Influence of resin cement and post configuration on bond strength to root dentine.

AIM: To evaluate the effect of luting agent and fibreglass post design on bond strength to root dentine at different depths within the canal. METHODOLOGY: Ninety single-rooted teeth were root filled and prepared to receive either a parallel-sided and serrated fibreglass post (Reforpost no. 2) or a tapered and smooth fibreglass post (Exato Cônico). The posts were cemented with the following resin cements: dual-cured resin cement (Rely X ARC), two self-adhesive resin cements (Rely X Unicem and MaxCem) and a self-cured resin cement (Cement-Post). The roots were cross-sectioned to obtain two 1-mm-thick discs for each cervical, middle and apical third of the prepared root portion. The posts were submitted to a micropush-out test at a speed of 0.5 mm min(-1), and the bond strength values (MPa) were submitted to anova in a split-plot arrangement and Tukey's test (P < 0.05). RESULTS: The RelyX Unicem demonstrated significantly higher bond strength values (P < 0.001) along the root dentine. The RelyX ARC and Cement-Post had similar bond strength values in the cervical third; however, the bond strength decreased significantly (P < 0.001) in an apical direction for the RelyX ARC. Significantly lower bond strength values (P < 0.001), irrespective of canal region, were found for MaxCem cement. The bond strength was similar for both post configurations irrespective of the resin cement and canal region. CONCLUSIONS: The retention of glass fibre posts remained unaffected by surface roughness but was influenced by resin cement type. The self-adhesive cement RelyX Unicem yielded a significantly greater (P < 0.001) bond strength value when cementing the fibreglass posts.

[Stereotactic-guided surgery for cavernous angiomas]. / Cirurgia estereotáxica guiada para angiomas cavernosos.

Intracerebral cavernous angiomas may cause hemorrhage, epileptic seizures and neurological deficits. The diagnosis of these lesions became easier with the advent of the magnetic resonance image (MRI). Radical resection is the treatment of choice. Due to frequent subcortical or deep location, image-guided techniques, such as stereotactic-guided surgery, offer many advantages as smaller skin incision and craniotomy, less brain manipulation with consequently lower morbidity. We present a series of nine cavernous angiomas treated by stereotactic-guided radical surgical resection. The diagnosis was done by MRI and confirmed by pathologic studies in all cases. Mean age of patients was 30 years old (range 20-54 years). Postoperative morbidity occurred in two cases: one patient had a convulsion on the third postoperative day and the other presented dysphasia and hemiparesis on the second postoperative day, both with total recovery. Total resection of the lesion was possible in all cases with no neurological deficit.

Saphenous vein graft bypass in the treatment of giant cavernous sinus aneurysms: report of two cases.

Two cases of giant intracavernous aneurysms treated by high flow bypass with saphenous vein graft between the external carotid artery (ECA) and branches of the middle cerebral artery (MCA) are presented. Very often these aneurysms are unclippable because they are fusiform or have a large neck. Occlusion of the internal carotid artery (ICA) is the treatment of choice in many cases. This procedure has however a high risk of brain infarction. Revascularization of the brain by extra-intracranial anastomosis between the superficial temporal artery (STA) and branches of the MCA is frequently performed. This procedure provides however a low flow bypass and brain infarction may occur. We report two cases of giant cavernous sinus aneurysms treated by high flow bypass and endovascular balloon occlusion of the ICA. Immediate high flow revascularization of MCA branches was achieved and the patients showed no ischemic events. Follow-up of 8 and 14 months after operation shows patency of the venous graft and no neurological deficits. Angiographic control examination showed complete aneurysm occlusion in both cases.

[Arteriovenous malformations of the central nervous system. Analysis of 53 cases]. / Malformações arteriovenosas do sistema nervoso central. Análise de 53 casos.

