Minimally invasive interbody fusion for revision lumbar surgery: technical feasibility and safety.

STUDY DESIGN: Retrospective chart review of one surgeon's practice. OBJECTIVE: We evaluate the perioperative morbidity of 43 patients undergoing minimally invasive lumbar interbody fusion to differentiate risks between primary and revision surgery candidates. SUMMARY OF BACKGROUND DATA: Minimally invasive approaches to the lumbar spine have rapidly evolved and the technical feasibility and safety of minimally invasive interbody fusion is well established. Revision surgery is technically more challenging and may cause avoidance of such approaches because of altered anatomy and absent bony landmarks. Description of minimally invasive surgery approaches among revision patients and the feasibility of such techniques demands clarification. METHODS: Forty-three consecutive minimally invasive transforaminal lumbar interbody fusions (TLIFs) and posterior lumbar interbody fusions (PLIFs) were reviewed. Estimated blood loss, operative time, and complication rates were compared between primary and revision patients using Student t tests. RESULTS: Seventeen revision surgery cases (40%) were compared with 26 primary surgeries (60%) to elucidate differences in operative time, estimated blood loss, and complications. Demographic variables were similar in both groups. Estimated blood loss trended higher among the PLIF group and among revision cases, though no statistical significance was observed. A higher rate of complications, most notably incidental durotomy, was observed among revision cases in both PLIF and TLIF patients. One patient undergoing primary surgery had an intraoperative pedicle fracture, and 1 patient undergoing revision surgery had an asymptomatic screw malposition. No patients had a major complication, nerve injury, infection, or conversion to an open procedure. CONCLUSIONS: Minimally invasive lumbar interbody fusion by revision surgery is technically feasible and is not associated with more blood loss or neurologic morbidity. However, revision surgery has a higher minor perioperative complication rate, particularly of incidental durotomy. These outcomes demand significant experience before attempting minimally invasive revision surgery in the lumbar spine.

Molecular strategies for the treatment of malignant glioma--genes, viruses, and vaccines.

The standard treatment paradigm of surgery, radiation, and chemotherapy for malignant gliomas has only a modest effect on survival. It is well emphasized in the literature that despite aggressive multimodal therapy, most patients survive approximately 1 year after diagnosis, and less than 10% survive beyond 2 years. This dismal prognosis provides the impetus for ongoing investigations in search of improved therapeutics. Standard multimodal therapy has largely reached a plateau in terms of effectiveness, and there is now a growing body of literature on novel molecular approaches for the treatment of malignant gliomas. Gene therapy, oncolytic virotherapy, and immunotherapy are the major investigational approaches that have demonstrated promise in preclinical and early clinical studies. These new molecular technologies each have distinct advantages and limitations, and none has yet demonstrated a significant survival benefit in a phase II or III clinical trial. Molecular approaches may not lead to the discovery of a "magic bullet" for these aggressive tumors, but they may ultimately prove synergistic with more conventional approaches and lead to a broadening of the multimodal approach that is the current standard of care. This review will discuss the scientific background, therapeutic potential, and clinical limitations of these novel strategies with a focus on those that have made it to clinical trials.

Spinal capillary hemangioma in infants: report of two cases and review of the literature.

We report the case of 2 infants born with a lumbar dermal sinus tract and an overlying angiomatous skin lesion referred to our pediatric neurosurgery service for evaluation of a tethered cord. Both infants were born with a lumbar dimple and were found to have a large cutaneous hemangioma without neurologic symptoms. An MRI of the lumbar spine revealed an isointense mass in the dorsal epidural at L(4) with an adjacent mass effect and extension into the overlying soft tissues. The spinal cord also appeared to be tethered with a fatty filum terminale. We performed a lumbar laminectomy and laminoplasty to remove the mass and to release the tethered cord. Pathologic examination confirmed the diagnosis of capillary hemangioma. Several case reports describe spinal capillary hemangiomas in adults, but only one found in the literature describes a case in an infant. We provide a review of the literature of spinal capillary hemangiomas and support the practice of evaluating infants with cutaneous lumbosacral hemangiomas for underlying spinal cord abnormalities.

