Minimally invasive removal of an extradural intraradicular lumbar schwannoma.

OBJECTIVE: Surgical exposure of peripheral lumbar schwannomas often requires extensive muscle mobilization which results in significant postoperative pain. We describe an alternative minimally invasive surgical technique for the treatment of such lesions. METHODS: We report the case of a patient with an extradural intraradicular schwannoma of the L4 root that was treated with a minimally invasive transmuscular approach by using tubular retractors. RESULTS: Muscle trauma and intraoperative blood loss were negligible. The postoperative course was uneventfull. There was no additional morbidity associated with the approach. The patient was discharged 72 h after the procedure. CONCLUSIONS: In selected cases extradural intraradicular lumbar schwannomas can be treated adequately with a minimally invasive transmuscular approach.

Minimally invasive approach for the treatment of lateral lumbar disc herniations. Technique and results.

OBJECTIVE: This paper aims to demonstrate the feasibility and efficacy of a minimal invasive approach by using a muscle dilator system for the treatment of lateral lumbar disc herniations. METHODS: A retrospective analysis of 38 cases with lateral lumbar disc herniations that were treated the METRx-System was performed. Patients were assessed preoperatively and postoperatively with the visual analogue scale (VAS) for leg pain. Follow up ranged from 6 to 24 months. RESULTS: No intraoperative complications were observed. Operation time and intraoperative blood loss were minimized. In 37 cases VAS scores were significantly lower after the procedure. A single patient had to be reoperated due to insufficient removal of the herniated disc material. CONCLUSION: The reported minimal invasive technique is a safe and efficient alternative to conventional methods for the treatment of lateral lumbar disc herniations.

Benefits and limitations of image guidance in the surgical treatment of intracranial dural arteriovenous fistulas.

BACKGROUND: Despite major advances in endovascular embolization techniques, microsurgical resection remains a reliable and effective treatment modality for dural arteriovenous fistulas (DAVF). However, intraoperative detection of these lesions and identification of feeding arteries and draining veins can be challenging. In a series of 6 patients who were not candidates for definitive treatment by endovascular embolization we evaluated the benefits and limitations of computer-assisted image guidance for surgical ablation of DAVF. METHODS: Of the 6 patients, 5 presented with haemorrhage and one with seizures. Diagnosis of DAVF was made by conventional angiography and dynamic contrast enhanced MR angiography (CE-MRA). All patients were surgically treated with the assistance of a 3D high resolution T1-weighted MR data set and time-of-flight MR angiography (MRA) obtained for neuronavigation. Registration was based on cranial fiducials and image-guided surgery was performed with the navigation system. FINDINGS: Four of the 6 patients suffered from DAVF draining into the superior sagittal sinus, one fistula drained into paracavernous veins adjacent to the superior petrosal sinus and one patient had a pial fistula draining in the straight sinus. DAVF diagnosed with conventional angiography could be located on CE-MRA and MRA prior to surgery. MRI and MRA images were combined on the neuronavigation workstation and DAVF were located intraoperatively by using a tracking device. In 4 out of 6 cases neuronavigation was used for direct intraoperative identification of DAVF. Brain shift prevented direct tracking of pathological vessels in the other 2 cases, where navigation could only be used to assist craniotomy. Microsurgical dissection and coagulation of the fistulas led to complete cure in all patients as confirmed by angiography. CONCLUSIONS: Neuronavigation may be used as an additional tool for microsurgical treatment of DAVF. However, in this small series of 6 cases, surgical procedures have not been substantially altered by the use of the neuronavigation system. Image guidance has been beneficial for the location of small, superficially located DAVF, whereas a navigated approach to deep-seated lesions was less accurate due to the familiar problem of brain shift and brain retraction during surgery.

Neurosurgical interventions during pregnancy and the puerperium: clinical considerations and management.

Neurosurgical interventions during pregnancy represent a special clinical challenge and require a meticulously selected treatment strategy. A thorough understanding of the underlying pathophysiological mechanisms involving mother and fetus is mandatory. We report our experience with neurosurgical procedures during pregnancy and the puerperium and summarize the difficulties encountered. The emerging diagnostic as well as therapeutic implications in these complex cases are also discussed.

Neurosurgical interventions in children with Maroteaux-Lamy syndrome. Case report and review of the literature.

This paper reports the case of a 14-year-old child with Maroteaux-Lamy syndrome (mucopolysaccharidosis type 6) who was treated consecutively for compressive damage of the optic nerves, hydrocephalus communicans and progressive spastic tetraparesis within 2 years. The clinical course of the patient is presented and the pathophysiologic mechanisms of disease progression in patients with Maroteaux-Lamy syndrome are discussed and reviewed.

Effects of the immunomodulator linomide on macrophage migration and myelin phagocytic activity in peripheral nerve trauma: an experimental study.

Wallerian degeneration after peripheral nerve transection leads to the phagocytosis of degenerated myelin and axon components by macrophages. These phagocytes are recruited from the systemic circulation and Wallerian degeneration may therefore be used as a model for myelin removal by hematogenous macrophages, a feature that is also a hallmark of demyelinating diseases of the central and peripheral nervous system. The immunomodulator linomide has been shown to be effective in the treatment of experimental demyelinating diseases although the exact mode of its action is not yet defined. The present study investigated the effect of linomide on monocyte invasion and myelin phagocytosis after sciatic nerve transection. Linomide had a dual effect in Wallerian degeneration. Monocyte migration from the circulation to the damaged nervous system was significantly reduced. Additionally, the myelin phagocytic capacity of macrophages was impaired, finally resulting in a significant delay in the removal of myelin. The present experiments may provide an explanation for the effects of linomide during the course of demyelinating diseases of the nervous system.

Involvement of intercellular adhesion molecule-1 in myelin recognition by macrophages.

Macrophages play a crucial role in myelin removal during nerve degeneration and demyelination. The exact mechanisms of myelin recognition and uptake are not yet defined. The present experiments aimed at defining the role of intercellular adhesion molecule-1 (ICAM-1) in this process. Myelin phagocytosis was studied in an established in vitro model of cultured macrophages and sciatic nerves. Cocultures of wild-type C57BL macrophages with sciatic nerves resulted in a massive invasion of the nerves by macrophages with subsequent removal of myelin. In contrast, when macrophages of ICAM-1-deficient animals were cocultured with wild-type nerves, myelin phagocytosis was significantly retarded, whereas cell invasion was completely undisturbed. These data indicate that the ICAM-1 molecule acts as a costimulatory signal in myelin recognition and uptake by macrophages.

Wallerian degeneration in ICAM-1-deficient mice.

Wallerian degeneration of the peripheral nervous system was studied in ICAM-1-deficient mice and compared with the phenomena observed in C57BL wild-type animals. There was a decrease in myelin density in both mice strains 4 and 6 days after transection of the sciatic nerve. The degenerating nerves were invaded by Mac-1-, LFA-1-, and F4/80-positive macrophages; significantly lower numbers of macrophages were present in ICAM-1-deficient nerves. Myelin loss decreased after nerve transection with a more prominent loss in ICAM-1-deficient animals. Schwann cells revealed a much higher myelin load in these animals when compared with wild-type nerves, and there was an increased proliferation of endoneurial cells in ICAM-1-deficient mice. These data indicate that ICAM-1 is involved in macrophage recruitment to injured peripheral nerves as well as in the proliferative and phagocytic response of Schwann cells after peripheral nerve transection.