Far lateral approach for intradural tumors at the craniocervical junction

Ventrally placed tumors at the cranio-cervical junctions is a challenging neurosurgical task. The most important factor that influences the surgical outcome in foramen magnum lesions is comprehensive and three-dimensional understanding of the specific anatomy of the region. This study describes in details the far lateral approach for intradural tumors in the craniocervical region, with special emphasis on the management of the vertebral artery and on the anatomic variations encountered in this region. Patients The study included 28 patients with different tumor pathologies in the lateral foramen magnum. All were operated using the far lateral approach to access the lateral angle of the foramen magnum after mobilizing the vertebral artery. The study included 15 cases of ventrally placed meningiomas at the foramen magnum, 7 patients with intra-axial brainstem gliomas, and 6 patients with lower cranial nerve schwanoma. Total excision was achieved in 15 patients, whereas subtotal resection was achieved in thirteen cases. The study included three cases of CSF leakage; one of which needed a secondary dural repair with contimous lumbar drainage. One patient suffered intradural vertebral artery injury in a recurrent meningioma which led to serious morbidity postoperative. Far lateral approach can provide a good working angle to the anterior of the brainstem without extra drilling of the occipital condyle, the aim of surgery at the foramen magnum should be directed at brainstem decompression rather than unsafe total excision of the tumor

Management of adult tethered cord syndrome

This study was done to evaluate the surgical outcome of untethering of the cord in a consecutivec 10 adult patients suffering from tethered cord syndrome. This prospective study was carried out on consecutive 10 adult patients suffering from manifestations due to tethering of the cord. The patients were admitted to the Alexandria main university hospital over a period of 3 years starting from March 2002 to March 2005. The male to female ratio was 7 to 3 and their ages ranged from 25 till 57 years with mean age of 38.5. Most patients [9 patients] suffered from low back pain, while 7 patients showed signs of root affection and radiculopathy, sphincteric disturbances were present in all patients. Interestingly one patient had bilateral neuropathic ulcers at the site of the heel. All our patients developed signs and symptoms of tethered cord syndrome in adulthood. All patients were subjected to preoperative MRI of the lumbosacral spine, urodynamic study, and preoperative electrophysiological study of the lumbo-sacral plexuses. Intraoperative electrophysiological monitoring maneuvers using a bipolar stimulating electrode were used to identify functional neural tissue from the filum terminale and the response of lower limb muscles, and external anal sphincter were recorded either manually or by electromyography. Untethering of the cord using surgical microscope was done under general anesthesia without muscle relaxation. Dural graft was used in one case with secondary adhesions. Mean postoperative follow-up period was 15 months, including both clinical and MRI examination. The lower level of the conus was at lumbar vertebra L2 in one case, at L4 in 6 cases and at level from L5 to sacrum in 3 cases. The tethering lesions were tight filum terminale in 7 patients, lipoma in 2 patients, and secondary adhesions in one patient. Thickness of the filum was ranged from 1 to 7mm with a mean of 3.7mm. There was no operative mortality, and surgery did not provoke any permanent neurological aggravation of our cases. After surgery 2 patients [20%] were asymptomatic, 5 patients [50%] improved, and 3 patients [30%] stabilized, also all the patients were independent. The surgical outcome after tethered cord release in the adults is favorable, as most patients report improvement or stabilization of their symptoms. Safe surgical treatment with minimal complications and side effects can be achieved with the aid of intraoperative neurophysiological monitoring techniques. The success of surgery depends on early diagnosis and complete untethering of the spinal cord. It seems reasonable to recommend early surgical treatment in both symptomatic and asymptomatic adults