Aristotelis P. Mitsos

The Haemodynamics of Endovascular Aneurysm Treatment: A Computational Modelling Approach for Estimating the Influence of Multiple Coil Deployment

This paper proposes a novel computational methodology for modelling the haemodynamic effects of endovascular coil embolization for cerebral aneurysms. We employ high-resolution 3-D angiographic data to reconstruct the intracranial geometry and we model the coiled part of the aneurysm as a porous medium, with porosity decreasing as coils are inserted. The actual dimensions of the coils employed are used to determine the characteristics of the porous medium. Simulation results for saccular aneurysms from the anterior communicating and middle cerebral arteries show that insertion of coils rapidly changes intraaneurysmal blood flow and causes reduction in mural pressure and blood velocity up to stagnation, providing favorable conditions for thrombus formation and obliteration of the aneurysm.

Delayed visual deficits and monocular blindness after endovascular treatment of large and giant paraophthalmic aneurysms.

OBJECTIVEParaophthalmic aneurysms may exert mass effect on the optic apparatus. Although surgical clipping and endovascular coiling of these aneurysms can be complicated by immediate postoperative visual deterioration, endovascular coil embolization has the unique risk of visual complications later (>24 h) in the perioperative period. METHODSSix patients with a delayed onset of vision loss after technically successful coil embolization of paraophthalmic region aneurysms were identified. All available clinical, angiographic, and cross sectional imaging for these patients, in addition to histopathological data, were reviewed. RESULTSSix patients who underwent endovascular treatment of paraclinoid aneurysms at our institutions developed delayed postoperative visual decline. Four were treated with combination hydrogel-coated and bare platinum coils, one with hydrogel-coated coils, and one with bare platinum coils. Three patients presented with some degree of visual impairment caused by their aneurysms. Catheter angiography performed after the visual decline revealed no etiology in any of the cases. Magnetic resonance imaging was performed in all patients and was unremarkable in two. At follow-up, two had improved, three remained unchanged, and one patient died before any follow-up assessment of her vision. CONCLUSIONBoth acute and delayed visual disturbances can present after the endovascular treatment of carotid artery paraophthalmic aneurysms. Delayed visual deterioration can be observed up to 35 days after embolization. Although the cause is still undefined, it is likely that the more delayed visual deterioration can be attributed to progression of mass effect and/or perianeurysmal inflammatory change. Our case series raises the possibility that this phenomenon may be more likely with HydroCoil (HydroCoil Embolic System; MicroVention, Aliso Viejo, CA). This possibility should be taken into account by neurointerventionists when selecting a coil type to treat large paraophthalmic aneurysms.

Late isolated brain metastasis following enucleation for choroidal melanoma.

Brain metastases from choroidal melanoma are rare and usually have a grave prognosis. A case of successfully treated late isolated brain metastasis from choroidal melanoma is described. A 35-year-old man presented with epileptic seizures of recent origin, 9 years following enucleation for choroidal melanoma. Imaging studies revealed a lesion of the right frontal lobe that was surgically removed. Results of pathologic examination were compatible with metastatic choroidal melanoma. The patient is asymptomatic 5 years postoperatively. Late isolated brain metastases from uveal melanoma may be treatable by local resection. Close, lifelong follow-up is required to diagnose and aggressively treat metastatic disease.

Intraparenchymal myxopapillary ependymoma: Case report

OBJECTIVE AND IMPORTANCE:Myxopapillary ependymoma is a histological variant of ependymoma found in the cauda equina region. The most characteristic histological feature of myxopapillary tumors is the abundance of intercellular and perivascular mucin and the arborizing vasculature, which tends to form papillae. Primary intracerebral myxopapillary ependymomas are extremely rare; only three cases have been reported in the previous literature. CLINICAL PRESENTATION:A 68-year-old man presented with disorientation and dizziness caused by a cystic left frontal intraparenchymal lesion. This proved to be a myxopapillary ependymoma. Similarities to previously reported cases are discussed, as are the findings on magnetic resonance imaging. There is also a literature review of the histological findings, natural history, and outcome of surgically treated myxopapillary ependymoma. INTERVENTION:The lesion was totally removed. After surgery, the patient was neurologically intact and had an uneventful recovery. CONCLUSION:This is the fourth reported case of histologically proven primary myxopapillary intracranial ependymoma.

