted sheep, recordings revealed high sensitivity of our sensor in detecting fluctuations in cerebral pressure compared to conventional measurements. CONCLUSIONS: This proof-of-concept study highlights the potential of this preclinical model for testing new shunt devices.

Impact of discontinuation of antithrombotic therapy after surgery for chronic subdural hematoma.

INTRODUCTION: The management of antithrombotic therapy (AT) after surgery for chronic subdural hematoma (cSDH) requires taking account of the balance of risk between hemorrhage recurrence (HR) and the prophylactic thromboembolic effect (TE). The goal of the present study was to evaluate the prevalence of vascular events (VE: TE and/or HR) in the first 3 postoperative months after cSDH evacuation in patients previously treated by AT. The impact of AT resumption was also evaluated. PATIENTS AND METHODS: This observational prospective multicenter collaborative study (14 French neurosurgery centers) included patients with cSDH treated by AT and operated on between May 2017 and March 2018. Data collection used an e-CRF, and was principally based on an admission questionnaire and outcome/progression at 3 months. RESULTS: In this cohort of 211 patients, VE occurred in 58 patients (27.5%): HR in 47 (22.3%), TE in 17 (8%), with mixed event in 6 cases (2%). Median overall time to onset of complications 26 days±31.5, and specifically 43.5 days±29.25 for HR. Non-resumption of AT significantly increased the relative risk of VE [OR: 4.14; 95% CI: 2.08 - 8.56; P <0.001] and especially of TE [OR: 7.5; 95% CI: 1.2 - 42; P<0.001]. The relative risk of HR was significantly increased when AT was resumed at less than 30 days (P=0.015). CONCLUSION: The occurrence of VE in patients operated on for cSDH and previously treated by AT was statistically significant (27.5%). HR was the most common event (22.3%), whereas TE accounted for only the 8%, although with shorter time to onset. In order to prevent TE risk, AT should be restarted after 30 days, as HR risk is greatly decreased beyond this time.

Entrapment of the basilar artery within a clivus fracture: Case report and literature review.

A review of the literature revealed that basilar artery (BA) entrapment is a very rare (17 cases published) and severe pathological condition, which often leads to death. We report the case of a 72-year-old man who presented with a longitudinal clivus fracture associated with a basilar artery entrapment. This entrapment was responsible for a basilar artery dissection, which led to an ischemic stroke in the pons. The patient was managed with medical treatment, mainly to avoid a progression towards an ischemic stroke. It consisted of heparin therapy followed by antiplatelet therapy, which finally resulted in a successful outcome. In BA entrapment most of the patients who had a favorable outcome received antithrombotic therapy. This suggests that antithrombotic therapy might be useful in the first line treatment of post-traumatic BA entrapment.

Breast cancer estrogen receptor assays: assessment of a direct hyperbolic fitting to analyse multipoint binding data.

Analysis of breast cancer estrogen receptor multipoint binding assay is performed by fitting experimental data to a hyperbolic model derived from the law of mass action. The calculations performed on a microcomputer are carried out from the total bound and free ligand concentrations. The parameters estimated by hyperbolic fitting, receptor concentration N and constant of dissociation K, well agree with those obtained by Scatchard's transformation. N and K derived from hyperbolic analysis are much less susceptible to the influence of experimental errors. The method is more reliable at low receptor concentrations. The main advantage of the hyperbolic fitting is to simplify the technical methodology in clinical laboratory practice; there is no need to determine the non-specific bindings experimentally. Calculations can be easily automated on any laboratory microcomputer. Assays of any kind of receptor could be analysed by the hyperbolic fitting when the physical-chemical equilibrium between receptor, nonsaturable component and ligand can be approximated by a two-component model.