On the role of surface roughness in the corrosion of pure magnesium in vitro.

The relationship between surface roughness and degradation behavior in magnesium (Mg) biomaterials is still a controversial issue. This study aims to clarify the relationship between surface roughness and corrosion rate of pure Mg. Pure Mg samples with surface roughness values (Ra) of 0.59, 2.68, and 9.12 µm were cast using an indirect solid-free form fabrication method. The in vitro corrosion behavior was evaluated using hydrogen evolution, mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. It was confirmed that surface roughness had a significant influence on the corrosion rate of pure Mg, with increasing roughness resulting in an accelerated corrosion rate. However, pitting corrosion was not observed, suggesting that surface roughness does not affect the pitting potential of Mg.

[Intramedullary tumors. Results of a national investigation in private neurosurgery]. / Les tumeurs intramédullaires. Résultat d'une enquête nationale en neurochirurgie libérale.

UNLABELLED: The frequency of intramedullary tumors is 0.5 cases per year for 100,000 inhabitants. The study reported herein was a retrospective study conducted from January 1985 to September 2007. MATERIAL: Seventy-nine cases were distributed in the following manner: ependymomas, 38; astrocytomas, 22; oligodendrogliomas, four; gangliogliomas, two; hemangioblastomas, 10 (nine sporadic cases and one case of Von Hippel-Lindau disease); primitive melanoma, one; and intramedullary neurinomas, two. Three patients were lost to follow-up and 10 patients died. METHOD: All patients were explored using MRI and were operated using a microsurgical technique. Tumor removal was complete in the cases of ependymoma and hemangioblastoma and subtotal in the cases of astrocytoma. RESULTS: Ependymoma: 38 cases with three cases of ependymoblastoma. Mean age: 47 years (range, 17-74 years); 17 males and 21 females. Diagnostic delay: less than one year, 11; one year, 15 cases; two years, nine cases; three years, three cases. Seven recurrences with one 35 years after a prior removal. Localizations: cervical and cervicodorsal, 19; dorsal, ten; dorsolumbar, seven; holomedullary, one. Number of levels concerned: 5-12 (with the cysts associated). Mean follow-up was 10 years (range, two months to 35 years). Patients stabilized, 19; worse, six; improved, nine. Patients deceased: four, one by suicide, three cases of ependymoblastoma (survival, seven months). Astrocytomas: 22 cases, with 14 cases of astrocytoma, two pilocytic astrocytoma, four malignant astrocytoma, and two glioblastoma. Mean age: 44 years (range, 22-73 years); 14 males and eight females. Diagnostic delay: malignant tumors, one to nine months; low grades; three to six years (range, eight months to 25 years). Number of levels concerned: two to eight. Mean follow-up: seven years (range, six months to 10 years). Stabilized patients: 13; worse, five; deaths, four. Oligodendroglioma: four cases. Mean age: 58 years; two males and two females. Diagnostic delay: 10months. Localization: cervical, three; dorsal, one. Oligodendroglioma A, two; B, two. Results: two cases stabilized, one case with recurrence, and one patient deceased. Ganglioglioma: two. Both cases were associated with scoliosis. Recurrence in the eighth month and two years for the second case. One patient died. Hemangioblastoma: 10 cases, nine sporadic and one case of Von Hippel-Lindau disease. Nine cervical localizations, one on the medulla cone. Mean age: 45 years (range, 11-54 years); eight males and two females. Total removal in nine cases. One case of recurrence seven years after a prior surgery and operated a second time with no recurrence after 10 years of follow-up. Intramedullary neurinomas: two cases with a total removal and 15 years of follow-up. Primitive melanoma: one case with mediothoracic location. Treatment with surgery plus radiotherapy. Follow-up, seven years without recurrence. CONCLUSION: Total removal of the intramedullary tumors is a challenge. In cases of removal, the risk of worsening status is 18-19.5%. Subtotal or incomplete removal 27-40% risk of recurrence.

[Pleomorphic adenoma mimicking dacryoadenitis]. / Adénome pléomorphe simulant une dacryoadénite.

A 56-year-old female patient displayed an increased volume of her left lacrimal gland with pain and inflammation. On CT scan, a hyperdense lacrimal mass was found in the left lacrimal fossa. Observation was the first course, for no steroid therapy could be applied because of evolving digestive ulcers. After 9 months of observation, the gland was surgically removed en bloc through a wide anterolateral approach. Pathological analysis of the gland showed a pleomorphic adenoma. This case illustrates the advantage of a wide surgical approach in treating lacrimal gland tumors, in order to avoid or limit the risk of recurrence.

Suboccipital and cervical chordomas: radical resection with vertebral artery control.

OBJECT: Radical resection of chordomas seems to improve a patient's long-term prognosis. At the suboccipital and cervical levels, the vertebral artery (VA) is often considered as a limit in surgical possibilities. The authors report on the management of the VA in a series of 36 patients with chordomas located in the cervical region. METHODS: Over an 11-year period, 36 patients with chordomas located at the suboccipital (28 patients) or cervical (eight patients) level were treated in the authors' neurosurgical department. In 30 patients, the tumors extended laterally toward the VA and required surgical control of the VA. Sixteen of these 30 patients harbored primary tumor, whereas 14 were treated for recurrent disease. The VA was encased in the tumor in 23 patients, with stenosis in six cases. A balloon occlusion test was performed in seven patients and the VA was resected in four. Extensive resection, via a lateral approach on one (22 cases) or on both (eight cases) sides, did not cause any permanent postoperative deficits. In five patients a complementary approach was performed: posterolateral in one and transoral in four. Spinal fixation was performed via the lateral approach (eight cases) or via a complementary posterior approach (five cases). All but two patients underwent radiotherapy, including 10 who underwent proton-beam radiotherapy. CONCLUSIONS: Chordomas extending laterally to the VA can be radically resected via a lateral approach without causing significant morbidity. A complementary approach is often necessary. The best results are achieved in patients with primary compared with recurrent tumor.

Percutaneous jugular placement of ventriculo-atrial shunts using a split sheath. Technical note.

The percutaneous placement of ventriculo-atrial (V-A) shunts for treatment of hydrocephalus has been previously reported by several authors as a simplified procedure. However, this technique did not avoid the use of a distal connector between the outlet catheter and the atrial one, which may lead to a disconnection. A technique of percutaneous V-A shunt insertion using a split sheath is described and illustrated with a series of 22 patients. The use of a split sheath eliminates any distal connector thus avoiding the risk of shunt disconnection and reducing the operating time. The average operating time was 31 min. This rapid procedure allowed us to operate on two of our patients under local anaesthesia. The correct placement of the atrial catheter tip was performed under fluoroscopic control and always confirmed by postoperative radiographs. Two incidents of carotid artery puncture were controlled by simple local compression without further consequences. The mean follow-up time is one year. All the patients' clinical conditions improved. We are encouraged to use this V-A technique more frequently as a method of choice in the treatment of adult hydrocephalus or when the peritoneal cavity is inaccessible in children. The use of a split sheath is successful in reducing the operating time and avoiding the use of a distal connector.