Mircea Radu Gorgan

Step training in a rat model for complex aneurysmal vascular microsurgery

Abstract Introduction: Microsurgery training is a key step for the young neurosurgeons. Both in vascular and peripheral nerve pathology, microsurgical techniques are useful tools for the proper treatment. Many training models have been described, including ex vivo (chicken wings) and in vivo (rat, rabbit) ones. Complex microsurgery training include termino-terminal vessel anastomosis and nerve repair. The aim of this study was to describe a reproducible complex microsurgery training model in rats. Materials and methods: The experimental animals were Brown Norway male rats between 10-16 weeks (average 13) and weighing between 250-400g (average 320g). We performed n=10 rat hind limb replantations. The surgical steps and preoperative management are carefully described. We evaluated the vascular patency by clinical assessment-color, temperature, capillary refill. The rats were daily inspected for any signs of infections. The nerve regeneration was assessed by foot print method. Results: There were no case of vascular compromise or autophagia. All rats had long term survival (>90 days). The nerve regeneration was clinically completed at 6 months postoperative. The mean operative time was 183 minutes, and ischemia time was 25 minutes.

Finite Element Analysis of a Lumbar Vertebra Reconstructed by Biocomposite Alloplastic Grafts

This research approaches the fourth lumbar (L4) vertebra reconstruction by a tronconic alloplastic graft fabricated by a powder metallurgy technology using Ca5(PO4)3(OH) (hydroxyapatite), TiH2 (titanium hydride) and CaCO3 (calcium carbonate) particles as initial powder mixture. The high frequency of the L4 vertebra fractures due to motor vehicle traffic accidents justify the necessity of vertebral reconstruction. This approach simulates the biomechanical behavior of the ANSYS model consisting in the L4 vertebra and the tronconic biocomposite graft during the frontal impact load. The von Misses stress and strain responses from the model depend on the physical and mechanical properties of the biocomposite grafts, experimentally determined. The best simulated mechanical behavior corresponds to the mechanical shielding phenomenon occurring from the biocomposite graft on behalf of the L4 vertebra.

Preferential Association of Lissencephaly-1 Gene Expression with CD133+ Glioblastoma Cells

Lissencephaly-1 (Lis1) protein is a dynein-binding protein involved in neural stem cell division, morphogenesis and motility. To determine whether Lis1 is a key factor in glioblastoma, we evaluated its expression and function in CD133+ glioblastoma cells. Global, Lis1 gene expression is similar in glioblastoma and normal samples. Interestingly, immunohistochemistry data indicate increased Lis1 expression colocalized with CD133 in a subset of glioma cells, including the tumor cells with perivascular localization. Lis1 gene expression is increased up to 60-fold in CD133 positive cells isolated from primary cultures of glioblastoma and U87 glioblastoma cell line as compared to CD133 negative cells. To investigate the potential role of Lis1 in CD133+ glioblastoma cells, we silenced Lis1 gene in U87 cell line obtaining shLis1-U87 cells. In shLis1-U87 cell culture we noticed a significant decrease of CD133+ cells fraction as compared with control cells and also, CD133+ cells isolated from shLis1-U87 were two times less adhesive, migratory and proliferative, as compared with control transfected U87 CD133+ cells. Moreover, Lis1 silencing decreased the proliferative capacity of irradiated U87 cells, an effect attributable to the lower percentage of CD133+ cells. This is the first report showing a preferential expression of Lis1 gene in CD133+ glioblastoma cells. Our data suggest a role of Lis1 in regulating CD133+ glioblastoma cells function.

Experimental model of arteriovenous malformation in vitro using biological grafts

Abstract Introduction: Brain arteriovenous malformations (AVMs) represent a serious health problem all around the world. Experimental models help to better understand the pathophysiology of these lesions. Experiment: We performed an experimental model of AVM using biological grafts, arteries and veins harvested from chicken wings at the elbow joint. We used 14 vessels and we performed 20 end-to-end anastomoses to create a nidus with a single feeding artery and a single draining vein. The system was irrigated with colored solution. The experiment was done according with law in force regarding experimental research activity. Conclusions: Experimental models allow us to understand the hemodynamics and predict the outcome of brain AVMs in humans. This experimental model is a useful tool in understanding the hemodynamic properties of brain AVMs. It is very useful in vascular anastomosis training

Current perspectives concerning the multimodal therapy in Glioblastoma

Abstract GBM (Glioblastoma) is the most common, malignant type of primary brain tumor. It has a dismal prognosis, with an average life expectancy of less than 15 months. A better understanding of the tumor biology of GBM has been achieved in the past decade and set up new directions in the multimodal therapy by targeting the molecular paths involved in tumor initiation and progression. Invasion is a hallmark of GBM, and targeting the complex invasive mechanism of the tumor is mandatory in order to achieve a satisfactory result in GBM therapy. The goal of this review is to describe the tumor biology and key features of GBM and to provide an up-to-date overview of the current identified molecular alterations involved both in tumorigenesis and tumor progression.