Fifty-three patients with arteriovenous malformation (AVM) were studied. The mean age at the time of diagnosis was 32.5 +/- 11.5 years (range 3 to 56 years); the sex ratio was male 1.9:1 female. The most common clinical presentation was intracranial hemorrhage, followed by focal neurological signs, headache, epilepsy, and acute deep coma. Fourty-three (82%) out of the total number of AVM were supratentorial and had the following distribution: 10 temporal lobe, 9 pariental lobe, 6 frontal lobe, 3 occipital lobe, 3 frontotemporal, 4 corpus callosum/pericalosal, 1 temporo-occipital, 1 temporoparieto-occipital, 6 deep-located (3 thalamic, 3 basal ganglia). Spetzler-Martin grade II was seen in 17 cases (32%), grade III in 21 cases (39%), and grade IV in 10 cases (19%). AVM-associated aneurysms were detected in 3 patients (5.6%). All three cases were middle artery aneurysms ipsilateral to AVM. Twelve (32%) out of 37 operated patients were submitted to embolization prior to surgery. AVM was totally removed in all cases except one. Embolization without posterior surgery was used in 11 patients; in 3 of them, embolization was partial. Two patients were neither embolized nor operated on. Three patients were, submitted to radiosurgery because they were poor candidates to embolization and/or surgery. Mortality rate was 1.8%. All patients returned to their normal life function after a period of recovery. Associated or isolated therapies should be individualized to each patient with AVM and is likely to provide results better than the expected outcome without any treatment.

[Stereotactic implantation of depth electrodes by magnetic resonance image in epilepsy surgery]. / Implantação estereotáxica de eletrodos profundos por ressonância magnética para cirurgia de epilepsia.

We present the case of a 40-year-old woman with refractory epilepsy since aged 18, who was submitted to video-EEG monitoring with intracerebral depth electrodes. The clinical history and examination, magnetic resonance image (MRI), video-EEG and neuropsychological study did not allow the determination of the cerebral onset of epileptic seizures. Depth electrodes inserted by MRI-guided stereotaxis allowed the recording of the epileptic activity and thus showed quite accurately the area of the brain to be surgically resected. She underwent a right anterior temporal lobectomy with amygdalohippocampectomy. The immediate postoperative period was uneventful and she is without epileptic seizures after three months of follow-up. The average pre-operative free-seizure period was two weeks. To our knowledge, this is the first stereotactic surgery for insertion of depth intracerebral electrodes in epilepsy in Brazil.

Maffucci's syndrome associated with a cranial base chondrosarcoma: case report and literature review.

OBJECTIVE AND IMPORTANCE: Our objective was to study the diagnosis and management of this rare condition. A review of the literature concerning chondrosarcomas related to Maffucci's syndrome is reported. Cause and management are discussed. CLINICAL PRESENTATION: We report a case of Maffucci's syndrome associated with a cranial base chondrosarcoma. To our knowledge, only five similar cases have been reported in the literature. The differential diagnosis between Ollier's disease and Maffucci's syndrome and the causes of these conditions are not clear. INTERVENTION: An 18-year-old female patient presented with a giant tumor involving the posterior fossa, clivus, middle fossa, and cavernous sinus. The lesion could be totally removed through a transzygomatic approach. The histological diagnosis was chondrosarcoma. It was confirmed by immunohistochemical studies. There were no postoperative complications. CONCLUSION: Maffucci's syndrome is a rare clinical condition that presents difficulties concerning its diagnosis and management. It is characterized by the presence of multiple enchondromas and cutaneous hemangiomas. Intracranial chondrosarcomas may be associated with this syndrome. Immunohistochemical studies are necessary to differentiate chondrosarcomas from chordomas. The treatment of choice for cranial base chondrosarcomas is total removal of the lesion. Total removal may be very difficult to achieve because of the involvement of neurovascular structures. Alternative therapies, such as proton beam radiosurgery, should be considered. In this case, radical removal of the tumor was possible using a transzygomatic approach. Gross total removal of large cranial base chondrosarcomas is possible, but a longer follow-up period is necessary to ascertain that radical resection was achieved.

Middle cerebral artery revascularization. Anatomical studies and considerations on the anastomosis site.

In the surgical management of skull base lesions and vascular diseases such as giant aneurysms, involvement of the internal carotid artery may require the resection or the occlusion of the vessel. The anastomosis of the external carotid artery and the middle cerebral artery with venous graft may be indicated to re-establish the blood flow. To determine the best suture site in the middle cerebral artery, an anatomical study was carried out. Fourteen cerebral hemispheres were analysed after the injection of red latex into the internal carotid artery. The superior and inferior trunk of the main division of the middle cerebral artery have more than 2 mm of diameter. They are superficial allowing an anastomosis using a venous graft. The superior trunk has a disadvantage, it gives rise to branches for the precentral and post-central giri. The anastomosis with the inferior trunk presents lower risk of neurological deficit even though the angular artery originates from it.

