Mirto Nelso Prandini

Comparison between posterior lumbar fusion with pedicle screws and posterior lumbar interbody fusion with pedicle screws in adult spondylolisthesis

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.

Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti's syndrome

OBJECTIVE Bertolottis syndrome is a spine disorder characterized by the occurrence of a congenital lumbar transverse mega-apophysis in a transitional vertebral body that usually articulates with the sacrum or the iliac bone. It has been considered a possible cause of low back pain. METHOD We analyzed the cases of Bertolottis syndrome that failed clinical treatment and reviewed the literature concerning this subject. RESULTS Five patients in our series had severe low back pain due to the neo-articulation and two of them were successfully submitted to surgical resection of the transverse mega-apophysis. Taking into account the clinical and surgical experience acquired with these cases, we propose a diagnostic-therapeutic algorithm. CONCLUSION There is still no consensus about the most appropriate therapy for Bertolottis syndrome. In patients in whom the mega-apophysis itself may be the source of back pain, surgical resection may be a safe and effective procedure.OBJETIVO: A sindrome de Bertolotti e uma desordem congenita da coluna vertebral caracterizada pela ocorrencia de uma mega-apofise transversa lombar em uma vertebra de aspecto transicional, que geralmente se articula com o sacro ou com o osso iliaco. Tal sindrome tem sido considerada possivel causa de dor lombar. METODO: Analise dos casos de sindrome de Bertolotti que apresentavam dor lombar sem melhora com tratamento conservador e revisao dos artigos publicados. RESULTADOS: Foram revisados cinco pacientes que nao apresentaram melhora com o tratamento clinico, sendo que dois foram submetidos a resseccao cirurgica da mega-apofise transversa. Considerando a experiencia adquirida com estes casos, os autores propoem um algoritmo para diagnostico e tratamento da Sindrome de Bertolotti. CONCLUSAO: Ainda nao ha consenso sobre qual e a terapia mais apropriada para a Sindrome de Bertolotti. Em pacientes em que a mega-apofise parece ser a origem da lombalgia, a resseccao cirurgica parece ser um procedimento seguro e efetivo.

Chordoid meningioma: report of two cases

We present CT scan, MRI and histopathologic findings of two patients harboring a rare type of meningioma. In the first case, a 52 year-old male patient, a large parasellar mass invading the cavernous sinus, infiltrating the infratemporal fossa and extending as low as C2 was founded. The tumor was isointense on T1, enhanced strongly with gadolinium injection, and was hyperintense on T2. In the second case, a 19-year-old male patient, a large high density temporal right mass was disclosed by CT scan. Both patients were taken to surgery. In the first case, only a partial removal was possible to be accomplished due to a severe intra operative bleeding. In the second case, the tumor was totally removed. Both showed characteristic pathologic findings of a meningioma resembling a chordoma. Meningioma is a relatively common intracranial tumor, occurring most frequently in adults, showing a wide variety of growth patterns. We described a pattern that had a peculiar chordoma-like appearance. The pathological findings and the differential diagnosis from chordoma are discussed.

Malignant transformation of pleomorphic xanthoastrocytoma: case report

We report a case of a pleomorphic xantoastrocytoma which manifested itself as a cystic isodense lesion in the right fronto-temporal lobe in a 26 year-old woman. It appeared as a soft yellow tumor with cystic cavities on surgery. Five months after this surgery, the patient was submitted to a new operation, which revealed a friable tumor, easily differentiated from the normal parenchyma, with cystic components. The histopathological examination demonstrated pleomorphic xanthoastrocytoma with malignant transformation. Histologically, the tumor at first procedure was composed of pleomorphic astrocytes with multinucleated and foamy cells. A rare case of malignant transformation in pleomorphic xanthoastrocytoma is presented, discussed and illustrated in this paper.

Mild hypothermia reduces polymorphonuclear leukocytes infiltration in induced brain inflammation

Over the last 50 years deep hypothermia (23 degrees C) has demonstrated to be an excellent neuroprotective agent in cerebral ischemic injury. Mild hypothermia (31-33 degrees C) has proven to have the same neuroprotective properties without the detrimental effects of deep hypothermia. Mechanisms of injury that are exaggerated by moderate hyperthermia and ameliorated by hypothermia include, reduction of oxygen radical production, with peroxidase damage to lipids, proteins and DNA, microglial activation and ischemic depolarization, decrease in cerebral metabolic demand for oxygen and reduction of glycerin and excitatory amino acid (EAA) release. Studies have demonstrated that inflammation potentiates cerebral ischemic injury and that hypothermia can reduce neutrophil infiltration in ischemic regions. To further elucidate the mechanisms by which mild hypothermia produces neuroprotection in ischemia by attenuating the inflammatory response, we provoked inflammatory reaction, in brains of rats, dropping a substance that provokes a heavy inflammatory reaction. Two groups of ten animals underwent the same surgical procedure: the skull bone was partially removed, the duramater was opened and an inflammatory substance (5% carrageenin) was topically dropped. The scalp was sutured and, for the group that underwent neuroprotection, an ice bag was placed covering the entire skull surface, in order to maintain the brain temperature between 29.5-31 degrees C during 120 minutes. After three days the animals were sacrificed and their brains were examined. The group protected by hypothermia demonstrated a remarkable reduction of polymorphonuclear leukocytes (PMNL) infiltration, indicating that mild hypothermia can have neuroprotective effects by reducing the inflammatory reaction.