Small and medium size intracranial aneurysms - a 5 years retrospective analysis trial and multimodal treatment

Abstract Clinical context. Subarachnoid hemorrhage (SAH) due to rupture of an aneurysm is one of the most common neurosurgical emergencies who account for onethird of stroke .In the SAH cases , aneurysms accounted for 70%. Aneurysms had a bleeding rate of 12 per 100,000 population per year, and in particular between 50 to 60 years of age with a high morbidity and mortality, especially in the first episode of bleeding at about 43% of cases (1, 4, 14). Surgery is indicated to prevent rebleeding. 2.5% of patients in the general population may have unbroken aneurysms with a prevalence of 0.65%, with a preponderance of aneurysms in a 2: 1 in women. ACI aneurysms are more common in women and Acom aneurysms are more common in men and in 15-30% of patients with presence of multiple aneurysms. Surgical timing, the assessment in each individual case for rebleeding usage of endovascular techniques (3, 12), neurological status, the presence or absence of intraparenchymal hematoma or intraventricular hemorrhage with or without vasospasm, have an influence on the result. Over a period of 5 years from January 2010 to November 2014, 317 cases of patients with intracranial aneurysms in four clinics of neurosurgery in Bagdasar -Arseni hospital have been studied. The follow up period range between 6 month and 4 years and 3 month.

Particular aspects of cerebral metastases secondary to malignant melanoma in comparison with other brain metastases

Abstract Authors present a retrospective study of 427 patients with brain metastases admitted and treated in third and fourth neurosurgical departments of Emergency Clinical Hospital “Bagdasar-Arseni” Bucharest, from January, 2005 until December, 2014. 62.1% of all patients were men and 37.9% were women, with a medium age of 56.8 years, ranging between 17 and 85 years. 311 patients (72.8%) had a single metastasis, 79 patients (18.5%) developed 2 or 3 metastases and 37 patients (8.7%) had more than 3 metastases. The biggest four metastases in multiple cases were noted in database regarding location, either reported to left / right hemisphere, either related to site (frontal parietal etc.), and dimensions. In the case of malignant melanoma (22 men and 24 women) the status of the primary tumor was noted: the malignant melanoma was operated in 32 cases (69.6%) and in 7 patients (15.2%) the primary tumor was not operated. In another 7 cases the status of the primary tumor was not noted. The most frequent location for malignant melanoma was the legs in women and anterior thorax in men. In conclusion, cerebral metastases from malignant melanoma have most frequent intratumoral hemorrhages, comparative with other primary sources. Common primary sites founded in this study is legs in women and anterior thorax in men. Treatment of cerebral metastases is complex, multimodal, implying neurosurgeons, oncologists and radiotherapists.

Radio-induced brain lesions

Abstract Introduction : Radiotherapy, an important tool in multimodal oncologic treatment, can cause radio-induced brain lesion development after a long period of time following irradiation. Material and method : We report 4 cases with radio-induced brain lesions, admitted into the Fourth Department of Neurosurgery, Emergency Clinical Hospital Bagdasar-Arseni, during a 4 years period of time. Results : Two patients had meningiomas and two had unruptured cavernomas. Other side effects of radiotherapy, such as diffuse brain atrophy, leukoencephalopathy, optic atrophy, panhypopituitarism were also noted. The two patients with large meningiomas underwent surgery, with good outcome. Observation was the choice for the two asymptomatic cavernomas. Panhypopituitarism needed synthetic hormonal replacement therapy. Conclusions : Radiotherapy can cause long-term complications and can induce development of new brain lesions into previous radiation area. Meningiomas and cavernomas can be radio-induced brain lesions. Meningiomas can grow to large size, requiring surgery. Unruptured asymptomatic cavernomas can be left in place and patients are followed clinical and with serial imaging. Other findings after radiotherapy are diffuse brain atrophy, leukoencephalopathy, optic atrophy and panhypopituitarism.