Acoustic neurinomas. Diagnosis and treatment.

We present our experience with 83 patients with acoustic neurinomas (January 1988 to November 1996); 81 patients underwent surgery and 2 patients with intracanalicular neurinomas received conservative therapy due to their advanced age (1 case) and patient's option (1 case). The surgical approach was retrosigmoid/transmeatal and the goal was total removal in one procedure with preservation of facial and cochlear nerves. Radical removal of lesion was attempted in 79 cases and it was possible in 77 patients. Subtotal tumor resection was planned in 2 cases. Facial nerve function (grades I to III, House and Brackman) was preserved in 90% and hearing in 58% of those with preoperative hearing. Three patients died due to postoperative complications. Early diagnosis of acoustic neurinomas is the most important factor in the prognosis and is one of the most important conquest of neurophysiology and modern neuroimaging. The management of these patients still present many controversial points. This article presents the diagnostic procedures used for acoustic neurinomas, the advantages and disadvantages of the different surgical approaches and the alternative management of these lesions.

[Surgical anatomy of the nasal transphenoidal approach for pituitary tumors]. / Anatomia cirúrgica do acesso nasal transesfenoidal para tumores da hipófise.

Different distances related to the nasal transphenoidal approach were measured on the hemiheads of eighteen cadavers in order to study its limits and advantages. The main mean measures obtained (mm) were: major diameter of the nostril 15.18: height of the nasal cavity 44.11, nostril-sella turcica distance 71.71. These results show that the nasal approach is wide and direct to the sella turcica. The present study demonstrate the possibility of preservation of the cartilaginous septum and other structures which are usually damaged when the sublabial approach is employed.

Comparison of MRI-guided and ventriculography-based stereotactic surgery for Parkinson's disease.

Stereotactic surgery for Parkinson's disease can be performed using different neuroimaging methods. Ventriculography has been used to locate the coordinates of the structures close to the third ventricle. Although it has several potential disadvantages related to the intraventricular injection of iodine contrast, it is considered a precise method. Computed tomography and magnetic resonance imaging have been used in some centers. In order to compare their efficacy, 50 stereotactic thalamotomies for Parkinson's disease were performed using either ventriculography (VE) (25) or magnetic resonance imaging (MRI) (25). In 14 out of 25 VE procedures, computed tomography (CT-scan) was also used and showed a significant mean difference of coordinate Y and Z. The clinical results employing either VE or MRI were similar, with 80% abolition of tremor in the VE group, and 84% in the MRI group, after a follow up period of at least 3 months. Another 12% of VE and 16% of MRI group showed significant improvement of tremor. Complication rate was 4% in both groups. MRI-guided stereotactic thalamotomy in Parkinson's disease has shown good clinical results, comparable to VE-guided stereotaxis.

[Stereotactic surgery for intracranial mass lesions: diagnosis and treatment]. / Cirurgia estereotáctica para processos expansivos intracranianos: diagnóstico e tratamento.

The authors present a study about 50 stereotactic procedures for intracranial lesions. In 12 cases stereotaxis was used as a treatment: stereotactic surgical resection (5 patients) and aspiration of lesions (7 patients). This study confirms the great accuracy and low morbidity of the stereotactic techniques. Computed tomography and magnetic resonance imaging determinate the precise stereotactic coordinates, but in some cases it is necessary to perform stereo-angiography. The stereotactic surgical resection of brain tumors allows the treatment of deep lesions or located at functional areas and considered to be inoperable before. The related literature is discussed.

[Actinomycotic abscess of the cerebellum: a case report]. / Abscesso actinomicótico do cerebelo: relato de caso.