Cerebellar cryptococcoma in a patient with undiagnosed sarcoidosis: case report.

OBJECTIVE: We describe a patient with undiagnosed sarcoidosis who presented with a rare isolated cerebellar cryptococcoma masquerading as a metastatic brain tumor. CLINICAL PRESENTATION: A 58-year-old man with a history of resected squamous cell carcinoma of the larynx and pulmonary nodules was found to have a left cerebellar lesion on neuroimaging after presenting with a 4-month history of occipital headaches. Neuroimaging revealed a large, lobulated, intra-axial, left cerebellar hemispheric mass with peripheral nodular enhancement, mild adjacent edema, and dense focal areas of calcification. INTERVENTION: The patient underwent a left suboccipital craniotomy for gross total resection of the left cerebellar mass. Pathological examination of the resected specimen demonstrated a cryptococcoma, which was confirmed with a positive cerebrospinal fluid cryptococcal antigen. Postoperative evaluation revealed pulmonary sarcoidosis. CONCLUSION: Central nervous system cryptococcoma is a rare infection that may present in a patient with no known history of immunosuppression and no clinical signs of infection. Diagnostically, this can be difficult to distinguish from a brain tumor. Central nervous system cryptococcoma is an opportunistic infection that typically occurs in the presence of an immunosuppressed state. Sarcoidosis should be considered a predisposing factor because patients with this underlying disease have an increased susceptibility to this central nervous system fungal infection.

Primary spinal intramedullary adrenal cortical adenoma associated with spinal dysraphism: case report.

OBJECTIVE: The authors report a primary spinal intramedullary adrenal cortical adenoma in a patient with spinal dysraphism presenting with bilateral leg pain and urinary frequency. METHODS: Magnetic resonance imaging, L2 laminectomy with resection of mass, and pathological and immunohistochemical analysis of resected mass revealed the diagnosis. RESULTS: Microscopic and immunohistochemical findings confirmed the diagnosis as a primary intramedullary tumor of adrenal cortical origin. CONCLUSION: The occurrence of a primary adrenal tumor in the spinal cord is rare and difficult to explain based on our understanding of embryology. A review of the relevant literature and discussion of the pathophysiology and clinical implications is provided.

Capillary hemangioma of the fourth ventricle in an infant. Case report and review of the literature.

A 3-month-old boy presented to the pediatric neurosurgery service with central hypotonia. Magnetic resonance images of the brain revealed a homogeneously enhancing dumbbell-shaped mass located in the fourth ventricle and extending into the left cerebellopontine angle (CPA). A suboccipital craniotomy was performed and a gross-total resection of the mass was achieved. Pathological examination of the resected tissue confirmed the diagnosis of capillary hemangioma. To the authors' knowledge, this is the first reported case of a capillary hemangioma occurring in this location. The authors provide a review of the current literature on intracranial capillary hemangiomas and conclude that, despite the rarity of these lesions, they should be considered in the differential diagnosis of lesions in the fourth ventricle and/or the CPA in children.

An eclectic history of peripheral nerve surgery.

It is hard to decide where history stops and contemporary development of peripheral nerve surgery begins. This article provides an eclectic view of the history of peripheral nerve surgery. In trying to keep the story moving, the publications of many authors have been omitted. For this, we are sorry. We have also stopped short of reporting the contemporary history of molecular biology as applied to peripheral nerve regeneration. The future of peripheral nerve repairs lies in our understanding of the molecular cascades that stimulate axon growth and guide the axon to its proper destination. We hope that this review shows the reader that researchers who got us where we are traveled a road filled with erroneous dogma, bad advice,and misleading data. We believe that the lessons learned from those who brought us back to the right path are applicable to many disciplines.