Cavernoma gigante: relato de dois casos

Cavernous angiomas or haemangiomas or yet cavernomas are malformations of the central nervous system classified as occult vascular brain lesions. These rare lesions are clinically silent. They are defined by the presence of abnormally large vascular cavities or sinusoids channels of variable size, with sharp walls, located inside but not invading the brain parenchyma. They can occur at any age, including the neonatal period. Most of the small lesions are located inside the brain parenchyma. No abnormal circulation can be demonstrated in angiography and CT scan can be helpful for diagnosis only in rare occasions. Magnetic resonance is the best exam to demonstrate the lesion. Despite the benign character some lesions may cause neurologic dysfunction when their removal may be difficult. Complete extirpation is the best treatment if the lesion is favorable located and is causing neurological dysfunction. Two cases of giant cavernomas with good outcome after total removal are present. Only three cases of giant cavernomas were reported in the literature.

Regional cooling for reducing brain temperature and intracranial pressure

OBJECTIVE To evaluate the effectiveness of regional cooling for reducing brain temperature (BrTe) and intracranial pressure (ICP) in patients where conventional clinical treatment has failed. METHOD Regional cooling was carried out using ice bags covering the area of the craniectomy (regional method) in 23 patients. The BrTe and ICP were determined using a fiber optic sensor. Thirteen patients (56.52%) were female. The ages ranged from 16 to 83 years (mean of 48.9). The mean APACHE II score was 25 points (11-35). The patients were submitted, on mean, to 61.7 hours (20-96) of regional cooling. RESULTS There was a significant reduction in mean BrTe (p<0.0001--from 37.1 degrees C to 35.2 degrees C) and mean ICP (p=0.0001--from 28 mmHg to 13 mmHg). CONCLUSION Our results suggest that mild brain hypothermia induced by regional cooling was effective in the control of ICP in patients who had previously undergone decompressive craniectomy.

Regional mild hypothermia in the protection of the ischemic brain

Objetivo: Demonstrar a protecao que a hipotermia moderada pode fornecer em casos de isquemia em encefalos de coelhos. Metodos: Foi utilizado um modelo de isquemia focal em coelhos, para avaliar a protecao fornecida por meio de hipotermia moderada, produzida atraves da colocacao de pedras de gelo contidas no interior de um pequeno saco plastico, em contato com o couro cabeludo de um hemicrânio onde a tabua ossea foi previamente removida. Vinte coelhos da raca Nova Zelândia Branca, pesando de 3,100 Kg a 3,750 Kg foram divididos em dois grupos: (A) um grupo controle onde foi produzida uma lesao isquemica por meio da coagulacao da arteria cerebral media e (B) um grupo submetido a neuroprotecao por hipotermia moderada regional durante 80 a 100 minutos apos a producao da mesma lesao isquemica. As seccoes de encefalos foram coradas com 2,3,5-Tryphenyltetrazolium (TTC). As lâminas foram fotografadas com câmara digital e o volume de infarto foi calculado atraves de um programa de computador. Resultados: O volume medio de infarto foi de 70,53 mm3 no grupo controle, enquanto que o grupo com neuroprotecao apresentou media de 41,30 mm3 em 5 animais. Cinco animais deste grupo nao demonstraram macroscopica e microscopicamente areas de infarto. Conclusoes: Concluimos que a hipotermia moderada, localmente aplicada, pode proteger encefalos isquemicos de coelhos.

Aggressive management of orbital meningeal melanocytoma

Summary¶Objective. Meningeal melanocytoma generally occurs in the posterior fossa. Orbital manifestation is rarely encountered. Methods. A thirty-five year-old man presented with progressive proptosis of his right eye. Computed tomography (CT) and Magnetic Resonance Imaging (MRI) of the brain showed an expansive intraconal mass lesion occupying the superior orbital compartment, the entire orbital apex, and the optic foramen. Histological analysis and Immunohistochical staining for S-100 and HMB-45 monoclonal antibodies confirmed melanocytoma. Findings. Microsurgical removal was accomplished through a fronto-orbital craniotomy. Chemotherapy and irradiation followed the initial intervention. The patient returned for follow up two years after surgery, complaining of headache and right visual loss. A subfrontal tumor with massive edema was found on follow up CT scan. Interpretation. Meningeal melanocytomas are rare benign pigmented tumors of the central nervous system. They are predominant in the posterior fossa and spinal cord and frequently mistaken for melanomas, especially on frozen sections. Orbital presentation is rare. The natural history is poorly defined.

Tratamento cirúrgico das fraturas do odontóide tipo II com parafuso anterior: análise de 15 casos

A retrospective analysis of the results of 15 patients with odontoid fractures type II P and II N, according to Roy-Camilles classification is presented. They were operated on by an anterior approach and direct fixation of the odontoid process through a screw. There were 13 men and 2 women, the age ranging from 14 to 74 years. The follow up period was from 6 to 36 months (mean 20 months). There was only one complication related to the surgical technique: one screw was misplaced and it was necessary another surgery to replace it. There were no deaths in this series. There were no screw breakdown and the fusion rate was 94%. We propose, based on this study, that the classification of Roy-Camille for odontoid fractures should be always used, since it proposes one surgical approach for each type of fracture. The results of this series show that this technique is useful and has advantages over another modalities of treatment. The correct diagnosis of the type of fracture and an appropriate selection of patients are the main elements to achieve good results.