A 38 year-old man presented fever and a clinical picture of intracranial hypertension and ataxic syndrome. A CT-scan disclosed an expanding lesion of the cerebellum. Surgical excision of the lesion was performed and pathological examination made the diagnosis of an actinomycotic abscess. The probable primary source of infection were the lungs and/or oral cavity. The postoperative course was uneventful, with complete recovery after a long period of treatment with penicillin (IV and PO). The authors review some aspects about central nervous system involvement in actinomycosis.

Surgical considerations about the anterior syphon knee of the internal carotid artery. An anatomical study.

An anatomical study about the anterior knee of the intracavernous carotid artery is presented. Twenty cavernous sinuses (CS) were dissected in cadavers using microsurgical techniques. A fibrous ring around the internal carotid artery (ICA) at the CS roof was found in all specimens. This fibrous attachment could be dissected from the surrounding dura and a loose connective tissue could be demonstrated around the ICA. This anatomical finding makes possible the microsurgical approach to vascular lesions of this portion of the ICA, without opening the cavernous sinus.

[Microsurgical treatment of trigeminal neuralgia. A study of 50 cases]. / Traitement microchirurgical de la névralgie du trijumeau. Etude sur 50 cas.

The authors present a study of 50 patients with trigeminal neuralgia treated by posterior fossa microsurgery. Microvascular decompression of the trigeminal nerve was performed in 48 patients. In 2 cases no neuro-vascular compression was found, and a partial rhizotomy was carried out. In 98% of the cases there was postoperative abolition of the pain. Two cases of wound infection and three CSF fistulas were the operative complications. These patients were reoperated and cured. Twenty five patients were reviewed between 13 months and 8 years after surgery. Twenty one remained painfree without any drug, 3 were painfree taking 200 to 400 mg Carbamazepineper day, and 1 patient was reoperated after two years without pain because of recurrence of the neuralgia. There was no mortality or major morbidity in this series. Our results and the literature concerning this method are discussed in this article. In conclusion, microvascular decompression may be indicated in a large number of patients with essential trigeminal neuralgia due to its excellent pain control, no mortality and low morbidity.

Brainstem cysticercosis simulating cystic tumor lesion. A case report.

The authors report the case of a 37 year-old man with a solitary cysticercus cyst in the brainstem (pons) successfully removed through a suboccipital craniectomy. Surgery in neurocysticercosis has been indicated in patients with hydrocephalus and/or large cystic lesions. Cystic lesions in the brainstem and spinal cord may have indication for surgery for two reasons: (1) diagnosis; and (2) treatment. Aspects related to differential diagnosis and therapeutic alternatives are discussed.

[Perimesencephalic subarachnoid hemorrhage nonaneurysmatic: report of a case and literature review]. / Hemorragia subaracnóidea perimesencefálica não-aneurismática. Apresentação de caso e revisão de literatura.

A 42 year-old man with subarachnoid hemorrhage was admitted in our Service (Hunt & Hess grade II). CT-scan disclosed predominantly perimesencephalic subarachnoid hemorrhage. Digital subtraction angiographic study did not disclose either cerebral aneurysm or any other potential site of intracranial bleeding. The evolution was uneventful. A DSA was repeated one month later and was negative. Four months later, the patient was asymptomatic. The authors review the literature and emphasize the importance in recognizing this benign clinical form of nonaneurysmatic subarachnoid hemorrhage.

[Microsurgery of neurovascular decompression for trigeminal neuralgia: study of 35 cases]. / Microcirurgia de descompressão neuro-vascular para neuralgia do trigêmeo. Estudo de 35 casos.

The authors report the study of 35 cases of microvascular decompression for trigeminal neuralgia. No mortality and a very low morbidity were associated with this procedure. The choice of the treatment and the advantages of each method are discussed.

[Stereotaxic biopsy for primary lymphomas of the central nervous system]. / Biópsia estereotáxica para linfomas primários do sistema nervoso central.

Primary lymphomas of the CNS are rare. However the incidence of these lesions has increased recently. These tumors are often situated in the thalamus and basal ganglia, but can be multifocal. The treatment for primary CNS lymphoma is radiotherapy alone or in association with chemotherapy. Because the associated morbidity is very low stereotactic biopsy is an ideal method for determining the histologic diagnosis in patients with suspected CNS lymphoma. The authors present a study of 49 patients with primary CNS lymphomas in which a stereotactic biopsy was performed.