Neurosurg Focus
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Spinal pseudomeningoceles and cerebrospinal fluid (CSF) fistulas are uncommon extradural collections of CSF that may result from inadvertent tears in the dural-arachnoid layer, traumatic injury, or may be congenital in origin. Most pseudomeningoceles are iatrogenic and occur in the posterior lumbar region following surgery. The true incidence of iatrogenic pseudomeningoceles following laminectomy or discectomy is unknown; however, the authors of several published reports suggest that the incidence of lumbar pseudomeningoceles following laminectomy or discectomy is between 0.07% and 2%. ⋯ Although magnetic resonance imaging is the neurodiagnostic study of choice, computerized tomography myelography and radionuclide myelographic study may be helpful diagnostic tools in some cases. Analysis of suspect fluid for Beta2 transferrin may be a useful adjunctive study. Treatment options include close observation for spontaneous resolution, conservative measures such as bed rest and application of an epidural blood patch, lumbar subarachnoid drainage, and definitive surgical repair.
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Spontaneous intracranial hypotension has become a well-recognized clinical entity, but it remains an uncommonly, and probably underdiagnosed, cause of headache; its estimated prevalence is only one in 50,000 individuals. The clinical spectrum of spontaneous intracranial hypotension is quite variable and includes headache, neck stiffness, cranial nerve dysfunction, radicular arm pain, and symptoms of diencephalic or hindbrain herniation. Leakage of the spinal cerebrospinal fluid (CSF) is the most common cause of spontaneous intracranial hypotension. ⋯ The initial treatment of choice is a lumbar epidural blood patch, regardless of the location of the CSF leak. If the epidural blood patch fails, the blood patch procedure can be repeated at the lumbar level, or a blood patch can be directed at the exact site of the leak. Surgical repair of the CSF leak is safe and generally successful, although a distinct structural cause of the leak often is not found.
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Thoracic disc herniation has always carried with it the potential for serious adverse neurological consequences if not treated appropriately. The authors review the historical evolution of treatment for thoracic disc herniation from the early surgical series using dorsal approaches (which were known to involve a significant risk of paraplegia) to later surgical series in which lateral and then ventral approaches to the disc were increasingly emphasized, with significant improvement in patient outcome. The evolution of minimally invasive thoracoscopic techniques is discussed, together with the results of several surgical series demonstrating significant reductions in morbidity compared with more traditional methods. The technique of thoracoscopic discectomy is presented in detail.
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The transthoracic approach to herniated thoracic discs is an important procedure in the management of these uncommonly encountered lesions. Whereas posterior and posterolateral microsurgical approaches and thoracoscopic procedures have been widely advocated in the recent neurosurgical literature, the transthoracic operation continues to offer significant advantages in appropriately selected cases. The authors discuss the preoperative considerations, relevant anatomical structures, and surgical technique.
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Thoracoscopic discectomy is a minimally invasive procedure simulating a thoracotomy and is an alternative to the costotransversectomy and transpedicular approaches. In recent studies authors have concluded that thoracoscopic discectomy is the preferred procedure; however, relative historical comparisons were difficult to interpret. The authors conducted a prospective nonrandomized study in which they compared data on 36 patients undergoing thoracoscopic discectomy with eight patients undergoing thoracotomy between 1995 and 1999. ⋯ One advantage to thoracoscopic discectomy is its reduced incidence of morbidity compared with thoractomy, but its steep learning curve and unfamiliar surgical techniques make this procedure less practical for surgeons not performing it frequently. The more familiar costotransversectomy, transpedicular, and thoracotomy procedures remain viable alternatives for surgeons more experienced in these procedures.