237 ACoA aneurysms clipped or embolized. Outcomes measurement using the De Santis-CESE assessment tool

AIM: The aim of this retrospective study was to demonstrate the difference in patient outcomes after treatment for bleeding endocranial aneurysms when evaluated with methods based on different assessment criteria. METHODS: The outcome of 237 patients, 141 of which were operated on for anterior communicating artery aneurysm and 96 embolized, was assessed by a new method developed by De Santis. The patients operated on were assessed by the Glasgow Outcome Scale (GOS) and Rank Disability Scale (RDS) and the results of the latter were compared with the new method, the De Santis-CESE (Clinical Emotional Social Evaluation) method, which consists of a clinical evaluation and a numeric scoring system based on seven standard points. Comparison between the three methods showed significantly different outcomes. Patients who underwent surgical operation showed changes in character and behaviour, whereas the others showed cognitive, emotional and sexual habit changes. CONCLUSION: Compared with the GOS and RDS instruments, the CESE method showed significant differences in patient outcome assessment, particularly regarding best outcomes. These differences may be due to the greater sensitivity of the CESE method over the other two scales. Furthermore, surgical patients seemed to achieve a better outcome than endovascular patients. The authors intend to conduct a prospective study to test the results obtained in this retrospective study.     

Thrombotic thrombocytopenic purpura--then and now

Thrombotic thrombocytopenic purpura (TTP) is a potentially life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and formation of microthrombi in several organs. The disease may manifest once in a lifetime or may relapse after complete recovery of the initial episode; in these recurrent cases, death or neurological sequelae are common final outcomes. Accumulation of unusually large (UL) von Willebrand factor (VWF) multimers was described in the plasma of patients with TTP. Such ULVWF multimers are synthesized in endothelial cells and megakaryocytes and are secreted into the blood upon stimulation. However, in healthy individuals ULVWF multimers do not normally circulate because they are rapidly reduced into smaller multimers soon after their secretion due to cleavage by a plasma metalloprotease, ADAMTS13. Deficiency of ADAMTS13 has been reported consistently in patients with TTP. Such defect may be constitutive, due to homozygous or double heterozygous mutations in the corresponding gene, or acquired, due to the presence of circulating inhibitory antibodies. It follows that in TTP patients, the absent or severely depressed plasma ADAMTS13 activity limits the cleavage of ULVWF multimers, which remain anchored to the endothelial cells in long strings. Particularly under conditions of high shear stress, the multimers may promote the adhesion of circulating platelets, initiating thrombus formation. The clinical implications of these findings to the diagnosis and treatment of TTP are discussed.     

Cervical spine biomechanics following implantation of a disc prosthesis

This study presents a finite element model of the C4-C7 segment in healthy conditions and after implantation of a disc prosthesis at a single level, in order to investigate of the influence of disc arthroplasty on the biomechanics of the cervical spine. A nonlinear finite element model of the C4-C7 segment in intact conditions was developed and run in flexion and extension. A detailed model of the Bryan disc prosthesis, including contacts between the different components of the device, was built and positioned at C5-C6. The calculated segmental motion resulted preserved after disc arthroplasty, with respect to the model of the intact spine, in both flexion and extension. A general preservation of the forces transmitted through the facet joints was obtained; a minor force increase at the implanted level was detected. The analysis of the instantaneous centers of rotation (ICR) in flexion-extension showed the preservation of a physiological kinematics. The mechanical behaviour showed an asymmetry between flexion and extension, probably due to the removal of the anterior longitudinal ligament and the anterior part of the annulus fibrosus, and the preservation of the posterior structures. In general, the disc prosthesis showed to be able to reproduce a nearly physiological motion. However, other important mechanical aspects, such as the possible micromotion at the bone-implant interface and the possible degenerative conditions of the spine, need to be evaluated before drawing a conclusion about total disc arthroplasty from an engineering point of view.