Greece reports prototype intervention with first peripherally inserted central catheter: case report and literature review

Placement of peripherally inserted central catheters (PICCs), definitely offers a clear advantage over any other method regarding central venous catheterization. Its ultrasonographic orientation enhances significantly its accuracy, safety and efficacy, making this method extremely comfortable for the patient who can continue his or her therapy even in an outpatient basis. We present the first reported case of a PICCS insertion in Greece, which has been performed by a university-degree nurse. The aim of this review of literature was to present the evolution in nursing practice in Greece. A PICC was inserted in a 77-year-old male patient suffering from a recent chemical pneumonia with a history of Alzheimers disease. A description of all the technical details of this insertion is reported, focusing on the pros and cons of the method and a thorough review of the history and advances in central venous catheterization throughout the years is also presented. PICCs provide long-term intravenous access and facilitate the delivery of extended antibiotic therapy, chemotherapy and total parenteral nutrition. We strongly believe that PICCs are the safest and most effective method of peripherally inserted central venous catheterization. Larger series are necessary to prove the above hypothesis, and they are under construction by our team.

Neuron Specific Enolase (NSE): A Valuable Prognostic Factor of Central Nervous System Dysfunction Following Cardiac Surgery

Purpose: The aim of this study was to evaluate neuron specific enolase (NSE) as prognostic factor for CNS disorders developed in relation to cardiac surgery. Patients and methods: A cohort of 92 patients were divided into two groups; the experimental group consisted of patients undergoing openheart bypass surgery (50 patients) and the control group consisting of 42 patients undergoing general surgery procedures. The blood levels of NSE were measured in both groups before and 24 h after the operation and have been related to the incidence of the postoperative brain damage as well as to the duration of the extracorporeal circulation (ECC). Results: The analysis of our results showed that the changes of blood NSE levels, before and immediately after ECC in open-heart surgery have been related to the incidence of postoperative brain dysfunction according to a specific mathematical equation. This incidence was raised also in relation to the age of the patient and the duration of ECC. On the contrary, NSE seems to have no prognostic value in general surgery.

Solitary internal jugular vein invasion by thyroid carcinoma: resection and reconstruction

Thyroid carcinoma usually presents as asymptomatic thyroid nodule. Thyroid cancer may show microscopic vascular invasion; however, internal jugular vein (IJV) invasion is a rare complication of thyroid cancer. We present a case of unilateral invasion of IJV caused by local nodal recurrence of the primary thyroid carcinoma. The patient had undergone a near total thyroidectomy, followed by modified left lymph node resection with left IJV resection. In this case, the infiltrated part of the right IJV was resected, and the vessel was reconstructed using saphenous vein autograft. In locally advanced, well-differentiated thyroid cancers, only the radical resection relieves symptoms and increases survival.

Intraoperative Use of Cell Saver on Patients Undergoing Open Abdominal Aortic Aneurysm Surgical Repair: A Greek Hospital Experience

Perioperative use of a cell saver device can serve as a cost-beneficial alternative to the transfusion method, especially in countries where the cost of a single unit of blood is high. The purpose of this study, conducted in a Greek hospital, was to calculate the cost benefit of using a cell saver device to salvage intraoperative blood during open surgical abdominal aortic aneurysm repair or open aortofemoral bypass for occlusive disease. This retrospective study measured the amounts of salvaged blood and reinfused blood encountered during the procedure and then calculated the cost benefit of cell saver use. With the cost of a unit of blood purchased in Greece about €450 (

Endovascular Treatment of Cerebral Aneurysms in Relation to Their Parent Artery Wall: A Single Center Study

585), the blood units salvaged and reinfused were calculated at a mean cost benefit of €754 (

A randomized double-blind trial of anesthesia provided for colonoscopy by university-degreed anesthesia nurses in Greece: s afety and efficacy

980) per case.