A basic model for practice of intracranial microsurgery.

BACKGROUND: Intracranial microsurgical procedures often take place in a deep location, with a limited access space, necessitating the use of long knee-bend instruments and limiting the degree of movement. We devised an easily accessible model that allows the neurosurgical trainee to gain familiarity with intracranial microsurgical techniques. METHODS: The model consists of a pedestal, on which 2 movable vices are placed. The object to be practiced on can be placed on a working area, or the vices may hold the object. The pedestal can be covered by a box with a centered hole. When using this box, the vices can move together in the vertical plane over a trajectory of 5.5 cm to simulate superficial or deep microsurgical procedures. To simulate several sizes of hypothetical craniotomies, 3 rings can be used to decrease the diameter of centered hole in the box. RESULTS: Using the model, these techniques were judged to be technically more challenging and difficult to execute through the centered hole. CONCLUSIONS: Our model can be a useful method to train for basic intracranial microsurgery.

Repeated surgery for glioblastoma multiforme: only in combination with other salvage therapy.

BACKGROUND: The purpose of the study was to evaluate the effects, frequency, and complications of repeated surgical resection for GBM relapse. METHODS: A group of 32 patients with tumor recurrence, derived from a total of 126 consecutive patients with prior GBM, treated between 1999 and 2005 in the VU University Medical Center, Amsterdam, Netherlands, were retrospectively studied. Survival, functional status, morbidity, and mortality after starting salvage therapy for recurrent GBM were studied. Survival was analyzed using Kaplan-Meier survival curves, and log-rank statistics were used for group comparison. RESULTS: Of the 32 patients with recurrent primary GBM, 20 received repeated surgery as salvage therapy. In 11 (55%) cases, repeated surgery was followed by CT or SRS. Nine (45%) patients receiving only repeated surgery showed significantly lower survival rates compared with the aforementioned 11 cases. The remaining 12 patients received only salvage CT or SRS and showed a significantly prolonged survival compared with the 9 cases receiving repeated surgery only. Surgical morbidity was 15%, and surgical mortality, 5%. CONCLUSION: Despite inherent selection bias, this retrospective analysis suggests that repeated surgery for GBM relapse should only be considered in patients with severe symptoms and if additional salvage treatment can be administered postoperatively.

Atypical transformation in sacral drop metastasis from posterior fossa choroid plexus papilloma.

Choroid plexus papillomas (CPP) are rare tumours and spinal metastases of CPP are even less common. We report a 50-year-old woman with spinal drop metastases at Th9 and S1-2 6 years after total resection of a posterior fossa CPP. The metastasis at S1-2 was resected and histological examination showed transformation to an atypical CPP. Atypical transformation in a metastasis years after resection of a benign posterior fossa CPP has been described once. We would like to advocate craniospinal MRI at the time of initial diagnosis as well as periodic follow-up after total and subtotal resection of a posterior fossa CPP in adults at least once in 1 or 2 years, depending on the histological grading of the primary CPP. In our case report, this could have resulted in earlier diagnosis of the locoregional recurrence or of the spinal drop metastasis.

Stereotactic radiation therapy for large vestibular schwannomas.

BACKGROUND AND PURPOSE: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. MATERIAL AND METHODS: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger), treated with stereotactic radiotherapy (SRT) or stereotactic radiosurgery (SRS) between 1992 and 2007, were retrospectively studied after a mean follow-up period of three years with respect to tumor-control rate and complications. RESULTS: Actuarial 5-year maintenance of pre-treatment hearing level probability of 30% was achieved. Five of 17 patients suffered permanent new facial nerve dysfunction. The actuarial 5-year facial nerve preservation probability was 80%. Permanent new trigeminal nerve neuropathy occurred in two of 15 patients, resulting in an actuarial 5-year trigeminal nerve preservation probability of 85%. Tumor progression occurred in four of 25 (16%) patients. The overall 5-year tumor control probability was 82%. CONCLUSION: Increased morbidity rates were found in patients with large VS treated with SRT or SRS compared to the published series on regular sized VS and other smaller retrospective studies on large VS.